Biomedical subjects

T C Johnson

Publications and source records attributed to T C Johnson.

At least 19 recordsLinked to original sources

PubMed2006

Spinal manipulation for primary and secondary dysmenorrhoea.

BACKGROUND: Dysmenorrhoea refers to the occurrence of painful menstrual cramps of uterine origin and is a common gynaecological condition. One possible treatment is spinal manipulation therapy. One hypothesis is that mechanical dysfunction in certain vertebrae causes decreases spinal mobility. This could affect the sympathetic nerve supply to the blood vessels supplying the pelvic viscera, leading to dysmenorrhoea as a result of vasoconstriction. Manipulation of these vertebrae increases spinal mobility and may improve pelvic blood supply. Another hypothesis is that dysmenorrhoea is referred pain arising from musculoskeletal structures that share the same pelvic nerve pathways. The character of pain from musculoskeletal dysfunction can be very similar to gynaecological pain as it can present as cyclic pain altered by hormonal influences associated with menstruation. OBJECTIVES: To determine the safety and efficacy of spinal manipulative interventions for the treatment of primary or secondary dysmenorrhoea when compared to each other, placebo, no treatment, or other medical treatment. SEARCH STRATEGY: We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (searched April 2006), CENTRAL (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to March 2006), EMBASE (1980 to April 2006), CINAHL (1982 to March 2006), AMED (1985 to April 2006), Biological Abstracts (1969 to March 2006), PsycINFO (1806 to April 2006), and SPORTDiscus (1830 to April 2006). Attempts were also made to identify trials from the metaRegister of Controlled Trials and the citation lists of review articles and included trials. In most cases the first or corresponding author of each included trial was contacted for additional information. SELECTION CRITERIA: Any randomised controlled trials (RCTs) including spinal manipulative interventions (for example chiropractic, osteopathy, or manipulative physiotherapy) versus each other, placebo, no treatment, or other medical treatment were considered. Exclusion criteria were: mild or infrequent dysmenorrhoea or dysmenorrhoea from an intrauterine device (IUD). DATA COLLECTION AND ANALYSIS: Four trials of high velocity, low amplitude manipulation (HVLA), and one of the Toftness manipulation technique were included. Quality assessment and data extraction were performed independently by two review authors. Meta analysis was performed using odds ratios for dichotomous outcomes and weighted mean differences for continuous outcomes. Data unsuitable for meta-analysis were reported as descriptive data and were also included for discussion. The outcome measures were pain relief or pain intensity (dichotomous, visual analogue scales, descriptive) and adverse effects. MAIN RESULTS: Results from the four trials of high velocity, low amplitude manipulation suggest that the technique was no more effective than sham manipulation for the treatment of dysmenorrhoea, although it was possibly more effective than no treatment. Three of the smaller trials indicated a difference in favour of HVLA, however the one trial with an adequate sample size found no difference between HVLA and sham treatment. There was no difference in adverse effects experienced by participants in the HVLA or sham treatment. The Toftness technique was shown to be more effective than sham treatment by one small trial, but no strong conclusions could be made due to the small size of the trial and other methodological considerations. AUTHORS' CONCLUSIONS: Overall there is no evidence to suggest that spinal manipulation is effective in the treatment of primary and secondary dysmenorrhoea. There is no greater risk of adverse effects with spinal manipulation than there is with sham manipulation.

Dysmenorrhea↗

PubMed2005

The rate of treatment of chronic hepatitis C in patients co-infected with HIV in an urban medical centre.

Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection is common. HIV co-infection results in a higher rate of histologic progression and shorter interval to HCV-related cirrhosis. Successful treatment of HCV with interferon-based therapy reduces the morbidity and mortality of patients. Significant factors may limit the availability of treatment in co-infected patients. The rate of treatment of HCV and limiting factors to treatment in a co-infected population in an urban setting were determined. A retrospective review of co-infected patients was conducted at our liver and gastrointestinal (GI) clinics for treatment of HCV from July 2001 to June 2002. Treatment of HCV and reasons for nontreatment were recorded. A total of 104 HCV/HIV co-infected patients were identified. Seventy-two per cent were males. Mean age was 47.2 years (32-72). Seventy-four of the 82 (90%) with identifiable risk factors for HCV infection had a history of intravenous drug use (IVDU). Twenty per cent (21/104) of the total underwent a liver biopsy. Sixty-seven per cent who had a liver biopsy were treated. Overall, sixteen patients were treated. Eighty-eight (85%) patients were not treated for the following reasons: 13 refused treatment, and 75 were ineligible. Of the ineligible patients, 40% were noncompliant with visits, 15% were active substance abusers, 13% had decompensated cirrhosis, 8% had significant active psychiatric conditions and 24% had significant co-morbid disease. A majority of patients co-infected with HCV/HIV had a IVDU history. Most co-infected patients were not eligible for HCV treatment. A majority of noncandidates had potentially modifiable psychosocial factors leading to nontreatment.

Adult↗

PubMed2004

Spinal manipulation for primary and secondary dysmenorrhoea.

BACKGROUND: Dysmenorrhoea refers to the occurrence of painful menstrual cramps of uterine origin and is a common gynaecological condition. One possible treatment is spinal manipulation therapy. One hypothesis is that mechanical dysfunction in certain vertebrae causes decreased spinal mobility. This could affect the sympathetic nerve supply to the blood vessels supplying the pelvic viscera, leading to dysmenorrhoea as a result of vasoconstriction. Manipulation of these vertebrae increases spinal mobility and may improve pelvic blood supply. Another hypothesis is that dysmenorrhoea is referred pain arising from musculoskeletal structures that share the same pelvic nerve pathways. The character of pain from musculoskeletal dysfunction can be very similar to gynaecological pain and can present as cyclic pain as it can also be altered by hormonal influences associated with menstruation. OBJECTIVES: To determine the safety and efficacy of spinal manipulative interventions for the treatment of primary or secondary dysmenorrhoea when compared to each other, placebo, no treatment, or other medical treatment. SEARCH STRATEGY: We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched 18 March 2004), CENTRAL (The Cochrane Library Issue 1, 2004), MEDLINE (1966 to March 2004), EMBASE (1980 to March 2004), CINAHL (1982 to March 2004), AMED (1985 to March 2004), Biological Abstracts (1969 to Dec 2003), PsycINFO (1872 to March 2004) and SPORTDiscus (1830 to March 2004). The Cochrane Complementary Medicine Field's Register of controlled trials (CISCOM) was also searched. Attempts were also made to identify trials from the metaRegister of Controlled Trials and the citation lists of review articles and included trials. In most cases, the first or corresponding author of each included trial was contacted for additional information. SELECTION CRITERIA: Any randomised controlled trials (RCTs) including spinal manipulative interventions (e.g. chiropractic, osteopathy or manipulative physiotherapy) vs each other, placebo, no treatment, or other medical treatment were considered. Exclusion criteria were: mild or infrequent dysmenorrhoea or dysmenorrhoea from an IUD. DATA COLLECTION AND ANALYSIS: Four trials of high velocity, low amplitude manipulation (HVLA), and one of the Toftness manipulation technique were included. Quality assessment and data extraction were performed independently by two reviewers. Meta analysis was performed using odds ratios for dichotomous outcomes and weighted mean differences for continuous outcomes. Data unsuitable for meta-analysis were reported as descriptive data and were also included for discussion. The outcome measures were pain relief or pain intensity (dichotomous, visual analogue scales, descriptive) and adverse effects. MAIN RESULTS: Results from the four trials of high velocity, low amplitude manipulation suggest that the technique was no more effective than sham manipulation for the treatment of dysmenorrhoea, although it was possibly more effective than no treatment. Three of the smaller trials indicated a difference in favour of HVLA, however the one trial with an adequate sample size found no difference between HVLA and sham treatment. There was no difference in adverse effects experienced by participants in the HVLA or sham treatment. The Toftness technique was shown to be more effective than sham treatment by one small trial, but no strong conclusions could be made due to the small size of the trial and other methodological considerations. REVIEWERS' CONCLUSIONS: Overall there is no evidence to suggest that spinal manipulation is effective in the treatment of primary and secondary dysmenorrhoea. There is no greater risk of adverse effects with spinal manipulation than there is with sham manipulation.

Dysmenorrhea↗

PubMed2001

Spinal manipulation for primary and secondary dysmenorrhoea.

BACKGROUND: Dysmenorrhoea refers to the occurrence of painful menstrual cramps of uterine origin and is a common gynaecological condition. The efficacy of medical treatments such as nonsteroidal anti-inflammatories (NSAIDs) or oral contraceptive pills (OCPs) is considerable, however the failure rate can still be as high as 20-25% and there are also a number of associated adverse effects. Many women are thus seeking alternatives to conventional medicine. One popular treatment modality is spinal manipulation therapy. There are several rationales for the use of musculoskeletal manipulation to treat dysmenorrhoea. The parasympathetic and sympathetic pelvic nerve pathways are closely associated with the spinal vertebrae, in particular the 2nd-4th sacral segments and the 10th thoracic to the 2nd lumbar segments. One hypothesis is that mechanical dysfunction in these vertebrae causes decreased spinal mobility. This could affect the sympathetic nerve supply to the blood vessels supplying the pelvic viscera, leading to dysmenorrhoea as a result of vasoconstriction. Manipulation of these vertebrae increases spinal mobility and may improve pelvic blood supply through an influence on the autonomic nerve supply to the blood vessels. Another hypothesis is that dysmenorrhoea is referred pain arising from musculoskeletal structures that share the same pelvic nerve pathways. The character of pain from musculoskeletal dysfunction can be very similar to gynecological pain and can present as cyclic pain as it can also be altered by hormonal influences associated with menstruation. OBJECTIVES: To determine the safety and efficacy of spinal manipulative interventions for the treatment of primary or secondary dysmenorrhoea when compared to each other, placebo, no treatment, or other medical treatment. SEARCH STRATEGY: Electronic searches of the Cochrane Menstrual Disorders and Subfertility Group specialised register of controlled trials, CCTR, MEDLINE, EMBASE, CINAHL, Bio extracts, Psyclit and SPORTDiscus were performed to identify relevant randomised controlled trials (RCTs). The Cochrane Complementary Medicine Field's Register of controlled trials (CISCOM) was also searched. Attempts were also made to identify trials from the National Research Register, the Clinical Trial Register and the citation lists of review articles and included trials. In most cases, the first or corresponding author of each included trial was contacted for additional information. SELECTION CRITERIA: Any RCTs including spinal manipulative interventions (e.g. chiropractic, osteopathy or manipulative physiotherapy) vs each other, placebo, no treatment, or other medical treatment were considered. Exclusion criteria were: mild or infrequent dysmenorrhoea or dysmenorrhoea from an IUD. DATA COLLECTION AND ANALYSIS: Five RCTs were identified that fulfilled the inclusion criteria for this review. Four trials involving high velocity, low amplitude manipulation (HVLA), and one involving the Toftness manipulation technique were included. Quality assessment and data extraction were performed independently by two reviewers. Meta analysis was performed using odds ratios for dichotomous outcomes and weighted mean differences for continuous outcomes. Data unsuitable for meta-analysis were reported as descriptive data and were also included for discussion. The outcome measures were pain relief or pain intensity (dichotomous, visual analogue scales, descriptive) and adverse effects. MAIN RESULTS: Results from the four trials of high velocity, low amplitude manipulation suggest that the technique was no more effective than sham manipulation for the treatment of dysmenorrhoea, although it was possibly more effective than no treatment. Three of the smaller trials indicated a difference in favour of HVLA, however the one trial with an adequate sample size found no difference between HVLA and sham treatment. There was no difference in adverse effects experienced by participants in the HVLA or sham treatment. The Toftness technique was shown to be more effective than sham treatment by one small trial, but no strong conclusions could be made due to the small size of the trial and other methodological considerations. REVIEWER'S CONCLUSIONS: Overall there is no evidence to suggest that spinal manipulation is effective in the treatment of primary and secondary dysmenorrhoea. There is no greater risk of adverse effects with spinal manipulation than there is with sham manipulation.

Dysmenorrhea↗

PubMed2001

Physical fitness and self-reported physical exercise among college men and women in 1987 and 1997.

The study examined the relations of self-reported physical activity levels and physical fitness scores for two samples of college students assessed in 1987 (n = 261) and in 1997 (n = 243). Significantly greater exercise was reported by the 1997 women than the 1987 women; amount of exercise reported by men did not differ. For both samples, greater exercise was associated with increased fitness for women and men as assessed by the Hall 1986 Physical Fitness Test Profile, comprised of measures on body fat composition; grip strength; muscle endurance, flexibility, resting heart rate; systolic and diastolic blood pressures; and aerobic power. For the 1987 sample men were more fit than women. For the 1997 sample, women were more fit than men. The 1997 women were more fit than the 1987 women; there was no difference on overall fitness measures of the two samples of men.

Adult↗

PubMed2000

CeReS-18, a cell regulatory sialoglycopeptide, inhibits proliferation and migration of rat vascular smooth muscle cells.

CeReS-18, a cell regulatory sialoglycopeptide, has been shown to inhibit proliferation of a wide array of target cells. In the present study, the effect of CeReS-18 on vascular smooth muscle cell (SMC) proliferation was characterized in cultured rat aorta SMCs (A7r5). More extensively, the effect of CeReS-18 on platelet-derived growth factor (PDGF)-induced SMC migration was examined using a modified Boyden's chamber assay. CeReS-18 inhibits both SMC proliferation and migration in a concentration-dependent, calcium-sensitive, and reversible manner. Furthermore, cells preincubated with the inhibitor had an increased sensitivity to CeReS-18-mediated inhibition of SMC migration. Immunoprecipitation and in vitro phosphorylation assays demonstrated that MAP kinase activity was inhibited in the CeReS-18-treated cells and pretreatment with CeReS-18 suppressed the activation of MAP kinase stimulated by PDGF. However, it is not likely that the suppression of the MAP kinase pathway was directly responsible for the ability of CeReS-18 to inhibit migration of the rat aorta smooth muscle cells since a MEK-specific inhibitor, PD98059, did not influence A7r5 cell migration.

Animals↗

PubMed2000

Improved post-embedding immunocytochemistry of myelinated nervous tissue for electron microscopy.

The particularly high lipid content of normal mature adult myelin sheaths, together with the light fixation protocols usually necessary to retain antigenicity, combine to make white matter nervous tissue an especially problematical subject for post-embedding immuno-electron microscopy using modern acrylic resins. Fixation and infiltration modifications to standard processing schedules for Lowicryl were found to greatly improve the embedding and therefore the resulting morphology. This in turn improved the signal to noise ratio by reducing the high non-specific backgrounds usually found in poorly infiltrated areas. Using Lowicryl HM20, we have been able to obtain satisfactory immunostaining for myelin basic protein with good retention of structural integrity in the myelin of both normal and lesioned adult cortico spinal tract.

Animals↗

PubMed2000

Osteonecrosis of the knee after arthroscopic surgery for meniscal tears and chondral lesions.

PURPOSE: Avascular necrosis of the knee following arthroscopic surgery has been described. The purpose of this article is to report a large series of patients who developed avascular necrosis after arthroscopy of the knee in an effort to delineate casual factors and results of treatment. TYPE OF STUDY: Case series. METHODS AND MATERIALS: The charts, radiographs, and magnetic resonance imaging (MRI) scans of patients who developed osteonecrosis (ON) of the knee after routine arthroscopic surgery were reviewed. Only those patients with no evidence of ON on preoperative MRI performed 6 weeks or longer after symptom onset and who postoperatively developed ON confirmed by repeat MRI and/or by pathological testing (specimens obtained at subsequent total knee arthroplasty) were included in the study. Seven patients with average age of 60 years (range, 41 to 79 years) met these inclusion criteria. RESULTS: The lesions noted at arthroscopy included 4 medial meniscus tears, 3 lateral meniscal tears, 6 chondromalacia of the medial femoral condyle, 2 chondromalacia of the medial tibial plateau, 1 chondromalacia of the lateral femoral condyle, 1 chondromalacia of the lateral tibial plateau, and 2 chondromalacia of the patella. The location of postarthroscopy ON correlated geographically with pre-existing pathology. All 7 patients had meniscal and/or chondral lesions addressed surgically in the compartment that subsequently developed ON. Six of the 7 patients had an adjacent ipsilateral meniscus tear treated with partial meniscectomy (4 medial, 2 lateral). In addition, of the 4 patients who developed ON of the medial femoral condyle, all had overlying chondromalacia, 3 of whom were treated with arthroscopic chondroplasty. Of the 2 patients with lateral meniscal tears, 1 developed ON of the lateral femoral condyle and the other developed ON of the lateral tibial plateau. Three patients went on to require total knee arthroplasty, and 2 high tibial osteotomy. One patient's ON resolved and another patient was lost to follow-up. CONCLUSION: ON should be considered in patients who have worsening symptoms after arthroscopy of the knee. These findings suggest a possible relationship between arthroscopic treatment of chondral and meniscal lesions and later appearance of ON in some patients. The role of arthroscopy in the development of ON needs to be further studied. Those at risk are elderly patients with chondral and meniscus lesions.

Adult↗

PubMed2000

Effects of stress induced by a simulated shooting on recall by police and citizen witnesses.

Two experiments address the accuracy of citizen and police witnesses in recalling stressful events. Participants saw 2 training scenarios. Experiment 1 evaluated the effects of active engagement and the presence of a simulated shooting on police officers' memory for details. Police officers recalled significantly fewer details from the scenario in which a shooting occurred. Active engagement did not influence recall. Experiment 2 compared the memory performance of police and citizen witnesses. Manipulation checks were added to assess the arousal produced by a shooting, and control procedures were added to evaluate the memorability of specific scenarios. Police and citizen witnesses did not differ reliably in accuracy. The perpetrator was remembered less well than the weapon when a simulated shooting occurred, and one scenario was significantly more difficult to remember than the other. The need to replicate eyewitness research with a variety of materials is discussed.

Adult↗

PubMed1999

CeReS-18 inhibits growth and induces apoptosis in human prostatic cancer cells.

BACKGROUND: Polypeptide growth factors are positive and negative regulators of prostatic growth and function, and many positive regulators of growth in the prostate have been extensively studied. However, very few inhibitors of prostate cell proliferation have been identified. We have isolated a unique 18-kDa sialoglycopeptide (CeReS-18) which inhibits cell proliferation of three separate lines of human prostate cancer cells, as well as inducing cellular cytotoxicity via an apoptotic pathway unrelated to the Bcl-2 family of proteins. METHODS: Cell cycle inhibition was analyzed by direct cell counts with a Coulter (Miami, FL) cell counter. Apoptotic cells were analyzed by electron microscopy, annexin V-fluorescein isothiocyanate (FITC) staining, fluorescence microscopy, and propidium iodide uptake measured with a fluorescence-activated cell sorter. Expression of the proteins of the Bcl-2 family was detected by Western blot analysis. RESULTS: We found that CeReS-18 inhibits cell proliferation of androgen-responsive, LNCaP.FGC human prostate cancer cells, as well as of androgen-nonresponsive DU-145 and PC3 human prostate cancer cells. Furthermore a, fivefold increase over the inhibitory concentration of CeReS-18 elicited a cytotoxic response by all three cell lines. We thus characterized the cytotoxic mechanism as apoptotic in nature, and we measured the expression of several members of the Bcl-2 family in PC3 cells upon treatment with CeReS-18. CONCLUSIONS: The data indicate that CeReS-18 is a potent inhibitor of cellular progression through the cell cycle by both androgen-responsive and androgen-nonresponsive human prostate cancer cells. In addition, treatment of both types of cells with increased concentrations of CeReS-18 induces cellular cytotoxicity, characterized as apoptosis.

Annexin A5↗

PubMed1998

Inhibition of cyclin D-cdk activity in cell cycle arrest of Swiss 3T3 cells by CeReS-18, a novel cell regulatory sialoglycopeptide.

CeReS-18 is a unique negative regulator of cell proliferation with a wide array of target cells. To elucidate the mechanism by which CeReS-18 mediates cell growth inhibition, the possibility that CeReS-18 alters the function of G1 cyclins and their respective cyclin-dependent kinases (cdks) has been examined in mouse fibroblasts (Swiss 3T3) synchronized by CeReS-18. We show here that cyclin D-associated cdk activity is significantly inhibited in the CeReS-18-treated cells. Corresponding to the inhibited cdk function, we demonstrate a low expression of cyclin D in mid G1 determined by Western blot analysis, and cyclin D was greatly reduced in the immunocomplex recovered with antibody to cdk4 and cdk6. Previously, we have shown that the retinoblastoma susceptibility gene product (pRb), a key substrate of cyclin D-cdk complex, was maintained in the hypophosphorylated state in the CeReS-18-inhibited cells. We conclude here that cyclin D/cdk4,6/pRb is the major pathway by which CeReS-18 mediates cell cycle arrest.

3T3 Cells↗

PubMed1998

The influence of advanced age on the outcome of assisted reproduction.

PURPOSE: Our purpose was to determine the influence of age on the outcome of assisted reproduction, with particular interest in women aged 40 years or older. METHODS: A retrospective review of the 779 patients enrolled in the Royal Hospital for Women Fertility Group fertility program between 1987 and 1994 was performed. The results for women aged 40 years or older were compared with those for women between 36 and 39 years and those younger than 36 years. The main outcome measures were pregnancy rate, pregnancy outcome, fertilization rate, and ovarian response. RESULTS: Compared with those in younger women, pregnancy rate, pregnancy outcome, fertilization rate, and ovarian response to controlled ovarian stimulation were significantly worse in women aged 40 years or older. CONCLUSIONS: The outcome of assisted reproduction in women of 40 years of age or older was extremely poor. Compared with those in younger women, pregnancy outcome and ovarian response to controlled ovarian stimulation were significantly worse in women of 40 years or more.

Adult↗

PubMed1997

Cyclic loading of transosseous rotator cuff repairs: tension overload as a possible cause of failure.

Previous experimental studies of failure of rotator cuff repair have involved a single pull to ultimate load. Such an experimental design does not represent the cyclic loading conditions experienced in vivo. We created 1 cm x 2 cm rotator cuff defects in 16 cadaver shoulders, repaired each defect with transosseous simple sutures, and cyclically loaded the repairs by a servohydraulic materials test system actuator at physiologic rates and loads (rate of 33 mm/sec to a load of 180 N.). A progressive gap was noted in each specimen, for a 100% rate of failure of the repairs. A 5 mm gap developed at an average of 25 cycles, and a 10 mm gap developed at an average of 188 cycles. The central suture always failed first and by the largest magnitude. This study suggests that rotator cuff tears that are repaired with a "tension overload" of a portion of the muscle-tendon units will undergo gradual failure with physiologic cyclic loading until the normal resting lengths of the muscle-tendon units are restored. This "controlled failure" of the repairs may explain residual defects that have been demonstrated by ultrasonography and by arthrography in patients with "successful" rotator cuff repairs. Clinical implications are that: 1) rotator cuff tears should be repaired without tension if possible; and 2) transosseous bone tunnels should ideally extend distal to the weak metaphysical bone so that purchase is obtained into cortical bone for greater fixation strength.

Adolescent↗

PubMed1997

CeReS-18, a novel cell surface sialoglycopeptide, induces cell cycle arrest and apoptosis in a calcium-sensitive manner.

Very few growth inhibitors have been identified which can inhibit the proliferation of a broad spectrum of human breast cancer cell lines. CeReS-18, a novel cell surface sialoglycopeptide growth inhibitor, can reversibly inhibit the proliferation of both estrogen receptor positive (MCF-7) and negative (BT-20) human breast cancer cell lines. In addition, at concentrations above those required for the reversible inhibition of cell proliferation, CeReS-18 can also induce cell death in MCF-7 cells. Changes in nuclear and cytoplasmic morphology, characteristic of apoptosis, were detected in MCF-7 cells treated with a cytotoxic concentration of CeReS-18, and internucleosomal DNA cleavage was also observed. The sensitivity of MCF-7 and BT-20 cells to the biological properties of CeReS-18 could be influenced by altering the calcium concentration in the extracellular growth medium, such that when the calcium concentration in the environment was decreased, and increased sensitivity to CeReS-18-induced growth inhibition and cytotoxicity were observed. The addition of the calcium chelating agent EGTA to MCF-7 cells, cultured in a normal calcium environment, could mimic the increased sensitivity to the biological effects of CeReS-18 observed under reduced calcium conditions.

Antineoplastic Agents↗

PubMed1997

Inhibition of hormone and growth factor responsive and resistant human breast cancer cells by CeReS-18, a cell regulatory sialoglycopeptide.

We have previously documented that CeReS-18, a cell regulatory sialoglycopeptide, inhibits the cellular proliferation of normal and transformed cell types from a diverse range of species. Most cell types studies exhibit a similar sensitivity to the reversible but growth inhibitory effects of CeReS-18 at 7 x 10(8) M concentration, while at higher concentrations CeReS-18 can elicit cytotoxicity. The present study was conducted to examine the effect of CeReS-18 on the proliferation of human mammary epithelial carcinoma cells. MCF-7 cells, which are estrogen receptor positive (ER+), and BT-20 cells, which are estrogen receptor negative (ER+), were utilized. Both cell lines show equal sensitivity to growth inhibition elicited by CeReS-18. Complete cessation of cell cycling was achieved with 7 x 10(-8) M CeReS-18, and the arrest was shown to be completely reversible. Flow cytometric analysis, performed on CeReS-18 treated cells from both cell types, revealed that the majority of these cells were arrested in the G1 phase of the cell cycle. When cells were treated simultaneously with inhibitor and stimulatory concentrations of mitogens such as epidermal growth factor (EGF), basic fibroblast growth factor (b-FGF), estrogen, insulin-like growth factors I and II (IGFI and IGFII), no alteration of the inhibitory activity of CeReS-18 was observed. CeReS-18 clearly abrogated the mitogenic activity that these growth factors elicited with human mammary carcinoma cells.

Breast Neoplasms↗

PubMed1997

Physical fitness as a function of psychological and situational factors.

The association between personality variables suggested by Rotter's social learning theory and indices of physical fitness was examined in a sample of U.S. college students. As predicted, both higher value placed on physical fitness and greater internal locus of control were related to selected indicators of physical fitness. In addition, gender of administrator affected performance on certain measures of physical fitness. The results suggest the need for longitudinal studies to evaluate the role of physical activity in mediating the relationship between personality variables and physical fitness.

Adult↗

PubMed1997

Experimental gingivitis in periodontitis-susceptible subjects.

The purpose of this study was to evaluate clinical, microbiological, and gingival crevicular fluid (GCF) profiles in periodontitis-resistant and periodontitis-susceptible subjects during 4 weeks of experimental gingivitis. Experimental groups of similar ages were defined as gingivitis controls (GC; n = 10) and history of rapidly progressive periodontitis (RPP; n = 10), respectively. Prior to baseline, all subjects achieved good plaque control (plaque index (P1I) approximately 0) and gingival health (gingival index (GI) = 0), and had probing depths < or = 4 mm on experimental teeth. For 4 weeks after baseline, oral hygiene around maxillary 2nd premolar and 1st molar teeth was inhibited by a plaque guard. The plaque guard was removed weekly for GCF sampling to determine interleukin (IL)-1 beta and prostaglandin (PG)E2 amounts by ELISAs. In addition, P1I, GI, probing depth, and gingival recession measurements were made. Subgingival plaque darkfield microscopy and DNA probe analysis also were performed. Results indicated that clinical signs of inflammation, microbiological patterns and GCF profiles progressed similarly in both groups. However, plaque accumulated more rapidly in the susceptible subjects. P1I in RPP at 4 weeks was 2.1 +/- 0.1 compared to 1.5 +/- 0.2 in GC, with an incidence of P1I > of 100% versus 50%, respectively (logistic regression; p < 0.0001). Hence, the clinical, microbiological and host factors selected for this study were unrelated to previous susceptibility to periodontitis when evaluated in the experimental gingivitis model. However, the increased rate of plaque accumulation, following thorough plaque removal, in RPP patients suggests a potential factor in disease recurrence in these susceptible subjects.

Adult↗

PubMed1996

Growth inhibition of BALB/c mouse keratinocytes by TGF-beta 1 and CeReS-18 appears to act through distinct mechanisms.

Cell growth is controlled by the complex interactions of both positive and negative growth modulators. Studies were performed to directly compare the growth inhibitory properties of TGF-beta 1 and CeReS-18, a novel cell surface sialoglycopeptide growth inhibitor. Growth inhibition by CeReS-18 and that by TGF-beta 1 shared some similarities although significant differences were apparent. Similarities included a dose-responsive inhibition of BALB/c mouse keratinocyte (MK) cell proliferation that could be nontoxic and reversible. Both CeReS-18 and TGF-beta 1 could equally inhibit the stimulation of DNA synthesis induced by serum or keratinocyte growth factor in MK cells, and in both cases the inhibition was not due to decreased KGF binding to the target cell surface receptor. Inhibition of cell proliferation with CeReS-18, followed by an immediate reincubation with either CeReS-18 or TGF-beta 1, suggested that the sites of arrest mediated by both inhibitors were similar but not necessarily identical. However, recovery from CeReS-18-induced growth inhibition could be achieved by either removing the CeReS-18 or adding calcium directly to CeReS-18-inhibited MK cells, while recovery from TGF-beta 1-induced growth arrest could be reversed only by TGF-beta 1 removal. In addition, the sensitivity of MK cells to CeReS-18-induced cell cycle arrest could be altered by changing the extracellular calcium concentration, but sensitivity to TGF-beta 1 was unaffected by the calcium environment of the MK cells. While recovery from cell cycle arrest was rapid and complete with MK cell cultures inhibited with CeReS-18, removal of TGF-beta 1 led to a slower and incomplete recovery of cell cycling.

Animals↗