PubMed Health⌕ Search

Biomedical subjects

C Gates

Publications and source records attributed to C Gates.

At least 19 recordsLinked to original sources
PubMed2000

Clonal isolation of muscle-derived cells capable of enhancing muscle regeneration and bone healing.

Several recent studies suggest the isolation of stem cells in skeletal muscle, but the functional properties of these muscle-derived stem cells is still unclear. In the present study, we report the purification of muscle-derived stem cells from the mdx mouse, an animal model for Duchenne muscular dystrophy. We show that enrichment of desmin(+) cells using the preplate technique from mouse primary muscle cell culture also enriches a cell population expressing CD34 and Bcl-2. The CD34(+) cells and Bcl-2(+) cells were found to reside within the basal lamina, where satellite cells are normally found. Clonal isolation and characterization from this CD34(+)Bcl-2(+) enriched population yielded a putative muscle-derived stem cell, mc13, that is capable of differentiating into both myogenic and osteogenic lineage in vitro and in vivo. The mc13 cells are c-kit and CD45 negative and express: desmin, c-met and MNF, three markers expressed in early myogenic progenitors; Flk-1, a mouse homologue of KDR recently identified in humans as a key marker in hematopoietic cells with stem cell-like characteristics; and Sca-1, a marker for both skeletal muscle and hematopoietic stem cells. Intramuscular, and more importantly, intravenous injection of mc13 cells result in muscle regeneration and partial restoration of dystrophin in mdx mice. Transplantation of mc13 cells engineered to secrete osteogenic protein differentiate in osteogenic lineage and accelerate healing of a skull defect in SCID mice. Taken together, these results suggest the isolation of a population of muscle-derived stem cells capable of improving both muscle regeneration and bone healing.

Alkaline Phosphatase↗
PubMed2000

Experience with the insertion of vena caval filters in acutely burned patients.

The use of inferior vena caval filters in patients at high risk of pulmonary emboli is a standard practice in many types of patients. The usefulness of such filters in acutely burned patients has yet to be established. Twenty inferior vena caval filters were inserted in burn patients. Five were inserted because of preexisting thromboembolic disease. Fifteen were placed prophylactically because of high-risk states, including prolonged immobilization, old age, bleeding problems, and obesity. There were no complications due to filter insertion. No postinsertion emboli were recognized. There were no cases of postinsertion thrombophlebitis. In this small series, the procedure appears to be effective and safe.

Acute Disease↗
PubMed1998

How a computer-based training module for the marine medic was developed.

This article is a discussion of how a prototype Computer-based Training (CBT) program module was developed by a team of people representing different nationalities and from various professions including nursing, engineering, and medical graphics. Multimedia solutions that would facilitate the training of Marine corpsmen to perform their mission as first responder in combat incidents were examined. Three separate software models were evaluated. The prototype chosen was selected because of its simplicity, user-friendliness, and cost effectiveness.

Computer-Assisted Instruction↗
PubMed1993

LY207320 (6-methylene-4-pregnene-3,20-dione) inhibits testosterone biosynthesis, androgen uptake, 5 alpha-reductase, and produces prostatic regression in male rats.

LY207320 is an in vitro inhibitor (estimated IC50 = 0.06 microM) of steroid 5 alpha-reductase that catalyzes the conversion of testosterone (T) to dihydrotestosterone (DHT). In contrast, LY207320 was only moderately active against rat prostatic 5 alpha-reductase in vivo (32% inhibition at 50.0 mg/kg single dose). LY207320 did, however, inhibit the in vivo uptake of [3H]-T by the prostate. The antiprostatic and endocrine effects of this agent were evaluated following daily (21 days) administration to castrated, androgen-supplemented castrate, and intact rats. LY207320, which has modest progestational competitive binding activity, does not bind to rat prostatic androgen or uterine estrogen cytosolic receptors. In the castrated male rat, subcutaneously (s.c.) administered LY207320 had no androgen agonist activity, as evidenced by a lack of accessory sex organ weight gains. Administration of s.c. LY207320 to intact rats for 21 days at doses greater than 5.0 mg/kg-day produced significant (P < 0.05) reductions of seminal vesicle and ventral prostatic weights (maximal regression = -65% and -40% from control values, respectively at 50.0 mg/kg-day). The compound had no regressive activity on male accessory sex organs when administered orally. LY207320 did not alter circulating prolactin, LH, or corticosterone levels, but at high doses (> or = 50.0 mg/kg-day), lowered circulating T[-67% from intact control levels (P < 0.05)]. Histological analysis of the rat ventral prostates (RVPs) in LY207320-treated rats was consistent with an androgen-deprived state. Decreased circulating androgens and prostatic regression are associated with inhibition of testicular 17 alpha-hydroxy/C17,20-lyase enzyme activity (IC50 = 0.06 microM). These findings support the contention that LY207320 is a physiological antagonist of androgen action in male rats, and that its effects are mediated primarily through inhibition of testicular androgen production rather than accessory sex organ 5 alpha-reductase.

Aldehyde-Lyases↗
PubMed1993

Critical role of peripheral blood phagocytes and the involvement of complement in tumour necrosis factor enhancement of passive collagen-arthritis.

Studies have implicated tumour necrosis factor-alpha (TNF-alpha) in type-II collagen (CII)-induced arthritis (CIA), a well established animal model of human rheumatoid arthritis. Precisely how TNF is involved in CIA is not yet clear. In this study the effects of TNF on CIA were examined, independent of its potential effects on the immune response, by performing peri-articular injection of TNF in combination with passive immunization of rats. A sub-arthritic dose (5 mg) of affinity-purified anti-CII IgG, which alone was insufficient to induce spontaneous clinical arthritis, was used throughout the study. Obvious clinical arthritis that persisted for several days was rapidly induced by injections of 100 ng TNF into hindpaws of rats that were passively immunized shortly before the TNF injection. Injections of TNF in non-immunized control rats did not induce clinical arthritis, nor did buffer-only injections in passively immunized controls. The clinical arthritic response was a local phenomenon, limited only to the TNF-injected hindpaws. No swelling was observed in the opposite, buffer-injected hindpaws, indicating the effects of TNF were not systemic. Depletion of peripheral blood phagocytes with anti-rat neutrophil antiserum before passive immunization completely abolished the ability of TNF to induce clinical arthritis, identifying phagocytic cells as the essential target cells in evoking this arthritic response. A role for complement activation was also demonstrated in this model through the use of a soluble recombinant version of CD35, the cell surface complement receptor type-1 (sCR1, BRL55730), which significantly reduced TNF-induced arthritis in phagocyte-replete rats.

Animals↗
PubMed1993

Amphotericin B and its delivery by liposomal and lipid formulations.

In recent years, new formulations of the original amphotericin B preparation (Fungizone) have been devised in order to overcome toxicity problems that frequently occur. These preparations represent an improved method of drug delivery, with an increased therapeutic index and a decrease in toxicity to mammalian cell membranes. The new formulations have different physico-chemical characteristics and differ in pharmacokinetic parameters. Their effects must be compared with conventional amphotericin B to ascertain potential roles in future antifungal therapy.

Amphotericin B↗
PubMed1993

Systemic Pasteurella haemolytica infection as a rare sequel to avirulent live Pasteurella haemolytica vaccination in cattle.

Eleven cases of systemic Pasteurella haemolytica infection in cattle were identified from routine diagnostic laboratory submissions during the falls of 1988, 1989, and 1991. All cases came with a history of recent vaccination with an avirulent live culture P. haemolytica product. Nine of 11 cases involved cattle vaccinated between 2 and 18 days previously with this product. Ten of 11 cases involved 182-227-kg beef calves that were vaccinated between September and November during routine processing for entry into feedlots. The morbidity and mortality was generally low. The major pathologic findings included meningitis, injection site abscessation and/or cellulitis, and polyarthritis. Systemic infection was indicated in all cases by the isolation of P. haemolytica from 2 or more organs or distinct anatomical sites. In 6 cases, the vaccine injection site was cultured, and in all 6 cases, P. haemolytica was isolated. Three separate P. haemolytica isolates from 2 cases were further studied by restriction enzyme analysis (REA). These isolates were from tissues with suppurative inflammation, including the brain, joint, and injection site. The REA patterns of each of these 3 isolates were identical to the REA pattern of the vaccine masterseed, which strongly suggested that the organisms causing systemic infection were the same as the organism used to produce the vaccine. Because the overall incidence was quite low, other factors, such as stress, probably played a major role in the expression of this syndrome.

Animals↗
PubMed1991

Diagnosis of pregnancy in wood bison using a bovine assay for pregnancy-specific protein B.

Blood samples were collected from 51 wood bison (Bison bison athabascae ) and evaluated for the presence of an antigen that cross-reacted with antisera to pregnancy-specific protein B(PSPB). The objective of this study was to determine if the PSPB radioimmunoassay (RIA) was a reliable indicator of pregnancy in these animals. Pregnancy of mature females was determined either at autopsy (20 animals) or by palpation per rectum after chemical immobilization (18 animals). The antigen was not detected in either males or juvenile females. There was minor cross-reaction in sera of one of nine nonpregnant females that had been exposed to males. The antigen was found in the sera of 25 of 27 females that were confirmed pregnant. It was concluded that the PSPB RIA was a useful tool in the determination of pregnancy in wood bison.

Journal Article↗
PubMed1988

Plasma components are required for platelet activation by the toxin of Loxosceles reclusa.

We have used a partially purified toxin from the venom of the brown recluse spider, Loxosceles reclusa, to study its effects on human platelets isolated from plasma proteins. This toxin, which produced skin necrosis in rabbits, contained sphingomyelinase D activity. The toxin induced platelet aggregation and secretion of [3H]serotonin in human plasma but not in buffer or in human neonate plasma. Ca2+ was required for the interaction of toxin, platelets, and plasma factor(s). The addition of C-reactive protein restored aggregation and serotonin release of platelets incubated in human neonate plasma. The ADP-degrading enzyme, apyrase, and the non-steroidal, anti-inflammatory drug, indomethacin, inhibited platelet aggregation, suggesting that ADP secreted from platelet storage granules and indomethacin-sensitive pathway(s) are involve in the toxin-induced human platelet activation (aggregation and serotonin release). Generation of platelet activating factor (PAF) from the platelet by brown recluse toxin is not likely since the PAF receptor antagonist, BN 52021, did not inhibit platelet aggregation induced by the brown recluse toxin.

Adenosine Diphosphate↗
PubMed1986

Suicide among schizophrenics: a comparison of attempters and completed suicides.

Schizophrenics who completed suicide were compared with those who made suicide attempts, on the basis of blind ratings of previous hospital records and follow-up interviews with treating clinicians. Results indicated that the two groups were relatively distinct. Suicides tended to live alone and to feel depressed, hopeless, worthless, and suicidal. Attempters, on the other hand, lived with their families or others and were less likely to manifest several features of depression during a period in hospital. In evaluating suicide potential among schizophrenics, living situation and mental state changes indicating depression, suicidal intent, worthlessness, and hopelessness are more important than a history of suicidal behaviour.

Female↗
PubMed1984

Suicide among schizophrenics. Who is at risk?

Schizophrenic patients are at high risk for suicide. Most of the clinical features of the illness which have been associated with suicide remain speculative. This study provides an empirical test of hypothetical risk factors from the literature. Results indicate that schizophrenic patients who kill themselves have high internalized standards of performance which are often congruent with past educational attainments. They are also realistically aware of the effects of their illness, feel inadequate in relation to their goals, and fear further mental disintegration. Their affect is depressed, and they express hopelessness about the future. Suicidal ideation and explicit suicide threats often precede death. These results can be used to assess suicide risk among schizophrenic patients.

Adult↗
PubMed1983

Well-being of cancer survivors.

One hundred and four cancer survivors 3 years past their last cancer treatment reported a significantly lower sense of self-control and more general health worries than a matched sample of healthy controls. The two groups did not differ on variables of anxiety, depression, positive well being, and vitality or on two composite scores of mental and general well-being. The well-being scores of the survivors from three geographically distinct cancer centers revealed no significant differences among centers on the composite or any of the individual subscores. Sociodemographic and treatment variables revealed only marriage and no change in job were significantly related to the amount of general well-being experienced.

Adult↗
PubMed1983

Lack of virus-specific bacterial adherence to bovine embryonic lung cells infected with bovine parainfluenza virus type 3.

Infection of bovine embryonic lung cells with bovine parainfluenza virus type 3 did not induce in vitro, virus-specific, hemadsorption-related adherence of Corynebacterium pyogenes, Haemophilus somnus, Staphylococcus aureus, Streptococcus zooepidemicus, Pasteurella haemolytica, Listeria monocytogenes, Escherichia coli, Pasteurella multocida, Brucella sp., or Salmonella typhimurium.

Adhesiveness↗
PubMed1981

Development of brief measures of psychological adjustment to medical illness applied to cancer patients.

The interrater reliability and validity of brief interview rated measures of psychosocial adjustment were examined in four sequential studies. A total of 25 videotaped interviews with cancer patients were rated by 105 social workers, nurses, physicians, and specialists in psychosocial oncology. The Rating of Psychosocial Function (RPF), Coping Adequacy Rating (CAR), and Global Adjustment to Illness Scale (GAIS) were used by various rating groups with an indication of interrater agreement. Agreement on ratings was not influenced by the length of interview (15 vs. 30 minutes) but appeared to the affected by the structure of the interview and profession of the raters. All three instruments showed a measure of matching with clinical impressions in addition to demonstrating a measure of both convergent and divergent construct validation. The GAIS was chosen as most adequately reflecting their clinical impression by a majority of raters. With a degree of training, any of the three instruments could be used to assess psychosocial adjustment with some measure of confidence in the validity of the rating.

Adaptation, Psychological↗
PubMed1981

Porcine abortions associated with Fungi, Actinomycetes, and Rhodococcus sp.

History, lesions, and results of microbiologic examinations are given for four porcine abortions associated with fungi and one each associated with Actinomadura madurae, an aerobic actinomycete, and Rhodococcus sp. The fungi were Gliomastix sp., Petriellidium boydii, Aspergillus fumigatus, and Exophiala jeanselmei. Parvovirus, isolated from one fetus, was the only other infectious agent identified. The presence of fungi, Actinomadura madurae, and Rhodococcus sp. in fetal and placental lesions indicates that they are a primary cause of sporadic abortion in pigs.

Abortion, Veterinary↗
PubMed1979

A survey of psychotropic drug prescriptions in an oncology population.

The present study examined the prescription practices concerning psychotropic drugs in 5 major oncology centers over a 6 month period. During the survey period 1579 patients were admitted to the collaborating institutions, and 51% of them were prescribed at least one psychotropic medication. Hypnotics were the most frequently prescribed drugs, accounting for 48% of total prescriptions, followed by anti-psychotics at 26% and anti-anxiety agents at 25%. Anti-depressant drugs accounted for only 1% of psychotropic prescriptions. Analysis of prescription rationales revealed that 44% of the psychotropic prescriptions were written for sleep, while 25% were given for nausea and vomiting; approximately 17% were attributed to psychological distress, and 12% were associated with diagnostic medical procedures. The overall rate of prescription was approximately 2 psychotropic drugs per patient per admission, with only 2% of prescriptions resulting in chart-documented side effects. At the level of individual compounds, 3 distinct drugs accounted for 72% of total prescriptions--flurazepam (33%), prochlorperazine (21%), and diazepam (17%).

Anti-Anxiety Agents↗