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Biomedical subjects

R Carpenter

Publications and source records attributed to R Carpenter.

At least 19 recordsLinked to original sources
PubMed1992

A common gene regulates pigmentation pattern in diverse plant species.

The delila (del) gene regulates the pattern of red anthocyanin pigmentation in Antirrhinum majus plants. We describe the cloning of the del locus by transposon tagging and show that it encodes a protein with extensive homology to products of the R gene family, which regulates pigmentation in maize. This shows that in spite of the many differences in morphology and coloration between maize and Antirrhinum, the control of pigmentation pattern is mediated by a common regulator. The del and R products contain a region similar to the conserved domain of the helix-loop-helix family of transcription factors. In situ hybridization and RNA analysis show that the expression of del correlates with the distribution of anthocyanins in the flowers. We discuss the implications of these findings for the evolution of regulatory networks.

Amino Acid Sequence↗
PubMed1992

Demonstration of interleukin 6 in middle ear effusions.

In response to infection in the middle ear, inflammatory cells produce cytokines--potent regulators and mediators of the immune response. In an earlier study, we demonstrated that levels of the cytokine interleukin 1 were higher in middle-ear effusions from younger children, while levels of the cytokine tumor necrosis factor were higher in middle-ear effusions from older children and in those requiring tympanostomy on multiple occasions. In this study, we evaluated middle-ear effusions for levels of the cytokine interleukin 6. Activities of interleukin 6 include stimulation of bone erosion and production of antibodies and fever. Using an enzyme-linked immunosorbent assay system, significant levels of interleukin 6 (greater than 0.2 pg/mL) were found in 14 (36%) of 39 middle-ear effusions from 25 children with otitis media with effusion. The mean (+/- SE) level of interleukin 6 in middle-ear effusions was 173.9 +/- 74.7 pg/mg of total protein. Like interleukin 1, levels of interleukin 6 were higher in younger children. Tumor necrosis factor may be an important regulator of the local immune response in the middle-ear cleft during persistence of otitis media with effusion, while interleukin 1 and interleukin 6 may be important regulators during the early stages of otitis media with effusion.

Child, Preschool↗
PubMed1992

Continuing experience with transaxillary excision of the first rib for thoracic outlet syndrome.

The results of transaxillary excision of the first rib for thoracic outlet syndrome are reported. During a 3-year period, 40 transaxillary rib resections were performed on 32 patients. The symptoms in 33 limbs were completely relieved and in a further four symptoms were improved. These results confirm that transaxillary excision of the first rib is the operation of choice in the management of thoracic outlet syndrome.

Adolescent↗
PubMed1992

Eye movement desensitization versus image confrontation: a single-session crossover study of 58 phobic subjects.

Eye movement desensitization (EMD) and a control procedure, image confrontation (IC) were compared in a group of 58 phobics, 31 of them arachnophobes. Subjects confronted disturbing images in a single-session crossover trial. Anxiety levels were recorded on the SUD Scale. Whenever practicable, SUDs to feared objects were also recorded. EMD and IC were equally effective in reducing anxiety levels. After 1 month, during which subjects were encouraged to use IC daily, improvement was maintained. Since exposure to the disturbing image is common to both methods it must be presumed to be the basis of change when EMD is used in cases of phobia.

Adult↗
PubMed1992

Loco-regional recurrence and survival after wide local excision, radiotherapy and axillary clearance for early breast cancer.

After breast conservation for early breast cancer which comprised wide local excision, axillary clearance and radiotherapy to the breast, 145 women have been followed prospectively for a median of 42 months. Local recurrence occurred in 11 (7%) and axillary recurrence in three (2%). Distant recurrence has occurred in 32 and accounted for 80% of all first recurrences. Local treatment failure has occurred in three women and would not have been prevented by mastectomy. Loco-regional recurrence in the absence of preceding or synchronous distant disease was unusual and did not pose a significant clinical problem.

Adult↗
PubMed1992

Colo-mucosal proctectomy with ileo-anal anastomosis. The Jamaican experience.

A total colectomy and a mucosal proctectomy with ileo-anal anastomosis (c-mp-iaa) effectively removes all debilitating, potentially malignant colonic mucosa. Preservation of the anorectal sphincter predictably results in good to excellent anal continence with a low mortality and acceptable morbidity. Since 1983 at the University Hospital of the West Indies (U.H.W.I.), Jamaica, five (5) patients have undergone c-mp-iaa for colonic mucosal disease. All have good to excellent anal continence with an average of 2-6 continent, formed stools per day. There were no operative deaths. The five (5) cases are described and a plea is made for the earlier use of this definitive surgical procedure where indicated.

Adolescent↗
PubMed1992

Effect of macronutrient composition of an energy-restrictive diet on maximal physical performance.

Thirty-six sedentary, mildly obese (30-40% fat), premenopausal women (29-49 yr) were randomly assigned to one of two dietary regimens for an 8-wk double-blind, parallel study of the effect of moderate caloric restriction and macronutrient variation on maximal physical performance. Group 1 (N = 19) consumed 4186 kJ.d-1 (1000 kcal.d-1) with a diet composition of 40% fat, 40% carbohydrate (CHO), and 20% protein. Group 2 (N = 17) also consumed 4186 kJ.d-1 but varied the percent kilojoules to 20% fat, 60% CHO, and 20% protein. Maximal aerobic power was measured using a modified Balke protocol, strength was assessed using isotonic bench and leg press machines and a Cybex 340 isokinetic device during knee flexion and extension, and muscular endurance was taken as the number of sit-ups performed in 1 min. Pre- to post-testing revealed significant (P less than or equal to 0.05) reductions in body weight (group 1, -7.4 kg; group 2, -6.5 kg) within both groups. No significant changes were seen in maximal aerobic power within both groups. Strength measures for both groups showed a trend toward reduction but statistical significance was only evident in right knee extension for group 1 and left knee extension for group 2 (P less than or equal to 0.05). Sit-up number increased nonsignificantly for both groups. Between group differences were not found in any body weight, body composition, or physical performance index. We therefore conclude that in mildly obese women, maximal exercise performance is relatively unimpaired after 8 wk of caloric restriction with either of two diets differing moderately in their macronutrient content.

Adult↗
PubMed1991

Localization of type X collagen in canine growth plate and adult canine articular cartilage.

Type X collagen was extracted from ends of canine growth plates by pepsin digestion after 4 M guanidine hydrochloride extraction, purified by stepwise salt precipitation (2.0 M NaCl in 0.5 M acetic acid), and chromatographed on a Bio-Gel A1.5 M column in 1.0 M CaCl2. Without reduction on sodium dodecyl sulfate (SDS) polyacrylamide gels, the preparation yielded a single, high-molecular-weight (mol wt) band; after reduction, a single band of relative mol wt 5.0 x 10(4) was found. Polyclonal sera were raised against the purified collagen and used in the immunolocalization of canine type X collagen. As expected, indirect immunoperoxidase (IP) or indirect immunofluorescent staining with the polyclonal sera demonstrated that most of the immunoreactivity was localized in the zone of provisional calcification of the growth plate and in cartilage remnants in the metaphyseal region of the physis. A progressive decrease in staining toward the diaphysis of the fetal canine long bone was apparent as the trabecular structures were remodeled to bone. Unexpectedly, type X collagen was also detected in the zone of calcified, mature articular cartilage. It was concentrated in the pericellular matrix of the chondrocytes, appeared at or just above the tidemark, and was expressed immediately before mineralization. Identification of type X collagen in both the canine growth plate and the zone of calcified articular cartilage suggests that cells in the deep layer of cartilage and in the zone of calcified cartilage in the adult animal retain some characteristics of a growth plate and may be involved in regulation of mineralization at this critical interface. The expression of growth plate-like properties would allow the deep chondrocytes of mature articular cartilage to play a role in remodeling of the joint with age and in the pathogenesis of osteoarthritis.

Animals↗
PubMed1991

The stereospecific determination of fluoxetine and norfluoxetine enantiomers in human plasma by high-pressure liquid chromatography (HPLC) with fluorescence detection.

A quantitative method for the simultaneous HPLC resolution and detection of the enantiomers of (R,S) fluoxetine (F) and their metabolites (R,S) norfluoxetine (N) in human plasma has been developed. F is a serotonin uptake inhibitor used in the treatment of depression and is administered as a racemate. After liquid-liquid extraction and derivatization with (R) napthyl ethyl isocyanate (NEI), the separation and detection of the resultant diasteriomers were achieved using normal phase HPLC and fluorescence. The four NEI diastereomers and the internal standard [(-)-N-methyl-gamma-(2-methylphenoxy) benzenepropanamine hydrochloride], representing the enantiomers S-F, R-F, S-N, and R-N were resolved within 15 min. The assay for each analyte was linear using two concentration ranges of 1-10 and 10-500 ng/ml of human plasma. The precision and accuracy are reported as the coefficient of variation (%CV) and relative error (%RE). The sum of the chiral HPLC results from plasma samples were compared to the achiral gas chromatographic/electron capture (GC/EC) results. The correlation between these two methods, for total F and N, resulted in r2 values of 0.98 and 0.89, respectively. The chiral HPLC method is currently being applied to clinical studies for the evaluation of the enantiomeric disposition of F.

Antidepressive Agents, Tricyclic↗
PubMed1991

Allelic interactions at the nivea locus of Antirrhinum.

Most null alleles at the nivea (niv) locus are recessive to Niv+ and, when homozygous, give white flowers rather than the red of the wild type. In contrast, the niv-571 allele is semidominant; although it gives white flowers when homozygous, very pale flowers result when this allele is heterozygous with NIV+. We showed that in heterozygotes, niv-571 acts in trans to inhibit expression of its Niv+ homology 25-fold to 50-fold. The inhibition is reversible after meiosis and partially reversible somatically. The niv-571 allele carries a transposable element Tam3 insertion and three truncated copies of the niv gene, one copy being in inverse orientation. Analysis of two further niv alleles, niv-572 and niv-527, showed that excision of Tam3 from niv-571 does not affect the ability of the allele to repress Niv+ and that one truncated niv copy alone is insufficient to confer semidominance. The detailed structures of various semidominant niv alleles suggest that their effects in trans are not readily explained by production of antisense RNA but are more easily reconciled with a direct recognition/interaction between homologous genes, reminiscent of cosuppression and transvection phenomena described in other systems.

Acyltransferases↗
PubMed1991

The effect of a single breath of 100% oxygen on breathing in infants at 1, 2, and 3 months of age.

Sequential measurements of the ventilatory response to a single breath of oxygen delivered during quiet sleep were made in 16 healthy infants between 1 and 3 months of age, alternately breathing air and 16% oxygen in nitrogen. At 1 month the response to a single breath of oxygen during normoxia was a decrease in minute ventilation of 264 +/- 34.2 (SEM) ml.min-1 during the 10-s period following the stimulus (p less than 0.001). During mild hypoxia the decrease in ventilation averaged 471 +/- 49.1 (SEM) ml.min-1 (p less than 0.001). The difference in response between measurements in air and mild hypoxia was significant (p less than 0.001). By the age of 3 months, the absolute ventilatory response to a single breath of oxygen increased significantly in normoxia by 118 +/- 35.2 ml.min-1 (p less than 0.01); the test response to breathing 16% oxygen paralleled the response to normoxia and was on average 254 +/- 26.6 ml.min-1 larger than the response when breathing air (p less than 0.001). When the three age groups were compared, calculating the response per killigram body weight showed that the response was similar at all three ages tested. These data provide a reference baseline for normal infants.

Chemoreceptor Cells↗
PubMed1991

Impact of an extensive in situ component on the presence of residual disease in screen detected breast cancer.

This study investigates the histopathological characteristics of a consecutive series of 100 screen detected breast cancers in relation to residual disease. Tumour type, size, grade, resection margins and extent of primary or associated in situ disease were all assessed by one pathologist. Thirty-seven women underwent further surgery (wider excision or mastectomy) and the resected specimen was examined for residual in situ or invasive cancer. In total, 36 cancers had an extensive in situ component, of which 69% were predominantly intraduct carcinoma of comedo type. Of the 37 women who underwent further resection, 21 (57%) women had residual cancer. Of those with initial disease at the resection margin, 16/25 (64%) had residual disease. Five of 12 (42%) with disease close to (within 2-3 mm) but not at the margin had residual disease. Of those with an extensive in situ component, 18/25 (72%) had residual disease, whereas only 2/12 (17%) women with none or some in situ disease had residual cancer. In screen detected breast cancer, residual cancer was present in 72% of women with an extensive in situ component at initial surgery. These women comprise a group in which conservation surgery may be inappropriate if completeness of excision is considered a prerequisite for breast conserving surgery.

Breast Neoplasms↗
PubMed1991

Pigmentation mutants produced by transposon mutagenesis in Antirrhinum majus.

New pigmentation mutants were generated by transposon mutagenesis in Antirrhinum majus, in three previously described loci, nivea, delila and incolorata, and two new loci, daphne and olive. The wild-type olive gene is required for the production of dark-green leaves, and the daphne gene for the synthesis of flavones. Five out of the six mutants were both germinally and somatically unstable, indicating that they resulted from transposon insertions. Molecular analysis of the mutant at nivea (niv-600) showed that it was caused by insertion of a new transposon, Tam4. The sequence of Tam4 suggests that it is unable to transpose autonomously and that it is related to Tam1 and Tam2. All three of these transposons have identical inverted repeats, produce 3 bp target duplications, leave similar excision footprints and share at one end a 600-700 bp region containing many palindromic copies of a motif sequence, possibly required in cis for transposition. The somatic excision of Tam4 in niv-600 is at a very low rate compared to germinal excision but it can be activated by crossing to lines carrying derivative alleles of a Tam1 insertion at niv. Molecular analysis of four different pigmentation mutants has shown that insertions of Tam1, Tam2, Tam3 and Tam4 have been obtained, illustrating the potential of general transposon mutagenesis for trapping and isolating new transposons as well as for tagging genes.

Base Sequence↗
PubMed1991

ERICA predicts response to tamoxifen in elderly women with breast cancer.

Oestrogen receptor status has been determined by an immunocytochemical assay using fine-needle aspiration samples of primary breast cancers in elderly patients. In a prospective study 56 patients were treated with tamoxifen only. Satisfactory assays were achieved in 49 patients. Disease was controlled by tamoxifen in 32 of 35 (91%) patients with oestrogen receptor positive tumours, compared with only 1 (7%) of 14 who were receptor negative. Immunocytochemical assay on fine-needle aspiration samples is relatively non-invasive and simple to perform, it accurately predicts response to tamoxifen in elderly patients and can be used to select patients for tamoxifen only therapy.

Aged↗
PubMed1991

Use of the OM-11-906 monoclonal antibody for determining p62 c-myc expression by flow cytometry in relation to prognosis in colorectal cancer.

The expression of the c-myc protein product (p62 c-myc) and deoxyribonucleic acid (DNA) ploidy status was determined by a flow cytometric technique in 83 patients with colorectal cancer followed up for a median of 30 months (range 6-60 months). The OM-11-906 antibody, used to detect p62 c-myc, revealed a 62 kDa and 45 kDa band on Western blots in tumours. Correlation of quantitative dot blotting of tumour mRNA to flow cytometric p62 c-myc expression was good (r = 0.87, P less than 0.01). Levels of p62 c-myc varied in colorectal cancer and low levels (less than 20 fluorescein units) correlated with improved survival (log rank chi 2 = 4.69, df = 1, P = 0.03), and this was a better prognostic index than DNA ploidy (log rank analysis chi 2 = 2.38, df = 1, P less than 0.1). Although expression of the c-myc gene was found, using the OM-11-906 antibody, to be a prognostic feature in colorectal cancer, these and other results need to be interpreted with caution given the presence of two protein bands by Western blotting.

Adult↗
PubMed1991

Monocyte-derived giant cell formation in patients with breast cancer.

Recent reports of monocyte-derived giant cell formation in breast cancer and associated retroviral findings have attracted much interest in the scientific literature and with the media, revitalising hypotheses of a viral role in the aetiology of the disease. We describe an assay developed to investigate further the giant cell forming phenomenon and report results which conflict with earlier work. We observed a smaller proportion of patients with breast cancer forming giant cells than in previous reports. Conversely, a much larger proportion of controls formed giant cells. Using our assay to calculate a fusion index the formation of giant cells, as defined in earlier work, was found to be a poor indicator of the degree of cell fusion in our samples. We discuss our experiences with the assay and suggest the calculation of a fusion index as a more comparable and quantitative measurement of cell fusion.

Adolescent↗