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Biomedical subjects

R Carpenter

Publications and source records attributed to R Carpenter.

At least 109 records · Page 6Linked to original sources
PubMed1995

Primary aortoenteric fistula.

One hundred and thirty-eight patients with abdominal aortic aneurysms were treated by aneurysmorrhaphy over an eleven-year period. Six patients, all male and aged 60-74 years, were found to have developed primary aortoenteric fistulae. Four patients presented with bleeding into the gastrointestinal tract in association with a tender abdominal swelling. In the other two cases, the aneurysm was discovered at emergency laparotomy for gastrointestinal haemorrhage. The presence of the fistula was confirmed at operation in five patients and at autopsy in one. Two patients died, one from a massive gastrointestinal haemorrhage prior to surgery, the other from sepsis complicated by Adult Respiratory Distress Syndrome and renal failure following operation.

Aged↗
PubMed1994

Fimbriata controls flower development by mediating between meristem and organ identity genes.

Two major classes of genes directing flower development have so far been described: early activated genes regulating meristem identity and later acting genes controlling organ identity. Here, we show that the fimbriata (fim) gene acts between these two classes in a sequence of gene activation. The fim gene, originally described in 1930, was cloned by transposon tagging from Antirrhinum majus and encodes a product with no detectable homology to other proteins. Mutations in fim result in partial homeotic transformations of floral organs and in reduced determinacy of the meristem. Expression and function of fim depends on the activity of meristem identity genes, and fim in turn controls the spatial and temporal expression of organ identity genes. The pattern of fim expression defines a new domain of the floral meristem that changes with time in a complementary manner to those of the meristem identity gene floricaula and the organ identity gene plena.

Amino Acid Sequence↗
PubMed1994

Interleukin-8 expression in otitis media.

Based on recent studies in the authors' laboratory on the correlation of cytokines and inflammation in otitis media (OM), the authors hypothesized that in chronic otitis media with effusion (COME) interleukin-8 (IL-8) is responsible for 1. the accumulation of leukocytes in the middle ear cleft and 2. in situ leukocyte activation with subsequent tissue damage. Additionally, the authors hypothesized that IL-8 expression is at least in part under the control of interleukin-1 (IL-1) and tumor necrosis factor (TNF). To begin to test this hypothesis, middle ear effusions (MEE) obtained from children ages 2 to 90 months (mean age, 29 months) undergoing tympanostomy tube placement for the presence of these inflammatory cytokines were analyzed. For these studies, IL-8, interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), and tumor necrosis factor-beta (TNF-beta) were measured in MEE by radioimmunoassay (RIA) or enzyme-linked immunoassay (ELISA). IL-8, IL-1 beta, TNF-alpha, and TNF-beta were present in 92%, 67%, 77%, and 0% of effusions, respectively. The mean (+/- SEM) values for IL-8, IL-1 beta, and TNF-alpha were 4805 (+/- 913) pg/mg, 4076 (+/- 1510) pg/mg, and 163 (+/- 90) pg/mg. Further analysis indicated that levels of IL-8 correlated with IL-1 beta (R2 = .500, P = .000) and TNF-alpha (R2 = .387, P = .023). Thus the authors' studies clearly demonstrate that IL-8 is consistently present in the MEE of children with COME and is strongly correlated with levels of IL-1 beta and TNF-alpha, both known inducers of IL-8 production. These results support the authors' hypothesis that IL-1 beta, TNF-alpha, and IL-8 are intimately involved in the inflammatory cascade in the middle ear and suggest regulation of these cytokines as possible sites of future therapeutic intervention in otitis media with effusion (OME).

Age Factors↗
PubMed1994

Prognosis of neuroblastic tumours in children.

A retrospective analysis of 26 children with neuroblastic tumours treated at the University Hospital of the West Indies (UHWI) between 1970 and 1991 was undertaken to evaluate factors affecting prognosis. The peak incidence was between 48 months and 60 months of age, and 75% of the deaths occurred in children older than 3 years. The abdomen was the most common site of the tumours 79% of which were from the adrenal gland and carried a dismal outcome. Other sites were thoracic, pelvic and cervical. Extra-adrenal tumours have a good outcome even when the histology is unfavourable; 92% of the tumours were in Stages III or IV at the time of initial presentation. Stage IV disease accounted for all but one of the deaths. Of the 8 children with favourable histology (ganglioneuroma or well-differentiated ganglioneuroblastoma), only one (12.5%) died, wheras of the remaining 18 cases with unfavourable histology (neuroblastoma and undifferentiated ganglioneuroblastoma), eleven (61.1%) died. When managed by surgery alone or with adjuvant chemo- and/or radio-therapy, only 36.4% succumbed while all 4 children with chemotherapy only died. Ten children are alive without disease for more than three years post-therapy. A scoring system was designed which takes into account the factors influencing the outcome in neuroblastic tumours, namely, age, location, stage and histological types of the tumours and therapy. All the children with a score of 21 or less survived, whereas all those with scores of 22 or above succumbed. This underlines the multifactorial influences on the final outcome of neuroblastic tumours.

Abdominal Neoplasms↗
PubMed1994

Admissions for trauma at the University Hospital of the West Indies. A prospective study.

Trauma accounted for 20% of all admissions to the general surgery wards of this University Hospital in a developing country. It was the most common reason for admission. This condition affects the young, males more commonly than females, and results in the need for operation in almost 40% of admitted trauma patients. Trauma surgery accounts for 17% of all operations done. Hospital stay and age are significantly greater in those requiring operation. The head, chest and abdomen are, in order of frequency, the most commonly affected areas of the body, and injury is mainly the result of interpersonal violence (52%), accidental injuries including burns (20%), and road traffic accidents (20%). In-patient mortality was 4.5%, significantly higher in older patients and mainly in those with head injuries and burns. Scarce resources and resource misallocation mandate preventive measures to minimize the human and economic waste.

Adolescent↗
PubMed1994

Outcome of solid renal tumours in children at the University Hospital of the West Indies.

Of the twenty-nine children with solid renal tumours treated at the University Hospital of the West Indies (UHWI) between January, 1972 and December, 1991, there were twenty-eight cases of nephroblastoma and one of mesoblastic nephroma. Peak incidence was between the ages of two and four years. Twenty-five children had radical nephrectomy while one had bilateral partial nephrectomy. In thirteen cases, pre-operative chemotherapy +/- radiotherapy was used. Post-operative chemotherapy and radiotherapy were used in 24 and 13 cases, respectively. Stage of the tumour was the most decisive factor influencing the outcome. Whereas there was a 100% cure rate in Stages I and II, Stage III had only a 55.5% survival rate and none of the Stage IV survived. Bilateral (Stage V) tumours are curable if individual tumours are localised, as in one of the two cases. The benign mesoblastic nephroma, in a one-month-old infant, was cured by nephrectomy alone. While the present therapy of radical nephrectomy along with combination chemotherapy is satisfactory for early stages, more aggressive adjuvant therapy is needed for improving the results in Stages III and IV.

Child↗
PubMed1994

The Rapunzel syndrome. Report of a case and review of the literature.

The Rapunzel Syndrome, a rare manifestation of trichobezoar, occurs when bolus gastrointestinal obstruction is produced by an unusual trichobezoar with a long tail that extends to or beyond the ileocaecal valve. A five-year-old Jamaican girl presented with this abnormality and was found at laparotomy also to have an ileo-ileal intussusception. For the Rapunzel Syndrome, we recommend bezoar extraction at laparotomy via multiple enterotomies. In addition, psychiatric evaluation and therapy is essential due to the commonly associated finding of underlying emotional stress.

Bezoars↗
PubMed1994

Effect of body position on spontaneous respiratory rate and tidal volume in patients with obesity, abdominal distension and ascites.

BACKGROUND: Nursing textbooks and tradition suggest that the high-Fowler's position is best to optimize diaphragmatic excursion and effective breathing pattern. The optimal position for intubated patients with obesity, ascites or abdominal distention has yet to be determined but is important because weaning trial outcomes may reflect the effect of position rather than weaning trial tolerance. OBJECTIVE: To determine the body position that optimizes breathing pattern (tidal volume and respiratory rate) in spontaneously breathing, intubated patients with a large abdomen. METHODS: Nineteen intubated patients with abdominal distention, ascites or obesity who were on continuous positive airway pressure or the pressure support ventilation mode were studied in the 0 degrees, 45 degrees, 90 degrees and reverse Trendelenburg's at 45 degrees positions for 5 minutes prior to data collection. RESULTS: The RT at 45 degrees position resulted in a significantly larger tidal volume and lower respiratory rate than the 90 degrees position in intubated, spontaneously breathing patients with a large abdomen. The 45 degrees position resulted in a significantly lower respiratory rate than at 90 degrees; however, no difference in tidal volume was demonstrated. DISCUSSION: A high respiratory rate and low tidal volume potentiates atelectasis and ultimately failure to wean. It is important that the effect of positioning on breathing pattern in intubated patients be determined so that care planning results in optimal outcomes. CONCLUSIONS: The results of this study have implications for the selection of chair and bed positioning during weaning trials.

Adult↗
PubMed1993

Complementary floral homeotic phenotypes result from opposite orientations of a transposon at the plena locus of Antirrhinum.

Recessive mutations at the plena (ple) locus result in a homeotic conversion of sex organs to sterile perianth organs in flowers of Antirrhinum majus. A complementary phenotype, in which sex organs replace sterile organs, is conferred by semidominant ovulata mutations. The ple locus was identified and isolated using a homologous gene, agamous from Arabidopsis, as a probe. The expression of ple is normally restricted to the inner two whorls of the flower, where sex organs develop. However, in ovulata mutants, ple is expressed ectopically in the outer two whorls of the flower and in vegetative organs. These mutants correspond to gain-of-function alleles of ple, suggesting that ple is sufficient for promoting sex organ development within the context of the flower. The plena and ovulata phenotypes result from opposite orientations of the transposon Tam3 inserted in the large intron of ple.

Alleles↗
PubMed1993

Olive: a key gene required for chlorophyll biosynthesis in Antirrhinum majus.

Olive (oli) is a recessive nuclear mutation of Antirrhinum majus which reduces the level of chlorophyll pigmentation and affects the ultrastructure of chloroplasts. The oli-605 allele carries a Tam3 transposon insertion which has allowed the locus to be isolated. The oli gene encodes a large putative protein of 153 kDa which shows homology to the products of two bacterial genes necessary for tetrapyrrole-metal chelation during the synthesis of bacteriochlorophyll or cobyrinic acid. We therefore propose that the product of the oli gene is necessary for a key step of chlorophyll synthesis: the chelation of magnesium by protoporphyrin IX. Somatic reversion of the oli-605 allele produces chimeric plants which indicate that the oli gene functions cell-autonomously. Expression of oli is restricted to photosynthetic cells and repressed by light, suggesting that it may be involved in regulating the rate of chlorophyll synthesis in green tissues.

Amino Acid Sequence↗
PubMed1993

Comparison of peripheral chemoreceptor responses in monozygotic and dizygotic twin infants.

The peripheral chemoresponses of infant twin pairs were determined using a single-breath hyperoxic stimulus. A total of 43 twin pairs of comparable gestation and birth weight were studied during sleep at a mean (SD) age of 8 wk (1.4) while alternately breathing either air or 16% oxygen in nitrogen. Infants responded to a single breath of 100% oxygen by a reduction in ventilation; the mean (SEM) reduction in air was 273 ml/min (10.6) and in 16% oxygen 560 ml/min (18.4). Within-pair variances were compared in 14 monozygotic and 28 dizygotic pairs utilizing combined responses (air + 16% oxygen) computed for measurements made in behavioral quiet sleep and in 9 monozygotic and 20 dizygotic pairs for whom data were complete in polygraphically confirmed quiet sleep. The variance of responses within dizygotic twin pairs was greater than in monozygotic pairs when expressed in ml/min: F ratio 4.11 (p = 0.005) for all data and F ratio 7.67 (p = 0.003) in quiet sleep. Expressed in ml/min/kg the difference was less significant: F ratio 1.83 (p = 0.126) for all data and F ratio 3.46 (p = 0.039) in quiet sleep. Gender, birth weight, and birth order had no effect on these findings. This closer similarity of response in monozygotic twin pairs is explained by proposing a high degree of heritability for the response.

Chemoreceptor Cells↗
PubMed1993

The nature and significance of multiple isoforms of the oestrogen receptor in breast tumours.

Oestrogen receptors (ERs) in breast tumours are highly heterogeneous. In previous studies we have shown that at least four isoforms may exist. These migrate in isoelectric focusing (IEF) gels to isoelectric points (pI values) 6.1, 6.3, 6.6 and 6.8. Of these the first (pI 6.1) corresponds to the 8S isoform as detected by sucrose gradient fractionation, while the others all sediment at 4S. In a series of 66 breast tumours it was found that those at pI 6.3 and pI 6.8 were significantly correlated with the presence of progesterone receptors. To characterize the isoforms more fully, ER isoforms labelled by [3H]oestradiol binding were fractionated by IEF. The results were compared with those obtained after sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting using the H222 anti-ER monoclonal antibody. In other experiments, tumour ER isoforms were covalently labelled with [ring-3H] tamoxifen aziridine and separated by IEF. The individual isoforms were electroeluted from the IEF gel and further analysed by SDS-PAGE and non-denaturing PAGE. In summary, the evidence shows that the isoforms of pI values 6.3, 6.8 and 6.6 have molecular masses of 50, 65 and 70 kDa respectively. In addition, all three of these isoforms, i.e. the pI 6.3, 6.8 and 6.6 isoforms, could form dimers. We conclude that the three isoforms sedimenting at 4S have the capacity to form dimers and thus may have the potential for binding to oestrogen response elements in the genome.

Blotting, Western↗
PubMed1993

The comparative costs of care using apnoea monitors and scales in families with a cot death.

This paper reports the findings from a programme, which provided support to families with a subsequent baby following a cot death. One hundred families participated in the study. Fifty families were randomly allocated apnoea monitors, and the remainder provided with scales and weight charts for daily weighing. The results show that the parents in both groups expressed equal satisfaction with their designated method. However, compared with families allocated scales, those using apnoea monitors attended the child health clinics more often, and the number of contacts with the paediatrician was increased. They also had slightly more home and general practitioner contacts and hospital admissions. The capital and running costs of providing monitors was also greater for this group.

Apnea↗
PubMed1993

Hydrops of the gallbladder.

Hydrops of the gallbladder is an uncommon condition of infants and children. There is acute distension of the gallbladder in the absence of calculi without evidence of inflammation in the early stages of the disease. A case of hydrops of the gallbladder in a 4-year-old male child is presented. The literature is reviewed and the diagnosis and treatment of the condition discussed.

Anti-Bacterial Agents↗
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↗