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Biomedical subjects

M Wells

Publications and source records attributed to M Wells.

At least 91 records · Page 5Linked to original sources
PubMed1995

Early closure of colostomies in trauma patients--a prospective randomized trial.

BACKGROUND: Most traumatic colon injuries can be repaired primarily, but a colostomy may still be required for severe colonic or rectal injury. The current trend is to reverse the colostomy early, rather than to wait the traditional 3 months before closure. METHODS: Forty-nine patients with colostomies after abdominal trauma were entered into the study. All patients had undergone a contrast enema in the second postoperative week to assess distal colon healing. Patients were excluded from early closure for nonhealing of the bowel injury, unresolving wound sepsis, or an unstable condition. We then compared the outcome of the remaining 38 (77.6%) patients allocated to either an early or a late colostomy group in a controlled, prospective, randomized trial. RESULTS: We found no significant difference in morbidity between the two groups, with an overall complication rate of 26.3%. Technically the early closure of colostomies was far easier than late closure and required significantly less operating time (p = 0.036) and with less intraoperative blood loss (p = 0.020). The closure of end colostomies was more time consuming, both early (p < 0.001) and late (p < 0.001) and caused more bleeding (p < 0.001 and p < 0.001, respectively). Total hospitalization was marginally shorter overall for early closure, but late closure of end colostomies resulted in prolonged hospitalization (p = 0.023). CONCLUSIONS: The early closure of colostomies and the use of loop colostomies whenever possible are recommended as both safe and beneficial for patients with colonic injury after trauma. Contraindications for early closure include nonhealing distal bowel, persistent wound sepsis, or persistent postoperative instability.

Adolescent↗
PubMed1995

p53 protein expression in putative precursor lesions of epithelial ovarian cancer.

p53 protein expression has been studied in epithelial inclusion cysts adjacent to and contralateral to serous carcinoma of the ovary and compared to epithelial inclusion cysts associated with borderline tumours and in normal ovaries. Atypia was found in epithelial inclusion cysts in eight of the thirteen advanced (stage III) serous ovarian carcinomas. Of these eight with atypical epithelial inclusion cysts, five showed immunoreactivity for p53. In the borderline tumours and normal ovaries no atypia in such cysts was found. p53 expression was also seen more frequently in surface epithelium associated with ovarian serous adenocarcinoma (ten of 13) than in normal ovaries (one of 13). We postulate that focal areas of atypia (ovarian intra-epithelial neoplasia) in epithelial inclusion cysts are the precursors of ovarian malignancy. In some cases, at least, p53 protein expression may precede overt cytological abnormalities.

Adult↗
PubMed1995

The control of ventilatory and cardiac responses to changes in ambient oxygen tension and oxygen demand in octopus

Octopus vulgaris can regulate its oxygen uptake down to a PO2 of around 6.7 kPa. As the tension falls from 18.6 to 6.7 kPa (140 to 50 mmHg), Pv (the pressure pulse driving the ventilatory flow, measured inside the mantle cavity) can more than double while fv (the ventilation frequency) increases by a few per cent at most. Both changes are reversed when the ambient oxygen tension is returned to normal. Cutting the visceral nerves linking the hearts and gills to the brain prevents these adaptive changes in Pv and fv, as does section of the branchial nerves linking the cardiac ganglia to the gills. Responses to changes in ambient oxygen tension are very fast, beginning within two or three ventilation cycles. It is concluded that changes to Pv and fv depend upon receptors in the gills and on the integrity of a nervous pathway to the brain. Changes in oxygen tension also affect the hearts, where aortic pulse amplitude (Pa) and, to a lesser extent, heartbeat frequency (fh) fall and rise with the ambient PO2. In this case, section of the visceral or branchial nerves has no effect. Responses are again very rapid. It is concluded that the observed fall and return to normoxic values of Pa and fh are local responses to a fall and rise in the oxygen tension of blood coming from the gills into the systemic heart. Changes to ventilation and heartbeat can also occur in normoxic water when oxygen demand rises after feeding. These responses are not prevented by section of the visceral or branchial nerves. Possible control of ventilation and heartbeat through the neurosecretory system in the anterior vena cava is discussed.

Journal Article↗
PubMed1995

Is dietary erucic acid hepatotoxic in pregnancy? An experimental study in rats and hamsters.

The hypothesis that dietary erucic acid may contribute to the pathogenesis of intrahepatic cholestasis of pregnancy has been examined in pregnant rats and hamsters after prolonged feeding of diets containing 25% rapeseed oil rich in erucic acid (40% of fatty acids) or corn oil, without erucic acid. Both dietary oils were well tolerated, although weight gain was 17% to 20% less in animals receiving rapeseed oil. Rats and hamsters were studied on the last day of pregnancy and compared with age- and diet-matched nonpregnant animals. Histological examination showed no major morphologic abnormalities in liver, heart, kidneys, and adrenals. Similar microscopic deposits of fat were found in the livers and hearts of pregnant hamsters of both dietary groups. Chromatographic analysis of fatty acids in liver, heart, and kidney homogenates of hamsters and in isolated rat liver cells reflected the fatty acid composition of the dietary oils: oleic (18:1) and linoleic (18:2) acids were among the predominant fatty acids. Erucic acid was found in a higher proportion in the heart (14% by weight of total fatty acids) than in the liver (3%) and kidneys (3%) of animals fed rapeseed oil. Bile flow and biliary lipid composition was similar in rats and hamsters fed rapeseed or corn oil. Bile flow tended to be less in pregnant than in nonpregnant animals. Pregnant hamsters fed rapeseed oil tended to have the lowest bile flow. The lithogenic index of bile was slightly decreased in pregnant rats and increased in pregnant hamsters, although these proportional changes were similar for both diets. In all circumstances the lithogenic index remained below a value of 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1994

Is the timing of withdrawal bleeding a guide to endometrial safety during sequential oestrogen-progestagen replacement therapy? UK Continuous Combined HRT Study Investigators.

Current regimens of sequential hormone replacement therapy are based on data that show a protective effect on the endometrium of at least 10 days of progestagen. In clinical practice, onset of bleeding on or after day 11 of the progestagen phase is taken as reassurance of a normal endometrium. 413 postmenopausal women taking oestrogen-progestagen hormone replacement therapy with 10 or 12 days of progestagen per cycle completed bleeding diaries for 3 months before endometrial biopsy. For most women, bleeding started around the 13th day after starting progestagen. There was no correlation between endometrial histology and timing of onset of bleeding. 11 (2.7%) women had complex endometrial hyperplasia. The prevalence of hyperplasia was 2.4% with 10 days of progestagen per cycle and 2.8% with 12 days [corrected]. The timing of onset of withdrawal bleeding during oestrogen-progestagen HRT does not predict endometrial hyperplasia.

Endometrium↗
PubMed1994

Human papilloma viruses: a study of their prevalence in the normal larynx.

The association of human papilloma viruses (HPV) with laryngopharyngeal squamous cell carcinoma is under investigation. The suitability of control tissue in the reported series, invariably obtained from histologically normal tissue adjacent to a squamous cell carcinoma or from patients with benign laryngopharyngeal disease, is questionable. The present study determined the prevalence of HPV in a series of normal larynges. Twelve autopsy larynges were collected. DNA was obtained by SDS proteinase K digestion. Evidence of HPV infection was documented by the polymerase chain reaction using oligonucleotide primers complementary to sequences in the E6 region of HPV types 11, 16 and 18. Four female and eight male larynges, mean age 65 years (SD = 16 years) were collected 72 hours postmortem (median value). HPV type 11 was isolated from three specimens. A 25 per cent prevalence rate for HPV 11 was found. No other HPV types were isolated.

Adult↗
PubMed1994

Immunoreactivity of antibodies to epidermal growth factor, transforming growth factors alpha and beta, and epidermal growth factor receptor in the premenopausal ovary.

This study provides a valuable insight into the localization of growth factors in paraffin sections of human ovarian tissue. Antibodies to epidermal growth factor (EGF), transforming growth factors alpha and beta (TGF alpha and beta) and epidermal growth factor receptor (EGFR) were applied to paraffin sections of 16 cases of formalin-fixed normal or benignly abnormal ovarian tissue. All growth factor antibodies reacted with theca, but not granulosa cells, whilst the antibody to EGFR reacted with both types of follicular cells and was weakly reactive in ovarian stroma. There were no discernible qualitative changes in reactivity during the follicular cycle. These immunohistochemical findings generally support previously published molecular and biochemical data from tissue culture. One exception is in the observation of immunoreactivity to EGF in theca and granulosa cells. This may be due to differences in sensitivity of the methods in use. The possibility of a cross-reaction of the anti-EGF antibody with TGF alpha is also discussed. This study provides evidence for both paracrine and autocrine roles for growth factors in folliculogenesis.

Adult↗
PubMed1994

Ovarian metastasis from thyroid carcinoma 12 years after partial thyroidectomy mimicking struma ovarii: report of a case.

A 29-year-old woman experienced abdominal swelling 12 years after undergoing partial thyroidectomy for follicular carcinoma of the thyroid with vascular invasion and 6 months after a right cerebral tumor that had caused hemiplegia had been excised. Laparotomy disclosed a solid and cystic right ovarian tumor, 17 cm in greatest dimension, and a 12-cm tumor of the right adrenal gland. Microscopic examination showed a malignant tumor of the thyroid follicular type with frequent mitotic figures; other teratomatous elements were absent. Because of the interval since the thyroid cancer, the diagnosis of a malignant struma ovarii was initially considered. The patient rapidly developed widespread metastatic disease and died, supporting the interpretation that the ovarian tumor was a metastasis from the thyroid neoplasm. This case illustrates that when other teratomatous elements are not identified, the diagnosis of malignant struma ovarii should be made only when the possibility of spread from a prior thyroid neoplasm, possibly one treated many years previously, has been excluded.

Adenocarcinoma, Follicular↗
PubMed1994

Characterisation of complex carbohydrates in cervical glandular intraepithelial neoplasia and invasive adenocarcinoma.

Using a panel of 11 biotinylated lectins and an avidin-peroxidase detection system on paraffin sections of formalin-fixed material, the range of expression of N-linked glycoprotein backbone structures and glycoprotein terminal structures was established in normal cervical glands. A characteristic pattern of luminal lectin reactivity was noted in areas of glandular tubal metaplasia. A consistent change in the topographic distribution of carbohydrate structures in cervical glandular neoplasia was found. In contrast to cytoplasmic expression in normal glands, 90% of adenocarcinomas, 92% of cases of high-grade cervical glandular intraepithelial neoplasia, and 63% of cases of low-grade cervical glandular intraepithelial neoplasia showed novel linear expression along the lumina of glands. The results indicate molecular as well as morphological similarities between invasive adenocarcinomas and putative preinvasive glandular lesions.

Adenocarcinoma↗
PubMed1994

Human papilloma viruses in the human hypopharynx.

The possible association of human papilloma viruses (HPV) with laryngopharyngeal squamous cell carcinoma is under investigation. Recent work suggests regional differences in the prevalence of HPV infection in the hypopharynx. The present study investigates the prevalence of HPV in tissue obtained from a series of piriform fossae. Piriform fossa epithelium was harvested from 12 autopsy cases free of local disease. DNA was obtained by SDS/Proteinase K digestion. Evidence of HPV infection was documented by the polymerase chain reaction using oligonucleotide primers complementary to sequences in the E6 region of HPV types 11, 16 and 18. All the specimens were positive for beta-globin. HPV11 was isolated from two patients. None were positive for HPV16 or HPV18. An 18% prevalence rate for HPV11 in the normal human hypopharynx was found.

Aged↗
PubMed1993

Semiquantitative immunohistochemical studies of blood group antigen A, B, H, Le(a), Le(b) structures and Ii backbone chains in the normal human cervix and in cervical adenocarcinoma.

Epithelia frequently express blood group antigens and these are often perturbed in neoplasia. This study has characterized the range of expression of ABH and Lewis terminal structures and the Ii backbone chains in the normal human cervix by semiquantitative immunohistochemistry. Effects of the secretor gene were defined by determination of salivary secretor status. Modifications of blood group antigen expression in cervical adenocarcinoma were also addressed. Normal cervical squamous and glandular epithelia showed a range of expression of the antigens studied. Lewis-gene-negative cases showed no expression of Lewis antigens. Secretor status had no effect on ABH expression in squamous epithelium, but it did have a marked effect on ABH expression in glands and on Le(b) expression in both squamous and glandular epithelia. Patterns of expression of i chains in squamous epithelium suggest that these may be the carriers of ABH and Lewis antigens in a proportion of cases. Distinct patterns of expression were seen in glandular tubal metaplasia and in endothelium. Adenocarcinomas showed topographical rather than quantitative changes in blood group antigen expression with more extensive luminal expression of ABH, Lewis and Ii structures than that seen in normal glands. This change is distinct from those usually associated with malignancy.

ABO Blood-Group System↗
PubMed1993

Pediatric facial fractures: evolving patterns of treatment.

This study reviews the treatment of facial trauma between October 1986 and December 1990 at a major pediatric referral center. The mechanism of injury, location and pattern of facial fractures, pattern of facial injury, soft tissue injuries, and any associated injuries to other organ systems were recorded, and fracture management and perioperative complications reviewed. The study population consisted of 137 patients who sustained 318 facial fractures. Eighty-one patients (171 fractures) were seen in the acute stage, and 56 patients (147 fractures) were seen for reconstruction of a secondary deformity. Injuries in boys were more prevalent than in girls (63% versus 37%), and the 6- to 12-year cohort made up the largest group (42%). Most fractures resulted from traffic-related accidents (50%), falls (23%), or sports-related injuries (15%). Mandibular (34%) and orbital fractures (23%) predominated; fewer midfacial fractures (7%) were sustained than would be expected in a similar adult population. Three quarters of the patients with acute fractures required operative intervention. Closed reduction techniques with maxillomandibular fixation were frequently chosen for mandibular condyle fractures and open reduction techniques (35%) for other regions of the facial skeleton. When open reduction was indicated, plate-and-screw fixation was the preferred method of stabilization (65%). The long-term effects of the injuries and the treatment given on facial growth remain undetermined. Perioperative complication rates directly related to the surgery were low.

Accidents, Traffic↗