Biomedical subjects
Publications and source records attributed to M O'Brien.
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Thirty-three evaluable patients who had epithelial ovarian cancer that had not responded to treatment were entered into a phase II study of combination epirubicin and mitomycin C. Epirubicin (65 mg/m2) and mitomycin C (4 mg/m2) were administered separately, each as an i.v. bolus every 4 weeks. Ten patients (30%) had a complete or partial responses. The median duration of response was 20 weeks (range, 9-53). The regimen was well tolerated. Myelotoxicity occurred in four patients requiring hospitalization for septicaemia. Eleven patients had a blood transfusion. Alopecia was common, and nausea and vomiting, though frequent, usually mild. Cardiological toxicity was observed in one patient only. She developed congestive cardiac failure after an acute myocardial infarction. This regimen is active in advanced ovarian cancer that has not responded to prior treatment and warrants further study combination with other active drugs as a first-line regimen for ovarian cancer.
UNLABELLED: The load carrying capacity (LCC) of the human spine was evaluated in 10 human cadaver spines. The specimens consisted of segments from T11 to S1 with markers placed on the specimens at each vertebral level in both Ap and lateral planes. The specimens were loaded to 1250 N and spinal deflections were recorded and photographed at 125 N intervals during the loading cycle. In 5 specimens, axial and flexion loads were applied to the intact spine. The anterior and middle columns were destroyed in sequence at L2 and the loading process repeated. In the remaining 5 specimens, axial and extension loads were applied with the spine intact and after the posterior and middle columns were destroyed in sequence at L2. Load deflection curves were generated for each test and comparisons were made between intact spines and spines with single and double column destruction. RESULTS: When the axis of loading was anterior to the posterior longitudinal ligament (PLL), destruction of the anterior and middle columns reduced the LCC by 46% and 68% respectively and destruction of the posterior and middle columns reduced the LCC by 30% and 63% respectively. There was minimal change in the LCC when the axis of loading was posterior to the PLL and the anterior and middle columns were destroyed. Two column destruction of the spine reduced its load carrying capacity for flexion loads by 70%. In thoracolumbar spinal fractures where flexion loads are predominant and anticipated, the authors conclude that surgical stabilisation is indicated with double column failure.
A function of the spine as a structural column is its ability to resist torsion. The goal of this study was to evaluate the contribution of the columns of the spine to torsional rigidity. Ten human cadaver spines were harvested and frozen. The specimens, consisting of segments from T11 to S1, were subjected to torsional loads of up to 20 N-m. Rotation was recorded throughout the loading cycle. The columns of the spine were destroyed at the L2-3 interspace in a predetermined fashion and loading was repeated. The data were plotted as torsion versus rotation in degrees. The curves of each loading cycle were compared and the ratios of the intact and compromised specimens were calculated. The contribution of each column of the spine to torsional rigidity was determined. In an intact lumbar spine, the anulus was the most effective structure in resisting torsion. Experience gained in this study supports the following conclusion: Flexion-distraction injuries of the thoracolumbar and lumbar spine involving soft tissue destruction of the anterior column and anulus result in rotational instability.
We studied 11 glomus tumours immunohistochemically, with a panel of connective tissue and epithelial markers. Most tumours contained small nerve fibres located in connective tissue septae between groups of glomus cells, thus accounting for the frequent occurrence of pain associated with glomus tumours. All tumours stained positively for muscle-specific actin and vimentin. Immunostaining for high and low molecular weight cytokeratins, desmin, myoglobin, S-100 protein, neurofilaments and Factor VIII related antigen was negative. Our findings confirm and amplify the proposed smooth muscle histogenesis of glomus tumours. This immunohistochemical profile may be of diagnostic value in the differential diagnosis of atypical glomus tumours.
Children as young as 18 months display sex-stereotyped toy choices. The present study was designed to determine whether parents encourage involvement with sex-stereotyped toys or avoidance of cross-sex-stereotyped toys and to determine whether masculine and feminine toys lead to different patterns of parent-child interaction, regardless of gender. 40 parent-toddler dyads were videotaped while playing with 6 different sets of sex-stereotyped toys. Equal numbers of boys and girls were observed with mothers and fathers. The children showed greater involvement when playing with same-sex-typed toys than with cross-sex toys even when statistically controlling for parents' behaviors. Parents' verbal behaviors, involvement, and proximity to the child differed across toy groups, regardless of the parent's or child's gender. Parents' initial nonverbal responses to the toys, however, were more positive when the toys were stereotyped for the child's and parent's gender than when they were not.
A prior report has suggested that loading doses of intraperitoneal Vancoled (vancomycin, Lederle) cause chemical peritonitis in patients with catheter infections. The present open-label study was conducted to determine the effects of a 30 mg/kg intraperitoneal loading dose of Vancoled given to five patients with a culture-positive, erythematous, draining exit-site infection. Prior to dosing, all dialysate was drained and sent for baseline cell count and culture. The loading dose was added to the dialysate and infused in the usual fashion. A sample of dialysate was drained at two hours and sent for cell count and culture. The entire exchange was drained at four hours and also sent for cell count and culture. Serum vancomycin concentrations wer measured at four hours. Baseline dialysate contained less than 9 white blood cells per microliter in all patients. Two and four hour samples contained less than 4 and less than 11 white blood cells per microliter, respectively. All fluid was sterile. WB C differential counts were unremarkable. No adverse effects occurred. The mean serum vancomycin concentration was 26.5 micrograms/ml. Intraperitoneal Vancoled did not cause chemical peritonitis and was well-tolerated by patients with exit-site infections.
An enzymatic characterization of 16 strains of Aeromonas species including A. hydrophila (7), A. sobria (5), and A. caviae (4) was carried out using API Peptidase (strips numbered 1, 2, 3, 4, 5, and 6); API Esterase and API "Osidase" test strips. A total of 89 substrates was used in the assay and included 59 arylamides (aminopeptides), 10 esters, and 20 carbohydrates. All three species were remarkably uniform in their reactivities. Nineteen (32%) of the arylamide substrates used were hydrolyzed by all three species. Very strong arylamidase activity was displayed by all three species for L-lysine, L-hydroxyproline, L-arginine, L-alanine, L-proline, and L-leucyl-L-alanine. Esterase activity was strongest against caproate (C6), caprylate (C8), nonanoate (C9), and caprate (C10) substrates. Only a limited number of carbohydrate substrates were hydrolyzed; strong N-acetyl-beta-D-glucosaminidase activity was given by all strains. Both A. hydrophila and A. caviae gave strong beta-D-glucosidase reactivities, while A. sobria appeared to be negative for this enzyme. The results of our preliminary study show that some of the enzymes examined may be useful in the identification and differentiation of these species. The API enzyme assays yielded rapid (4 hr) results. The assays were easy to perform, relatively inexpensive and reproducible. The importance of replicate testing and the inclusion of uninoculated (buffer only) controls as part of the assay is emphasized.
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We describe a patient with disseminated sarcoidosis, who had granulomatous enterocolitis with radiological narrowing of the terminal ileum, and was presumed to have Crohn's disease. At autopsy, there were numerous sarcoid-like granulomata throughout the mucosa of the large and small bowel, but no transmural inflammation, lymphoid aggregates, or strictures, thus making Crohn's disease unlikely. It is proposed that a granulomatous enterocolitis resembling Crohn's disease can be a manifestation of disseminated sarcoidosis.
Forty six cadaveric lower limbs were examined to define the presence, site and shape of the tendinous interruption in semitendinosus. It was found to be: 1. Present in all limbs studied. 2. Single in all limbs studied. 3. V-shaped with a short lateral limb and a long medial limb measuring one fifth of the total muscle length. 4. Its apex is one third of the total muscle length from the origin of the muscle.
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The interval from the onset of symptoms to the diagnosis in 79 children with primary brain tumors was compared with that in 45 children with Wilms' tumor and 123 children with acute leukemia. The patients with brain tumors had a significant delay from symptom onset to diagnosis. Only 38% of primary brain tumors were diagnosed within the first month after the onset of symptoms. In contrast, 84% of Wilms' tumors and 80% of cases of acute leukemia were diagnosed within one month of the onset of symptoms. Early detection of brain tumors is important as it may have a significant bearing on clinical outcome.
Three species of colonic bacteria can ferment the mucopolysaccharide chondroitin sulfate: Bacteroides ovatus, Bacteroides sp. strain 3452A (an unnamed DNA homology group), and B. thetaiotaomicron. Proteins associated with the utilization of chondroitin sulfate by B. thetaiotaomicron have been characterized previously. In this report we compare chondroitin lyases and chondroitin sulfate-associated outer membrane polypeptides of B. ovatus and Bacteroides sp. strain 3452A with those of B. thetaiotaomicron. All three species produce two soluble cell-associated chondroitin lyases, chondroitin lyase I and II. Purified enzymes from the three species have similar pH optima, Km values, and molecular weights. However, peptide mapping experiments show that the chondroitin lyases from B. ovatus and Bacteroides sp. strain 3452A are not identical to those of B. thetaiotaomicron. A cloned gene that codes for the chondroitin lyase II from B. thetaiotaomicron hybridized on a Southern blot with DNA from B. ovatus or Bacteroides sp. strain 3452A only when low-stringency conditions were used. Antibody to chondroitin lyase II from B. thetaiotaomicron did not cross-react with chondroitin lyase II from B. ovatus or Bacteroides sp. strain 3452A. Chondroitin lyase activity in all three species was inducible by chondroitin sulfate. B. ovatus and Bacteroides sp. strain 3452A, like B. thetaiotaomicron, have outer membrane polypeptides that appear to be regulated by chondroitin sulfate, but the chondroitin sulfate-associated outer membrane polypeptides differ in molecular weight. Despite these differences, the ability of intact bacteria to utilize chondroitin sulfate, as indicated by growth yields in carbohydrate-limited continuous culture and the rate at which the chondroitin lyases were induced, was the same for all three species.
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A retrospective study of 460 single-gestation infants in breech position was conducted at the University of Colorado Medical Center to assess the impact of a policy for the selection of cases for vaginal delivery. Among infants weighing more than 2,500 grams, there was an increase in the cesarean section rate from 13% to 54%, with an associated increase in maternal morbidity from 7% to 15%. This occurred with no significant reduction in adverse perinatal outcome. However, a case-by-case review suggests that more frequent and timely cesarean sections would have further reduced perinatal morbidity and deaths among term infants. Among the infants weighing 2,500 grams or less there was an increase in cesarean births from 5% to 55% following the introduction of the strict criteria for vaginal delivery. Among the infants weighing 1,501 to 2,500 grams there was no significant difference in survival between the cesarean and vaginally delivered patients. Although infants weighing 501 to 1,500 grams delivered by cesarean section survived more frequently than did those delivered vaginally, the differences in perinatal deaths may have been due to a higher birth weight in the cesarean-delivered infants or an over-all improvement in neonatal intensive care for infants of very low birth weight.
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