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Biomedical subjects

J Harper

Publications and source records attributed to J Harper.

At least 109 records · Page 6Linked to original sources
PubMed1991

Preincubation of human granulosa cells with gonadotrophin prevents the cloprostenol-induced inhibition of progesterone production.

Human granulosa cells, from women undergoing ovum collection for in-vitro fertilization (IVF), will luteinize in vitro and provide a model for investigating the antigonadotrophic action of a prostaglandin F2 alpha (PGF2 alpha) analogue, cloprostenol, on granulosa-derived luteal cells. The granulosa cells were cultured in a defined medium and exposed to treatments during a preincubation period of 0 to 3 days and a final incubation with low density lipoprotein (LDL) from days 3 to 4. In the absence of human chorionic gonadotrophin (HCG), progesterone production was low, whereas exposure to HCG in the final incubation resulted in a 10-fold increase in progesterone concentrations. The inclusion of cloprostenol with HCG in the final incubation significantly (P less than 0.05) inhibited HCG-stimulated progesterone production. Exposure to HCG during the preincubation prevented the antigonadotrophic action of cloprostenol in the final incubation. The antigonadotrophic action of cloprostenol was retained when the granulosa cells were exposed to cloprostenol during the preincubation. Omission of LDL from the final incubation lowered the production of progesterone but the pattern of responses to HCG and cloprostenol were similar. Prevention of the antigonadotrophic action of cloprostenol after exposure to HCG may be a mechanism through which chorionic gonadotrophin can prevent regression of the corpus luteum in early pregnancy. Cloprostenol does not appear to inhibit LDL-stimulated steroidogenesis in human granulosa cells.

Cells, Cultured↗
PubMed1991

High-dose carboplatinum and VP-16 in treatment of metastatic adrenal carcinoma.

We describe a case of a patient that presented to our center with Cushing syndrome and was found to have an extensive metastatic adrenal carcinoma. He underwent debulking of the abdominal disease followed by eight courses of VP-16/carboplatinum. The patient had a remarkable response and is currently alive and in complete remission.

Adrenal Cortex Neoplasms↗
PubMed1991

Predicting cholangiocarcinoma in patients with primary sclerosing cholangitis before transplantation.

Patients with primary sclerosing cholangitis are at an increased risk of developing cholangiocarcinoma, which is difficult to diagnose because the biliary tree is already distorted. Eleven patients with primary sclerosing cholangitis who underwent orthotopic liver transplantation at this hospital were evaluated. Four patients had coincidental histologically proved cholangiocarcinoma. Patients with cholangiocarcinoma in contrast to patients without tumour presented with rapid onset of persistent jaundice, pruritus, and weight loss associated with an appreciable rise in bilirubin (8x v 2x) and alkaline phosphatase (3.5x v 1.2x) over one year. Cholangiography and computed tomography showed appreciably dilated intrahepatic bile ducts (3/4 v 0/7). The diagnosis of cholangiocarcinoma could only be established before operation in one patient by fine needle aspiration cytology. Tumour was recognised at operation in one other. Histological examination of hepatectomy specimens showed that patients with cholangiocarcinoma had less advanced histological features of primary sclerosing cholangitis. Multiple areas of carcinoembryonic antigen positive epithelial atypia and carcinoma in situ were found in all patients with cholangiocarcinoma. Cholangiocarcinoma recurred in two patients at 14 and 39 months after transplantation. Superimposed cholangiocarcinoma can be predicted in most patients with cholangitis before transplantation, although a definitive diagnosis is difficult to make. Their prognosis after successful transplantation is guarded.

Adenoma, Bile Duct↗
PubMed1990

Transfallopian tube embryo transfer: successful pregnancy outcome.

A case of partial Asherman syndrome and blocked fallopian tube following complication of cesarean section is presented. Two IVF-ET attempts failed where difficulty at uterine embryo transfer was encountered. Transtubal embryos transferred 48 hr after transvaginal oocyte collection and in vitro fertilization resulted in an in utero pregnancy and delivery.

Adult↗
PubMed1990

Neonatal hemangiomatosis presenting as infantile spasms.

The previously unreported association of neonatal hemangiomatosis and infantile spasms is described in a 4-month-old female. The high mortality and morbidity of this neurocutaneous syndrome necessitates prompt recognition and investigation, to enable identification of associated internal lesions.

Brain Neoplasms↗
PubMed1990

A center-based program for exercise change among black-American families.

A center-based program was designed and implemented to promote aerobic physical activity among healthy Black-American families with children in the fifth through seventh grades. Ninety-four Black-American families were actively recruited and randomly assigned to an experimental or control group. Families in the experimental group were encouraged to participate in a program with the following features: one education and two fitness sessions per week for 14 weeks; educational sessions that included individual counseling, small group education, aerobic activity, and snack components; located in a convenient building cherished by the community; aerobic activity sessions in a fitness center outfitted and staffed according to modern characteristics; a variety of incentives including free transportation and babysitting and reminders to promote attendance. Percent participation was low, with about 20% participating in the desired fitness center sessions by the end of the program. As a result of low participation, no differences were detected between experimental and control groups on indicators of cardiovascular fitness. In postprogram interviews, conflicts with work and school events were the most commonly reported reasons for nonattendance. We concluded that because of difficulties in attendance, center-based programs appear to have limited value as the sole modality for intervention in public health programs for promoting physical activity among healthy, low income Black-American families with young children. More comprehensive community-based programs are likely to be needed.

Adult↗
PubMed1990

Rhabdomyolysis and myoglobinuric renal failure.

Rhabdomyolysis, a clinical syndrome resulting from the release of skeletal muscle cell contents into the plasma, is causally connected to up to 25 percent of all cases of acute renal failure. Critical care nurses need to be aware of precipitating factors and proper interventions in order to assure optimal function in this patient population.

Acute Kidney Injury↗
PubMed1989

Collagenases from periarticular ligaments and tendon: enzyme levels during the development of joint contracture.

Our laboratories have previously demonstrated that normal rabbit periarticular ligaments, anterior cruciate ligaments (ACL), medial collateral ligaments (MCL) and patellar tendon (PT) secrete collagenase. In this current study we examined these connective tissues following an immobilization period of 4 weeks. In the ligaments producing collagenase, activity was expressed only in the control, not in the immobilized joint. Control and experimental patellar tendon samples produce collagenolytic activity, suggesting that the expression of enzyme is less affected in tendons as compared to ligaments. Characterization of these collagenases was carried out using an antiserum directed against rabbit synovial collagenase. We demonstrated that ligament (ACL) and tendon (PT) collagenases cross react with this antibody in a double immunodiffusion assay. Protein blots of PT, ACL and MCL collagenases identified one major species (Mr = 45,000) and a minor species (Mr = 50,000) of immunoreactive proteins in all three connective tissues. Differences between control and experimental enzyme levels appear to be due to less collagenase protein being produced by immobilized ligaments.

Animals↗
PubMed1988

Incidence of deep vein thrombosis after major abdominal surgery in Brisbane.

There is some evidence that postoperative deep vein thrombosis (DVT) may be commoner in cool than in warm climates. To determine whether this complication is less common in the subtropical climate of Brisbane than in more temperate locations, the incidence of DVT after major abdominal surgery was assessed by 125I fibrinogen scanning. In order to avoid overestimating the incidence of DVT, abnormal scans were accepted as diagnostic only if the DVT was confirmed by venography or if the abnormality on the scan fulfilled more stringent criteria than have previously been applied. Thirty-six of 152 patients (24 per cent) developed a DVT; this incidence was significantly lower than in one previous study from Melbourne and higher than that found in South-East Asia and East Africa, but was not significantly different from that reported from Sydney, Japan and several centres in North America and Britain. There was no apparent seasonal variation in the incidence of the complication. The geographical variation in incidence of postoperative DVT may have been overestimated in previous reports and may be at least partly due to variations in screening technique.

Adult↗
PubMed1988

Transjugular liver biopsy--an Australian experience.

During the four year period 1983-87 transjugular liver biopsy was performed on 67 patients (M43, F24) aged 17-79 yr (mean 45.6 yr). Standard percutaneous biopsy was contraindicated by coagulation disorders (95%) often with ascites (17%). Biopsies were taken using a specially modified Ross trans-septal needle passed into hepatic veins under fluoroscopic guidance. Hepatic tissue samples were obtained from the initial biopsy in 62 (93%) patients. In 30 consecutive transjugular biopsies a mean area of 38.2 mm2 per section (0.9-100 mm2) was available for histology compared with an area of 15.9 mm2 (9.3-48.8 mm2) in 50 consecutive percutaneous biopsies. Improved techniques of sample washing, sieving and fixation optimised separation of hepatic tissue from blood clot and fibrin. Four patients experienced significant complications but no deaths occurred. Individual diagnoses were changed in 17 patients as a result of biopsy findings. This study confirms the efficacy and relative safety of the transjugular approach in obtaining liver biopsies from patients with contraindications to standard percutaneous techniques.

Adolescent↗
PubMed1988

Topical corticosteroids for skin disorders in infants and children.

Topical corticosteroids are an essential part of the treatment regimen of children with atopic eczema and a number of other inflammatory dermatoses, such as infantile seborrhoeic eczema, pompholyx and contact dermatitis. A special form of treatment, the 'wet wrap technique, has been found to be effective in treating children with acute erythrodermic eczema in an inpatient setting. Therapy usually lasts for 3 to 5 days and is useful as crisis intervention therapy. On the other hand, in some conditions, for example pityriasis alba, perioral eczema or juvenile plantar dermatosis, therapy with these agents is generally not required or may not be useful. It is important to remember that care must be taken when a topical corticosteroid is prescribed in children, since this age group is particularly at risk of developing side effects. Thus, the patient should be monitored closely, and potent agents should be avoided.

Administration, Topical↗
PubMed1988

Collagenase production by rabbit ligaments and tendon.

Three periarticular connective tissues from normal rabbits were examined for collagenolytic activity. Enzyme activity was secreted by cultures of anterior cruciate ligament (ACL), medial collateral ligament (MCL) and patellar tendon (PT). A lag period of six days or more was often observed prior to the detection of active collagenase. We attributed this to the presence of an excess of inhibitor in the early days of culture. We quantitated the amount of enzyme and inhibitor produced in 13 days. The levels of collagenase in the ACL and MCL were comparable. The PT, however, consistently secreted more enzyme than the two periarticular (ACL and MCL) ligaments. The reaction products were analyzed for all three collagenases and compared to those generated by the rabbit skin enzyme. We observed the characteristic TCA and TCB collagen fragments for MCL and PT enzymes. Collagen cleavage by the ACL cultures resulted in a product with a molecular weight intermediate between the alpha 2 chain and the TCA piece. These data suggest that quantitative and qualitative differences exist in the ability of these similar connective tissues to degrade collagen.

Animals↗
PubMed1988

RNA is covalently linked to SV40 large T antigen.

RNA is shown to be covalently linked to the large tumor antigen (TAg) of simian virus 40 (SV40). Proteolytic digestion of TAg, isolated in the presence of ribonuclease inhibitors from SV40 transformed Balb/c mouse cells, generated a specific phosphopeptide of high charge heterogeneity that was strongly retained on DEAE-cellulose in the presence of 7 M urea. Hydrolysis of this peptide with RNAase released the four standard ribonucleotide monophosphates. Analysis of peptide digestion products showed that the RNA is attached to TAg through a phosphodiester linkage between the beta-hydroxyl of a serine and the 5' phosphate of an invariant cytidine residue. The methods applied to SV40 TAg can be applied to other proteins, including cellular oncogene products, to investigate the possibility of covalent protein-RNA interactions.

Antigens, Polyomavirus Transforming↗
PubMed1987

Insulin stimulates secretion of a collagenase inhibitor by Swarm rat chondrosarcoma chondrocytes.

Swarm rat chondrosarcoma chondrocytes produce an inhibitor of collagenase similar to that found in bovine articular chondrocytes and extracts of bovine scapular cartilage. These cells synthesize normal levels of cartilage type proteoglycans when cultured in serum free medium with insulin. Collagen synthesis is also increased when insulin is added to chondrosarcoma chondrocytes. We have demonstrated that insulin stimulates collagenase inhibitor production by these chondrocytes. Enhancement of inhibitory activity occurs over the range of 10 to 1000 ng/ml. A 3.2 fold stimulation was observed at a concentration of 1 microgram/ml. There was a lag period of 24 to 48 hours before the insulin effect became evident. Latent or active collagenase was not detectable under these conditions. These results suggest that the hormone insulin controls the levels of collagen in this tumor by stimulating synthesis of collagen and inhibitors of collagenase.

Animals↗