Biomedical subjects

H Norris

Publications and source records attributed to H Norris.

At least 19 recordsLinked to original sources

PubMed1999

Chromosome translocations in couples with in-vitro fertilization implantation failure.

Recurrent miscarriage is known to be associated with parental chromosomal abnormalities, particularly balanced reciprocal and Robertsonian translocations. The aim of this study was to test the hypothesis that couples with in-vitro fertilization (IVF) implantation failure, like those with recurrent miscarriage, have a higher than expected prevalence of translocations which may impact on pregnancy outcome. Patients who previously had at least 10 embryos transferred without achieving clinical pregnancy were evaluated for chromosome abnormalities as part of screening investigations for implantation failure. Recurrent miscarriage patients with a history of at least three consecutive first-trimester abortions were also tested. Results were compared to reports of infertility patients presenting for treatment and population neonatal screening programmes. Chromosomal abnormalities overall were detected in 13/514 individuals with implantation failure (2.5%), and 15/319 individuals with recurrent miscarriage (4. 7%). Translocations (reciprocal and Robertsonian) were found in 7/514 individuals (1.4%) and 7/219 couples (3.2%) with implantation failure (P < 0.0005 compared with infertile controls and P < 0.0001 compared with screened neonates). Translocations were found in 13/319 individuals (4.1%) and 12/130 couples (9.2%) with recurrent miscarriage. Balanced parental translocations may be implicated in the pathogenesis of IVF-implantation failure. Genetic evaluation should be considered as part of the investigation of these patients.

Adult↗

PubMed1998

Comparison of a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-t etrazolium hydroxide (XTT) colorimetric method with the standardized National Committee for Clinical Laboratory Standards method of testing clinical yeast isolates for susceptibility to antifungal agents.

MICs for clinical Candida and Cryptococcus isolates were determined by a method incorporating the colorimetric indicator 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl] -2H-tetrazolium hydroxide (XTT), and the results were compared with MICs obtained by the National Committee for Clinical Laboratory Standards approved standard method (M27-A). One hundred percent of all isolates demonstrated agreement within 2 dilutions between the MICs of amphotericin B, fluconazole, itraconazole, ketoconazole, and flucytosine obtained by the two methods. These data suggest that an XTT-based method could provide a useful means for the determination of antifungal susceptibility of yeasts.

Amphotericin B↗

PubMed1997

Drug calculation competencies of graduate nurses.

This study describes the analysis of the mathematical ability of 220 registered nurses (RNs) from six Victorian universities who applied for a graduate year program at St Vincent's Hospital, Melbourne. Each applicant completed a drug calculation competency test (DCCT) which required them to calculate 11 drug dosages commonly performed by RNs in clinical practice. The results revealed that 58 percent (n = 127) of the 220 applicants were not able to accurately calculate all 11 drug dosages. The results also demonstrated significant differences between applicants from respective universities. The findings suggest that there are fundamental problems with the mathematical competencies of this group of newly graduated nurses. The results may also support the assertion that the educational preparation of these nurses at the undergraduate level could be enhanced in some universities and does not appear to adequately prepare nurses to perform basic drug calculations which are frequently required in the acute setting.

Clinical Competence↗

PubMed1995

Effects of aging and castration on plasminogen activator and metalloprotease activities in the rat prostate complex.

Pathology of the prostate gland in rats and humans is associated with aging. Our objective was to examine the effects of aging on the activities of plasminogen activators and metalloproteases in the prostatic complex of rats. Plasminogen activator activities (very low in the anterior, lateral, and dorsal lobes, in contrast to higher activities in the ventral lobe of 4-month-old adult rats) increased with aging in the dorsal and anterior prostate lobes of 31-month-old rats; these activities also increased in the dorsal and lateral lobes upon castration of 18-month-old rats. The plasminogen activator activities in the ventral lobe did not increase with aging to 18 months but did increase 3-5-fold after castration of either young or old rats. Metalloprotease activities of 70 and 76 kDa were observed in the anterior and lateral lobes of 4 month untreated adult rats, whereas the dorsal lobe showed MP of 70 and 92 kDa. Castration of young adult rats increased activities of all three molecular forms of metalloprotease in these three lobes. Increased expression of metalloprotease activities was also found with aging to 31 months in the anterior, lateral, and dorsal lobes. However, changes in metalloprotease activities associated with age were most striking in the lateral lobe and included activities of 52, 55, 81, 93, 113, and 117 kDa at 18 months of age. Castration for 30 days at this age resulted in a decline in the 52, 55, 113, and 117 kDa activities and an increase in activities of the 70, 81, and 93 kDa forms. These latter metalloprotease activities were also increased in the dorsal lobe after castration. Our results suggest that some metalloprotease activities increased in the dorsal lobe after castration. Our results suggest that some metalloprotease activities increased in the lateral lobe with age possibly result from an increased accumulation of secretory proteins (i.e., 52, 55, 113, and 117 kDa), whereas the 70, 81, and 93 kDa metalloprotease activities may be related to possible prostatitis and/or involved in changes in tissue organization. The increased expression of metalloprotease activities in the lateral and dorsal prostate lobes with aging, and castration upon aging, may be indicative of altered hormonal regulation of these proteases in these lobes.

Aging↗

PubMed1993

Spinal fluid cells and protein in amyotrophic lateral sclerosis.

The cerebrospinal fluid total protein in 385 cases of sporadic amyotrophic lateral sclerosis showed no relationship to survival, but it was related to survival time in 34 cases of familial amyotrophic lateral sclerosis. Infrequent and mild pleocytosis, and oligoclonal bands seemed to have no clinical significance in well established cases of amyotrophic lateral sclerosis.

Aged↗

PubMed1993

Onset, natural history and outcome in idiopathic adult motor neuron disease.

Cases of adult-onset idiopathic motor neuron disease (MND) identified from January 1970 through December 1986 were studied in a defined area of California. The patients were followed prospectively throughout the illness in 99% of cases. Among 708 cases aged 25-74 years at onset, the most common type (86%) was typical, sporadic amyotrophic lateral sclerosis (SporALS). The risk of bulbar onset and shorter survival times increased with age in both men and women. About 4%, mainly younger men, experienced unusually long courses with milder paralysis, but could not be identified early in the illness. They probably represent one extreme of the ALS spectrum rather than a distinct subtype. Familial ALS (FamALS) was diagnosed in 7%. It developed earlier in life but ran a slightly longer course, which suggests a different disease process. Overall there was a statistically significant predominance of males, especially in 17 cases (2%) of progressive muscular atrophy (PMA). There were 26 cases (4%) classified as primary lateral sclerosis (PLS). Progressive bulbar palsy was not found; that diagnosis usually denotes merely the bulbar onset of ALS.

Adult↗

PubMed1993

Gelatinolytic and caseinolytic proteinase activities in human prostatic secretions.

Seminal fluid contains a number of proteinase activities, many of which are secreted by the prostate gland. Our objective was to determine proteinase activities in human prostatic secretions which can degrade gelatin and/or casein. Prostatic secretions were collected by prostate massage from men with benign prostatic hyperplasia prior to surgery to relieve obstruction. Significant proteinase activities towards gelatin of about 81, 86, 94, 111, 115 and 163 Kd as well as less active forms of 23, 36, 38, 132, 137, and 148 Kd were detected using protein substrate-polyacrylamide gel zymography. In addition, Ca2+ stimulated activities of approximately 64, 66, 71 and 76 Kd; however, EDTA and EGTA inhibited all activities but the 23, 36 and 38 Kd forms (these were inhibited by benzamidine and epsilon-amino caproic acid). This suggests that the gelatinolytic activities of 64 Kd and greater were metalloproteinases and those of 23, 36, and 38 Kd were serine proteinases. Significant caseinolytic activities of 22, 25, 35, 37, 57, 90, 96, 102 and 116 Kd were found as well as several less active forms and a 12 Kd activity stimulated by Ca2+. Caseinolytic activities of 12, 14, 16, 96, 102, 116, and 126 Kd were inhibited by EDTA and EGTA indicating they are metalloproteinases. The 35, 37, 57 and 58 Kd caseinolytic activities were inhibited by benzamidine, and the 57 and 58 Kd forms by epsilon-aminocaproic acid suggesting they were serine proteinases. There was considerable variability among individuals in the molecular forms of proteinase activity expressed as well as the level of their activity. A significant decrease in the frequency of expression of the 132 Kd gelatinolytic activity was found in secretions from men with atypia or adenocarcinoma, as compared with men with benign prostatic hyperplasia alone. Our results show that human prostatic secretion contains a variety of proteinase activities. The expression of the 132 Kd gelatinolytic activity could prove useful in further evaluation of neoplastic prostatic disease.

Caseins↗

PubMed1992