Biomedical subjects

A M Haase

Publications and source records attributed to A M Haase.

9 recordsLinked to original sources

PubMed1995

Improved detection of Chlamydia trachomatis in endocervical samples by using a new polymerase chain reaction assay.

AIM: To compare the performance of a commercially developed polymerase chain reaction (PCR) assay, Amplicor Chlamydia trachomatis from Roche Molecular Systems, with that of a standard enzyme immunoassay (EIA) system, Chlamydiazyme from Abbott Laboratories, which is currently used throughout New Zealand. METHODS: Cervical swabs were collected from 819 female patients attending the family planning clinic in Christchurch. These swabs were then analysed using the Amplicor and Chlamydiazyme assays. RESULTS: The prevalence of chlamydia infection was 4.2% by the Chlamydiazyme EIA method and 5.3% with the Amplicor PCR assay. In 20 cases, where the results from the two assays were discordant, the conflict was 'resolved' by using a third assay which detects a separate region of the chlamydia genome. This gave an overall prevalence of 5.8% of confirmed infections in this group. The Amplicor PCR assay detected 29.4% more cases than the usual EIA method. CONCLUSIONS: This study demonstrates that Amplicor PCR assay allows improved identification of C trachomatis infections in a population with a relatively low prevalence of infection. The Amplicor PCR assay detects a significant number of additional infections and should be considered for routine use. As the PCR assay is more expensive a shift in the price/payment structure may be required before this assay comes into widespread use. However, the reduced morbidity resulting from the detection and treatment of otherwise unrecognised cases should also be considered in any cost benefit analysis.

Adult↗

PubMed1994

Clonal diversity of Streptococcus pyogenes within some M-types revealed by multilocus enzyme electrophoresis.

Twenty-two reference isolates and 30 local isolates of group A Streptococci were classified into 36 electrophoretic types (ET) on the basis of allozyme variation at 27 enzyme loci. Local isolates were characterized by a high frequency of M-non typable strains. M-type and ET were more closely associated in local isolates from an endemically-infected population; nevertheless, amongst the local isolates there were also strains of the same ET type with different M-types. A possible explanation is that genetic exchange between strains may introduce different M-types into strains of defined ET when these are exposed to strong selection in the presence of heavy loads of infection. In contrast to the reported clustering of strains associated with toxic shock-like syndrome into two closely related ET clones, we found no relationship of ET phenotype to acute poststreptococcal glomerulonephritis or rheumatic fever.

Alleles↗

PubMed1994

Evidence for effect of random genetic drift on G+C content after lateral transfer of fucose pathway genes to Escherichia coli K-12.

The cps cluster of Escherichia coli K-12 comprises genes involved in synthesis of capsular polysaccharide colanic acid. Part of the E. coli K-12 cps region has been cloned and sequenced and compared to its Salmonella enterica LT2 counterpart. The cps genes from the two organisms are homologous; in the case of the LT2 genes, with G+C content of 0.61 and codons characteristic of high G+C species, it seems clear that they have been acquired relatively recently by lateral transfer from a high G+C species. The K-12 form of these cps genes is closely related to those of LT2 so must derive from the same high G+C species, but it appears to have transferred much earlier such that random genetic drift has brought P3 (the corrected G+C content of codon base 3) down from 0.77 to 0.64, more than halfway to the E. coli average of 0.57. We estimate, using an equation developed by Sueoka, that the lateral transfer to E. coli took place approximately 45 million years ago. This is the first report we are aware of demonstrating the expected adjustment of P3 after lateral transfer between species with different G+C content DNA.

Amino Acid Sequence↗

PubMed1993

Glycosyl transferases of O-antigen biosynthesis in Salmonella enterica: identification and characterization of transferase genes of groups B, C2, and E1.

In Salmonella enterica, there is a great variety of O antigens, each consisting of a short oligosaccharide (the repeating unit) repeated many times. The O antigens differ in their sugar composition and glycosidic linkages. The genetic determinants of the O antigen are located in an rfb gene cluster, and some, including those of S. enterica O serogroups B, C2, and E1, have been cloned and sequenced. In this study of the glycosyltransferases which form the glycosidic linkages, we identify and characterize the four mannosyl and three rhamnosyl transferase genes of the three rfb gene clusters.

Carbohydrate Sequence↗

PubMed1993

Variation of the rfb gene clusters in Salmonella enterica.

In order to explore the genetic variation of O antigens of Salmonella enterica, we surveyed 164 strains (132 serovars) belonging to 45 serogroups, using 25 mostly single-gene rfb DNA probes for colony hybridization. The results revealed that strains within a serogroup have very similar or identical rfb genes. At least three of the four rhamnose genes were detected in all 17 serogroups reported to contain rhamnose, and one or more were detected in three others. The likelihood of being detected decreased in the order rfbB, rfbC, rfbA, and rfbD, which is the map order, suggesting a gradient of divergence. Mannose pathway genes were much less conserved, and of 27 groups reported to contain mannose or mannose derivatives colitose or fucose, only 9 hybridized to the rfbM and rfbK probes. Dideoxyhexose genes were found only in groups reported to contain dideoxyhexoses. Group D2, which had not been studied previously, appears to resemble group D1, with the substitution of one gene from group E1 to give a change in one linkage. In contrast to sugar pathway genes, sugar transferase genes did not in general hybridize to strains of other groups outside the closely related groups A, B, and D, with the exception of the galactose transferase gene also shared by groups C2, C3, and all E groups.

Bacterial Proteins↗

PubMed1991

Polymorphism of HLA-DRw52-associated DRB1 genes as defined by sequence-specific oligonucleotide probe hybridization and sequencing.

We have used group-specific DNA amplification and sequence-specific oligonucleotide probe (SSOP) hybridization to study DRB1 sequence polymorphisms associated with DR3, DRw11(5), DRw12(5), DRw13(w6), DRw14(w6) and DRw8 alleles. Group-specific amplification of DRw52-associated DRB1 alleles was achieved using a 5' amplification primer designed to hybridize with a first hypervariable region (HVR) sequence common to all known alleles in this group, together with a 3' intron primer. Prospective SSOP typing of DR3, DRw11, DRw12, DRw13, DRw14 and DRw8 alleles was performed in 318 individuals, including 124 patients, 46 family members and 148 unrelated marrow donors. Among the 395 DRw52-associated DRB1 alleles tested in our study, a subtype corresponding to the previously defined alleles DRB1*0301-2 (DR3), DRB1*1101-4 (DR5), DRB1*1201-2 (DR5), DRB1*1301-5 (DRw6), DRB1*1401-2 and 1404 (DRw6), and DRB1*0801-4 (DRw8) could be assigned in all but 6 individuals (1.9%) tested. In addition to the 22 known alleles, we identified two new DRw6-associated alleles, DRB1*13.MW(1) and DRB1*14.GB(1). DRB1*13.MW typed serologically as DRw13 and was identical to DRB1*1301 except at codon 71 where AGG encodes arginine instead of GAG encoding glutamic acid. DRB1*14.GB represents a DRB1*1402 variant whose sequence at codon 86 encodes valine (GTG) instead of glycine (GGT). These results demonstrate that SSOP methods represent an efficient and precise approach for typing DRB1 alleles and for identifying potential novel variants previously unrecognized by conventional typing methods.

Alleles↗

PubMed1978

Measurement of work satisfaction among health professionals.

This paper describes a three-year research project that investigates the concept of occupational satisfaction of health professionals and suggests a method of measuring their level of occupational satisfaction. Additionally, the research examines factors defining occupational satisfaction important to health professionals. This process involves the development of a scale that measures the relative importance of various components of satisfaction, attitudes toward these components, and a weighted Index of Work Satisfaction. The methodology utilized in the development of this scale in an institutional setting with a sample of nurses is described, along with the transfer of this scale to three categories of health professionals involved in an outpatient setting. Responses from the physicians, nurses, and support staff in the ambulatory setting and responses from the hospital nurses indicate that the scale does measure occupational satisfaction of health professionals both in institutional and noninstitutional settings. Finally, statistical analysis of the original scale is reported and a revised scale is suggested for wider use.

Group Practice↗

PubMedDate not supplied

Empathy training as the major thrust of a staff development program.

The purpose of the study was to develop a human-relations-modeled staff development program and obtain an objective measure of the level of empathy of registered nurses who practiced in an acute- and chronic-care hospital. The short-term human-relations-modeled staff development program was designed specifically to assist nurses who scored low in empathy to increase their abilities to perceive and respond with greater empathy. The study indicated that all nurses tested possessed an extremely low level of empathy, that the staff development program significantly raised their levels of empathy, but that more training was needed to enable all or the majority of subjects to reach at least the minimal facilitative level necessary to help another person successfully.

Adult↗

PubMedDate not supplied

Nurses' satisfaction with their work situation.

Although job satisfaction is related to performance within the work setting, precise definitions and methods of measuring satisfaction are lacking, especially in medical settings. This article describes a two-year research project that investigated the concept of occupational satisfaction and methods of measuring this concept among in-and outpatient nurses. The Index of Work Satisfaction, a scale that measures relative importance of various components of satisfaction and attitudes toward the components, as well as an overall summary score, was developed. Methodology of the scale development, utilizing hospital nurses and nurses involved in a private group-practice setting, is described. Analysis of the responses from the nurses indicated that the scale measured occupational satifaction of nurses in both settings.

Attitude of Health Personnel↗