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Biomedical subjects

R B Marshall

Publications and source records attributed to R B Marshall.

At least 37 records · Page 2Linked to original sources
PubMed1989

Seasonal prevalence of thermophilic Campylobacter infections in dairy cattle and a study of infection of sheep.

A total of 273 rectal swabs from dairy cows were cultured for Campylobacter jejuni/coli. The isolation rate was 17/72 (24%), 33/106 (31%) and 11/95 (12%) during summer, autumn and winter respectively. Approximately half of the isolates were C. jejuni and the other half C. coli. The isolates recovered from dairy cows were typed by bacterial restriction endonuclease DNA analysis (BRENDA) and compared with those of sheep. Seventeen different BRENDA patterns were produced by the isolates from dairy cows and six from 27 isolates of sheep. Of these 21 different BRENDA patterns only two were common to sheep and cattle.

Journal Article↗
PubMed1989

Campylobacter jejuni infection within a laboratory animal production unit.

A conventional laboratory animal production unit in which rats, mice, guineapigs and rabbits were bred in one building and cats maintained in a separate, but adjacent area was examined for the presence of intestinal thermophilic Campylobacter spp. Campylobacter jejuni was recovered from 18.84% of 552 animals. The infection rate was highest amongst the cats (51.7%), with rats being the second most commonly infected (23.2%), whereas only 7.7% of guineapigs and a single rabbit (1%) were positive. Campylobacter-like organisms were cultured from 10% of the mice, but these bacteria failed to grow on subsequent subculturing. By using bacterial restriction endonuclease DNA analysis (BRENDA), a single type of C. jejuni was identified from all isolates recovered from the rats, guineapigs and a rabbit, suggesting a common source of infection. In contrast, there were 5 different BRENDA patterns derived from cat isolates. No isolates of C. jejuni were obtained from humans working within the unit or from animal bedding or the immediate environment, although it was suggested that the organism may have entered and spread within the unit from sawdust.

Animals↗
PubMed1989

The clear-cell variant of uterine epithelioid leiomyoma. An immunohistologic and ultrastructural study.

A case of a rare uterine clear-cell epithelioid leiomyoma is presented, emphasizing immunohistologic and ultrastructural findings. The presence of actin, vimentin, desmin, muscle-specific antigen, and smooth-muscle-specific actin in tumor cells indicates a smooth-muscle origin, confirmed by electron microscopy. Numerous vacuolated mitochondria produced the cytoplasmic "clearing" on light microscopy.

Actins↗
PubMed1988

The relationship between intestinal Campylobacter species isolated from animals and humans as determined by BRENDA.

Intestinal thermophilic Campylobacter species produce stable patterns when subjected to bacterial restriction endonuclease DNA analysis (BRENDA); this technique is therefore of considerable value in epidemiological studies. BRENDA was used to examine thermophilic Campylobacter species from humans, wild and domestic animals. One hundred and ninety-four (61%) of 316 isolates of Campylobacter jejuni from humans had BRENDA patterns which could be matched to those of animal isolates. Poultry appear to be a major source of infection for C. jejuni in humans with nearly half (49.7%) of the human isolates giving patterns which were indistinguishable from those isolated from poultry. A total of 60 BRENDA types were identified from 316 human isolates and 11 of these had the same pattern as those isolated from poultry. One of the three Campylobacter coli BRENDA types recovered from poultry was indistinguishable from a human isolate type. Pigs appear to be only a minor source of C. coli infection for humans in New Zealand. Rats were found to be infected with strains of C. jejuni with BRENDA patterns indistinguishable from those infecting humans, poultry and a horse. None of the 102 isolates of Campylobacter species from wild birds gave BRENDA patterns similar to those of isolates from humans.

Animals↗
PubMed1988

Immature neural elements in immature teratomas. An immunohistochemical and ultrastructural study.

Immature neural tissue pathobiology in teratomas may have important implications for clinical prognosis, nervous system embryology, and neurological oncology. However, immunohistochemical and ultrastructural examinations of these neoplasms have been scarce. The authors examined immunohistochemically the immature neural elements in nine immature teratomas. Using modified peroxidase-antiperoxidase (PAP) immunoperoxidase (IP) techniques, they evaluated the immunoreactivity to glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), neurofilament (NF), chromogranin (CG), and vimentin (VM). All nine teratomas were immunoreactive for both GFAP and NSE, one was reactive for NF, and five (56%) were immunoreactive for vimentin. All cases were nonreactive for chromogranin. In addition, ultrastructural examination (electron microscopic [EM]) was performed on eight of these tumors. By EM examination, both astrocytes and oligodendroglia were identified in varying stages of development. Astrocytes often displayed abundant intermediate filaments. However, primitive undifferentiated cells were also found. Neuronal differentiation included long cell processes with tubules and filaments, vesicles, rare dense-core granules, and synapses. Ependymal differentiation (cilia, microvilli, prominent junctions) was observed in two cases. Pigmented retinal epithelium was seen in one tumor. No ambiguous (hybrid) cells were identified. Cellular interactions usually resembled the relationships found in normal adult brain tissue.

Adolescent↗
PubMed1988

Restriction endonuclease analysis of Leptospira interrogans serovar hardjo isolates from cattle.

The genomes of 253 strains of Leptospira interrogans serovar hardjo were examined by restriction endonuclease analysis of their DNA. The strains had been isolated from cattle at an abattoir (190), milk of agalactic cows (seven) and from aborted bovine fetuses (56). Two distinct genome types, Hardjoprajitno and Hardjobovis, were detected. The majority (91 per cent) of isolates from abattoir cattle were of the Hardjobovis type while most (76 per cent) of the isolates from clinical/pathological material were similar to Hardjoprajitno.

Animals↗
PubMed1987

Malignant mixed müllerian tumors. An ultrastructural and immunohistochemical analysis with histogenetic considerations.

In the female genital tract, malignant mixed müllerian tumors (MMTs) are uncommon neoplasms of uncertain histogenesis. We have examined 11 MMTs by both electron microscopy (EM) and immunoperoxidase techniques (IPX). Eight were of endometrial, two were of ovarian, and one of tubal origins. The IPX analysis included monoclonal antibodies to keratin (k) and vimentin (v) and a polyclonal antibody to myoglobin. Carcinomatous elements were always keratin positive (K+) and were focally positive for vimentin in six tumors. Homologous stromal sarcoma cells were vimentin positive (V+) and in three tumors were focally K+. Ultrastructurally, the epithelial cells were not highly differentiated and the sarcomatous elements generally resembled normal proliferative-phase stromal cells. The epithelial and stromal elements were separated by a thin basal lamina that only rarely and focally had discontinuities. No transitional cellular forms were identified. A definite positive myoglobin reaction was seen in two of the four neoplasms in which rhabdomyoblasts were identified by light microscopy. Myofilaments were identified by electron microscope in three neoplasms.

Aged↗
PubMed1987

The significance of nuclear diameter in the biologic behavior of thyroid carcinomas: a retrospective study of 127 cases.

The relationship between nuclear diameter and biologic behavior was studied in 127 cases of thyroid carcinoma. Using a sonic digitizer coupled to a minicomputer, nuclear diameters of 200 randomly selected cancer cells from each case (hematoxylineosin-stained paraffin sections) projected at X 400 magnification were traced and averaged. A total of 25,400 measurements were made. The nuclear diameters varied from 4.7 to 13.1 micron. By analysis of variance, the nuclear diameters were significantly different (p = 0.0007) among the four types of thyroid cancers, being largest in the undifferentiated cancers (8.7 +/- 0.8 micron) and smallest in the medullary cancers (6.6 +/- 0.1 micron). Nuclear diameter was also significantly correlated with degree of tumor differentiation (p = 0.002), maximal tumor diameter (p = 0.03), mitotic rate (p = 0.002), and 5-year survival (p less than 0.05) for all types of tumors. The correlation between nuclear diameter and disease stage was significant only for undifferentiated cancers (p = 0.04). No significant correlations were seen between nuclear diameter and duration of disease, sex, or age of the patient.

Adolescent↗
PubMed1986

Correlation of female sex steroid hormone receptors with histologic and ultrastructural differentiation in adenocarcinoma of the endometrium.

A series of 43 patients with endometrial adenocarcinoma were evaluated in order to investigate the relationships of the estrogen receptor (ER) and the progesterone receptor (PR) with the histologic and nuclear grades and the ultrastructural differentiation of these tumors. Twenty-six neoplasms were positive (greater than or equal to 10 fmole/mg protein) for both receptors, 1 was positive for the ER only, 9 were ER-PR+, and 7 were ER-PR-. Twenty carcinomas were histologic Grade I, 12 Grade II, and 11 Grade III. Distribution of nuclear grade was 11 Grade I, 18 Grade II, and 14 Grade III. Both histologic and nuclear grades were found to be significantly related to the presence or absence of both the ER and the PR. Several cytoplasmic structures (cilia, primary lysosomes, intracytoplasmic lumens) were highly specific but of low sensitivity for predicting the receptor status of these tumors. To a limited extent, ultrastructural markers were associated with histologic differentiation.

Adenocarcinoma↗
PubMed1986

Endometrial adenocarcinoma. A multiparameter clinicopathologic analysis including the DNA profile and the sex steroid hormone receptors.

With endometrial adenocarcinoma, several factors, such as stage and histologic grade, are well recognized as having prognostic significance. Other variables, e.g., nuclear grade, probably are also important clinically. A preliminary investigation of the prognostic value of the ploidy, cell cycle kinetics, and sex steroid receptor contents of these tumors has been conducted and compared with more conventional prognostic factors such as stage, grades, and depth of invasion. As analyzed by flow cytometry, the proliferative activities of the carcinomas were significantly associated with prognosis. Tumors with lower levels of proliferative activity were related to improved survivals. Two thirds of the carcinomas were diploid; ploidy did not carry prognostic weight in the series. Both the estrogen and progesterone receptor status were related to survival. Patients whose tumors were positive for these receptors had a better prognosis than did those in which the receptors were not present in significant quantities.

Adenocarcinoma↗
PubMed1986

In vitro studies of haemolysis by Leptospira interrogans serovars pomona and ballum.

Washed and unwashed red blood cells (RBC) from young calves, adult cattle, hamsters and humans were incubated with Leptospira interrogans serovars pomona and ballum. Washed cells suspended in saline were always haemolysed while unwashed cells and those which were washed and resuspended in plasma were never haemolysed, despite the presence of large numbers of organisms within the culture supernatant. Pomona produced greater haemolysis of cattle and human RBC than did ballum, but with hamster RBC ballum produced greater haemolysis than did pomona. A group of 6- to 9-month-old cattle infected with pomona showed no signs of clinical disease and RBC taken from them before infection and during the development of antibodies to pomona were haemolysed by pomona only after the cells were washed. Plasma therefore appears to have a protective function. This in vitro protective function of plasma even extended to plasma from young seronegative calves.

Animals↗
PubMed1986

Experimental trials on the use of radioimmunoassay for the detection of leptospiral antigens in urine.

Trials were conducted on the use of the solid phase radioimmunoassay (RIA) to detect leptospires or their antigens in simulated urine samples. The procedure was relatively simple to perform and appeared to be specific in detecting certain numbers of leptospiral organisms or their antigens in experimentally prepared samples. With this technique, it was possible to examine individual or pooled urine samples for the presence of leptospires within half a day. This technique may be of value for the detection of leptospiruric animals if the sensitivity of the technique could be further increased. Suggestions for the improvement of the procedure are discussed.

Animals↗
PubMed1986

Dual infections of red deer (Cervus elaphus) by Leptospira interrogans serovars copenhageni and hardjo.

On a property in the Nelson District, blood and urine samples were taken from red deer (Cervus elaphus) from which low (<1:100) antibody titres to serovar copenhageni and suspected leptospiral abortions had previously been reported. A total of 27 hinds were sampled. Microscopic agglutination test (MAT) titres in sera ranging from 1:32 to 1:128 were found in six animals. Thirteen leptospiral isolations were made from nine of the 27 urine samples. Four of these were typed as copenhageni and nine as hardjo. Two cultures were prepared from each urine sample and hardjo and copenhageni were both isolated from single urine samples from two animals. None of the 27 deer had serum MAT titres at 1:32 or above to copenhageni.

Journal Article↗
PubMed1986

A comparison of serotyping, BRENDA-typing and incompatibility grouping, and toxin testing of haemolytic Escherichia coli isolated from piglets before and after weaning.

Before weaning, some young pigs in a research piggery excreted in their faeces a weakly haemolytic non-enterotoxigenic serotype of Escherichia Coli. After weaning, all of the pigs excreted strongly haemolytic Escherichia coli of known enteropathogenic serotypes (0-138 and 0-139). The 0-138 serotype produced vero cell toxin, whilst the 0-139 serotype elaborated heat labile enterotoxin. Haemolytic enterotoxigenic E. Coli were also recovered from three-week-old unweaned piglets with so-called ;milk scours; and from pigs with post-weaning diarrhoea on two local commercial piggeries. Selected haemolytic isolates were compared using serotyping, bacterial restriction endonuclease DNA analysis (BRENDA) and incompatibility grouping. The three typing methods divided most of the isolates into the same groupings; the exceptions were two isolates with the same BRENDA pattern and incompatibility group, but with different H-serotypes, and eleven isolates with the same serotype and BRENDA pattern but which showed differences in colony compatibility such that they were divided into five subgroups of a single incompatibility type.

Journal Article↗