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Biomedical subjects

J B Anderson

Publications and source records attributed to J B Anderson.

At least 55 records · Page 3Linked to original sources
PubMed1994

Matrix metalloproteinase 9 expression in primary human prostatic adenocarcinoma and benign prostatic hyperplasia.

Matrix metalloproteinase (MMP) expression was investigated in patients with prostatic adenocarcinoma and benign prostatic hyperplasia (BPH). Forty-one men were studied: 26 had histologically proven prostate cancer, with 14 (54%) showing metastatic disease; 15 patients had BPH. Prostatic tissue was obtained from transurethral resection and needle core biopsies; gelatinolytic activity was determined by zymography. Seven gelatinolytic bands were detected, with molecular weights ranging from > 100 kilodalton (kDa) to 29 kDa. Nine of 14 patients (64%) with skeletal metastases had 92 kDa activity, present in only two of 12 patients (17%) with a negative bone scan, and absent in BPH. The 92 kDa gelatinolytic activity was expressed in 73% of aneuploid tumours compared with 20% of diploid tumours. A 97 kDa gelatinase was expressed in 80% of BPH samples and 23% of carcinoma patients. Enzyme bands of 72, 66 and 45 kDa were equally expressed in malignant tissue, irrespective of metastatic status, but were expressed in fewer BPH patients. The 97, 92, 66 and 45 kDa enzymes were identified as being pro-MMP-9 sequences by Western blotting, using a specific antibody directed against the pro sequence of the mature protein. MMP activity appeared to be increased in malignant prostatic tissue compared with BPH. Pro-MMP-9, in its 92 kDa form, was shown to be exclusively expressed by malignant prostatic tissue, and in particular by tumours that exhibited the aggressive and metastatic phenotype.

Adenocarcinoma↗
PubMed1993

Meiotic behavior and linkage relationships in the secondarily homothallic fungus Agaricus bisporus.

This study followed the transmission of 64 segregating genetic markers to 52 haploid offspring, obtained from both homokaryotic and heterokaryotic meiospores, of a cross (AG 93b) of Agaricus bisporus, the commonly cultivated "button mushroom." The electrophoretic karyotypes of the AG 93b component nuclei were determined concurrently (n = 13). Eleven distinct linkage groups were identified by two-point analysis. DNA-DNA hybridization showed that nine of these corresponded to unique chromosome-sized DNAs. Two other chromosomal DNAs were marked with nonsegregating markers, including the rDNA repeat. Two remaining chromosomes remained unmarked but hybridized to repeated-sequence probes. Cross 93b had an essentially conventional meiosis in which both independent assortment and joint segregation of markers occurred, but in which crossing over was infrequent over much of the mapped genome. The 48 homokaryotic spore-offspring had overall crossover frequencies that were similar to, but possibly slightly less than, those of three homokaryon constituents of heterokaryotic spore-offspring. These daa provide support for our earlier cytogenetic model of sporogenesis in A. bisporus, that explains why heterokaryotic spore-offspring usually appear to exhibit no recombination. No evidence favoring an alternative, mitotic model of sporogenesis was found. The resulting genetic map appears to survey the genome extensively and for the first time permits localization of loci determining economically important traits in this fungal crop species. Large differences in the vigor of homokaryotic offspring were correlated with the inheritance of certain chromosome segments and were also often associated with significant departures from Mendelian segregation ratios.

Agaricus↗
PubMed1993

Localization of the Mating Type Gene in Agaricus bisporus.

The cultivated mushroom Agaricus bisporus is secondarily homothallic. Most basidia produce two basidiospores, each of which receives two of the four postmeiotic nuclei. Usually, the two packaged nuclei carry compatible mating types. Previous studies suggested that there may be only a single mating type locus in A. bisporus. In this study, we determined whether the mating type segregated as a single Mendelian determinant in a cross marked with 64 segregating molecular markers. To score mating types, each of the 52 homokaryotic offspring from this cross was paired with each of the two progenitor homokaryons. Compatible matings were identified by the formation of genetically stable heterokaryons which were verified by assay of restriction fragment length polymorphisms (RFLPs). Data for screening mycelial interactions on petri plates as well as fruit body formation were compared with the RFLP results. Mating types of 43 of the 52 homokaryotic offspring were determined on the basis of RFLP analysis. Our results indicate (i) there is a segregating mating type gene in A. bisporus, (ii) this mating type gene is on the largest linkage group (chromosome I), (iii) mycelial interactions on petri plates were associated with heterokaryon formation under selected conditions, (iv) fruit body formation was dependent upon the mating type gene, and (v) compatible mating types may not always be sufficient for fruiting.

Journal Article↗
PubMed1992

Circulating prostate specific antigen-positive cells correlate with metastatic prostate cancer.

Analytical flow cytometry was used to study circulating prostate specific antigen (PSA)-positive cells in 40 consecutive patients with newly diagnosed, untreated prostate cancer; 25 patients (63%) had metastatic disease confirmed by a positive bone scan. Cell suspensions were prepared for each patient from both the primary tumour and peripheral blood samples. The cells were stained with a monoclonal antibody against PSA, and analysed by flow cytometry; PSA-positive cells were sorted according to their immunofluorescence and light scatter properties. The cellular deoxyribonucleic acid (DNA) content of each specimen was also analysed to establish ploidy status. PSA-positive cells were detected in the peripheral blood of 33 patients (83%). The presence of these cells in the circulation showed a higher degree of sensitivity and specificity in predicting positive bone scans than did serum PSA levels. Circulating PSA-positive cells may represent either a subpopulation of tumour cells with distinct metastatic properties or, alternatively, host immunocytes which take up PSA in an active or passive manner.

Aged↗
PubMed1991

Postoperative retention of urine: a prospective urodynamic study.

OBJECTIVE: To investigate the cause of post-operative retention of urine in elderly men. DESIGN: Prospective study. SETTING: Northern General Hospital, Sheffield. PATIENTS: 32 consecutive men (median age 73, range 55-85) referred to the urology department who were unable to pass urine either within 48 hours after operation and required catheterisation (23) or after removal of a catheter inserted at the initial operation (nine). INTERVENTION: Intermittent self catheterisation. MAIN OUTCOME MEASURES: Urological investigation by medium fill and voiding cystometry within four weeks after operation, and minimum follow up three months thereafter. RESULTS: 6 patients resumed normal voiding before urodynamic assessment, three proceeded straight to prostatectomy, and one was unfit for self catheterisation. Of 22 men who underwent urodynamic investigation, only five had bladder outflow obstruction, who subsequently had successful prostatectomy; 15 showed either a low pressure-low flow system (seven) or complete detrusor failure (eight) and two showed pelvic parasympathetic nerve damage. With intermittent self catheterisation spontaneous voiding returned in all but one man within a median of 8 weeks (range 6-32 weeks). Recovery of bladder function took significantly longer in men with detrusor failure than in those with an underactive bladder (median 10 weeks (range 6-32 weeks) v median 8 weeks (range 6-8 weeks); p = 0.05). Three months later all patients had re-established their own normal voiding pattern with minimal residual urine on ultrasonography and satisfactory flow rates. CONCLUSIONS: Postoperative urinary retention in elderly men is not an indication for prostatectomy; a normal pattern of micturition can be re-established by intermittent self catheterisation in most men.

Aged↗
PubMed1990

Mitochondrial genetics in a natural population of the plant pathogen armillaria.

Transmission and propagation of mitochondrial genotypes in fungi have not been previously investigated in the field. This study examined the distribution of nuclear and mitochondrial genotypes in a natural, local population of the fungal (Basidiomycetes) root-rot pathogen, Armillaria. Six vegetative clones, ranging in size up to 635 m, were identified on the basis of mating-type alleles. Mitochondrial DNA (mtDNA) restriction fragment patterns indicated that each vegetative clone has one, unique mtDNA type. However, as in other basidiomycetous fungi, biparental transmission of mitochondria following laboratory matings of sexually compatible haploid isolates of Armillaria resulted in a uniformly diploid mycelium that was a mosaic for both parental mitochondrial types. Therefore, either matings between monosporous, haploid isolates are uncommon in nature, or when mating does occur, cytoplasmic markers of one partner predominate during subsequent vegetative growth.

Basidiomycota↗
PubMed1990

Isolation of chloroplastic phosphoglycerate kinase : kinetics of the two-enzyme phosphoglycerate kinase/glyceraldehyde-3-phosphate dehydrogenase couple.

We report here a method for the isolation of high specific activity phosphoglycerate kinase (EC 2.7.2.3) from chloroplasts. The enzyme has been purified over 200-fold from pea (Pisum sativum L.) stromal extracts to apparent homogeneity with 23% recovery. Negative cooperativity is observed with the two enzyme phosphoglycerate kinase/glyceraldehyde-3-P dehydrogenase (EC 1.2.1.13) couple restored from the purified enzymes when NADPH is the reducing pyridine nucleotide, consistent with earlier results obtained with crude chloroplastic extracts (J Macioszek, LE Anderson [1987] Biochim Biophys Acta 892: 185-190). Michaelis Menten kinetics are observed when 3-phosphoglycerate is held constant and phosphoglycerate kinase is varied, which suggests that phosphoglycerate kinase-bound 1,3-bisphosphoglycerate may be the preferred substrate for glyceraldehyde-3-P dehydrogenase in the chloroplast.

Journal Article↗
PubMed1989

Inheritance of restriction fragment length polymorphisms in Agaricus brunnescens.

The cultivated mushroom, Agaricus brunnescens, is secondarily homothallic; most basidia produce only two basidiospores, each of which receives two of the four post meiotic nuclei. The segregation of restriction fragment length polymorphisms (RFLPs) detected by four plasmid probes carrying single-copy nuclear DNA of Agaricus was followed in seven parental strains including commercial, wild-collected, and artificially synthesized heterokaryons. Of a total of 367 single-spore progeny examined, 351 (95.6%) were heteroallelic at all RFLP loci heteroallelic in the respective parents. Of the 16 segregant isolates, ten (2.7% of the total) were homoallelic at all segregating loci assayed, suggesting that these isolates were most probably derived from rare spores that had received only a single postmeiotic nucleus. Some of these ten isolates had recombinant genotypes. Only five isolates (1.4% of the total) showed homoallelism at one of the loci heteroallelic in the parent, while remaining heteroallelic at other loci. These five genotypes suggest that a crossover had occurred between a marker locus and its respective centromere. Taken together, the results suggest that meiosis in A. brunnescens is accompanied by low levels of recombination and that nonsister nuclei are preferentially incorporated into basidiospores after meiosis II.

Agaricales↗
PubMed1989

The enigma of interstitial cystitis--an autoimmune disease?

Interstitial cystitis (IC) is characterised by recurrent inflammation and destruction of bladder tissue without obvious cause. To determine whether this self-perpetuating disease is the result of an autoimmune disorder, we studied 26 patients with IC of mean duration 5 years and compared the results with those of a control group of similar age and sex with other urological complaints. We performed a standard autoimmune profile and looked for specific antibodies to normal human bladder in the serum, using an indirect immunofluorescence technique. Deep bladder biopsies were examined by conventional histology and cryostat sections were studied with peroxidase-conjugated anti-human antibodies in a search for immunoglobulin deposition within the bladder. Seventeen of 26 patients with IC (65%) and 5 of 14 controls (36%) demonstrated non-organ-specific antibodies; 40% of those with IC had anti-nuclear antibodies; 18 IC patients (75%) and 4 of 10 controls (40%) had anti-bladder antibodies present in the serum, but 5 healthy volunteers showed no such antibody activity. There was no statistically significant difference between the two groups for either type of antibody (Fisher's exact test). Only 5 of 17 patients with IC (29%) showed immunoglobulin deposition in the bladder epithelium, a similar proportion to controls (38%); 4 of these 5 had circulating anti-bladder antibodies present in the serum. Although IC patients demonstrated a non-specific increase in antibody formation, this was not significantly different from a similar group of other urological patients. The lack of specificity makes this immunological response more likely to be a secondary phenomenon associated with inflammatory damage to the bladder rather than the primary cause of the disease.

Adult↗
PubMed1988

Testicular torsion in Bristol: a 25-year review.

To identify changes in incidence, presentation, management and outcome, 670 patients with torsion of the spermatic cord presenting in Bristol between 1960 and 1984 have been reviewed. Among the susceptible population of 150,000, the annual incidence of torsion has increased fourfold from 11.2 cases between 1960 and 1964 to 42.8 cases between 1980 and 1984. Throughout this period greater than 90 per cent of patients have been managed by general surgeons. Patients aged between 12-18 years comprised 62 per cent but 20 per cent were 21 years or older. Torsion was commoner in the cold months, 24 per cent of cases occurring during December and January (chi 2 = 30.26, P less than 0.01). When acute torsion was relieved within 12 h of the onset of symptoms only 4 per cent of affected testes were considered non-viable, but beyond this time 75 per cent of patients received orchidectomy. Overall, 238 of 624 (38 per cent) acutely twisted testes were found to be infarcted at operation, and a further 35 patients (6 per cent) had marked testicular atrophy on review 3 months later. The testicular salvage rate has steadily improved from 45 per cent in the years 1960-64 to 67 per cent in 1980-84. Much of the increased incidence of testicular torsion is likely to reflect a greater awareness of the condition by general practitioners. It has been more than matched by an improvement in testicular salvage rate because of earlier referral.

Age Factors↗
PubMed1988

Crosses among Homokaryons from Commercial and Wild-Collected Strains of the Mushroom Agaricus brunnescens (= A. bisporus).

A new technique for the production of hybrid strains of the cultivated mushroom Agaricus brunnescens is described. Homokaryons were recovered from regenerated protoplasts obtained from several heterokaryotic strains. A total of 16 novel hybrids were produced in 63 attempted crosses between paired homokaryons. Recovery of both homokaryons and hybrids was verified by analysis of restriction fragment length polymorphisms. Three of four hybrids fruited in small-scale tests, further confirming that the isolates were true hybrids. Colony morphology alone was found to be a poor indicator of hybrid status. In two instances, three homokaryons crossed successfully in all combinations, suggesting that there are at least three alleles at the putative mating-type locus. Crosses between homokaryons from commercial and wild-collected isolates indicated that these strains belong to the same biological species.

Journal Article↗
PubMed1987

Fine-needle aspiration biopsy and the diagnosis of thyroid cancer.

Conventional criteria for the evaluation of thyroid nodules are inaccurate in identifying the small proportion of malignant neoplasms. The diagnostic accuracy of fine-needle aspiration biopsy (FNAB) for cytology was therefore assessed in 562 patients with nodular thyroid disease, 373 of whom (66.4 per cent) had histological confirmation of the cytological diagnosis. Sixty-one aspiration biopsies were positive for malignancy, and the diagnosis was confirmed histologically in 59 of these (96.7 per cent). Thus, there were two false positive cytology results among 310 patients with proven benign disease (0.6 per cent). Four of sixty-three patients with proven carcinoma had a benign cytological diagnosis, a false negative rate of 6.3 per cent. In 57 of the 59 malignancies (96.6 per cent) correctly diagnosed by FNAB the histological type of tumour was successfully identified. Overall 367 of 373 patients received correct cytological discrimination between benign and malignant nodules, an overall accuracy of 98.4 per cent for FNAB. The sensitivity of the test was 93.7 per cent and the specificity 99.4 per cent. Besides being safe, cost-effective and reliable, FNAB directs the appropriate selection of patients for surgery and enables the correct operation to be performed for each type of tumour.

Adolescent↗