Biomedical subjects
Publications and source records attributed to J S Armstrong.
3,4-Methylenedioxymetamphetamine ("ecstasy") has previously been reported to cause an acute hepatitis that may progress to liver failure. We present the first recorded case of ecstasy-induced accelerated hepatic fibrosis.
Paired serum and cerebrospinal fluid (CSF) samples from 10 AIDS patients with and 10 without AIDS dementia complex (ADC) were studied, in an attempt to uncover ADC-associated variation in V3 sequences. Sequences were obtained from four of the patients with and eight of those without ADC. Comparison of the sequences using a resampling technique revealed a significant ADC-associated difference occurring at several amino acid positions. Results from serum and CSF sequences were comparable. These differences may indicate that the virus found in ADC and that in non-ADC patients have different biological properties. Comparison of serum versus CSF sequences within samples from both ADC and non-ADC patients, using the same resampling technique, revealed no clear distinctions. In some patients, the sequence populations in serum and CSF were completely distinct, while in others, there was no difference in distribution. These patterns were not associated with ADC.
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SIMPLE34 is an improved and enhanced version of SIMPLE for Vax and SunOS systems. It now provides a length-independent measure of the overall level of tri- and tetranucleotide motif clustering within nucleotide sequences and its significant deviation from random expectation. It now also provides information on tri- and tetranucleotide motifs showing higher levels of clustering than would be expected in random sequences. Sequence simplicity of test sequences can be judged with respect to random sequences generated on the basis of base composition, positional base composition or doublet frequency. These options can be used to investigate factors resulting in sequence simplicity.
Fifteen hamartomas of the breast have been studied by dissecting microscopy of thick sections at a depth of 1.0 to 2.5 mm, and by conventional 5 microns deep sections. This combined approach has revealed six distinctive features, three in the parenchymal structure and three in the connective tissue components. Ducts (invariably of penetrating or arcuate configuration) and discrete lobules, neither of which are seen in lesions accepted as fibroadenomas, were invariably found. In one-third of hamartomas, up to 10% of the surface area was occupied by Herãti-style nodules composed of concentric rings of epithelium. In the hyaline interlobular connective tissue characteristic drifts of caraway seed-like fibrocytes, encasement of adipocytes by hyaline collagen, or spider-naevus vascular abnormalities were found in approximately half of the mammary hamartomas when examined in thick sections. Hitherto the positive diagnosis of hamartomas of the breast has relied on a combined clinical, radiological and pathological assessment. We suggest that the additional features described here, taken in conjunction with those already known, may facilitate the recognition of mammary hamartomas by histopathological examination alone.
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In the first year of screening in Avon, 93 malignant lesions were detected of which one-half were impalpable. Of the impalpable lesions, one-half were in situ or showed areas of microinvasion only. One-fifth of the malignant lesions were invasive tumours of special histological type which are known to carry a good prognosis even when not detected by screening. One-quarter of the lesions had clinical or pathological features which would be expected to confer a poor prognosis. Only 16 invasive ductal carcinomas measuring 1 cm or less in diameter were detected--a small proportion of the total number of malignant lesions. Although these early figures suggest that the effect of screening on mortality from breast cancer may be small, continued high-quality screening and careful detailed analysis are essential to determine the effect of screening on the mortality from breast cancer and the effect on the population as a whole.
During the first 2 years (July 1989 to July 1991) of the Avon Breast Screening Service, fine-wire localization biopsy was indicated in 213 impalpable breast lesions. A total of 144 lesions were benign and 69 malignant. Only four of 213 lesions (1.9 per cent) were not excised at the first localization. Factors influencing reoperation in the 69 patients with malignant impalpable lesions were examined. There was a significant association (P < 0.001) between parenchymal disturbances on mammography and invasive carcinoma, and between non-invasive carcinoma and microcalcification (P < 0.001). In 31 patients the localization biopsy was the only surgical procedure. Thirty-eight patients required further surgery: 12 underwent further local excision and 26 mastectomy. Reoperation was more frequent in patients with calcification than in those with parenchymal disturbance (P < 0.001). The most frequent indications for mastectomy were inadequate excision of widespread comedo ductal carcinoma in situ or invasive ductal carcinoma combined with extensive ductal carcinoma in situ. Fine-wire localization biopsy was a combined therapeutic and diagnostic procedure in 31 of 69 women with impalpable screen-detected lesions. The majority of patients required further surgery because radiological abnormalities underestimated the extent of disease.
A method called "backprocessing", for subgross examination of sections, ranging between 50 microns and 1 mm in thickness using a dissecting microscope was developed. It requires either archival or current diagnostic breast tissue. In this study tissue is assumed to have been already embedded in paraffin wax for immediate diagnostic purposes. The advantages of backprocessing include the ability to select valuable or rare diagnostic tissue from archival histopathological material, and the preservation of histological structure should further examination at 5 microns thickness be required at a later date.
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Traditionally India ink has been used to mark surgical resection margins, more recently with acetone to aid drying. Alternative methods have been suggested in recent months, including solutions of alcian blue, and Tippex. These methods use one colour only and Tippex is radiodense. Artists' pigments have been used, but their radiodensity makes them unsuitable for the detailed mammograms of the sliced screened specimens. An alternative method was specifically designed for impalpable breast lesions. It is based on coloured gelatins that are painted on to the biopsy specimen before dissection. The markers are radiolucent, quick to set, and do not penetrate the connective tissue. They can be applied to both fresh and fixed tissues, and the cost is about 0.05 pounds a specimen. The system is also suitable for marking other large specimens.
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The fragile X syndrome is caused by the expansion of a polymorphic (CGG)n tract in the promoter region of the FMR1 gene. Apparently the incidence of fragile X syndrome is rare in the population of Greenland. In order to examine population-related factors involved in stability of the (CGG)n sequence, DNA samples obtained randomly from the Greenlandic population were analysed for size and AGG interspersion pattern of the FMR1 (CGG)n region and associated DXS548-FRAXAC1 haplotypes. In addition a large Greenland family with unstable transmission in the premutation range was analysed. The (CGG)n allele sizes in the Greenland population showed a narrow distribution similar to that reported for Asian populations. DNA sequencing of alleles with 36 CGG repeats revealed an AGG(CGG)6 insertion previously reported exclusively in Asian populations and a high frequency of alleles with a (CGG)10AGG(CGG)9AGG(CGG)9 or (CGG)9AGG(CGG)9AGG(CGG)6AGG(CGG)9 sequence pattern was found. Thus the data confirm the Asian origin of the Greenlandic (Eskimo) population and indicates that some (CGG)n alleles have remained stable for 15-30,000 years, since the population of the New World arrived from Asia via the Bering Strait.
The interleukin (IL)-12 levels and the superoxide dismutase (SOD) activity were determined in the seminal plasma of fertile and infertile men with or without leukocytospermia by ELISA. The IL-12 levels differed significantly among the fertile and infertile groups, with the infertile groups showing lower levels that were not modulated by leukocytospermia. The SOD activity did not differ significantly among the fertile and infertile groups and was not correlated with the IL-12 levels. The positive correlation with sperm concentration suggests that IL-12 may have a direct or indirect role in male fertility/infertility and that its levels are not modulated by the presence of leukocytes in the semen.
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