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Biomedical subjects

D Robinson

Publications and source records attributed to D Robinson.

At least 397 records · Page 22Linked to original sources

The infectious aetiology of tropical ulcer--a study of the role of anaerobic bacteria.

We have cultured anaerobic bacteria from patients with tropical ulcers. Fusobacteria were isolated most frequently. Anaerobes were always present, together with aerobes or facultative anaerobes, particularly in early phase ulcers, suggesting that the combination of organisms is important in the pathogenesis of the disease. Spirochaetes were identified in material examined by light and electron microscopy, but were not cultured.

Adolescent↗

Calcium, vitamin D and parathyroid hormone relationships in pregnant Caucasian and Asian women and their neonates.

Plasma calcium, serum 25 hydroxyvitamin D [25(OH)D], 1,25 dihydroxyvitamin D[1,25(OH)2D] and parathyroid hormone (PTH) have been measured in pregnant and newborn Caucasians and Asians. Calcium and 25(OH)D concentrations were lower in Caucasian than in Asian women at all four stages (three trimesters and during labour) of pregnancy. PTH concentrations were greater in Asian than in Caucasian women during the three trimesters, but not at labour, and increased in both groups through pregnancy, without a concomitant change in plasma calcium concentrations. There was a significant inverse correlation between calcium and PTH, as well as 25(OH)D and PTH, concentrations. These data demonstrate the presence of progressive 'hyperparathyroidism' during pregnancy in Caucasian and Asian women. The higher PTH concentrations in Asian women may reflect the necessity of maintaining adequate plasma calcium concentrations through PTH-induced osteolysis in the face of vitamin D deficiency. Relative hyperparathyroidism in Asians may contribute to net loss of calcium from the skeleton and osteopenia in Asian women. Calcium, 25(OH)D and 1,25(OH)2D concentrations were lower, and those of PTH higher, in Asian newborns compared with Caucasian newborns. Serum 1,25(OH)2D concentrations in the Asian newborn, though lower than respective maternal levels, were comparable with normal adult levels, indicating that 1,25(OH)2D biosynthesis is stimulated in the Asian newborn to compensate for the low serum 25(OH)D concentrations.

Alkaline Phosphatase↗

Alcohol problems: (i) Prevention at the local level.

The amount of alcohol consumed and its contribution to so many contemporary health and social problems, has led to a general consensus that 'something must be done'. Recent reports by 3 Royal Colleges highlighted important aspects of aetiology, treatment, and national prevention policy. In this first of a series of four papers, based on our DHSS-funded research and subsequent book Preventing Alcohol Problems: a guide to local action we trace the changing response to the alcohol problem, highlight the increasing emphasis on prevention, indicate the wide range of local prevention resources, and stress the vital role of health professionals in prevention at the local level.

Alcoholism↗

Serum gamma-GTP levels by type and quantity of alcohol consumed--the 'whisky hypothesis' refuted.

Serum gamma-GTP measurements in 11,755 Japanese men were used to test the hypothesis that drinking whisky had little or no effect on the serum level of this enzyme. We found that regular drinking was associated with significantly increased mean levels and raised percentages of high values of gamma-GTP, irrespective of the type of alcohol consumed. Moreover, heavier and more frequent drinking were associated with proportionately greater increases in gamma-GTP levels. Our data therefore refute the hypothesis that whisky drinking is not accompanied by adverse changes in the level of serum gamma-GTP.

Alcoholic Beverages↗

Morphological heterogeneity of Leu7, Leu11 and OKM1 positive lymphocyte subsets: an ultrastructural study with the immunogold method.

The morphological features of normal peripheral blood lymphocytes reactive with three monoclonal antibodies (MoAb) against natural killer (NK) cells, Leu7, OKM1 (CD11b) and Leu11 (CD16) and with two anti-T cell MoAb, CD4 and CD8, have been analysed at ultrastructural level by an indirect immunogold method. Cells having the features of large granular lymphocytes (LGL) but also lymphocytes displaying different morphological characteristics (non LGL; e.g. high nucleo-cytoplasmic ratio and few cytoplasmic organelles) were seen reactive with each of the MoAb investigated. Leu7 identified a higher proportion of LGL (60-80%) than OKM1 (10-95%) and Leu11 (20-48%), and with a stronger binding. A distinct granular structure, recognized as parallel tubular arrays, was more characteristic of the Leu7+, CD8+ LGL and was less frequently seen in the OKM1 and Leu11 positive LGL subpopulation in four out of the five donors investigated. It is of interest that the Leu11 and OKM1 positive subsets, which correspond functionally to cells with greater NK function, had relatively less LGL than the Leu7 positive subsets, raising the issue of the true morphology of NK cells in man. The existence of a minority of CD4 positive LGL was confirmed. Our findings demonstrate that there is a degree of morphological heterogeneity within the normal NK lymphoid population as defined by the membrane phenotype and that certain variability among normal individuals regarding the proportion and structural features of the NK subpopulations may be present.

Antibodies, Monoclonal↗

Aminomethyl coumarin acetic acid: a new fluorescent labelling agent for proteins.

A new fluorescent protein labelling agent, 7-amino-4-methyl coumarin-3-acetic acid (AMCA), emits in the blue region (440-460 nm) on activation with UV light (350 nm). The active reagent is the N-hydroxysuccinimide ester which reacts with lysine residues under mild conditions to form photostable amide links. The Stokes shift of 100 nm compared to 30 nm for Fluorescein isothiocyanate (FITC) allows easy filter discrimination of exciting and emitting radiation. The agent has been demonstrated in use for fluorohistochemical examination of human kidney glomeruli, using the sandwich technique and compared with the same procedure using FITC-labelled antibodies. The good quantum yield coupled with convenient emission lines in the mercury spectrum allows photographic exposure time of fluorescent labelled sections to be reduced to a quarter of that required for a corresponding FITC conjugate. AMCA-immunoglobulin conjugates were not susceptible to photobleaching and have a storage life at -20 degrees C of more than two years.

Antibodies, Monoclonal↗

Parathyroid hormone and neonatal calcium homeostasis: evidence for secondary hyperparathyroidism in the Asian neonate.

Calcium, 25-hydroxyvitamin D (25 OHD), and parathyroid hormone (PTH) concentrations were measured in 11 Asian and ten Caucasian pregnant women at parturition and in their respective newborns following a full term normal delivery. Maternal calcium and 25 OHD concentrations were significantly lower while PTH concentrations were significantly greater in Asians than those in Caucasians. There was a significant inverse relationship between calcium and PTH and the relationship between 25 OHD and PTH concentrations. Neonatal calcium and 25 OHD concentrations were also significantly lower and PTH concentrations significantly higher in Asians than those in Caucasians. There was a highly significant inverse correlation between neonatal calcium and PTH concentrations. Three of the 11 Asian babies had supranormal concentrations of PTH in their cord blood. We conclude that PTH participates in neonatal calcium homeostasis and Asian newborns have frequent secondary hyperparathyroidism.

Adult↗

Low plasma triglyceride levels in lake dwelling East African tribesmen--a fishy story?

Samples of East African tribesmen from two separate locations were compared with respect to a number of anthropometric, cardiovascular and biochemical variables. The major finding was a large, significant difference in mean triglyceride levels between the groups (0.97 vs. 0.67 mmol/l; p less than 0.001), the mean plasma triglycerides being 31% lower in those for whom fish formed a substantial part of their daily food intake.

Adult↗

Immunologic differentiation of the Sézary syndrome due to cutaneous T-cell lymphoma and chronic actinic dermatitis.

Peripheral blood mononuclear cells from two well-defined groups of patients with the Sézary syndrome have been studied employing indirect immunofluorescent and indirect immunogold techniques in light and electron microscopy, using monoclonal antibodies against T-cell subpopulations. Four patients had chronic actinic dermatitis (CAD) of the actinic reticuloid variant, with erythroderma. Eight patients had cutaneous T-cell lymphoma. All patients showed the clinical features of the Sézary syndrome, including erythroderma, palmoplantar hyperkeratosis, and peripheral lymphadenopathy, and in all patients significant numbers (0.5-30.5 X 10(9) cells/liter) of circulating mononuclear cells were observed with Sézary cell morphology on light-microscopic examination of blood films. Major differences were observed in the circulating T-cell subpopulations in the two groups. In the erythrodermic CAD patients, there was a moderately elevated T-cell count (1.6 +/- 0.6 X 10(9) cells/liter; normal, 1.0 +/- 0.3 X 10(9) cells/liter) of which the majority of the cells was suppressor T cells (OKT8+) giving a very low helper:suppressor T-cell ratio of 0.1:1-0.36:1 (normal, 1.7:1-3.5:1). In cutaneous T-cell lymphoma, there was also an elevation of the T-cell count (9.5 +/- 12.9 X 10(9) cells/liter), but in these patients the predominant cell was the helper T cell (OKT4+) with a high helper:suppressor T-cell ratio of 3.7:1-98:1.

Antibodies, Monoclonal↗

HDL-cholesterol subfractions in healthy males: relation to serum triglyceride levels and age.

The relationship between plasma HDL-cholesterol subfractions (HDL2 and HDL3), measured using a differential precipitation method, and serum triglycerides, was studied in 402 healthy Caucasian males attending a health screening centre in London. Mean values for HDL2 and HDL3 were 0.42 +/- 0.24 mmol/L and 0.81 +/- 0.15 mmol/L respectively. HDL2 was found to show a stronger negative correlation with serum triglyceride and a stronger positive correlation with total HDL than HDL3. HDL2 also showed a stronger correlation with age than either total HDL or HDL3. Mean levels of HDL2 were 20% higher in subjects over 55 years of age compared with those who were less than 55 years of age. Reference values of HDL2 and HDL3 are presented for different age ranges.

Adult↗

Alternative treatments for withdrawing the long-term benzodiazepine user: a pilot study.

Anxiolytic therapy with benzodiazepines and their potential for dependence are reviewed. Relaxation training and biofeedback have been used for chemically dependent anxious patients. These techniques have been recommended for benzodiazepine-dependent patients, but not investigated. Previous withdrawal studies offer only limited follow-up data. Stress management treatment was based on a successful case study. Recruitment difficulties were encountered. However, seven patients were randomly assigned to stress management or brief psycho-therapy. All showed improvement, but three of four patients available for 1 year follow-up had returned to pretreatment dependence. These withdrawal difficulties suggest the need for more effective treatments and more adequate follow-up studies.

Adult↗

Survival in bilateral breast cancer.

The presence of bilateral invasive breast cancer places the patient in a state of double jeopardy. At Memorial Sloan-Kettering Cancer Center, the overall 10-year recurrence rate for unilateral Stage I breast cancer was 16%, whereas the recurrence rate for simultaneous, bilateral Stage I breast carcinoma was 29%: almost twice as high. The average 10-year survival of all patients with negative axillary nodes was 57%. In this retrospective analysis of 403 patients with bilateral primary operable breast cancer treated at Memorial Sloan-Kettering Cancer Center, significant differences were noted in the disease-free survival between patients with bilateral noninvasive cancer, bilateral invasive cancer, and the combination of invasive and in situ cancers. Bilateral intraductal cancer and lobular carcinoma in situ offered an excellent prognosis. The combination of preinvasive cancer on one side and infiltrating carcinoma on the other had the next best survival. The in situ lesion, when treated by mastectomy, did not alter the patients' life expectancy from that of the general population with unilateral breast cancer, thus indicating that surgeons should strive to detect breast cancer in its preinvasive form. The 5- and 10-year relapse-free survival of patients with bilateral invasive disease, regardless of axillary nodal status and tumor size, was 60% and 51%, respectively, for patients with a bilateral presentation and 54% and 38%, respectively, for carcinomas presenting metachronously. More important in determining prognosis, however, was the number of axillary nodes involved and the level of involvement. Invasion of bilateral axillary nodes at all levels predicted a poor prognosis. Because of this shortened survival, systemic adjuvant therapy should be considered for patients with bilateral invasive disease. The most common preinvasive breast cancer was lobular carcinoma in situ and the most frequently invasive tumor was infiltrating duct cancer. Since a contralateral breast cancer at the time of definitive treatment of the first side does not always present as a mass or with positive mammography, a random biopsy of the second breast is recommended. This should be done in the upper, outer quadrant and should include the subareolar area. With prompt adequate treatment, it is expected that survival from bilateral breast cancer should improve.

Breast Neoplasms↗