Biomedical subjects
Publications and source records attributed to M Hooper.
A chemical injury to the eye requires prompt and effective treatment to minimise permanent damage. This article describes the types of chemical injury and discusses the treatments available.
Recent reports of mammoplasia during selective serotonin re-uptake inhibitor (SSRI) therapy suggested that this side effect may be more common than previously reported. We examined 59 women receiving > or = 2 months treatment with an SSRI or venlafaxine for changes in breast size in relation to menopausal status, weight gain and duration of drug therapy. Serum prolactin, estradiol and beta-hCG were also measured before and during treatment in a subgroup of patients. Twenty-three out of 59 patients (39%) reported some degree of mammoplasia. Significantly more SSRI vs. venlafaxine patients reported mammoplasia (p < 0.01). Eighty-four percent with mammoplasia had weight gain vs. 30% without mammoplasia (p < 0.001). The rate of mammoplasia was unrelated to age, menopausal status or duration of treatment. Serum prolactin increased during treatment in the paroxetine subgroup (p < 0.03). In conclusion, antidepressant-induced mammoplasia may be more common than previously expected.
Patients who require a tracheostomy have particular needs associated with their care to ensure their safety and well-being. In this article, the author describes the reasons why a patient might have a tracheostomy and provides a detailed account of the anatomy, care and complications associated with it.
OBJECTIVE: The aim of this provocation study was to examine insulin, glucose, and cortisol levels in response to a glucose load in bulimia nervosa patients and to relate this to behavior, treatment status, and depressive symptomatology. METHOD: A 3-hr glucose tolerance test was performed in 15 female patients and in 4 controls. Tests were performed at different stages of treatment and following documented engagement in the patient's usual or previous repertoire of bulimic behaviors in the 24 hr prior to testing. Insulin, glucose, and cortisol levels were assayed at baseline and at 30-min intervals following the glucose load. Presence or absence of significant depressive symptomatology was ascertained. RESULTS: Three patterns of insulin response were identified: (1) an exaggerated response, (2) a normative response which resembled that of healthy controls, and (3) a blunted pattern. A reciprocal relationship between peak insulin and mean cortisol levels was seen with higher depression scores associated with blunted insulin response. Patients whose response was exaggerated binged and vomited relatively infrequently and were of stable weight. The insulin response of successfully treated patients, abstinent from binging and vomiting for 4 weeks, was similar to that of normal controls. A blunted response occurred in patients who binged and vomited more frequently, whose weight was unstable, and whose baseline eating was chaotic or nonexistent. DISCUSSION: The exaggerated insulin response was seen as a physiological adaptation to intermittent starvation reversible with treatment, while the blunted insulin response associated with higher cortisol levels was seen to result from more constant nutritional deprivation secondary to greater disturbance of behavior.
UNLABELLED: T cell activation initiated via the CD3/TCR complex requires signals provided by the interaction between costimulatory receptors on T cells and their corresponding ligands on accessory cells. Human dermal fibroblasts are reported to be deficient in this costimulatory activity and normally cannot serve as accessory cells for activation of resting T cells. We examined the contribution of human synovial fibroblasts to costimulatory activity for resting T cells. METHODS: Synovial fibroblast, dermal fibroblast, and umbilical cord endothelial cell cultures were established. These cell lines were co-cultured with purified peripheral T cells; and T cell activation was assayed using 3H-thymidine. RESULTS: Culturing resting T cells with synovial fibroblasts resulted in T cell proliferation with either mitogenic (periodate) or alloantigenic stimulation. This activation was dependent on the addition of interleukin 1 and/or gamma interferon. CONCLUSION: In contrast to dermal fibroblasts, synovial fibroblasts are able to provide costimulatory activity for activation of resting T cells.
The Pim-1 proto-oncogene encodes a highly conserved serine/threonine phosphokinase which is predominantly expressed in hematopoietic organs and gonads in mammals. Overexpression of Pim-1 predisposes to lymphomagenesis in mice. To develop a further understanding of Pim-1 in molecular terms, as well as in terms of its potential role in hematopoietic development, we have generated mice deficient in Pim-1 function. Pim-1-deficient mice are ostensibly normal, healthy and fertile. Detailed comparative analyses of the hematopoietic systems of the mutant mice and their wild-type littermates showed that they are indistinguishable for most of the parameters studied. Our analyses revealed one unexpected phenotype that correlated with the level of Pim-1 expression: Pim-1 deficiency correlated with a erythrocyte microcytosis, whereas overexpression of Pim-1 in E mu-Pim-1-transgenic mice resulted in erythrocyte macrocytosis. In order to confirm that the observed decrease in erythrocyte Mean Cell Volume (MCV) was attributable to the Pim-1 deficiency, we developed mice transgenic for a Pim-1 gene construct with its own promoter and showed that this transgene could restore the low erythrocyte Mean Cell Volume observed in the Pim-1-deficient mice to near wild-type levels. These results might be relevant to the observed involvement of the Pim-1 gene in mouse erythroleukemogenesis. The surprising lack of a readily observed phenotype in the lymphoid compartment of the Pim-1-deficient mice, suggests a heretofore unrecognized degree of in vivo functional redundancy of this highly conserved proto-oncogene.
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In vitro fertilization in the natural or spontaneous reproductive cycle was first described by Edwards and his colleagues in 1980 following the birth of their first natural cycle IVF baby 2 years earlier. Many groups attempted to follow their lead but it was almost ten years later that the next publication of success appeared (Foulot et al, 1989). The concept of IVF in the natural cycle is particularly attractive and so in 1987 our group also started evaluating the technique. Initial success in the patients with tubal lesions was not translated to patients with other infertility indications. Unfortunately the technique as initially developed was relatively inefficient with significant procedural losses at each stage. Over the succeeding four years a number of changes have been introduced and the efficiency considerably improved. Although these changes have improved take-home baby rates, overall pregnancy rates per embryo have not altered and are still lower than spontaneous in vivo pregnancy rates. It is likely that in the future, with current developments in culture techniques and greater understanding of gamete biology, this situation will change significantly.
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Specific genes can be inactivated or mutated in the mouse germ line. The phenotypic consequences of the mutation can provide pivotal information on the function of the gene in development and maintenance of the mammalian organism. The procedure entails homologous recombination in embryonic stem cells, which, on fusion to recipient blastocysts, give rise to chimaeric mice that can transmit the mutant gene to their offspring. Inbreeding can then yield mice carrying the mutation in both alleles allowing the phenotypic analysis of recessive mutations. In addition to mice lacking a particular gene function, cell lines carrying null alleles of normally expressed genes can be instrumental in assessing the function of the gene. These cell lines can either be obtained from homozygous animals or, should the mutation be lethal early in embryonic development, be generated by consecutive inactivation of both alleles by homologous recombination in cultured cells. Here we illustrate the feasibility of this latter approach by the efficient consecutive inactivation of both alleles of the pim-1 proto-oncogene in embryonic stem cells.
Ilio-tibial band syndrome is a common sports injury in runners that is easy to recognise and treat. Unfortunately, it is infrequently diagnosed so that much unnecessary morbidity from the condition exists.
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The dexamethasone suppression test (DST) has been widely used in psychiatry as a laboratory aid for the diagnosis of endogenous depression; failure to suppress serum cortisol levels is interpreted as confirming a clinical diagnosis of endogenous depression. We found that serum dexamethasone concentrations in this test vary widely and are determinants of the DST response: non-suppression of serum cortisol levels is associated with low serum dexamethasone concentrations, and suppression is associated with high concentrations.
Soluble antibody/3H-double-stranded PM2 DNA (dsDNA) immune complexes were briefly opsonized with complement and then allowed to bind to human erythrocytes (via complement receptors). The cells were washed and subsequently a volume of autologous blood in a variety of media was added, and the release of the bound immune complexes from the erythrocytes was studied as a function of temperature and time. After 1-2 h, the majority of the bound immune complexes were not released into the serum during blood clotting at either 37 degrees C or room temperature, but there was a considerably greater release of the immune complexes into the plasma of blood that was anticoagulated with EDTA. Similar results were obtained using various conditions of opsonization and also using complexes that contained lower molecular weight dsDNA. Thus, the kinetics of release of these antibody/dsDNA immune complexes differed substantially from the kinetics of release of antibody/bovine serum albumin complexes that was reported by others. Studies using the solution phase C1q immune complex binding assay confirmed that in approximately half of the SLE samples that were positive for immune complexes, there was a significantly higher level of detectable immune complexes in plasma vs. serum. Freshly drawn erythrocytes from some SLE patients exhibiting this plasma/serum discrepancy had IgG antigen on their surface that was released by incubation in EDTA plasma. Thus, the higher levels of immune complexes observed in EDTA plasma vs. serum using the C1q assay may often reflect the existence of immune complexes circulating in vivo bound to erythrocytes.
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