Capillary blotting of agarose gels.
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Biomedical subjects
Publications and source records attributed to D Murphy.
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It is well established that oestrogens can stimulate prolactin (PRL) secretion as well as the expression of the vasoactive intestinal peptide (VIP) gene whose product is also a potent PRL secretagogue. Previous evidence has supported both an autocrine and a paracrine role for pituitary VIP in PRL release in vitro; however, the cellular origin of VIP in pituitary tissue still remains poorly defined. In these studies, we have demonstrated by in situ hybridisation that VIP RNA is detected in the anterior pituitaries of chronically hyperoestrogenised rats, but not in those of untreated animals. Using a double-probe labelling procedure, VIP RNA has been shown to be present in a subpopulation of PRL-producing cells, while colocalisation of VIP and GH RNA was not observed. VIP gene expression in the rat anterior pituitary gland was characterised by the presence of two alternatively polyadenylated transcripts, 1.7 kb and 1.0 kb in size. We have generated a probe specific for the 1.7 kb transcript and double-labelling studies also showed definitive colocalisation with PRL mRNA. Our results demonstrating the presence of VIP RNA in PRL-producing cells thus suggest that VIP may play an autocrine role in PRL hypersecretion under conditions of oestrogen-induced hyperplasia.
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The aims of this study were to establish a profile for the expression of p53 in primary renal cell carcinoma using the polyclonal antibody NCL-CB1 and the monoclonal antibody D07, and to compare the results of staining with both antibodies. Ninety-six cases were studied using formalin-fixed paraffin-embedded tissue. Positive nuclear staining ranged from 5% (D07) to 12% (NCL-CM1). Positive cytoplasmic staining ranged from 7% (D07) to 25% (NCL-CM1) of cases. Interobserver agreement was excellent. The findings suggest that such a low level of immunohistochemical positivity reduces any potential prognostic value for p53 in this tumour type.
Parkinson's disease (PD) is a chronic and progressive degenerative disorder of the central nervous system characterized by tremor, rigidity, slowness of movement (bradykinesia) and postural abnormalities. The cause is unknown, but the pathology shows that dopamine is profoundly reduced in the basal ganglia of patients with PD. When dopamine is replenished by the administration of levodopa, most of the symptoms of parkinsonism are reduced significantly. Levodopa is considered to be the most reliable and effective symptomatic drug treatment for keeping patients autonomous and functionally independent for as long as possible.
To gain insights into the molecular mechanisms that restrict the expression of the oxytocin gene to anatomically defined groups of neurons in the hypothalamus, we generated transgenic mice bearing bovine oxytocin genomic fragments. Appropriate neuron-specific and physiological regulation was observed in mice bearing transgene bOT3.5, which consists of the oxytocin structural gene flanked by 0.6 kilobase pair (kbp) of upstream and 1.9 kbp of downstream sequences. bOT3.5 is expressed in oxytocin magnocellular neurons in the mouse supraoptic nucleus and paraventricular nucleus, but transgene RNAs are excluded from vasopressin neurons. Replacement of the drinking diet of the transgenic mice with 2% (w/v) NaCl for 7 days significantly increased the abundance of bovine oxytocin transcripts in the supraoptic nucleus, but not in the paraventricular nucleus, in parallel with the endogenous mouse oxytocin RNA. Surprisingly, mimicry of the endogenous oxytocin gene expression pattern was lost with larger transgenes. Addition of 0.7 kbp of contiguous downstream sequences (transgene bOT) or linkage to the bovine vasopressin gene (transgene VP-B/bOT3.5) repressed hypothalamic expression. No mice were derived bearing transgene bOT6.4, which consists of the oxytocin structural gene flanked by 3 kbp of upstream and 2.6 kbp of downstream sequences, suggesting that the presence of this DNA is detrimental to normal embryonic development. These data suggest that while bOT3.5 contains sufficient cis-acting sequences to mediate expression to particular subsets of hypothalamic neurons, the overall regulation of the oxytocin gene is governed by multiple interacting enhancers and repressors.
Damnacanthal, an anthraquinone isolated from a plant extract, was found to be a potent, selective inhibitor of p56lck tyrosine kinase activity. The structure, potency, and selectivity of damnacanthal were confirmed by independent synthesis and testing. Damnacanthal exhibited an IC50 of 17 nM for inhibition of p56lck autophosphorylation and an IC50 of 620 nM for phosphorylation of an exogenous peptide by p56lck. Damnacanthal had > 100-fold selectivity for p56lck over the serine/threonine kinases, protein kinase A and protein kinase C, and > 40-fold selectivity for p56lck over four receptor tyrosine kinases. It also demonstrated modest (7-20-fold), but highly statistically significant, selectivity for p56lck over the homologous enzymes p60src and p59fyn. Mechanistic studies demonstrated that damnacanthal was competitive with the peptide binding site, but mixed noncompetitive with the ATP site. Although damnacanthal contains a potentially reactive aldehyde moiety, equilibrium dialysis experiments demonstrated that significant amine formation between damnacanthal and amines occurred only at high concentrations of reactants. However, damnacanthal appeared to bind nonspecifically to membrane lipids and was not active in whole cell tyrosine kinase assays. Damnacanthal is the most potent, selective inhibitor of p56lck tyrosine kinase activity described to date and may represent the starting point for the identification of novel, selective inhibitors of p56lck which are active in whole cell as well as in cell-free systems.
The peptide arginine vasopressin (AVP) is present within tissues of the immune system and has been implicated in T cell differentiation. We have investigated the expression and production of AVP in the thymus of rats which carry a rat AVP transgene. A 100% increase in thymic AVP immunoreactivity (ir) was detected in transgenic (TG) animals compared to age-matched wild-type (WT) controls. When tissues from TG and WT thymuses were subjected to reversed-phase high-performance liquid chromatography, ir-AVP eluted as a single peak which co-eluted with the standard. Immunocytochemical staining identified the presence of AVP in large epithelial cells within the thymic cortex in both WT and TG animals. The AVP precursor product neurophysin was also detected in epithelial cells in WT and TG thymuses. In situ hybridisation histochemistry using a probe specific for transgenic AVP mRNA revealed that the AVP transgene was expressed in TG thymic cells with a similar morphology and distribution to those which expressed endogenous AVP peptide in WT animals. These results demonstrate that the cellular location and immunoreactive form of AVP expressed in TG animals are similar to that found in WT controls. Thus the TG rat appears to be a model of true physiological, rather than ectopic, over-expression of AVP in the thymus. The hyper-expression of AVP in the thymic epithelial cells of TG animals provides a model in which can be studied the influence of AVP on T cell development and differentiation within the thymus.
The ability of a single injection of steroid and lidocaine to bring about cure of primary trigger finger was determined and compared with a control placebo injection of only lidocaine. Twenty-four patients were randomized to the therapeutic or control group and were followed prospectively. One physician administered the injection, another the clinical examination after injection, and a third evaluated the results blindly. Patients were not told to which group they were assigned. Nine of the 14 patients in the steroid group versus two of the ten patients in the placebo group were cured of trigger finger at final follow-up examination. After injection, seven patients had immediate but temporary relief of triggering because of flexor sheath distention. One injection cured 64% [corrected] of patients with primary trigger finger with no side effect and is the recommended nonsurgical treatment.
Self-hypnosis was taught to 34 self-identified allergy patients who attended two training classes. They practiced on their own and were questioned two months later. Seventy-six percent of the subjects reported they felt an improvement in their symptoms; 86% of those who were medicated decreased their medicines. Practice was clearly related to reported improvement. "Feeling hypnotized" was not related to improvement.
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Reactive drug metabolites have been implicated in the pathogenesis of adverse reactions to the aromatic anticonvulsants. A patient presented with a hypersensitivity reaction to the aromatic anticonvulsants which evolved into Stevens-Johnson syndrome and was complicated by the presence of adult respiratory distress syndrome. When the patient's cells were tested for sensitivity in vitro to reactive metabolites of the aromatic anticonvulsants, they were markedly more sensitive to metabolites of the aromatic anticonvulsants than were the cells of controls (p < 0.05). The adult respiratory distress syndrome has not previously been described as a complication of hypersensitivity reactions to the aromatic anticonvulsants. In vitro testing also demonstrated cross-sensitivity to the anticonvulsants, allowing selection of a therapeutic regimen which would not be associated with a risk of exacerbating the hypersensitivity reaction.
BACKGROUND AND PURPOSE: CGS 19755 is a competitive N-methyl-D-aspartate (NMDA) receptor antagonist that limits neuronal damage in animal stroke models. The objectives of this multicenter (7 centers), randomized, double-blind, placebo-controlled, ascending-dose phase IIa study were to evaluate the safety and tolerability of CGS 19755 and obtain pharmacokinetic and preliminary data on its efficacious dose range in patients treated within 12 hours of hemispheric ischemic stroke. METHODS: At each dose level, 6 patients were randomized to one or two intravenous bolus doses of CGS 19755, and 2 patients were randomized to placebo. An unblinded safety and monitoring committee-evaluated results at each dose before ascending to the next level. All patients at the first level (1 mg/kg) received two doses separated by 12 hours. The first 2 patients at 2 mg/kg received two doses, but adverse experiences occurred in both; subsequent patient groups received single doses of 2.0, 1.75, or 1.5 mg/kg. RESULTS: Adverse experiences (agitation, hallucinations, confusion, paranoia, and delirium) occurred in all 6 patients treated with 2 mg/kg, and in 3 of 5 at 1.75 mg/kg. Similar but milder adverse experiences were noted in 4 of 7 patients at 1.5 mg/kg and 1 of 6 patients at 1.0 mg/kg. Adverse experiences began between 20 minutes and 22 hours (mean, 8 hours) after treatment and lasted 2 to 60 hours (mean, 24 hours). Mortality was 1 of 8 in patients receiving placebo and 3 of 24 in treated patients. In treated survivors, median and mean percent improvement in National Institutes of Health Stroke Scale scores from baseline to terminal visit (mean, 86 days) was comparable at all doses, and 95% of treated patients had Barthel Index scores of > or = 70 at the terminal visit. CONCLUSIONS: We conclude that a single intravenous dose of 1.5 mg/kg CGS 19755 is safe and tolerable in patients with acute ischemic stroke. An efficacy trial is indicated.
A severe persistent neutropenia developed in a rabbit that was injected intradermally with 120, 60, 60, and 120 micrograms of recombinant canine granulocyte colony-stimulating factor (cG-CSF) on days 1, 22, 31, and 44, respectively. The neutropenia was present from day 44 to day 205. The nadir of the neutropenia (60 cells/microliters) occurred in conjunction with peak antibody titer (640,000) to cG-CSF on day 58. The immune antiserum from this rabbit reacted positively for cG-CSF on Western blot analysis. The immune antiserum also neutralized the activity of cG-CSF. On day 160, examination of the bone marrow showed marked granulocytic hypoplasia and mild erythroid hyperplasia. On day 205, the rabbit was still neutropenic (430 cells/microliters), even though the last injection of cG-CSF was given 161 previously. Necropsy on day 205 showed that there was still mild granulocytic hypoplasia with mild erythroid hyperplasia. Because of the lack of any inflammatory foci found at necropsy and the granulocytic hypoplasia, it was thought that the neutropenia was most likely due to decreased production and was not a consumptive process. It is hypothesized that the antibody that was produced to cG-CSF neutralized the effect of endogenous rabbit granulocyte colony-stimulating factor and prevented the normal proliferation and maturation of the rabbit neutrophils.
Notoedric mange (Notoedres cati) was found in a neonate Florida panther (Felis concolor coryi) and presumably its mother on 22 June 1992 and 8 February 1993, respectively, in Collier County, Florida (USA). Both infestations were treated successfully with 0.2 mg/kg ivermectin. This is the first known case of notoedric mange in the endangered Florida panther.
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We have compared the expression patterns in transgenic mice of bovine oxytocin constructs consisting of the 0.9 kilobase pair (kbp) structural gene flanked by varying lengths of upstream and downstream sequences. Over 200 offspring were derived from fertilized one-cell mouse eggs injected with construct bOT6.5, which consists of 3 kbp of upstream sequences and 2.6 kbp of downstream sequences. However, no transgenic founders were identified. In parallel experiments with other constructs, 30% of pups carried integrated copies of the injected transgene DNA. It therefore appears that bOT6.5 is toxic to mouse embryos. As previously reported (Ang et al., 1991), bOT, consisting of 2.6 kbp of downstream sequences and 0.6 kbp of upstream sequences, was expressed in lung and in testicular Sertoli cells, but no expression was detected in the hypothalamus. bOT3.5, which consists of 0.6 kbp of upstream sequences and 1.9 kbp of downstream sequences, retains testis and lung expression, but, surprisingly, is also expressed in the hypothalamus. These data suggest that the 0.7 kbp of downstream sequences that are present in bOT, but which are absent from bOT3.5, contain elements that mediate the repression of hypothalamic expression. The activity of this repressor must be itself overcome in the normal genomic context of the bovine OT gene. Within the hypothalamus, in situ hybridisation analysis has revealed expression of bOT3.5 in the supraoptic nucleus (SON) and paraventricular nucleus (PVN), but not in the suprachiasmatic nucleus (SCN). In parallel with the response of the endogenous murine OT RNA, 7 days of salt-loading resulted in a significant increase in the level of transgene RNA in the SON. In the PVN, neither the endogenous OT RNA nor the transgene RNA responded significantly to salt-loading. Transgene RNA levels in the hypothalamus have also been shown to be elevated during late pregnancy and lactation.
A transgenic mouse model has been developed to test the involvement of ectopic neuropeptide production as a secondary factor in cancer. Mice bearing a mouse mammary tumor virus-vasopressin (MMTV-VP) fusion transgene synthesized authentic vasopressin in mammary ducts and alveoli, but this had no effect on mammary gland development and growth. Mice bearing the MMTV-VP transgene were then mated with mice bearing the MMTV-Wnt-1 transgene to produce bitransgenic animals. Two types of mammary tumor develop in MMTV-Wnt-1 mice; type A mammary adenocarcinomas are uniform with fine acinar structure composed of small epithelial cells arranged to form round cavities and elongated tubules, while adenocarcinoma type B tumors have acinar areas, cystic spaces filled with blood or fluid, intracystic papillary projections, and cords as well as sheets of cells. Compared to the MMTV-Wnt-1 mice, the bitransgenic animals developed proportionally less type B tumors. Further, type B mammary adenocarcinomas from bitransgenic mice exhibited increased proliferation and growth, as judged by mitotic index and argyrophilic nucleolar organizer region counts, compared to type B tumors from MMTV-Wnt-1 mice. These data provide evidence that ectopic neuropeptide production can modulate the development of tumors in vivo.