A ROSE is A. Rose is a rose? Exploring the implicit and explicit memorial structure of word/name homographs.
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Biomedical subjects
Publications and source records attributed to B Brooks.
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Cholate-extracted lipopolysaccharide (LPS) antigens from thermophilic campylobacters were captured on polymyxin-coated polyester cloth. The captured antigens were detected by sequential reactions with rabbit anti-Campylobacter antibody, anti-rabbit IgG peroxidase conjugate and chromogenic peroxidase substrate. A polyclonal rabbit antibody elicited against a single Campylobacter-jejuni strain detected the reference strains of the twenty most frequently isolated thermophilic campylobacters in the Lior serotyping scheme. Moreover, LPS antigens of six C. Jejuni Penner serotypes fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and examined by immunoblotting were recognized by four antisera prepared against homologous and heterologous Penner serotypes. The results suggest the potential application of polymyxin-cloth enzyme immunoassay for rapid detection of thermophilic campylobacters where monoclonal antibodies can be raised to possible common LPS epitopes.
Using a flow cytometric assay, conjugate formation between human peripheral blood mononuclear cells (PBMC) and three different human tumour cell lines has been analysed. Changes in the intracellular calcium levels of PBMC were monitored using the calcium sensitive dye Fluo-3. Target cell populations were distinguished by forward scatter or following loading with the fluorescent dye, SNARF-1. Intracellular calcium was expressed as a ratio of fluorescence of conjugated to unconjugated PBMC and followed for ten minutes after initiation of conjugation. The results demonstrate an apparent increase in intracellular calcium in PBMC conjugated to the NK-sensitive cell line K562, and that the kinetics and magnitude of this response varied considerably between individuals. Tumour cells which were resistant to lysis (as determined in a 4 h chromium release assay) were also capable of eliciting a calcium response from PBMC. Although the induction of a rise in intracellular calcium was therefore not correlated with cytotoxicity, it was greater in IL-2-activated PBMC upon exposure to the same target cell lines as PBMC.
To evaluate the integration of children with spina bifida into adult society and identify important urological factors 20 female and 18 male spina bifida patients older than 18 years were evaluated with respect to urological management and complications. A detailed questionnaire concerning educational achievements, living arrangements, employment and interpersonal relationships was completed and compared to similar data obtained from the 1990 United States census. Educational achievement and living arrangements for most patients were comparable to age matched peers in the general population and were independent of gender or method of urinary management. The only statistically significant factor related to a positive outcome was female gender in the areas of employment (p < 0.014) and sexual relationships (p < 0.005). Female spina bifida patients adapted better to adult society than their male counterparts. Intestinal urinary conduits were detrimental to long-term renal function.
Although school nurses may be unfamiliar with adolescent body piercing, they are in a key position to assist students who are considering these procedures. Information about various types of body piercing, student experiences, and teaching strategies to talk with adolescents about this procedure are presented. Nurses can utilize the data to help students make informed decisions about body piercing.
Tyrosine 14 of delta 5-3-ketosteroid isomerase plays an important role in the function of the enzyme, since its replacement by phenylalanine results in a decrease in kcat by a factor of 10(-4.7). This result and the fact that this residue resides in the enzyme's substrate binding site and is in close proximity to C-2 of the bound steroid suggests that it functions as an electrophile in the catalytic mechanism by protonation of or hydrogen bonding to the C-3 carbonyl oxygen of the substrate. In order to obtain more information about the role of tyrosine 14, we have prepared a modified form of the enzyme in which tyrosine 14 has been substantially replaced in vivo by exogenously supplied 3-fluorotyrosine, a tyrosine derivative in which the pKa' of the phenol hydroxyl should be decreased by about 1.5 log units. Site specificity of this modification has been ensured by mutation of the codons for the nonessential tyrosines 55 and 88 to phenylalanine. We find that replacement of tyrosine 14 by 3-fluorotyrosine in the Y55,88F modified form of the isomerase results in a 4-fold decrease in kcat. We interpret this result in terms of a mechanism in which the transition state for enolization is dienolate-like, characterized by relatively little proton transfer from tyrosine 14 in the transition state, and the intermediate in the overall reaction is dienol-like. An alternative mechanism in which the intermediate is stabilized by a short, strong hydrogen bond can also be consistent with the data.
It is well documented that mycosis fungoides (MF), a cutaneous T-cell lymphoma, has a variable clinical course. Unbiased stereological estimates of three-dimensional volume-weighted mean nuclear size (nucl vV) of mycosis cells were obtained in a retrospective study of 18 patients with a total of 34 biopsies of cutaneous plaque and tumor-stage MF. The value of nucl vV in the first sampled biopsy, as well as the average and highest values, were determined in biopsies from each patient. The patients were divided into two groups, either above or below the group median. There was a strong positive correlation between shorter survival and an average value of nucl vV > 104 microns 3 or a highest value of nucl vV > 126 microns 3 (2p = 0.002 and 0.003, respectively). A nucl vV > 91.6 microns 3 in the first biopsy was also suggestive of a shorter survival (2p = 0.07). There was no clear pattern of nucl vV evolution in the patients with multiple biopsies, but the impact of various therapeutic regimens cannot be assessed. Certain estimates of nucl vV appear to be good prognostic indicators in plaque and tumor-stage MF, but further study of a larger series of patients is needed to corroborate these results and assess the impact of differing therapeutic regimes.
This study compares the declared splits for abdominal surgery within the Australian National Diagnosis Related Groups (AN-DRG) with age-based strata. Data were derived from two clinical trials involving 2114 adults. The patients tended to be elderly (25% > 71 years) and had significant co-morbidity, that is, 57% with an American Society of Anesthesia (ASA) classification > 1. Adverse events after surgery included pulmonary complications (16%), urinary tract infections (10%), wound infection (6%), and death (4.5%). Only 27% of the patients could be classified into a 'non-complicated' AN-DRG partition; these patients had a median age of 25 years and 88% had either appendicectomy or cholecystectomy. In contrast, analysis of six age-based strata revealed a stepwise increase in the incidence of adverse events after surgery (Friedman ANOVA, P < 0.001). It might therefore be wise to consider the inclusion of age-strata in the abdominal surgery component of the AN-DRG. Failure to do so may result in financial penalties for hospitals that care for patients at high risk of an adverse outcome after abdominal surgery.
Patients with noninsulin-dependent diabetes mellitus (NIDDM) are often obese and frequently complain of tiredness. These features are also characteristically seen in patients with obstructive sleep apnea (OSA). Therefore, it was the aim of this study to assess the prevalence of OSA among a group of obese NIDDM patients who have some clinical features of OSA. The effect of reversal of OSA by nasal continuous positive airway pressure (CPAP) treatment on insulin responsiveness was also investigated. From a population of 179 NIDDM patients with a body mass index (BMI) greater than 35 kg/m2, we performed ambulatory sleep monitoring on 31 (15 males and 16 females) who admitted to either heavy snoring or excessive sleepiness. Results were reviewed by a sleep physician blinded to the clinical status of the patients, and 22 (70%) were found to have moderate or severe OSA, with mean oxygen desaturation indexes of 10.3 +/- 5.3 and 30.7 +/- 13.2 episodes/h, respectively. A subgroup of 10 patients (seven males and three females) with a mean BMI of 42.7 +/- 4.3 kg/m2 was treated with nightly CPAP for 4 months. These subjects all had significant OSA, with frequent obstructive apneas (mean, 47 +/- 31.6 episodes/h) and oxygen desaturation (mean minimum O2 saturation, 74 +/- 9.5%), as determined by polysomnography. One patient was excluded from analysis because of infrequent use of CPAP. Insulin responsiveness in terms of glucose disposal measured by hyperinsulinemic euglycemic clamps improved from 11.4 +/- 6.2 to 15.1 +/- 4.6 mumol/kg.min (P < 0.05) during CPAP treatment. These results indicate that OSA occurs commonly in obese NIDDM patients with excessive sleepiness or heavy snoring. Treatment of their OSA may improve insulin responsiveness.
Medullipin I (Med I) is a vasodepressor prohormone which is continuously elaborated into the renal venous effluent (RVE) of isolated rat kidneys perfused under high pressure. We have improved the yield of Med I by substituting saline for the albumin perfusate previously reported; and considerably improved refinement by directly fractionating the crude lipid extract of the RVE with high pressure liquid chromatography. The results show that Med I, as defined by previous physiologic and pharmacologic criteria, is not a single molecule. The 3 Class I medullipins described here are distinguished by subtle or overt differences in polarity and biologic activity.
OBJECTIVE: To determine whether secretion of medullipin I by the kidney is dependent on the cytochrome P-450 enzyme system in Sprague-Dawley and spontaneously hypertensive rats (SHR). METHODS: Isolated kidneys from Sprague-Dawley rats were perfused with 5% human albumin gassed with 95% O2 and 5% CO2 at 185 mmHg. The resultant renal venous effluent was tested in the SHR for medullipin I-type vasodepressor activity. The kidneys were then treated with ketoconazole, and inhibitor of the cytochrome P-450 enzyme system. After rinsing with 50 ml saline, the last 10 ml of which was saved for a control test (see below), the kidneys were reperfused with 50 ml human albumin and the resultant renal venous effluent was tested for vasodepressor activity. One milliliter of the saline rinse was administered to the SHR and the preketoconazole renal venous effluent was administered after 15 min. The medullipin I-type vasodepression occurred. Thus, inhibition of vasodepression after ketoconazole treatment was not due to residual ketoconazole in the post-treatment renal venous effluent. RESULTS: Treatment of isolated kidneys with ketoconazole prevented secretion of medullipin I which had been induced by 5% human albumin. CONCLUSION: The cytochrome P-450 enzyme system is involved in two major metabolic steps of the medullipin system: synthesis of medullipin I by the kidney and conversion of medullipin I to medullipin II by the liver as shown previously.
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The effect of 40- to 60-mesh hydroxyapatite (HA) granules (Calcitek, Inc., Carlsbad, CA) on the process of primary mineralization during bone healing was examined following insertion of the HA granules into rat tibial bone after marrow ablation. Response to HA was assessed by monitoring morphometric and biochemical changes in matrix vesicles, which are extracellular organelles associated with initial calcification. Following insertion of HA, matrix vesicle-enriched membranes (MVEMs) were isolated from the tissue adjacent to the implant and from the endosteum of the contralateral limb at 3, 6, 14, and 21 days and from a nonimplanted control group (t = 0). MVEM alkaline phosphatase- and phospholipase A2-specific activities were increased on days 6 (peak) and 14; phosphatidylserine content was also elevated on days 6 and 14 (peak). Comparable changes were seen in the contralateral limb but at lesser magnitudes. Morphological changes were observed as well. The number of matrix vesicles/micron2 matrix increased on days 6 (peak) and 14. The mean diameter of the matrix vesicles was elevated on days 6 (peak), 14, and 21. Mean distance from the calcifying front increased on day 6 but was decreased on days 14 and 21. These results indicated that HA behaves like bone-bonding implants in that there is a stimulation of matrix vesicle enzymes, increased phosphatidylserine content, and increase numbers of matrix vesicles. However, the increases occur only after 6 days postimplantation, indicating a delay in response when compared to normal healing. This delay is confirmed by the morphometric measurements. HA causes a reduction in the response associated with marrow ablation. In addition, the effects of HA are comparable locally and systemically but with different intensity. These observations suggest that osteogenic cells are able to compensate for the inhibitory effects of HA and primary calcification involves normal matrix vesicle production and maturation, if somewhat delayed and reduced in magnitude. The ability to support primary mineral formation may contribute to the successful bonding of HA with surrounding osseous tissue.
The classification of renal cortical tumours is problematic, with no clear division of benign from malignant tumours. Unbiased stereological estimates of volume-weighted nuclear volume (nuclear vv) were obtained by point sampling of nuclear intercepts in a retrospective study of 36 variably sized tubulo-papillary basophilic cell renal cortical tumours. There was no clear pattern of evolution of nuclear vv with increasing macroscopic tumour diameter. Estimates of nuclear vv could not distinguish between 21 tumours classified as renal adenomas with macroscopic diameters < 3 cm (average nuclear vv = 241 microns 3) and 15 tumours classified as renal cell carcinomas with diameters > 3 cm, or aggressive histological pattern (average nuclear vv = 229 microns 3) (2p = 0.68). In this subtype of renal cortical tumours, estimates of nuclear vv do not support the historical convention of using a 3 cm tumour diameter as the dividing line between adenomas and carcinomas, but support the theory of a single group of tumours. As most of the truly incidental renal cortical tumours are less than 1 cm in diameter, this limit could be considered. Such small benign cortical nodules have never been reported to metastasize, and would thus be excluded from being diagnosed and registered as malignant. Although this dividing line is again arbitrary, and cannot be justified by the stereological measurements, it is a practical solution to a clinical problem. There were too few examples of disease progression to assess the prognostic significance of nuclear vv in these tumours.
Chondrocytes in the endochondral differentiation pathway produce transforming growth factor-beta (TGF-beta) and response to this growth factor both in vitro and in vivo. To clarify the role that cell maturation state plays in the response, we used a well characterized chondrocyte cell culture model which compares cartilage cells at two different stages of maturation. Confluent fourth passage cultures of rat costochondral resting zone and growth zone cartilage cells were incubated with recombinant human (rh) TGF-beta-1 for 24, 48, or 72 h, and the effect on cell number and [3H]thymidine incorporation was observed. To assess whether TGF-beta regulates chondrocyte differentiation to a calcifying cartilage phenotype, cells were incubated for 24 h with TGF-beta, and the specific activities of alkaline phosphatase and phospholipase A2, two enzymes associated with calcification, were assayed in isolated plasma membranes and matrix vesicles. Alkaline phosphatase-specific activity was also measured in the cell layer. Modulation of TGF-beta action by vitamin D metabolites, also known to regulate endochondral differentiation, was examined. The ability of the chondrocytes to produce latent TGF-beta was assayed. The results show that: 1) quiescent chondrocytes at two stages of endochondral maturation respond to rhTGF-beta-1 by increasing [3H]thymidine incorporation; 2) growth zone cells exhibit no increase in cell number over a 72-h incubation with TGF-beta, whereas resting zone cells exhibit a dose-dependent increase in cell number at 72 h; 3) nonquiescent cells exhibit an increase in alkaline phosphatase-specific activity at 24 h; 4) the effects on this membrane enzyme are comparable in the plasma membranes and matrix vesicles, but the net effect is greater in the extracellular organelle due to the intrinsically higher levels of activity; 5) although differentiation is promoted in resting zone cells, it is limited in the growth zone cells by inhibition of phospholipase A2 activity; and 6) there is a synergistic enhancement of resting zone chondrocyte differentiation when cells are exposed to rhTGF-beta-1 and 24,25-dihydroxyvitamin D3.
Previously we reported a case of persistent hypotension associated with hypermedullipinemia (Blood Pressure 1992; 1:138-148). The hypermedullipinemia appeared to result from the autonomous secretion of medullipin I (Med I) by renomedullary interstitial cells (RIC's) in the patient's remaining endstage kidney. The patient subsequently died. At autopsy, the remaining kidney contained a yellow mass (1 x 1 x 0.5 cm) consisting of adipocytes and RIC's, termed a lipomedullipinoma. This mass was extracted and chromatographed by procedures known to yield Med I. Med I was identified following these procedures. Renal tissue outside the yellow mass failed to yield Med I. It appears that the hypermedullipinemia of this case resulted from autonomous, hypersecretion of Med I by the lipomedullipinoma.
"Shell space" is space constructed to meet future needs; it is space enclosed by an exterior building shell, but otherwise unfinished inside. The construction of shell space at the same time another facility is constructed, while adding to overall immediate construction costs, often can lower total expenditures over the long term. This article presents a model for evaluating the financial feasibility of constructing shell space during a capital construction project.