HIV seroprevalence and antenatal clinics.
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Biomedical subjects
Publications and source records attributed to S Walsh.
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One injection of estradiol benzoate (EB) (100 micrograms) or vehicle was administered to male rat pups 5 days after birth. Two months later ventilation, ventilatory responses to 7% carbon dioxide, and to 580 mg/kg aspartic acid (an agent used as a marker of sexually dimorphism in the control of ventilation) were evaluated and body weight, testes weight, and nose-anus length were measured in animals in each group. The EB-treated rats had similar tidal volumes, frequency of breathing, and minute ventilation as did control male rats. The ventilatory responses of EB-treated rats to hypercapnia were markedly less than those of control animals. Aspartic acid administration depressed ventilation in control animals, but had no effect on ventilation in EB-treated males. Body and testes weights, as well as nose-anus length, were less in EB-treated compared with control rats. However, when body weight was normalized by nose-anus length and testes weight was normalized by body weight, the values were comparable between the two groups. Thus, perinatal EB treatment of male rat pups results in small, hypogonadal adult animals whose ventilation in response to hypercapnia was diminished and whose response to aspartic acid was female-like relative to those of control rats.
BACKGROUND: The electrical current and energy required to terminate ventricular tachyarrhythmias are known to vary by arrhythmia: Ventricular tachycardia (VT) is generally considered to require less energy than ventricular fibrillation (VF). The hypothesis of our study was that current requirements for transthoracic termination of VT are further determined by VT rate and QRS complex morphology. METHODS AND RESULTS: We prospectively studied 203 patients who received a total of 569 shocks for VT or VF by following a current-based protocol. This protocol recommended shocks for VT beginning at 18 A (70 +/- 22 J) and shocks for VF beginning at 25 or 30 A (137 +/- 52 J or 221 +/- 70 J). The ventricular tachyarrhythmias were subclassified as monomorphic VT (MVT): uniform QRS complex morphology on surface electrocardiogram and heart rate greater than 100 beats per minute; polymorphic VT (PVT): nonuniform QRS complex morphology and heart rate less than or equal to 300 beats per minute; or VF: nonuniform QRS complex morphology and heart rate greater than 300 beats per minute. We found that shocks of 18 A and 25 A for terminating MVT had success rates of 69% and 82%, respectively, whereas such low-current shocks were less successful for PVT (33% at 18 A) and for VF (19% at 18 A, 53% at 25 A). High-current shocks of 35 A and 40 A were equally successful for the three ventricular tachyarrhythmias. Subdividing MVT revealed that slower MVT (heart rate less than 200 beats per minute) had a significantly better success rate with low-current shocks of 18 A and 25 A than did faster MVT (greater than 200 beats per minute) (89% versus 72% success, p less than 0.01). Bundle branch block morphology, QRS axis, and duration of ventricular tachyarrhythmia did not alter current requirements. CONCLUSIONS: Heart rate and electrocardiographic degree of organization of ventricular tachycardia are important determinants of transthoracic energy and current requirements for cardioversion and defibrillation. Transthoracic termination of MVT requires relatively low current or energy, but PVT behaves more like VF and requires higher electrical current or energy.
A study of 578 patients treated for colorectal cancer in the North-west region comparing survival after surgery in teaching and non-teaching hospitals was performed. All patients had a minimum of 5 years follow-up. A greater proportion of elderly and emergency patients were treated in the non-teaching hospitals. The number of operative mortalities and 5-year survival figures for all causes of death and for colorectal deaths alone were similar in teaching and non-teaching hospital patients.
This investigation examined the metabolic and cellular effects of immobilization on immature rabbit medial collateral ligaments (MCLs). Thirty-two three-month-old rabbits had their right knee pinned in flexion for intervals of two weeks, one month, two months, or three months before being killed for comparison with MCLs from nonpinned contralateral controls and MCLs from 16 normal age-matched controls. Twelve animals were studied by gait analysis after either one month or three months of immobilization and were killed with the others for in vitro analysis of ligament mass, collagen synthesis, plasminogen activator secretion, or DNA content. Immobilized hindlimbs carried less weight than did contralaterals, and MCLs from those hindlimbs synthesized less collagen and secreted less plasminogen activator than did controls at all intervals. Contralaterals also showed some signs of altered cell metabolism compared with normal controls, suggesting that they are not normal by these assessment criteria. With increasing periods of knee immobilization, immobilized MCLs switched progressively from an anabolic to a more catabolic state, apparently contributing to the failure of immobilized ligaments to increase normally in mass. Knee immobilization alters the metabolic behavior of MCLs in both knees in growing rabbits, and, based on these results, either knee joint motion or hindlimb load bearing could be necessary for normal rabbit medial collateral ligament growth and maturation.
The purposes of this investigation were to examine among a sample of hemiparetic stroke patients the nature and reliability of selected muscle performance measures and the correlation between the measures and gait speed. Fourteen subjects who met specific entry criteria participated. The Lido Active Rehabilitation System was used to obtain bilaterally all muscle performance measures of knee extension (velocity, isometric torque-peak and time specific, and time to peak torque and 90% peak torque). Gait speed was measured under both "comfortable" and "maximum safe" conditions. In addition to lower torques, the subjects demonstrated slower knee extension speeds and longer times to peak torque and 90% peak torque on the paretic than on the nonparetic side. High intrasession reliabilities were demonstrated for all muscle performance measures except the torque at 0.1 sec on the nonparetic side and the time to peak torque and 90% peak torque measures. Significant correlations were demonstrated between both gait speeds and paretic knee extension torque (except at 0.1 sec), nonparetic knee extension torque at 0.1 sec and 0.2 sec, and time to nonparetic peak torque. Muscle performance measures other than peak torque appeared to offer little advantage (alone) over paretic peak torque for predicting gait speed. Over 74% of the variance in gait speed, however, could be predicted by the peak isometric peak torque of the paretic side and the time to peak torque on the nonparetic side, together. Thus, there may be benefits to testing the muscle performance of both lower extremities when examining patients with stroke.
This investigation quantified the alignment of fibrillar matrix in normal rabbit medial collateral ligaments (MCLs) and in healing MCLs from animals treated with or without knee immobilization. Twenty-four immature female rabbits were given complete midsubstance injuries to their right MCLs. Fifteen of them had that knee pin immobilized in flexion, while the remaining nine were allowed unrestricted cage activity. Animals were sacrificed in groups of three at intervals of 3, 6, or 14 weeks after injury, and both healing MCLs and unoperated contralateral controls were fixed in situ for subsequent removal, freeze-fracture, and preparation for scanning electron microscopy (SEM). A random sampling of SEM photographs followed by automated, statistically validated image processing was used to quantify alignment of matrix in all samples. Results showed that nonimmobilized MCL scars in this model do remodel over 14 weeks of healing, returning to normal alignment values in that time. Surprisingly, MCL scars in immobilized knees were even better, with mean matrix alignments falling statistically within normal MCL limits at all healing intervals studied. If not due to an unknown sampling or fixation artifact, these results suggest that gross knee flexion and extension is not a prerequisite for scar matrix alignment in this immature model of ligament healing.
The pharmacokinetics of ampicillin-sulbactam in elderly subjects (65 to 85 years; group 3, n = 8), compared with those in middle-aged (41 to 64 years; group 2, n = 8) and younger (20 to 40 years; group 1, n = 8) subjects, were investigated. A single 2-g dose of ampicillin combined with 1 g of sulbactam in 60 ml of intravenous solution was administered to each subject over a 30-min period. Blood and urine samples were taken at baseline and serially over an 8.5-h period following the infusion. Ampicillin and sulbactam concentrations were assayed by high-performance liquid chromatography on a reversed-phase C-8 column. The mean levels in serum of both ampicillin and sulbactam were significantly higher for samples from group 3: for ampicillin from 1 through 8.5 h, and for sulbactam for the same time interval except at 5.5 h (P less than or equal to 0.05). The mean urinary excretion of both ampicillin and sulbactam was lowest, and urinary concentrations were highest in group 3. The areas under the serum drug concentration-time curve, the half-lives, and the maximum concentrations in serum were greatest, while the total clearance was lowest, for group 3 for both ampicillin and sulbactam. These results are consistent with a prolongation of antimicrobial activity of ampicillin-sulbactam in the elderly compared with that in younger subjects.
Osteoclastoma-derived giant cells were used to produce 11 mouse monoclonal antibodies (MAb) reactive against human osteoclasts on undecalcified sections of adult human bone. All exhibited unique reactivities across a wide range of human tissues. Three in particular demonstrated distinctive reactivities; C35 was highly selective for bone osteoclasts, C27 showed selective reactivity for osteoclasts, tissue macrophages and blood-borne monocytes, and C22 showed selective membrane staining of osteoclasts. Consequently, C22 was used to coat Dynabeads to affinity-purify viable human osteoclasts from osteoclastoma-derived cell suspensions. Immunocytochemical staining of inflammatory osteoarthritic synovium/granulation tissue demonstrated positivity in the majority of giant cells with MAb C22 and C27. In contrast, C35 reacted with only very occasional giant cells. Furthermore, multinucleated cells formed in long-term human bone marrow cultures demonstrated similar selective staining. C27 stained all giant cells and the majority of mononuclear cells. C22 detected only a small proportion of giant cells. In contrast to its staining on bone osteoclasts, C22 demonstrated granular cytoplasmic staining in cultured giant cells. C35 stained no cells at all in these cultures. These MAb can therefore distinguish between giant cells of various origins and authentic mature osteoclasts. Alternatively, they can recognize antigens expressed at different stages of osteoclast differentiation and therefore provide an excellent tool for the study of the human osteoclast lineage.
The purpose of this study was to address the question: Is the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) comparable to the original MMPI in its applicability to the assessment of posttraumatic stress disorder (PTSD) among Vietnam combat veterans? The question was addressed by administering both the original MMPI and MMPI-2 to 29 subjects classified as meeting Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; DSM-III-R) criteria for PTSD and comparing MMPI and MMPI-2 scores in terms of: degree of association, code-type congruence, diagnostic hit rates (when compared to two other clinical samples, and one normal sample), and congruence of the Keane PTSD Scale (PK). Results reveal highly significant correlations between MMPI and MMPI-2 basic scales for the PTSD sample as well as congruence in 2-point codes comparable to previous studies. The MMPI-2 was found to identify effectively PTSD subjects from the other groups. Results also showed a high degree of association between the MMPI and MMPI-2 in regard to PK scores, although minor differences were found in PK raw scores between the two tests. Overall, the findings suggest a high degree of comparability between the MMPI and MMPI-2 in the assessment of PTSD.
Thirteen patients with expansion of an unusual subset of T lymphocytes, defined by large size, cytoplasmic granularity and CD3+ CD8+ Leu 7+ surface phenotype, are reported. Although morphologically and/or phenotypically abnormal lymphocytes were found in all patients, only five had an absolute peripheral blood lymphocytosis. Ten patients had a bone marrow lymphocytosis. As in previous series, there was a strong association with neutropenia (12 patients) and polyarthropathy (seven patients). The latter group displayed a wide range of articular disease: classical or definite rheumatoid arthritis in four patients and milder non-erosive disease in the remainder. All 13 patients showed evidence of abnormal B cell function: IgM rheumatoid factor was present in nine patients, neutrophil-specific antibodies in six and all showed an increased level of at least one immunoglobulin isotype. These patients may be difficult to distinguish from those with idiopathic neutropenia and Felty's syndrome. Such a distinction may not be made on clinical grounds alone: critical assessment of lymphocyte morphology, bone marrow examination and analysis of lymphocyte phenotype should be considered in all patients with unexplained neutropenia, particularly in the context of arthritis. It is suggested that the true prevalence of this syndrome may have been greatly underestimated.
Hydrogen peroxide is associated with the development of cataracts. As an oxidant, it can act on the sulfhydryl groups of proteins and alter the transport properties of membranes. A nearly impermeant sulfhydryl binding agent is p-chloromercuriphenylsulfonate (p-CMPS). The changes in the current-voltage relationship of the equatorial potassium current produced by hydrogen peroxide and p-CMPS are similar. The authors studied the effects of p-CMPS to determine the possible effects of binding extracellular sulfhydryl groups. With a vibrating probe and microelectrodes, the authors saw three sequential effects of 0.5-5.0 microM p-CMPS. The first phase was a shift of the reversal potential, which is equivalent to the potassium equilibrium potential, to more negative values. The current-voltage relationship (J vs PD) shifted in a manner opposite to that produced by ouabain. The 86Rb uptake was stimulated. Ouabain blocked this initial phase. The second phase was a decrease in the resistance. The effects seen were similar to those described in other tissues after the intracellular injection of small amounts of Ca++. This second phase was inhibited by the removal of Ca++ from the medium and also by the addition of quinine to the medium. The third phase consisted of a depolarization of the lens. This effect has been described by others with larger concentrations of p-CMPS and is accompanied by an influx of Na+ and Ca++. The results suggested that micromolar quantities of extracellular p-CMPS sequentially stimulate the Na, K-pump; activate Ca(++)-dependent K+ channels; and open nonspecific channels. It is suggested that the second phase may play a role in cateractogenesis.
Data collected prospectively from 578 patients with colorectal cancer managed by 12 Manchester surgeons were analysed to evaluate the effects on survival of prognostic, clinical and pathological factors. Available preoperative and perioperative factors were included in a stepwise regression analysis and curative resection was found to be most strongly associated with patient survival. Other variables ranked according to their relative importance were performance status, weight loss and sex. The finding of the study supports the need to establish an early diagnosis if long-term survival results are to improve.
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The operative mortality rate after surgery for colorectal carcinoma remains significant. A series of 578 patients has been studied prospectively. The features which most significantly affect operative mortality are the age of the patient, a history of loss of weight, limited preoperative patient mobility and the presence of intestinal obstruction with perforation of the bowel. By identifying high-risk groups of patients, attention may be focused on particular patients at risk, in order to reduce operative mortality.
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The percepts of electrical stimulation of the auditory nerve can best be determined in man. An eight channel bipolar electrode array has been developed which allows discreet stimulation of segments of auditory nerve via the scala tympani. In addition, a programmable stimulator has been developed which allows the delivery of different waveforms and stimulus patterns. Hopefully this will begin to allow the generation of the elements of speech.
Urogastrone, a peptide isolated from human urine, is known to cause inhibition of gastric acid secretion and proliferation of fibroblasts in culture; furthermore immunofluorescent localization techniques show it to be present in submandibular and Brunner's glands. Serum, saliva, and gastric juice samples have now been fractionated upon Sephadex G-200 and G-50 and the immunoreactive urogastrone located using a specific radioimmunoassay. Biologic activity was shown by mitogenic studies with 3T6 fibroblasts. In serum, the major immunoreactive component was ca. 1-2 X 10(5) daltons, but trypsin treatment then gave a smaller biologically active species in the same position as pure urogastrone on Sephadex G-50. Both saliva and gastric juice showed major components at the position defined by urogastrone, and these also stimulated the uptake of [H]thymidine into the fibroblasts. It is concluded that a urogastrone-like molecule can be released enzymically from a high molecular weight serum precursor and that the small biologically active peptide is also a normal component of saliva and gastric juice.