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Biomedical subjects

S Howe

Publications and source records attributed to S Howe.

At least 37 records · Page 2Linked to original sources
PubMed1996

Treatment of recurrent vesicourethral anastomotic stricture after radical prostatectomy with endourethroplasty.

We report our experience with successful treatment of 2 cases of severe recurrent vesicourethral anastomotic stricture after radical prostatectomy with endourethroplasty. Both patients had multiple failures of conventional treatments but have been free of stricture recurrence after endourethroplasty with 11 and 25 months follow-up, respectively. Follow-up urethroscopy showed open anastomotic segments with epithelialization after endourethroplasty in both patients. The patient who was continent prior to endourethroplasty remained continent afterward.

Aged↗
PubMed1994

Evaluation of the Roche Cobas Argos 5Diff automated haematology analyser with comparison to a Coulter STKS.

The performance of the Roche Cobas Argos 5Diff (Argos) automated haematology analyser was evaluated by comparison to manual blood film examination and a Coulter STKS (STKS) analyser. The Argos demonstrated excellent between and inter-batch imprecision for all parameters, except the MCHC, and good linearity for Hb, WBC and platelet count (PLT). After an initial fall the PLT, results were stable for up to six h at 18 degrees C in EDTA(K3) after which an increasing proportion of cells were classified as lymphocytes. Results of 239 patient samples analysed on both instruments, compared by linear regression, gave excellent correlation (r2 > 0.90) for most parameters with the exceptions of the MCHC (0.317), eosinophils% (0.756), monocytes% (0.48) and basophils% (0.002). 'Flagging' of cellular abnormalities by the Argos resulted in excellent sensitivity (97.5%), specificity (93.2%) and efficiency/agreement (93.2%), with fewer false positive and negative results than the STKS, although these differences were not statistically significant. The performance characteristics of the Argos were comparable to those of the STKS with a possible improvement in its flagging abilities.

Autoanalysis↗
PubMed1994

Antimyenteric neuronal antibodies in scleroderma.

The pathogenesis of gastrointestinal (GI) dysmotility in scleroderma is incompletely understood, although previous studies have proposed a neuropathic mechanism. We studied patients with scleroderma as compared with other connective tissue disease patients and normal controls for the presence of circulating antibodies to myenteric neurons. Serial dilutions of sera were overlaid on rat intestine, double-labeled with antineurofilament antibody as a myenteric plexus marker, and imaged using indirect immunofluorescence techniques. High titer sera (> or = 1:50) from 19 out of 41 scleroderma patients stained myenteric neurons, whereas none of 22 normals or 5 patients with idiopathic GI dysmotility were positive. Although 6 out of 20 SLE and 6 out of 10 mixed connective tissue disease patients' sera stained myenteric plexus neurons, when positive sera were absorbed with calf thymus extract to remove antinuclear antibody, 15 scleroderma sera, 0 SLE, and 2 mixed connective tissue disease patients retained positive staining of myenteric neurons. Western blotting using actin and neuronal intermediate filament preparations failed to show immunoreactivity with scleroderma sera containing antimyenteric neuronal antibodies. Paraneoplastic sera associated with GI dysmotility stained myenteric neurons in a different pattern than seen with scleroderma sera. A positive correlation between the presence of Raynaud's phenomenon and antimyenteric neuronal antibodies was observed in scleroderma patients. Our results indicate that IgG antibodies reacting with myenteric neurons are present in many patients with scleroderma. Although the neuronal antigen has not yet been identified, the presence of myenteric neuronal antibodies in patients with GI dysmotility and scleroderma suggests a neuropathic process.

Adolescent↗
PubMed1994

Arterial oxygen tension of patients with abnormal lungs treated with hyperbaric oxygen is greater than predicted.

The arterial oxygen (O2) tension (PaO2) of patients with normal gas exchange treated with hyperbaric oxygen (HBO2) can be predicted from their pre-HBO2 arterial to alveolar O2 tension ratio (a/A) which remains constant up to a PaO2 of 2,000 mm Hg. We observed that the a/A could not be used to predict the PaO2 of patients with impaired gas exchange (reduced pre-HBO2 a/As) treated with HBO2. Our study provides information about the PaO2 of patients with abnormal lungs treated with HBO2. For clinical reasons, we measured the PaO2 of 24 patients treated with HBO2. We obtained arterial blood gas values from patients with lung dysfunction (a/A < 0.75) prior to, during, and after HBO2. The pre-HBO2 a/A = 0.45 +/- 0.17 (mean +/- 1 SD). During HBO2 the a/A ranged from 0.7 to 0.8 depending on chamber pressure and returned to the pre-HBO2 baseline after HBO2. We conclude the following: (1) The hyperbaric PaO2s of patients with a/A < 0.75 is greater than expected. (2) However, the PaO2 is lower than in patients with normal lung function (a/A > 0.75). Possible explanations include improvement in ventilation/perfusion matching, reduction of venous admixture, and/or extra-alveolar uptake of O2. (3) Exposures to HBO2 treatment pressures greater than recommended by existing protocols may be required in patients with impaired transfer of O2 across the lung to achieve PaO2s similar to patients with normal lung function treated with HBO2.

Adult↗
PubMed1992

Normobaric measurement of arterial oxygen tension in subjects exposed to hyperbaric oxygen.

This study demonstrates the ability of an automated blood gas analyzer (Radiometer ABL 330) operated at atmospheric pressure to measure the arterial oxygen tension (PaO2) of ten healthy volunteers exposed to hyperbaric oxygen (HBO2) up to 3.0 atmospheres absolute. Arterial blood samples were aspirated from subjects compressed in a single-person hyperbaric chamber and were analyzed immediately in the blood gas analyzer. The subjects' values for PaO2 correlated with the calculated alveolar O2 tension (PAO2) (measured PaO2 = 0.827 x PAO2-15.1) (r2 = 0.97). Tonometric experiments indicated a difference between saline and blood PO2 measurements. We therefore derived a correction factor for blood measurements (corrected PaO2 = 0.908 x PAO2-52.4) (r2 = 0.98). These results compared favorably with PaO2 measurements made with blood gas analyzers calibrated inside walk-in hyperbaric chambers. We conclude that the PaO2 of normal subjects exposed to HBO2 can be measured accurately at atmospheric pressure with this automated blood gas analyzer. Prior to this study, hyperbaric PaO2 measurements could only be performed within walk-in chambers. Our observations generalize the normobaric measurement of hyperbaric PaO2 to patients treated in single-person and walk-in chambers.

Adult↗
PubMed1991

Development of a disability measurement tool for juvenile rheumatoid arthritis. The Juvenile Arthritis Functional Assessment Report for Children and their Parents.

Two questionnaires were developed for measuring disability due to juvenile rheumatoid arthritis (JRA), one based on patient reports and one on parent reports. These questionnaires were termed the Juvenile Arthritis Functional Assessment Report for Children (JAFAR-C) and for Parents (JAFAR-P). The questionnaires were administered to 72 JRA patients ages 7-18 years and to their parents. Respondents rated the patient's recent ability to perform 23 activities. Patient reports and parent reports were found to correlate highly with each other and with an objective assessment performed by therapists. Questionnaire scores did not correlate significantly with the age of the patient. The JAFAR appears to be a convenient, reliable, and valid measure of disability in patients with JRA.

Adolescent↗
PubMed1991

Noninvasive Doppler blood pressure monitoring in the monoplace hyperbaric chamber.

We describe a noninvasive method of monitoring blood pressure in the monoplace hyperbaric chamber. A standard blood pressure cuff was placed on the patient's arm. A Doppler probe, linked to an ultrasonic Doppler flow detector outside the chamber, was secured over the patient's radial artery. Cuff inflation tubing and the Doppler probe wires were passed into the chamber by modifying a standard disposable hyperbaric intravenous pass-through. Blood pressure readings were determined by inflating and slowly deflating the cuff from outside the chamber while observing the sphygmomanometer within the chamber and listening for the first audible flow signal from the Doppler detector, corresponding to the systolic blood pressure. To minimize the risk of fire in the oxygen-filled monoplace hyperbaric chamber, the patient, Doppler detector, and chamber were grounded. Doppler readings obtained from nine normal subjects whose arterial pressures were being measured with indwelling radial arterial catheters (approved as part of another study by the hospital's Investigational Review Board) compare closely with the subject's blood pressures measured with this noninvasive method: 114 +/- 7.6 mm Hg (mean +/- 1 SD) compared to 112 +/- 8.1 mm Hg, respectively (n = 92 measurements in 8 subjects). We conclude that this noninvasive method of monitoring blood pressure within the monoplace hyperbaric chamber is accurate and suitable for monoplace clinical purposes.

Blood Pressure↗
PubMed1991

Mast cells in the female genital tract.

Mast cells in the human uterus and adnexa have been studied using basic lead acetate fixation and a long toluidine-blue technique to maximise the numbers of cells stained. Counts were performed on measured areas of tissue and the numbers of mast cells related to clinical and pathologic variables. Considerable variation in numbers was found among individual cases at all the sites studied. In the endometrium and myometrium, a drop in the number of mast cells has been demonstrated with advancing age, particularly after menopause. In leiomyomas the highest counts were in the smaller and more cellular lesions. It is concluded that the numbers of mast cells are at least partly related to the degree of cellularity or atrophy of the surrounding tissues. No significant association was found with menorrhagia or with the presence of leiomyomas.

Adnexa Uteri↗
PubMed1989

Development of a disability measurement tool for juvenile rheumatoid arthritis. The Juvenile Arthritis Functional Assessment Scale.

A disability assessment tool, the Juvenile Arthritis Functional Assessment Scale, was developed for, and validated in, patients with juvenile rheumatoid arthritis (JRA). Standards for this 10-item tool were developed using the scores of 63 normal school children as controls and comparing these results with those of 71 age-matched JRA patients (age 7-16 years). The JRA patients scored statistically significantly higher on the scale, which also demonstrated excellent internal and convergent validity and internal reliability. The test is easily administered in 10 minutes by a physical or occupational therapist in a clinical or office setting. This tool represents the first normalized disability assessment tool developed for JRA patients.

Adolescent↗
PubMed1989

Liver cell rosettes: structural differences in cholestasis and hepatitis.

Cholestatic and hepatitic liver cell rosettes, gland-like formations found respectively in chronic cholestasis and in chronic active hepatitis, represent structural modifications of liver cell plates in response to injury. Differences in cytokeratin expression, ultrastructure and three-dimensional (3-D) configuration have been investigated. Cholestatic rosettes are considered to be a form of biliary metaplasia of hepatocytes, linking with newly-formed bile ductules in adjacent septa and probably providing some protection from injury caused by abnormal bile constituents. Hepatitis rosettes, by contrast, are a form of liver cell regeneration developing in isolated surviving hepatocytes or small groups of hepatocytes within areas of collapse.

Bile Canaliculi↗
PubMed1989

Repopulation of guinea-pig skin by melanocytes during wound healing: a morphometric study.

Epidermal keratinocytes and melanocytes have a close functional interrelationship. In order to study this relationship we used computer-assisted three-dimensional morphometry (CAM) to investigate the shape and size changes of the cutaneous melanocyte in healing guinea-pig skin. The combination of CAM with osmium iodide staining and resin embedding of tissue gave excellent results and allowed qualitative and quantitative morphometric assessment of melanocytes in vertical epidermal sections. The changes in melanocytes and keratinocytes during healing of a standard 1 cm full thickness wound in the guinea-pig were studied. After an initial decrease, more melanocytes per mm2 of epidermis were seen (from 36 days). These were smaller in volume with shorter, less branched dendrites compared to controls. An unexpected finding was a late phase of melanocyte proliferation, at the end of our study period (99 days). Clearly, the complex changes in the melanocyte-keratinocyte relationship during wound healing continue throughout and beyond the period of our study.

Animals↗
PubMed1988

Mast cell numbers in appendices with threadworm infestation.

A study has been made of mast cells (MC) in surgically resected appendices using a long toluidine blue (LTB) staining method. The numbers of MC in measured areas of both mucosa and submucosa/muscularis were counted and comparisons made between 22 appendices containing threadworms and 22 which were histologically normal. There was considerable variation in MC numbers from case to case and the patients aged under 15 as a group had a higher mean number of mucosal MC than the older patients. The reasons for the high individual variation could not be identified from the histological sections, and no correlation was found between MC numbers and the presence of threadworms.

Adolescent↗
PubMed1988

The mast cells of the human uterus.

Staining of mast cells in the human uterus has been studied using four fixatives and five staining methods to determine whether there are subpopulations of mucosal (endometrial) and connective tissue (myometrial) mast cells, and to discover how they can best be demonstrated. Following formalin fixation none of the staining methods showed maximum staining of mast cells in either endometrium or myometrium. The best demonstration of uterine mast cells is by fixation with either isotonic formol acetic acid or Mota's basic lead acetate followed by staining with the long toluidine blue technique. Although the degree of MC understaining following formalin fixation was greater for the endometrium than for the myometrium this is inadequate evidence to designate two cell populations. The findings suggest that the mast cells of the human uterus are all one population but show heterogeneity of histological properties possibly related to their functional state.

Adult↗
PubMed1987

Three-dimensional reconstruction of biliary pathways in primary biliary cirrhosis: a computer-assisted study.

Bile ducts and ductules were traced by means of computerized three-dimensional reconstruction in seven patients with primary biliary cirrhosis, three of them in the early asymptomatic stage and four of them with late disease. A patient with cryptogenic cirrhosis was also studied. Loss of bile ducts was confirmed, and was greater in the late stages as expected. Reconstruction demonstrated amputation of bile ducts of various sizes ranging from less than 40 micron to more than 80 micron in external diameter. Amputation was sometimes seen in relation to granuloma formation. The main or side branches of ducts could be traced to zones of proliferated ductules which, in turn, often communicated with liver-cell plates. Clusters of atypical ductules could be seen to communicate with liver-cell plates but not with ductules and ducts. We concluded that proliferation of 'typical' ductules with well-defined lumens, characteristically seen in primary biliary cirrhosis, probably represents a means whereby bile continues to be drained from the liver in spite of interruption of ducts. Computerized three-dimensional reconstruction proved to be a rapid and accurate way of accumulating the necessary data.

Bile Ducts, Intrahepatic↗
PubMed1987

Effects of hypoxia and hypercapnia on VT, f, and VI of nestling and adult bank swallows.

The effects of hypoxia, hypercapnia, and hypoxic hypercapnia on ventilation, and breathing pattern in adult and nestling bank swallows (Riparia riparia) were assessed. The CO2 threshold above which inhaled minute volume (VI) increased significantly in adults and nestlings was 0.045. At each level of fractional concentration of inspired CO2 (FICO2), ventilation in nestlings was lower than that in adults. At a FICO2 of 0.09, VI of adults increased by 284%, whereas VI in nestlings changed 238%. Adult bank swallows also showed a blunted ventilatory response to hypoxia, and the nestling's response was similar to other birds. Adults exhibited greater changes in VI at all levels of hypoxic hypercapnia compared with nestlings. Combined hypoxic and hypercapnic stimuli had an additive effect on ventilation in both groups. Chronic exposure of nestlings to the hypercapnia and hypoxia within burrows seems to significantly alter their ventilatory response to these respiratory stimuli.

Animals↗
PubMed1986

Variation in the argyrophil cell population of the rectum in ulcerative colitis and adenocarcinoma.

Longstanding ulcerative colitis predisposes to carcinoma of the colon. Argyrophil cell hyperplasia has been observed in association with dysplasia and neoplasia in ulcerative colitis. As the argyrophil cell population includes those cells producing enterglucagon, a hormone thought to stimulate mucosal proliferation, this study was designed to determine whether there was any consistent variation in the argyrophil cell population in longstanding ulcerative colitis. Argyrophil cells were demonstrated by the Grimelius method of silver impregnation in sections of non-tumour bearing mucosa from the rectosigmoid colon of normal bowel, ulcerative colitis with and without tumour, and mucosa adjacent to, and distant from, carcinoma arising in otherwise normal bowel. Cell numbers were expressed as ratios of argyrophil cells per crypt, per mm of epithelium, and per mm of underlying muscularis mucosae. There was marked individual variation within all groups in all parameters. Between groups, the only significant difference was an increase in argyrophil cells per crypt in ulcerative colitis. The significance of this finding is discussed.

Adenocarcinoma↗
PubMed1984

Knowledge, attitudes, and practice regarding vasectomy among residents of Hamilton County, Ohio, 1980.

A telephone survey of 1,172 Hamilton County, Ohio residents indicated that for ever-married people, 25.1 per cent of those aged 18-45 and 33.8 per cent of those 30-45 had been sterilized. Blacks and Whites had comparable levels of sterilization but, among Blacks, female sterilization was over eight times as common as vasectomy, while for Whites, the ratio was 1.2. Catholics had only one-half the sterilization rate of Protestants. Race, sex, income, and education were all related to knowledge and attitudes toward vasectomy. The need for more information was a major reason cited for not having a vasectomy.

Adolescent↗