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Biomedical subjects

S Hunter

Publications and source records attributed to S Hunter.

At least 181 records · Page 10Linked to original sources

Experimental allergic encephalomyelitis: clinical disease and enhanced cellular transfer in the absence of lymphocyte proliferative responses against syngeneic MBP.

Experimental allergic encephalomyelitis (EAE) was induced in Lewis rats using several different immunization protocols, and draining lymph node cells from these animals were assayed for proliferation against heterologous, homologous, and syngeneic MBP, and syngeneic spinal cord. Proliferative responses were largely stimulated by nonsyngeneic antigenic determinants and correlated better with the antigen used to induce EAE than with signs of autoimmune disease. Lymph node cells from rats immunized with either guinea pig spinal cord or syngeneic MBP did not proliferate measurably when restimulated in vitro with syngeneic MBP, yet lymphoid cells from these animals were enhanced in their capacity to transfer EAE following in vitro stimulation with syngeneic MBP.

Animals↗

The production of hydroxyl radical by human neutrophils stimulated by arachidonic acid--measurements by ESR spectroscopy.

Human neutrophils incubated with sodium arachidonate generated hydroxyl radicals. The radical formed an adduct with the spin trap 5', 5-dimethyl-l-pyrroline-N-oxide (DMPO) and was subsequently detected by electron spin resonance (ESR) spectroscopy. The ESR signal was inhibited by mannitol and superoxide dismutase but not by catalase. Removal of glucose from the reaction mixture or the presence of glucose metabolic inhibitors including 2-deoxy-D-glucose and 3-O-methyl-D-glucose did not affect the production of hydroxyl radical by the neutrophils. The ESR signal was, however, inhibited by the lipoxygenase inhibitors nordihydroguaiaretic acid and N-ethylmaleimide. The involvement of lipoxygenase in the production of hydroxyl radical was demonstrated by the trapping of the radical with DMPO in a reaction mixture of soybean lipoxygenase and arachidonic acid (AA). These findings support our previous postulation that the metabolism of AA via the lipoxygenase pathway is a source of hydroxyl radical in stimulated neutrophils.

3-O-Methylglucose↗

The metabolic load of stored blood. Implications for major transfusions in infants.

Plasma electrolyte, intermediary metabolite, and hormone concentrations were measured in samples of 110 units of citrate phosphate dextrose blood being used for clinical transfusions. The most important changes from the physiological range were in sodium, potassium, glucose, and lactate concentrations. Mean sodium concentrations fell from 170 mmol/l at the beginning of storage to 156 mmol/l at the end and mean potassium concentrations rose from 7 mmol/l to 25 mmol/l. Glucose had a mean concentration of 20 mmol/l at the beginning of storage and had only fallen to 15 mmol/l at the end. Mean lactate concentrations increased from 7 mmol/l at the beginning of storage to 25 mmol/l at the end. Many samples had cortisol, insulin, and growth hormone concentrations within the physiological range. Citrate phosphate dextrose blood contains a large substrate load that changes during storage and that should be taken into account when infants are transfused large volumes of blood. The strong correlation coefficients with duration of storage for sodium, potassium, and lactate (-0.71, 0.91, and 0.90, respectively) indicate that concentrations of these substrates can be predicted within a narrow range if the duration of blood storage is known.

Blood Glucose↗

A terminal deletion of the long arm of chromosome 4 [46,XX,del(4)(q33)] in an infant with phenotypic features of Williams syndrome.

A female infant with peripheral pulmonary artery stenosis, growth retardation, and developmental delay was noticed to have facial features consistent with a diagnosis of Williams syndrome. Chromosome analysis revealed a deletion of the terminal portion of the long arm of chromosome 4 (4q33----qter). This is the seventh reported case of this chromosome disorder. It is possible that this chromosome region is specific for the Williams syndrome phenotype but it is more likely that the syndrome is heterogeneous. Chromosome analysis should be performed in all suspected cases with particular attention to the long arm of chromosome 4.

Chromosome Deletion↗

Reactive gliosis simulating butterfly glioma: a neuroradiological case study.

Reactive gliosis was found in a 40-year-old man who presented with intractable seizures thought to be due to a malignant neoplasm. Although two separate lesions located bilaterally in the frontal lobes were evident on the computed tomographic scan, a connection between these lesions along the fibers of the corpus callosum was clearly demonstrated on T2-weighted magnetic resonance images. The unusual radiological appearance of this gliosis, which simulated a malignant butterfly glioma on magnetic resonance imaging (MRI), is reported. Because MRI is still a new modality, its images should be interpreted with judicious caution.

Adult↗

Neuropathologic findings in idiopathic opsoclonus and myoclonus. Their similarity to those in paraneoplastic cerebellar cortical degeneration.

The neuropathologic findings in an idiopathic case of the opsoclonus/myoclonus syndrome are reported. Although neurologic dysfunction may have been more widespread, structural lesions were limited to the cerebellum and inferior olives. Severe depletion of Purkinje cells with preservation of granular cells was evident throughout the neo- and paleocerebellum; however, groups of Purkinje cells were preserved in the archicerebellum. No abnormalities were evident in the paramedian pontine reticular formation of the caudal pons. Inflammation and evidence of anoxic damage were absent. These changes are very similar to those described in paraneoplastic cerebellar cortical degeneration.

Cerebellum↗

INTRAV and ORAL: BASIC interactive computer programs for estimating pharmacokinetic parameters.

Two interactive computer programs, INTRAV and ORAL, were written to permit pharmacokinetic modeling of experimental data and to obtain pertinent values based on derived estimates. Both programs utilize BASIC language and were developed on a microcomputer with graphics capability. Drug concentration in blood, plasma, or serum with time following either nonabsorptive (intravenous) or absorptive (oral or intramuscular) administration is input, and a semilogarithmic display of data appears on a cathode-ray tube (CRT). The user selects limits for various linear segments using a movable cursor. On command, coefficients and exponents for the differential equation which describes those limits is computed and a nonlinear curve is fitted through the data set. Results from statistical tests are available in output formats permitting the user to determine the goodness of the selected limits. Commonly used pharmacokinetic parameters are also computed and appear on the output. Numerous graphic output options are also available to permit comparisons between data sets and/or estimates derived from other computer programs. INTRAV and ORAL were compared with the widely used programs CSTRIP, ESTRIP, and NONLIN. Both INTRAV and ORAL gave estimates which were almost identical with CSTRIP and ESTRIP, whereas those obtained with NONLIN were very similar, although not identical.

Computers↗

Nitrogen inhalation in the human.

The neuropathologic findings in the brain of a National Aeronautics and Space Administration (NASA) engineer, who died subsequent to nitrogen inhalation, are reported. Findings which are unusual in other forms of anoxia included relative preservation of neurons in the Sommer sector of the hippocampus and a pattern of damage similar to that of "hypotensive brain stem necrosis" in the cranial nerve nuclei. Some lesions conformed exactly to gray matter structures, whereas others disclosed no respect for anatomic boundaries. Both selective necrosis and relative preservation of neurons were evident in different regions of the brain. Distinct differences between lesions in various areas of the CNS suggest the importance of multiple and complex pathogenetic mechanisms in anoxia caused by exposure to nitrogen.

Brain↗

The rostral mesencephalon in Parkinson's disease and Alzheimer's disease.

The rostal mesencephalon at the level of the posterior commissure was studied by light microscopy in two patients with idiopathic Parkinson's disease, one patient with Alzheimer's disease, and one patient with senile dementia of Alzheimer's type. In the Parkinsonian cases, the rostral part of the nucleus of Edinger Westphal disclosed Lewy bodies in 3% of the neurons, neurofibrillary degeneration in 2% of the neurons, and a 54% neuronal loss. In Alzheimer's disease, 2% of Edinger Westphal neurons contained neurofibrillary degeneration, whereas in senile dementia of Alzheimer's type only rare neurofibrillary degeneration was evident in this nucleus. Neuronal loss was not apparent in the nucleus of Edinger Westphal in either of the Alzheimer's cases. The pathologic changes observed in this presumably cholinergic nucleus resemble in some respects changes reported in the cholinergic centers of the basal forebrain in these diseases. In addition, the central gray matter and pretectal region in Parkinson's disease contained a patchy increase in astroglia, some with scant reactive cell bodies; however, Lewy bodies were limited to that part of the central gray matter corresponding to the nucleus of Darkschewitsch. A few neurofibrillary tangles were present in the nucleus of Darkschewitsch in both diseases.

Adult↗

Discrete sub-aortic stenosis and ventricular septal defect.

We present details of 15 children, aged 3 months to 11 years, with discrete sub-aortic stenosis and ventricular septal defect. We emphasise a high index of clinical suspicion and echocardiography as the best means of diagnosing this dangerous combination. Physical signs were those of ventricular septal defect in all patients, with auscultatory evidence of additional sub-aortic stenosis in only one. Five patients had a short early diastolic murmur of mild aortic incompetence. The electrocardiograph showed isolated left ventricular hypertrophy in eight patients. Cardiac catheterisation and angiography identified the ventricular septal defect in all cases but detected the sub-aortic stenosis in only eight. Cross sectional echocardiography showed both lesions in all 11 patients to whom it was available.

Aortic Stenosis, Subvalvular↗

Role of echocardiography in differential diagnosis of broad complex tachycardia.

It is not always easy to distinguish between supraventricular tachycardia with aberration and ventricular tachycardia by electrocardiographic analysis alone. M mode echocardiography can often help by providing direct or indirect evidence of the relation between atrial and ventricular contraction. Sixteen consecutive patients with spontaneous sustained broad QRS complex tachycardia with heart rates of 120-225 beats/minute were examined. Echocardiographic evidence of 1:1 conduction was seen in three cases and 2:1 atrioventricular conduction in one (all four had supraventricular tachycardia, confirmed by intracardiac electrocardiography in three). Evidence of retrograde block was seen in 12 (all had ventricular tachycardia, with electrophysiological confirmation in 10). Satisfactory views of the mitral valve were obtained in all patients. Patients with ventricular tachycardia had a variable mitral valve opening time (range 42-110%) compared with those who had supraventricular tachycardia (9-15%). Aortic root and left atrial views gave direct evidence of atrial contraction in three cases, and subcostal right atrial wall views were diagnostic in four of five cases. Seven patients with ventricular tachycardia had been wrongly diagnosed elsewhere as having supraventricular tachycardia. This study confirms that echocardiography is a simple and rapid aid to accurate diagnosis in patients with broad QRS complex tachycardia.

Adolescent↗

Psychological factors and outcome of electrode implantation for chronic pain.

The utility of using psychological assessments as a basis for predicting pain relief after electrode implantation is examined. Two raters independently reviewed the functional pain protocols of chronic pain patients who were candidates for deep brain (n = 13) or spinal cord (n = 17) electrode implants and predicted whether each would have a good or poor treatment response. At follow-up, five deep brain (39%) and four spinal cord (24%) patients were classified as having good responses to treatment. Predictions of outcome based on psychological data were accurate for 80% of the patients. These results suggest that functional pain assessment is useful as a part of preimplantation screening and emphasize the importance of psychological factors in the outcome of treatment for chronic pain.

Electrodes, Implanted↗

Monoclonal antibodies to alpha 2u-globulin and immunocytofluorometric analysis of alpha 2u-globulin-synthesizing hepatocytes during androgenic induction and aging.

Stable hybridomas generated by fusion of spleen cells from hyperimmunized mice and mouse myeloma cells were cloned to prepare monoclonal antibodies to alpha 2u-globulin, an androgen-dependent urinary protein of hepatic origin. One of these monoclonal antibodies was used as a probe for immunocytofluorometric analysis of alpha 2u-globulin producing hepatocytes during androgenic induction and aging through fluorescence-activated cell sorting (FACS). FACS patterns of hepatocytes from mature male rats that produce high levels of alpha 2u-globulin showed tow distinct peaks, arbitrarily designated as peak I (weakly fluorescent) and peak II (brightly fluorescent). In the mature male rat, peak II represented about 40% of the total hepatocytes, and the fluorescence intensity of this subpopulation decreased in direct correspondence with the gradual decline of alpha 2u-globulin synthesis during aging. Similarly the androgenic induction of this protein in ovariectomized female rats was associated with an increase in the fluorescence intensity of the hepatocyte subpopulation under peak II rather than an increase in the relative number of these cells. From these results we conclude that the androgen-dependent synthesis of alpha 2u-globulin and its alteration during aging are confined to a specific subpopulation of hepatocytes within the liver.

Aging↗

A rapid procedure for visualising the inner cell mass and trophectoderm nuclei of mouse blastocysts in situ using polynucleotide-specific fluorochromes.

A rapid procedure has been devised to count the numbers of outer trophectoderm (TE) and inner cell mass (ICM) cells of mouse blastocysts by differentially labelling their nuclei in situ with polynucleotide-specific fluorochromes. The TE nuclei were labelled with propidium iodide (PI) by permeabilising the cells using selective antibody-mediated complement lysis (Solter and Knowles, '75). The blastocysts were then fixed in ethanol and the ICM nuclei labelled with bisbenzimide. These two fluorochromes have widely different fluorescent spectra. Thus, by using fluorescence microscopy with appropriate filter combinations, the PI-labelled TE nuclei appeared pink or red; the bisbenzimide-labelled ICM nuclei, blue or unlabelled. The total numbers of blastocyst nuclei and the numbers of ICM nuclei counted by differential labelling were similar to the numbers detected after spreading the nuclei of intact blastocysts or immunosurgically isolated ICMs by air-drying (Tarkowski '66). Differential labelling of TE and ICM nuclei in situ has two important advantages--that the numbers of both these cell types can be determined for individual blastocysts and that spatial relationships are partially preserved so that regional interactions can be studied.

Animals↗

Monoclonal anti-T-cell antibodies react with circulating myeloid leukemia cells and normal tissue macrophages.

Rabbit and monoclonal antibodies to human myeloid leukemia cells, monocytic leukemia cells and human thymocytes have shown the existence of common T-cell/myeloid/monocyte antigens. For this reason, the specificity of a series of monoclonal antibodies to human T-cells (OKT 1, 3, 4, 5, 6, 8, 9, 10; and NA1/34) was tested by immunofluorescence (cytofluorograph) and complement-mediated cytotoxicity against human myeloid leukemia and normal blood cells and leukemic cell lines. In addition, an immunohistological analysis of the specificity of OKT4, 9.3, Leu 3a, OKT3 and NA1/34 antibodies was performed using normal lymphoid tissues and a sensitive immunoperoxidase technique. Normal human peripheral blood mononuclear cells reacted with OKT3 ("pan T-cell", mean 54%), OKT4 ("helper T-cell", mean 35%) and OKT 5/8 ("suppressor T-cell", mean 18%) as previously reported. However, OKT3 reacted with the cell lines K562 (myeloid), RC2a and THP-1 (monocytoid) and U937 (macrophage) as well as with cells from 9/65 myeloid leukemia patients. OKT4 reacted with the cell lines HL60 (promyelocyte), RC2a and U937 and also with cells from 6/60 myeloid leukemia patients. OKT5 reacted with the cell lines K562 and THP-1. OKT1 ("pan T-cell") reacted with THP-1 and with myeloid and monocytic leukemia samples (5/32) as did OKT6 ("cortical thymocyte") (3/32). OKT10 ("common thymocyte") reacted with a range of leukemia cell lines (B-cell, pre- B-cell and macrophage) as well as 7/21 myeloid leukemia samples. In tissue sections Leu 3a, (9.3 and OKT4 to a lesser extent), stained paracortical lymphocytes, plus subcapsular and medullary macrophages, and dendritic cells present within the paracortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗

Anatomical basis of cross sectional echocardiography.

Ten hearts were cut in planes to simulate echocardiographic cuts which may be taken to visualise the anatomy of the cardiac chambers and great arteries. The various myocardial wall segments were named from these sections by referring to their position in the reconstituted heart. The sections were studied in their correct anatomical position. In this way they provide a reference for appropriate orientation of echocardiographic images.

Echocardiography↗