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Biomedical subjects

C M Allen

Publications and source records attributed to C M Allen.

At least 127 records · Page 7Linked to original sources
PubMed1985

An unusual presentation of metastatic carcinoma involving the periodontium.

A case of metastatic nasopharyngeal carcinoma involving the mandibular periodontium of a 36-year-old female is presented. The diffuse gingival enlargement from premolar to premolar was quite unusual, and other conditions were considered in the clinical differential diagnosis. Histopathologic evaluation of the gingival lesion showed a poorly differentiated carcinoma which appeared morphologically similar to earlier metastatic lesions of the nasal fossa and brain.

Adult↗
PubMed1985

Nephrotic syndrome with renal vein thrombosis: pathogenetic importance of a plasmin inhibitor (alpha 2-antiplasmin).

Tests of fibrinolysis were measured by fibrin plate methods in 44 patients with nephrotic syndrome, in 14 of whom renal vein thrombosis was demonstrated. In both groups the level of total fibrinolytic activity was normal, that of vascular plasminogen activator was decreased, and that of an inhibitor of plasminogen activation was elevated. The level of a plasmin inhibitor, measured by the fibrin plate method, was elevated in 13 of 14 patients with, but only in 12 of 30 without, renal vein thrombosis (p less than 0.005). The plasmin inhibitor was identical with alpha 2-antiplasmin. The data suggest that an increased level of alpha 2-antiplasmin may be a factor in determining susceptibility to the development and persistence of renal vein thrombosis in patients with nephrotic syndrome.

Fibrinolysis↗
PubMed1984

Undecaprenyl pyrophosphate synthetase from Lactobacillus plantarum: a dimeric protein.

a++Undecaprenyl pyrophosphate synthetase has been purified from Lactobacillus plantarum. It catalyzes the formation of a C55 polyprenyl pyrophosphate having isoprene residues with cis stereochemistry. The enzyme was shown to be an acidic protein (pI = 5.1), which can be partially purified by preparative gel electrophoresis and Blue-agarose column chromatography. The Km's of the enzyme for its substrates t,t-farnesyl pyrophosphate and isopentenyl pyrophosphate were determined to be 0.13 and 1.92 microM, respectively. The molecular weight of the enzyme was estimated by molecular sieve chromatography and gradient centrifugation to be 56,000 +/- 4000. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the protein was composed of a dimer of 30,000-Da subunits. The enzyme was inactivated by the arginine-specific reagents phenylglyoxal, butanedione and, cyclohexanedione, but this inactivation was not prevented by either of the substrates.

Alkyl and Aryl Transferases↗
PubMed1984

Clinico-anatomical correlations in uncomplicated stroke.

A method for making clinico-anatomical correlations by computer superimposition of brain maps derived from CT scan images, described in a companion paper, was tested in 19 patients with an uncomplicated left hemiparesis due to acute stroke. Eight patients with an isolated left hemiparesis had small lesions in the most rostral part of the right internal capsule. The composite lesion maps of 11 patients whose left hemiparesis was complicated only by spinothalamic sensory loss showed a larger area of damage more caudally in the posterior part of the posterior limb of the capsule, abutting the thalamus. The close correlation between the results obtained by this method and those obtained in previous clinico-pathological studies of patients with uncomplicated strokes, confirms the validity of this mapping technique.

Basal Ganglia↗
PubMed1984

A microcomputer assisted method for obtaining composite pictures of focal brain damage.

A method used to produce composite drawings of superimposed areas of brain infarction is described. The method uses a microcomputer interfaced to a digitising pad and linear plotter. Areas of brain damage are drawn on standardised maps, digitised, manipulated in computer memory, and summated using computer graphics facilities. The composites show the position of brain damage in groups of patients as a contour map of the extent of lesion overlap. The method can be used to study neurological and neuropsychological deficits using CT-scan, or other imaging techniques. Deep and superficial lesions may be displayed equally well.

Cerebral Infarction↗
PubMed1984

Predicting the outcome of acute stroke: a prognostic score.

A prognostic score was derived from a prospective study of 148 consecutively admitted patients, aged less than 76 years, who survived the first 24 hours after an acute stroke. Multivariate analysis was used to compare the presenting clinical features of 137 (93%) of these patients with their outcome after two months. Little change in the level of residual disability was detected in 128 of these patients after a further four months. The features which were found to predict functional dependence or death included older age, complete limb paralysis, depression of conscious level and the combination of hemiplegia and hemianopia with higher cerebral dysfunction. Hemiparesis uncomplicated by hemianopia or higher cerebral dysfunction predicted a return to functional independence. A discriminant function derived from this analysis can be used to calculate the likelihood of recovery to independent function for an individual patient following an acute stroke.

Acute Disease↗
PubMed1984

The acro-osteolysis (Hadju-Cheney) syndrome. Review of the literature and report of a case.

Acro-osteolysis ( Hadju - Cheney ) Syndrome is a rare disorder of bone metabolism characterized by progressive destruction of the distal phalangeal bone, curvature of the spine, aplasia of the facial sinuses, and persistence of the cranial sutures. The purpose of this manuscript is to focus on the description of the oro-facial and dental manifestations of the disorder.

Adult↗
PubMed1984

Predicting recovery after acute stroke.

Patients, relatives, and doctors need to know the prognosis after acute stroke. In recent years, more scientific methods of predicting the level of recovery have become available.

Age Factors↗
PubMed1983

Alcohol use in television programming: effects on children's behavior.

The impact of televised use of alcoholic beverages on children's behavior was evaluated in this study. Children were randomly assigned to one of three experimental conditions: (a) television with drinking depicted, (b) television without drinking, or (c) a no television control condition. Segments of the syndicated television show M.A.S.H. were used as the viewing stimulus. The impact of the various conditions was evaluated in a choice task requiring subjects to choose either martini or regular glasses of either "whiskey" or "water" to serve pictured adults and children. Results indicated that subjects who viewed television drinking were significantly more likely to choose alcoholic beverages for pictured adults but not children. No effect was found for glass preference. Results and implications of these findings and directions for future research are discussed.

Alcohol Drinking↗
PubMed1983

Three models of temporal summation evaluated using normal-hearing and hearing-impaired subjects.

Temporal summation effects were measured in normal-hearing and hearing-impaired subjects using stimuli of different durations and temporal patterns. Threshold decreased with increasing stimulus duration for either single- or multiple-burst stimuli, but the hearing-impaired group showed smaller threshold shifts, which differed from those obtained with the normal-hearing group at the .0001 level of significance. Three models of temporal summation were evaluated: One model employed a time constant in an exponential function, one used a power function characterized by an exponent, and the last combined the properties of the exponential and power functions and was also characterized by an exponent. Estimates of the parameters that best described the data were obtained for each model. Data from the hearing-impaired subjects provided the most critical test of the models. The power function model and the combined model were both satisfactory with the range of stimulus durations used, but the exponential model failed to describe the data from the hearing-impaired subjects. It is suggested that there may not be a decrease in the time constant for temporal summation for subjects with sensorineural hearing-loss, but that a factor related to the utilization of sensory input is altered.

Acoustic Stimulation↗
PubMed1983

Strain-related differences in pathogenicity of Candida albicans for oral mucosa.

Fifty female Sprague-Dawley rats were divided into five groups of 10 animals and were given a low concentration (0.01%) of tetracycline in drinking water. Four of the groups were orally inoculated weekly with the yeast Candida albicans for a period of 25 weeks. Each group received a different strain. Three of the four strains of yeast were consistently recovered upon culture of the oral cavity during the course of the study. Two of the strains produced grossly visible lesions (four of 10 and two of 10 animals) on the midline dorsal tongue, whereas no lesions were seen in the other two experimental groups or the control group. Clinical findings were supported histologically. These data suggest definite strain-related differences in mucosal pathogenicity for the lingual mucosa of rats among the strains of C. albicans studied.

Animals↗
PubMed1983

Clinical diagnosis of the acute stroke syndrome.

To assist physicians without easy access to CT scanning facilities, a scoring system was devised to aid the clinical diagnosis of acute stroke. A consecutive series of 192 patients under 76 years was studied prospectively from admission. The clinical features of 174 (91 per cent) of these patients were compared with their subsequent CT scan or autopsy diagnosis. The scoring system derived from this analysis determines the relative likelihood of infarction or haemorrhage from quantitative assessment of eight clinical variables. Clinical diagnosis with this method was more accurate than the diagnosis made by the patients' physicians. Lumbar puncture performed in 72 patients added little to the accuracy of diagnosis. Nine patients were found to have mass lesions, of whom only one presented with a clear history. Convulsions and neurological deficits which were prolonged or discontinuous in evolution occurred more frequently in patients with mass lesions than in those with vascular lesions.

Acute Disease↗
PubMed1982

Extraction and detergent/lipid activation of dolichol kinase.

The CTP-dependent dolichol kinase from bovine liver microsomes was optimally extracted using either 0.5% sodium deoxycholate or 0.5% Triton X-100 containing 0.5 M NH4Cl. All activity was found in the supernatant fraction following high-speed centrifugation. This fraction was depleted of phospholipid (phospholipid remaining, less than 5% of total) by gel chromatography of the 0.5% deoxycholate extract. This partially purified enzyme was maximally activated 9- or 53-fold over controls in the presence of 0.1% deoxycholate or 0.1% Triton X-100, respectively. Stimulation of the kinase was also observed with mixtures of dimyristoylphosphatidylcholine and deoxycholate. The level of stimulation by these mixtures was up to 20-fold higher than that observed in controls having deoxycholate alone. Dimyristoylphosphatidylcholine alone was not stimulatory. A 1:1 molar ratio of Triton X-100 or deoxycholate to dimyristoylphosphatidylcholine was optimal for enzyme activation. The half-maximum velocity of the dephospholipidated enzyme at 1:1 molar ratio of detergent to dimyristoylphosphatidylcholine was obtained at 150 or 550 microM CTP in the presence of deoxycholate or Triton X-100, respectively. It has been observed, therefore, that dolichol kinase may be extracted from liver microsomes, depleted of endogenous phospholipids and activated by specific molar ratios of detergent to phospholipid.

Animals↗