Search PubMed⌕ Search

Biomedical subjects

M Cooper

Publications and source records attributed to M Cooper.

At least 307 records · Page 17Linked to original sources
PubMed1979

Some properties of 5-hydroxytryptamine receptors in the hindquarters of the rat.

1 The rat hindquarter preparation, as described, responds with reproducible vasoconstriction to noradrenaline and tryptamines. 2 The receptors involved in these responses are distinct. 3 Evidence of heterogeneity of tryptamine receptors was not obtained. 4 The 5-hydroxytryptamine (5-HT) antagonists, methysergide and cyproheptadine, although very potent, displayed antagonism of a non-competitive type whereas a series of phenothiazines and phentolamine displayed competitive antagonism against 5-HT. 5 For the phenothiazines the order of increasing potency was promazine less than chlorpromazine less than triflupromazine.

Animals↗
PubMed1978

Alterations in rat jejunal permeability to a macromolecular tracer during a hyperosmotic load.

The effects of intraluminal hyperosmolality on the intestinal permeability of a macromolecular tracer, horseradish peroxidase, was assessed in rats by light and electron microscopic cytochemistry. After 60 minutes of an intraluminal hypertonic perfusion of 600 mOsM mannitol, horseradish peroxidase was demonstrable in the intercellular spaces between adjacent absorptive epithelial cells of jejunal villi, along the microvillar brush border, in numerous pinocytotic vesicles, in multivesicular bodies, as well as in large lysosomes. Horseradish peroxidase was frequently found extending from the luminal surface of the cell through the tight junctional region and into more basal portions of the intercellular space. In occasional cells, fragments of the interdigitating plasma membranes of two adjacent absorptive cells appeared to bud off into the cytoplasm of one cell. In contrast, after 60 minutes of isotonic perfusion, horseradish peroxidase was confined to the microvillar brush border, a few pinocytotic vesicles, and occasional multivesicular bodies. These experiments suggest that the passage of macromolecules across the jejunal epithelium of adult rats is enhanced under conditions of luminal hyperosmotic stress. This may be due to an alteration in the functional integrity of the tight junctional macromolecular barrier or to an enhanced rate of pinocytosis.

Animals↗
PubMed1977

Pancreatic cancer screening. Analysis of the problem and the role of radionuclide imaging.

The clinical, surgical, and pathologic findings in a five year prospective study of 192 patients referred with a high probability of pancreatic cancer are reported. We have defined the requirements of any pancreatic imaging procedure as its ability to distinguish a normal pancreas from pancreatic cancer or chronic pancreatitis and the capability of detecting tumors less than 5 cm in diameter. There was a 47 percent incidence of pancreatic disease (27 percent pancreatic cancer and 20 percent chronic pancreatitis). Prospective radionuclide imaging as routinely performed was found to be of little clinical value in this patient population; it was neither specific nor sensitive to pancreatic cancer or chronic pancreatitis. Preliminary data with longitudinal multiplane emission tomography show an improved diagnostic accuracy and the ability to detect resectable tumors, but its efficacy needs to be prospectively compared with other screening tests on a carefully defined patient population.

Adenoma↗
PubMed1977

Relationships between psychological differentiation and Cattell's personality traits.

It was hypothesized that individuals who are field-dependent are discriminated from those who are field-independent by Cattell's personality factor A, F, and Q2. A sample of adults (N=68 male and female graduate students) was tested by means of Oltman's Portable Rod-and-Frame Test, field-dependence groups thus being established. Cattell's Sixteen Personality Factor Questionnaire was then administered to the sample. Discriminant analysis of the data resulted in the research hypothesis being supported. Thus, the hypothesized theoretical link between Witkin's psychological differentiation personality dimension and certain Cattellian personality factors was supported empirically. An exploratory stepwise analysis indicated that the Cattellian factors A, L, O, and M may also form a discriminant function which distinguishes between the two groups.

Cattell Personality Factor Questionnaire↗
PubMed1977

Technetium-99m-labeled n-(2,6-dimethylphenylcarbamoylmethyl) iminodiacetic acid (tc-99m HIDA): a new radiopharmaceutical for hepatobiliary imaging studies.

An easily formulated, stable kit preparation of technetium-99m HIDA, suitable for use in humans, was developed and tested in mice and dogs. The tracer was cleared rapidly from the blood and excreted predominantly by the liver in both species. In dogs, the hepatobiliary clearance of Tc-99m HIDA was significantly greater than that of C-14 HIDA and Sn-113 HIDA. The LD50 for HIDA in mice, 168 mg/kg, exceeded the average human dose by a factor of 1000 on a per-weight basis. Blood clearance curves for Tc-99m HIDA in 12 normal subjects were biexponential with half-times of 4.6 +/- 1.0 min and 31.5 +/- 7.0 min, and cumulative 90-min urine samples contained 14.2 +/- 1.8% of the injected dose. Images in normal subjects and nonjaundiced patients showed rapid concentration of tracer by the liver and activity was present within the biliary system in 10-20 min. In jaundiced patients, the tracer blood clearance was delayed and urinary excretion increased, but intestinal activity, indicating biliary patency, was imaged in those patients without complete focal obstruction of the common duct. Technetium-99m HIDA is a nontoxic radiopharmaceutical useful for clinical evaluation of hepatobiliary disorders in humans.

Acetanilides↗
PubMed1976

Diagnosis of Meckel diverticulum by sodium pertechnetate Tc 99m scan.

Meckel diverticulum was diagnosed preoperatively as the cause of recurrent rectal bleeding in a 2-year-old child by means of a sodium pertechnetate Tc 99m scan. Although false-negative scans have been reported to occur in approximately 50% of all cases of Meckel diverticulum, the procedure should be considered in any case of unexplained, painless rectal bleeding, especially in pediatric patients.

Hemorrhage↗
PubMed1976

Menstrual function in Turner's syndrome.

This report describes 2 patients with menstrual dysfunction associated with a 45,X0 karotype. One patient had 2 pregnancies before becoming oligomenorrheic. The other had dysfunctional uterine bleeding associated with excessive estrogen production by her streak gonads.

Adolescent↗
PubMed1976

Development of new radiopharmaceuticals based on N-substitution of iminodiacetic acid.

A new approach to radiopharmaceutical design is demonstrated, in which small chelating groups capable of binding gamma-emitting radiometals are attached to biologically active molecules, thus producing radiopharmaceuticals based on bifunctional drug and biochemical analogs. The chelating group iminodiacetic acid has been evaluated for this role by examining two N-substituted iminodiacetic acids: methyliminodiacetic acid (MIDA) and N-(2,6-dimethylphenylcarbamoylmethyl)iminodiacetic acid (HIDA). Radiochemical and biologic studies showed that both agents were obtained in high radiochemical purity, were stable in vitro and in vivo, and possessed biologic distributions governed almost exclusively by the N-substituted group. These characteristics of 99mTc-labeled N-substituted iminodiacetic acids, prepared using an "instant kit" method, provide the basis for a valuable new class of radiopharmaceuticals based on bifunctional drug and biochemical analogs.

Animals↗
PubMed1976

Automatic quantitative radiometric assay of bacterial metabolism.

In a two-compartment scintillation vial, suspensions of bacteria were cultured with 1 muCi of [U-14C] glucose and the released 14C02 was measured continuously, cumulatively, and automatically in a liquid-scintillation counter modified to maintain sample temperature at 37 degrees C. We could follow the metabolism of bacterial populations through their early phase of exponential growth with good precision. The data were obtained conveniently, with use of conventional reagents, glassware, and counting equipment. From analysis of the exponential portion of the curves for cumulative activity vs. time, we could measure cell replication rate precisely in units of time. The resulting values were demonstrably independent of some common experimental variables, including the number of bacteria in the inoculum and counting system sensitivity. Sensitivity of the bacteria to antibiotics was measured to within a few percent by noting the relative prolongation of replication time in the presence of those inhibitors. The digital data from the scintillation counter are susceptible to on- or off-line computer analysis, thus providing the prospect for a totally-automated analytical system. The method shows promise for the mechanized quantitative analysis of bacterial growth, and its inhibition.

Anti-Bacterial Agents↗