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Biomedical subjects

W Cohen

Publications and source records attributed to W Cohen.

At least 55 records · Page 3Linked to original sources

Composition of high density lipoproteins in rats fed various dietary fibers.

Several studies have suggested that dietary fibers, especially water-soluble sources, are effective agents for lowering plasma cholesterol. This study was undertaken to determine the effect of various fibers on the composition of apoproteins in high density lipoproteins. Rats were fed experimental diets that contained either 20% wheat bran, oat bran or cellulose or 5% pectin or guar gum for 4 weeks. Final body weight was similar among groups. HDL cholesterol and total apoprotein concentrations were not significantly altered by diet. The percentage of apo A-I was significantly elevated and apo E and the apo C's were significantly lower in the guar gum group relative to the wheat bran group. Lecithin cholesterol acyl transferase activity and the C-II-to-C-III ratio were highest in the guar gum group. Differences in the absorption and subsequent metabolism of lipid could account for differences in HDL composition.

Animals↗

Evaluation of cervical spinal cord injuries with metrizamide myelography-CT scanning.

In the past, patients with injuries of the cervical spine and spinal cord have been diagnosed by means of myelography and polytomography. In an attempt to improve the radiographic evaluation of patients with cervical spinal cord injuries the authors performed computerized tomography (CT) scanning of the cervical spine following injection of metrizamide into the spinal subarachnoid space. In 23 patients with cervical spinal cord injuries, metrizamide myelography was performed via a C1-2 puncture. Myelography was used only for localization of the lesion and to determine the site of CT scanning. After myelography, CT scanning of the cervical spine in the transaxial plane was effective in determining the exact nature of compressive lesions and distinguishing the etiology among hematoma, disc, bone fragments, osteophytes, or ossification of the posterior longitudinal ligament. In several patients, metrizamide could be seen entering the spinal cord and was indicative of anatomical spinal cord disruption. In patients with fractures, CT scanning identified the site and nature of the injury without the need for turning the patient to the lateral position. In several patients with an apparently stable cervical spine, the CT scan showed apophyseal joint widening indicative of instability. The authors conclude that CT scanning of the cervical spine after the introduction of metrizamide into the subarachnoid space provides a definitive evaluation of the cervical spinal cord, the bone structures of the cervical spine, and their relationship to each other.

Adolescent↗

The use of ultrasound in evaluating problems and complications of genetic amniocentesis.

A prospective study of 460 midtrimester amniocenteses performed with ultrasonic guidance was made to determine the problems that occur during amniocentesis and the causes of dry or bloody taps. In 27 instances the needle was seen piercing the fetus. Thickening of the uterine wall, tenting of the membranes, and blocking of flow by the fetus were also observed. The dangers of advancing the needle blindly when no fluid is obtained at the predetermined depth is stressed. The use of active real-time ultrasonic guidance during amniocentesis is advocated.

Amniocentesis↗

An automated motion measurement system for clinical gait analysis.

An automated motion measurement system using a television camera interfaced to a computer was constructed and evaluated to determine its applicability to clinical gait analysis. Experimental data indicate that the motion measurement system has a resolution of 1 part in 2000 and a static accuracy of 1 part in 1000 with a worst case dynamic error of 1 part in 300. The study has also shown that this system can reliably track multiple passive markers on a human illuminated with infrared light emitting diodes. This approach minimizes patient distraction, since the illumination is not visible, and reduces patient discomfort since a marker telemetry back pack system, to control active markers, is not needed. Further, the motion measurement system has been successfully demonstrated under conditions similar to those expected in a clinical environment.

Adult↗

[Infantile rumination].

In a 3-month-old baby with recurrent vomiting, infantile rumination syndrome was diagnosed on the basis of the typical behavior, absence of any physical or radiological findings and failure of pharmacological treatment. The therapeutic approach, which consisted of daily visits to the clinic by the mother and effective psychological support by the pediatrician and the nurses, caused prompt improvement and indicated the importance of diagnosis and treatment in the ambulatory clinic.

Ambulatory Care↗

Comparison of infrared and wet chemical analysis of urinary tract calculi.

Infrared analysis of urinary tract calculi using the system of interpretation of spectra of Oliver and Sweet [1] was compared with qualitative wet chemical analysis. This method of interpretation could be learned quickly and gave reproducible results, but had some limitations. Advantages of the infrared procedure include greater reproducibility. 1-mg sample size, greater sensitivity for oxalate and more uniform sensitivities. Minimum detectable amounts of reference standards varied roughly within 1 order of magnitude, compared with a range of 10(5) for wet chemical procedures. The comparable sensitivity for oxalate and phosphate permits a semi-quantitative approach for infrared. The main problems relate to the detection of magnesium ammonium phosphate and carbonate apatite, and wet chemical tests are recommended in addition, when these compounds are suggested. Calculi from 308 patients were analyzed by infrared. With this system of interpretation of spectra, infrared is considered to be a major advance in methodology for analysis of urinary tract calculi in the clinical laboratory, compared with qualitative wet chemical procedures.

Calcium↗

Amniotic fluid cortisol after premature rupture of membranes.

Total amniotic fluid cortisol concentration was studied in 12 patients at 24 to 34 weeks of gestation after premature rupture of membranes of one to eight days duration. Rupture of the membranes of less than 24 hours duration was associated with normal amniotic fluid cortisol concentrations. Rupture of membranes for more than 24 hours was associated in 10 of 12 patients with higher than normal amniotic fluid cortisol levels. The rise in amniotic fluid cortisol concentrations following premature rupture of the membranes may reflect increased fetal or maternal cortisol production or both, and could explain enhanced lung maturation in such infants.

Amniotic Fluid↗