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Biomedical subjects

E Kaplan

Publications and source records attributed to E Kaplan.

At least 217 records · Page 12Linked to original sources

Utilization of diagnostic radiologic examinations in the emergency department of a teaching hospital.

A study to document the utilization by house officers of the Diagnostic Radiologic Examination (DRE) in trauma patients was carried out over 2 years at Stanford University Medical Center. Physicians recorded the likelihood of a fracture being present for patients requiring DRE's to evaluate traumatic injuries. The physician's opinion and the radiologist's final interpretation of the DRE were compared for 24 anatomic regions. Preliminary findings reveal: for almost half the DRE's the officer indicated that the reason for the DRE was medicolegal; 7% of the medicolegal cases had fractures present; less than 4% of these fractures was important enough to change the medical treatment. The levels of house officer experience are suggested as possible causes of excessive DRE utilization, as well as the influence of defensive medicine. Using Green and Swets' Theory of Signal Detection, it is possible to mathematically describe an accuracy index, and a "fear" index for each physician. We plan to use this model in analysis of the study data.

California↗

[Unusual autoimmune and neoplastic associated diseases in Sjogren's syndrome].

In an unselected series of 12 patients with Sjögren's syndrome the following autoimmune diseases were observed: severe myxedema due to Hashimotos thyroiditis in four, subclinical thyroid hypofunction in one, diffuse hyperthyroidism in one, glomerulonephritis in two, chronic active hepatitis in one, lupus erythematodes disseminatus in three (one with idiopathic thrombocytopenic purpura), classical rheumatoid arthritis in two. A rare familial occurrence was seen in two sisters. The only male in this group exhibited coexistence of a benign adenolymphoma of the parotid gland (Warthin's tumor) with a malignant non-Hodgkin lymphoma.

Adult↗

Use of a glucose controlled insulin infusion system (artificial beta cell) to control diabetes during surgery.

An artificial beta cell has been used to achieve and maintain a preset plasma glucose concentration in five diabetic patients undergoing surgery. These subjects were compared to control groups of normal subjects receiving either saline or glucose, and diabetics receiving glucose intraoperatively. Hyperglycaemia during surgery was seen in normals (mean plasma glucose +/- SEM: 185 +/- 16 mg/dl) and, to a greater degree, diabetics (247 +/- 36 mg/dl) receiving glucose. Insulin and C-peptide levels did not increase during 2 hours of operation in any of the control groups, suggesting beta cell suppression during surgery. As C-peptide levels declined similarly in normal subjects whether they received saline or glucose, the hyperglycaemia seems to be due to an inability to use exogenous glucose. This is confirmed by a correlation of maximal plasma glucose to glucose infusion rate (r = 0.78, p less than 0.01). The artificial beta cell was able to achieve the same plasma glucose after 2 hours of operation (128 +/- 21 mg/dl) as normal subjects receiving saline (110 +/- 7 mg/dl). The artificial beta cell proved to be a safe, convenient and effective way of monitoring and controlling the hyperglycaemia seen in diabetic patients undergoing surgery.

Blood Glucose↗

Instrumental analysis of trace elements in thumbnails of human subjects.

Human thumbnails were analyzed for trace elements by instrumental analysis using thermal neutron activation technique. The average concentration of metals studied in clinically symptom-free adult female and male subjects were: zinc, 184 vs. 153 ppm; chromium, 6.8 vs. 4.2; selenium, 0.9 vs. 0.6; gold, 2.6 vs. 0.4; mercury, 1.9 vs. 0.4; silver, 0.7 vs. 0.3; cobalt, 0.07 vs. 0.04. A summary of literature reported concentration of metals in human nail is also presented.

Adult↗

Effects of dark adaptation on spatial and temporal properties of receptive fields in cat lateral geniculate nucleus.

1. We studied the effect of dark adaptation on the spatial organization of receptive fields of single cells in the lateral geniculate nucleus l.g.n. of the cat. 2. Contrary to previous reports, we found that in many l.g.n. cells the ability of the receptive field surround to suppress the response of the centre was diminished following dark adaptation. 3. The degree of reduction of the surround antagonistic strength varied from cell to cell, and was independent of the various classifications of visual neurones (X/Y, ON/OFF, layer, A/layer, A1 and central/peripheral). 4. Most cells also showed an increase in the apparent size of the excitatory centre upon dark adaptation. On the average, the width of the most effective bar stimulus located at the centre of the receptive field increased more than twofold. 5. We also studied the effect of dark adaptation on the temporal properties of l.g.n. receptive fields. In many cells dark adaptation changed the temporal modulation transfer function: it flattened the amplitude function, and changed the phase relationship between the centre response and the surround response. 6. Retinal ganglion cells showed qualitatively similar behaviour to that of l.g.n. neurones. 7. Our data do not support the notion that retinal ganglion cell centres converge on l.g.n. cells to form their surround mechanism.

Action Potentials↗

Continuous monitoring and control of plasma glucose during operation for removal of insulinomas.

A glucose-controlled insulin and glucose infusion system (Biostator system, Miles Laboratories Inc., Elkhart, Ind.) was used during operation for removal of four suspected insulinomas. In two patients the Biostator system continuously monitored plasma glucose levels and, through a computer-controlled feedback mechanism, automatically infused insulin or glucose as needed. In this way plasma glucose could be kept at approximately 110 mg/dl throughout the procedure. In one patient a rise in insulin infusion rate and a fall in glucose infusion rate followed removal of the tumor. In the other, absence of these findings was consistent with the clinical suspicion that the source of hypoglycemia had not been removed. In two other patients the Biostator system continuously monitored the patient's plasma glucose, without feedback-controlled administration of insulin or glucose. This demonstrated that, in these patients, tumor manipulation and removal did not lead to severe hypoglycemia, and thus eliminated any need to prophylactically infuse large amounts of glucose. Successful tumor removal was followed by a rise in blood glucose levels in both of these individuals. The glucose-controlled insulin and glucose infusion system appears to be a useful instrument for intraoperative management of patients with suspected insulinomas.

Adenoma, Islet Cell↗

Gonadal dysgenesis in a phenotypic female with an XY chromosomal constitution.

A phenotypic female with an XY karyotype and pure gonadal dysgenesis is described. Bilateral streak gonads may be found in patients with features of Turner's syndrome and also in phenotypic females without the somatic abnormalities described in Turner's syndrome. Mixed gonadal dysgenesis refers to the presence of a unilateral streak gonad and contralateral testis in a phenotypic female. Dysgenetic gonads are more liable to undergo malignant change, especially in patients with an XY karyotype, and in those with mixed gonadal dysgenesis. Laparotomy and removal of the dysgenetic gonads is indicated in patients with an XY karyotype. If a 46,XX chromosomal pattern is present, the malignant potential is probably less, but laparotomy is still indicated to enable a prognosis to be given regarding fertility.

Adult↗

A generalized epileptiform convulsion after intra-amniotic prostaglandin with intravenous oxytocin infusion: a case report.

A patient who had a generalized epileptiform convulsion after intra-amniotic prostaglandin F2 alpha administration with intravenous oxytocin infusion is described. The convulsion was possibly due to either or both of these drugs. The aetiological associations are reviewed. Intra-amniotic prostaglandins and intravenous oxytocin are frequently used to induce mid-trimester abortions, and the case described serves as a reminder of some of the dangers associated with this procedure.

Abortion, Therapeutic↗

The changing survivorship of white and black children with leukemia.

A study was conducted in metropolitan Baltimore to examine changes in survival of white and black children with acute leukemia from 1960 through 1975. Two-hundred eighty-seven cases were identified, of which 77% were acute lymphocytic leukemia (ALL). Eighty-three percent of all cases occurred in white children. In white children with ALL, two-year survival rates increased from 32% in 1960--64 to 47% in 1965--69, and to 79% in 1970--75 (p less than .005). In the small sample of black children with ALL, two-year survival rates increased from 25% in 1960--64 to 59% in 1965--69 (p less than .01), with no further increase in 1970--75. For acute nonlymphocytic leukemia (ANLL), survivorship was analyzed in white children, among whom one-year survival rates increased from 42% in 1965--69 to 71% in 1970--75 (p less than .005). The increasingly better survival over time of white children with acute leukemia probably reflects the increasing efficacy of new therapeutic approaches.

Acute Disease↗

The eel retina. Receptor classes and spectral mechanisms.

Light and electron microscopy revealed that there are both rods and cones in the retina of the eel Anguilla rostrata. The rods predominate with a rod to cone ratio of 150:1. The spectral sensitivity of the dark-adapted eyecup ERG had a peak at about 520 nm and was well fit by a vitamin A2 nomogram pigment with a lambdamax = 520 nm. This agrees with the eel photopigment measurements of other investigators. This result implies that a single spectral mechanism--the rods--provides the input for the dark-adapted ERG. The spectral sensitivity of the ERG to flicker in the light-adapted eyecup preparation was shifted to longer wavelengths; it peaked at around 550 nm. However, there was evidence that this technique might not have completely eliminated rod intrusion. Rod responses were abolished in a bleached isolated retina preparation, in which it was shown that there were two classes of cone-like mechanisms, one with lambdamax of 550 nm and the other with lambdamax of less than 450 nm. Ganglion cell recording provided preliminary evidence for opponent-color processing. Horizontal cells were only of the L type with both rod and cone inputs.

Animals↗