Biomedical subjects
R Kaplan
Publications and source records attributed to R Kaplan.
The battle of the couches and the rats.
Explore the source record for details and available documents.
Factitious patients with fictitious disorders: a note on Munchausen's syndrome.
Explore the source record for details and available documents.
Reduced glomerular thromboxane receptor sites and vasoconstrictor responses in diabetic rats.
Glomerular thromboxane production and urinary thromboxane excretion are increased in early diabetes, but in spite of this renal blood flow and glomerular filtration rate are significantly higher than in control animals. To study the possibility of a defect in thromboxane actions in the kidney, we have measured glomerular thromboxane receptors and the renal hemodynamic response to the administration of a stable thromboxane analog in diabetic rats. Glomerular thromboxane receptors were studied in hyperglycemic diabetic rats 7 to 10 days after injection of streptozotocin (65 mg/kg, i.v.) and in normal controls. Scatchard analysis of equilibrium binding using the thromboxane antagonist, [3H]-SQ29548, demonstrated one class of high affinity thromboxane receptor sites in control (Kd = 19.9 +/- 2.6 nM, N = 16) and diabetic rats (Kd = 19.8 +/- 2.1 nM, N = 8, P = NS). The number of thromboxane receptors was reduced by 44% in diabetic rats (control, 374 +/- 20 vs. diabetic, 210 +/- 21 fmol/mg, P less than 0.01). Thromboxane binding in diabetic rats was not restored to normal levels by thromboxane synthetase inhibition with OKY046. Diabetic rats had higher renal blood flow (diabetic, 7.03 +/- 0.18 vs. control, 6.33 +/- 0.13 ml/min, P less than 0.05) and glomerular filtration rate (2.42 +/- 0.10 vs. 1.96 +/- 0.07 ml/min, P less than 0.05). Infusion of the stable thromboxane agonist, U46619 (0.1 micrograms/kg/min), reduced renal blood flow and glomerular filtration rate in all animals, but the constrictor responses were blunted by 50% in hyperglycemic diabetic rats compared with normal controls or euglycemic diabetic rats (P less than 0.05). Control of blood glucose with insulin normalized the number of glomerular thromboxane receptor sites, reversed hyperfiltration and restored glomerular responses to thromboxane agonist. The abnormalities of glomerular thromboxane receptors are similar to changes in angiotensin II receptors, and suggest a generalized defect in vasoconstrictor receptors in the diabetic kidney.
Isolated masseter muscle spasm versus generalized rigidity?
Explore the source record for details and available documents.
Psychiatrist-patient relationships.
Explore the source record for details and available documents.
Obstructive sleep apnoea and depression--diagnostic and treatment implications.
Sleep apnoea (OSA), a common sleep disorder, is well recognised as a cause of morbidity including psychiatric disorders. There is increasing recognition of the link between OSA and depression. Sleep changes are intrinsic to depressive disorders, most notably disturbances of REM sleep; OSA causes predominantly REM sleep disturbances. The neuro-vegetative features of depression are similar or identical to the symptoms of OSA-an issue which has not achieved wide clinical recognition. A growing number of studies confirm the statistical link between the two conditions. The implications are twofold: OSA needs to be excluded in cases of chronic or resistant depression and treatment of OSA will make it easier to treat the primary depressive disorder. A new method of treatment for OSA, the Sullivan continuous positive airway pump (CPAP), raises the theoretical possibility of treating depression by this means as well.
Glycosylated serum ferritin in patients with hematological malignancies before and after bone marrow transplantation.
Glycosylated and total serum ferritin levels were monitored in patients with acute leukemia and lymphoma undergoing bone marrow transplantation (BMT). Serum ferritin was high in relapsing patients and normal in most patients in complete remission (CR). In patients with an uncomplicated course, levels of ferritin increased during the first month after BMT with subsequent decrease. Three patients with lymphoma and five with acute leukemia had high serum ferritin levels despite achieving apparent complete hematological remission which was of short duration. The results were compared with groups of lymphoma patients at presentation and during remission and with healthy normal controls. In all the lymphoma patients and in 3 of the 5 leukemia patients the percent of ferritin glycosylation was normal at CR. It was low at the time of diagnosis in all patients. Thus, the percent glycosylation proved a more reliable marker for clinical remission than total serum ferritin. During follow up after BMT in uncomplicated cases, the percent of glycosylated ferritin returned to normal levels earlier than the total serum ferritin. These findings indicate that the evaluation of the amount of glycosylated ferritin may provide useful information in hematological patients in whom there is a discrepancy between high serum ferritin levels and the clinical condition.
The Yankton Model Program.
Changes in medical education towards a student-centered, problem-based learning, with continuity care experience in ambulatory settings have been recommended. The University of South Dakota School of Medicine has developed such an educational model for third year medical students named the Yankton Model Program and is herein described.
Medical causes of male sexual dysfunction.
Explore the source record for details and available documents.
Bullous pyoderma gangrenosum after granulocyte colony-stimulating factor treatment.
The hematopoietic growth factors are under investigation for the treatment of patients with chemotherapy-induced bone marrow suppression. One such trial at the University of California, Los Angeles involves chemotherapy with or without granulocyte colony-stimulating factor (G-CSF) in patients with small cell lung cancer. The authors report a case of a patient who had bullous pyoderma gangrenosum at the site of previous eczema during treatment with G-CSF. The lesions resolved promptly when the drug was discontinued. Other investigators have recently reported inflammatory complications of G-CSF and granulocyte-macrophage colony-stimulating factor (GM-CSF) but this is the first case report of biopsy-proven neutrophilic dermatosis associated with administration of a hematopoietic growth factor. Patients should be monitored for development of inflammatory processes during G-CSF therapy and this therapy should be given with caution to those patients with existing inflammatory conditions.
EcoRI and PvuII RFLPs in the endonexin II/annexin V (ANX5) gene on chromosome four.
Explore the source record for details and available documents.
Bilateral burning foot pain: monitoring of pain, sensation, and autonomic function during successful treatment with sympathetic blockade.
We describe a patient with burning pain in both feet associated with local autonomic disturbances following bilateral traumatic sciatic mononeuropathies. The diagnosis of a sympathetically maintained pain was confirmed through a prompt response to sympathetic blockade. Although a mild alcohol-nutritional neuropathy was found, the clinical findings strongly suggested a diagnosis of bilateral causalgia. Clinical evaluation and quantitative sensory testing were performed prior to and after successive unilateral lumbar sympathetic nerve blocks. After unilateral blockade, bilateral improvement was recorded in measures of pain, sudomotor function, and foot temperature. Other measures of autonomic function showed variable responses to sympathetic blockade. Quantitative sensory testing revealed a dramatic alteration in the contralateral limb's thermal sense following unilateral block. This case underscores the potential for bilateral causalgia and provides additional evidence for a central mechanism operating in this disorder. The relationship between bilateral causalgia and the "burning feet syndrome" in alcoholic neuropathy is discussed.
Neuroleptic effects on regional brain metabolism in first episode schizophrenics.
Explore the source record for details and available documents.
Molecular cloning and expression of biologically active human glia maturation factor-beta.
Glia maturation factor-beta, a protein found in the brains of all vertebrates thus far examined, appears to play a role in the differentiation, maintenance, and regeneration of the nervous system. Using oligonucleotide probes based on the sequences of three tryptic peptides derived from bovine glia maturation factor-beta, we screened a human brainstem cDNA library in lambda gt11. A 0.7-kb clone was isolated, sequenced in its entirety, and found to encode a polypeptide of 142 amino acids which contained regions identical to the three bovine peptides. This polypeptide, human recombinant glia maturation factor-beta, has been expressed in Escherichia coli and found to possess structural characteristics and biological activity indistinguishable from those of the native bovine protein.
Posterior cortical dementia with alexia: neurobehavioural, MRI, and PET findings.
A progressive disorder of relatively focal but asymmetric biposterior dysfunction is described in a 54 year old right handed male. Initial clinical features included letter-by-letter alexia, visual anomia, acalculia, mild agraphia, constructional apraxia, and visuospatial compromise. Serial testing demonstrated relentless deterioration with additional development of transcortical sensory aphasia, Gerstmann's tetrad, and severe visuoperceptual impairment. Amnesia was not an early clinical feature. Judgment, personality, insight, and awareness remained preserved throughout most of the clinical course. Extinction in the right visual field to bilateral stimulation was the sole neurological abnormality. Early CT was normal and late MRI showed asymmetrical bioccipitoparietal atrophy with greater involvement of the left hemisphere. Results from positron emission tomography (PET) showed bilaterally asymmetric (left greater than right) occipitotemporoparietal hypometabolism. The metabolic decrement was strikingly asymmetric with a 50% reduction in glucose consumption confined to the left occipital cortex. The picture of occipitotemporoparietal compromise verified by MRI, PET, and neurobehavioural testing would be unusual for such degenerative dementias as Alzheimer's (AD) and Pick's disease, although atypical AD with predominant occipital lobe involvement cannot be excluded. This case supports the concepts of posterior cortical dementia (PCD) as a clinically distinct entity and for the first time documents its corresponding metabolic deficit using PET.
The benefits of nearby nature for elderly apartment residents.
Few studies have examined the potential value of nearby nature for elderly adults. In the current study, elderly residents of two apartment complexes were interviewed about the availability of and the importance of different nearby natural settings. They were also asked how involved they were with various "nature compensations"--indoor activities, such as growing houseplants or watching nature programs on television, which might substitute for more strenuous outdoor activities. The results indicate that elderly adults consider access to nature near their homes to be very important. Nature compensations were frequently pursued but did not affect satisfactions. Satisfaction levels were significantly higher among residents whose apartments overlooked natural settings, and among those who lived closer to certain kinds of outdoor settings.