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Biomedical subjects

A S Baker

Publications and source records attributed to A S Baker.

At least 91 records · Page 5Linked to original sources

Chronic peritoneal dialysis in a patient with primary amyloidosis, renal failure, and factor X deficiency.

Chronic peritoneal dialysis was used in a patient with renal failure due to primary amyloidosis. Paraprotein was demonstrated in serum and urine, and was removed in peritoneal dialysate. The patient objectively improved as long as he was receiving peritoneal dialysis. When dietary indiscretion necessitated hemodialysis for fluid removal, he died shortly thereafter of subdural hematomas, possibly aggravated by factor X deficiency. Reasons for selecting chronic peritoneal dialysis as the treatment of choice in patients with renal failure associated with overproduction of paraprotein are discussed.

Amyloidosis↗

What do family physicians in a prepaid group do in their offices?

Each family physician at the Permanente Group of San Diego was observed for one half-day. As with two earlier time studies, the time spent with each patient was tabulated to show the number of minutes used in each of the usual activity categories that are encompassed in a patient encounter. Previously, similar studies had been carried out with rural practitioners in Missouri (1965) and rural and urban physicians in New Zealand (1975). The Missouri physicians practicing in pre-Medicaid days spent less time doing administrative work than their counterparts in this study, but appreciably more time in treatment and preventive activities. The time utilization of the physicians in prepaid groups was remarkably similar to that of the physicians in the fee-for-service system in New Zealand.

California↗

Adenylate cyclase and phosphodiesterase activity in the platelet release abnormality.

11 patients with histories of clinical bleeding were selected as examples of platelet release abnormality. Mean bleeding time was 18 +/- 2.6 min (normal +/- SEM; 6 +/- 0.44); mean platelet adhesiveness was 9.9 +/- 4.3% (normal +/- SEM; 30 +/- 2.2). Clot retraction and platelet factor 3 were normal. Platelet aggregation with adenosine diphosphate (ADP), epinephrine and collagen was decreased, as was 14C-serotonin release. Electron microscopic studies of platelets exposed to epinephrine showed 2 subgroups: one which failed to aggregate or have centralization of organelles and a second which developed pseudopodia and centralization of organelles, but rarely aggregated or degranulated. Measurements of activity of adenylate cyclase and phosphodiesterase under basal conditions were performed on platelets from patients and control subjects. Adenylate cyclase activity was significantly lower and phosphodiesterase activity significantly higher in the patient group. Prostaglandin E1 was a potent stimulator of adenylate cyclase in both groups, as was NaF. It was concluded that the causative defects with "platelt release abnormality" do not reside in either the activity of adenylate cyclase or of phosphodiesterase. Changes in formation and destruction of cyclic adenosinemonophosphate (AMP) may instead be regarded as a compensatory response to a defect in another effector system.

Adenylyl Cyclases↗

Gamma heavy chain disease--presenting as pancytopenia and splenomegaly.

A patient with gamma heavy chain disease (Franklin's disease) was discovered during evaluation for pancytopenia and splenomegaly. Lymphadenopathy, palatal edema, and infiltration of the bone marrow palatal edema, and infiltration of the bone marrow with abnormal cells were all absent. Serum and urine protein electrophoresis demonstrated a monoclonal protein migrating in the beta region. Immunoelectrophoresis showed that it reacted with antibodies against the Fc fragment of IgG heavy chains (gamma chains) but not with antibodies against kappa and lambda but not with antibodies against kappa and lambda light chains of Fab fragments. In the first year after detection of the disease, the patient had acute cholecystitis and disseminated herpes zoster. Sixteen months after diagnosis he died of overwhelming pneumonia caused by Pseudomonas aeruginosa and lebsiella neumoniae. A striking feature of his illness was his asymptomatic presentation, with pancytophenia and splenomegaly the only indication of this disease.

Cholecystitis↗

Detection of cytotoxic antibody to erythroblasts.

A two-stage test of cytotoxicity for erythroblasts has been developed that is faster and more sensitive than a previous method. Release of 59Fe from erythroid precursors was used as an index of cytotoxic injury. Optimal release was obtained by pretreating the labeled marrow cells with 0.46M reduced glutathione (GSH) at pH 8.0 for 1 hour at 37 degrees C. The first-stage test plasmas or IgG globulins were incubated with the treated cells at 22 degrees C. for 1 hour and the second-stage source of complement was incubated with the cells for 1 hour at 37 degrees C. These changes permitted cytotoxic plasmas to be detected when they previously would not have been identified. Substitution of the GSH by trypsin or neuraminidase did not yield comparable results. Measurement of the cytotoxicity for GSH-treated cells by the trypan blue exclusion technique showed that the loss of exclusion of trypan blue by marrow erythroblasts increased with an increased release of 50Fe. No cytotoxicity was detected if complement was inactivated at 56 degrees C. The results observed with trypan blue and the occurence of cytotoxicity with the addition of IgG globulins and complement indicate that this system can be used to detect cytotoxic antibody to erythroblasts.

Animals↗

What do New Zealand general practitioners do in their offices?

A third person physician observer timed 16 New Zealand general practitioners during a work day during summer months. Usual office hours for the 16 physicians occupied over seven hours, during which time the patient list averaged 26 persons. Greatest time span, 27 percent, used in diagnosis, but substantial time was spent in health education, counseling and administration. The distribution of patients' problems was greatest in respiratory disease, followed by musculoskeletal, dermatologic and urogenital. There is considerable similarity to practice patterns of rural physicians in Missouri, USA.

Adolescent↗

Spinal epidural abscess.

Thirty-nine patients with spinal epidural abscess were evaluated at the Massachusetts General Hospital between 1947 and 1974. Twenty had acute symptoms, and purulent epidural collections were present; 19 had prolonged courses, and epidural granulation tissue was observed at operation. Staphylococcus aureus was the most common etiologic agent (57 per cent), followed by streptococci (18 per cent) and gram-negative bacilli (13 per cent). The source of infection was osteomyelitis in 38 per cent of cases and bacteremia in 26 per cent. In 16 per cent epidural abscess was due to postoperative infection. The progression from spinal ache to root pain to weakness followed by paralysis continues to be characteristic of spinal epidural abscess. Although the disease is uncommon, the complications are so serious that prompt diagnosis and treatment are of paramount importance. The combination of back pain with fewer and local tenderness is an indication for cerebrospinal-fluid examination and, depending on the results, immediate performance of myelography.

Abscess↗