PubMed HealthSearch

Biomedical subjects

J T Harrington

Publications and source records attributed to J T Harrington.

At least 19 recordsLinked to original sources

Musculoskeletal pain and work disability.

Musculo-skeletal pain caused by neck and back injury, cumulative trauma to the upper extremities, fibromyalgia, and reflex dystrophy is an important cause of worker disability. Physicians are involved not only in the care of injured workers, but in providing independent medical opinions regarding such injuries. Advances in medical knowledge permit better understanding and management of these injuries, and it is the responsibility of all physicians to provide accurate diagnosis, treatment, and information to patients, employers, insurers, and the workers compensation system.

Back Pain

Prolonged survival with a remnant kidney.

Surgical ablation of five-sixths renal mass in Munich-Wistar rats fed a high protein diet leads to focal sclerosis in the remnant kidney and progressive renal failure. Experimental data suggest that this injury results from intraglomerular hypertension and/or chronic glomerular hyperfiltration. Data in humans largely are limited to patients with unilateral renal agenesis or uninephrectomy, either for unilateral renal disease or for kidney transplant donation. Isolated case reports have documented focal sclerosis and progressive renal failure in two patients with a remnant kidney. To obtain data in humans with a remnant kidney, we surveyed more than 800 urologists and nephrologists in the United States and abroad. Criteria for inclusion in the study were (1) surgical resection (in one or more operations) resulting in the presence of a remnant kidney; and (2) an adequate period of follow-up, defined as 5 years or greater. A total of 13 patients were identified (from 13 different centers). Twelve patients had renal cancer and one had tuberculosis. Six patients were observed for 10 or more years postoperatively and all have stable serum creatinine levels of less than 270 mumol/L (3.0 mg/dL); two of these six patients are now more than 25 and 30 years postoperation. The other seven patients, observed for 5 to 7 years, have serum creatinine levels less than 270 mumol/L (3 mg/dL), while one has an increasing serum creatinine level. The two longest surviving patients both have undergone successful pregnancy with no overall change in serum creatinine. These observations demonstrate that it is possible for humans to survive more than 30 years with a stable serum creatinine, despite the presence of only a remnant kidney.

Adult

The effect of potassium ion depletion on postinfarction canine cardiac arrhythmias.

The effect of potassium ion (K+) depletion on postmyocardial infarction ventricular arrhythmias was investigated in 32 dogs: 12 control animals, 10 animals that ate a diet extremely low in K+ for 15 days, and 10 others that, in addition to dietary K+ deprivation, received 50 mg of hydrochlorothiazide four times. The experimental myocardial infarction was created by proximal left anterior descending coronary artery ligation. In a subgroup of 24 animals selected for relatively uniform size of myocardial infarction (14% to 22% of left ventricular mass), eight animals with mean cumulative K+ balance of -4.01 +/- 2.19 meq/kg developed spontaneous ventricular fibrillation within 4 to 17 min of coronary ligation, whereas 16 animals with a mean cumulative K+ balance of -0.11 +/- 1.82 meq/kg didn't. By univariate analysis cumulative K+ deficit (p = .001) and plasma K+ concentration (p = .039) correlated significantly with spontaneous ventricular fibrillation. Multivariate analysis of the entire population of 32 animals identified cumulative K+ deficit and size of myocardial infarction as the only independent predictors of ventricular fibrillation. Cumulative K+ deficit was also an independent predictor of ventricular fibrillation induced by programmed cardiac stimulation in the conscious state 1 day after myocardial infarction.

Animals

Mineralocorticoid-stimulated renal acidification: the critical role of dietary sodium.

Recent in vitro studies of isolated distal nephron segments have demonstrated that mineralocorticoid hormone stimulates H+ secretion by both Na+-dependent and Na+-independent mechanisms, and the Na+-independent acidification mechanism has a greater capacity. These in vitro data suggest that mineralocorticoid administration in vivo might increase renal acid excretion when an augmentation in distal Na+ reabsorption is precluded by rigid restriction of dietary Na+; under these circumstances, virtually all Na+ delivered to the distal nephron is reabsorbed in the basal state. In the present studies, prolonged (12 days) administration of DOC (15 mg/day) was undertaken in both Na+-fed and rigidly Na+-restricted dogs with chronic HCl acidosis. Na+-fed animals responded to DOC administration with a large increment in net acid excretion and complete correction of metabolic acidosis. Marked hypokalemia and significant kaliuresis also occurred. Na+-restricted dogs experienced no changes in renal acid excretion, systemic acid-base equilibrium, plasma [K+] or K+ balance. These results suggest that both renal H+ and K+ excretory responses to prolonged mineralocorticoid hormone administration in vivo are critically dependent on the availability for reabsorption of surplus Na+ within the distal nephron; this requirement is met when the diet, and hence the final urine, contains Na+ but cannot be satisfied when dietary Na+ is rigidly restricted.

Acidosis

The characteristics of training in ambulatory medicine in U.S. residencies.

To determine the characteristics of training in ambulatory internal medicine, all internal medicine residency programs in the United States were surveyed in 1981-82. Thirty-eight percent of 477 hospitals responded. Quantitative information was sought regarding the specific features of the ambulatory residency programs, formal teaching conferences, supervision of residents, and evaluation of residents in ambulatory care. According to the responses, the training of the small cadre of primary care residents does emphasize ambulatory medical experience, supervised by an increasing number of faculty members in general medicine. Formal post-clinic conferences, analogous to inpatient attending rounds, are held substantially more often in hospitals with primary care programs than in hospitals without primary care programs. Formal ambulatory teaching conferences stress both traditional topics important in internal medicine and psychosocial issues. However, the authors could detect little effect of these activities in primary care programs on the training of traditional internal medicine residents even within the same hospital.

Ambulatory Care

Drug-induced hyperkalemia.

After reviewing the available data on drug-induced hyperkalemia, we conclude that the situation has not improved since Lawson quantitatively documented the substantial risks of potassium chloride over a decade ago (90). As discussed, the risk of developing hyperkalemia in hospital remains at least at the range of 1 to 2% and can reach 10%, depending on the definition used (Table 2). Potassium chloride supplements and potassium-sparing diuretics remain the major culprits but they have been joined by a host of new actors, e.g., salt substitutes, beta-blockers, converting enzyme inhibitors, nonsteroidal antiinflammatory agents, and heparin, among others. Readily identifiable risk factors (other than drugs) for developing hyperkalemia are well-known but seem to be consistently ignored, even in teaching hospitals. The presence of diabetes mellitus, renal insufficiency, hypoaldosteronism, and age greater than 60 years results in a substantial increase in the risk of hyperkalemia from the use of any of the drugs we have reviewed. If prevention of hyperkalemia is the goal, as it should be, the current widespread and indiscriminate use of potassium supplements and potassium-sparing diuretics will need to end. We remain intrigued by Burchell's prescient pronouncement of over a decade ago that "more lives have been lost than saved by potassium therapy" (28).

Adrenergic Agonists

Leukocyte migration inhibition in vitro in bladder carcinoma.

The leukocyte migration inhibition response in vitro of peripheral blood leukocytes from patients with transitional cell carcinoma of the urinary bladder, other genitourinary diseases, and normal controls was studied. The agarose droplet migration inhibition method was used to determine the cell-mediated immune reactivity of bladder tumor patients to antigens derived from allogeneic bladder tumor cell lines by hypertonic potassium chloride extraction. Sixty-nine bladder tumor patients were tested 131 times and included 68 positive and 63 negative results. A positive assay was shown to correlate strongly with the presence of tumor at the time of testing (p less than 0.001). Five of 24 patients with other genitourinary diseases had positive inhibition assays, but none of the 26 normal controls were positive. These results suggest that this in vitro assay method may prove valuable in monitoring bladder tumor patients for completeness of initial tumor resection and for clinical recurrence as well as for further studies of the tumor-specific immune response in this disease.

Antigens, Neoplasm

Serum electrolyte and acid base composition. The influence of graded degrees of chronic renal failure.

Data from 41 ambulatory patients with graded degrees of uncomplicated, chronic renal failure were used to define the quantitative relationship between serum acid-base and electrolyte composition and the serum creatinine level. Even in patients with only moderate renal insufficiency, serum total carbon dioxide (tCO2) content was reduced significantly. This early fall in tCO2 was offset by an increase in serum chloride (Cl-), serum undetermined anton concentration (A-) remaining normal. In patients with more severe degrees of renal insufficiency, further decrements in tCO2 occurred that were proportional to the increment in serum creatinine. These latter decrements in tCO2 were associated with equivalent increments in A-, serum Cl- remaining unchanged at the elevated level observed during moderate renal insufficiency. Confidence limits of 95% for tCO2 and A- were calculated from the data.

Acid-Base Equilibrium

Transcatheter thromboembolectomy of acute renal artery occlusion.

Direct surgery of the renal artery has been performed for the relief of acute thrombotic or embolic occlusion of the renal artery to restore adequate renal perfusion and prevent irreversible renal failure. Occasionally, severe medical disease may increase surgical risk to a prohibitive level. An angiographic technique has been devised to provide an alternative approach and has been successfully used on five occluded renal arteries in four patients, with measurable benefit.

Acute Disease

Platinum nephrotoxicity.

Platinum coordination complexes have recently been introduced in cancer chemotherapy with considerable success. However, significant nephrotoxicity has emerged as a factor that limits the therapeutic usefulness of these compounds. In this article we review the available knowledge on platinum nephrotoxicity and its prevention that has been derived from both toxicologic studies in animals and clinical trials in human subjects.

Acute Kidney Injury

In vitro assessment of delayed hypersensitivity in the human. Inhibition of cell migration from agarose microdroplets.

The in vitro migration inhibition responses of peripheral blood leukocytes from tuberculin skin test positive and negative donors were tested to validate and determine optimal conditions for the agarose droplet method in the human. In vitro migration inhibition was observed in skin test positive donors in the presence of 25 microgram PPD/ml of medium using both unfractionated leukocytes and a mixture of immune lymphocytes with allogeneic polymorphonuclear leukocyte indicators. The supernatants of tuberculin positive lymphocytes cultured with PPD also inhibited the migration of human polymorphonuclear leukocytes and guinea pig peritoneal exudate cells but did not alter that of murine peritoneal exudate cells. These studies establish that the agarose droplet method is an efficient approach to the in vitro assessment of cell-mediated immunity in the human and define suitable indicator cell populations for assay of human lymphokines.

Animals

Diffuse ischemic colitis associated with systemic lupus erythematosus--response to subtotal colectomy.

A 26-year-old woman with systemic lupus erythematosus developed massive rectal bleeding that failed to respond to medical treatment. X-rays and proctoscopy indicated that she had universal colitis. She underwent emergency subtotal colectomy because of a rapidly declining clinical course. The small intestine appeared normal. Pathological examination demonstrated a gangrenous large intestine, ischemic ulcerations, and extensive fibrinoid vasculitis that was typical of systemic lupus. The patient has had no further gastrointestinal complaints for 2 years since surgery.

Adult

A solid phase radioimmunoassay for detection of serum autoantibodies in systemic lupus erythematosus.

Solid phase radioimmunoassay (RIA) methods for measuring autoantibodies in systemic lupus erythematosus (SLE) patients' serum were developed to improve the sensitivity and quantitative precision of these determinations. Two mechanical systems were studied: (1) acetone fixed cell monolayers in glass tubes and (2) antigen coated plastic beads. Both systems were sensitive and reproducible, giving serum dilution end-points between two and four orders of magnitude (100-10,000 times) greater than those obtained by fluorescence microscopy. The most sensitive, versatile system involves the coating of plastic beads with nuclear antigen(s), incubation overnight with sera and labelling with 125I conjugated antihuman globulin. Linear binding of this radioactive tag is obtained over a wide range of SLE serum dilutions and the slopes of the serum dilution titration curves are almost identical for all SLE patients' sera we have tested. Therefore, a standard titration curve can be constructed from the results with a positive serum, and end-point dilutions of unknown sera estimated from results obtained with a single serum dilution. Alternatively, binding ratios of unknown sera can be usefully compared at fixed dilutions with standard positive and negative sera. For example, high binding ratios (greater than 3.0) were obtained with 19/20 SLE sera and 0/20 control sera. Antigens used in these systems include crude, whole-cell lysates and lysates from purified nuclei. These RIA methods appear to provide certain advantages over existing autoantibody assay methods because they are relatively simple, sensitive, reproducible and potentially capable of measuring a variety of autoantibody specificities.

Antigens