Clinicopathological characteristics of dialysis patients with spinal cord injury

Forty-three spinal cord injured patients with endstage renal disease (ESRD) maintained on hemodialysis were studied. The most prevalent renal lesions consisted of chronic pyelonephritis and amyloidosis while the main renal functional features included nephrotic range proteinuria, high urine output and relatively low serum creatinine for the degree of renal insufficiency. Normocytic, normochromic anemia with low reticulocyte response, low serum iron and iron binding capacity and high transfusion requirement and serum ferritin were noted. Various cardiovascular, pulmonary and gastrointestinal abnormalities were found with considerable frequencies. The incidence of amyloidosis was much higher than that reported previously. This is thought to be due to continued progression of amyloidosis occasioned by longer survival in the present series.

Bacterial infections in patients with chronic renal failure: occurrence with spinal cord injury

The available data were examined from 43 patients with spinal cord injuries and end-stage renal disease undergoing dialysis. All but one patient had a chronic urinary tract infection, which was characterized by persistence of the same organisms for prolonged periods, high prevalence of mixed infections, scarcity of symptoms, lack of fever of leukocytosis, and a considerable prevalence of cross-infection with the decubitus ulcers. Staphylococcus aureus and various Gram-negative organisms were responsible for most of the vascular access infections in our patients. Decubitus ulcers were common and were frequently infected. Cross-contamination between infected decubitus ulcers, the urinary tract, and vascular access seemed to have occurred on several occasions. The recorded respiratory infections were preponderantly caused by Gram-negative organisms. Urinary tract, vascular access, and decubitus infections seemed to be the source of septicemia in most of the recorded instances. Septicemia was the immediate cause of death in half of the patients.

Hematologic features of chronic renal failure associated with spinal cord injury

We examined the available hematologic data on 43 spinal cord injury (SCI) patients with end-stage renal disease (ESRD) treated with hemodialysis since 1972. A control group consisting of 45 ESRD patients without SCI was included for comparison. Moderate to severe anemia was found in all patients. The observed anemia was generally normocytic, normochromic, and associated with a low reticulocyte response. Transfusion requirement in the SCI group was considerably more than in the control group. There was a high incidence of splenomegaly, splenic amyloidosis, and lymph node enlargement in the SCI group. Lymph node and bone marrow amyloid deposits were found in some SCI patients but not in the control subjects.

The effects of chronic oral cimetidine therapy on the cardiovascular system in man

1 The demonstration of histamine (H2) receptors in the cardiovascular system in man and the widespread use of the specific H2 receptor antagonist cimetidine for the treatment of peptic ulcer has necessitated assessment of the cardiovascular effects of this drug during oral therapy in man. 2 Consequently, nineteen patients with a history of peptic ulcer but in symptomatic remission underwent a double-blind crossover trial of oral cimetidine v placebo, each treatment period lasting 4 weeks. No significant difference in various cardiac parameters at rest (heart rate, blood pressure, ECG) or following a maximal treadmill exercise test (time-into-protocol, maximum heart rate and blood pressure) was found between the groups. Similarly, cimetidine produced no change in the incidence of ventricular ectopics or in heart rate on 24 h ambulatory monitoring and had no effect on left ventricular volume or contractility as measured by echocardiography. 3 Thus oral administration of cimetidine in a dose of 400 mg four times daily was associated with no demonstrable cardiovascular changes. In addition, since this dose is thought compatible with cardiovascular H2 receptor blockade this study favours the lack of a physiological role for these receptors in man.

Ineffectiveness of intravenous ascorbic acid as an acidifying agent in man

The acidifying effect of intravenous (IV) ascorbic acid was studied in seven healthy adult volunteers. After obtaining baseline urine and blood samples, 2-g IV doses of ascorbic acid were administered to each subject during a 20-minute period. Venous blood samples were obtained at times 0.5, 1, and 2 hours, and urine was collected at times 0.5, 1, 2, and 3 hours. Our results show that venous blood pH, plasma bicarbonate concentration, urine PCO2, and urine bicarbonate excretion did not change significantly during the study period. Urinary titratable acidity, ammonium excretion, and net hydrogen ion excretion decreased, and urinary pH actually showed a significant rise at two hours. We therefore conclude that IV ascorbic acid administered in recommended doses does not effectively acidify urine.

Preservation of urinary postprandial alkaline tide despite inhibition of gastric acid secretion

Ingestion of food leads to a rise in urinary pH. This phenomenon is commonly known as "postprandial alkaline tide" and is generally attributed to acid secretion in the stomach. To examine this hypothesis, we studied the changes of urinary pH, H+ concentration, PCO2, and bicarbonate in nine healthy volunteers with and without histamine H2 receptor blockade, using cimetidine and placebo medication. Postprandial alkaline tide persisted and was even exaggerated during treatment with cimetidine. Preservation of postprandial urinary alkaline tide, despite the expected inhibition of gastric acid secretion by cimetidine, tends to exclude a causal relation between alkaline tide and gastric acid secretion.

Assessment of prognostic factors in patients undergoing surgery for non-rheumatic mitral regurgitation

Twenty-four patients who had undegone mitral valve surgery for pure non-rheumatic mitral regurgitation were studied non-invasively six months to six years postoperatively. The long-term results of operation were assessed on the basis of clinical history, echocardiography, and treadmill stress testing using a points scoring system. The score so obtained was used to divide the patients into those with a good response to surgery (group 1) and those responding poorly (group 2). The effects on the long-term surgical outcome of several intraoperative and preoperative factors were then analysed both together and separately. A short symptomatic history (less than 1 year), a normal left ventricular end-diastolic volume index (less than or equal to 100 ml per m2), and a large post-ectopic potentiation of KV max (greater than 50 s-1) were found to be favourable prognostic factors when analysed independently. An angiographic ejection fraction less than 0.5 was uniformly associated with a poor outcome, and 71 per cent of patients in atrial fibrillation at the time of operation also responded badly. In those patients with good long-term function, cold potassium cardioplegia was more commonly used than intermittent aortic cross clamping as the means of intraoperative myocardial preservation, though this difference did not reach conventional significance. A standard analysis of variance allowed assessment of length of history, left ventricular end-diastolic volume index, and type of valve prosthesis simultaneously. This indicated that both length of history and left ventricular end-diastolic volume index were highly significant prognostic factors. The use of a Björk-Shiley as opposed to a Starr-Edwards prosthesis also emerged as significantly favouring a good long-term result. The state of the left ventricular myocardium before operation and the type of valve prosthesis used were thus shown to be the prime determinants of surgical outcome in these patients. The optimum time for operation was shown to be within one year of the onset of symptoms, and before the left left ventricular end-diastolic volume index exceeds 100 ml per m2, or the ejection fraction falls to less than 0.5. At such a time, irreversible changes in myocardial function sufficient to negate the beneficial effects of mitral valve surgery have not yet occurred.

Surveyor I: location and indentification

Surveyor I landed on the lunar surface on 2 June 1966 and obtained more than 11,000 pictures of the environment with its television camera. The same region was photographed by the 24-inch (61-centimeter) camera of Orbiter III on 22 February 1967. Surveyor I has been located in these Orbiter photographs; its image was found and all search and identification criteria were satisfied by the site.