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Biomedical subjects

R A Rosen

Publications and source records attributed to R A Rosen.

At least 19 recordsLinked to original sources

On the mechanism by which chloride corrects metabolic alkalosis in man.

To determine whether administration of chloride corrects chloride-depletion metabolic alkalosis (CDA) by correction of plasma volume contraction and restoration of glomerular filtration rate or by an independent effect of chloride repletion, CDA was produced in normal men by the administration of furosemide and maintained by restriction of dietary sodium chloride intake. Negative sodium balance (-112 +/- 16 meq) and reduced plasma volume (2.53 versus 2.93 liters, p less than 0.05) developed. The cumulative chloride deficit of 271 +/- 16 meq was then repleted by oral potassium chloride (267 +/- 19 meq) over 36 hours with continued serial measurements of glomerular filtration rate, effective renal plasma flow, plasma volume, body weight, and plasma renin and aldosterone levels. CDA was corrected, even though body weight, plasma volume, glomerular filtration rate, and renal plasma flow all remained reduced and plasma aldosterone was elevated; urinary bicarbonate excretion increased during correction. Administration of an identical potassium chloride load to similarly sodium-depleted but not chloride-depleted normal subjects produced no change in acid-base status. It is concluded that chloride repletion can correct CDA by a renal mechanism without restoring plasma volume or glomerular filtration rate or by altering sodium avidity.

Adult

The use of antibiotics in the initial management of recent dog-bite wounds.

The use of antibiotics in the initial management of dog-bite wounds presented within eight hours of injury was studied. Of 211 wounds occurring in 150 patients seen during the study period, 66 wounds occurring in 33 patients comprised the study sample. All wounds were managed according to a strict protocol that included cleaning, debridement, and pressure irrigation. The wounds studied were randomly assigned to either an antibiotics (penicillinase-resistant penicillin or erythromycin) or placebo group. Two of the 35 antibiotic-treated wounds became infected, and three of the 31 placebo-treated wounds became infected. There was no significant difference in outcome between antibiotic and placebo groups. Hand wounds became infected significantly more often than other wounds. The administration of a penicillinase-resistant antibiotic is not indicated in the initial management of dog-bite wounds presented within eight hours of injury.

Adult

Growth arrest recovery lines in hypoparathyroidism.

Dense lines paralleling vertebral end plates with a "bone-in-bone" appearance were seen on radiographs of five patients with idiopathic hypoparathyroidism. The lines are similar to those seen in cases in which there is recovery from a growth arrest. The cause of the lines is unclear and may be related not only to the metabolic process itself, but also to its complications and treatment. The finding, although nonspecific, should bring the possibility of idiopathic hypoparathyroidism to mind.

Adolescent

The value of radiographic and computed tomography in the staging of lung carcinoma.

A prospective double-blind study was undertaken to compare computed tomography (CT) and conventional radiographic tomography (RT) in the staging of lung carcinoma. Seventy-five patients had CT and RT of the mediastinum and hilum prior to operation. The presence or absence of metastasis to lymph nodes documented at the time of operation was the standard applied to the studies. CT correctly predicted the presence or absence of mediastinal lymphadenopathy in most cases (sensitivity 91%, specificity 94%), while RT was less helpful (sensitivity 61%, specificity 86%). Metastatic mediastinal lymph nodes in those patients with false negative CT and RT studies averaged only 0.8 cm in diameter, probably accounting for the negative radiographic findings. Both CT and RT had poor predictive values in detecting hilar lymphadenopathy (sensitivity 73% and 47%, specificity 87% and 72%, respectively). The predictive value of CT in the evaluation of mediastinal lymphadenopathy equaled that of mediastinoscopy or mediastinotomy. When CT of the mediastinum demonstrates no lymphadenopathy, invasive staging can be deferred for definitive thoracotomy. Since false positive values were seen with both CT and RT scans of the mediastinum (4% and 8%, respectively), invasive staging will still be necessary in those patients with positive studies.

Adult

Intracortical fissuring in osteomyelitis.

Cortical fissuring, a well-recognized radiographic sign of osteomyelitis, represents spread of infection through the haversian system with osteoclastic bone resorption. In the proper clinical setting this finding may be recognized before there is other evidence of bone destruction or periosteal reaction. Three cases are presented that illustrate the sign at a relatively early stage in the progress of the osteomyelitis. While fissuring was previously considered evidence of sickle cell anemia, only one of our patients had sickle hemoglobin.

Adult

Effects of inguinal hernias upon the bladder and ureters.

The presence of inguinal hernia may be associated with extrinsic defects upon the bladder and ureter in the absence of actual herniation of the urinary structures. The findings are characteristic unless associated with irregularity of the bladder wall or elevation of the bladder floor by prostatic enlargement. In some cases, the possibility of intrinsic bladder pathology is raised, requiring retrograde study for clarification. Ureteral displacements may be either ipsilateral or contralateral, depending upon the segment of bowel involved and the side of the hernia. The bladder findings are best demonstrated when the patient is prone or upright.

Hernia, Inguinal