Darier's disease and vitamin A. Concentrations of retinoids in serum and epidermis of untreated patients

Blood samples and skin biopsy specimens from 13 male patients with Darier s disease (DD) and 11 healthy male controls were analyzed for carotene, retinol (vitamin A), dehydroretinol (vitamin A2), and retinol-binding protein (RBP). The serum carotene level was lower in the patients than in the controls, but the vitamin A and RBP levels did not differ from those of the controls regardless of the severity of the disease. The RBP could be visualized by immunofluorescence microscopy in the epidermis of both unaffected and lesional skin of patients with DD. In the epidermis of patients with DD (uninvolved and lesional), the carotene content was similar to that of the controls. The retinol content was probably higher than in the controls. By contrast, the dehydroretinol concentration was normal in the uninvolved skin but markedly higher than normal in the lesions, especially in the severe cases. The abnormal distribution of retinoids in DD may reflect localized disturbances of epidermal vitamin A metabolism rather than a defect in serum vitamin A transport.

Renal prostaglandin E2 biosynthesis: dependence on angiotensin II

To study the interaction of the prohypertensive renin-angiotensin axis with the antihypertensive renal prostaglandins, angiotensin-converting enzyme inhibition (captopril and teprotide) and angiotensin blockade (Sar1-Ile8-AII) were produced in rabbits in vivo and renal slice prostaglandin E2 was measured in vitro after 30 minutes of incubation in Krebs-Ringer HCO3- buffer. In rabbits with angiotensin-converting enzyme inhibition, de novo prostaglandin E2 synthesis decreased in cortical, outer medullary and papillary slices by 85, 52 and 47 percent, respectively. Similar degrees of inhibition were observed with angiotensin blockade. It is concluded that renal prostaglandin E2 synthesis is angiotensin II dependent under these conditions. This finding suggests that any increase in the prohypertensive antinatriuretic renin-angiotensin axis may be associated with a secondary increase in renal prostaglandin E2 which may be acting in an antihypertensive natriuretic compensatory fashion.

Inhibition of rabbit renal prostaglandin E2 biosynthesis by chronic potassium deficiency

To test the hypothesis that renal PGs may mediate the renal functional defect of potassium depletion, rabbits were placed on normal potassium and potassium-deficient diets for 7 weeks, and measurements were made of urinary PGE2 excretion; renal cortical, medullary, and papillary PGE2 content; and in vitro, de novo PGE2 biosynthesis. In the sixth week maximal urinary osmolality declined significantly, from 1118 +/- 44 mOsm/kg of H2O in controls to 666 +/- 25 in potassium-deficient animals, accompanied by a corresponding decrease in urinary excretion of potassium from 12.2 +/- 0.7 mEq/24 hr to 0.93 +/- 0.1 and in muscle potassium content from 39.0 +/- 1.0 mEq/100 gm to 22.3 +/- 1.9. By 3 weeks urinary excretion of PGE2 was significantly lower in hypokalemic animals than in controls. Renal cortical, medullary, and papillary PGE2 tissue content decreased significantly, from 0.061 +/- 0.01 microgram/gm to 0.022 +/- 0.005, 0.73 +/- 0.09 microgram/gm to 0.267 +/- 0.036, and 8.6 +/- 1.04 microgram/gm to 4.6 +/- 1.4, respectively. In vitro PGE2 biosynthesis by cortical, medullary, and papillary slices from normal animals was 0.102 +/- 0.01, 9.55 +/- 1.7, and 25.5 +/- 2.8 microgram/gm/30 min, whereas corresponding values from hypokalemic rabbits were 0.04 +/- 0.006, 3.9 +/- 0.747, and 14.0 +/- 1.25 microgram/gm/30 min, respectively. These results indicate that renal slices from hypokalemic rabbits synthesize much less PGE2 in vitro than do normal controls. The date do not support the hypothesis that enhanced PGE2 synthesis mediates the renal concentrating defect of chronic potassium deficiency but suggest that decreased renal PGE2 production may underlie the impairment in renal hemodynamics known to exist in this condition.

Cutis marmorata telangiectatica with multiple congenital anomalies (van Lohuizen's syndrome)

A 5-year-old Korean boy with diagnosis of cutis marmorata telangiectatica congenita had a bluish-red, widespread livedo network over the entire body surface. There was skin atrophy as well as ulceration and crust over some of the lesions. These abnormalities have been associated with mental retardation with abnormal EEG findings, speech disability, defective growth, cleft palate, presence of simian lines and an increase in the atd angles of both palms, diffuse demineralization of bony structure and weakness of the long extensor muscles of both thumbs. Based on our clinical datas and review of world literature, it would seem to be necessary to change the terminology.

Antidiuresis and inhibition of PGE2 excretion by hyperoxia in the conscious dog

Experiments were performed to determine the influence of varying inspired oxygen tension on renal prostaglandin E2 (PGE2) excretion, renal hemodynamics, and water and electrolyte excretion in the conscious dog. Hypoxic exposure (PIO2 = 56 torr) resulted in a 13% increase in renal blood flow (RBF), while hyperoxic breathing with PIO2 of 700, 1426, or 2139 torr, all resulted in significant 5--7% decline in RBF, a response that was significantly attenuated compared to the striking renal vasoconstriction caused by hyperoxia in anesthetized dogs. Hyperbaric oxygenation (HBO) (1426 torr O2, 2139 torr O2) was associated with unexpected decreases in urine flow (V) of 61% and 70%, respectively. The antidiuresis and mild hemodynamic adjustments were correlated with a 67% decline in urinary PGE2 excretion (UPGE2 x V) when the dogs breathed 700 torr O2, while exposure to 1426 torr O2 and 2139 torr O2 diminished UPGE2 x V by 92% and 99%, respectively. Plasma antidiuretic hormone (ADH) concentration, measured during exposure to 1426 torr O2, was unchanged. In addition, this nonpharmacologic hyperbaric decline in PGE2 excretion was not associated with any changes in sodium excretion of renin secretion, in contrast to the usual depression of these variables with pharmacologic PG inhibition (indomethacin). The HBO antidiuresis may be a consequence of an increased medullary osmotic gradient secondary to reduced vasa recta blood flow. Alternatively, this antiduresis could occur as a consequence of a lowering of the normal functional antagonism existing between PGE2 and ADH, such that the influence of endogenous ADH is potentiated.

Indomethacin, salicylates and prostaglandin binding

Aspirin, salicylic acid and indomethacin reversibly inhibit prostaglandin binding to human serum proteins. This effect was demonstrated in the sera of normal subjects and of rheumatoid arthritis patients treated with aspirin as well as by addition of these drugs to serum in vitro. The displacement of serum prostaglandins by salicylate is likely to affect the kinetics of prostaglandin transport and may facilitate the delivery of prostaglandins from serum to tissue receptors.

Stimulation of rabbit renal PGE2 biosynthesis by dietary sodium restriction

Immunoreactive prostaglandin E2 (PGE2) was measured in slices of renal papilla (P), outer medulla (OM), and cortex (C) before and after 30 min of incubation (biosynthesis) in Krebs-Ringer HCO3- buffer in rabbits on low (LS), normal (NS), and high (HS) sodium diets. The 24-h urine PGE2 was also measured daily for 10 days prior to incubation. Daily urine PGE2 was significantly higher (911 +/- 54 ng) in LS, decreasing to 605 +/- 33 at NS, and 558 +/- 48 ng at HS, Initial slice PGE2 was highest in P at LS (35.5 +/- 5.1 MICROGRAMS/G), 5.1 microgram/g), decreasing to 16.9 +/- 1.3 at NS and 18.0 +/- 2.6 micrograms/g at HS. Similar patterns were observed in OM and C, which were quantitatively much lower. PGE2 biosynthesis was highest at LS (P, 139 +/- 21; OM, 58.8 +/- 5.1; C, 0.20 +/- 0.05 micrograms.G-1.30 Min-1) and lowest at HS (P, 58.9 +/- 7.4; OM, 11.8 +/- 3.1; C, 0.07 +/- 0.01 micrograms.g-1.30 min-1). Although PGE2 concentration was higher in P than in OM, the percent increase in OM PGE2 biosynthesis on LS was 3--4 times greater than in P. Since OM is 28% and P is 2% of total renal mass, these results indicate that LS markedly stimulates PGE2 biosynthesis primarily in OM and to a lesser extent in P and C, findings suggesting an important role for OM PGE2 in the renal adaptation to sodium deprivation.

Renal biosynthesis of prostaglandin E2 and F2alpha: dependence on extracellular potassium

Since recent investigations have shown elevated urinary PGE2 and polyuria in hypokalemic animals which were reversed by PG synthesis inhibition with indomethacin, studies were undertaken to examine the effects of extracellular [K+] on renomedullary PG production in vitro. Slices of rabbit and human renal papilla were incubated in Krebs-Ringer HCO3- buffer, 95% O2-5% CO2, glucose 10 mM, HSA 4 gm/100 ml, for 30 min at 38 degrees C, with and without 1-14C-AA (10 micrometer). Measurments were made of total endogenous iPGE2 and iPGF2alpha production and radioactive AA leads to PGE2. In rabbit renal medulla values for iPGE2 (nmol/gm/30 min) were 252 +/- 20 at [K+] 0; 182 +/- 17 at [K+] 2.5 mEq/L; 163 +/- 18 at [K+] 5.5; and 129 +/- 17 [K+] 9.0 (p less than 0.005). iPGF2alpha was unaltered by changes in media potassium concentrations (6.8 +/- 0.9 nmol/gm/30 min at [K+] 0 and 6.2 +/- 0.8 at [K+] 9.0 MEq/L). In the human renal medulla iPGE2 was 9.5 +/- 1.6 nmol/gm/30 min at [K+] 0; 5.0 +/- 0.7 at [K+] 2.5 mEq/L; 5.3 +/- 0.3 at [K+] 5.5; and 4.6 +/- 1.0 at [K+] 9.0 (p less than 0.05). AA leads to PGE2 (nmol/gm/30 min) was 3.21 +/- 0.92 at [K+] 0; 2.47 +/- 0.57 at [K+] 2.5 mEq/L; 1.30 +/- 0.30 at [K+] 5.5; and 0.76 +/- 0.4 at [K+] 9.0 in rabbit medulla (P less than 0.005). It is postulated that direct stimulation of papillary PGE2 biosynthesis by low extracellular [K+] impairing the cAMP-generating response to vasopressin could represent the initial event in the pathogenesis of vasopressin-resistant polyuria.

Cytosine deaminase: structural modifications studies

Structural modification studies have been shown that a cysteine, a histidine and possibly an arginine residue are involved in the catalytic process. The enzyme gave a single band on polyacrylamide gel electrophoresis, and the amino acid analysis showed it to contain a high proportion of hydrophobic residues, which was in agreement with the chemical modification results.

Electrocardiographic changes in scrub typhus patients

Ninety-eight cases of scrub typhus were examined electrocardiographically. Various findings beyond the normal range were as follows: In the febrile stage, sinus arrhythmia with some beats below 60 per minute, flat or low T waves in the left precordial leads, sinus tachycardia, ST segment elevation of 4-l mm in V2, prominent u waves measuring 1 mm or more in amplitude, tall and peaked T waves in V2-4, incomplete right bundle branch block, T wave inversion in V3-4, first degree A-V block, Q-Tc interval prolongation, notched T waves in V3, AV junctional escapes, prominent Ta waves or depression of PR segments in V2, and right axis deviation; in the convalescent stage, sinus arrhythmia with some beats below 60 per minute, prominent u waves measuring 1 mm or more in amplitude, tall and peaked T waves in V2-4, flat or low T waves in the left precordial leads, incomplete right bundle branch block, sinus tachycardia, first degree A-V block, Q-Tc interval prolongation, T wave inversion in V3-4, ST segment elevation of 4 mm in amplitude in V2, ventricular premature contractions, atrial premature contractions, and right axis deviation. In comparison with the electrocardiographic findings in 101 asymptomatic normal subjects, flat T waves in the precordial leads, tall and peaked T waves in V2-4 in both acute and convalescent stages, and sinus arrhythmia with some beats below 60 per minute in the convalescent stage were more frequent in cases. Electrocardiographic abnormalities were present most commonly in the acute illness, and our findings support the impression that, with few exceptions, prompt treatment of scrub typhus with antibiotics prevents the serious cardiac complications seen prior to the antibiotic era.

Renal prostaglandins and the regulation of blood pressure and sodium and water homeostasis

In addition to its well known prohypertensive role in various states of experimental and human hypertension, the kidney has also been shown to exert an antihypertensive "endocrine" function. According to this hypothesis, certain forms of experimental and human hypertension might not solely be the result of an excess in the activity of such renal pressor systems as the renin-angiotensin system and the sympathetic nervous system, but might also result from an absolute or relative deficiency of intra-renal vasodilator antihypertensive factors which might allow pressor systems to act unopposed to produce peripheral arteriolar vasoconstriction and sustained hypertension. At least four factors have been characterized in the kidney of various animal species and man which might be responsible for such an antihypertensive function. These are (1) the renomedullary prostaglandins (PGs), (2) the renomedullary antihypertensive neutral lipid, (3) antirenin phospholipid and (4) the renal kinins. This review is restricted to an examination of the possibility that the vasodepressor renomedullary prostaglandins (PGA and/or PGE) may, at least in part, mediate the so-called antihypertensive function of the kidney and participate in the regulation of renal blood flow and natriuresis by physiologic antagonism of various renal vasoconstrictor stimuli such as the renal renin-angiotensin and the sympathetic nervous systems.

Prostaglandins and asthma: The use of blood components for metabolic studies

Experiments were carried out to study a possible role of prostaglandins (PGs) in the pathogenesis of human bronchial asthma. Leukocyte, plasma, and serum of ambulatory asthmatic as well as nonasthmatic individuals were used. PGF was measured by competitive radioimmunoassay with anti-PGF2alpha antibody. It was found that PGF was spontaneously released from the leukocytes of both asthmatic and nonasthmatic individuals. The PGF release as studied with the cells of asthmatic individuals was enhanced by the additions of arachidonic acid and/or dibutyryl cyclic AMP. Antigenic challenge of sensitive cells failed to show any general effect on the amount of PGF released. The amount of spontaneously released PGF had no correlation with the amount of maximal antigenic histamine release. Preincubation of the cells with arachidonic acid had no effect on subsequent antigenic histamine release. Plasma PGF levels in nonasthmatic and in asthmatic individuals were not significantly different and both were considerably lower than the serum levels. The mean serum PGF level in the asthmatic group was higher than in the nonasthmatic, indicating probably a greater release of PGF from blood cells.

Antagonism of the effects of furosemide by indomethacin in normal and hypertensive man

Furosemide and the prostaglandin synthetase inhibitor, indomethacin, were administered singly and in combination to four normal subjects and six patients with essential hypertension in order to determine whether the antihypertensive, natriuretic and other effects of furosemide could be altered by inhibition of prostaglandin synthesis. In all subjects indomethacin treatment alone resulted in a significant elevation of blood pressure and a fall in plasma renin without any change in sodium excretion. Furosemide alone resulted in a significant blood pressure fall with a rise in plasma renin and urinary aldosterone with a marked increase in urinary sodium loss. These effects were either obviated or blunted by addition of indomethacin. The results are compatible with hypothesis that the antihypertensive and natriuretic effects of furosemide might be mediated at least in part by prostaglandin synthesis. In addition, the effects of indomethacin should be considered when using this drug in hypertensive patients and in subjects requiring diuretic therapy.

Transient neonatal hypocalcemia, hypomagnesemia, and high serum parathyroid hormone with maternal hyperparathyroidism

Findings in a case of neonatal tetany in a child whose mother had elevated blood parathyroid hormone levels because of a parathyroid adenoma are given. The child was found to have hypocalcemia, hypomagnesemia, and hyperphosphatemia. Parathyroid hormone in the infant was found to be elevated. It has been postulated that the pathophysiologic mechanism of the hypocalcemia in this syndrome is transient hypoparathyroidism. The present case suggests a different mechanism: hypomagnesemia and end-organ refractoriness to parathyroid hormone, a state analogous to pseudohypoparathyroidism.