Detection of immunoglobulin M in cerebrospinal fluid from syphilis patients by enzyme-linked immunosorbent assay

Cerebrospinal fluid (CSF) samples were evaluated in an immunoglobulin M enzyme-linked immunosorbent assay (IgM ELISA) for syphilis with sonic extracts of Treponema pallidum coated on polystyrene plates. The ELISA procedure was reproducible, and T. pallidum antigens were stable., A total of 15 CSF samples from patients with neurosyphilis, 18 CSF samples from patients with syphilis, 12 CSF samples from patients treated for syphilis, and 494 CSF samples from patients with neurologic or other systemic diseases were tested. The IgM ELISA gave reactive results in all of six symptomatic and congenital neurosyphilitic patients and none of nine asymptomatic neurosyphilitic patients. Of 524 CSF samples from nonneurosyphilitic individuals, 513 were nonreactive, resulting in 98% test specificity. The IgM ELISA in CSF should prove to be useful for confirmation of symptomatic neurosyphilis.

Alkylating agents: in vitro studies of cross-resistance patterns in human cell lines

The alkylating agents represent one of the most important classes of antitumor agents and play a major role in combination with other agents in the curative chemotherapy of selected human cancers. By repeatedly exposing cells to escalating doses of an alkylating agent, we have developed four human tumor cell lines which are relatively stably resistant to the drug with which the culture was treated. The response of these cell lines to a variety of alkylating agents was compared to the response of the parent cell lines to the same drug. The Raji/HN2 line was 7-fold resistant to nitrogen mustard and about 3-fold resistant to 4-hydroxyperoxycyclophosphamide, but it was not resistant to N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU), melphalan (MEL), busulfan, trimethyleneiminethiophosphoramide, 4-hydroperoxyifosfamide, or cisplatin [cis-diamminedichloroplatinum(II)] (CDDP). The Raji/BCNU line was 5.3-fold resistant to BCNU and 4-fold resistant to both MEL and CDDP. The Raji/CP line was 7-fold resistant to CDDP and 3-fold resistant to both nitrogen mustard and BCNU, but it was not resistant to busulfan, trimethyleneiminethiophosphoramide, or 4-hydroperoxyifosfamide. The SCC-25/CP line, which was 12-fold resistant to CDDP, was 5-fold resistant to MEL and 3-fold resistant to 4-hydroxyperoxycyclophosphamide. The SCC-25/CP line was almost 24-fold resistant to methotrexate after 30-min treatment and about 7-fold resistant to methotrexate after continuous treatment. None of the other cell lines was resistant to methotrexate. The survival of SCC-25 and SCC-25/CP cells exposed to several antineoplastic agents was examined over several logs of survival. The SCC-25/CP cells are highly resistant to CDDP; the ratio of the slopes of the survival curves (SCC-25/CP to SCC-25) of the two lines was 43. At survivals of 1%, resistance to MEL and BCNU became evident in the SCC-25/CP line. At survivals of 0.1%, resistance to mitomycin C and, to a lesser degree, to Adriamycin and vincristine was evident. It is more difficult to produce resistance to alkylating agents, even with extended selection pressure, than to other antineoplastic drugs such as antimetabolites and natural products. We found no evidence of pleiotropic resistance in any alkylating agent-resistant cell line. Our results suggest that a judicious choice of alkylating agents given in sequential or concurrent combination may be a rational treatment strategy with potential applications in the clinic.

Sonographic evaluation of inferior vena caval obstruction: correlative study with vena cavography

Sonographic findings of obstruction of the inferior vena cava (IVC) in 14 cases are described and correlated with venographic findings. The causes of the obstruction were membrane (five cases), thrombosis (three), and intraluminal tumor invasion by hypernephroma, hepatoma, and adrenal carcinoma in six. Sonographic examination revealed highly echogenic segmental obliteration or membrane in membranous obstruction and echogenic intraluminal mass in thrombotic occlusion. Absence of an identifiable patent lumen in a technically satisfactory study was another finding in thrombotic obstruction. On real-time sonograms, the normal respiratory changes of the IVC were absent when there was complete occlusion. Transhepatic collaterals, patency of other segments of the IVC, and associated malignancy were additional sonographic findings. Comparison to venography suggested that in addition to ease and safety, sonography has advantages in delineation of the cephalad extent of occlusion, dynamic evaluation of the IVC below the obstruction, and the simultaneous evaluation of adjacent organs.

Estradiol stimulates rat renopapillary prostaglandin E2 (PGE2), but not PGF2 alpha biosynthesis

The effects of estrogen on renal prostaglandin (PG) and renin-angiotensin were investigated in rats in relation to sodium metabolism and blood pressure regulation. Regardless of estrous cycle phase, PGE2 urinary excretion in females was 2-3 times higher than that in males and was associated with higher sodium excretion. A positive correlation was observed between urinary PGE2 and free estradiol concentrations. Reno-papillary PGE2 synthesis in vitro after slice incubation was higher in estrous females than in males. Ovariectomy resulted in a marked decrease in PGE2 renal synthesis and excretion, and estradiol administration (50 micrograms, im) restored these to levels comparable to those in cycling females. This estradiol treatment also was associated with a 3-fold rise in PRA without alteration in blood pressure. In estrogen-primed ovariectomized rats, infusion of the angiotensin antagonist Sar1-Ala8-angiotensin II at a rate of 30 micrograms/microliter X h resulted in a further rise in PRA as well as a significant decrease in renal PGE2 synthesis and excretion toward values observed in the ovariectomized animals. In contrast, renal synthesis and excretion of PGF2 showed no fluctuations during identical variations in estrogenic states. The results suggest that estradiol stimulates renal PGE2, but not PGF2 alpha, synthesis not only via a direct stimulatory action, but also through augmentation of the renin-angiotensin II axis. This increase in vasodilatory PGE2 may function to offset the prohypertensive effects of the estrogen-stimulated renin-angiotensin axis.

Hypertension in experimental diabetes mellitus. Renin-prostaglandin interaction

To investigate mechanisms involved in the high incidence of hypertension in diabetes mellitus, the relationship between renin-angiotensin production and renal prostaglandin E2 synthesis was studied in rats 1 week after diabetes mellitus had been induced by streptozotocin injection. The diabetic rats became hypertensive, although plasma renin activity did not increase despite the plasma volume contraction resulting from polyuria and natriuresis. Subcutaneous insulin injection resulted in a marked increase in plasma renin activity, while more rigid control of diabetes mellitus achieved by constant insulin infusion decreased blood pressure. Cortical renin content and renin release as well as papillary prostaglandin E2 synthesis in vitro were significantly lower in diabetic rats than in nondiabetic controls. Isoproterenol and prostaglandin E2 stimulated renin release in controls, while diabetic rats responded only to isoproterenol. Insulin infusion by pump reversed these abnormalities. An additive effect of a maximum dose of isoproterenol (10(-5) M) and prostaglandin E2 (10(-4) M) on renin release was observed in nondiabetic controls and in diabetic rats treated with insulin pump, but not in untreated diabetic rats. The results suggest that 1) renal renin release and prostaglandin E2 synthesis in diabetes mellitus are insulin dependent, 2) inappropriately lower plasma renin activity in diabetes mellitus may be attributed to a diminished renal renin pool and a lack of renin release in response to renal prostaglandin E2, the synthesis of which is also impaired in diabetes, prostaglandin E2-induced renin release may operate independently from isoproterenol-induced renin release, and impaired renal prostaglandin E2 synthesis may contribute to the development of hypertension in the face of an unchanged prohypertensive renin-angiotensin II system.

Radiosensitization of EMT6 cells by four platinum complexes

The greatest research effort in producing radiation sensitizers has been directed toward organic compounds. However, platinum complexes also have radiosensitizing capabilities, perhaps because they bind to DNA. The compound described here are dichloro complexes of bivalent platinum with one or two potentially radiosensitizing ligands. The radiosensitization of oxygenated and hypoxic exponentially growing EMT6 cells in vitro was measured. The dose modifying factors obtained with 200 microM and 400 microM trans-bis(2-nitroimidazole)dichloroplatinum II (NIPt) in hypoxic cells were 1.5 and 2.1, respectively. For trans-bis(2-amino-5-nitrothiazole)dichloroplatinum II (Plant) under the same conditions, the dose modifying factor was 1.5 at 200 microM and 1.8 at 400 microM. Neither compound sensitized oxygenated cells when tested similar protocols. Unlike the trans complexes, (1,2-diamino-4-nitrobenzene)dichloroplatinum II (Plato) was cytotoxic toward the hypoxic cells in the absence of X rays. The time course of cytotoxicity for 100 microM Plato in exponentially growing cells showed rapid killing of hypoxic cells, and much less toxicity toward oxygenated cells. In radiosensitization studies, dose modifying factors of 1.6 and 2.0 were found with 200 microM and 400 microM Plato in hypoxic cells. The compound did not sensitize aerobic cells. The well-known platinum complex cis-dipyridinedichloroplatinum II (PyPt) represents a cis-platinum heterocyclic aromatic complex that does not have a nitro-functionality. The dose modifying factor obtained with 400 microM PyPt in hypoxic cells was 1.7. On a molar basis, the nitro-functional platinum complexes appear to be more effective as hypoxic cell radiosensitizers than the corresponding free ligands.

Effects of indomethacin on blood flow in the normal pancreas in conscious dogs

In anesthetised animals basal pancreatic blood flow, both in the normal gland and in acute pancreatitis, and basal renal blood flow have been shown to be dependent on prostaglandins (PGs). However, in conscious dogs it has been demonstrated that the reliance of basal renal blood flow on PGs is only apparent, and probably due to the effect of anesthesia and surgery stimulating PG synthesis through enhanced stimulation of the sympathetic nervous system. This study was undertaken to investigate the changes in mean blood pressure, cardiac output, and pancreatic arterial blood flow, relative to the cardiac output, in the normal pancreas, with and without PG synthesis inhibition (indomethacin) in conscious dogs. Blood flows were measured with electromagnetic flow probes. The effects of indomethacin were measured over a 2-hr period and compared to a control group. The results show that the relative pancreatic blood flow is not affected by doses of indomethacin which decrease cardiac output (P less than 0.5). It is suggested that PGs may have no effect on blood flow in the normal pancreas in conscious animals.

Mechanism of furosemide-induced natriuresis by direct stimulation of renal prostaglandin E2

Studies were conducted to investigate the interaction of renal prostaglandin E2 (PGE2) production and the renin-angiotensin system in the mechanism of furosemide-induced natriuresis. In conscious rabbits with permanent urinary bladder cannulation, furosemide in vivo (10 mg/kg) increased urinary water, sodium, and PGE2 excretion and plasma renin activity (PRA) over 50 min. Furosemide administered in vivo enhanced renal papillary but not cortical in vitro PGE2 biosynthesis. Prior administration of indomethacin at 2 mg/kg augmented the saluretic effect of furosemide, decreased its effect on UPGE2 V, abolished the rise in PRA, and reduced cortical but not papillary PGE2 biosynthesis. However, at 10 mg/kg, indomethacin reduced the saluretic effect of furosemide and eliminated the increase in UPGE2 V with continued suppression of PRA. Direct addition of furosemide in vitro to the incubation medium (10(-5) and 10(-3) M) markedly augmented papillary PGE2 synthesis. It is concluded that furosemide stimulates renal papillary PGE2 biosynthesis directly without mediation by angiotensin II, resulting in an increase in UPGE2 V, and the enhanced or inhibitory effect of indomethacin on furosemide-induced natriuresis is dose related and dependent on the degree of PGE2 synthesis inhibition in the presence of suppressed PRA, which occurred at all doses studied.

Absent or delayed preovulatory luteinizing hormone surge in experimental diabetes mellitus

The proestrus preovulatory luteinizing hormone (LH) surge was absent or delayed in more than 56% of untreated streptozotocin-diabetic rats. Absence of LH surge was associated with anovulation. Insulin treatment for 10-14 days restored the diminished surge and ovulation frequency. Pituitary LH release in response to exogenous gonadotropin-releasing hormone administration in diabetic rats was not different from controls. Impaired hypothalamic function may comprise the basis for the increased incidence of infertility in diabetes mellitus.

Prostaglandin E2 production by human tumors. Defense mechanism against the host? A preliminary report

Immunoreactive PGE2 was determined in 11 surgically removed malignant tumors. When compared to adjacent non-malignant tissues PGE2 content was significantly higher in the neoplastic tissues. These findings support the view that PG may play a role in cell proliferation and/or vascular supply to tumor tissues. The hypothesis was also discussed that PGE2 may represent a tumor against host defense since it can decrease spontaneous and antibody dependent cytotoxicity. PGE2 may also play a role in tumor induced osteoporosis and hypercalcemia. If this hypothesis is correct PGE2 synthesis inhibitors may be employed as auxiliary antitumor agents.

Metagonimiasis in Korea

Of the intestinal trematode infections in Korea, metagonimiasis is the most important under public health aspects. In a nationwide survey in 1981, at least 450,000 people (1.2%) were found infected. The endemic areas are scattered along rivers which run to the southern and eastern coast, where more than 20% of villagers are commonly infected. The snail hosts of Metagonimus yokogawai are either Semisulcospira spp. or Koreanomelania spp. The fish hosts are sweetfish (Plecoglossus altivelis) and many species of cyprinid fish, of which the former is the more important source of infection. Dog, cat and rat are found naturally infected in endemic areas. Sweetfish frequently have more than 10,000 metacercariae in their muscles. In autumn, the metacercarial burden reaches its zenith, when the fish is sweetest. Eating only one raw sweetfish may result in severe abdominal pain, prostration and watery diarrhoea, However, in endemic areas, many egg discharging cases rarely suffer from diarrhoea and abdominal pain. The symptoms seem mainly to depend on the degree of infection. But also duration of infection seems to be a factor which determines the intensity of symptoms. In experimental infection of cat or dog, juvenile worms thrive into crypts of Lieberkühn in the jejunum for about 5 days. Thereafter, the adults move to the intervillous space and destroy the enterocytes. Adults rarely reach the submucosa or lymphatic tissues. In rather heavy infection, mucosal damage such as villi fusion, villi shortening, slight hypertrophy of crypts, goblet cell depletion, inflammatory cell infiltration and shortening of microvilli were observed. These pathologic findings regress within 4 weeks of infection though adult worms still live in the mucosa.

Symptomatic neurosyphilis

We observed 24 patients with symptomatic neurosyphilis. Of these 24 patients, nine had clinical manifestations of general paresis, seven tabetic neurosyphilis, five meningovascular neurosyphilis, one taboparetic, one tabomeningovascular, and one spinal neurosyphilis. Confusion, disorientation, lancinating pain, impaired memory, and bizarre behavior were the most prevalent symptoms. Sensitivity of the CSF FTA-ABS test was higher (96%) than that of the CSF VDRL test (79%). CSF cell count and total protein determination may be inadequate for assessing activity of neurosyphilis.

Vitamin A in human skin: II Concentrations of carotene, retinol and dehydroretinol in various components of normal skin

Pro-vitamin A(beta-carotene) and the predominant forms of vitamin A in human skin (retinol and dehydroretinol) were analyzed in hydrolyzed specimens from 4 cadavers and 22 healthy subjects. Beta-carotene was identified in extracts of epidermis by its specific absorption spectrum. Vitamin A was determined by high-pressure liquid chromatography. The concentrations were related to the wet weight or protein content of the sample. The analysis of different skin compartments showed that the concentrations of the 3 constituents were usually related as follows: carotene greater than retinol greater than dehydroretinol. The concentrations were always higher in the epidermis than in the upper dermis. Skin surface lipids contained carotene and retinol but not in amounts sufficient to contribute to the higher epidermal values. Analysis of epidermal autopsies from 5 different skin areas (back, breast, arm, leg and foot) and of epidermal biopsies from the back of the healthy subjects showed that the interindividual differences were larger for carotene and dehydroretinol than for retinol, whereas the intraindividual variations were larger for retinol. The mean (+/- SD) concentrations of carotene, retinol and dehydroretinol in back skin epidermis of healthy subjects were 13 +/- 5, 1.7 +/- 0.4 and 0.4 +/- 0.2 microgram/g protein, respectively. No significant variations with age and sex were found.

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.

Renal prostaglandins

The renal prostaglandins PGS2 and PGE2 possess potent antihypertensive and vasodepressor activity. The mechanism of blood pressure lowering effect is through peripheral arteriolar dilation with a fall in total peripheral resistance. PGA unlike PGE escape degradation by the lung and thus could circulate as antihypertensive hormones. Since plasma PGA levels rise in humans on a low sodium intake, it has been postulated that the beneficial effects of a low sodium diet in some hypertensives may be the result of an increase in peripheral vasodilating PGA. Support that plasma PGA may be a regulator of systemic blood pressure is also derived from the fact a PGA-secreting renal tumor was associated with a fall in blood pressure and a rise in plasma PGA in a previously hypertensive woman. The removal of the tumor resulted in a return of blood pressure to elevated levels and a concomitant fall in PGA. Recently, a number of human patients with essential hypertension have been infused with PGA1 and PGA2. It was observed that there was an initial increase in renal blood flow, sodium and water excretion which was associated with no change in the elevated blood pressure. When blood pressure ultimately fell, there was a return of renal blood flow, sodium and water excretion to preinfusion levels. It would appear that PGA compounds act as 'ideal' antihypertensive agents since they favorably effect renal resistance, sodium and water homeostasis, plasma volume, total peripheral resistance, blood pressure and indirectly cardiac output through baroreceptor stimulation, all factors known to be important in etiology in human hypertension.

Radioimmunoassay of prostaglandin A. Intrarenal PGA2 as a factor mediating saline-induced natriuresis

A highly specific, sensitive (25 pg) radioimmunoassay for prostaglandin A is described; the assay is characterized by high reproducibility (coefficient of variation 1-2%) and low cross-reactivity with respect to PGE 1 and PGE 2 (10%), PGB 2 (15%), and PGF 2α (0.01%). High specificity for PGA was obtained by chromatographic separation of the prostaglandins. Since it has been suggested that PGA is a natriuretic "hormone," the concentration of PGA in the renal cortex, outer medulla, and papilla was determined in rabbits on low-sodium and high-sodium diets in the presence and the absence of the prostaglandin synthetase inhibitor indomethacin. In rabbits on the low-sodium diet (12 mEq/24 hours). PGA2 was 15 ± 4 pg/mg in the cortex, 502 ± 67 pg/mg in the outer medulla, and 3740 ± 640 pg/mg in the papilla. In rabbits on saline loading (56 mEq/24 hours), cortical and outer medullary PGA2 rose to 32 ± 6 pg/mg and 1275 ± 290 pg/mg, respectively, but papillary PGA decreased to 1842 ± 480 pg/mg. PGA concentration in the outer medulla and papilla was markedly inhibited by indomethacin (50 mg/day), and this inhibition was associated with sodium retention. The results indicated that sodium induced papillary synthesis of PGA and intrarenal circulation of the prostaglandin to the outer medulla and the cortex possibly via the long veins of the outer medulla occurred. The results are compatible with PGA 2 involvement in salineinduced natriuresis.