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Biomedical subjects

N Krivoy

Publications and source records attributed to N Krivoy.

At least 19 recordsLinked to original sources

Generation of angiotensin II from human plasma by tissue kallikrein.

1. Human plasma was incubated with tissue kallikrein from porcine pancreas, dialysed to obtain a fraction with a molecular mass < 10 kDa and further purified by reverse-phase chromatography. 2. Vasopressor activity in the fractions obtained was tested in the isolated perfused rat kidney. 3. In one fraction a strong vasopressor action was found, which was blocked by saralasin and by an angiotensin II antibody. 4. Aprotinin inhibited the formation of vasopressor substances by tissue kallikrein. 5. U.v.-laser desorption/ionization mass spectrometry revealed a molecular mass of 1046 Da in the purified active fraction. 6. It is concluded that tissue kallikrein forms not only kinins, but also angiotensin II, from human plasma under physiological conditions.

Angiotensin II

Endogenous digoxin-like immunoreactivity measured in seminal fluid from a normal male population.

Endogenous digoxin-like immunoreactivity (EDLI) has been detected in different biological fluids and in several pathophysiological conditions. In this study, using radioimmunoassay we reported for the first time the existence of bound and unbound EDLI in normal seminal fluid. The unusual finding was the detection of unbound EDLI in the seminal fluid, while this reactivity was undetected in plasma. Two main hypotheses are presented: (1) local secretion of unbound EDLI and/or (2) passive diffusion from plasma to the seminal fluid of unbound EDLI and subsequent local concentration.

Adult

Peripartum changes in free and protein-bound digoxinlike immunoreactive factor.

The appearance of free digoxinlike immunoreactive factor in pregnancy and its rapid disappearance after delivery is well documented. The protein-bound fraction, a common component of plasma, does not change during pregnancy. We investigated the peripartum changes in both free and protein-bound fractions of digoxinlike immunoreactive factor and observed different peripartum patterns of those fractions. While the disappearance of the free fraction after delivery was reconfirmed, the protein-bound fraction exhibited a biphasic pattern: a rapid decrease after delivery with a slow increase to predelivery levels seven weeks later. The disappearance of free digoxinlike immunoreactive factor after delivery may reflect the elimination of the fetal source. The changes in the protein-bound fraction imply that the fraction may also vary in certain clinical situations and may be produced in response to certain homeostatic changes and suggest a possible interaction between fetal and maternal systems that produce digoxinlike immunoreactive factor during pregnancy.

Blood Proteins

[Transient liver damage due to prajmalium bitartrate].

3 patients developed transient cholestatic jaundice after administration of prajmalium bitartrate, a class I antiarrhythmic drug. The leukocyte inhibition tests showed 4%, 12% and 15% inhibition, respectively, while eosinophilia was seen in all 3, supporting the assumption that the transient hepatic damage was due to drug exposure. Discontinuing the drug resulted in improvement in the clinical and biochemical findings.

Adult

Endogenous digoxin-like immunoreactivity in follicular fluid and in vitro fertilization.

Plasma digoxin-like immunoreactive factor (DLIF) has been detected in various pathophysiological conditions associated with volume expansion. In this study, using radioimmunoassay, we confirmed the existence of high levels of DLIF in the stimulated follicular fluid, a rapidly volume-expanding biological model. The concentration of the various fractions of DLIF in follicular fluid was 2-9 times higher than in plasma, suggesting local concentration or production. No difference in concentration was observed between follicles containing fertilized oocytes and follicles with unfertilized oocytes. The role of DLIF in follicular homeostasis remains to be further investigated.

Blood Proteins

Native valve Staphylococcus epidermidis endocarditis: report of seven cases and review of the literature.

This report describes seven patients from three university hospitals whose native valve infective endocarditis was caused by Staphylococcus epidermidis. The literature on endocarditis caused by S. epidermidis is also reviewed and the clinical features of patients with native valve endocarditis due to this organism are compared with those of patients from a general series of infective endocarditis cases. Compared with infective endocarditis caused by other organisms, S. epidermidis endocarditis tends to occur more frequently in male patients. Patients with S. epidermidis endocarditis exhibit fewer embolic complications and skin manifestations. The frequency of congestive heart failure is lower in this group. The relative indolent course and apparent rarity of native valve S. epidermidis endocarditis necessitate a high index of suspicion for early diagnosis.

Aged

Total digoxin-like immunoreactive factor(s) in healthy population, uncomplicated term pregnancies and neonates.

Free digoxin-like immunoreactive factor(s) (DLIF) which may have a homeostatic role, as documented in different physiological conditions, but is generally undetectable in plasma from normal population. Total digoxin-like immunoreactive factor(s) (protein bound and free) can be estimated after plasma is heated. In this study, total digoxin-like immunoreactive factor(s) as measured in plasma in a well defined control population and compared to healthy term pregnant women and neonates, categories known to be associated with increased free digoxin-like immunoreactive factor(s) concentrations. The mean level of this factor(s) in the control group was 706 +/- 129 pg digoxin equivalent/ml (pg/ml) and was unaffected by age and sex. Significantly increased levels of total digoxin-like immunoreactive factor(s) were found in pregnant women and neonates (928 +/- 127 and 1242 +/- 367 pg/ml, respectively). We conclude that levels of total digoxin-like immunoreactive factor(s) are increased in term pregnancies and neonates, similarly to its free form. However total digoxin-like immunoreactive factor(s) is detected in the normal population as a plasma component, contrary to its free form, which is generally undetectable.

Adult

A common-source outbreak of fulminant hepatitis B in a hospital.

A nosocomial outbreak of fulminant hepatitis B infection at a medical center in Haifa, Israel, between 7 and 26 June 1986, involved five patients who had been hospitalized previously in the medical ward in late April and early May (first generation). This outbreak had an unusual clinical course, with fulminant hepatic failure associated with acute renal failure from acute glomerulonephritis, leading to death within a few days. The onset dates of hepatitis were tightly clustered temporally and incubation periods were short. Extensive laboratory and epidemiologic evaluation showed that the probable common-source vehicle of transmission was a multiple-dose vial of heparin and normal saline flush solution that may have been contaminated by blood of a known HBsAg carrier, who was positive for anti-HBe, hospitalized at the same time. A sixth patient died in August 1986 (second generation), after his initial admission in June that coincided with the terminal hospitalizations of three first-generation patients. Those patients had marked coagulopathies, and transmission to the sixth patient most probably occurred through environmental contamination by patients or through cross-contamination between patients through staff. The unusually high mortality rate (5 of 6) in this outbreak has not been definitely explained.

Aged

Digoxin-like immunoreactive factor(s) in human gonadotropin stimulated follicular fluid.

Plasma digoxin-like immunoreactive factor(s) (DLIF) have been reported in various pathophysiological conditions associated with volume expansion and linked to the regulation of blood volume and pressure. We hypothesized that DLIF might be present in rapidly expanding gonadotropin-stimulated ovarian follicles. The mean total and free DLIF concentrations in the follicles (n = 9) studied were 4925 nmol/L and 1885 nmol/L, respectively. These concentrations were substantially higher than the plasma total and free DLIF levels in these women: 1216 nmol/L and 158 nmol/L, respectively (p less than 0.0001). The plasma DLIF levels in the gonadotropin-treated women were comparable to those in term pregnant women, which are known to be higher than those in non-pregnant women. The ovary thus may be a source of DLIF in the plasma of gonadotropin-treated women, and DLIF may have a role in ovarian follicular fluid homeostasis.

Blood Proteins

Digoxin-like immunoreactive factor in twin and pregnancy-associated hypertensive pregnancies.

The objective of this study was to measure maternal total digoxin-like immunoreactive factor levels in singleton pregnancies with or without hypertension and in twin pregnancies. Plasma digoxin-like immunoreactive factor was measured in 113 third-trimester patients: 51 normotensives, 20 preeclamptics, 19 with latent or chronic hypertension, and 23 with twin pregnancies. The concentration of total digoxin-like immunoreactive factor in the twin gestations (1143 +/- 249 pg/mL) was significantly higher than that in either the normotensive pregnancies (890 +/- 161 pg/mL) (P less than .001) or in the hypertensive pregnancies (903 +/- 256 pg/mL) (P less than .01). However, there were no significant differences in digoxin-like immunoreactive factor levels between the normotensive and hypertensive groups. A trend of higher, although not statistically significant, levels of digoxin-like immunoreactive factor was noted in the chronic hypertensive group as compared with the preeclamptic patients (957 +/- 212 versus 852 +/- 288 pg/mL). We therefore conclude that digoxin-like immunoreactive factor does not contribute significantly to the pathogenesis or prediction of preeclampsia. The increased amount of digoxin-like immunoreactive factor in twin pregnancies may reflect a contribution from multifetal origin, or might be a physiologic adaptive mechanism allowing higher cardiac output by a possible cardiotropic effect.

Adult