Gonadotropin-induced accumulation of 4,4-dimethylsterols in mouse ovaries and its temporal relation to meiosis.

The resumption of oocyte meiosis is triggered by a number of 4,4-dimethylsterols termed meiosis-activating sterols (MAS). The levels of meiosis active (follicular fluid [FF]-MAS and bull testes [T]-MAS) and inactive (lanosterol) 4,4-dimethylsterols, free cholesterol, and progesterone were determined in gonadotropin-primed prepubertal mouse ovaries in vivo by high-performance liquid chromatography. Ovaries responded to an ovulatory stimulation by increasing their content of 4,4-dimethylsterols but not of free cholesterol.

Hydrogen sulfide and colonic epithelial metabolism: implications for ulcerative colitis.

Hydrogen sulfide (HS-) impairs the oxidation of butyrate in colonocytes and is found in excess in feces of patients with ulcerative colitis. The possible pathogenic role of HS- in ulcerative colitis was further investigated. To investigate the metabolic effect of free and bound fecal HS-, isolated rat colonocytes were incubated in the presence of butyrate without and with the addition of (1) HS- in water, (2) sterile filtrates of fecal homogenates supplemented and incubated with HS- and known sources of fecal HS- production, and (3) HS- incubated with fecal agents known to bind HS-.

Content of meiosis activating sterols in equine follicular fluids: correlation to follicular size and dominance.

Meiosis activating sterols (MAS) are pre-cholesterol sterols that can be isolated from follicular fluid (FF-MAS) or testes (T-MAS). Meiosis activating sterols trigger the resumption of meiosis in cultured meiotically competent oocytes. In the present work MAS, cholesterol and progesterone were assayed by HPLC in follicular fluids collected from pony mares at fixed days after the last ovulation.

In vivo absorption of medium-chain fatty acids by the rat colon exceeds that of short-chain fatty acids.

Background And Aims: Short-chain fatty acids (SCFAs) are main fuels of the colonic epithelium, and are avidly absorbed by the colon of animal and man. The current knowledge on colonic metabolism and absorption of medium-chain fatty acids (MCFAs) is limited. In some clinical situations, colonic absorption of high-energy substances could compensate for reduced absorptive capacity because of a shortened or malfunctioning small bowel.

Plasma disappearance of albumin and impact of capillary thickness in idiopathic dilated cardiomyopathy and after heart transplantation.

BACKGROUND-The increased plasma disappearance of albumin has previously been described in decompensated congestive heart failure (CHF); this disappearance normalized after diuretic treatment. Cardiac transplantation (HTX) and current medical treatment affect microvascular structure and function. We investigated the plasma disappearance of albumin and the impact of microvascular thickness and electrostatic properties in patients with compensated CHF and after HTX.

Plasma clearance of polyfructosan and extracellular body fluid distribution in idiopathic dilated cardiomyopathy and after heart transplantation.

The total extracellular fluid volume and distribution in plasma and interstitial spaces, and the microvascular permeability properties were studied in 16 nonedematous patients with congestive heart failure (CHF) due to idiopathic dilated cardiomyopathy and 17 such patients who underwent heart transplantation (HT) by analyzing the 3-hour plasma disappearance curve of polyfructosan. Eighteen healthy subjects served as controls. Polyfructosan (3.

Apoptosis and formation of peroxynitrite in the lungs of patients with obliterative bronchiolitis.

Background: Obliterative bronchiolitis (OB) is the principal long-term complication of lung and heart-lung transplantation. OB is characterized histologically by inflammation, epithelial cell loss, fibrosis, and obliteration of the terminal airways. The contribution of apoptosis and peroxynitrite formation in OB was examined and assessed whether immunohistochemical markers of these reactions in transbronchial biopsy specimens were predictive of OB development.

Assessment of continuous skeletal muscle blood flow during exercise in humans.

The ability to measure regional blood flow from exercising skeletal muscles is of great interest. However, noninvasive techniques such as venous occlusion plethysmography and pulsed Doppler duplex ultrasonography only allow determination of blood flow at rest. The aim of our study was to investigate the influence of position on continuous measured skeletal muscle blood flow response in the upright and supine positions during graded maximal exercise by means of the local (133)Xenon washout technique with portable CdTe(Cl) detectors.

Calf blood flow during prolonged tilt in idiopathic dilated cardiomyopathy and after cardiac transplantation.

In severe congestive heart failure (CHF), abnormal reflex control of calf blood flow during brief head-up tilt that appears to normalize after transplantation (HTX) may be present during prolonged observation also. Therefore, we studied the effect of prolonged (30 min) 50 degrees head-up tilt on calf skeletal muscle blood flow measured by the local (133)Xe washout method in CHF and after HTX and in patients with the presence vs. absence of native right atrium (+PNA and -PNA, respectively).

Effects of passive tilting on capillary filtration in the lower leg in idiopathic dilated cardiomyopathy and after heart transplantation for the same condition.

Abnormal reflex control of the peripheral microvasculature during orthostasis in congestive heart failure (CHF) and after heart transplantation (HT) may cause failure of microvascular homeostasis and peripheral edema. We explored the effect of passive head-up tilt on lower leg capillary filtration measured by strain-gauge plethysmography in 24 patients with CHF, in 20 patients after HT (12 patients with preserved native right atrium, 8 patients without native right atrium), and in 18 controls. We hypothesized that an impaired peripheral microvascular reflex during orthostasis in CHF and HT might allow increased arterial hydrostatic pressure to increase pressure at the capillary level.

A randomized clinical trial of alpha(1)-antitrypsin augmentation therapy.

We have investigated whether restoration of the balance between neutrophil elastase and its inhibitor, alpha(1)-antitrypsin, can prevent the progression of pulmonary emphysema in patients with alpha(1)-antitrypsin deficiency. Twenty-six Danish and 30 Dutch ex-smokers with alpha(1)-antitrypsin deficiency of PI*ZZ phenotype and moderate emphysema (FEV(1) between 30% and 80% of predicted) participated in a double-blind trial of alpha(1)-antitrypsin augmentation therapy. The patients were randomized to either alpha(1)-antitrypsin (250 mg/kg) or albumin (625 mg/kg) infusions at 4-wk intervals for at least 3 yr.

Influence of feces from patients with ulcerative colitis on butyrate oxidation in rat colonocytes.

An impaired oxidation of butyrate has been suggested as a causative factor of ulcerative colitis and, moreover, agents present in colonic luminal contents impair butyrate oxidation in both rat and human colonocytes. To evaluate the overall effect of feces on the production of CO2 and ketone bodies from butyrate oxidation in rat colonocytes, fecal homogenates from 10 healthy subjects and 10 patients with quiescent and 10 patients with active ulcerative colitis were sterile filtrated and added to rat colonocytes incubated with 2, 4, and 10 mmol/liter of stock butyrate, respectively. Addition of fecal filtrate from healthy subjects and patients with quiescent and active ulcerative colitis to colonocytes incubated with 2, 4, and 10 mmol/liter of stock butyrate, respectively, tended to decrease the production of CO2 from butyrate oxidation, whereas ketogenesis was unaffected.

Pentoxifylline inhibits neointimal formation and stimulates constrictive vascular remodeling after arterial injury.

Pentoxifylline (PTX) is a phosphodiesterase inhibitor used in the treatment of peripheral vascular disease, and this agent can suppress inflammatory vascular damage. Inflammation has been implicated in vascular lesion formation, and we examined the effects of PTX in a model of arterial injury. Sprague-Dawley rats were treated with intraperitoneal PTX (75 mg/kg/day) or saline starting 3 days before carotid balloon injury, and killed 24 h or 14 days later.

Quantitation of meiosis activating sterols in human follicular fluid using HPLC and photodiode array detection.

A chromatographic assay for 4,4-dimethyl-5alpha-cholesta-8,14, 24-triene-3beta-ol (FF-MAS), and its reduced species, 4, 4-dimethyl-5alpha-cholesta-8,24-triene-3beta-ol (T-MAS), has been established for analysis of human follicular fluid (huFF). The assay also quantifies lanosterol, free cholesterol and progesterone. It was established using a pool of more than 100 individual follicular fluids from women undergoing in vitro fertilization treatment.

Endothelin and von Willebrand factor as parameters of endothelial function in idiopathic dilated cardiomyopathy: different stimuli for release before and after heart transplantation?

Background: Congestive heart failure (CHF) and heart transplantation (HTX) are characterized by endothelial dysfunction as indicated by elevation of markers of endothelial function, including endothelin and von Willebrand factor (vWF). However, previous studies included both patients with idiopathic dilated cardiomyopathy and ischemic heart disease; the latter condition shows endothelial dysfunction, per se. The 2 endothelial factors have different origin and may provide different information about endothelial dysfunction in CHF and after HTX caused by idiopathic dilated cardiomyopathy.

Comparison of diarrhea induced by ingestion of fructooligosaccharide Idolax and disaccharide lactulose: role of osmolarity versus fermentation of malabsorbed carbohydrate.

Whether carbohydrate malabsorption causes diarrhea probably depends on the balance between the osmotic force of the carbohydrate and the compensatory capacity of the colon to dispose of the carbohydrate by bacterial fermentation. The present study evaluated the specific role of the osmolarity by comparing the severity of diarrhea after ingestion of two nonabsorbable carbohydrates, the fructooligosaccharide Idolax and the disaccharide lactulose. Both carbohydrates are readily fermented by the colonic flora but differ in osmolarity, the osmotic force being twice as high for lactulose as for Idolax.

Long-range correlations of serial FEV1 measurements in emphysematous patients and normal subjects.

In obstructive lung disease the annual change in lung function is usually estimated from serial measurements of forced expiratory volume in 1 s (FEV1). Frequent measurements in each patient may not improve this estimate because data are not statistically independent; i.e.