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Biomedical subjects

P Penev

Publications and source records attributed to P Penev.

At least 19 recordsLinked to original sources
PubMed1998

High prevalence of sleep disturbance in cirrhosis.

Sleep disturbance is a classic sign of hepatic encephalopathy. However, there are limited data regarding its prevalence in cirrhotic patients without overt hepatic encephalopathy. We assessed the characteristics of sleep in cirrhosis using a sleep questionnaire (n = 44) and actigraphy (n = 20). The results were compared with those of subjects with chronic renal failure and those of healthy controls. Presence of subclinical hepatic encephalopathy, chronotypology profile, and individual's affective state were also analyzed. The questionnaire indicated an elevated number of cirrhotic patients (47.7%) and patients with chronic renal failure (38.6%) who complained of unsatisfactory sleep compared with healthy controls (4.5%, P < .01). Actigraphy corroborated the deterioration of sleep parameters in cirrhotic patients with unsatisfactory sleep. The sleep disturbance in cirrhosis was not associated with clinical parameters nor with cognitive impairment. Cirrhotic subjects and patients with chronic renal failure with unsatisfactory sleep showed higher scores for depression and anxiety, raising the possibility that the effects of chronic disease may underlie the pathogenesis of sleep disturbance. However, in contrast to chronic renal failure, unsatisfactory sleep in cirrhosis was associated with delayed bedtime, delayed wake-up time, and evening chronotypology. In conclusion, a sleep disturbance is frequent in cirrhotic patients without hepatic encephalopathy and may be related to abnormalities of the circadian timekeeping system.

Activity Cycles↗
PubMed1995

Alterations in the circadian system in advanced age.

In addition to light, a variety of non-photic stimuli can induce phase shifts in the circadian clock of rodents. We have examined the effects of advanced age on the response of the circadian clock to both photic and non-photic stimuli in old hamsters (i.e., over 16 months of age). Among the age-related changes in the circadian rhythm of locomotor activity are: (1) alterations in the phase angle of entrainment to the light-dark cycle; (2) an altered response to the phase-shifting effects of light pulses; (3) changes in the time it takes to re-entrain to a new light-dark cycle; and (4) a loss of responsiveness to the phase-shifting or entraining effects of stimuli which induce an acute increase of activity. Many of the effects of ageing on the circadian clock system can be simulated in young animals by depleting brain monoamine levels, suggesting that ageing alters monoaminergic inputs to the clock. Some of the age-related changes in the response of the clock to an activity-inducing stimulus can be reversed by implanting old animals with fetal suprachiasmatic nuclear tissue. Determining the physiological basis of age-related changes in the responsiveness of the clock to both internal and external stimuli, and the mechanisms by which normal circadian functioning can be restored, should lead to new insight into the functioning of the circadian clock and may suggest new approaches to the normalization of disturbed circadian rhythms.

Aging↗
PubMed1995

Effects of age on the circadian system.

While aging has been associated with changes in the period and amplitude of circadian rhythms, little is known about how aging influences the response of the circadian clock to environmental stimuli. In this paper, we report on recent studies designed to determine the effects of advanced age on the response of the circadian clock to both photic and nonphotic stimuli in old hamsters (e.g., over 16 mo of age). Among the most pronounced age-related changes in the circadian rhythm of locomotor activity are: (a) alterations in the phase-angle of entrainment to the light-dark cycle; (b) an increase in the magnitude of phase shifts induced by pulses of light presented at specific circadian times; and (c) a loss of responsiveness to the phase shifting or entraining effects of stimuli which induce an acute increase of activity. Depletion of brain monoamine levels in young animals can induce changes in the responsiveness of the circadian clock to environmental stimuli which are similar to those which occur spontaneously in old animals, suggesting that aging alters monoaminergic inputs to the clock. Some of the age-related changes in the response of the clock to an activity-inducing stimulus can be reversed by implanting old animals with fetal SCN tissue. Determining the physiological basis for age related changes in the responsiveness of the clock to both internal and external stimuli, and the mechanisms by which normal circadian function can be restored, should lead to new insight into the functioning of the circadian clock and may lead to new approaches for normalizing disturbed circadian rhythms.

Aging↗
PubMed1988

[Gamma-glutamyltransferase activity in the serum and the mean-cell erythrocyte volume of patients with chronic ethylism and chronic liver diseases (preliminary report)].

The dynamics of the enzyme gamma-glutamyltransferase (gamma GT) was followed up in 34 patients: 17 patients with liver cirrhosis, 9 patients with chronic hepatitis and 8 patients with liver steatosis. In the patients with alcoholic cirrhosis the activity of gamma GT rapidly fell in hospital conditions which is related to the forced abstinence. In the cirrhotic patients with nonalcoholic etiology no changes in gamma GT activity were found. In the patients with chronic hepatitis and liver steatosis with alcoholic etiology the gamma GT activity resembled that of alcoholic cirrhotic patients. The gamma GT activity fell most sharply in the patients with liver steatosis which is explained by the mild and reversible liver lesions characteristic for this disease. The mean erythrocyte volume determined by electronic blood cell counter shows a tendency toward macrocytosis in all chronic alcoholic patients. Macrocytosis is also found by ordinary microscopic examination of the blood cells.

Adult↗
PubMed1986

[Lipid fraction content of puncture biopsy material from the liver of patients with diabetes mellitus and obesity].

The quantity of the main lipid classes in hepatic tissue has been determined via thin layer chromatography on silica gel, the tissue obtained by blind hepatic biopsy in 20 patients with diabetes mellitus and obesity and in a control group of 5 patients with no hepatic disease. A considerable increase of lipid in liver was established in the patients with diabetes mellitus and obesity-the fraction of neutral lipids mainly. The fatty infiltration of liver in diabetics was accompanied by a considerable increase of triglyceride concentration--3,78 g/100 g wet body mass as compared with the controls--0,95 g/100 g wet body mass. Increased concentration of esters and cholesterol (80%) was established in the liver of the patients with diabetes and obesity as well as increased fraction of free fatty acids (230%). The concentrations of total phospholipids and free cholesterol in liver in both groups of patients proved to be rather close. The fatty infiltration of liver of diabetics with obesity was accompanied by marked increase of percentage content of triglycerides--from 17.3% in the control group to 42.1% from the total lipids in the patients with diabetes and obesity. Reverse alterations were established for the fraction of total phospholipids. Pronounced increase of the coefficient triglycerides/total phospholipids was established in case of diabetes and obesity.

Biopsy, Needle↗
PubMed1984

[Inhibitory effect of oil emulsions on the oocyst infectiveness of Eimeria tenella].

Comparative studies were carried out on the inhibitory effect of some oleoemulsions on the acute course of an experimental coccidial infection caused by Eimeria tenella. Such effect was demonstrated with the oral application of sporulated oocysts both with the complete and incomplete Freund's adjuvant and with oleum ricini and oleum helianthi in combination. The results of histopathologic investigations showed that the two types of Freund's adjuvant inhibited the rapid and joint excysting of a large number of oocysts. Inhibited was the invasion of sporozoits in the epithelial cells of the mucous membrane and thus the acute course of the coccidial infection caused by Eimeria tenella.

Animals↗
PubMed1981

[Clinical symptoms and the laparoscopic picture in chronic perihepatitis].

The author studied the clinical symptomatics of chronic perihepatitis, the diagnosis made laparoscopically in 163 patients with liver diseases. Ninety seven of them had pain and the sense of heaviness in the upper region of abdomen. The cause for those complaints in 33 patients (34,02%) was the chronic perihepatitis. In another 29 patients it was admitted a possible cause for the complaints. Therefore in 52 patients (53,61%), the complaints in the upper region of abdomen were due, most likely, to chronic perihepatitis. For the first time in literature, a systematic study on the clinical symptomatics of chronic perihepatitis is reported, an attempt made to explain the mechanism, causing its manifestation. According to the studies, besides Perihepatitis diffusa and Perihepatitis adhaesiva, Perihepatitis marginalis could also be the cause for complaints.

Aged↗
PubMed1980

[Gonococcal perihepatitis (Fitz-Hugh--Curtis syndrome)].

The author reviews the literature data concerning etiology pathogenesis, clinical picture, diagnosis, differential diagnosis and treatment of gonococcal perihepatitis or the so called syndrome of Fitz-Hugh--Curtis. A female patient is described with gonococcal perihepatitis, the diagnosis being retrospectively made by the author on the base of laparoscopy findings and clinical data. Perihepatal adhesions reminding "violin strings" as well as chronic salpingitis were established at laparoscopy 3 years after the acute gonoccal perihepatitis. At the second laparoscopy, 8 years later, the findings were the same. In that case -- two characteristics are present, not described in literature so far: 1. Periodic pain under the right hypochondriac region for 11 years, manifested immediately prior to or during the menstrual cycle. 2. The presence of chronic circumscribed peritonitis on the abdominal wall, proceeding from the right half of the true pelvis, irradiating upwards to the right liver lobe. The author thinks that those two characteristics are not isolated but on the contrary--they are mutually conditioned.

Adult↗
PubMed1979

[Laparoscopic picture and a working laparoscopic classification of chronic perihepatitis].

The author established chronic perihepatitis, via laparoscopy, in 61.6 percent of the investigated 350 patients in the course of 12 years. Describing the most characteristic mascoscopic varieties of chronic perihepatitis, the author groups them in seven separate form: I. Perihepatitis diffusa, corresponding to Zuckergussleber of Curschmann. II. Perihepatitis adhesiva and III. Perihepatitis circumscripta. The latter, on its part is subdivided to 5 separate forms of chronic perihepatitis: 1. Perihepatitis arachnoidealis, 2. Perihepatitis marginalis, 3. Perihepatitis areata et striata, 4. Perihepatitis miliaris disseminata, 5. Perihepatitis paravesicalis. That working laparoscopic classification contributes to the precise diagnostics and to the clinical interpretation of the separate forms of chronic perihepatitis. With the aid of lapraoscope the author performed a partial decapsulation of diffuse perihepatitis in 12 patients, without complications observed. Diffuse perihepatitis is, for the first time, described in patients with chronic hepatitis, in a patient with multiple liver abscesses and in one female-patient with peritoneal carcinosis and hemorrhagic ascites.

Biopsy, Needle↗
PubMed1976

[Therapeutic effect in 3 cases of hepatic coma in viral hepatitis].

The author reports his observation on three cases of coma hepaticum in viral hepatitis treated at the Internal Diseases Ward, Military Hospital, in the town of Asmara, Ethiopia. Parallelly with the usual hepatoprotective drugs and antibiotics, corticosteroids were administered as well as the preparation Reducdyn, containing homocysteine and cysteine-carriers of sulphhydryl groups. Complete restoration to health was achieved in two of the patients after three days in grave coma. The third patient was aroused from the comatose state for six hours but later had a lethal end on the eighth day post coma onset. According to the author, the combination of that preparation with corticosteroids is pathogenetically grounded and enables the administration of the latter in lower and safe doses. The author stresses upon the importance of early therapy in coma hepaticum.

Adult↗
PubMed1975

[Study of immunity in coccidiosis in chickens experimentally infected with Marek's disease].

The immunity was studied against coccidiosis in birds that had preliminary been infected with Marek's disease. Results showed that birds infected with Marek's disease are unable to build up stable immunity against an oocyst infection of Eimeria tenella. The rate of mortality due to Marek's disease in birds infected with the virus of Marek's disease and additionally infected with oocysts of E. tenella was higher as compared with that in birds that were infected only with the virus of Marek's disease.

Animals↗
PubMed1975

[Study of the immunogenic capacity of the oocytes of E. tenella following irradiation with gamma rays].

Studied was the immunizing capacity of Eimeria tenella oocysts, treated with gamma rays at the rate of 6000 R, in 10- and 20-day-old chickens. The oocysts sporulated after treatment. Applied at the rate of 50,000 R they showed lower virulence and were capable of inducing resistance to reinfection with nonirradiated oocysts at rates that were three times as much. Following reinfection some birds manifested subclinical coccidiosis but survived. This showed that the immunization with oocysts that had been irradiated with 6,000 R had its peculiar aspects.

Animals↗