Hepatic leptin signalling and subdiaphragmatic vagal efferents are not required for leptin-induced increases of plasma IGF binding protein-2 (IGFBP-2) in ob/ob mice.

AIMS/HYPOTHESIS: The fat-derived hormone leptin plays a crucial role in the maintenance of normal body weight and energy expenditure as well as in glucose homeostasis. Recently, it was reported that the liver-derived protein, insulin-like growth factor binding protein-2 (IGFBP-2), is responsible for at least some of the glucose-normalising effects of leptin. However, the exact mechanism by which leptin upregulates IGFBP-2 production is unknown. Since it is believed that circulating IGFBP-2 is predominantly derived from the liver and leptin has been shown to have both direct and indirect actions on the liver, we hypothesised that leptin signalling in hepatocytes or via brain-liver vagal efferents may mediate leptin control of IGFBP-2 production. METHODS: To address our hypothesis, we assessed leptin action on glucose homeostasis and plasma IGFBP-2 levels in both leptin-deficient ob/ob mice with a liver-specific loss of leptin signalling and ob/ob mice with a subdiaphragmatic vagotomy. We also examined whether restoring hepatic leptin signalling in leptin receptor-deficient db/db mice could increase plasma IGFBP-2 levels. RESULTS: Continuous leptin administration increased plasma IGFBP-2 levels in a dose-dependent manner, in association with reduced plasma glucose and insulin levels. Interestingly, leptin was still able to increase plasma IGFBP-2 levels and improve glucose homeostasis in both ob/ob mouse models to the same extent as their littermate controls. Further, restoration of hepatic leptin signalling in db/db mice did not increase either hepatic or plasma IGFBP-2 levels. CONCLUSIONS/INTERPRETATION: Taken together, these data indicate that hepatic leptin signalling and subdiaphragmatic vagal inputs are not required for leptin upregulation of plasma IGFBP-2 nor blood glucose lowering in ob/ob mice.

RNA polymerase II and III transcription factors can stimulate DNA replication by modifying origin chromatin structures.

Many transcription factors are multifunctional and also influence DNA replication. So far, their mechanism of action has remained elusive. Here we show that a DNA-binding protein could rely on the same biochemical activity that activates transcription to stimulate replication from the yeast chromosomal ARS1 origin. Unexpectedly, the ability to stimulate replication from this origin was not restricted to polymerase II transcription factors, but was a property shared by polymerase III factors. Furthermore, activation of replication did not depend on the process of transcription, but rather on the ability of DNA-binding transcription factors to remodel chromatin. The natural ARS1 activator Abf1 and the other transcription factors that stimulated replication remodeled chromatin in a very similar manner. Moreover, the presence of a histone H3 mutant that was previously shown to generally increase transcription also facilitated replication from ARS1 and partially compensated for the absence of a transcription factor. We propose that multifunctional transcription factors work by influencing the chromatin architecture at replication origins so as to generate a structure that is favorable to the initiation of replication.

Experimental and clinical study in the treatment of sigmoid volvulus.

The aim of the study was to introduce an alternative surgical procedure for the treatment of primary volvuius of the sigmoid colon. Sigmoid colon plication was performed in 42 dogs, and afterwards in six patients. The procedure consists of systematic plaiting the sigmoid colon wall with interrupted serosubmucosal 3/0 Vicryl sutures along the whole circumference, except on the mesenteric border. Five parallel circular folds were done in dogs, and 20-30 folds in patients, with appropriate bowel length reduction. In the experimental study, dogs were randomly divided into three experimental and one control group of 14 animals each. The group 1 dogs were sacrificed on day 8, group 2 dogs on day 15, and group 3 and control group dogs on day 30 postoperatively. On exploration, sigmold colon adhesions were found in 6 (14.3%) animals. Intestinal wall and lumen were normal. In the clinical study, six patients with sigmoid volvulus were operated on within 6-8 hours of admission. A viable colon was a prerequisite for the sigmoid plication procedure. The operating time was 60-90 minutes. Recovery was uneventful, with average hospitalization 11 (range 8-15) days. No volvulus recurrence was recorded during the three-year follow-up. Based on our experimental and clinical data, we believe that the plication procedure could be appropriate treatment in some selected patients with volvulus of the sigmold colon.

Flail chest stabilization with palacos prosthesis.

The approach and management of patients with post-traumatic flail chest continue to be a controversial issue. A method of surgical stabilization of flail chest using palacos, a cement-like material is described. A ready-made prosthesis is placed on the external side of the ribs vertically bridging the flailed chest segment, and fixed to the first upper and first lower intact rib as well as to the mobile segments of the affected ribs. Surgical fixation was carried out in 56 patients. The results proved the method to be a simple and effective procedure.

Effects of prenatal ethanol exposure on hypothalamic-pituitary-adrenal regulation after adrenalectomy and corticosterone replacement.

BACKGROUND: Previous studies have demonstrated that rats prenatally exposed to ethanol (E) exhibit hypothalamic-pituitary-adrenal (HPA) hyperresponsiveness, demonstrated by increased and/or prolonged elevations of adrenocorticotropin (ACTH) and/or corticosterone (CORT) after stress. This study investigated possible mechanisms of HPA hyperresponsiveness in E rats by manipulating CORT feedback regulation of HPA activity via adrenalectomy (ADX) with or without CORT replacement. METHODS: Male Sprague-Dawley rat offspring from prenatal E, pair-fed (PF) and ad libitum-fed control (C) groups were tested at 90 to 120 days of age. Rats were either sham-operated or underwent ADX, with or without CORT replacement. CORT (25 microg/ml) was replaced via the drinking water to achieve basal plasma CORT levels and maintain a phasic CORT signal. Seven days after surgery, animals were decapitated at the diurnal peak either under basal conditions or after a 15-min restraint stress, and trunk blood was collected. RESULTS: After ADX, loss of the CORT feedback signal resulted in increased plasma ACTH in all groups compared with those in sham animals. In addition, under basal conditions, ADX E rats had significantly greater plasma ACTH levels than both PF and C rats. However, no differences were seen in ADX rats after stress. CORT replacement after ADX was partially effective in normalizing ACTH levels under both basal and stress conditions, with no differences among E, PF, and C animals. CONCLUSIONS: These results suggest that E males may exhibit enhanced stimulatory inputs to the hypothalamus, increased pituitary sensitivity to secretagogues, or both, which may be revealed after ADX. In contrast, E animals seem similar to controls in their ability to use an exogenous CORT signal to regulate HPA activity.

Patch reconstruction of hemidiaphragm agenesis by the polypropylene mesh prosthesis.

We present a case of a middle-aged woman with right hemidiaphragm agenesis, which became evident after a blunt injury. Ultrasound, X-ray, and computed tomography confirmed the diagnosis, and the diaphragmatic congenital defect was closed by insertion of a polypropylene mesh prosthesis.

Conservation of glutamine-rich transactivation function between yeast and humans.

Several eukaryotic transcription factors such as Sp1 or Oct1 contain glutamine-rich domains that mediate transcriptional activation. In human cells, promoter-proximally bound glutamine-rich activation domains activate transcription poorly in the absence of acidic type activators bound at distal enhancers, but synergistically stimulate transcription with these remote activators. Glutamine-rich activation domains were previously reported to also function in the fission yeast Schizosaccharomyces pombe but not in the budding yeast Saccharomyces cerevisiae, suggesting that budding yeast lacks this pathway of transcriptional activation. The strong interaction of an Sp1 glutamine-rich domain with the general transcription factor TAF(II)110 (TAF(II)130), and the absence of any obvious TAF(II)110 homologue in the budding yeast genome, seemed to confirm this notion. We reinvestigated the phenomenon by reconstituting in the budding yeast an enhancer-promoter architecture that is prevalent in higher eukaryotes but less common in yeast. Under these conditions, we observed that glutamine-rich activation domains derived from both mammalian and yeast transcription factors activated only poorly on their own but strongly synergized with acidic activators bound at the remote enhancer position. The level of activation by the glutamine-rich activation domains of Sp1 and Oct1 in combination with a remote enhancer was similar in yeast and human cells. We also found that mutations in a glutamine-rich domain had similar phenotypes in budding yeast and human cells. Our results show that glutamine-rich activation domains behave very similarly in yeast and mammals and that their activity in budding yeast does not depend on the presence of a TAF(II)110 homologue.

Glucocorticoid fast feedback is not altered in rats prenatally exposed to ethanol.

Animals exposed in utero to ethanol exhibit hormonal hyperresponsiveness to stressors in adulthood. One possible mechanism for this hyperresponsiveness is a deficit in negative feedback regulation of the hypothalamic-pituitary-adrenal axis. The present study tested the hypothesis that a deficit in the fast feedback time domain may play a role in the hormonal hyperresponsiveness in ethanol-exposed rats. Sprague-Dawley offspring from prenatal ethanol (E), pair-fed (PF), and ad lib-fed control (C) groups were tested in two experiments. Experiment 1 used a swim stress paradigm and tested animals at the trough of the corticosterone (CORT) circadian rhythm. Experiment 2 used ether stress and tested animals at the peak of the circadian rhythm. Animals were injected subcutaneously with CORT or saline and were immediately subjected to either a 5-min swim stress or a 1-min ether stress. Half the animals were terminated immediately after stress (5-min postinjection), and the rest were terminated 25 min later. Plasma levels of CORT and ACTH were assayed to determine whether E animals differed from control animals in showing a CORT-induced blunting of the ACTH response to the stressor, indicating alterations in fast feedback regulation. Injection of CORT significantly blunted the ACTH response to swim stress (experiment 1) in E, PF, and C females and males, compared with their saline-injected counterparts. There were no significant differences among groups. Similarly, CORT-injected males in E, PF, and C groups all exhibited a significantly blunted ACTH response to ether stress (experiment 2). CORT-injected C females also exhibited a significantly blunted ACTH response to ether stress, whereas E females showed an obvious CORT decrease that approached significance. However, PF females showed a clear deficit in fast feedback regulation. Together, these data suggest that: (1) CORT injection can serve as a fast feedback signal that can blunt the ACTH response to a stressor; and (2) prenatal ethanol exposure does not produce a deficit in hypothalamic-pituitary-adrenal feedback regulation in the fast feedback time domain.

Age-related decline of perforin expression in human cytotoxic T lymphocytes and natural killer cells.

In this study a flow cytometric technique for detecting cytoplasmic perforin (P) has been used to quantify age-related changes in perforin expression in human peripheral blood lymphocytes (PBL). Proportions of P+ lymphocytes increased after birth, but declined rapidly after the age of 70 years. This was true for both T cells and CD16(+) and CD56(+) natural killer (NK) cells. Children showed in addition to high levels of perforin positive CD8(+) cells a much higher proportion of CD4(+)P+ cells than the other age groups. In elderly individuals there was also a highly significant reduction in mean levels of perforin per cell as compared with all other groups (P < .05 to .001). Adult women had consistently higher mean levels of perforin per cell than adult men for all P+ cell phenotypes. Functional tests clearly showed the deficiency in early spontaneous cytotoxic potential of PBL from elderly persons due to relative P deficiency, which can be corrected by stimulation of cytolytic cells with target cells and interleukin-2 (IL-2). The deficiency in cytolytic activity on the contact with target cells may have implications for antiviral and antitumor immunity in elderly persons.

The hormonal effects of alcohol use on the mother and fetus.

During pregnancy, the hormonal systems of the mother and fetus are intricately interconnected to ensure normal fetal development. Accordingly, maternal alcohol consumption during pregnancy can interfere with fetal development, not only directly, through adverse effects exerted by alcohol that crosses the placenta and enters the fetal bloodstream, but also indirectly, by disturbing the functions and interactions of maternal and fetal hormones. In both the mother and the fetus, alcohol exposure can impair the functioning of the hypothalamic-pituitary-adrenal axis, which regulates the body's response to stress; the hypothalamic-pituitary-gonadal axis, which controls reproductive functions; and the hypothalamic-pituitary-thyroid axis, which regulates the metabolism of almost all tissues. In addition, alcohol can interfere with the activities of growth hormone and insulin-like growth factors, which promote body growth and activity. Some of the effects of maternal alcohol consumption on fetal hormone systems may contribute to the adverse effects observed in children with fetal alcohol syndrome and related disorders.

The STT3 protein is a component of the yeast oligosaccharyltransferase complex.

N-linked protein glycosylation is an essential process in eukaryotic cells. In the central reaction, the oligosaccharyltransferase (OTase) catalyzes the transfer of the oligosaccharide Glc3Man9GlcNac2 from dolicholpyrophosphate onto asparagine residues of nascent polypeptide chains in the lumen of the endoplasmic reticulum. The product of the essential gene STT3 is required for OTase activity in vivo, but is not present in highly purified OTase preparations. Using affinity purification of a tagged Stt3 protein, we now demonstrate that other components of the OTase complex, namely Ost1p, Wbp1p and Swp1p, specifically co-purify with the Stt3 protein. In addition, different conditional stt3 alleles can be suppressed by overexpression of either OST3 and OST4, which encode small components of the OTase complex. These genetic and biochemical data show that the highly conserved Stt3p is a component of the oligosaccharyltransferase complex.

[Pancreatic resection and hypothermic peritoneal irrigation in the treatment of patients with necrotizing pancreatitis]. / Pankreaticna resekcija i hipotermicna peritonealna irigacija u lijecenju bolesnika s nekrotizirajucim pankreatitisom.

Mortality of non-operated patients suffering from necrotizing pancreatitis is very high, while at those operated is considerably less but not satisfactory. Because of in 1976 we have managed our own modified treatment which includes surgical removal of all necrotic tissue followed by the hypothermic continuous peritoneal lavage-drainage procedure for evacuation of residual devitalized dead tissue and elimination biologically active substances. Using this curative method, we succeeded to reduce mortality rate to 26 percent.

[Hospital treatment of child-tourists at the Pula Medical Center 1983-1988]. / Bolnicki lijecena djeca-turisti u Puli od 1983. do 1988. godine.

During the 6-year period, 687 children-tourists, aged up to 12 years, were treated at the departments of the Medical Center of Pula; on average 114.5 (standard deviation +/- 17.79) children per year. There were 449 (65.4%) patients from different parts of Yugoslavia and 238 (24.6%) from abroad. Two hundred and fifty-four (37.9%) patients were treated at the Department of Paediatrics 231 (33.7%) at the Department of Surgery, 168 (24.4%) at the Department of Infectious Diseases, then 30 (4.4%) at the Department of Ear, Nose and Throat, 3 female patients (0.4%) at the Department of Gynecology and only one boy was treated at the Department of Ophthalmology. There were 22 (3.2%) newborns, 48 (7%) infants, 143 (20.8%) were one to three years old, then 130 (18.9%) were 4 to six years old and 344 (50.1%) older than 7 years. During the 6-year period, children-tourists accounted for 5.1% of the hospitalized children. 81.3% of the patients were treated during June, July and August, the peak being in July (39%). The most frequent diseases were from the group "infectious and parasitic diseases" (188 patients = 27.4%) and among them "diarrheal syndrome" in 82% of patients, then the group "injuries and poisons" (140 patients 20.4%) among which there were 57 (40.4%) superficial injuries, contusions and open wounds, then in 33 (23.5%) patients different fractures; in this group 10% of children were poisoned mostly by drugs (sedatives and tranquilizers) used by their parents.(ABSTRACT TRUNCATED AT 250 WORDS)