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Biomedical subjects

A Inui

Publications and source records attributed to A Inui.

At least 55 records · Page 3Linked to original sources
PubMed2000

Long-term outcome of chronic hepatitis B in adolescents or young adults in follow-up from childhood.

BACKGROUND: It has not yet been defined whether children with chronic hepatitis B are likely to develop severe liver disease in the future. The purpose of this study was to evaluate the evolution of chronic hepatitis B acquired in childhood. METHOD: Fifty-two children in the age range of 0 to 15 years who were positive for hepatitis B surface antigen and hepatitis B e antigen in serum for at least 6 months were enrolled in this study. In the majority of the 52 children, hepatitis B virus infection was acquired by perinatal transmission. All 52 showed abnormal liver function test findings for more than 6 months before enrollment, and the subjects were followed up longitudinally for 3 to 22 years (mean, 11 years). They are now more than 15 years of age (15-27 years old). RESULTS: During the follow-up period, 26 (50%) children had spontaneous seroconversion to anti-hepatitis B e. Serum levels of alanine aminotransferase normalized in these 26 children. In one child of these children, hepatocellular carcinoma developed at the age of 21 years, 16 years after seroconversion, although his liver function profiles remained normal. The other 26 children remained hepatitis B e antigen positive, most with unchanged biochemical features. Sixteen (62%) children among these 26 children were treated with interferon-alpha. Eleven (69%) children had seroconversion to anti-hepatitis B e within the first year after the cessation of therapy. Hepatocellular carcinoma developed in 1 of these 11 children at the age of 16 years, 6 years after interferon therapy. Thus, hepatocellular carcinoma developed in two children in an anti-hepatitis B e positive phase. CONCLUSION: All children carrying hepatitis B surface antigen should be observed carefully to monitor the possible development of hepatocellular carcinoma, especially in the antihepatitis B e-positive phase after spontaneous seroconversion or even after interferon treatment.

Adolescent↗
PubMed2000

Neuropeptide Y induces fasted pattern of duodenal motility via Y(2) receptors in conscious fed rats.

Neuropeptide Y (NPY), a 36-amino acid peptide abundantly expressed in the brain, has been implicated in the regulation of feeding and visceral functions. The present study was designed to investigate whether or not NPY specifically regulates duodenal motility. The manometric method was used to measure duodenal motility in conscious, freely moving rats. The rat duodenum showed phasic contractions mimicking the migrating motor complex in the fasted state that were replaced by irregular contractions after the ingestion of food. NPY powerfully affected the contractile activity after intracerebroventricular (i.c.v.) administration, changing fed (postprandial) patterns into phasic contractions characterized as fasted (interdigestive) patterns. This effect was mediated via receptors with pharmacological profiles similar to rat Y(2) and Y(4) receptors, although neither Y(1) nor Y(5) agonists had any effects on motility despite potent feeding-stimulatory effects. Immunoneutralization with anti-NPY antiserum administered i.c.v. abolished fasted patterns and induced fed-like motor activities. An i.c.v. dose of peptide YY produced a different effect from NPY, with increase in the motor activities of both fed and fasted patterns. These results indicate that fasted and fed motor activities are regulated processes and that NPY induces fasted activity through Y(2), and possibly Y(4), receptors, which may represent an integrated mechanism linked to the onset of feeding behavior.

Animals↗
PubMed2000

Transgenic approach to the study of body weight regulation.

Energy homeostasis is accomplished through a highly integrated and redundant neurohumoral system. Recently, novel molecular mediators and regulatory pathways for feeding and body weight regulation have been identified in the brain and the periphery. Because of the multitude and complexity of disturbances in energy intake, expenditure, and partitioning that are associated with obesity, it has been difficult to determine which abnormalities are causative versus less important phenomena that are consequences of the altered neuroendocrine and metabolic milieu. Transgenic technology has provided new opportunities to modify the complex body weight-regulating system and to assess the relative importance of the individual components. Observations of mutant mice have shed new light on the understanding of energy homeostasis equation. Once created, transgenic animal models may be useful in assessing the efficacy or determining the mode of action of potential new therapeutic agents. However, the interpretation of targeted mutation is sometimes not straightforward in unraveling the physiology because of the redundancy and compensation of the regulatory machinery, as well as the inherent problems of manipulation of the gene. Modifying the synthesis of a particular gene at all sites and developmental stages may be a relatively crude way of investigating its functions. Advanced gene-targeting strategies aimed at specific alterations (on and off) of a gene product at desired tissues and times could lead to a better understanding of the system.

Animals↗
PubMed1999

Cancer anorexia-cachexia syndrome: are neuropeptides the key?

Progressive wasting is common in many types of cancer and is one of the most important factors leading to early death in cancer patients. Weight loss is a potent stimulus to food intake in normal humans and animals. The persistence of anorexia in cancer patients, therefore, implies a failure of this adaptive feeding response, although the weight loss in the patients differs from that found in simple starvation. Tremendous progress has been made in the last 5 years with regard to the regulation of feeding and body weight. It has been demonstrated that leptin, a hormone secreted by adipose tissue, is an integral component of the homeostatic loop of body weight regulation. Leptin acts to control food intake and energy expenditure via neuropeptidergic effector molecules within the hypothalamus. Complex interactions among the nervous, endocrine, and immune systems affect the loop and induce behavioral and metabolic responses. A number of cytokines, including tumor necrosis factor-alpha, interleukins 1 and 6, IFN-gamma, leukemia inhibitory factor, and ciliary neurotrophic factor have been proposed as mediators of the cachectic process. Cytokines may play a pivotal role in long-term inhibition of feeding by mimicking the hypothalamic effect of excessive negative feedback signaling from leptin. This could be done by persistent stimulation of anorexigenic neuropeptides such as corticotropin-releasing factor, as well as by inhibition of the neuropeptide Y orexigenic network that consists of opioid peptides and galanin, in addition to the newly identified melanin-concentrating hormone, orexin, and agouti-related peptide. Information is being gathered, although it is still insufficient, on such abnormalities in the hypothalamic neuropeptide circuitry in tumor-bearing animals that coincide with the development of anorexia and cachexia. Characterization of the feeding-associated gene products have revealed new biochemical pathways and molecular targets for pharmacological intervention that will likely lead to new treatments. Although therapeutic intervention using neuropeptide agonists/antagonists is now directed at obesity treatment, it may also have an effect on treating cancer anorexia-cachexia, especially when combined with other agents that have effects on muscle and protein breakdown.

Animals↗
PubMed1999

Thioperamide, a histamine H3 receptor antagonist, powerfully suppresses peptide YY-induced food intake in rats.

BACKGROUND: Whether or not peptide YY (PYY)-induced hyperphagia is modified by the histaminergic system in the brain is not yet known. METHODS: We investigated the effect on feeding of intracerebroventricular (ICV) administration of a specific histamine H3 receptor antagonist prior to ICV administration of PYY in rats. RESULTS: PYY (1, 3, and 10 micrograms/10 microL) strongly induced feeding behavior in a dose-dependent manner in sated rats. The 4-hour food intake induced by 3 micrograms/10 microL of PYY was equal to that induced by a 16-hour fast. The ICV administration of thioperamide (40.8, 122.4, and 408.5 micrograms/10 microL) did not suppress the 4-hour food intake induced by 16-hour fasting; however, thioperamide produced dose-dependent and strong inhibition of hyperphagia induced by a 3-microgram dose of PYY. CONCLUSIONS: These results suggest that the effect of PYY on appetite is different than that induced by fasting and may involve a histaminergic mechanism.

Analysis of Variance↗
PubMed1999

GBV-C/HGV infection in children with chronic hepatitis C.

The role of GB virus-C/hepatitis G virus (GBV-C/HGV), a recently identified member of the Flaviviridae family, in children with liver disease is not well understood. The aims of this study were to evaluate the prevalence of GBV-C/HGV and to clarify its pathogenic role in young patients with chronic hepatitis C. Sixty-four Japanese children and adolescents with chronic hepatitis C virus (HCV) infection, with a mean age of 9.8 years, were evaluated retrospectively. Twenty-one (32.8%) of the 64 patients were positive for serum GBV-C/HGV RNA. Only 1 (1.6%) of the 64 patients was positive for antibody against the envelope protein E2 of GBV-C/HGV (anti-E2) and GBV-C/HGV. None of them was positive for anti-E2 alone. There was no significant difference in clinical, virological, or histological characteristics between GBV-C/HGV-positive and GBV-C/HGV-negative patients, except for underlying malignant disease. There was no evidence that GBV-C/HGV might affect the response of HCV to interferon therapy in young patients with chronic hepatitis C. The prevalence of GBV-C/HGV infection in young patients with chronic hepatitis C is similar to that in adult patients with chronic hepatitis C, but E2-seroconversion is observed infrequently. Underlying malignant disease is a risk factor for GBV-C/HGV viremia. GBV-C/HGV does not seem to affect the clinical course of young patients with chronic hepatitis C.

Adolescent↗
PubMed1999

Generalized peritonitis with pneumoperitoneum caused by the spontaneous perforation of pyometra without malignancy: report of a case.

Spontaneous perforation is a very rare complication of pyometra. We report herein the case of an 88-year-old woman who presented with muscular rigidity and free air on abdominal X-ray films. Perforation of the gastrointestinal tract was diagnosed preoperatively, and an emergency laparotomy was performed. A total hysterectomy with bilateral salpingo-oophorectomy was carried out under the diagnosis of generalized peritonitis caused by the spontaneous perforation of pyometra. The culture of purulent fluid from the abdominal cavity showed only Escherichia coli, with no anaerobic bacteria. Histological examination revealed pyometra with necrosis of the endometrium and no evidence of malignancy. The patient was discharged on postoperative day 68 without any major complications. Pyometra is an unusual cause of peritonitis, but it must be considered as a possible diagnosis in elderly women presenting with an acute abdomen. Following this case report, we discuss the problems associated with establishing a correct preoperative diagnosis of generalized peritonitis caused by the spontaneous perforation of pyometra.

Aged↗
PubMed1999

Decreased food intake and body weight in pancreatic polypeptide-overexpressing mice.

BACKGROUND & AIMS: Pancreatic polypeptide (PP) is a 36-amino acid hormone produced by F cells within the pancreatic islets and the exocrine pancreas. The definitive function of PP in mammalian physiology remains to be determined. This study examined the effects of chronic overexpression of PP through the development of PP transgenic mice. METHODS: PP transgenic mice were created by using mouse PP complementary DNA under the control of the cytomegalovirus immediate early enhancer-chicken beta-actin hybrid promoter (pCAGGS expression vector). RESULTS: A unique line of transgenic mice was created that overexpresses PP in the pancreatic islets with low levels of expression in other tissues including the brain. Plasma PP concentrations were more than 20 times higher than those of control littermates. However, PP overproduction led to postnatal lethality in half of the pups because of markedly decreased milk intake. The remaining PP transgenic mice gained less weight with specifically reduced food intake and fat mass compared with controls, a result that was more evident in male than in female mice. The transgenic mice exhibited a reduced rate of gastric emptying of a solid meal but had normal oxygen consumption and fasting leptin levels. Immunoneutralization with anti-PP antiserum reversed the phenotypic changes of transgenic animals. CONCLUSIONS: PP could be involved in feeding and body weight regulation partly through regulation of gastric emptying.

Animals↗
PubMed1999

Urocortin reduces food intake and gastric emptying in lean and ob/ob obese mice.

BACKGROUND & AIMS: Gastric emptying plays an important role in regulating food intake. This study was designed to investigate whether intraperitoneally injected urocortin reduces gastric emptying, feeding, and body weight in lean and ob/ob obese mice. METHODS: Food intake and body weight were measured after intraperitoneal injections of one of the following: urocortin, deamidated form of urocortin (urocortin OH), corticotropin-releasing factor (CRF), CRF6-33, cholecystokinin octapeptide (CCK-8), and leptin in 16-hour food-deprived animals. Gastric emptying was assessed 2, 4, or 8 hours after intraperitoneal injection. Repeated injections of urocortin were continued for 5 days in ob/ob mice. RESULTS: Urocortin (0.003-3 nmol) dose-dependently and potently decreased food intake and body weight gain in lean mice. The ranking order of potency was urocortin > urocortin OH >/= CRF > CCK-8 > CRF6-33 > leptin. Gastric emptying was also potently reduced by urocortin with a similar ranking order of potency of urocortin > CRF > urocortin OH > CCK-8. Simultaneous administration of urocortin and CRF receptor antagonist, alpha-helical CRF9-41, blocked the effects of urocortin. Urocortin reduced food intake and body weight gain, as well as the rate of gastric emptying, in ob/ob mice, which was significantly faster than that of lean mice. Five daily injections of urocortin significantly lowered body weight and improved glycemic control in ob/ob mice. CONCLUSIONS: The urocortin-induced decrease in food intake and body weight in lean and ob/ob mice is closely related to gastric emptying and opens new possibilities for the treatment of obesity.

Animals↗
PubMed1999

Feeding and body-weight regulation by hypothalamic neuropeptides--mediation of the actions of leptin.

Neuropeptides are essential for the regulation of appetite and body weight within the hypothalamus. The understanding of the neuropeptide regulation of energy homeostasis has been greatly advanced by the recent discovery of leptin, the protein product of the obese gene (ob). Significant new insights into the relationship between peripheral adiposity signals and their impact on the hypothalamic neuropeptide signaling circuitry have provided some crucial missing links in the negative-feedback regulation of appetite and body weight. The neuropeptide Y orexigenic network is a final common pathway for this signaling cascade and, along with feeding-inhibitory neuropeptides such as melanocortin, corticotropin-releasing factor and glucagon-like peptide 1, it is a major target through which leptin exerts a regulatory tonic restraint on body adiposity.

Animals↗
PubMed1999

Mouse pancreatic polypeptide modulates food intake, while not influencing anxiety in mice.

This study was designed to investigate the effects of synthetic mouse pancreatic polypeptide (mPP) on feeding and anxiety in mice. The intracerebroventricular (i.c.v.) injection of mPP (0.003-3 nmol) dose-dependently increased food intake. A significant increase was observed 20 min after i.c.v. injection and continued for 4 h. The intraperitoneal (i.p.) injection of mPP (0.03-30 nmol) dose-dependently decreased food intake. A significant decrease was observed 20 min after i.p. injection and continued for 4 h. In the elevated plus maze test, the i.c.v. injection of mPP (0.003-3 nmol) did not affect anxiety behavior. These results suggest that mPP modulates food intake and the Y4 receptor in the brain may contribute to the regulation of feeding, whereas appearing not to influence anxiety in mice.

Animals↗
PubMed1999

Neuropeptide Y: a key molecule in anorexia and cachexia in wasting disorders?

Anorexia and body weight loss are characteristic of many diseases, including cancer and AIDS. Recent studies indicate that inflammatory cytokines, such as interleukin 1, the interleukin 6 subfamily and tumor necrosis factor, induce anorexia and cachexia by inhibiting the normal adaptive feeding response to energy deficits. Here, I discuss the evidence for and against a central role for neuropeptide Y and leptin in anorexia and cachexia.

Animals↗
PubMed1999

Severe late acute allograft rejection in a child after living-related auxiliary partial orthotopic liver transplantation for ornithine transcarbamylase deficiency.

Auxiliary liver transplantation (ALT) is known to correct liver-based metabolic disorders. However, it remains unclear whether the presence of a native liver influences the long-term prognosis of ALT for metabolic diseases. We reported on a 4-yr-old girl who had undergone living-related auxiliary partial orthotopic liver transplantation (APOLT) for ornithine transcarbamylase deficiency and experienced severe late acute rejection 18 months after liver transplantation, during weaning of immunosuppressive agents. Results of histological analysis of the graft indicated very severe acute rejection (rejection activity index, 9/9), and computed tomography revealed graft liver atrophy. These observations suggest the possibility that severe rejection might occur in APOLT, especially during weaning of immunosuppression.

Acute Disease↗
PubMed1999

Hepatitis B precore mutant in children with chronic hepatitis B virus infection.

BACKGROUND: In adults, hepatitis B virus (HBV) with a G to A point mutation at nucleotide 83 in the precore region (mutant HBV 83), is commonly found in HB e antibody positive HBV carriers. It has been reported that this mutant is not able to produce HB e antigen. The exact prevalence of mutant HBV 83 in patients with chronic HBV infection is not fully understood, especially in children. METHODS: To investigate the role of mutant HBV 83 in children with chronic HBV infection, sera were tested for the presence of mutant HBV 83 using a mutation site-specific assay. RESULTS: Mutant HBV 83 was detected in 15 of 22 children (68%). Seven children were followed longitudinally, of which three were asymptomatic carriers and the other four had chronic hepatitis B on entry. There was no clear relationship between the disease activity and the presence of mutant HBV 83. CONCLUSIONS: It was concluded that mutant HBV 83 is commonly present in children with chronic HBV infection and this mutant is not necessarily associated with activation of hepatitis.

Adolescent↗
PubMed1999

Intracerebroventricularly administered corticotropin-releasing factor inhibits food intake and produces anxiety-like behaviour at very low doses in mice.

AIM: Previous studies have demonstrated that corticotropin-releasing factor (CRF) produces behavioural, physiological and immunological responses similar to those induced by stress. However, these findings have been validated largely in laboratory rats. METHODS: We examined the effects of intracerebroventricular (i.c.v.) administration of CRF on anxiety and food intake in mice. Using the elevated-plus maze, we measured anxiety levels after i.c.v. CRF in mice. We also measured food intake for 2 h after i.c.v. CRF. RESULTS: CRF increased the normal preference for the closed arms of the maze at a very low dose of 3 pmol, indicating an anxiogenic effect. CRF powerfully suppressed food intake at the doses of 3-300 pmol for over 2 h. CONCLUSION: Our results demonstrate that i.c.v. CRF evokes anxiogenic behaviour and suppresses feeding with the same dose-response relationships in mice. CRF may thus play a role in integrating the overall responses to stress through co-ordinated actions in the brain of this species.

Animals↗