Cholecystokinin expression in the developing and regenerating pancreas and intestine

In developmental terms, the endocrine system of neither the gut nor the pancreatic islets has been characterized fully. Little is known about the involvement of cholecystokinin (CCK), a gut hormone, involved in regulating the secretion of pancreatic hormones, and pancreatic growth. Here, we tracked CCK-expressing cells in the intestines and pancreata of normal mice (BALB/c), Non Obese Diabetic (NOD) mice and interferon (IFN)-gamma transgenic mice, which exhibit pancreatic regeneration, during embryonic development, the postnatal period and adulthood. We also questioned whether IFN-gamma influences the expression of CCK. The results from embryonic day 16 showed that all three strains had CCK in the acinar region of pancreata, and specifically in alpha cells that also expressed glucagon. However, in adulthood only BALB/c and NOD mice continued this pattern. By contrast, in IFN-gamma transgenic mice, CCK expression was suppressed from birth to 3 months of age in the pancreata but not intestines. However, by 5 months of age, CCK expression appeared in the regenerating pancreatic ductal region of IFN-gamma transgenic mice. In the intestine, CCK expression persisted from fetus to adulthood and was not influenced by IFN-gamma. Intestinal cells expressing CCK did not co-express glucagon, suggesting that these cells are phenotypically distinct from CCK-expressing cells in the pancreatic islets, and the effect of IFN-gamma on CCK varies depending upon the cytokine's specific microenvironment.

[Spatial structure and pattern of Nilaparvata lugens population in large-scale]

Brown planthopper(BPH), Nilaparvata lugens, is a major pest of rice. Its spatial distribution of different generations in Guangdong Province was studied by using variograms. The results showed that this population distributed in a clump pattern in rice fields during the 1st rice season. 3 generations of this population had different spatial structures, with the clump range of 400 km, 200 km and 205 km respectively in the 1st rice season. The simulation distribution maps of BPH, which was interpolated by Ordinary Kriging, showed that the density of BPH populations in west Guangdong province were higher than that in the east. The effect of sampling size on the spatial structure of BPH was not significant.

[Application of molecular markers-assisted selection of wx genes in breeding the waxy wheat]

Chinese Spring and its null-tetrasomic lines were used to identify the specific bands of STS-marker and microsatellites (SSR) marker of wx genes. Twelve varieties and five waxy wheat lines were screened with these two markers, and the results are in agreement with those from Wx subunits SDS-PAGE. A F2 segregating population from cross Jiangsu Baihuomai x Kanto 107 was also detected by molecular markers, not only eight wx genotypes were developed while three genotypes did not exist in the nature, but also the first batch of waxy wheat lines were bred. The Jiangsu Bainuomai improvement population was screened, and six 7D momosomic plants with wx-D1b were obtained, which could provide materials for waxy wheat breeding. Application molecular markers of wx genes will improve the selection procedure for the waxy wheat and good noodle-quality wheat.

[Hostility behavior as risk factor of coronary heart disease]

OBJECTIVE

To explore the relationships between hostility, and the risks of coronary-prone behavior and the clusters of unhealthy behaviors in individuals with different levels of hostility.

METHODS

A cross-sectional study was carried out among 1 010 male employees from two factories in Beijing Capital Steel and Iron Company in 1997. Data on major risks of cardiovascular, other social-demographic factors and levels of hostility by Cook-Medley Scales were collected.

RESULTS

Body mass index, amounts of cigarette smoking and alcohol drinking were significantly increased (P < 0.01) with a characteristic of reduced social support from one's colleagues, when individual's level of hostility increased. In addition, less years of education, higher prevalence of other chronic diseases (P < 0.05) and clustering of various unhealthy behaviors were found related to the increase of individual's hostility. The odds ratio in the group with highest hostility was 2.37 times higher than in the lowest one, after confounding effects from age, blood pressure, education level, status of chronic disease and social support being adjusted. No significant differences on both systolic and diastolic blood pressures among groups with different levels of hostility were discovered.

CONCLUSION

The association between hostility, coronary-prone risk behavior and cluster of unhealthy behaviors suggested that hostility might increase the risk of coronary heart diseases through affecting individual's behavior.

Sterols and inhibitors of sterol transport modulate the degradation and secretion of macrophage ApoE: requirement for the C-terminal domain

Macrophage-derived apoE, produced in the vessel wall, may have important effects during atherogenesis. The production of apoE by macrophages can be regulated at a transcriptional level by cellular differentiation state, cytokines and sterol loading. In addition, there are post-transcriptional and post-translational loci for regulation. We have recently identified an intermediate density cell membrane fraction in which the degradation of apoE can be modulated by sterols. Suppressing degradation of apoE in this fraction by pre-incubating cells in sterols led to enhanced apoE secretion. In this report we demonstrate that the suppressive effect of sterols on the degradation of newly synthesized apoE in this fraction depends on the presence on its C-terminal domain, by studying a macrophage cell line transfected to express a mutant form of apoE in which amino acids beyond amino acid 202 were deleted. In addition, two modulators of cellular sterol transport, progesterone and U1866A, inhibited the degradation of full-length apoE. In contrast, incubation of cells in the acyl-CoA:cholesterol acyltransferase inhibitor S58035 did not influence apoE degradation. As would be predicted based on the results of degradation assays, U1866A, but not S58035, increased the secretion of apoE from a cell line transfected to constitutively express full-length apoE cDNA. The effect of U1866A on apoE degradation, like the effect of sterol, required the presence of the apoE C-terminal domain. Our results indicate that alteration of intracellular sterol homeostasis by pre-incubation in sterols or by drugs that modify the subcellular transport of sterol, modulates the susceptibility of apoE to degradation and that this modulation requires the presence of C-terminal lipid binding domains.

Outcome of an institutional sexual offender treatment program: a comparison between treated and matched untreated offenders

Data from a sexual offender treatment program operated by the Correctional Service of Canada at the Regional Psychiatric Center (Saskatoon) supported the conclusion that cognitive behavioral treatment can reduce sexual offense recidivism. The study compared 296 treated and 283 untreated offenders followed for a mean of 6 years after their release. An untreated comparison subject was located for each treated offender on three dimensions: (a) age at index offense, (b) date of index offense, and (c) prior criminal history. Data were analyzed using tests of proportion, survival analysis, and analysis of offender Criminal Career Profiles. Over a mean follow-up period of almost 6 years, convictions for new sexual offenses among treated offenders were 14.5% versus 33.2% for untreated offenders. During the follow-up period, 48% of treated offenders remained out of prison compared to 28.3% of untreated offenders. Time series comparisons of treated and comparison samples also showed that treated men reoffended at significantly lower rates after 10 years. A Criminal Career Profile (CCP) was constructed by taking the Age at First Conviction and plotting the offender's successive lengths of time free against time incarcerated. Pre- and posttreatment slopes of the CCP were lower for both groups posttreatment; however, the degree of change was significantly greater for the treated group, indicating a greater reduction in criminal activity among these offenders. Taken together, the results of all three analytic techniques supported the efficacy of appropriate correctional treatment for effective reduction of recidivism.

Expression of ErbB receptors during pancreatic islet development and regrowth

We have characterized expression of the ErbB receptor family and one of its ligands, heregulin, in an effort to identify molecules associated with pancreatic development and regeneration. In addition to studying expression during fetal pancreatic development, we have also studied expression during pancreatic regeneration in the interferon-gamma (IFNgamma)-transgenic mouse, which exhibits significant duct cell proliferation and new islet formation. These studies demonstrate significant expression of the ErbB2, ErbB3, and ErbB4 receptors, in addition to heregulin isoforms, in the developing murine fetal pancreas. We also report significant ductal expression of these proteins during IFNgamma-mediated pancreatic regeneration. This striking expression was absent in 1-week-old neonates, but was clearly visible in pups by 5 weeks of age. These data therefore indicate that ErbB receptor and ligand expression decline by birth in both the IFNbeta-transgenic and non-transgenic mice, and that expression resumes early in postnatal life in the IFNbeta-transgenic mice. The expression of ErbB receptor family members at sites of islet development and regrowth suggests that these molecules might be relevant to these processes.

[Cost-effectiveness analysis of Beijing Fangshan cardiovascular prevention program in 1992 - 1997]

OBJECTIVE

To determine whether a community-based cardiovascular disease (CVD) intervention program, undertaken over six years, was cost-effective.

METHODS

Based on Beijing Fangshan Cardiovascular Disease Comprehensive Prevention Program, the cost for intervention and expenditure saved from caring for CVD in the communities with intervention from 1992 to 1997 were calculated, and cost-effectiveness analysis was performed using disability-adjusted life years (DALYs) gained as an indicator of effectiveness.

RESULTS

The cost for one DALY gained reduced gradually from 1992 to 1997, with an average ratio of cost to effectiveness of four to one (4:1). It cost annually 1,586.00, 1,380.20, -2,350.80, -905.30, -1,495.60 and -1,766.70 RMB yuan for one life-year saved, from 1992 to 1997 respectively, in a gradually decreasing trend with the increase in length of intervention. After intervention for two years, ratio of cost to effectiveness has become negative since 1994, which meant a positive benefit from intervention. Sensitivity analysis showed that ratio of cost to effectiveness was little sensitive to the changes in discount rate, weight of age and increase in cost of hospitalization for stroke and coronary heart disease, which reflected its reliability.

CONCLUSION

Community-based comprehensive intervention for CVD in rural population is cost-effective.

Immunization levels among premature and low-birth-weight infants and risk factors for delayed up-to-date immunization status. Centers for Disease Control and Prevention Vaccine Safety Datalink Group

CONTEXT

Studies have noted that health care professionals may not conform to proper immunization schedules for premature and low-birth-weight infants in the United States. Little is known about the success of current efforts to immunize these high-risk infants.

OBJECTIVE

To describe current immunization practices for premature and low-birth-weight infants and ascertain risk factors for poor immunization status, using large population-based data sources.

DESIGN AND SETTING

Cohort and case-control analyses of immunization data tracked from March 1991 through March 1997 for 3 large health maintenance organizations (HMOs) participating in the Centers for Disease Control and Prevention's Vaccine Safety Datalink project.

PARTICIPANTS

A total of 11580 low-birth-weight and premature infants were enrolled from birth to age 2 months; 6832 of these were continuously enrolled from birth to age 24 months. At age 2 months, there were 173373 full-term, normal-birth-weight infants enrolled as controls; at age 24 months, there were 103 324.

MAIN OUTCOME MEASURES

Age-specific immunization status by prematurity and birth weight (<1500 g, 1500-2500 g, born at <38 weeks' gestation with birth weight of >2500 g, or full-term with normal birth weight) and patient characteristics associated with up-to-date status.

RESULTS

At each age, infants weighing less than 1500 g at birth had lower up-to-date immunization levels than other infants. At age 6 months, 52% to 65% of infants weighing less than 1500 g were up-to-date at each of the 3 HMOs compared with 69% to 73% of those weighing 1500 to 2500 g, 66% to 80% of premature infants weighing more than 2500 g, and 65% to 76% of full-term, normal-birth-weight infants. By age 24 months, 78% to 86% of infants weighing less than 1500 g were up-to-date, significantly less than heavier infants, who had levels of 84% to 89%. Well-child preventive care strongly predicted immunization status, while concomitant pulmonary disease did not.

CONCLUSIONS

Our data suggest that infants born prematurely are vaccinated at levels approaching that of the general population, but levels of vaccination for very low-birth-weight infants lag slightly behind.

Transgenic expression of epidermal growth factor and keratinocyte growth factor in beta-cells results in substantial morphological changes

The upregulation of a limited number of growth factors in our interferon-gamma transgenic model for regeneration within the pancreas lead us to propose that these factors are important during pancreatic regeneration. In this study, we have assessed the influence of two growth factors within the pancreas, epidermal growth factor (EGF) and keratinocyte growth factor (KGF), by ectopically expressing these proteins under the control of the human insulin promoter in transgenic mice. This beta-cell-targeted expression of either EGF or KGF resulted in significant morphological changes, including cellular proliferation and disorganized islet growth. Intercrossing the individual Ins-EGF and Ins-KGF transgenic mice resulted in more profound changes in pancreatic morphology including proliferation of pancreatic cells and extensive intra-islet fibrosis. Insulin-producing beta-cells were found in some of the ducts of older Ins-EGF and Ins-EGFxKGF transgenic mice, and amylase-producing cells were observed within the islet structures of the double transgenic mice. These data suggest that both EGF and KGF are capable of affecting pancreatic differentiation and growth, and that co-expression of these molecules in islets has a more substantial impact on the pancreas than does expression of either growth factor alone.

Unmodified supported thiol/lipid bilayers: studies of structural disorder and conducting mechanism by cyclic voltammetry and AC impedance

Supported thiol/lipid bilayer assembly, one of the most spectacular bilayer systems in recent years, has provided a good model to study biomembranes because of its high mechanical stability. In this work, the structural and conducting property of unmodified Au supported octadecanethiol/phosphatidylcholine bilayers were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The forming process of bilayer was monitored by capacitance plane plot. The normalized membrane capacitance of supported bilayer is 0.52 microF cm(-2). Kinetically controlled voltammograms determined by Butler-Volmer equation were obtained for both thiol monolayer and thiol/lipid bilayer in linear sweep voltammetry. Results of EIS experiment indicate that collapsed sites and pinhole defects exist in thiol monolayer and lipid monolayer, respectively. The difference between the values of experimental and theoretical standard electron transfer rate constant indicates that the conducting mechanism of Au supported thiol monolayer is electron tunneling at collapsed sites. The conducting mechanism of Au supported thiol/lipid bilayer is attributed as the following: the electroactive species could diffuse through pinholes in the lipid monolayer and reach collapsed sites in thiol monolayer, where electron transfer occurs via a tunneling process. The fractional coverage of the lipid monolayer measure by EIS experiments is about 0.98 or higher.

Pancreatic expression of keratinocyte growth factor leads to differentiation of islet hepatocytes and proliferation of duct cells

Keratinocyte growth factor, (KGF), a member of the fibroblast growth factor (FGF) family, is involved in wound healing. It also promotes the differentiation of many epithelial tissues and proliferation of epithelial cells as well as pancreatic duct cells. Additionally, many members of the highly homologous FGF family (including KGF), influence both growth and cellular morphology in the developing embryo. We have previously observed elevated levels of KGF in our interferon-gamma transgenic mouse model of pancreatic regeneration. To understand the role of KGF in pancreatic differentiation, we generated insulin promoter-regulated KGF transgenic mice. Remarkably, we have found that ectopic KGF expression resulted in the emergence of hepatocytes within the islets of Langerhans in the pancreas. Additionally, significant intra-islet duct cell proliferation in the pancreata of transgenic KGF mice was observed. The unexpected appearance of hepatocytes and proliferation of intra-islet duct cells in the pancreata of these mice evidently stemmed directly from local exposure to KGF.

Necrotizing myopathy induced by overexpression of interferon-gamma in transgenic mice

A transgenic mouse model has been established in which the cytokine interferon-gamma (IFN-gamma) is overexpressed through the action of the acetylcholine receptor epsilon promoter acting at the neuromuscular junction. While originally developed as a model for the study of the pathogenesis of myasthenia gravis, there are important differences from both human myasthenia gravis and its animal model, experimental autoimmune myasthenia gravis. By 4 months of age there was a well-established inflammatory, predominantly necrotizing myopathy, with marked dystrophic calcification. Dystrophic and degenerative changes in terminal axons and adjacent Schwann cells were also apparent. The acetylcholine receptor was not the primary target of the inflammatory response, since at 10 weeks of age the receptor content was not decreased and antibodies were not detected bound to the receptor. The IFNgamma transgenic mouse model may provide a clinically relevant model of necrotizing myopathy for investigation of the pathological changes associated with, and presumably precipitated by, overexpression of the pro-inflammatory cytokine interferon-gamma on the neuromuscular junction, intramuscular nerves and myofibers.

[Iridoid glycosides from Pedicula dicora Franch]

OBJECTIVE

To study the components in the root of Pedicula dicora.

METHODS

Column chromatography with silica gel and polyamide was employed for the isolation and purification of ingredients. The structures were elucidated by spectral method.

RESULT

Three iridoid glycosides were obtained and elucidated as mussaenoside, shanzhiside methyl ester and lamalbid.

CONCLUSION

All the three compounds were separated from P. dicora for the first time.

[Protective effects of Ginkgo biloba extract on focal cerebral ischemia and thrombogenesis of carotid artery in rats]

Rat focal cerebral ischemia induced by occlusion and thrombogenesis of middle cerebral artery(MCAO) was used as experimental model to study the effects of extract of Ginkgo biloba (EGb) and the positive control drugs were urokinase and nimodipine on cerebral infarct size and neurological deficits. The results showed that cerebral ischemia and neurological deficits appeared in rat focal cerebral ischemic models, and the degree was of cerebral ischemia larger in occlusion model than in thrombogenesis model. The cerebral infarct size was significantly smaller and neurological deficits greatly improved at large dose of EGb(200 mg.kg-1, i.v.), the preventive effect appeared to be better than the treatment effect. The positive control drugs urokinase and nimodipine were also shown to distinctly decrease the cerebral infarct size and improve the neurological deficits in the models. Small dose of EGb(100 mg.kg-1, i.v.) was found to decrease the cerebral infarct size of thrombogenesis model, and improve neurological deficits of both thrombogenesis and occlusion model. EGb was also shown to inhibit the thrombogensis of rat common carotid artery stimulated by electrical current in dose-dependent manner. This experiment indicates that EGb might have beneficial effects on prevention and treatment of ischemic stroke and thrombogenesis.

[An approach to operative treatment for acute abdomen complicated by malignant hemopathy]

The experience of operative treatment in 14 cases of acute abdomen complicated by malignant hemopathy was reported. Primary diseases consisted of AL, NHL, MM, MH and MDS-RA, 13 cases of them were at progressing stage. The acute abdominal conditions included acute appendicitis, acute pancreatitis, acute cholecystitis, peritonitis secondary to intestinal perforation, intestinal obstruction, primary peritonitis and ileocecal syndrome. The type of acute abdomen was related with primary desease and chemotherapy. 8 cases were operated and 2 of them died of complications after operation. Biopsy of excised tissue showed tumor cells in 2 cases. The rate of correllation between preoper active and postoperative diagnosis was 62.5%. These findings suggest that malignant infiltration in the viscera, duration of abdominal pain before operation and the change of blood picture are the major factors for determining operative indication and the postoperative prognosis.

[Chyle fistula after radical neck dissection: 3 cases reports]

3 cases of chyle fistulae were found after complete laryngectomy and radical neck dissection. One case was hydrothorax. Two cases were lately cervical chyle fistula. In this article the cause, diagnosis and treatment of chyle fistula were discussed.

[Vitrectomy for the treatment of retinal detachment uncomplicated by advanced proliferative vistreoretinopathy]

PURPOSE

To determine the role of vitrectomy be used in retinal detachment uncomplicated by proliferative vitreoretinopathy (PVR).

METHODS

We studied 54 cases who had undergone vitrectomy for retinal detachment uncomplicated by severe proliferative vitreoretinopathy. The indications for vitrectomy fell into three main groups: 1) retineal detachment of PVR-B (n = 15), 2) Retinal breaks at the posterior of PVR-C1 or C2 (n = 11), 3) retinal view was poor (n = 28).

RESULTS

The success rate with one procedure was 74% and with further surgery retinal reattachment was achieved in 96%. After surgery, the visual acuity was improved in 43 eyes (79.6%) unchanged in 9 eyes (16.7%), and worse in 2 eyes (3.7%).

CONCLUSION

Vitrectomy is an effective method for treatment of selected cases of retinal detachment uncomplicated by proliferative vitreoretinopathy.

[Incorporation of cortical allograft: a biomechanical study]

OBJECTIVE

To explore the changes of biomechanical properties of cortical allograft in different mechanical environments.

METHOD

Cortical allograft was transplanted to each side of the midshaft diaphyseal ulnar of 40 rabbits. The left transplanted allograft underwent normal physiological load, while the right underwent lower load. Animals were killed and specimens taken for examination of bone mineral density, bone porosity and maximal three-point-bend breaking load.

RESULT

The union strength of allograft-host bone junction increased constantly, while the internal creeping substitution led to an initial greater weakening of the cortical allograft itself and the later recovery of its strength. In comparison, the union strength of the normally loaded graft-host surface was significantly higher than that of the lower loaded side at eight and sixteen weeks after transplantation. At the sixteenth week, there was greater bone strength in normally loaded graft than that in less loaded graft.

CONCLUSION

The internal repair would lead to initial greater weakening of cortical allograft and the later gradual recovery of its strength. The effect of physiological load can accelerate the improvement of the biomechanical properties of allograft.

Endocrine/exocrine intermediate cells in streptozotocin-treated Ins-IFN-gamma transgenic mice

To trace the ontogeny of beta cell regrowth in adult transgenic mice that produce interferon-gamma in the islets (ins-IFN-gamma), their existing beta cells were depleted by treatment with high doses of streptozotocin (STZ). Initially, beta cell necrosis and degranulation were apparent in STZ-treated mice of both the BALB/c and the ins-IFN-gamma transgenic strains. The newly emerging transitional cells were then characterized by ultrastructural analysis. Interestingly, transitional cells harboring both exocrine and endocrine granules appeared frequently in ins-IFN-gamma transgenics after high-dose STZ treatment. New beta cells were produced primarily by the formation of new islets from the small pancreatic ducts. Beta cell regeneration in the ins-IFN-gamma transgenic mouse model is thus explained primarily by the budding of new islets from the ducts with acinar cells as possible precursors of islet cells.

alpha-Cell neogenesis in an animal model of IDDM

Currently there is debate regarding the capacity of pancreatic islets to regenerate in adult animals. Because pancreatic endocrine cells are thought to arise from duct cells, we examined the pancreatic ductal epithelium of the diabetic NOD mouse for evidence of islet neogenesis. We have evidence of duct proliferation as well as ductal cell differentiation, as suggested by bromodeoxyuridine-labeling and the presence of glucagon-containing cells within these ducts. In addition, the ductal epithelia in diabetic NOD mice expressed the neuroendocrine markers neuropeptide Y and tyrosine hydroxylase. These ducts also expressed the homeobox gene product, insulin promoter factor 1. Ductal cell proliferation and expression of these markers was not observed in transgenic NOD mice (NOD-E), which do not develop clinical or histopathological symptoms of IDDM. This suggests that the observed ductal cell proliferation and differentiation was a direct result of beta-cell destruction and insulin insufficiency in these adult diabetic mice, which further suggests that these events are recapitulating islet ontogeny observed during embryogenesis. It is possible that comparable processes occur in the human diabetic pancreas.

Long-term prognosis of percutaneous transluminal coronary angioplasty in 229 cases

OBJECTIVE

To evaluate long-term efficacy of percutaneous transluminal coronary angioplasty (PTCA) and the factors affecting its efficacy in Chinese patients.

METHODS

Two hundred and twenty-nine patients who underwent successful PTCA in this institution were followed-up by direct interview or letters. The rate of follow-up was 95%. The period of follow-up were 0.5-8.4 (with mean of 2.3 +/- 1.8 years).

RESULTS

Angina Pectoris recurred in 76 (33.2%) of the patients. Cox regression analysis revealed that the relative risk of recurrence of angina pectoris was increased among the patients with triple vessel disease and with history of hypertension. During the period of follow-up, 2 (0.9%) patients died, 6 (2.6%) had non-fatal acute myocardial infarction, 4 (1.7%) had coronary artery bypass graft surgery and 29 (12.7%) had repeat PTCA. The cardiac event-free survival rate calculated by Kaplan-Meier method was 84.8% at the first year and 70.5% at the eighth year. Cox regression analysis revealed that there were positive correlation between the relative risks of cardiac events and stenosis of lesions before PTCA and residual stenosis of LAD after PTCA.

CONCLUSION

The long-term efficacy of PTCA in Chinese patients was good. The results of this study suggest that to decrease the residual stenosis of LAD during procedures could probably decrease the relative risk of cardiac events during follow-up.

Interdecadal Climate Fluctuations That Depend on Exchanges Between the Tropics and Extratropics

The unexpected and prolonged persistence of warm conditions over the tropical Pacific during the early 1990s can be attributed to an interdecadal climate fluctuation that involves changes in the properties of the equatorial thermocline arising as a result of an influx of water with anomalous temperatures from higher latitudes. The influx affects equatorial sea-surface temperatures and hence the tropical and extratropical winds that in turn affect the influx. A simple model demonstrates that these processes can give rise to continual interdecadal oscillations.

Structural alterations of resistance vessels of spontaneously hypertensive rats and protective effects of captopril

OBJECTIVE

To observe the structural alterations of resistance vessels in spontaneously hypertensive rats (SHRs) and to evaluate the effects of captopril on them.

METHODS

15-week-old male SHRs were treated with oral captopril (100 mg/kg/day) for 12 weeks. Age- and sex-matched SHRs and Wistar-Kyoto rats (WKY) were fed under the same conditions without captopril administration for the same duration. All rats were killed at the age of 27 weeks. The structural parameters included media width, lumen diameter, media-lumen ratio, vascular collagen area (VCA) and vascular collagen density (VCD). The media width, lumen diameter and media-lumen ratio were measured in hhematoxylin and eosin staining sections under a direct light microscope and VCA and VCD in picrosirius red staining sections under a polarizing light microscope. All the values were processed with a computer image analyzer.

RESULTS

There were thicker media width, smaller lumen diameter, higher media-lumen ratio and larger VCA in untreated SHRs than in WKY. Captopril inhibited media thickening, with lumen diameter decreasing, media-lumen ratio increasing and VCA enlarging. There was no significant difference in VCD among the three groups.

CONCLUSIONS

Adverse structural alterations occur in resistance vessels of SHRs and captopril may prevent their progression.

Determination of nerve conduction velocity distribution from sampled compound action potential signals

The sampled compound action potential (CAP) data sequence was expressed as the circular convolution of the delay sequence and the sampled single fiber action potential (SFAP) data sequence. An algorithm, based on Hirose's method [1], was then developed to separate the delay sequence from the sampled CAP data sequence, and the nerve conduction velocity distribution (NCVD) was consequently calculated from the delay sequence. The NCVD was found to be the product of the amplitude of the SFAP and the number of fibers. Simulations show that the estimated results were in good agreement with the calculated results. Experiments were performed on ten sciatic nerves from five bullfrogs (Rana pipens) using two independent variables: interelectrode distance and stimulus current strength. The results estimated from CAP's recorded under each condition reflect the corresponding feature of NCVD of the condition. The advantage of the technique is to provide detailed information about both slow and fast conducting fibers. This technique also offers the possibility to directly calculate the nerve fiber diameter distribution from the sampled CAP data sequences.

Growth factors in the regenerating pancreas of gamma-interferon transgenic mice

We examined the distribution of several relevant growth factors in gamma-interferon transgenic mice, which undergo continual growth and differentiation in the pancreas. As a result, epidermal growth factor (EGF), TGF-alpha, and the EGF receptor were identified as potentially important in mediating some of these regenerative changes. Transient up-regulation of EGF, TGF-alpha, and the EGF receptor were observed in acini undergoing differentiation into duct-like structures. These ducts have been shown to proliferate and potentiate regeneration of the pancreatic islet mass.

Transgenic mice expressing IFN-gamma in pancreatic beta-cells are resistant to streptozotocin-induced diabetes

In 28 adult Ins-IFN-gamma transgenic mice, injection of high doses of streptozotocin (STZ; first injection, 300 microgram/g body weight; second injection, 200 microgram/g body weight 4 h later) failed to induce severe hyperglycemia. To the contrary, 28 BALB/c mice developed diabetes mellitus after identical injections of STZ. Because the STZ-induced islet damage was partially inhibited in Ins-IFN-gamma transgenic mice, their glycemia levels became normal 4 days after STZ administration. Both transgenic and BALB/c mice lost weight after receiving STZ, but the body weights of transgenic mice then returned to pretreatment levels in a nearly parallel manner with the glycemia. Immunolabeling with insulin identified an unusual spreading pattern of insulin immunoreactivity. Ultrastructural observations confirmed that beta-cell necrosis and degranulation were more severe in STZ-treated BALB/c than in Ins-IFN-gamma transgenic mice. Moreover, regeneration of pancreatic duct cells and islet neogenesis were observed in the transgenic mice. Therefore, after STZ treatment, the Ins-IFN-gamma transgenic mice apparently were resistant to the induction of severe diabetes, whereas their BALB/c age-matched counterparts succumbed to the disease.

Prevalence of hypertension and its trends in Chinese populations

The third nation-wide survey of blood pressure level and hypertension was carried out in China in 1991. In total, 950,356 residents aged > or = 15 years were examined. Sampling population were composed of half urban and half rural from 27 provinces or autonomous regions and three municipalities. The results showed that: (1) the age-adjusted prevalence rate of hypertension (systolic blood pressure > or = 140 mmHg or diastolic blood pressure > or = 90 mmHg) was 11.26% (male 12.15%, female 10.32%) and the definite hypertension rate (systolic blood pressure > or = 160 mmHg or diastolic blood pressure > or = 95 mmHg, or on medication) was 5.29% (male 5.38%, female 5.21%); rate of borderline hypertension was evaluated from 2.82% to 6.15% during the 10-year period from 1979/1980 to 1991; (2) the prevalence rate was progressively increased with age, especially after age 35; prevalence rates were generally higher in men than women before about age 44, however by age 60, women had a higher prevalence of hypertension; (3) a general trend of decrease in prevalence from north-eastern to south-western China was confirmed; (4) there were significantly lower rates in rural than in urban areas. Results of preliminary analysis for prevalence of hypertension among different occupations, nationalities, and educational levels were presented.

Treatment of IFN-gamma transgenic mice with anti-IFN-gamma reveals the remodeling capacity of the adult pancreas

Pancreatic expression of gamma-interferon (IFN-gamma) initiates a cascade of pathogenic changes that include pancreatic inflammation, islet cell destruction, hyperglycemia, and islet regeneration. In this study, we explore the developmental plasticity of the adult pancreas and particularly its ability to return to normoglycemia and to remodel itself from an advanced pathogenic state. This was approached by treating adult transgenic mice with a pulse of anti-IFN-gamma antibody and determining the functional and morphological status of the pancreas. We demonstrated that anti-IFN-gamma antibody administration led to the reduction of hyperglycemic blood glucose levels in transgenic mice. We also observed that the pancreas returned from a profoundly perturbed state toward normality. Analysis of the mitotic index indicated that cell proliferation previously associated with islet cell regeneration was greatly reduced after anti-IFN-gamma administration. Our results highlight the ability of the adult pancreas to remodel itself and return from a complex pathological state to normalcy once the trophic signal inducing this pathology is removed. These data also suggest that anti-IFN-gamma administration may have important clinical implications for treatment of chronic pancreatitis in humans.

The role of infiltrating macrophages in islet destruction and regrowth in a transgenic model

The expression of interferon-gamma (IFN-gamma) in pancreatic beta cells leads to a complex pathology that represents the processes of both islet destruction and islet regeneration. Inflammatory cells and the factors elicited from them participate in the development of pathology in this transgenic model. To dissect the role of infiltrating macrophages in these events, the monoclonal directed against the type 3 complement receptor (5C6) was utilized to inhibit the extravasation of macrophages. This was approached by treating transgenic mice with 5C6 for 3 or 4 months, starting from 5-7 days of age. The data presented in this report demonstrate that infiltrating macrophages are important in the observed induction of diabetes in our transgenic model. We also found that infiltrating macrophages did not play a major role in the observed proliferation and islet regeneration, but some interesting subtleties regarding the regulation of this proliferative process emerged.

Accumulation of extracellular matrix and developmental dysregulation in the pancreas by transgenic production of transforming growth factor-beta 1

Transgenic mice expressing transforming growth factor-beta 1 (TGF-beta 1) in the pancreatic beta-islet cells directed by human insulin promoter were produced to study in vivo effects of TGF-beta 1. Fibroblast proliferation and abnormal deposition of extracellular matrix were observed from birth onward, finally replacing almost all the exocrine pancreas. Cellular infiltrates comprising macrophages and neutrophils were also observed. Plasminogen activator inhibitor was induced in the transgenic pancreas as well as fibronectin and laminin, partly explaining accumulation of extracellular matrix. TGF-beta 1 inhibited proliferation of acinar cells in vivo as evidenced by decreased bromodeoxyuridine incorporation. Development of pancreatic islets was dysregulated, resulting in small islet cell clusters without formation of normal adult islets; however, the overall islet cell mass was not significantly diminished. Additional transgenic lines with less pronounced phenotypes had less expression of TGF-beta 1 transgene. These findings suggest that TGF-beta 1 might be a mediator of diseases associated with extracellular matrix deposition such as chronic pancreatitis, and this mouse model will be useful for further analysis of the in vivo effects of TGF-beta 1, including its potential for immunosuppression.

Cellular and humoral immune responses to adenoviral vectors containing factor IX gene: tolerization of factor IX and vector antigens allows for long-term expression

Recombinant adenoviruses containing the canine factor IX (FIX) cDNA were directly introduced in the hind leg muscle of mice. We show that (i) in nude mice, high expression (1-5 micrograms/ml in plasma) of FIX protein can be detected for > 300 days; (ii) in contrast, expression of FIX protein was transient (7-10 days) in normal mice; (iii) CD8+ lymphocytes could be detected within 3 days in the infected muscle tissue; (iv) use of beta 2-microglobulin and immunoglobulin M heavy chain "knockout" mice showed that lack of sustained expression of FIX protein is due to cell-mediated and humoral immune responses; (v) normal mice, once infected with recombinant adenovirus, could not be reinfected efficiently for at least 30 days due to neutralizing viral antibodies; and, finally, (vi) using immunosuppressive drugs, some normal mice can be tolerized to produce and secrete FIX protein for > 5 months. We conclude that currently available adenoviral vectors have serious limitations for use for long-term gene therapy.

Myasthenia gravis-like syndrome induced by expression of interferon gamma in the neuromuscular junction

Abnormal humoral responses toward motor end plate constituents in muscle induce myasthenia gravis (MG). To study the etiology of this disease, and whether it could be induced by host defense molecules, we examined the consequences of interferon (IFN) gamma production within the neuromuscular junction of transgenic mice. The transgenic mice exhibited gradually increasing muscular weakness, flaccid paralysis, and functional disruption of the neuromuscular junction that was reversed after administration of an inhibitor of acetylcholinesterase, features which are strikingly similar to human MG. Furthermore, histological examination revealed infiltration of mononuclear cells and autoantibody deposition at motor end plates. Immunoprecipitation analysis indicated that a previously unidentified 87-kD target antigen was recognized by sera from transgenic mice and also by sera from the majority of human MG patients studied. These results suggest that expression of IFN-gamma at motor end plates provokes an autoimmune humoral response, similar to human MG, thus linking the expression of this factor with development of this disease.

Transitional cells in the regenerating pancreas

We examined the spectrum of intermediate cell types in the regenerating pancreas as duct epithelial cells progressed through their differentiation pathway to become mature endocrine cells. The model used was transgenic mice in which the pancreatic islets continue to grow during adulthood, unlike normal mice whose islet cell formation ceases early in life. Because the intermediate cells migrated into islet-like clusters at specific locations, we propose a specific pathway for islet development. Endocrine cells are derived from duct cells co-expressing a duct cell antigen, carbonic anhydrase II (CA II) and an exocrine enzyme, amylase. The CA II/amylase cells become amylase/endocrine intermediate cells as they exited from their lumenal location. The abluminal amylase/endocrine cells continue to differentiate to multihormone-bearing young endocrine cells, which migrated to form clusters with other differentiating endocrine cells.

Postnatal anti-interferon-gamma treatment prevents pancreatic inflammation in transgenic mice with beta-cell expression of interferon-gamma

beta-Cell-targeted expression of interferon-gamma (IFN-gamma) leads to pancreatitis and immune sensitization to beta-cells. This transgenic model is used to explore the possible role of locally produced IFN-gamma in loss of tolerance to beta-cell-specific antigens in insulin-dependent diabetes mellitus (IDDM). The aim of the present study was to test if postnatal treatment with antibodies against IFN-gamma could inhibit morphological changes in the IFN-gamma transgenic pancreas, even though the transgene is expressed during embryogenesis. Treatment with a monoclonal rat anti-mouse IFN-gamma antibody for 6 weeks, starting from 5 to 7 days of age, completely inhibited IFN-gamma-induced morphological changes in the pancreas, and only a modest inflammatory reaction emerged after prolonged treatment for 12 weeks. The lack of morphological changes may reflect the ability of nonterminally differentiated neonatal pancreatic cells to compensate for transgene-induced pathological alterations occurring in utero prior to the antibody treatment. We conclude that inflammation and altered pancreas morphology in the transgenic mice is the result of the biological actions of IFN-gamma and not by disrupted islet development due to transgene overexpression in the pancreatic beta-cells. Furthermore, our treatment schedule can serve as a model for future intervention studies in the transgenic mice, elaborating the role of IFN-gamma in localized inflammatory reactions, IDDM in particular.

A transgenic model for studying islet development

The regeneration of islet cells in a transgenic mouse strain harboring the interferon-gamma gene (IFN-gamma) linked to the insulin promoter DNA fragment (ins-IFN-gamma) is described. The regeneration follows the loss of islets by an immune response provoked by IFN-gamma and manifests in the proliferation of duct cells, the presence of progenitor cells, and the formation of buds and isletlike structure. All three types (A, B, and D) of four endocrine cells identified by immunolabeling are present. The progenitor cells express neuronal enzymes, tyrosine hydroxylase (TH) and glutamic acid decarboxylase (GAD), as revealed by specific antibodies. The results indicate that the islet regeneration closely resembles the embryonic islet differentiation and serves as a model for studying islet development. The expression of neuronal enzymes by islet progenitor cells signifies yet unknown relationships to the nervous tissue. GAD, recognized as an autoantigen in insulin-dependent diabetes mellitus (IDDM) and stiff-man syndrome, may provide a clue to the mechanism of autoimmune disease.

[Research on anti-idiotypic antibodies to bovine abortus]

Based on the establishment of McAbs to a local Brucella strain S85A, the McAb A7 was selected and tested as a protective one. Using A7 to immunize rabbits, we got high titer anti-idiotypic antibodies which were then proved to possess internal image by competitive inhibiting ELISA and catch blocking ELISA. The anti-idiotypic antibodies were then purified and mixed with glycerin to immunize guinea pigs and mice. The results showed that: immunized guinea pigs and mice had produced certain titer antibodies to Brucella. 79.2% of immunized guinea pigs had been protected from the challenge of 544A 4 months later from primary immunization. The number of T ANAE+ in peripheral blood of immunized mice had increased significantly compared to controls. These results suggest that the anti-idiotypic antibodies not only possess the antigen internal image but have the available immunogenicity stimulate animals producing Ab3 and make them get free from the infection.

Dependence of viscoelastic properties on spacer length and molecular weight for a side-chain liquid crystal polymer in a nematic solvent

The light scattering technique was used to investigate the viscoelastic parapeters characterizing director distortions in miscible mixtures of pentacyanobiphenyl (5CB) with a side-chain liquid crystal polymer (LCP) having different spacer lengths (n=2, 3, 5, 7, 11). To separate the elastic constants from the corresponding viscosities, two approaches were attempted: (a) an AC electric field was applied to homeotropically-aligned nematic monodomains of the mixtures, and the field-dependent scattering intensities and director distortion relaxation rates were measured to obtain the twist viscosity γ1 and elastic constant K22; (b) an electric field was applied to a homogeneously aligned monodomain and the votage-dependent capacitance and the threshold voltage were measured to obtain the dielectric constants and the splay elastic constant. The remaining splay viscosity, bend viscosity and bend elastic constant were subsequently determined by fitting the angular-dependent relaxation rates in three scattering geometries which correspond principally to splay, twist, and bend modes of the director distortions ofr nematic miwtures. The additin of liquid crystal polymers cause significant decreases of the relaxation rates for all three distortion modes of 5CB which are due to small decreases in the elastic constants and large increases in the viscosity coefficients. The molecular weight dependence of the viscosities for n=3 is weak. The largest increase in viscosities is found for the LCP with shortest spacer length n=2. The dependence of viscosity on spacer length disappears when n≥5. The anisotropy in the three viscosity incrementsof the nematic mixtures also becomes smaller when n≥5. Our results indicate that, for side-chain LCPs in a nematic solvent, the backbone configurational anisotropy is enhanced by a strong coupling between the mesogenic group in the side-chain and the chain backbone.

Epithelial cell proliferation and islet neogenesis in IFN-g transgenic mice

We have identified a model system for the study of pancreatic islet development and regeneration in transgenic mice bearing the interferon-gamma (IFN-g) gene expressed in the pancreatic islets. Previous studies showed that the locally produced IFN-g causes lymphocyte infiltration and islet cell destruction. Here we demonstrate that new islet cells are formed continuously from duct cells as evidenced by (1) the dramatic proliferation of duct cells, (2) the appearance of primitive cells and (3) their subsequent differentiation to endocrine cells. The IFN-g induced islet neogenesis is similar to embryonic islet morphogenesis and offers a model system for studying factors modulating islet development. Additionally, the duct cells occasionally transdifferentiate to gastrointestinal-like cell types and hepatocytes. These results underscore the lymphokine's ability to initiate a complex ‘transdifferentiation’ pathway, providing a window for understanding lineage interrelationships within a terminally differentiated structure.

Diagnostic exploration of enlarged peripheral nerves in suspected cases of leprosy. An analysis of 55 cases

In 55 cases presenting with enlarged peripheral nerves without any skin lesions, a rice grain-sized biopsy of the nerve lesion was taken for histopathological examination. As a result definitive diagnoses could be established: leprosy was diagnosed in 32 cases. In 23 cases the cause of nerve enlargement was not leprosy: post-traumatic neuritis 9, cysts 5, hypertrophic neuritis 3, nonspecific 4, neurofibroma 1, and amyloidosis 1. In all of these cases there was a deficit of the nerve function and postoperatively there were no complications. The authors, as a result of this experience, believe that surgical exploration and biopsy is a harmless diagnostic tool for establishing a definitive diagnosis of leprosy in cases presenting with enlarged peripheral nerves without any skin lesions. In 23 out of 55 such cases the nerve enlargement was proved to be other causes than leprosy.

Regeneration of pancreatic endocrine cells in interferon-gamma transgenic mice

We have shown that the pancreatic duct cells of IFN-gamma mouse are actively multiplying and that many duct cells differentiate to become endocrine cells. This islet regenerating process closely parallels the islet development during normal organogenesis in the fetus and offers a model for studying the cell lineage relationships of islet cells. The subject has received wide interest and intensive research in recent years. One of the noteworthy results of this study is the finding that duct cells retain the ability to proliferate and to differentiate into islet cells. Under normal conditions, duct cells do not continue to multiply or to differentiate. The results suggest that in the transgenic mice, the progenitor cells of embryonic multipotential duct cells transform into adult cells, but in the presence of appropriate signals or stimuli can resume their multipotential property. The appearance of hepatocytes indicates that while the cell proliferation observed largely results in endocrine cells, other differentiation pathways are occasionally possible. We also detect a few large cells containing albumin and alpha-fetoprotein in the periductal area. Pancreatic hepatocytes have also been observed in the rat after recovery from copper deficiency diet. Thus, the regeneration of islet cells in transgenic mice provides a model system for the study of factors modulating the growth pattern as well as the differentiation pathway.