Adrenergic overload and apoptosis in heart failure: implications for therapy

Sympathetic nervous system activity to the myocardium is increased in patients with heart failure. It is now appreciated that norepinephrine (NE), the primary sympathetic neurotransmitter, can exert direct adverse effects on cardiac myocytes and might thereby contribute to pathological remodeling, a chronic process which leads to progressive left ventricular (LV) chamber dilation and loss of contractile function. The demonstration of apoptosis in failing human hearts has led to the thesis that continuing loss of viable myocytes is a mechanism for progressive myocardial failure. For many years it has been appreciated that chronic exposure to catecholamines can exert a toxic effect on the myocardium. In vitro studies in cultured cardiac myocytes show that tonic exposure to NE increases the number of apoptotic myocytes via stimulation of the beta-adrenergic receptor (beta-AR) pathway. Interestingly, a beta1-AR selective antagonist completely prevented NE-stimulated apoptosis, whereas a beta2-AR selective antagonist increased the amount of apoptosis, suggesting that beta1- versus beta2-AR may couple to different signaling pathways. In rats, isoproterenol infusion for as little as 12 hours increased the frequency of terminal deoxynucleotidyltransferase-mediated nick end-labeling (TUNEL)-positive myocytes. Likewise, mice that overexpress beta1-AR or G alpha s in the myocardium develop left ventricular dilation, contractile dysfunction and apoptosis. Although the link between apoptosis and myocardial failure remains to be proven, these in vitro and in vivo observations provide a rational mechanism by which beta-AR antagonists may help to prevent or slow LV remodeling and failure in patients.

Gynaecology in the new millennium

Great challenges await the gynaecologist in the 21st century. While advances in medical technology necessitate that gynaecology move more towards a medical discipline than a surgical one, gynaecologists will be expected to play an increasingly important role in the modern woman's life. This fundamental change is influenced by four main factors, namely, the world's aging population, spread of information technology, advances in molecular based medical therapy, and the changing lifestyle of the woman in the next century. Our role cannot get any lesser as we continue to advise, educate and facilitate the lives of women, and we must aspire a new generation of responsible gynaecologists to continue this ambition.

Budd-Chiari syndrome: our experience of 71 patients

BACKGROUND

Hepatic venous outflow obstruction (Budd-Chiari syndrome) is frequently encountered as a cause of portal hypertension at our centre.

METHODS AND RESULTS

We studied the clinical presentation, therapeutic modalities and outcome of 71 patients with hepatic venous outflow obstruction between 1992 and 1997. Twenty-seven patients presented with acute disease, while 44 had chronic presentation. Abdominal pain, distension, jaundice and upper gastrointestinal bleeding were the commonest presenting symptoms. The majority of patients had distended veins, hepatomegaly, splenomegaly, ascites and ankle oedema. The diagnosis was made on the basis of inferior vena cavography/functional hepatography and pulsed Doppler ultrasonography and/or liver biopsy in 39 patients and pulsed Doppler ultrasonography and/or liver biopsy in 32 patients. Pulsed Doppler ultrasonography accurately detected the site of the block in 31 of 39 patients (79.4%). The obstruction was in the hepatic vein in 20 patients, in the inferior vena cava in 10, and in both in 41 patients. Aetiologically, four had pregnancy-related disease, four tumour-related, three hypercoagulable states, 18 inferior vena cava membranes and 42 were idiopathic. Of 30 patients in whom liver biopsy was carried out, eight had centrizonal congestion and necrosis, 13 had mixed features and nine had established cirrhosis. Seven patients underwent a shunt operation and surgical membranotomy was carried out in one. Three patients (4.2%) died in the hospital.

CONCLUSIONS

Hepatic venous outflow obstruction is a common problem; patients present with abdominal pain, distension, jaundice, distended veins, ascites and ankle oedema. Chronic presentation is more frequent. Pulsed Doppler ultrasound, venography and liver biopsy are very helpful in diagnosis.

Myocardial-directed overexpression of the human beta(1)-adrenergic receptor in transgenic mice

The beta(1)-adrenergic receptor (AR) is the dominant subtype in non-failing and failing myocardium. beta(1)-AR signaling, by the endogenous neurotransmitter norepinephrine, is central to the regulation of myocardial contractility. In heart failure, the beta(1)-AR undergoes subtype-selective downregulation which may protect against the increased cardiac adrenergic drive associated with this pathophysiological state. To examine the hypothesis that chronically increased beta(1)-AR mediated signaling has adverse myocardial effects, transgenic mice overexpressing the human beta(1)-AR in a cardiac-selective context were produced, utilizing an alpha-myosin heavy chain (MHC) promoter. In these mice, beta(1)-AR protein abundance was approximately 24-46-fold (1-2 pmol/mg protein) that of wild-type mice. Histopathological examination of young (4 months old) and old (approximately 9 months old) transgenic mouse hearts consistently demonstrated large areas of interstitial replacement fibrosis, marked myocyte hypertrophy and myofibrilar disarray. In addition, increased expression of the pre-apoptotic marker, Bax, was observed coincident with regions of fibrosis accompanied by an increased apoptotic index, as measured by TUNEL assay. Older non-transgenic mice exhibited a slight tendency towards a decreased fractional shortening, whereas older beta(1)-AR transgenic mice had a marked reduction in fractional shortening (%FS approximately 30) as determined by echocardiography. Additionally, older beta(1)-AR transgenic mice had an increased left ventricular chamber size. In summary, cardiac-directed overexpression of the human beta(1)-AR in transgenic mice leads to a significant histopathological phenotype with no apparent functional consequence in younger mice and a variable degree of cardiac dysfunction in older animals. This model system may ultimately prove useful for investigating the biological basis of adrenergically-mediated myocardial damage in humans.

Protective efficacy of trypsin inhibitor on the the gut following rotavirus infection in malnourished infant mice

Epidemiologic data suggest a close relationship between protein energy malnutrition (or protein energy malnourished) (PEM) and development of infectious diarrheal diseases. In the present studies, the impact of trypsin inhibitor (TI) on the gut following rotavirus (RV) infection was investigated in PEM young growing inbred balb/c mice. The animals were divided into four groups: (1) control; (2) PEM; (3) PEM+RV and (4) PEM+ RV+TI. Control and PEM animals were orally inoculated with normal saline, PEM+RV animals were given 50 microl RV (100ID50) and PEM+RV+TI animals were inoculated with 0.6 mg TI/g body weight + 50 micronl RV. The body weight of each animal was recorded. Six animals from each group were sacrificed on days 0, 1, 3, 5, 7 and 10 post inoculation by cervical dislocation. The intestines were removed, everted and homogenized in ice-cold saline. Leucine aminopeptidase (LAP), glutathione (GSH) levels and L-leucine uptake were determined in the jejunum and ileum. Body weight was decreased in PEM and PEM+RV groups compared to the controls. LAP and leucine uptake levels were elevated in the PEM group but decreased in the PEM+RV group. GSH levels were decreased in the PEM+RV group. Enzyme activity, GSH and LAP uptake levels were restored in the PEM+RV+TI group. The study shows the protective role of soybean TI against RV infection in malnourished mice.

Helicobacter pylori infection in chronic smokers with non ulcer dyspepsia

BACKGROUND/AIMS

Both H. pylori infection and smoking are risk factors for acid peptic disorders. There is paucity of data on relationship between smoking and H. pylori infection. Therefore, we studied prevalence of H. pylori infection in smokers with non-ulcer dyspepsia (NUD).

PATIENTS AND METHODS

30 smokers with NUD (age 29.5 +/- 1.2 years; all men) and 30 non-smokers with NUD (age 29.2 +/- 1.6 years; all men) were included. None was on antiulcer drugs or antibiotics for more than 2 weeks. Upper gastrointestinal endoscopy was performed and antral biopsies obtained were subjected to rapid urease test, Gram's staining, culture and histopathology. Patient was considered H. pylori positive, if culture was positive or combination of histopathology plus rapid urease test or Gram's staining plus rapid urease test was positive.

RESULTS

24 of 30 (80%) smokers and 13 of 30 (43%) non smokers were positive for H. pylori infection (p < 0.001). There was no significant difference in the positivity of H. pylori in light (78%), moderate (81%) and heavy smokers (80%). All the 37 patients who were positive for H. pylori had histological gastritis compared to 65% in H. pylori negative patients. However there was no difference in presence of histological gastritis among H. pylori negative smokers (33%) and non smokers (70%; p = NS).

CONCLUSIONS

H. pylori infection is more common in smokers with NUD than in non-smokers. However duration and amount of smoking has no relationship with H. pylori positivity.

Intestinal pseudo-obstruction due to neurofibromatosis responding to cisapride

Gastrointestinal involvement in neurofibromatosis presenting with mechanical obstruction, hemorrhage or intussusception is known. Small bowel dysmotility and intestinal pseudo-obstruction due to neurofibromatosis is rare. A 23-year-old man with classical neurofibromatosis presented with intermittent episodes of intestinal pseudo-obstruction, small bowel bacterial overgrowth and steatorrhea. The patient had good symptomatic improvement with cisapride.

Gastrointestinal bleeding due to worm infestation, with negative upper gastrointestinal endoscopy findings: impact of enteroscopy

BACKGROUND AND STUDY AIMS

In cases of hookworm and roundworm infestation, chronic occult bleeding is well known, but acute gastrointestinal bleeding is rarely described. We report five patients with worm infestation who presented with acute massive gastrointestinal bleeding.

PATIENTS AND METHODS

Over 1 year, we have encountered 15 patients with obscure gastrointestinal bleeding. All the patients had normal findings on upper gastrointestinal endoscopy. Push enteroscopy was performed in each patient and evaluation of the proximal 40-50 cm of the jejunum was done.

RESULTS

Five patients (four men, one woman; average age 50 yr, range 40-60) had worm infestation (two hookworm, three roundworm). All the patients had gastrointestinal bleeding (five had melena, one hematemesis, and two hematochezia) for a duration of 7-14 days. Hemoglobin ranged from 2.8 to 9 g/dl. Push enteroscopy revealed fresh blood in the jejunum, multiple erosions, and hookworms in two patients and roundworms in three patients. Hookworms were retrieved endoscopically in two patients whereas roundworms could be retrieved in only one patient. All the patients were treated with mebendazole (100 mg twice a day for 3 days), iron, and folic acid. Gastrointestinal bleeding subsided in all the patients.

CONCLUSIONS

In developing countries, worm infestation should be considered an important cause of obscure acute gastrointestinal bleeding. Evaluation of the jejunum using an enteroscope will result in more frequent diagnosis of worms as a cause of acute gastrointestinal bleeding which might have been classified as obscure gastrointestinal bleeding.

Race-related stress among Asian American veterans: a model to enhance diagnosis and treatment

This article addresses theoretical principles and clinical descriptions of the phenomenon of race-related stress and trauma experienced by Asian American Vietnam veterans. A conceptual model of race-based stress is presented, comprised of five principles, by which to understand mental health difficulties that can arise in regard to race-based stressors. The model describes (a) the relationship between life threat and physical similarity to the "enemy," (b) the relationship between fear and prejudice, (c) dehumanization as it impacts race hate and combat indoctrination, (d) additive life threat related to exploitation of one's physical similarity to the "enemy," and (e) race-based remorse. The article delineates factors affecting treatment seeking and disclosure of race-based stresses, guidelines for interviewing veterans about race-related events and ethnic self-worth, and the harmful effects of race hate.

Immunohistochemical localization and correlation of p53 and PCNA expression in breast carcinoma

The object of the present study is to detect the p53 tumour suppressor gene and proliferation cell nuclear antigen (PCNA) expression in breast carcinoma by immunohistochemistry and correlate them with the prognostic parameters. Total 35 cases of primary breast carcinoma were studied and classified histologically. Paraffin sections were stained by using monoclonal antibody D07 for p53 protein and PC-10 for PCNA. Out of 35 cases, 16 (45.7%) were p53 positive and 25 (71.4%) were PCNA positive. The mean PCNA labelling index (PCNA LI +/- SD) was 58.97 +/- 22.72 in tumors positive for both p53+ and PCNA+ while cases negative for p53- and positive for PCNA+ has higher PCNA LI +/- SD (59.24 +/- 18.97). The difference in the two groups was not significant. Most cases were positive for both p53+ and PCNA+ in the age group < 30 with higher mean PCNA LI +/- SD (62.20 +/- 27.13) than in the group > 30 (57.88 +/- 18.47). In the pre-menopausal group 57.1% cases were positive for p53+ with higher PCNA LI +/- SD (59.94 +/- 24.22). Maximum p53 and PCNA positivity was observed in grade III tumors (63.2% and 84.2%). The mean PCNA LI +/- SD was also highest in grade III carcinomas (66.83 +/- 13.97). No significant correlation was found between p53 and PCNA status with morphological type and tumour size except that logistic regression showed a positive correlation with tumour grade. Therefore the present study suggests that both p53 expression and PCNA are markers of poor differentiation in breast cancer.

The efficacy of ECT in mixed affective states

ECT is efficacious in the treatment of both the depressed and manic phases of bipolar disorder. While ECT is believed to be equally efficacious in the treatment of mixed affective states, to our knowledge there are no empirical studies on this issue. A chart review study was conducted to compare treatment response and clinical course in three groups of patients who received ECT in a general hospital service: bipolar depressed (n = 38), bipolar manic (n = 5), and bipolar mixed (n = 10), diagnosed by DSM-IV criteria. All three groups showed robust response rates, but the number of days of hospitalization was significantly longer in the mixed group (mean 30, SD 19.0 days) compared with the depressed group (mean 19.0, SD 10.9 days, t = 2.4, p < 0.03). There was a trend for the number of ECT treatments to be greater in the mixed compared with the depressed group. These findings indicate that patients with mixed affective states do respond well to a course of ECT, but the longer hospital stays and greater number of ECT treatments suggest that they may be more difficult to treat with ECT than patients with pure bipolar depression or bipolar mania.

Adrenergic regulation of myocardial apoptosis

Increased sympathetic nerve activity to the myocardium is a central feature in patients with heart failure. Norepinephrine, the primary transmitter of the sympathetic nervous system, signals via binding to alpha- and beta-adrenergic receptors (AR) that are coupled to G-proteins. Pharmacologic studies of cardiac myocytes in vitro demonstrate that beta-AR can stimulate apoptosis. Likewise, in transgenic mice overexpression of beta 1-AR or G alpha s is associated with myocyte apoptosis and the development of dilated cardiomyopathy. Whereas beta 1-AR stimulate apoptosis in vitro and in vivo, beta 2-AR may either stimulate or inhibit apoptosis and myocardial failure depending on the level of expression. Receptors coupling to Gi and Gq may also be able to mediate or modulate apoptosis and the development of myocardial failure, suggesting the potential for interactions between the beta-AR system and numerous remodeling stimuli that act through Gi or Gq signaling pathways. It appears likely that the mitogen-activated protein kinase superfamily plays a key role in mediating the actions of adrenergic pathways on myocyte apoptosis. These observations suggest that the adrenergic nervous system plays an important role in the regulation of myocyte apoptosis, and may thus contribute to the development of myocardial failure.

Effect of different combinations of MGK-264 or piperonyl butoxide with plant-derived molluscicides on snail reproduction

Effect of sublethal treatment (20% and 60% of LC(50)/24 h) of plant-derived molluscicides, viz. Polianthes tuberosa, Trachyspermum ammi, Allium sativum powder; Azadirachta indica oil; oleoresin of Zingiber officinale; and their active molluscicidal component in combination (1:5) with MGK-264 or piperonyl butoxide on the reproduction of snail Lymnaea acuminata have been studied. It was observed that the combination of plant derived molluscicide and their active molluscicidal components, viz. tigogenin, hecogenin, azadirachtin, allicin, thymol, and [6]-gingerol combination with MGK-264 or piperonyl butoxide caused a significant reduction in fecundity, hatchability, and survival of young snails. Withdrawal of snails to fresh water after the above treatment caused a significant recovery in the fecundity of L. acuminata.

Targeted inhibition of osteopontin expression in the mammary gland causes abnormal morphogenesis and lactation deficiency

Osteopontin (OPN) is a sialic acid-rich, adhesive, extracellular matrix (ECM) protein with Arg-Gly-Asp cell-binding sequence that interacts with several integrins, including alpha(v)beta(3). Since the ECM is a key regulator of mammary gland morphogenesis, and mammary epithelial cells express OPN at elevated levels, we sought to determine whether this protein plays a role in the postnatal mammary gland development. By generating transgenic mice that express OPN antisense-RNA (AS-OPN mice) in the mammary epithelia we achieved suppression of OPN production in this organ. The pregnant AS-OPN mice displayed a lack of mammary alveolar structures, a drastic reduction in the synthesis of beta-casein, whey acidic milk protein, and lactation deficiency. In agreement with these findings, we uncovered that a mammary cell line, NMuMG, which undergoes both structural and functional differentiation on ECM-coated plates, when transfected with an antisense OPN-cDNA construct, failed to undergo such differentiation. Furthermore, the results of gel-invasion assays demonstrated that these cells manifest elevated matrix metalloproteinase (MMP) activity when OPN expression is significantly reduced. The identity of this proteinase as MMP-2 is confirmed by Western blotting, zymography, and inhibition of its activity by a specific inhibitor, TIMP-2. Taken together, our results demonstrate, for the first time, an essential role of OPN in mammary gland differentiation and that the molecular mechanism(s) of its action, at least in part, involves down-regulation of MMP-2.

The subspecialty training, practice type, and geographical distribution of recently trained ophthalmologists: a study of male and female physicians

OBJECTIVE

To characterize the distribution of male and female ophthalmologists with regard to practice type, subspecialty training, rural-urban distribution, and regional distribution.

METHODS

Ophthalmology Matching Program files containing the records of residents who began their second year at accredited programs between 1986 and 1990 (inclusive), were compared to membership files of the American Academy of Ophthalmology. Practice locations for each individual were classified according to region, stage, and Rural-Urban Continuum County Code, as defined by the US Department of Agriculture.

RESULTS

This cohort comprised 2,494 individuals, 77.1% (1922) of whom were male and 22.9% (572) of whom were female. Group practice was most common (55.9% for women and 61.3% for men). More women were in salaried positions associated with health maintenance organizations (p = 0.006) and academic settings (p < 0.001) than were men. Notable differences in subspecialty choice were restricted to pediatric ophthalmology, chosen three times more frequently by women, and vitreoretinal diseases/surgery, chosen twice as often by men. Only 5.6% of women selected nonmetropolitan practice locales compared to approximately twice that percentage of men. The Middle Atlantic and New England regions attracted more women, while the South Atlantic attracted more men.

Partial characterization of a 36-kDa antigen of Entamoeba histolytica and its recognition by sera from patients with amoebiasis

A 36-kDa antigen of axenically grown pathogenic Entamoeba histolytica (HM1-IMSS) was eluted from the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)-resolved crude amoebic extract antigens. The immunoreactivity of this partially purified 36-kDa antigen with monoclonal antibody (MoAb) 3D(10) altered significantly (P<0.01) after heat and trypsin treatment but remained unaltered after treatment with sodium metaperiodate (P0.5), thereby indicating the protein nature of the epitope recognized by MoAb 3D(10). The epitope was found to be localized on the surface as well as in the cytoplasm of the E. histolytica trophozoites with the majority of it in the cytoplasm. In addition, this epitope was also found to be present on the cyst form of the parasite. The 36-kDa molecule was recognized by the sera from 29 (85%) of the 34 patients with amoebic liver abscess and five (83%) of the six patients with amoebic colitis. No serum samples from asymptomatic cyst passers, from patients with non-amoebic hepatic or intestinal disorders and apparently healthy subjects had antibodies that reacted with this 36-kDa molecule. The immune responses in man to this 36-kDa amoebic molecule indicate a potential specific role for this molecule in invasive amoebiasis.