Senescence and the SASP: many therapeutic avenues

Cellular senescence is a stress response that elicits a permanent cell cycle arrest and triggers profound phenotypic changes such as the production of a bioactive secretome, referred to as the senescence-associated secretory phenotype (SASP). Acute senescence induction protects against cancer and limits fibrosis, but lingering senescent cells drive age-related disorders. Thus, targeting senescent cells to delay aging and limit dysfunction, known as "senotherapy," is gaining momentum. While drugs that selectively kill senescent cells, termed "senolytics" are a major focus, SASP-centered approaches are emerging as alternatives to target senescence-associated diseases. Here, we summarize the regulation and functions of the SASP and highlight the therapeutic potential of SASP modulation as complimentary or an alternative to current senolytic approaches.

Characteristics and dispositional determinants of psychiatric emergencies in a University Hospital in Beirut

Mental health problems are common in Lebanon, and so are psychiatric emergencies. In order to show the characteristics of psychiatric emergencies in Lebanon along with their dispositional determinants, we conducted this retrospective, single-center, chart-review study of patients who presented to the Emergency Department between July 1, 2016 until December 31, 2016 and required an official psychiatrist consultation. Our sample included 195 patients of all age groups. The most common diagnosis was depression (75 patients) followed by anxiety (61 patients). 107 patients (54.8%) required admission for adequate treatment; however only 72 (67.3%) of those were actually admitted, and the rest (32.7%) left the hospital against medical advice. Increased hospital admission was associated with being a female (OR = 3.042), having family history of psychiatric disease (OR = 2.040) and having suicidal ideations (OR = 12.949). In a country that has inadequate health coverage, financial coverage can also be a determining factor in whether or not patients get the admission they need.

Effects of ginger supplementation on cell-cycle biomarkers in the normal-appearing colonic mucosa of patients at increased risk for colorectal cancer: results from a pilot, randomized, and controlled trial

To estimate the effects of ginger on apoptosis, proliferation, and differentiation in the normal-appearing colonic mucosa, we randomized 20 people at increased risk for colorectal cancer to 2.0 g of ginger or placebo daily for 28 days in a pilot trial. Overall expression and distributions of Bax, Bcl-2, p21, hTERT, and MIB-1 (Ki-67) in colorectal crypts in rectal mucosa biopsies were measured using automated immunohistochemistry and quantitative image analysis. Relative to placebo, Bax expression in the ginger group decreased 15.6% (P = 0.78) in the whole crypts, 6.6% (P = 0.95) in the upper 40% (differentiation zone) of crypts, and 21.7% (P = 0.67) in the lower 60% (proliferative zone) of crypts; however, there was a 19% increase (P = 0.14) in Bax expression in the upper 40% relative to the whole crypt. While p21 and Bcl-2 expression remained relatively unchanged, hTERT expression in the whole crypts decreased by 41.2% (P = 0.05); the estimated treatment effect on hTERT expression was larger in the upper 40% of crypts (-47.9%; P = 0.04). In the ginger group, MIB-1 expression decreased in the whole crypts, upper 40% of crypts, and lower 60% of crypts by 16.9% (P = 0.39), 46.8% (P = 0.39), and 15.3% (P = 0.41), respectively. These pilot study results suggest that ginger may reduce proliferation in the normal-appearing colorectal epithelium and increase apoptosis and differentiation relative to proliferation--especially in the differentiation zone of the crypts and support a larger study to further investigate these results.

[Role of psychosocial stress in complex diseases]

Complex diseases are chronic diseases where the interrelations between genetic predisposition and environmental factors play an essential role in the arisen and the maintenance of the pathology. Upon psychological stress, the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system are activated resulting in release of glucocorticoids and catecholamines. Chronic stress may induce complex diseases where alterations of nervous, endocrine and immune systems are involved. Thus, chronic stress is more likely to induce a range of effects, depending on the capacity of the subject to cope with stress. CRH ("Corticotropin Releasing Hormone") is a key factor in the stress-immunity relationship. In this article, we propose an overview of the interrelations between central nervous, endocrine and immune systems and implications for health and diseases. The objective for the clinician is to propose therapeutic strategies targeting changes in human behaviour to cope with a potentially stressful environment.

Notions of synergy for combinations of interventions against infectious diseases in heterogeneously mixing populations

In public health programmes interventions are frequently combined with hoped for 'synergies'[22]. However, there is not yet a precise definition for synergy between interventions that captures the idea that there is added benefit at the population-level in using them together. To explore the synergy between interventions in the context of endemic disease, we consider a general model of infection spread in a heterogeneously mixing population. We consider interventions which may alter individuals' infectiousness, susceptibility, profile of infectiousness through time and survival while infected. Allowing general patterns of overlap and targeting in those receiving the interventions, we show how to compute changes to epidemiological indices such as R(0), and introduce a simple technique for calculating equilibrium prevalences and incidences via an iterated map. We argue for a particular definition of synergy and investigate its behaviour, both analytically and numerically, concluding that it is easiest to achieve synergy between interventions which perform poorly in isolation; implementation strategies that minimize the overlap of different interventions in the population tend to achieve more synergy; and that in populations with heterogeneous risk, interventions that are redundant when universally targeted can regain substantial synergy when applied in a targeted manner.

Sex influences the susceptibility to reperfusion-induced sustained ventricular tachycardia and β-adrenergic receptor blockade in conscious rats

Reperfusion after a brief period of cardiac ischemia can lead to potentially lethal arrhythmias. Importantly, there are sex-related differences in cardiac physiology and in the types and severity of cardiac arrhythmias. Therefore, we tested the hypothesis that gonadal hormones influence the susceptibility to reperfusion-induced sustained ventricular tachycardia (VT), as well as the response to β-adrenergic receptor blockade. Male and female intact and gonadectomized rats were instrumented, and arterial pressure, temperature, ECG, and cardiac output were recorded. In addition, a snare was placed around the left main coronary artery. Tension was applied to the snare for determination of susceptibility to sustained VT produced by 3 min of occlusion and reperfusion of the left main coronary artery in conscious rats. Reperfusion culminated in sustained VT in 77% (10 of 13 susceptible) of female rats and 56% (9 of 16 susceptible) of male rats ( P > 0.05, male vs. female). β-Adrenergic receptor blockade prevented sustained VT in females only [1 of 9 susceptible females (11%) vs. 6 of 9 susceptible males (67%), P < 0.05]. Ovariectomy did not significantly reduce the susceptibility to reperfusion arrhythmias [5 of 9 susceptible (56%)]. In sharp contrast, orchidectomy significantly increased the susceptibility to reperfusion arrhythmias [9 of 9 susceptible (100%)]. Finally, β-adrenergic receptor blockade prevented sustained VT in ovariectomized females [0 of 4 susceptible (0%)] and orchidectomized males [0 of 7 susceptible (0%)], but the protective effect of β-blockade was due to a reduction in heart rate in males only. Thus gonadal hormones influence the susceptibility to reperfusion-induced arrhythmias, as well as the effects and mechanisms of β-adrenergic receptor blockade.

Exercise training normalizes beta-adrenoceptor expression in dogs susceptible to ventricular fibrillation

Previous studies demonstrated an enhanced beta(2)-adrenoceptor (AR) responsiveness in animals susceptible to ventricular fibrillation (VF) that was eliminated by exercise training. The present study investigated the effects of endurance exercise training on beta(1)-AR and beta(2)-AR expression in dogs susceptible to VF. Myocardial ischemia was induced by a 2-min occlusion of the left circumflex artery during the last minute of exercise in dogs with healed infarctions: 20 had VF [susceptible (S)] and 13 did not [resistant (R)]. These dogs were randomly assigned to either 10-wk exercise training [treadmill running; n = 9 (S) or 8 (R)] or an equivalent sedentary period [n = 11 (S) or 5 (R)]. Left ventricular tissue beta-AR protein and mRNA were quantified by Western blot analysis and RT-PCR, respectively. Because beta(2)-ARs are located in caveolae, caveolin-3 was also quantified. beta(1)-AR gene expression decreased ( approximately 5-fold), beta(2)-AR gene expression was not changed, and the ratio of beta(2)-AR to beta(1)-AR gene expression was significantly increased in susceptible compared with resistant dogs. beta(1)-AR protein decreased ( approximately 50%) and beta(2)-AR protein increased (400%) in noncaveolar fractions of the cell membrane in susceptible dogs. Exercise training returned beta(1)-AR gene expression to levels seen in resistant animals but did not alter beta(2)-AR protein levels in susceptible dogs. These data suggest that beta(1)-AR gene expression was decreased in susceptible dogs compared with resistant dogs and, further, that exercise training improves beta(1)-AR gene expression, thereby restoring a more normal beta-AR balance.

The nuclear factor-kappaB (NF-kappaB): from a versatile transcription factor to a ubiquitous therapeutic target

The nuclear factor-kappaB (NF-kappaB) transcription factors regulate a plethora of cellular pathways and processes including the immune response, inflammation, proliferation, apoptosis and calcium homeostasis. In addition to the complexity of its physiological roles, the composition and function of this family of proteins is very complicated. While the basic understanding of NF-kappaB signalling is extensive, relatively little is know of the in vivo dynamics of this pathway or what controls the balance between various outcomes. Although we know a large number of NF-kappaB-responsive genes, the contribution of these genes to a specific response is not always clear. Finally, the involvement of NF-kappaB in pathological processes is only now beginning to be unravelled. In addition to cancer and immunodeficiency disorders, altered regulation of NF-kappaB has been associated with several inherited diseases. These findings indicate that modulation of the NF-kappaB pathways may be beneficial. However, our limited knowledge of NF-kappaB signalling hinders therapeutic approaches: in many situations it is not clear whether the enhancement or inhibition of NF-kappaB activity would be beneficial or which pathways to interfere with and what the required level of activation is. Further studies of the role of NF-kappaB are needed as these may result in novel therapeutic strategies for a wide variety of diseases.

Mechanisms of immune evasion by tumors

In the past decade, basic studies in animal models have begun to elucidate the physiological barriers which impede a successful antitumor immune response. These barriers operate at a number of levels, and involve the tumor, the tumor microenvironment and various components of the innate and adaptive immune systems. In this review, we discuss the multiple mechanisms by which tumors evade an immune response, with an emphasis on clinically relevant strategies to overcome these inhibitory checkpoints.

α-Lipoic acid prevents diabetes mellitus in diabetes-prone obese rats

Several lines of evidence have suggested that triglyceride accumulation in skeletal muscle and pancreatic islets is causally related to type 2 diabetes mellitus. We recently showed that alpha-lipoic acid (ALA), a potent antioxidant and cofactor of mitochondrial respiratory enzymes, reduces body weight of rodents by suppressing food intake and increasing energy expenditure. We sought to determine if ALA can prevent the development of diabetes mellitus in obese Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Most (78%) untreated OLETF rats showed glycosuria at 40 weeks of age, but this was completely prevented by ALA. Compared with untreated OLETF rats, ALA reduced body weight and protected pancreatic beta-cells from destruction. ALA also reduced triglyceride accumulation in skeletal muscle and pancreatic islets. These results indicate that ALA prevents diabetes mellitus in obese diabetes-prone rats by reducing lipid accumulation in non-adipose tissue as well as in adipose tissue.

Active hexose correlated compound enhances the immune function of mice in the hindlimb-unloading model of spaceflight conditions

Hindlimb unloading is a ground-based model that simulates some of the aspects of spaceflight conditions, including lack of load bearing on hindlimbs and a fluid shift to the head. It has been shown that treatment with active hexose correlated compound (AHCC) restores resistance to infection in mice maintained under hindlimb-unloading conditions. The present study was designed to clarify the mechanisms by which AHCC enhances resistance to infection in this model. We hypothesized that oral administration of AHCC will enhance the function of the immune system, which could lead to the increased resistance to infection observed in this model. AHCC or the excipient was orally administered to mice, and the function of the immune system was assessed in spleen and peritoneal cells isolated from those groups. The results of the present study showed that administration of AHCC for 1 wk before and throughout the second day of the hindlimb-unloading period enhanced the function of the immune system assessed by spleen cell proliferation and cytokine production in spleens and nitric oxide and cytokine production in peritoneal cells. These findings suggest that AHCC can be used as a potent immunoenhancer, especially in cases in which the immune system is suppressed by any condition, including diseases such as human immunodeficiency virus infection and cancer.

Presence of IgE antibodies to bacterial superantigens and increased IL-13-producing T cells in myelitic patients with atopic diathesis

BACKGROUND

Superantigens are considered to exacerbate autoimmune inflammation through the expansion of autoreactive T cells; however, the immune response to bacterial superantigens has not been extensively studied in any type of myelitis. We recently reported the occurrence of a distinct type of myelitis in patients with atopic diathesis, which in a recent nationwide survey was reported to be widespread in Japan. The aim of this study was to investigate the presence of IgE antibodies to bacterial superantigens and the proportion of IL-13- or IL-5-producing CD4+ or CD8+ T cells in patients with myelitis and atopic diathesis.

METHODS

Twenty-four myelitic patients with and 12 myelitic patients without hyperIgEemia, 28 patients with multiple sclerosis (MS) and 34 healthy controls were enrolled in this study. IgE antibodies to staphylococcal enterotoxins A (SEA) and B (SEB) in sera were measured using a liquid-phase enzyme immunoassay, and the intracellular production of IL-5 and IL-13 in peripheral blood CD4+ and CD8+ T cells was measured by flow cytometry.

RESULTS

The myelitic patients with hyperIgEemia showed significantly higher positive rates of serum SEA/SEB-specific IgE antibodies (41.7 and 62.5%, respectively) than the healthy controls (5.9 and 8.8%), patients with MS (0 and 21.4%) and those with normoIgEemic myelitis (0 and 0%). Moreover, IL-13-producing CD4+ T cells and CD8+ T cells increased significantly in the myelitic patients with hyperIgEemia compared to the controls, while IL-5-producing CD4+ or CD8+ T cells did not.

CONCLUSIONS

The IgE response to staphylococcal superantigens is heightened in myelitic patients with atopic diathesis, which might contribute to increases in IL-13-producing T cells and thus the development of myelitis.

Schizophrenia and eye movement – a new diagnostic and therapeutic concept

In the present article, conclusions are drawn from four papers on the genesis of schizophrenia, published in Medical Hypotheses between 1999 and 2002, knowledge of which is required to understand this paper in greater depth. For these, the author had developed two sight tests in which schizophrenic patients revealed a stronger fusional reactivity of the nasal than of the temporal foveal halves and a disconnection between peripheral and foveal vision. Both phenomena could be explained by a reversed crossing of foveal projections in the chiasma opticum constituting a genetic vulnerability which, in case of additional defects of binocular balance, could result in a foveal convergence stimulus being executed as a divergence movement by one of the eyes. The author has now succeeded in finding a very simple standardized method to discover the described vergence abnormality, the Hook test, part of the ZEISS Near Pola Test, which would therefore be suitable for detecting schizophrenic vulnerability in screening tests so that the outbreak of schizophrenia could be prevented by an early correction of the additional visual defects. The movement impulses resulting from the erraneous vergence are analyzed and explain the phenomenon of the schizophrenic's "mad look". The connection between the somatic component and the patient's psycho-social problems is shown and a detailed description given of non-neuroleptic methods of rectifying both.

ACE inhibition may decrease diabetes risk by boosting the impact of bradykinin on adipocytes

The findings of the recent HOPE trial strongly suggest that ACE inhibitor therapy may reduce risk for type 2 diabetes in patients who are non-diabetic at baseline. This finding is readily rationalized by previous evidence that bradykinin, acting via B2 receptors, can potentiate the insulin responsiveness of both adipocytes and muscle fibers; this effect may be mediated by a reduction in the activity of a tyrosine phosphatase that targets the insulin receptor. ACE inhibitors, in turn, increase the availability of bradykinin by suppressing its proteolytic degradation. In light of the fact that the development of insulin resistance in adipocytes is responsible for the excessive free fatty acid flux that gives rise to the diabetic syndrome, a favorable impact of ACE inhibition on adipocyte insulin responsiveness - complemented by a potentiation of the direct action of bradykinin on skeletal muscle - offers a satisfying explanation for the prevention of diabetes observed during ACE inhibitor therapy. Since the population at risk for diabetes is huge and increasing dramatically, the recent development of orally absorbable food-derived peptides with clinically significant ACE inhibitory activity - such as 'Katsuobushi oligopeptides' derived from bonito - may make it more logistically feasible to achieve this protection on a widescale basis, while simultaneously promoting blood pressure control and reducing risk for atherothrombotic disease.

Susceptibility of ascending dopamine projections to 6-hydroxydopamine in rats: effect of hypothermia

The aims of this study were to determine (1) whether mesolimbic and nigrostriatal DA cell bodies degenerate to different extents after 6-hydroxydopamine (6-OHDA) is administered into their respective terminal fields and (2) whether hypothermia, associated with sodium pentobarbital anesthesia, protects DA neurons from the toxic effects of 6-OHDA. To address these questions, 6-OHDA or vehicle was infused into either the ventral or dorsal striatum or into the medial forebrain bundle, under conditions of brain normothermia or hypothermia. Two weeks post-surgery, tyrosine hydroxylase-positive cell bodies were counted in the ventral tegmental area (VTA) and substantia nigra. In addition, autoradiographic labeling of tyrosine hydroxylase protein and dopamine transporter was quantified in dopamine terminal fields and cell body areas. Overall, DA cell bodies in the VTA were substantially less susceptible than those in the substantia nigra to depletion of dopaminergic markers. Hypothermia provided two types of neuroprotection. The first occurred when 6-OHDA was administered into the dorsal striatum, and was associated with a 30-50% increase in residual dopaminergic markers in the lateral portion of the VTA. The second neuroprotective effect of hypothermia occurred when 6-OHDA was given into the medial forebrain bundle. This was associated with a 200-300% increase in residual dopaminergic markers in the mesolimbic and nigrostriatal terminal fields; no significant protection occurred in the cell body regions.Collectively, these findings show that (1) the dopaminergic somata in the substantia nigra are more susceptible than those in the VTA to 6-OHDA-induced denervation, and (2) hypothermia can provide anatomically selective neuroprotection within the substantia nigra-VTA cell population. The continued survival of mesolimbic dopamine cell bodies after a 6-OHDA lesion may have functional implications relating to drugs of abuse, as somatodendritic release of dopamine in the VTA has been shown to play a role in the effectiveness of cocaine reward.

Microbiology of choledochal bile in patients with choledocholithiasis admitted to a tertiary hospital

AIM

The present study was designed to investigate the microbiology of choledochal bile of patients with cholangitis and choledocholithiasis.

METHODS

We identified and determined the antimicrobial susceptibility of bacteria isolated in the bile of patients with cholangitis and choledocholithiasis diagnosed by endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

Nineteen (82.6%) of 23 patients with choledocholithiasis had positive bile cultures. A single agent was detected in 11 patients (57.9%), while a mixed growth, with pathogens ranging from two to three species, were seen in eight patients (42.1%). Patients with clinical manifestations of cholangitis had significantly higher counts of colonies per mL of bile (> 105 cfu/mL). The predominant Gram-negative aerobic bacteria isolated were Escherichia coli (9, 31.0%), Klebsiella pneumoniae (5, 17.2%), Enterobacter cloacae (2, 6.9%), Pantoea agglomerans (1, 3.4%), and Pseudomonas aeruginosa (1, 3.4%). The predominant Gram-positive bacteria were Enterococcus faecalis (5, 17.2%) and Streptococcus sp. (5, 17.2%). Bacteroides fragilis was isolated in one patient with mixed growth. All Gram-positive bacteria isolated in bile were sensitive to ampicillin, and all Gram-negative bacteria isolated were sensitive to gentamicin with a minimum inhibitory concentration (CIM90) ranging from 0.5 to 1.0- micro g/mL. Gram-negative bacteria were also sensitive to imipenem, fluorquinolones, second and third generation cephalosporins. Although all five isolates of E. faecalis were sensitive to ampicillin, two of five (40%) E. faecalis isolates demonstrated high levels of resistance to gentamicin.

CONCLUSION

E. coli, K. pneumoniae, E. faecalis and Streptoccocus sp. were the most common bacteria isolated in the bile of patients with cholangitis and choledocholithiasis, which were sensitive to a simple therapeutic regimen, such as the combination of ampicilin and gentamicin.

Hyperbaric oxygen increases the lung's susceptibility to inhaled lipopolysaccharide in mice

Hyperbaric oxygen (HBO2) has been shown to inhibit the adhesion function of beta(2)-integrin, which is important in mediating cell-to-cell adhesion and extravasation of inflammatory cells. In the present study, we examined the effects of HBO2 exposure on neutrophil infiltration and tissue injury in a model of acute lung inflammation induced by lipopolysaccharide (LPS) inhalation. Male C57BL/6 mice of 8 weeks old were exposed to 3 atmosphere absolute (ATA) 100% HBO2, 3 ATA hyperbaric air (HBA), or room air for 90 min. After exposure, they were exposed to aerosolized LPS solution (1 mg/ml) or saline in a plexiglass chamber for 10 min. Four hours after inhalation, bronchoalveolar lavage (BAL) was performed to determine protein concentration, LDH activity, total cells, and differential cell counts in the lavage fluid (BALF). Myeloperoxidase (MPO) content, lung histopathology, and plasma nitric oxide (NO) metabolite concentrations were also determined in separate sets of animals. We observed that LPS inhalation increased neutrophil number in the BALF, which was significantly inhibited by HBO2 but not HBA pre-exposure. However, MPO content in the lung was prominently increased by HBO2 pre-exposure, which correlated with increased PMN infiltration in lung tissues. Further, HBO2 plus LPS, but not saline inhalation caused a significant increase in the BALF protein level and LDH activity compared with that of LPS inhalation alone. LPS exposure induced significant increase in plasma NO metabolites, which was not potentiated by HBO2 pre-exposure. The inducible nitric oxide synthase inhibitor, aminoguanidine, significantly attenuated the increases in plasma NO metabolites and tissue MPO content as well as lung injuries. In summary, our data suggest that HBO2 pre-exposure increases the lung's susceptibility to inhaled LPS, which may be related to increased tissue neutrophil infiltration and dependent on interaction(s) between HBO2 exposure with LPS-induced nitric oxide production.

[Balneotherapy, health care and public health]

The actual interest of Spa-therapy in public health is considered as a way of improving health, well-being state or as prevention or treatment of different diseases. The various definitions of health are exposed and its possible influence in human beings, and in particular the complexity of the Spa-therapy. The possible positive effects of the Spa-therapy have been tested in the official Centers of several countries and have been considered of great value in Health Education its signification as a primary, secondary and tertiary health agent.

Detection, education and management of the asplenic or hyposplenic patient

Fulminant, potentially life-threatening infection is a major long-term risk after splenectomy or in persons who are functionally hyposplenic as a result of various systemic conditions. Most of these infections are caused by encapsulated organisms such as pneumococci, Haemophilus influenzae and meningococci. A splenectomized patient is also more susceptible to infections with intraerythrocytic organisms such as Babesia microti and those that seldom affect healthy people, such as Capnocytophaga canimorsus. Most patients who have lost their spleens because of trauma are aware of their asplenic condition, but some older patients do not know that they are asplenic. Other patients may have functional hyposplenism secondary to a variety of systemic diseases ranging from celiac disease to hemoglobinopathies. The identification of Howell-Jolly bodies on peripheral blood film is an important clue to the diagnosis of asplenia or hyposplenia. Management of patients with these conditions includes a combination of immunization, antibiotic prophylaxis and patient education. With the increasing prevalence of antibiotic-resistant pneumococci, appropriate use of the pneumococcal vaccine has become especially important.

[Gene therapy--hopes and fears]

Gene therapy assumes the correction of a genetic defect by the delivery of a correct DNA sequence to the target cells. Depending on the target cells two types gene therapy have been defined: somatic and germinal. By July 1998, 351 protocols of somatic therapy were approved by the Recombinant DNA Advisory Committee. The majority of protocols focus on cancer therapy and monogenic diseases. By now, still there is more unfulfilled expectation than clinically sound achievements, since no effective prevention or successful treatment for genetic diseases or cancer have been developed. Germline genetic modification is considered as the treatment of choice for such a diseases like retinoblastoma. Tay-Sachs, Lesch-Nyhan and metachromatic leuko-dystrophy. This approach which is still illegal or prohibited by rules in many European countries, is gathering more and more advocates. Once we learn how to control gene expression the perspectives for clinical application of gene therapy might be enormous. The safety of genetic modification of gametes or embryonal stem cells remains to be properly addressed and successfully solved. The ethical issues of germinal gene therapy are still the subject of controversial opinions among the scientists, lawyers and philosophers.

Diet, androgens, oxidative stress and prostate cancer susceptibility

Prostate cancer is the most common human malignancy and the second leading cause of cancer deaths among men in Western nations. Descriptive epidemiologic data suggest that androgens and/or environmental exposures, such as diet (in particular, dietary fat), play an important role in prostatic carcinogenesis. One plausible link between diet and prostate cancer is oxidative stress. This process refers to the generation of reactive oxygen species, which can then trigger a host of pro-carcinogenic processes. Recent studies also indicate that androgens increase oxidative stress within human prostate cancer cell lines. Recent data from our institution indicate that oxidative stress is higher within the benign epithelium of prostate cancer patients than men without the disease. This confirms our hypothesis and suggests that antioxidants such as lycopene, vitamin E, and selenium may play an important role in preventing disease progression. Large-scale clinical trials with some of these agents are currently in the design phase.

Stool cultures obtained before liver transplantation are useful for choice of perioperative antibiotic prophylaxis

Bacterial infections, especially cholangitis, are still common complications after liver transplantation (LTx). During recent years, multiresistant enterococci have become a nosocomial problem in transplant units. The present prospective study on 26 patients, including 24 patients with chronic liver disease, demonstrated that enterococci were the predominant micro-organism involved in post-LTx bacterial infections. They were cultured in the feces and in other sites of 10 out of 13 (77%) patients who underwent extensive examinations. Ampicillin-resistant Enterococcus faecium strains were isolated in urine or feces of 2 of the 13 patients prior to LTx. Similarly, resistance to ampicillin and gentamicin, the empirically used antibiotics for patients with fever of unknown origin, was found in E. faecium strains in 3 and 2 patients, respectively. Moreover, multiresistant E. faecium and E. faecalis strains were demonstrated in 46% of the patients in the postoperative period (3 months). However, no vancomycin-resistant enterococci were isolated. The use of antibiotics within 4 months prior to LTx significantly increased the risk of developing ampicillin-resistant bacteria at the time of LTx and of infections with bacteria of enteric origin after LTx (P = 0.03 and 0.01, respectively). We conclude that stool and urine cultures performed prior to LTX may be useful for selecting prophylactic antibiotic regimens.

Early detection and intervention in schizophrenia: editor's introduction

A greater understanding of the nature of schizophrenia, along with the continuing limitations of our current treatments, has refocused attention on the early course of psychosis in the form of early detection and intervention around onset. This issue of the Bulletin offers an indepth look at the knowledge, models, current data, and seminal clinical research programs that support why renewed interest in the late premorbid, prodromal, and onset phases of schizophrenia appears both timely and reasonable.

Class II antigens and disease susceptibility

The role for HLA typing in autoimmune disease is changing with the recognition that HLA markers can identify patients with poor prognosis in some autoimmune disease. Aggressive therapeutic intervention in patients with such HLA prognostic markers has the potential to improve or prevent progressive disease outcomes in a select group of patients.

Primary malignant lymphoma of the liver

Clinical and pathologic features of 69 cases with primary hepatic lymphoma, 52 reported from Western countries and 17 cases from Japan, were summarized in terms of clinical findings including age and sex, past history, presenting symptoms, and physical findings, diagnostic procedures including imaging techniques and histopathology, and finally therapy and follow-up. The present cases included four patients with an acquired immunodeficiency syndrome and 12 with a history of chronic liver diseases. Histologically, all cases were non-Hodgkin's lymphoma with diffuse large cell type being the most common immunochemically about 80% were B-cell type. Follow-up showed that hepatic lymphoma had a relatively favourable prognosis provided early detection was possible.