Disposable laryngoscope blades do not interfere with ease of intubation in scheduled general anaesthesia patients

BACKGROUND AND OBJECTIVE

Intubation of the trachea has been a risky cross-contamination procedure over the past decade because no perfect decontamination procedures exist. Infectious agents found on laryngoscopic devices have the potential for devastating spread of the human immunodeficiency virus, hepatitis viruses B and C and transmissible non-conventional agents. The purpose of this prospective observational study was to assess the quality of endotracheal intubation with disposable laryngoscope blades, under normal intubating conditions.

METHODS

Anaesthetists were asked to complete daily questionnaires regarding the difficulty of intubation experienced using the Vital View disposable laryngoscope blade (Vital Signs Inc, Totowa, NC, USA). The choice of the type of blade (conventional or disposable blade) for the first attempt at intubation depended only on the operating room assignment. Glottic visualization during laryngoscopy was assessed by the modified Cormack and Lehane classification. Difficult tracheal intubation was evaluated by the intubation difficulty scale (> 5, procedure involving moderate to major difficulty).

RESULTS

The anaesthetic staff recorded 219 intubations. One hundred-and-nineteen of first attempts at laryngoscopy were with disposable blades (DB group) and another 100 with conventional blades (CB group). There were no significant differences between the two groups for Cormack and Lehane score 3, for intubation difficulty scale scores > 5 and for intubation difficulty scale score 0. There were 12 blade changes before successful intubation.

CONCLUSIONS

In routine use, the Vital View disposable laryngoscope blade appears to be an efficient device because it does not modify the ease of endotracheal intubation in most cases. Nonetheless, it may be advisable to maintain conventional laryngoscopes in reserve for difficult intubations.

Effects of dietary supplementation with isoflavones from red clover on ambulatory blood pressure and endothelial function in postmenopausal type 2 diabetes

OBJECTIVE

The aim of this study was to determine whether dietary supplementation with isoflavones from red clover affected ambulatory blood pressure and forearm vascular endothelial function in postmenopausal type 2 diabetic women.

DESIGN

Sixteen postmenopausal type 2 diabetics treated with diet or oral hypoglycaemic therapy completed a randomized double-blind crossover trial of dietary supplementation with isoflavones from red clover (approximately 50 mg/day) for 4 weeks compared to placebo. Twenty-four-hour ambulatory blood pressure recordings and forearm vascular responses to acetylcholine, nitroprusside and L-nitromonomethylarginine (L-NMMA) were measured at the end of each treatment period.

RESULTS

Mean daytime systolic and diastolic blood pressures were significantly lower during isoflavone therapy compared to placebo (-8.0 +/- 3.4 and -4.3 +/- 1.9 mmHg respectively, p < 0.05). The increase in forearm vascular resistance following L-NMMA was significantly greater during isoflavone supplementation (20.9 +/- 6.5) than placebo (3.7 +/- 2.9 arbitrary units, p < 0.05), suggesting an improvement in basal endothelial function. Plasma lipoproteins, glycated haemoglobin and forearm vascular responses to acetylcholine and nitroprusside did not differ significantly between isoflavone and placebo therapy.

CONCLUSION

Isoflavone supplementation from red clover may favourably influence blood pressure and endothelial function in postmenopausal type 2 diabetic women.

[Clopidogrel and thrombopenia. A case report]

We report our experience with a case of isolated profound thrombocytopenia after clopidogrel (thienopyridine) administration. No adverse event such as bleeding or thrombotic event had occurred, although clopidogrel has been discontinued two weeks after the coronary artery stenting. Despite the safety of clopidogrel, this case demonstrates that clopidogrel can be associated not only with thrombotic thrombocytopenic purpura but also with isolated thrombocytopenia.

Pharmacokinetic profile of a modified release formulation of trimetazidine (TMZ MR 35 mg) in the elderly and patients with renal failure

Objectives - To study the effect of age and renal function on the pharmacokinetic profile of a modified release tablet of trimetazidine (TMZ MR 35 mg) administered twice daily.Methods- Study 1: Twelve healthy elderly subjects (CL(creat) 72+/-8 ml/min, 72+/-4 years mean+/-SD) and eight young volunteers (CL(creat) 134+/-18 ml/min, 25+/-8 years) received TMZ MR 35 mg b.i.d. (eight doses). Study 2: eight patients with severe renal failure (CL(creat.) 17+/-5 ml/min, 54+/-10 years), five patients with moderate renal failure (CL(creat.) 39+/-6 ml/min, 54+/-15 years) and eight volunteers (CL(creat.) 104+/-17 ml/min, 53+/-9 years) received TMZ MR 35 mg b.i.d. (patients: ten doses, volunteers: eight doses). Serial blood and urine samples were obtained following administration of the last dose in each study. TMZ plasma and urine concentrations were determined by gas chromatography (NPD-detector). The resulting data were analysed using standard non-compartmental pharmacokinetic methods.Results- Study 1: Elimination half-life of TMZ was significantly longer and renal clearance significantly lower in the elderly subjects. Study 2: In patients with either moderate or severe renal failure, exposure (AUC(0-24)) was significantly increased and renal clearance (CL(R)) was significantly decreased. Significant correlations were observed between CL(creat) and CL(R) (r=0.94) and between CL(creat) and AUC(0-24) (r=-0.94). Conclusion - With repeated administration of TMZ MR 35 mg b.i.d., a decrease in CL(creat) is directly related to a decrease in CL(R) and results in an increase in exposure to TMZ.

Cutaneous melioidosis

Melioidosis is a rare tropical disease caused by infection with the bacterium Burkholderia pseudomallei. It occurs predominantly in south-east Asia, northern and central Australia and central and south America. Patients often present to the internal medicine physicians with a severe, potentially fatal sepsis. We report three patients who presented to our dermatology department with cutaneous melioidosis.

Cutaneous melioidosis

Melioidosis is a rare tropical disease caused by infection with the bacterium Burkholderia pseudomallei. It occurs predominantly in south-east Asia, northern and central Australia and central and south America. Patients often present to the internal medicine physicians with a severe, potentially fatal sepsis. We report three patients who presented to our dermatology department with cutaneous melioidosis.

Laboratory evaluation of mouthguard material

The aim of this study was to evaluate, in vitro, the EVA material (polyvinylacetate-polyethylene copolymer) most commonly used in the fabrication of mouthguards and thus to help understand mouthguard performance and to improve mouthguard design. The material was tested for tensile strength, elongation, hardness and water absorption using specimens and tests described by the American Society for Testing and Materials Standards. Standard EVA sheets of 1, 2, 3 and 5 mm thickness were prepared. With increase in the thickness of the material, both the ultimate tensile strength and the elongation were decreased. The hardness and water absorption were unaffected. It was concluded that. overall, the thicker 5 mm EVA material was recommended for mouthguards as it displayed the least deformation to load and performed equally as well in the tests as other thicknesses.

How water oxygenation level influences cadmium accumulation pattern in the Asiatic clam Corbicula fluminea: a laboratory and field study

The level of O2 in water is highly variable in the aquatic environment and is a major ventilatory drive in all animals breathing water. Low O2 partial pressure (PO2) strongly stimulates ventilatory activity compared to air-equilibrated or O2-enriched water. We studied the influence of ventilatory activity on the bioaccumulation rate of Cd in the freshwater Asiatic clam Corbicula fluminea for PO2 ranging from 4 to 40 kPa (2-20 mg/L at 15 degrees C) during steady-state exposure to controlled concentrations of Cd of approximately 2 or 0.5 microg/L under both laboratory and field conditions. The concentration of Cd in the expired water and its apparent extraction coefficient (EwCd) from the ventilated water were calculated. Results show that a low PO2 strongly enhanced Cd bioaccumulation rate in the whole soft body and modified the distribution pattern and the relative burden in the organs. Whatever the water PO2, values for the concentration of Cd in the expired water remained close to the Cd concentration in the inspired water and EwCd varied from 2 to 12%. Because the field results conformed to the laboratory analysis, the suggestion is made that the influence of O2 on bioaccumulation patterns of metals in water-breathers should be classified as of primary importance.

The effects of candesartan on vascular responses to angiotensin II and norepinephrine in normal volunteers

The effects of chronic administration of candesartan, 16 mg once-daily, to normal volunteers on cardiovascular responses to angiotensin II (Ang II) and norepinephrine (NE) were examined. Fifteen healthy, non-smoking volunteers participated in a randomised, double-blind crossover study of two weeks of candesartan therapy, compared with two weeks of placebo. Blood pressure (BP) responses were measured to increasing infusion rates of intravenous Ang II and NE, along with forearm blood flow (FBF) responses into intra-brachial arterial Ang II, 2 and 24 hours after the last dose of candesartan or placebo. FBF responses to intra-brachial arterial NE were recorded approximately 2 hours following the final dose. Systolic and diastolic BP responses to intravenous infusions of Ang II during candesartan treatment were completely suppressed and significantly lower than during placebo treatment, 2 hours (candesartan 96+/-10/55+/-8 mmHg; placebo 105+/-5/64+/-8 mmHg) and 24 hours (candesartan 94+/-8/54+/-8 mmHg; placebo 103+/-7/64+/-7 mmHg) following the last dose. In contrast, FBF responses to intra-brachial arterial Ang II were significantly suppressed by candesartan compared with placebo in a subgroup of subjects 2 hours following the last dose (n=9), but not 24 hours after the last dose (n=8). FBF responses to NE were also suppressed by candesartan treatment 2 hours following the last dose, while BP responses to intravenous NE were unaltered. Chronic candesartan therapy, 16 mg once-daily effectively suppresses pressor responses to Ang II over the duration of the dosing interval.

Expression of apoptosis-related proteins and structural features of cell death in explanted aortocoronary saphenous vein bypass grafts

This study aimed to investigate the features of cell death occurring in aortocoronary saphenous vein bypass grafts. Human aortocoronary saphenous vein bypass grafts with angiographic luminal stenosis of > 75% were explanted from 14 patients at redo coronary artery bypass grafting. Proteins associated with apoptotic pathways were identified immunohistochemically using antibodies to Bcl-2, Fas, BAX, p53 and CPP32. Cells undergoing DNA fragmentation were identified by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). DNA synthesis was investigated using the antibody to proliferating cell nuclear antigen (PCNA). Ultrastructural features of cell death were examined by electron microscopy. Anti-apoptotic (Bcl-2) and pro-apoptotic (Bax, p53, CPP32 and Fas) proteins were expressed throughout the graft wall, but marked differences in the characteristics of cell death were noted between atherosclerotic and non-atherosclerotic areas of the intima. In atherosclerotic areas, pro-apoptotic proteins were widely expressed, but ultrastructural analysis failed to identify cells showing typical features of apoptosis. In these areas, necrotic cells were frequently observed, with negative correlation of Bcl-2 expression with TUNEL. Pro-apoptotic proteins showed no correlation with TUNEL. In contrast, in non-atherosclerotic areas of vein grafts, the expression of both anti-apoptotic (Bcl-2) and pro-apoptotic proteins (p53, Bax and CPP32) correlated with TUNEL. In atherosclerotic areas, non-atherosclerotic intimal areas, and in the underlying media, the numbers of TUNEL+ cells correlated with PCNA positivity. Ultrastructurally, apoptotic bodies and features of necrosis were observed in non-atherosclerotic areas of grafts. The present observations indicate that in atherosclerotic areas, cell death occurs mainly by necrosis, while in non-atherosclerotic areas, cell death occurs by both necrosis and apoptosis. An imbalance between DNA fragmentation and DNA synthesis may contribute to graft instability and failure.

A retrospective review of PUVA therapy at the National Skin Centre of Singapore

BACKGROUND

Photochemotherapy (PUVA) is beneficial for the treatment of various dermatoses. The introduction of ultraviolet B and narrow-band ultraviolet B phototherapy has had a significant impact on the role of PUVA in dermatology. This study aims to assess the current role of PUVA in treating dermatoses, in a predominantly Asian population, at the National Skin Centre in Singapore.

MATERIALS AND METHODS

We reviewed the clinical data of 115 patients who were started on PUVA treatment at the National Skin Centre, Singapore in 1998. We analysed the epidemiology data, the clinical response rate and the adverse effects of PUVA therapy. All of the patients continued to have ongoing maintenance treatment.

RESULTS

Most of our patients were Chinese (74.8%) and male (58.3%), ranging from the ages of 4 to 74 years. Vitiligo (60.9%) was the commonest skin disorder treated with PUVA, followed by psoriasis (20.9%), endogenous eczema (11.3%), mycosis fungoides (3.5%), lichen amyloidosis (2.6%) and prurigo nodularis (0.9%). Most of our patients received paint PUVA (50.4%), 33.9% oral PUVA and 15.7% bath PUVA. The best clinical response--those patients achieving a greater that 50% clearance--was observed in patients with endogenous eczema, psoriasis and mycosis fungoides (76.8%, 73.9% and 60%, respectively). Of the vitiliginous patients, 54.3% experienced a poor response to PUVA therapy. The main side effects were mild erythema and pruritus.

CONCLUSION

PUVA remains a valuable, well-tolerated therapeutic option for a variety of dermatoses.

Suggestions for HER-2/neu testing in breast carcinoma, based on a comparison of immunohistochemistry and fluorescence in situ hybridisation

The arrival of Herceptin (Trastuzumab), an antibody against the HER-2 oncogene found in a proportion of breast carcinomas and other carcinomas, has emphasised the need for a standardised technique for demonstrating overexpression of HER-2. We compared the Dako A485 antibody and Dako HercepTest kit (HT) on a series of 122 breast carcinomas. Fluorescence in situ hybridisation (FISH) (Vysis) was performed on all cases with positive or equivocal immunohistochemical results. The Dako A485 showed HER-2 overexpression in 53% of carcinomas, while the HT showed 21% positive (HT 2+ 8%, HT 3+ 13%) and 79% negative (HT 0 67%, HT 1+ 12%). FISH for HER-2 gene amplification on all the HT 1+ and HT 2+ cases was negative, whereas FISH analysis of all HT 3+ cases was positive, with the exception of one case which could not be analysed for technical reasons. When histological subtype was analysed, only grade 3 infiltrating duct carcinomas were FISH-positive, suggesting that histological grading and subtyping may be able to triage carcinomas suitable for HER-2 testing. We suggest that the HT or a similar standardised immunohistochemical study for HER-2 can be used to screen breast carcinomas. We then recommend FISH where the carcinoma is HT 2+. FISH may also be appropriate in high grade, HT 1+ carcinomas where there are doubts regarding optimal tissue fixation or block storage conditions.

Utility of semiquantitative polymerase chain reaction for Epstein-Barr virus to measure virus load in pediatric organ transplant recipients with and without posttransplant lymphoproliferative disease

We examined the utility of Epstein-Barr virus (EBV) load as a test for the presence of posttransplant lymphoproliferative disease (PTLD). A semiquantitative (SQ) EBV polymerase chain reaction (PCR) on peripheral blood mononuclear cells (PBMC) was used to determine virus load. We compared the values from pediatric patients, both with and without PTLD, with those from healthy pediatric and adult subjects. The virus loads for asymptomatic healthy subjects had a range of 0-1 log10 cells/10(6) PBMCs. Among transplant recipients (n=135), the mean virus load (+/- standard deviation) at the time of diagnosis of PTLD was 3.1+/-1.2 log(10) cells/10(6) PBMCs versus a baseline value of 1.3+/-1.4 log(10) cells/10(6) PBMCs in children without PTLD (P<.0001). A cutoff of > or =3 log10 cells/10(6) peripheral blood leukocytes resulted in the following values for use of virus load as a test for PTLD: sensitivity, 69%; specificity, 76%; positive predictive value, 28%; and negative predictive value, 95%. We conclude that determination of EBV load by use of SQ PCR is more useful in ruling out than in indicating the presence of PTLD.

Short-course versus conventional length antimicrobial therapy for uncomplicated lower urinary tract infections in children: a meta-analysis of 1279 patients

OBJECTIVE

The objective was to compare the efficacies of single-dose, short-course (4 days or less), and standard course (5 days or greater) antimicrobial therapy for uncomplicated childhood cystitis.

METHODS

Prospective, randomized, controlled trials comparing 4 days or less of therapy (short courses) with 5 days or more of therapy (conventional therapy) were included if all of the subjects were <18 years of age, the initial infection was documented by urine culture, at least 1 subsequent culture was obtained between 3 and 30 days of enrollment, and some attempt was made to separate upper tract from lower tract infection. Composite differences among treatment groups were compared with a fixed or random effects model, depending on the test for heterogeneity.

RESULTS

Of the 517 citations identified by literature search, 37 were selected for detailed review, and 22 were included in the final meta-analysis. The overall difference in cure rates between short and conventional courses of therapy was significant (6.38%; 95% CI: 1.88% to 10.89%), favoring the conventional course. Similar results were obtained when only studies comparing the same agents in the short and conventional courses were included (7.92%; 95% CI: 2.09% to 13.8%). Short-course amoxicillin was inferior to conventional length course (difference in cure rate, 13%; 95% CI: 4% to 24%); no difference was found between short-course and conventional length courses of trimethoprim-sulfamethoxazole (difference in cure rate, 6.24%; 95% CI = -3.74% to 16.2%).

CONCLUSIONS

We conclude that single-dose amoxicillin is inadequate therapy for uncomplicated cystitis of childhood. Three days of trimethoprim-sulfamethoxazole therapy appears to be as effective as conventional length courses of the drug.

Cerebral cortical blood flow during loss of consciousness induced by gravitational stress in rhesus monkeys

We investigated the influence of +Gz acceleration (head-to-foot inertial forces) onset on cerebral cortical blood flow (CBF) of rhesus monkeys to study the mechanisms underlying +Gz-induced loss of consciousness (G-LOC). CBF was measured through a chronic cranial window by laser-Doppler flowmetry and electrodes in contact with the dura mater were used to detect G-LOC (suppression of the cortical electrical activity). The animals were centrifuged up to +12 Gz with different G-onset rate until G-LOC occurred. G-LOC was preceded by a 2-5 s decrease in CBF. At G-LOC detection, CBF was not related to G-onset rate (mean CBF change: -76 +/- 9% of control value). We conclude that G-LOC results from cerebral ischemia rather than from mechanical stresses applied to the brain.

Serotonin transporter promoter polymorphism is associated with attenuated prolactin response to fenfluramine

Disturbances in central serotonin (5-HT) function may have a role in impulsive aggression in patients with a wide range of psychiatric diagnoses. The underlying mechanism, however, remains unknown. There are several naturally occurring mutations in the 5-HT signaling pathway that may underlie differences in 5-HT function and responsivity to drugs that affect 5-HT functioning. In the present study, we examined the relationship between polymorphisms in the promoter region of the gene coding for the neuronal 5-HT transporter, fenfluramine-induced prolactin release, and aggressive impulsivity (as measured by Barratt Impulsivity Scale, Buss-Durkee Hostility Inventory, and Brown-Goodwin Aggression Scale scores), in a group of abstinent alcoholic patients and healthy volunteers. We report here that possession of the short variant of the 5-HT transporter promoter polymorphism was associated with a blunting of overall central 5-HT function, as measured by fenfluramine-induced prolactin release. We found no relationship between aggressive, hostile, or impulsive traits and fenfluramine-induced prolactin release or between these traits and polymorphisms in the 5-HT transporter promoter. Thus, we have shown that a 5-HT transporter promoter genotype, which has previously been associated with anxiety-based behaviors, alters an in vivo measure of central 5-HT function (fenfluramine-induced prolactin release), providing an important mechanism for linkage between a gene, physiological function, and behavior. Published 2001 Wiley-Liss, Inc.

Immunohistochemical and ultrastructural evidence that dendritic cells infiltrate stenotic aortocoronary saphenous vein bypass grafts

We earlier speculated that antigen-presenting dendritic cells may be involved in the immune reactions leading to saphenous vein bypass graft failure. The purpose of this study was to confirm whether dendritic cells are present in stenotic human saphenous vein bypass grafts. Segments of stenotic saphenous vein grafts were explanted from 14 patients at re-do bypass operation and ten normal saphenous veins were harvested during femoro-popliteal grafting. Sections of specimens were analysed using cell type specific antibodies to identify dendritic cells (CD1a, S-100), T-lymphocytes (CD3), macrophages (CD68), smooth muscle cells (alpha-SMA) and endothelial cells (FVIII). Dual immunostaining, confocal immunofluorescent laser scanning microscopy and electron microscopy were used. Stenotic grafts showed structural alterations of intimal hyperplasia and varying degrees of atherosclerotic degeneration. No cells expressing CD1a and S-100 were observed in the intima and media of normal saphenous veins. Cells expressing these antigens were present around areas of medial neovascularization and within intimal atherosclerotic lesions in saphenous vein bypass grafts. Electron microscopy demonstrated the presence of cells containing a well-developed tubulovesicular system which is unique to cells from the dendritic cell family. Double immunohistochemistry and confocal immunofluorescent microscopy revealed the co-localization of T-lymphocytes with dendritic cells. Dendritic cells are present in stenotic saphenous vein bypass grafts. Dendritic cells may be responsible for antigen presentation and modulation of immune reactions in accelerated graft atherosclerosis through their interaction with T-lymphocytes.

Racial and ethnic colorectal cancer patterns affect the cost-effectiveness of colorectal cancer screening in the United States

BACKGROUND & AIMS

Colorectal cancer screening beginning at age 50 is recommended for all Americans considered at "average" risk for the development of colorectal cancer.

METHODS

We used 1988-1995 California Cancer Registry data to compare the cost-effectiveness of two 35-year colorectal cancer screening interventions among Asians, blacks, Latinos, and Whites.

RESULTS

Average annual age-specific colorectal cancer incidence rates were highest in blacks and lowest in Latinos. Screening beginning at age 50 was most cost-effective in blacks and least cost-effective in Latinos (measured as dollars spent per year of life saved), using annual fecal occult blood testing (FOBT) combined with flexible sigmoidoscopy every 5 years and using colonoscopy every 10 years. A 35-year screening program beginning in blacks at age 42, whites at age 44, or Asians at age 46 was more cost-effective than screening Latinos beginning at age 50.

CONCLUSIONS

Colorectal cancer screening programs beginning at age 50, using either FOBT and flexible sigmoidoscopy or colonoscopy in each racial or ethnic group, are within the $40,000-$60,000 per year of life saved upper cost limit considered acceptable for preventive strategies. Screening is most cost-effective in blacks because of high age-specific colorectal cancer incidence rates.

From Bittner to Barr: a viral, diet and hormone breast cancer aetiology hypothesis

It is hypothesized that the human homologue of the mouse mammary tumour virus (HHMMTV) and other viruses, such as human papillomavirus (HPV) and Epstein-Barr virus (EBV), act as cofactors with diet, oestrogens and other hormones in the initiation and promotion of some types of breast cancer in genetically susceptible women. It is further hypothesized that diet influences the risk of breast cancer, through its influence on oestrogen metabolism and that of other hormones, in combination with genetic and infectious agents.

The management of cutaneous leishmaniasis from Belize

We report 20 patients who contracted cutaneous leishmaniasis in Central and South America, 18 of them in Belize. The diagnosis was confirmed by the polymerase chain reaction (PCR) in 79% of those tested; the corresponding figure for histology was 62%, touch smear 46%, and culture 11%. Results of PCR can be falsely positive, so treatment should not be based on PCR alone. Of the 20 cases 18 were healed 6 weeks after intravenous sodium stibogluconate 20 mg/kg per day for 20 days. We present a management protocol.

Mechanism of extracellular calcium regulation of intestinal epithelial tight junction permeability: role of cytoskeletal involvement

Recent studies suggest that an abnormal increase in intestinal tight junction (TJ) permeability may be an important etiologic factor in number of diseases including Crohn's disease, NSAID-associated enteritis, and various infectious diarrheal syndromes. The intracellular processes involved in regulation of intestinal epithelial TJ permeability, however, remain poorly understood. In this study, we used cultured Caco-2 intestinal epithelial cells to examine the intracellular processes involved in extracellular Ca(++) modulation of intestinal epithelial monolayer TJ barrier. Incubation of the filter-grown Caco-2 intestinal monolayers in Ca(++)-free solution (CFS), consisting of modified Krebs-buffer solution containing 0 mM Ca(++) and 1 mM EGTA, resulted in a rapid drop in Caco-2 epithelial resistance and increase in epithelial permeability to paracellular markers mannitol and inulin, indicating an increase in TJ permeability. The increase in Caco-2 TJ permeability was rapidly reversed by the re-introduction of Ca(++) (1.8 mM) into the incubation medium. The CFS-induced increase in Caco-2 TJ permeability was associated with separation of the cytoplasmic and transmembrane TJ proteins, ZO-1 and occludin, and formation of large intercellular openings between the adjoining cells. The CFS-induced modulation of TJ barrier was associated with activation of myosin light chain kinase (MLCK) activity and centripetal retraction of peri-junctional actin and myosin filaments. The inhibition of CFS-induced activation of Caco-2 MLCK with MLCK inhibitor (ML-7) prevented the CFS-induced retraction of actin and myosin filaments and the subsequent alteration of TJ barrier function and structure. Our results suggested that the CFS-induced alteration of TJ proteins and functional increase in TJ permeability was mediated by Caco-2 MLCK activation and the resultant contraction of the peri-junctionally located actin-myosin filaments. Consistent with the role of MLCK in this process, selected inhibitors of Mg(++)-myosin ATPase and metabolic energy, but not protein synthesis inhibitors, also prevented the CFS-induced retraction of actin and myosin filaments and the subsequent increase in TJ permeability. In conclusion, our results indicate that extracellular Ca(++) is crucial for the maintenance of intestinal epithelial TJ barrier function. The removal of extracellular Ca(++) from the incubation medium causes activation of Caco-2 MLCK, which in turn leads to an increase in intestinal monolayer TJ permeability.

Mechanism of extracellular calcium regulation of intestinal epithelial tight junction permeability: role of cytoskeletal involvement

Recent studies suggest that an abnormal increase in intestinal tight junction (TJ) permeability may be an important etiologic factor in number of diseases including Crohn's disease, NSAID-associated enteritis, and various infectious diarrheal syndromes. The intracellular processes involved in regulation of intestinal epithelial TJ permeability, however, remain poorly understood. In this study, we used cultured Caco-2 intestinal epithelial cells to examine the intracellular processes involved in extracellular Ca(++) modulation of intestinal epithelial monolayer TJ barrier. Incubation of the filter-grown Caco-2 intestinal monolayers in Ca(++)-free solution (CFS), consisting of modified Krebs-buffer solution containing 0 mM Ca(++) and 1 mM EGTA, resulted in a rapid drop in Caco-2 epithelial resistance and increase in epithelial permeability to paracellular markers mannitol and inulin, indicating an increase in TJ permeability. The increase in Caco-2 TJ permeability was rapidly reversed by the re-introduction of Ca(++) (1.8 mM) into the incubation medium. The CFS-induced increase in Caco-2 TJ permeability was associated with separation of the cytoplasmic and transmembrane TJ proteins, ZO-1 and occludin, and formation of large intercellular openings between the adjoining cells. The CFS-induced modulation of TJ barrier was associated with activation of myosin light chain kinase (MLCK) activity and centripetal retraction of peri-junctional actin and myosin filaments. The inhibition of CFS-induced activation of Caco-2 MLCK with MLCK inhibitor (ML-7) prevented the CFS-induced retraction of actin and myosin filaments and the subsequent alteration of TJ barrier function and structure. Our results suggested that the CFS-induced alteration of TJ proteins and functional increase in TJ permeability was mediated by Caco-2 MLCK activation and the resultant contraction of the peri-junctionally located actin-myosin filaments. Consistent with the role of MLCK in this process, selected inhibitors of Mg(++)-myosin ATPase and metabolic energy, but not protein synthesis inhibitors, also prevented the CFS-induced retraction of actin and myosin filaments and the subsequent increase in TJ permeability. In conclusion, our results indicate that extracellular Ca(++) is crucial for the maintenance of intestinal epithelial TJ barrier function. The removal of extracellular Ca(++) from the incubation medium causes activation of Caco-2 MLCK, which in turn leads to an increase in intestinal monolayer TJ permeability.

Mechanism of extracellular calcium regulation of intestinal epithelial tight junction permeability: role of cytoskeletal involvement

Recent studies suggest that an abnormal increase in intestinal tight junction (TJ) permeability may be an important etiologic factor in number of diseases including Crohn's disease, NSAID-associated enteritis, and various infectious diarrheal syndromes. The intracellular processes involved in regulation of intestinal epithelial TJ permeability, however, remain poorly understood. In this study, we used cultured Caco-2 intestinal epithelial cells to examine the intracellular processes involved in extracellular Ca(++) modulation of intestinal epithelial monolayer TJ barrier. Incubation of the filter-grown Caco-2 intestinal monolayers in Ca(++)-free solution (CFS), consisting of modified Krebs-buffer solution containing 0 mM Ca(++) and 1 mM EGTA, resulted in a rapid drop in Caco-2 epithelial resistance and increase in epithelial permeability to paracellular markers mannitol and inulin, indicating an increase in TJ permeability. The increase in Caco-2 TJ permeability was rapidly reversed by the re-introduction of Ca(++) (1.8 mM) into the incubation medium. The CFS-induced increase in Caco-2 TJ permeability was associated with separation of the cytoplasmic and transmembrane TJ proteins, ZO-1 and occludin, and formation of large intercellular openings between the adjoining cells. The CFS-induced modulation of TJ barrier was associated with activation of myosin light chain kinase (MLCK) activity and centripetal retraction of peri-junctional actin and myosin filaments. The inhibition of CFS-induced activation of Caco-2 MLCK with MLCK inhibitor (ML-7) prevented the CFS-induced retraction of actin and myosin filaments and the subsequent alteration of TJ barrier function and structure. Our results suggested that the CFS-induced alteration of TJ proteins and functional increase in TJ permeability was mediated by Caco-2 MLCK activation and the resultant contraction of the peri-junctionally located actin-myosin filaments. Consistent with the role of MLCK in this process, selected inhibitors of Mg(++)-myosin ATPase and metabolic energy, but not protein synthesis inhibitors, also prevented the CFS-induced retraction of actin and myosin filaments and the subsequent increase in TJ permeability. In conclusion, our results indicate that extracellular Ca(++) is crucial for the maintenance of intestinal epithelial TJ barrier function. The removal of extracellular Ca(++) from the incubation medium causes activation of Caco-2 MLCK, which in turn leads to an increase in intestinal monolayer TJ permeability.

Mechanism of extracellular calcium regulation of intestinal epithelial tight junction permeability: role of cytoskeletal involvement

Recent studies suggest that an abnormal increase in intestinal tight junction (TJ) permeability may be an important etiologic factor in number of diseases including Crohn's disease, NSAID-associated enteritis, and various infectious diarrheal syndromes. The intracellular processes involved in regulation of intestinal epithelial TJ permeability, however, remain poorly understood. In this study, we used cultured Caco-2 intestinal epithelial cells to examine the intracellular processes involved in extracellular Ca(++) modulation of intestinal epithelial monolayer TJ barrier. Incubation of the filter-grown Caco-2 intestinal monolayers in Ca(++)-free solution (CFS), consisting of modified Krebs-buffer solution containing 0 mM Ca(++) and 1 mM EGTA, resulted in a rapid drop in Caco-2 epithelial resistance and increase in epithelial permeability to paracellular markers mannitol and inulin, indicating an increase in TJ permeability. The increase in Caco-2 TJ permeability was rapidly reversed by the re-introduction of Ca(++) (1.8 mM) into the incubation medium. The CFS-induced increase in Caco-2 TJ permeability was associated with separation of the cytoplasmic and transmembrane TJ proteins, ZO-1 and occludin, and formation of large intercellular openings between the adjoining cells. The CFS-induced modulation of TJ barrier was associated with activation of myosin light chain kinase (MLCK) activity and centripetal retraction of peri-junctional actin and myosin filaments. The inhibition of CFS-induced activation of Caco-2 MLCK with MLCK inhibitor (ML-7) prevented the CFS-induced retraction of actin and myosin filaments and the subsequent alteration of TJ barrier function and structure. Our results suggested that the CFS-induced alteration of TJ proteins and functional increase in TJ permeability was mediated by Caco-2 MLCK activation and the resultant contraction of the peri-junctionally located actin-myosin filaments. Consistent with the role of MLCK in this process, selected inhibitors of Mg(++)-myosin ATPase and metabolic energy, but not protein synthesis inhibitors, also prevented the CFS-induced retraction of actin and myosin filaments and the subsequent increase in TJ permeability. In conclusion, our results indicate that extracellular Ca(++) is crucial for the maintenance of intestinal epithelial TJ barrier function. The removal of extracellular Ca(++) from the incubation medium causes activation of Caco-2 MLCK, which in turn leads to an increase in intestinal monolayer TJ permeability.

Eosinophilic gastroenteritis mimicking acute appendicitis

Eosinophilic gastroenteritis is a rare entity that can be treated successfully with glucocorticoid therapy if the appropriate diagnosis is made. However, it may present with symptomatology mimicking acute surgical conditions. We present the case of a 26-year-old man who presented with diffuse epigastric pain, nausea, vomiting, and diarrhea. Extensive workup including upper endoscopy and imaging study revealed gastritis with ulcer and ascites. The patient developed right lower quadrant pain with localized peritonitis and leukocytosis. He underwent appendectomy and small bowel biopsy. Pathology revealed eosinophilic cellular infiltrate of both the appendiceal and small intestinal wall. The unique features of this condition are reviewed and surgical approaches are discussed.

Use of a supermarket shelf-labeling program to educate a predominately minority community about foods that promote heart health

OBJECTIVE

The purpose of this study was to evaluate the awareness and use of a supermarket-shelf labeling program designed to encourage shoppers to make food choices that promote heart health.

DESIGN

A shelf-labeling program was implemented in 18 supermarkets serving minority communities in Detroit, Mich. Customers were given an exit survey to determine awareness and use of the program.

SUBJECTS/SETTING

Three hundred sixty-one subjects were sampled. Sixty-six percent of the sample was female, 67% African-American, and the sample population had a mean age of 51.6 years +/- 18.5 SD.

RESULTS

Overall awareness of the program was 28.8%. Awareness among minorities was significantly higher when compared with whites (35.3% vs 20.8%; P = .02). Gender, age, and education level were not predictive of program awareness but people screened for cardiovascular disease risk factors (elevated low-density lipoprotein or total cholesterol levels and/or elevated blood pressure) in the previous year had greater awareness than those not screened (32.6% vs 13.6%, P = .06). Use of the program was 56% among subjects aware of the program. This did not differ significantly by gender, age, or ethnicity.

STATISTICAL ANALYSIS

Awareness and use were evaluated with respect to ethnicity, gender, education, race, age, and previous screening history. For purposes of analysis, African-American, Hispanic, and Asian-American respondents were combined into one group called "all minorities." The other group of respondents was called "whites." Between-group differences in categorical variables were analyzed using a chi 2 statistic.

CONCLUSIONS

Awareness of the shelf-labeling program was modest, but highest among African-Americans. Subjects recently screened for cardiovascular disease risk had greater program awareness. This difference was not statistically significant. Use was relatively high among those aware of the program, suggesting that shelf labels have the potential to increase the selection of foods that promote heart health in predominately low-income, minority populations.

Permanent alopecia following chemotherapy and bone marrow transplantation

Alopecia can be a psychologically daunting prospect for people requiring cancer chemotherapy. Fortunately, most patients experience only temporary hair loss. We report the case of a 23-year-old woman with chronic myeloid leukaemia who developed permanent, near-total alopecia of her scalp, eyebrows, eyelashes, axillary and public hair following busulphan and cyclophosphamide chemotherapy which was used as conditioning prior to allogeneic bone marrow transplantation. The histology from a scalp biopsy revealed hair follicle destruction. Topical minoxidil failed to induce significant re-growth.

An electronic menstrual cycle calendar: comparison of data quality with a paper version

OBJECTIVES

This pilot study compared a prototype electronic menstrual calendar on a handheld computer with a paper calendar for data quality and participants' perceptions.

DESIGN

Twenty-three women completed identical information about menstrual bleeding and symptoms using paper and electronic calendars for 1 month each.

RESULTS

Use of the paper calendar resulted in more missing data than the electronic calendar for bleeding characteristics (13% vs. 4%) and symptoms (35% vs. 4%). The electronic calendar's ability to log data entries revealed retrospective entry for 61% of the data. Total data entry and cleaning time was reduced by 81% with the electronic calendar. Overall, participants preferred the electronic (70%) to the paper (22%) calendar.

CONCLUSIONS

Data quality with conventional paper calendars may be poorer than recognized. The data-logging feature, unique to the electronic calendar, is critical for assessing data quality. Electronic menstrual calendars can be useful data collection tools for research in women's health.

Formation and characterization of a single Trp-Trp cross-link in indolicidin that confers protease stability without altering antimicrobial activity

Indolicidin is a 13-residue cationic, antimicrobial peptide-amide isolated from the cytoplasmic granules of bovine neutrophils. The unique composition of indolicidin distinguishes it from alpha-helical and beta-structured cationic peptides, because five of indolicidin's 13 residues are tryptophans: H-Ile-Leu-Pro-Trp-Lys-Trp-Pro-Trp-Trp-Pro-Trp-Arg-Arg-NH(2). Solid phase synthesis of indolicidin gave rise to a minor byproduct that possessed unusual fluorescence and UV absorbance properties compared with authentic indolicidin. The byproduct was purified by combined ion exchange and reversed phase high pressure liquid chromatography steps and was shown be identical to authentic indolicidin in its microbicidal activity against Staphylococcus aureus, Escherichia coli, Candida albicans, and Cryptococcus neoformans. Mass analysis of the byproduct revealed a 2-atomic mass unit reduction compared with indolicidin, suggesting the deprotonation of two indole side chains to form an intrachain delta(1),delta(1)'-ditryptophan derivative. We confirmed the nature of the cross-linked byproduct, termed X-indolicidin, by absorbance and fluorescence spectroscopy, peptide mapping, and sequence analysis. Edman degradation revealed that Trp-6 and Trp-9 were covalently cross-linked. Compared with indolicidin, X-indolicidin was partially resistant to digestion with trypsin and chymotrypsin, suggesting that the ditryptophan stabilizes a subset of molecular conformations that are protease resistant but that are absent in the native structure.

Hematoxylin and safranin O staining of frozen sections

Currently the hematoxylin and eosin staining procedure is the most popular among Mohs surgeons for histology. However, safranin O, a cheaper and relatively safer stain which is predominantly used for plant histology, should be considered as it offers similar or improved accuracy in the diagnosis of frozen sections of basal and squamous cell carcinomas.

Sarcoidosis presenting as tattoo granuloma inadvertently treated with laser therapy

A patient presenting with nodules in his tattoos was referred for laser treatment, following which there was a diagnosis of cutaneous and pulmonary sarcoidosis. Nodular change involving several different tattoo colours is characteristic of sarcoidosis.

Prevalence of Helicobacter pylori infection in 160 patients with Barrett's oesophagus or Barrett's adenocarcinoma

BACKGROUND

The role of Helicobacter pylori infection in the development of Barrett's oesophagus and its complications is uncertain. The aim of the present study was to determine the importance of H. pylori infection in this disease by comparing the frequency of oesophageal and gastric H. pylori infection in a group of patients with Barrett's oesophagus or adenocarcinoma, with the frequency of infection in a control group without Barrett's disease.

METHODS

The study group included 160 patients (123 male, 37 female; mean age: 61.2 years) who were classified (according to the highest grade pathological lesion in the oesophagus) as having Barrett's intestinal metaplasia (IM; 88 patients), Barrett's oesophagus with low-grade dysplasia (LGD; 28 patients), high-grade dysplasia (HGD; five patients), Barrett's indefinite for dysplasia (n = 4), and Barrett's adenocarcinoma (33 patients). A total of 91 of these patients had gastric antral specimens available for study. The control group consisted of 214 consecutive, prospectively enrolled symptomatic patients (122 male, 92 female; mean age: 57.2 years) who underwent upper gastrointestinal endoscopy and in whom Barrett's oesophagus or Barrett's adenocarcinoma was not found. A modified Warthin-Starry method was used to detect H. pylori infection.

RESULTS

Oesophageal H. pylori infection was found in eight of 160 (5%) patients with Barrett's oesophagus or Barrett's adenocarcinoma. Holicobacter pylori organisms in the oesophagus were found only on non-intestinalized cardiac or oxyntocardiac mucosa. All patients with oesophageal H. pylori infection and an antral biopsy available for study had antral H. pylori infection. Gastric antral H. pylori infection was significantly less prevalent in patients in the Barrett's study group (15/91, 16.5%) than in the non-Barrett's control group (67/214, 31.3%; Fisher's exact test, P = 0.01). Patients from the control group with an endoscopic diagnosis of duodenal ulcer, gastric ulcer, gastritis, or duodenitis had a significantly higher prevalence of infection compared with the Barrett's group, but there was no difference in the infection prevalence in patients in the Barrett's group and patients with reflux oesophagitis, hiatal hernia, no endoscopic abnormality, or any other diagnosis.

CONCLUSIONS

Oesophageal H. pylori infection is uncommon in patients with Barrett's IM, dysplasia, or adenocarcinoma, and may be restricted to non-intestinalized columnar epithelium. Gastric H. pylori infection may have a protective effect for the development of Barrett's oesophagus.

Substance P antagonists: the next breakthrough in treating depression?

Several lines of evidence implicate the neuropeptide substance P in depression, either in the pathogenesis or as a novel target for amelioration of symptoms. NK1 (substance P) receptor antagonists have been reported to have antidepressant-like actions in animal models. The first clinical trial of an NK1 antagonist showed promising results. A second trial, using a more potent compound, is underway. If the clinical trials show that NK1 (substance P) antagonism represents a well-tolerated, distinct mechanism for antidepressant activity, novel antidepressant agents will emerge as mono- or adjunct-therapy.

[Paul-Louis Simond and the Marchoux mission in Brazil]

In 1900 the role of a particular mosquito called Stegomyia fasciata in the transmission of yellow fever was proved by a board of American medical officers. This discovery was the beginning of several scientific missions in South America, mostly in Brazil. As yellow fever was increasing in its West African colonies, the French government decided to send a scientific mission to Rio de Janeiro, to find new ways of prevention against the disease. Under the authority of the Institut Pasteur, Paul-Louis Simond, who had just discovered the role of the flea in the transmission of plague, was designated to carry through this mission together with Emile Marchoux and Alexandre Salimbeni, eminent Pasteurians like him. From November 1901 to May 1905, the three men studied the epidemiological and clinical aspects of the disease in Rio. They worked on the intermediate host's entomology, the Stegomyia female mosquito, improving the knowledge of yellow fever and its means of transmission. They also realized experiments on 25 healthy volunteers, submitting them to the bite of infected mosquitoes. They were among the first to proceed to yellow féver vaccinations by means of virulent serum heated to 55 degrees C or filtered. Their work led to the establishment of new sanitary rules to prevent the spread of the disease. This contributed to the success of the "yellow fever campaign" initiated by Oswaldo Cruz in the town of Rio. One of the most original contribution of their studies was to show that the yellow fever agent (which was still unknown) could be transmitted from an infected female Stegomyia to its eggs and larvaes. After this mission, the French authorities were able to fight yellow fever efficiently in their African colonies as well as in the West Indies and French Guyana.

Peptide localization and gene structure of cryptdin 4, a differentially expressed mouse paneth cell alpha-defensin

Paneth cells in crypts of the small intestine express antimicrobial peptides, including alpha-defensins, termed cryptdins in mice. Of the known Paneth cell alpha-defensins, the cryptdin 4 gene is unique, because it is inactive in the duodenum and expressed at maximal levels in the distal small bowel (D. Darmoul and A. J. Ouellette, Am. J. Physiol. 271:G68-G74, 1996). With a cryptdin 4-specific antibody, immunohistochemical staining of ileal Paneth cells was strong and specific for cytoplasmic granules, demonstrating that this microbicidal peptide is a secretory product of Paneth cells in the distal small intestine. Consistent with the pattern of cryptdin 4 mRNA distribution along the length of the gut, the cryptdin 4 peptide was not detected in duodenum. Structurally, the cryptdin 4 gene resembles other Paneth cell alpha-defensin genes. Its two exons, transcriptional start site, intron, splice sites, and 3' flanking sequences are characteristic of the highly conserved mouse alpha-defensin genes. However, in the region upstream of the transcriptional initiation site, the cryptdin 4 gene contains a repeated 130-bp element that is unique to this alpha-defensin gene. Every independent cryptdin 4 genomic clone examined carries the repeated element, which contains putative recognition sequences for TF-IID-EIIA, cMyc-RS-1, and IgHC.2/CuE1.1; the repeat proximal to the start of transcription replaces DNA at the corresponding position in other mouse alpha-defensin genes. We speculate that this unique duplicated element may have a cis-acting regulatory role in the positional specificity of cryptdin 4 gene expression.

Low oestrogen receptor alpha expression in normal breast tissue underlies low breast cancer incidence in Japan

Among white Australians without breast cancer, the median of the percentage of oestrogen receptor alpha positive cells was 12% for women younger than 50 years and 17% for those 50 years or older; among Japanese women who had no breast cancer and are generally at low risk for this disease, the corresponding values were both significantly lower and around 9%.

A cyclic antimicrobial peptide produced in primate leukocytes by the ligation of two truncated alpha-defensins

Analysis of rhesus macaque leukocytes disclosed the presence of an 18-residue macrocyclic, tridisulfide antibiotic peptide in granules of neutrophils and monocytes. The peptide, termed rhesus theta defensin-1 (RTD-1), is microbicidal for bacteria and fungi at low micromolar concentrations. Antibacterial activity of the cyclic peptide was threefold greater than that of an open-chain analog, and the cyclic conformation was required for antimicrobial activity in the presence of 150 millimolar sodium chloride. Biosynthesis of RTD-1 involves the head-to-tail ligation of two alpha-defensin-related nonapeptides, requiring the formation of two new peptide bonds. Thus, host defense cells possess mechanisms for synthesis and granular packaging of macrocyclic antibiotic peptides that are components of the phagocyte antimicrobial armamentarium.

Involvement of dendritic cells in long-term aortocoronary saphenous vein bypass graft failure

Antigen-presenting dendritic cells are present in atherosclerotic lesions in human arterial intima, but have not been investigated in atherosclerotic and hyperplastic stenotic lesions that affect vein grafts used as arterial conduits. This study was undertaken to examine whether dendritic cells are present in aortocoronary artery saphenous vein bypass grafts affected by high-grade atheromatous stenosis. Stenotic saphenous vein coronary artery bypass grafts (angiographic luminal stenosis > 75%) were harvested from 10 patients (nine male, one female), aged 4271 years (mean 56.5) at re-do operation. The mean time interval from bypass surgery to the excision of stenotic grafts was 11.5 years (range 2-21). The specimens were fixed in 10% buffered formalin, embedded in paraffin blocks and the sections stained with antibodies to S-100 (to identify dendritic cells), CD3 (T cells), CD68 (macrophages), von Willebrand factor (endothelial cells) and alpha-smooth muscle actin (smooth muscle cells) using avidin-biotin complex immunoperoxidase technique. Normal veins were obtained during saphenous vein femoro-popliteal grafting. The stenotic venous grafts showed histological features typical of extensive arterialization, intimal hyperplasia, atherosclerotic plaque-like lesions, calcification and thrombosis. In areas of intimal hyperplasia, S-10O-positive cells were distributed irregularly among smooth muscle cells. S-100-positive dendritic cells were seen most frequently within atherosclerotic plaque-like lesions where they co-localized with CD3+ cells and CD68+ cells. S-100-positive dendritic cells were also seen accumulating within calcific foci. No S-100-positve cells were found in normal, ungrafted saphenous veins. We conclude that dendritic cells are present in aortocoronary saphenous vein bypass grafts affected by high grade stenosis. Dendritic cells are probably involved in immune mechanisms of atherogenesis through their interactions with T cells and macrophages. The accumulation of dendritic cells within calcific foci suggests their contribution to the calcification of stenotic venous grafts.

Different mutator phenotypes in Mlh1- versus Pms2-deficient mice

Deficiencies in DNA mismatch repair (MMR) result in increased mutation rates and cancer risk in both humans and mice. Mouse strains homozygous for knockouts of either the Pms2 or Mlh1 MMR gene develop cancer but exhibit very different tumor spectra; only Mlh1(-/-) animals develop intestinal tumors. We carried out a detailed study of the microsatellite mutation spectra in each knockout strain. Five mononucleotide repeat tracts at four different chromosomal locations were studied by using single-molecule PCR or an in vivo forward mutation assay. Three dinucleotide repeat loci also were examined. Surprisingly, the mononucleotide repeat mutation frequency in Mlh1(-/-) mice was 2- to 3-fold higher than in Pms2(-/-) animals. The higher mutation frequency in Mlh1(-/-) mice may be a consequence of some residual DNA repair capacity in the Pms2(-/-) animals. Relevant to this idea, we observed that Pms2(-/-) mice exhibit almost normal levels of Mlh1p, whereas Mlh1(-/-) animals lack both Mlh1p and Pms2p. Comparison between Mlh1(-/-) animals and Mlh1(-/-) and Pms2(-/-) double knockout mice revealed little difference in mutator phenotype, suggesting that Mlh1 nullizygosity is sufficient to inactivate MMR completely. The findings may provide a basis for understanding the greater predisposition to intestinal cancer of Mlh1(-/-) mice. Small differences (2- to 3-fold) in mononucleotide repeat mutation rates may have dramatic effects on tumor development, requiring multiple genetic alterations in coding regions. Alternatively, this strain difference in tumor spectra also may be related to the consequences of the absence of Pms2p compared with the absence of both Pms2p and Mlh1p on as yet little understood cellular processes.

Distribution of signaling molecules involved in vasopressin-induced Ca2+ mobilization in rat hepatocyte multiplets

In freshly isolated rat hepatocyte multiplets, Ca2+ signals in response to vasopressin are highly organized. In this study we used specific probes to visualize, by fluorescence and confocal microscopy, the main signaling molecules involved in vasopressin-mediated Ca2+ responses. V1a receptors were detected with a novel fluorescent antagonist, Rhm8-PVA. The Galphaq/Galpha11, PLCbeta3, PIP2, and InsP3 receptors were detected with specific antibodies. V1a vasopressin receptors and PIP2 were associated with the basolateral membrane and were not detected in the bile canalicular domain. Galphaq/Galpha11, PLCbeta3, and InsP3 receptors were associated with the basolateral membrane and also with other intracellular structures. We used double labeling, Western blotting, and drugs (cytochalasin D, colchicine) known to disorganize the cytoskeleton to demonstrate the partial co-localization of Galphaq/Galpha11 with F-actin.

Smoking and lipid cardiovascular risk factors in Vietnamese refugees in Australia

BACKGROUND

The effects of smoking and sex on lipid risk factors for cardiovascular disease were examined among Vietnamese people newly arrived in Australia.

METHODS

Immigrants recruited through Refugee Screening had anthropometric data recorded and blood collected to measure total cholesterol (TC), high-density lipoprotein cholesterol (HDL), and triglyceride (TG) by Reflotron; apolipoprotein A-1 (apo A-1) and apolipoprotein B-100 (apo B) by immunoturbidimetric analyses (Turbitimer); and lipoprotein (a) (LP (a)) by ELISA. A questionnaire determined behavioral variables known to influence cardiovascular risk and Statview, Minitab, and SPSS were employed for data analysis.

RESULTS

Lipoprotein profiles of men (n = 242) and women (n = 159) were compared. Crude TC and apo B were similar; HDL, apo A-1, and LP (a) were higher in women, TG was higher in men. After adjustment (age, BMI, WHR, years of smoking, and drinks per week), only apo A-1 and LP (a), were higher in women. "At risk" levels of TC or apo B did not differ by gender; risk of low apo A-1 was higher among men. Smokers had a significant risk (crude and adjusted) of low HDL, low apo A-1, and high LP (a). The sex difference in HDL was removed by a single adjustment for smoking; male smokers had higher LP (a) than male nonsmokers.

CONCLUSION

Male and female Vietnamese immigrants had similar adjusted lipid profiles. Smoking had a marked detrimental effect on lipids.

Visualization of cell surface vasopressin V1a receptors in rat hepatocytes with a fluorescent linear antagonist

To visualize cell surface V1a vasopressin receptors in rat hepatocytes in the absence of receptor-mediated endocytosis, we used a high-affinity fluorescent linear antagonist, Rhm8-PVA. Epifluorescence microscopy (3CCD camera) and fluorescence spectroscopy were used. Rhm8-PVA alone did not stimulate Ca2+ signals and competitively blocked Ca2+ signals (Kinact of 3.0 nM) evoked by arginine vasopressin (vasopressin). When rat hepatocytes were incubated with 10 nM of Rhm8-PVA for 30 min at 4C, the fluorescent antagonist bound to the surface of cells, presumably the plasma membrane. The V1a receptor specificity of Rhm8-PVA binding was confirmed by its displacement by the nonfluorescent antagonist V4253 and by the natural hormone vasopressin at 4C. Prior vasopressin-mediated endocytosis of V1a receptors at 37C abolished binding of the labeled antagonist, whereas in non-preincubated cells, Rhm8-PVA labeled the cell surface of rat hepatocytes. When cells labeled with Rhm8-PVA at 4C were warmed to 37C to initiate receptor-mediated internalization of the fluorescent complex, Rhm8-PVA remained at the cell surface. Incubation temperature at 4C or 37C had little effect on binding of Rhm8-PVA. We conclude that Rhm8-PVA is unable to evoke receptor-mediated endocytosis and can readily be used to visualize cell surface receptors in living cells.

Understanding and managing common baldness

BACKGROUND

Society places importance on physical attributes especially the appearance of our hair. Common baldness or androgenetic alopecia is a normal physiological process of hair loss in genetically predisposed individuals. Premature or accelerated hair loss can engender considerable negative thoughts and anxiety associated with feelings of diminished attractiveness.

OBJECTIVE

To enable general practitioners to recognise the various treatment options available, therefore offering patients reasonable hope and informed choices.

DISCUSSION

Common baldness can be prevented by currently available mediums and regrowth may be achieved in a significant percentage of cases. Correct use of these agents requires an understanding of the pathogenesis of androgenetic alopecia, its natural history and the time course of response to treatment.