Non-fatal opioid overdose, naloxone access, and naloxone training among people who recently used opioids or received opioid agonist treatment in Australia: The ETHOS Engage study

BACKGROUND

Overdose is a major cause of morbidity and mortality among people who use opioids. Naloxone can reverse opioid overdoses and can be distributed and administered with minimal training. People with experience of overdose are a key population to target for overdose prevention strategies. This study aims to understand if factors associated with recent non-fatal opioid overdose are the same as factors associated with naloxone access and naloxone training in people who recently used opioids or received opioid agonist treatment (OAT).

METHODS

ETHOS Engage is an observational study of people who inject drugs in Australia. Logistic regression models were used to estimate odds ratios for non-fatal opioid overdose, naloxone access and naloxone training.

RESULTS

Between May 2018-September 2019, 1280 participants who recently used opioids or received OAT were enrolled (62% aged >40 years; 35% female, 80% receiving OAT, 62% injected drugs in the preceding month). Recent opioid overdose (preceding 12 months) was reported by 7% of participants, lifetime naloxone access by 17%, and lifetime naloxone training by 14%. Compared to people receiving OAT with no additional opioid use, recent opioid, benzodiazepine (preceding six months), and hazardous alcohol use was associated with recent opioid overdose (aOR 3.91; 95%CI: 1.68-9.10) and lifetime naloxone access (aOR 2.12; 95%CI 1.29-3.48). Among 91 people who reported recent overdose, 65% had never received take-home naloxone or naloxone training.

CONCLUSIONS

Among people recently using opioids or receiving OAT, benzodiazepine and hazardous alcohol use is associated with non-fatal opioid overdose. Not all factors associated with non-fatal overdose correspond to factors associated with naloxone access. Naloxone access and training is low across all groups. Additional interventions are needed to scale up naloxone provision.

Trends in hepatocellular carcinoma incidence and survival among people with hepatitis C: An international study

This study evaluates trends in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) incidence and survival in three settings, prior to introduction of direct-acting antiviral (DAA) therapies. HCV notifications from British Columbia (BC), Canada; New South Wales (NSW), Australia; and Scotland (1995-2011/2012/2013, respectively) were linked to HCC diagnosis data via hospital admissions (2001-2012/2013/2014, respectively) and mortality (1995-2013/2014/2015, respectively). Age-standardized HCC incidence rates were evaluated, associated factors were assessed using Cox regression, and median survival time after HCC diagnosis was calculated. Among 58 487, 84 529 and 31 924 people with HCV in BC, NSW and Scotland, 734 (1.3%), 1045 (1.2%) and 345 (1.1%) had an HCC diagnosis. Since mid-2000s, HCC diagnosis numbers increased in all jurisdictions. Age-standardized HCC incidence rates remained stable in BC and Scotland and increased in NSW. The strongest predictor of HCC diagnosis was older age [birth <1945, aHR in BC 5.74, 95% CI 4.84, 6.82; NSW 9.26, 95% CI 7.93, 10.82; Scotland 12.55, 95% CI 9.19, 17.15]. Median survival after HCC diagnosis remained stable in BC (0.8 years in 2001-2006 and 2007-2011) and NSW (0.9 years in 2001-2006 and 2007-2013) and improved in Scotland (0.7 years in 2001-2006 to 1.5 years in 2007-2014). Across the settings, HCC burden increased, individual-level risk of HCC remained stable or increased, and HCC survival remained extremely low. These findings highlight the minimal impact of HCC prevention and management strategies during the interferon-based HCV treatment era and form the basis for evaluating the impact of DAA therapy in the coming years.

Prognosis of 1169 hepatitis C chronically infected patients with decompensated cirrhosis in the predirect-acting antiviral era

At a population level, little is known regarding the risk of liver- and nonliver-related mortality and hospitalization and the development of hepatocellular carcinoma (HCC) in hepatitis C virus (HCV)-infected patients with decompensated cirrhosis (DC). This large-scale national record-linkage study estimates these outcomes following first hospital admission for DC. Record-linkages between national HCV diagnosis and clinical databases and the national inpatient hospital episode database and mortality register were conducted to follow-up the disease course of all identified HCV-diagnosed and chronically infected persons. The study population consisted of 1169 HCV chronically infected persons who had a first hospital admission for DC within the period 1994-2013. We observed an overall average annual percentage change of 12.6% in new DC patients (from 63 in 1994-1999 to 541 in 2009-2013), with no evidence for any improvement in the relative risks of liver-related or all-cause death over time. Between 1 January 1994 and 31 May 2014, 722 and 95 DC patients had died of a liver- and a nonliver-related cause, respectively, and 106 patients had a subsequent first admission for HCC. The 5-year cumulative incidence of liver-related mortality, nonliver-related mortality and first subsequent HCC admission was 61.3%, 8.2% and 8.8%, respectively. The health burden in HCV-infected patients associated with development of decompensated cirrhosis has increased dramatically over the last 20 years. Our findings establish the baseline mortality and HCC progression rates in DC patients against which the impact of new antiviral therapies can be measured.

Look Different: Effect of Radiation Hormesis on the Survival Rate of Immunosuppressed Mice

BACKGROUND

Hormesis is defined as the bio-positive response of something which is bio-negative in high doses. In the present study, the effect of radiation hormesis was evaluated on the survival rate of immunosuppressed BALB/c mice by Cyclosporine A.

MATERIAL AND METHODS

We used 75 consanguine, male, BALB/c mice in this experiment. The first group received Technetium-99m and the second group was placed on a sample radioactive soil of Ramsar region (800Bq) for 20 days. The third group was exposed to X-rays and the fourth group was placed on the radioactive soil and then injected Technetium-99m. The last group was the sham irradiated control group. Finally, 30mg Cyclosporine A as the immunosuppressive agent was orally administered to all mice 48 hours after receiving X-rays and Technetium-99m. The mean survival rate of mice in each group was estimated during time.

RESULTS

A log rank test was run to determine if there were differences in the survival distribution for different groups and related treatments. According to the results, the survival rate of all pre-irradiated groups was more than the sham irradiated control group (p < .05). The highest survival time was related to the mice which were placed on the radioactive soil of Ramsar region for 20 days and then injected Technetium-99m.

CONCLUSION

This study confirmed the presence of hormetic models and the enhancement of survival rate in immunosuppressed BALB/c mice as a consequence of low-dose irradiation. It is also revealed the positive synergetic radioadaptive response on survival rate of immunosuppressed animals.

Effect of treatment willingness on specialist assessment and treatment uptake for hepatitis C virus infection among people who use drugs: the ETHOS study

Among people who inject drugs (PWID) with chronic HCV, the association between HCV treatment willingness and intent, and HCV specialist assessment and treatment were evaluated. The Enhancing Treatment for Hepatitis C in Opioid Substitution Settings (ETHOS) is a prospective observational cohort. Recruitment was through six opioid substitution treatment clinics, two community health centres and one Aboriginal community controlled health organisation in Australia. Analyses were performed using logistic regression. Among 415 participants (mean age 41 years, 71% male), 67% were 'definitely willing' to receive HCV treatment and 70% reported plans to initiate therapy 12 months postenrolment. Those definitely willing to receive HCV treatment were more likely to undergo specialist assessment (64% vs 32%, P < 0.001) and initiate therapy (36% vs 9%, P < 0.001), compared to those with lower treatment willingness. Those with early HCV treatment plans were more likely to undergo specialist assessment (65% vs 27%, P < 0.001) and initiate therapy (36% vs 5%, P < 0.001), compared to those without early plans. In adjusted analyses, HCV treatment willingness independently predicted specialist assessment (aOR 3.06, 95% CI 1.90, 4.94) and treatment uptake (aOR 4.33, 95% CI 2.14, 8.76). In adjusted analysis, having early HCV treatment plans independently predicted specialist assessment (aOR 4.38, 95% CI 2.63, 7.29) and treatment uptake (aOR 9.79, 95% CI 3.70, 25.93). HCV treatment willingness was high and predicted specialist assessment and treatment. Strategies for enhanced HCV care should be developed with an initial focus on people willing to receive treatment and to increase treatment willingness among those less willing.

A Comparative Study on the Life-Saving Radioprotective Effects of Vitamins A, E, C and Over-the-Counter Multivitamins

INTRODUCTION

Oral intake of vitamins which present antioxidant characteristics can protect living organisms against oxidative damage caused by exposure to ionizing radiation. It was previously reported that administration of high levels of vitamin C can lead to increased DNA damage through production of hydroxyl radicals from hydrogen peroxide by the Fenton reaction. However, our early experiments did not confirm this hypothesis. The main goal of this study was to determine if high doses of Vit C can show life-saving radioprotective effects.

MATERIALS AND METHODS

Phase I: Seventy two male Balb/c mice weighing 20-25g were randomly divided into six groups of 12 animals each. Group I; Vit E for five days, Groups II and III; Vit C and Vit A. Group 4; all three vitamins. Group V; an over-the-counter multivitamin. Group VI; none of the above. Phase II: 120 male BALB/c mice weighing 20-25g were randomly divided into 12 groups of 10 each. Group I; Vit A for five days. Groups II-IV; Vit C 200 mg/kg, 400 mg/kg, 800 mg/kg, respectively. Group V-VII; Vit E at daily doses of 200 iu/kg, 400 iu/kg, 800 iu/kg, respectively. Group VIII and IX; all three vitamins at low and high doses, respectively. Group X; an over-the-counter multivitamin. Group XI; controls group and Group XII; received pure olive oil. All animals (Phases I and II) were exposed to a lethal dose of gamma rays and the survival rates of the animals were monitored and recorded continuously for 16 days after exposure.

RESULTS

Phase I: 14 days after irradiation the survival rate for control group was 33.33%, while the survival rates for the 1st to 5th groups were 45.45%, 81.81%, 50%, 57.14%, and 9.09% , respectively. Phase II: The survival rates in the control group and the group that only received pure olive oil, were 50% and 60%, respectively. Survival rate in the animals received Vit C at daily doses of 200 mg/kg, 400 mg/kg, 800 mg/kg, were 90%, 90% and 90%, respectively. Log rank (Mantel-Cox) test showed statistically significant differences between the survival rates in control irradiated mice (no vitamins) and mice received Vit C at daily doses of 200 mg/kg (P=0.042), 400 mg/kg (P=0.042) and 800 mg/kg (P=0.042).

CONCLUSION

Altogether, findings of this study showed that even high doses of Vit C can show life-saving radioprotective effects. The significant radioprotective effect of Vit C at doses used in this study, opens new horizons in developing non-toxic, cost effective, easily available radioprotectors in life-threatening situations such as exposure to lethal doses of ionizing radiation.  The radioprotective effect of Vit A and Vit E seem to be less efficient compared to that of Vit C.

Lower life expectancy among people with an HCV notification: a population-based linkage study

Among people with hepatitis C virus (HCV) infection, liver disease-related deaths have risen over the last 20 years. Life expectancy has not been estimated in this population. HCV notifications (mandatory notification of anti-HCV-positive serology since 1991) reported to the New South Wales Health Department from 1992 to 2006 were linked to cause of death data. Abridged life tables were constructed from age-specific mortality rates. Life expectancy from ages 18-70 years for non-drug-related mortality causes was estimated using competing risk methods and compared to the general population of Australia. The cohort comprised 81 644 individuals with an HCV notification, with median follow-up of 7.6 years. Median age at notification was 34 years [interquartile range (IQR) 28-42] and 63% were male. Between 1992 and 2006, 4607 deaths occurred. Median age at liver- and drug-related death among males was 51 (IQR 45-66) and 36 (IQR 31-42) years, respectively, and among females was 63 (IQR 49-74) and 36 (IQR 30-41) years, respectively. In each year of follow-up before 2000, 15-21% of deaths were liver- and 30-39% were drug-related. After 2000, liver-related deaths increased to 20-26% of deaths in each year and drug-related deaths decreased to 13-19%. Excluding drug-related causes of death, life expectancy was lowered by an average of 4.2 (SD ± 1.0) and 5.4 (SD ± 0.7) years for males and females, respectively. Among people with an HCV notification, an increasing proportion of deaths are liver-related. Following removal of drug-related mortality, life expectancy in this population remained considerably lower, compared with the general population.

Radiography finding in the jaws in children taking bisphosphonate

BACKGROUND

Bisphosphonates‎ inhibit osteoclasts, prevent bone resorption and decrease bone turnover. This study examined radiography finding in bisphosphonate-associated osteonecrosis of jaws.

MATERIALS AND METHODS

This is a retrospective series of 12 clinically diagnosed patients between 7 to 21 year old (average 13 years). They required emergency dental conditions requiring management by dentist: non healing ‎extraction sockets and pain of bone exposure. The panoramic radiography and cone beam computed tomography was performed ‎to assess the problem. Thickening of the lamina dura was observed in 7 patients (58.3 %). But full-thickness sclerosis was seen in 6 patients (50 %). Sclerotic changes in the mandibular canal were noted in 3 patients (25 %). 5 patients (41.6 %) had poorly healing or non-healing of socket in extracted tooth and periapical lucencies. 4 people (33.3 %) had widening of periodontal ligament (PDL) space and osteolysis. Sequestra were seen in 3 persons (25 %). Finally in 2 children (16.6 %) were found oroantral fistula. Only one child (8.3 %) had thickening of soft tissue mid periosteal reaction.

RESULTS

Most patients had some degree of osteosclerosis, especially in the area of alveolar bone. Thickening of the lamina dura was also seen in children. Other findings include: osteolysis, sequestra, periosteal new bone formation, widening of PDL,soft tissue thickening, non healing extraction sockets, oroantral fistula and periapical lucencies (P-value < 0.05).

CONCLUSION

Common radiographic features in patients taking bisphosphonate, was osteosclerosis. This sclerosis had different views that thickening of the lamina dura and alveolar crest were most common.

A novel device for automatic withdrawal and accurate calibration of 99m-technetium radiopharmaceuticals to minimise radiation exposure to nuclear medicine staff and patient

A Joint Automatic Dispenser Equipment (JADE) has been designed and fabricated for automatic withdrawal and calibration of radiopharmaceutical materials. The thermoluminescent dosemeter procedures have shown a reduction in dose to the technician's hand with this novel dose dispenser system JADE when compared with the manual withdrawal of (99m)Tc. This system helps to increase the precision of calibration and to minimise the radiation dose to the hands and body of the workers. This paper describes the structure of this device, its function and user-friendliness, and its efficacy. The efficacy of this device was determined by measuring the radiation dose delivered to the hands of the nuclear medicine laboratory technician. The user-friendliness of JADE has been examined. The automatic withdrawal and calibration offered by this system reduces the dose to the technician's hand to a level below the maximum permissible dose stipulated by the international protocols. This research will serve as a backbone for future study about the safe use of ionising radiation in medicine.

Pseudoaneurysm of mitro-aortic intervalvular fibrosa during the course of mitral valve endocarditis with aorto-left ventricle outflow tract fistula

The mitro-aortic intervalvular fibrosa (MAIVF) connects the anterior mitral leaflet to the posterior portion of the aortic annulus. The pseudoaneurysm of MAIVF is one of the uncommon but catastrophic complications of native or prosthetic aortic valve endocarditis or chest trauma. We report a case of infective endocarditis of mitral valve complicated by development of pseudoaneurysm of MAIVF, and fistulous formation causing massive shunt flow from the ascending aorta above the non-coronary cusp to the left ventricle outflow tract.

Study of the rheological properties of polypropylene/talc/nanoclay ternary hybrid nano composites

Modification of polypropylene (PP) properties by the addition of particulate fillers has been of interest for several years. In the recent years, the simultaneous use of nanofillers and conventional reinforcing fillers and study of the effect of these hybrid systems on various properties of composite has gained the attention of many researchers. In this paper, nanocomposites based on PP/Talc/Nanoclay were prepared at various filler levels via melt compounding of the ingredients in a twin-screw extruder. Here, a polypropylene grafted maleic anhydride (PP-g-MA)/Nanoclay master batch was prepared at 140 oC. The masterbatch was then used to prepare ternary compounds through a simultaneous feeding system, in a ZSK extruder at 210 °C. The extrudate was granulated and then re-extruded through a slit die, to prepare the test specimens. SEM and XRD analysis were used to characterise the systems. Rheological behaviour of the specimens was studied using a parallel plate rheometer. In the ternary blend on comparing with the neat PP, the complex viscosity (η*) is increased with increasing overall filler content; however, at low frequencies this increase is governed by the content of nano filler while at high frequencies it is mainly determined by talc content. A similar trend was also observed for the variations of storage modulus (G′) and loss modulus (G″) with frequency. The results showed that the simultaneous use of nano and micro size fillers considerably affects the melt elasticity. It is believed that the hybrid system increases the hydrodynamic effect of filler particles in the molecular motion of the polymer.

Effect of magnesium sulfate on extubation time and acute pain in coronary artery bypass surgery

BACKGROUND

Post-operative pain control is one of the greatest concerns for both physicians and patients. In this study, the effect of magnesium sulfate (MgSO(4)) solution infusion on post-operative pain scores and extubation time in patients undergoing elective coronary artery bypass graft (CABG) surgeries was assessed.

METHODS

In a double-blind, randomized, placebo-controlled clinical trial, 218 patients scheduled for elective CABG were selected and randomly assigned to two groups. After matching inclusion and exclusion criteria for the patients, intravenous MgSO(4) was administered intraoperatively for one group and placebo to the second group. Except for this, all the cases were similar regarding anesthesia and surgery.

RESULTS

The MgSO(4) patients were extubated sooner compared with the placebo group. Pain scores reported by the group who received MgSO(4) were less at the 6th, 12th, 18th and 24th hours after the operation; also, they needed less morphine sulfate during this period.

CONCLUSION

The results demonstrated a significantly shortened post-operative time for extubation and reduced acute post-operative pain scores by intravenous MgSO(4) infusion during elective CABG surgery.

A distinct intermediate of RNase A is induced by sodium dodecyl sulfate at its pKa

The chemical denaturation of RNase A was found to be mediated by sodium dodecyl sulfate (SDS) at various pH. The characterization of the unfolding pathway was investigated by spectrophotometry and differential scanning calorimetry (DSC), and was analyzed by multivariate curve resolution (MCR) as a chemometric method. The spectrophotometric titration curve of RNase A upon interaction with SDS indicated a distinct complex intermediate in glycine buffer at pH 3.3. This was accompanied with the catalytic activation of the enzyme and was concurrent with maximum population of the intermediate, determined by MCR. This was confirmed by the DSC profile of RNase A in the presence of SDS, indicated by two transitions in thermal unfolding. The kinetic data on the unfolding process of RNase A upon addition of SDS showed a two-phase pathway under the same conditions. The intermediate appeared at low pH especially at the pK(a) of SDS (pH 3.3). These results provide strong evidence of the influence of low pH (around the pK(a) of SDS) on the existence of an intermediate upon interaction of RNase A with SDS.

Development of two PCR-based techniques for detecting helical and coccoid forms of Helicobacter pylori

The primary mode of transmission of Helicobacter pylori, a human pathogen carried by more than half the population worldwide, is still unresolved. Some epidemiological data suggest water as a possible transmission route. H. pylori in the environment transforms into a nonculturable, coccoid form, which frequently results in the failure to detect this bacterium in environmental samples by conventional culture techniques. To overcome limitations associated with culturing, molecular approaches based on DNA amplification by PCR have been developed and used for the detection of H. pylori in clinical and environmental samples. Our results showed the glmM gene as the most promising target for detection of H. pylori by PCR amplification. Under optimal amplification conditions, glmM-specific primers generated PCR-amplified products that were specific for H. pylori and some other Helicobacter species. Genome sequence analysis revealed the existence of a conserved region linked to a hypervariable region upstream of the 16S rRNA gene of H. pylori. Selective PCR primer sets targeting this sequence were evaluated for the specific detection of H. pylori. One primer set, Cluster2 and B1J99, were shown to be highly specific for H. pylori strains and did not produce any PCR products when other Helicobacter species and other bacterial species were analyzed. In tests with 32 strains of H. pylori, 6 strains of other Helicobacter species, 8 strains of Campylobacter jejuni, and 21 strains belonging to different genera, the primers for glmM were selective for the Helicobacter genus and the primers containing the region flanking the 16S rRNA gene were selective for H. pylori species only. The combination of two sensitive PCR-based methods, one targeting the glmM gene and the other targeting a hypervariable flanking region upstream of the 16S rRNA gene, are complementary to each other. Whereas the glmM-specific primers provide a rapid, sensitive presumptive assay for the presence of H. pylori and closely related Helicobacter spp., the primers for sequences flanking the 16S rRNA gene can confirm the presence of H. pylori and locate the potential source of this bacterium.

Effect of renal transplantation on sperm quality and sex hormone levels

OBJECTIVE

To assess the effect of successful renal transplantation on semen variables, sexual function and sex hormone profiles in a clinical trial.

PATIENTS AND METHODS

Thirty patients on haemodialysis underwent renal transplantation; before and after surgery, their sperm density, motility and morphology were analysed, follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin and testosterone levels measured and compared, and sexual function assessed using an abbreviated version of the International Index of Erectile Function (IIEF), with a successful outcome defined as a level of satisfaction of 4 or 5 on a 5-point scale. The paired t-test was used to assess the statistically significance of differences in all analyses.

RESULTS

Sperm motility improved significantly (P < 0.001) but there were no significant changes in morphology or density (P = 0.33 and 0.068, respectively). Testosterone levels increased and FSH, LH and prolactin decreased significantly (P < 0.05) after renal transplantation. The IIEF showed that of the 30 patients, 14 were impotent before surgery and only six remained so afterward (P < 0.05).

CONCLUSION

Although sperm morphology and density did not improve after renal transplantation, there were highly significant changes in sperm motility. Hormonal levels in patients on haemodialysis improved after transplantation and returned to nearly normal; sexual function was also significantly better. Further studies are needed to confirm these results.

Antihyperlipidaemic and antihypercholesterolaemic effects of Anethum graveolens leaves after the removal of furocoumarins

Serum triacylglycerides and total cholesterol levels in rats, with hyperlipidaemia induced by diet, were determined after oral adminstration of a water extract of Anethum graveolens leaves before and after the extraction of the furocoumarin content of the leaves. Administration of the extracts consecutively for 14 days reduced the triacylglycerides and total cholesterol levels by almost 50 and 20%, respectively. Chloroform extraction of furocoumarins from the aqueous extracts did not reduce the antihyperlipidaemic potential of the extracts to a significant degree. Oral administration of the essential oil of A. graveolens seeds, at two different doses, also reduced the triacylglyceride levels by almost 42%. The total cholesterol level was not reduced by the same doses of the essential oil.

Coexistence of antitopoisomerase I and anticentromere antibodies in patients with systemic sclerosis

BACKGROUND

Antibodies targeting DNA topoisomerase I (ATA) or centromere proteins (ACA) are associated with clinical subsets of patients with systemic sclerosis (SSc). The occurrence of those autoantibodies is considered to be mutually exclusive.

OBJECTIVE

To describe the clinical and immunogenetic data of three patients who are co-expressing both antibodies, and then review previous publications.

METHODS

Both antibodies were detected by different methods, including indirect immunofluorescence technique, enzyme linked immunosorbent assay, immunodiffusion, and immunoblot. Patients were HLA typed by serological and molecular genetic methods. Data were extracted from published reports for comparison. The search for published studies was through Medline and other database research programmes.

RESULTS

During routine laboratory diagnostics over several years three patients with scleroderma and coincidence of ATA and ACA were identified: patient 1 with diffuse SSc, Raynaud's phenomenon, puffy fingers and fingertip necrosis, contractures, and calcinosis; patient 2 with diffuse SSc, Raynaud's phenomenon, oedema of the hands, and interstitial calcinosis of hands, knees, and shoulders, and pulmonary fibrosis; patient 3 with scleroderma of hands, forearms, and face, Raynaud's phenomenon, puffy fingers, finger contractures, fingertip necrosis, and calcinosis. All three patients studied were carriers of HLA alleles known to be associated with these autoantibodies. In serial measurements the concentrations of the two antibodies showed independent or even reverse fluctuations. Screening of 100 patients with ACA for ATA and vice versa disclosed no further patients with coincidence of these antibodies. Twenty eight cases of ACA/ATA coexistence in 5423 patients (0.52%) with SSc or SSc associated symptoms were found in an analysis of published studies.

CONCLUSION

The expression of ATA and ACA is not totally mutually exclusive, but coincidence is rare (<1% of patients with SSc). Patients with both autoantibodies often have diffuse scleroderma and show immunogenetic features of both antibody defined subsets of SSc.

Evidence that mycobacterial PE_PGRS proteins are cell surface constituents that influence interactions with other cells

The elucidation of the genomic sequence of Mycobacterium tuberculosis revealed the presence of a novel multigene family designated PE/PE_PGRS that encodes numerous, highly related proteins of unknown function. In this study, we demonstrate that a transposon insertion in a PE_PGRS gene (1818(PE_PGRS)) found in Mycobacterium bovis BCG Pasteur, which is the BCG homologue of the M. tuberculosis H37Rv gene Rv1818c, introduces new phenotypic properties to this BCG strain. These properties include dispersed growth in liquid medium and reduced infection of macrophages. Complementation of the 1818(PE_PGRS)::Tn5367 mutant with the wild-type gene restores both aggregative growth (clumping) in liquid medium and reestablishes infectivity of macrophages to levels equivalent to those for the parent BCG strain. Western blot analysis using antisera raised against the 1818(PE_PGRS) protein shows that PE_PGRS proteins are found in cell lysates of BCG and M. tuberculosis H37Ra and in the cell wall fraction of M. tuberculosis H37Rv. Moreover, immunofluorescent labeling of mycobacteria indicates that certain PE_PGRS proteins are localized at the cell surface of BCG and M. tuberculosis. Together these results suggest that certain PE_PGRS proteins may be found at the surface of mycobacteria and influence both cell surface interactions among mycobacteria as well as the interactions of mycobacteria with macrophages.

Bacterial community associated with Pfiesteria-like dinoflagellate cultures

Dinoflagellates (Eukaryota; Alveolata; Dinophyceae) are single-cell eukaryotic microorganisms implicated in many toxic outbreaks in the marine and estuarine environment. Co-existing with dinoflagellate communities are bacterial assemblages that undergo changes in species composition, compete for nutrients and produce bioactive compounds, including toxins. As part of an investigation to understand the role of the bacteria in dinoflagellate physiology and toxigenesis, we have characterized the bacterial community associated with laboratory cultures of four 'Pfiesteria-like' dinoflagellates isolated from 1997 fish killing events in Chesapeake Bay. A polymerase chain reaction with oligonucleotide primers specific to prokaryotic 16S rDNA gene sequences was used to characterize the total bacterial population, including culturable and non-culturable species, as well as possible endosymbiotic bacteria. The results indicate a diverse group of over 30 bacteria species co-existing in the dinoflagellate cultures. The broad phylogenetic types of dinoflagellate-associated bacteria were generally similar, although not identical, to those bacterial types found in association with other harmful algal species. Dinoflagellates were made axenic, and the culturable bacteria were added back to determine the contribution of the bacteria to dinoflagellate growth. Confocal scanning laser fluorescence microscopy with 16S rDNA probes was used to demonstrate a physical association of a subset of the bacteria and the dinoflagellate cells. These data point to a key component in the bacterial community being species in the marine alpha-proteobacteria group, most closely associated with the alpha-3 or SAR83 cluster.

Neural interfaces for regenerated nerve stimulation and recording

A class of implantable, regeneration-type neural interfaces (NI's) for mammalian peripheral nerve recording and stimulation were developed using different fabrication processes and integrating purposely designed components. A typical NI comprises three main components: 1) a microfabricated silicon die incorporating a microelectrode array on multiple through-holes, 2) a polymer guidance channel housing the die, and 3) a flexible flat cable connecting the die to an external electronic circuitry. The design and fabrication of the NI's were aimed at achieving long term, reliable implants by taking into careful account the biological, electrical, and mechanical requirements of the specific implant site. Different versions of the NI were fabricated and implanted between the severed ends of the sciatic nerve in a mammalian animal model (rabbit). Morphological and histological evidence showed that nerves regenerated through the NI's and electrophysiological results demonstrated the recovery of electrical functionality. Moreover, the NI's allowed stimulation of the regenerated nerve producing a visible leg/foot contraction. The NI's presented in this paper are being further improved in the authors' laboratories with the ultimate goal of allowing the control of nerve motor and sensory functions in future prosthetic devices.

Congenital bilateral coronary-to-pulmonary artery fistulas

Rare, congenital bilateral coronary-to-pulmonary artery fistulas in an older woman, one originating from the proximal right coronary artery and the other from a distal left main coronary artery and draining to the proximal main pulmonary artery, were successfully dissected, identified, and ligated proximally and also closed distally on a beating heart with cardiopulmonary bypass standby.

Identification of a heparin-binding hemagglutinin present in mycobacteria

Adherence to mammalian host tissues is an important virulence trait in microbial pathogenesis, yet little is known about the adherence mechanisms of mycobacteria. Here, we show that binding of mycobacteria to epithelial cells but not to macrophages can be specifically inhibited by sulfated carbohydrates. Using heparin-Sepharose chromatography, a 28-kD heparin-binding protein was purified from culture supernatants and cell extracts of Mycobacterium bovis and Mycobacterium tuberculosis. This protein, designated heparin-binding hemagglutinin (HBHA), promotes the agglutination of rabbit erythrocytes, which is specifically inhibited by sulfated carbohydrates. HBHA also induce mycobacterial aggregation, suggesting that it can mediate bacteria-bacteria interactions as well. Hemagglutination, mycobacterial aggregation, as well as attachment to epithelial cells are specifically inhibited in the presence of anti-HBHA antibodies. Immunoelectron microscopy using anti-HBHA monoclonal antibodies revealed that the protein is surface exposed, consistent with a role in adherence. Immunoblot analyses using antigen-specific antibodies indicated that HBHA is different from the fibronectin-binding proteins of the antigen 85 complex and p55, and comparison of the NH2-terminal amino acid sequence of purified HBHA with the protein sequence data bases did not reveal any significant similarity with other known proteins. Sera from tuberculosis patients but not from healthy individuals were found to recognize HBHA, indicating its immunogenicity in humans during mycobacterial infections. Identification of putative mycobacterial adhesins, such as the one described in this report, may provide the basis for the development of new therapeutic and prophylactic strategies against mycobacterial diseases.

Septate uterus: new idea on the histologic features of the septum in this abnormal uterus

OBJECTIVE

Our purpose was to examine some of the classic concepts about the histologic features of the uterine septum.

STUDY DESIGN

Four biopsy specimens were taken from 16 patients with septate uteri during Tompkins metroplasty: biopsy A from the septum near the serosal layer, biopsy B from the midpoint of the septum, biopsy C from the tip of the septum, and biopsy D from the left posterior aspect of the uterus away from the septum. Thirteen characteristics were examined in these specimens by means of mean ridit analysis and Bonferroni criteria for multiple comparisons in relation to connective tissues (four characteristics), muscles (four characteristics), and vessels (five characteristics).

RESULTS

In the septum the mean ridit score was less for the amount of connective tissues (p < 0.001) and higher for the amount of muscle tissue (p < 0.025), amount of muscle interlacing (p < 0.05), and vessels with a muscle wall (p < 0.005). However, the Bonferroni criterion for multiple comparisons was only significant for the amount of connective tissue (p < 0.001).

CONCLUSION

Our findings of less connective tissue in the septum, which was confirmed by the Bonferroni criterion for multiple comparisons and the mean ridit results for the three other significant findings, were contrary to the classic view about the histologic features of the septum.

Pulmonary complications in lead miners

We carried out a study to assess the prevalence of respiratory disease in lead miners and to investigate the roles of silica and lead. We used a questionnaire for symptoms and examinations for signs of respiratory disease, chest roentgenograms, and spirometric study in 45 lead miners. Six underwent bronchoscopy and transbronchial lung biopsy (TBB) and five lung lead analysis. Lung lead levels from five patients with no occupational lead exposure were obtained for comparison. Results showed restriction in five of 45 and reticulonodular opacities in 16 of 45 workers. Squamous metaplasia and other histopathologic changes were observed, although silicotic nodules were absent by TBB. Lung lead levels above those of control subjects were observed in four of five lead miners. These findings show that lead miners are at risk for lung disease. Although silica is a likely cause, elevated lung lead content found in these miners merits further investigation.

Type Ia tricuspid atresia with extensive coronary artery abnormalities in a living 22 year old woman

Type Ia tricuspid atresia, with extensive coronary artery abnormalities, is identified in the oldest living patient with this condition, a 22 year old woman. Clinical characteristics include severe cyanosis, effort dyspnea, myocardial infarction in the past and persistent angina pectoris. "Ideal" pulmonary flow and adequate left ventricular function, despite an akinetic apical segment, are substantive factors for this exceptional longevity. Coronary abnormalities consist of: 1) total proximal occlusion of the left anterior descending coronary artery; and 2) partial diversion of coronary artery flow to a segmental pulmonary artery branch. Nonvisualization of the coronary sinus is also noted. Factors other than atherosclerosis may account for total proximal occlusion of the left anterior descending coronary artery. Survival is threatened by adverse effects of ongoing ischemic coronary events.

Influx of [3H,14C]cholesterol-labelled lipoprotein into re-endothelialized and de-endothelialized areas of ballooned aortas in normal-fed and cholesterol-fed rabbits

The entry of [3H]- and [3H,14C]cholesterol-labelled lipoprotein into de-endothelialized and re-endothelialized areas of balloon-injured rabbit aortas was studied in normal-fed and cholesterol-fed rabbits. Studies were carried out 11-15 weeks after the initial injury when endothelial regeneration involved approximately half of the aortic area. The entry into the aorta of 3H-labelled free and ester cholesterol in lipoprotein over a 72-h period was studied following the ingestion of a single dose of 3H-labelled cholesterol. The entry of double labelled [3H,14C]cholesterol-labelled lipoprotein was also studied over a 6-h period following the injection of plasma from donor rabbits. The accumulation of cholesterol and cholesterol ester in the aorta in both the normal- and cholesterol-fed rabbits was significantly greater for the re-endothelialized (white) areas than for the de-endothelialized (blue) areas or the sham-operated aortas. Where the rabbits were cholesterol-fed 4-10 times the amount of cholesterol accumulated in re-endothelialized intima compared to normal intima. Both entry (micrograms/day/100 mg wet weight aortic intima) and clearance (mu 1 plasma/day/cm2) of free and ester cholesterol were increased in the neointima compared with the normal intima for both normal-fed and cholesterol-fed rabbits. Hydrolysis of cholesterol ester occurred in the neointima and was greater than in the corresponding de-endothelialized area but less than for the sham-operated intima. Synthesis of cholesterol ester was minimal in all areas. Removal of labelled cholesterol and cholesterol ester from the intima during a 20-h efflux period following the initial 72-h loading period indicated that for aortas of both normal-fed and cholesterol-fed rabbits, there was greater removal for normal intima than for either re-endothelialized or de-endothelialized intima. However, no clear difference between the blue and white areas was observed. It is concluded that the accumulation of cholesterol in neointima after balloon injury is associated with a marked increase in permeability to lipoprotein of the neointima as well as to possible binding of lipoprotein to glycosaminoglycan in the artery.

Glycosaminoglycan composition and biosynthesis in the endothelium-covered neointima of de-endothelialized rabbit aorta

The biosynthesis and composition of glycosaminoglycans (GAG) in the endothelium-covered neointima, formed in response to de-endothelialization of the rabbit aorta by a balloon catheter, was examined. The [14C]glucosamine incorporation into GAG during an in vitro incubation with intimal-medial tissue was monitored periodically up to 24 hr. The GAG were isolated after an exhaustive proteolytic digestion with pronase and protease followed by ethanolic precipitation at 4 degrees C. Electrophoretic migration on cellulose acetate paper was compared for identification. The distribution of GAG was determined after a selective enzymatic digestion of isolated GAG using specific enzymes. Heparan sulfates were estimated after nitrous acid treatment. The concentration of GAG was measured spectrophotometrically by forming colored complexes with Alcian blue dye. In addition, the specific activity (dpm/microgram GAG) and the rate of GAG synthesis (ng/mg dry defatted tissue/day) were determined. The results indicate that the rate of GAG synthesis by de-endothelialized neointima (DEA) was twice that of intact aorta (control). In the re-endothelialized neointima (REA), the GAG synthetic rate was three times more than in control. However, the release of GAG into medium from REA accounts for only 25% of the GAG synthesized by this tissue type, and the release from DEA accounts for 60% of the synthesized GAG. Similarly, a threefold increase in the GAG concentration in REA compared to control was found. The relative distribution as chondroitin-6-sulfate (C6S), chondroitin-4-sulfate (C4S), dermatan sulfate (DS), heparan sulfate (HS) and hyaluronic acid (HA) was markedly altered in the injured neointima. There was an increase in chondroitin sulfates (CS) and DS concomitant with a decrease in HS. It is concluded that injury to aortic endothelium induces stimulation of GAG synthesis in the arterial wall. Furthermore, the greater release of GAG from DEA, compared to control and REA, suggests that endothelium may function as a "reverse" barrier in the neointima covered by regenerated endothelium.

Kinetics of low density lipoprotein interactions with rabbit aortic wall following balloon catheter deendothelialization

The kinetics of the interaction of circulating lipoproteins with the balloon catheter-injured aortic wall of rabbits were investigated. The fate of radioiodinated low density lipoprotein (LDL) was followed up to 48 hours after intravenous injection and compared with radioiodinated albumin injected simultaneously. The accumulation of LDL was calculated from the radioactivity in the aortic tissue divided by the average specific activity, measured from the area below the plasma radioactivity versus the time curve, and expressed as cpm/ml/hr. It was observed that the aortic area of endothelial regeneration (AER), which is relatively impermeable to Evans blue dye and shows very little albumin concentration, accumulated considerably more LDL than control (uninjured) tissues. Furthermore, removal of labeled lipoprotein from the intima during a 24-hour efflux period following the initial 48-hour loading period indicated that there was greater removal from normal and deendothelialized aortic (DEA) tissues than from neointima covered by endothelium. These findings are consistent with previous observations indicating changes in the morphological and chemical composition of AER. There is evidence that greater neointimal lipid accumulation in response to endothelial injury parallels the concentration of glycosaminoglycans (GAG). The relatively increased accumulation of label in AER, while plasma-specific activity is rapidly decreasing, indicates that there may be an ionic interaction of GAG with LDL in the AER.

Lipid composition of rabbit aortic wall following removal of endothelium by balloon catheter

To determine the lipid content of the neointima formed following balloon catheter deendothelialization, we measured the chemical composition of intimal medial samples of the aortic wall of rabbits at 6, 12, and 24 months after the operation. The areas of endothelial regrowth and the denuded areas were outlined by intravenous injection of Evan's blue dye. Lipids were extracted by chloroform/methanol (2:1, vol/vol) separated by thin-layer chromatography, eluted, and estimated by gas-liquid chromatography. No tendency to regression was observed. By contrast we observed a progressive increase over time in the concentration of most lipid classes in the areas of endothelial regrowth. There is evidence indicating that the increase in the lipid concentration parallels the increase in the glycosaminoglycan content in the areas of endothelial regrowth. It is possible that endothelial injury causes some irreversible changes in the composition of the neointima in areas of endothelial regeneration.

3-Hydroxy-3-methylglutaryl CoA reductase in cultured hepatocytes. Regulation by heterologous lipoproteins and hormones

Regulation of the key enzyme of cholesterol synthesis, 3-hydroxy-3-methylglutaryl CoA reductase (EC: 1.1.1.34), by heterologous human lipoproteins and hormones was studied in a maintenance culture of rat hepatocytes. The liver cells were cultured under hormone and serum free conditions and maintained differentiated morphology and specific function. Under control conditions total HMG-CoA reductase increased by 50% after 24 h culture compared to 0 h values immediately after isolation. Thereafter a plateau of enzyme activity was reached lasting until 48 h, with a slight decline at 72 h. Concomitantly the "expressed" enzyme activity increased steadily, probably through dephosphorylation of latent reductase, the activation was largely complete at 48 h. During the steady state period of total reductase VLDL added to the medium at concentrations up to 50 microgram/ml protein had no effect o HMG-CoA reductase activity. In contrast, LDL suppressed the enzyme in a dose-dependent fashion to 40% of controls at 100 microgram/ml. On the other hand, HDL had the opposite effect with a significant induction up to 252% of controls at 50 microgram/ml. Insulin also caused a comparable dose-dependent stimulation of enzyme activity at 10(-8) and 10(-7)M, whereas glucagon inhibited reductase activity. Compared to the insulin action, triiodothyronine and triamcinolone prompted a minor, but still significant increase of reductase activity. Insulin and triamcinolone acted synergistically, but the combination of triamcinolone and tri-iodothyronine was only additive. All hormonal inductions of reductase could be blocked by cycloheximide. The present data establish that HMG-CoA reductase of maintenance cultured hepatocytes is subject to a complex regulation by heterologous lipoproteins as well as pancreatic, adrenal and thyroid hormones.

Regulation of 3-hydroxy-3-methylglutaryl CoA reductase by analogs of cholesterol and bile acids in cultured intestinal mucosa

Sodium fusidate and its glycine conjugate, which have the same detergent properties as bile acids, significantly (p less than 0.05) stimulate HMG-CoA reductase of cultured intestine below the critical micellar concentration (CMC) without affecting brush border enzymes. Above CMC, both amphiphiles are cytotoxic. At concentrations between 1 and 5 mM, sodium fusidate decreased cholesterol contents of cultured mucosa (P less than 0.05), the increase in synthesis only partially compensating for the sterol loss. Oxygenated sterols, 7-keto- and 25-hydroxycholesterol, also depleted mucosal cholesterol at 0.5 mM, exerting their effect differently by inhibiting HMG-CoA reductase (p less than 0.01). In contrast to their marked effect on total mucosal cholesterol contents, brush border cholesterol was unaffected by both cholesterol and bile acid analogs.

Regulation of 3-hydroxy-3-methylglutaryl-CoA reductase by endogenous sterol synthesis in cultured intestinal mucosa

In vitro regulation of the key enzyme of cholesterol synthesis, 3-hydroxy-3-methylglutaryl-CoA reductase (EC 1.1.1.34) by compactin, a competitive inhibitor of the enzyme, and mevalonate was studied in rabbit ileum organ culture. Addition of compactin suppressed ileum homogenate reductase activity by over 80% at concentrations up to 0.5 microgram/ml. In contrast, compactin at the same concentrations added to the culture medium induced reductase activity up to 240% of controls. This increase was blocked by cycloheximide and mevalonolactone at 10 mM, but not by mevalonate (salt form) and cholesterol. Similarly, in contrast to ionized mevalonate, mevalonolactone significantly suppressed reductase activity of cultured intestine at 1 and 10 mM by 23 and 62%, respectively. A minor effect was also observed with preformed enzyme in fresh mucosal homogenate. When endogenous cholesterol synthesis was blocked by compactin, mucosal alkaline phosphatase activity decreased progressively, whereas medium activity from desquamated cells did not change. This distribution of the villous cell marker enzyme is characteristic of a decrease in crypt cell renewal and/or villous cell differentiation. This effect of compactin was also reversible with mevalonolactone. The reductase enzyme induced by compactin was probably latent intracellularly, since tissue cholesterol contents dropped sharply after blockade of endogenous sterol synthesis.

Influence of dietary cholesterol, saturated and unsaturated lipid on 3-hydroxy-3-methylglutaryl CoA reductase activity in rabbit intestine and liver

To characterize further the behavior of the rate-limiting enzyme of cholesterol biosynthesis in animal species, we studied the kinetic properties and the influence of dietary lipid on intestinal and hepatic HMG-CoA reductase activity in the rabbit. In intestinal crypt and villous cells isolated by a dual buffer technique, the KM value was 4.2 and 4.6 microM, respectively for DL-HMC-CoA. The specific activity of HMG-CoA reductase in the jejunum was 0.86 nmol/mg per hr, and evenly distributed between crypt and villous cells. By contrast, reductase activity was considerably lower in the ileum: in villous cells it was 0.40 nmol/mg per hr, and in crypt cells only 0.26 nmol/mg per hr. Liver microsomes had a KM value of 3.0 microM, while the reductase activity averaged 2 nmol/mg per hr. An unexpected finding was the uneven distribution of HMG-CoA reductase in the various lobes of the liver in the single animal. The addition of 1% cholesterol to the diet for 48 hours was followed by an average decline of 73% (P less than 0.005) of HMG-CoA reductase activity in villous and crypt cells of the jejunum. In the ileum, the decrease was less marked (38%, P less than 0.01). Whereas the addition of 5% corn oil to a 1% cholesterol diet did not have an additional suppressant effect on intestinal reductase, the addition of 5% coconut oil to 1% cholesterol caused further decrease of HMG-CoA reductase in jejunum and ileum (P less than 0.05). The 1% cholesterol diet resulted in a 25% decrease of hepatic reductase after 24 hours, whereas after 6 days, the enzyme activity was reduced by 90% of normal. Both 5% corn oil or 5% coconut oil, in addition to 1% cholesterol, further suppressed hepatic reductase activity. The weight of the experimental evidence presented in these studies suggests that cholesterol has a major regulatory effect on both intestinal and hepatic reductase in the rabbit.

Lipoprotein regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase in cultured intestinal mucosa

In vitro regulation of the key enzyme of cholesterol synthesis, 3-hydroxy-3-methylglutaryl-CoA reductase (EC 1.1.1.34), was studied in 24-h organ culture of rabbit ileum. Preincubation of mucosal homogenate in phosphate buffer increased apparent reductase activity more than 5-fold. The activation was blocked in the presence of 150 mM NaF, suggesting interconversion of latent reductase by dephosphorylation. No significant further activation was achieved by potato phosphatase treatment. During culture total reductase activity was stimulated by 125% in lipoprotein-free medium. Addition of low density lipoprotein to the medium resulted in a dose-dependent suppression of reductase activity between 0.2 and 1.0 mM lipoprotein cholesterol. At these concentrations LDL inhibition reached 51 and 75% of control, respectively. The reductase response to very low density and high density lipoproteins was biphasic, with a 2- to 3-fold stimulation at 0.1-0.3 mM and a suppression at higher levels. No such stimulation was observed with high density lipoproteins obtained from cholesterol fed animals. Similarly, 'hypercholesterolemic' very low density lipoproteins enhanced reductase activity only slightly. It is concluded that lipoproteins are potent regulators of cholesterol synthesis in cultured intestine.