A synchrotron computed tomography dataset for validation of longitudinal tensile failure models based on fibre break and cluster development

We performed in-situ tensile tests on two carbon fibre/epoxy composites with continuous scanning using synchrotron computed tomography (CT). Both composites were cross-ply laminates, and two specimens were tested for each composite. The voxel size was sufficiently small to recognize individual fibres and fibre breaks. For each test, 16-19 volumes were reconstructed, cropped down to the 0° plies and analysed to track fibre break and cluster development. This dataset provides the last CT volume before failure for each of the four specimens as well as the individual fibre break locations in all reconstructed volumes. These data are then plotted against predictions from six state-of-the-art strength models. The target is that these data become a benchmark for the development of new models, inspiring researchers to set up refined experiments and develop improved models.

A randomised, double-blind study comparing the efficacy and tolerability of controlled-release doxazosin and tamsulosin in the treatment of benign prostatic hyperplasia in Brazil

Brazilian patients with benign prostatic hyperplasia were randomised in a 12-week, double-blind, double-dummy study to receive doxazosin gastrointestinal therapeutic system (GITS) 4 mg q.i.d. (n = 82) or tamsulosin 0.4 q.i.d. (n = 83). Primary endpoints were the absolute and percentage change from baseline in symptoms measured by International Prostate Symptom Score (IPSS). Secondary endpoints included IPSS, quality-of-life (QOL) question from the IPSS, and questions 6 and 7 of the Sexual Function Abbreviated Questionnaire (SFAQ) at weeks 4 and 12. Doxazosin GITS and tamsulosin improved IPSS with no significant differences between groups at week 12. During weeks 4-8, tamsulosin-treated patients demonstrated a slower improvement (p < 0.001) in IPSS than doxazosin GITS-treated patients. The proportion of satisfied patients was observed earlier with doxazosin GITS (p = 0.006) vs. tamsulosin. At week 12, the proportion of patients with little or no difficulty at ejaculation (Q6 of SFAQ) was higher in the doxazosin GITS group (p = 0.019). Both treatments were well tolerated.

Overdoses among cocaine users in Brazil

AIMS

A survey of cocaine users was undertaken to study (i) the frequency of reported drug overdoses among cocaine users; and (ii) the frequency of witnessing drug overdoses in the same population.

DESIGN AND SETTING

A cross-sectional study as part of the World Health Organization (WHO) Multi-city Study among injecting drug users (IDUs), phase II, was conducted in Santos Metropolitan Region, State of São Paulo, Brazil, in 1999.

PARTICIPANTS

Three hundred and ninety-six exclusive users of cocaine in the Santos Metropolitan Region, São Paulo State, Brazil were surveyed concerning their past experience with drug overdoses.

FINDINGS

Eighty (20%) of the cocaine users reported having experienced one or more overdoses, and 50% reported that they knew one or more other cocaine users who had died of an overdose. On multivariate analysis, being female and having spent time in jail were associated with an increased likelihood of having had one or more overdoses.

CONCLUSION

Cocaine overdoses are an important and under-recognized health problem in the Santos Metropolitan Region, and possibly in other areas of Brazil.

Trends of HIV infection among injection drug users in Brazil in the 1990s: the impact of changes in patterns of drug use

BACKGROUND

Santos Metropolitan Region (SMR), State of Sao Paulo, historically is well known as being one of the areas with the largest number of AIDS cases in Brazil, especially among injection drug users (IDUs). The main objective of this study was to assess the effects of changes in drug-using patterns among IDUs on trends in HIV infection among IDUs in the 1990s.

METHODS

During 1991 through 1992 (wave 1; n = 214), 1994 through 1996 (wave 2; n = 135), and 1999 (wave 3; n = 108), we conducted three cross-sectional studies of IDUs. All participants were interviewed and tested for antibodies to HIV.

FINDINGS

The overall sample population was 69% male, and 87% of the sample population was under 40 years old. Eighty-four percent of the population had less than 9 years of education. HIV seroprevalence was 63% in wave 1, 65% in wave 2, and 42% in wave 3 ( p <.001). Smoking of crack cocaine increased from 11% in wave 1 to 60% in wave 2 and 67% in wave 3 ( p <.001). The prevalence of frequent injections (>5 per day) decreased from 42% in wave 1 to 30% in wave 2 and 15% in wave 3 ( p <.001).

INTERPRETATION

HIV prevalence decreased as injection frequency decreased and crack cocaine use increased. In SMR, patterns of drug use have been affecting the HIV epidemic more than scant public health intervention.

The effect of calcium channels blockers in the K+-evoked release of [3H]adenine nucleotides from rat brain cortical synaptosomes

The role of L-,N-, P- and Q-type voltage-dependent calcium channels in K+-induced release of [3H]adenine nucleotides from rat brain cortical synaptosomes was investigated. Cd2+, a non-specific blocker of calcium channels, inhibited by 69% the release of the nucleotides induced by 33 mM K+. Nifedipine, omega-Conotoxin GVIA and omega-Agatoxin IVA had no effect whereas omega-Conotoxin MVIIC inhibited by 62% the K+ induced release of adenine nucleotides in rat brain cortical synaptosomes. It is concluded that Q-type calcium channels are directly involved in the release of adenine nucleotides in rat brain cortical synaptosomes.

[Value of "cardiac event recorders" in the assessment of sporadic cardiac symptoms]

OBJECTIVES

To determine the value of the Cardiac Event Recorder (CER) in the diagnosis and treatment orientation of bradydysrhythmias, tachydysrhythmias and ischaemic events, based on our experience at the Santa Cruz Hospital.

METHODS

We retrospectively analysed 100 consecutive patients tested with a CER between January 1990 and December 1996 (mean follow-up, 272 +/- 202 days); the mean age of the patients (66 women and 34 men) was 45 +/- 18 years (range: 7 to 83); structural cardiac disease was present in 34% of the patients. CER was indicated for the investigation of symptoms suggestive of bradydysrhythmias (pre-syncope and/or syncope)--Group B--in 24 patients, tachydysrhythmias (palpitations and/or tachycardia sensation)--Group T--in 72 patients and ischaemic events--Group I--in the remaining four patients. We compared these groups with respect to demographic characteristics, prevalence of structural cardiac disease and efficacy of the test in the investigation of symptoms; periodicity of symptoms and duration of CER testing were analysed. In patients that experienced typical symptoms during the test, we analysed the electrocardiogram recorded at the time of the event and we investigated whether abnormal ECG findings influenced the therapeutic approach and whether this led to better symptomatic outcome.

RESULTS

Patients in groups B and T were mainly women (54 percent vs 74 percent, NS). Group B patients were older than group T patients (mean age, 56.4 +/- 17.8 vs 40.0 +/- 16.0 yrs, P < 0.001). In group B, structural cardiac disease was less prevalent (37.5% vs 78.0%, P < 0.001) and symptom periodicity was greater (weekly: 12.5% vs 78.0%, monthly: 87.5% vs 15.2%, P < 0.001) than in group T. Duration of CER testing and number of events recorded were similar in the two groups. In both, CER testing was an important aid for therapeutic approach. Twenty two patients (eight B, 13 T and one I) had no typical symptomatic episodes during the CER test; in the remaining 78 patients (16 B, 59 T and three I), an electrocardiogram recording during such episodes was available for analysis. The ECG was abnormal in 44 of these patients, 12 (75%) being of group B and 32 (54%) of group T. Symptom periodicity was a few weeks in 65% of all patients (6 B, 57 T and two I). Duration of CER testing was < or = two weeks in 91 percent of the patients (22 B, 65 T and four I). CER testing guided the therapeutic approach in 78% of all patients. Changes of treatment strategy were more frequent in patients with CER documented typical symptomatic episodes than in those without (46% vs 9%, P < 0.02). When changes of treatment occurred, symptomatic outcome was better (97% vs 55%, P < 0.001).

CONCLUSIONS

The CER is an important guide for the diagnostic and therapeutic approach for patients with intermittent arrhythmia suggesting, symptoms (78% of patients). A recording of normal ECG during typical symptoms reassures the patient and excludes potentially toxic treatments. Our selection of patients for CER testing seemed adequate since most typical symptomatic events occurred during the first two weeks of the test; longer duration of CER testing seems unnecessary.

HIV and infections of similar transmission patterns in a drug injectors community of Santos, Brazil

To study the prevalence of HIV and infections with related transmission patterns, we interviewed and obtained blood samples from 220 injecting drug users (IDUs), sampled by snowballing, from the city of Santos in the state of São Paulo, Brazil, where the estimated number of IDUs (10,000) comprises approximately 2% of the entire population. Seroprevalence of HIV, hepatitis B and C, syphilis, and HTLV (1 and 2) was assessed and compared with that in 197 blood donors from the same city, matched for age and gender. Risk behavior related to HIV was assessed by a standard questionnaire applied to the IDU sample. Univariate and multivariate analyses of the risk factors were performed. Seroprevalences found were 62% for HIV, 75% for HCV, 75% for HBV, 34% for syphilis, and 25% for HTLV (1 and 2) among IDUs, which compare with 0.0%, 2%, 23%, 12%, and 1% for blood donors, respectively. The risk for parenterally transmitted infections in this IDU community was higher than that for sexually transmitted infections (odds ratio for syphilis, 3.57; hepatitis B, 10.0; and hepatitis C, 100). The results of the mutivariate risk analysis showed that daily rate of ID use >5 times/day (OR = 6.73), not changing behavior to avoid AIDS (OR= 3.28), ID use >15 days/month (OR = 2.72), and ID use in the last 2 months (OR = 2.23) were the risk behaviors significantly associated with HIV infection.

The basic reproduction ratio of HIV among intravenous drug users

A new approach for the estimation of the Basic Reproduction Ratio R0 for HIV among intravenous drug users (IVDU) is proposed. This approach is based in an adaptation of the models proposed by Ross and Macdonald for vector-borne infections. A straightforward adaptation of Macdonald's model is presented first: biological vectors are replaced by needles and syringes and we consider a homogeneous population of IVDUs; next we present a modified model where several heterogeneities are considered. Some of those heterogeneities are due to intrinsic differences between needles and syringes and biological vectors; others, such as those related to movements of individuals between communities, should apply to both biological vectors and injection apparatuses. An example of the calculations of R0 for a real IVDUs community is presented.