Risk Factors and predictors of human immunodeficiency virus infection among injection drug users

BACKGROUND/AIM: Injection drug users (IDUs) have a high risk of acquiring an infection with the human immunodeficiency virus (HIV). To improve counseling and prevention, a better understanding of risk factors and predictors for an infection must be gained. This retrospective study has the aim to determine the risk factors for acquisition of HIV infection other than sharing of needles/syringes. METHODS: The study population consisted of all patients admitted to the detoxification unit between 1991 and 1996 who met ICD-10 criteria for opioid dependency, who reported to share needles, and who agreed to have an antibody test. Possible risk factors were assessed by interview. Cross tables based on bivariate logistic regression were constructed to estimate the relative odds. Multiple logistic regression modeling procedures were used to adjust possible confounding factors. RESULTS: A total of 1,049 out of 1,656 patients admitted were included into the study. 4.8% of the patients were HIV-1 seropositive. The prevalence was higher among older patients and among patients living with a significant other substance drug user with substance dependency, after a longer duration of drug use, and after coinfection with hepatitis B virus and/or hepatitis C virus (HCV). Using multiple logistic regression analyses and including all individually significant risk factors, we found only coinfection with HCV to remain significant. 92% of the HIV-infected patients were also HCV infected. In the group younger than 23 years of age, a total of 53.5% of the IDUs were still seronegative for HIV, hepatitis A and B virus, and HCV. CONCLUSIONS: Despite the high rate of HCV coinfection (92%) in HIV-infected patients, we found more than 50% of IDUs younger than 23 years to be neither infected with HCV nor with HIV. Early prevention strategies against infectious diseases should especially focus on young IDUs.     

Feasibility and safety of peripheral blood stem cell transplantation from unrelated donors: results of a single-center study

We compared the outcomes in patients receiving unrelated peripheral blood stem cell transplants (PBSCT) with those receiving bone marrow transplants (BMT) in a matched pair analysis. Seventy-four patients with hematological malignancies with HLA-matched (77%) and mismatched (23%) donors were analyzed in this study. Thirty-four patients (45%) were considered as high risk patients. Sixty-eight patients received standard conditioning regimens with Bu/Cy or TBI/Cy. Six patients received an intensified conditioning regimen with the addition of etoposide, thiotepa or melphalan. GVHD prophylaxis consisted of prednisolone, cyclosporine and methotrexate. Groups were matched for patient, donor, transplant characteristics and HLA compatibility. Peripheral blood stem cell collection led to the collection of a higher number of CD34+ and CD3+ cells in comparison to bone marrow collection. Leukocyte engraftment in the PBSCT group occurred in 14 days (median; range 6-26 days) and in the BMT group in 19 days (range 9-29 days; P < 0.02). The time of platelet engraftment did not differ significantly. The incidence of grades II-lV acute GVHD in the group of HLA-identical patients was 35% in the PBSCT group and 25% in the BMT group (P < 0.33, log-rank). However, there was a significant difference (P < 0.05, log-rank) in incidence and time to onset of acute GVHD II-IV comparing all patients, including the 17 mismatched transplants. Disease-free survival was 51% (19 patients) with a median of 352 days and 59% (21 patients) with a median of 760 days for PBSC and BMT transplants, respectively. In conclusion, our results indicate that allogeneic PBSCT led to significantly faster leukocyte engraftment but is associated with a higher incidence and more rapid onset of severe acute GVHD comparing all patients, including the 17 mismatched transplants. However, the incidence of severe acute GVHD in HLA-identical patients was not different between the PBSCT and BMT groups.     

Tridimensional activation patterns of acquired torsade-de-pointes-tachycardias in dogs with chronic AV-block

Abstract. Background: Dogs with chronic AV block exposed to type-III antiarrhythmic agents develop polymorphic ventricular tachycardias (PVT). Controversy exists regarding PVT mechanism and underlying pathophysiology. Methods and Results: In dogs with acute (n = 10, AAVB) or chronic AV block (n = 14, CAVB, 62 ± 5 days after AV-node ablation) 60 pins (12 mm long, 4 bipolar electrodes) were inserted into both ventricles. QT intervals and effective refractory periods (ERP) at 56 ± 22 randomly selected sites (extrastimulus technique, 800 ms basic cycle length) were determined before and after Almokalant (0.34 mol/kg). A multiplexer mapping system was used to reconstruct 3D activation patterns. The heart-to-body-weight index (HBWI) was obtained after the experiments. CAVB led to a significant increase in HBWI (11.3 ± 1.5 vs. 9 ± 1.2 g/kg BW, p < 0.001), and a significant increase in ERP (280 ± 28 ms vs. 260 ± 37 ms, p < 0.05) and QT interval (339 ± 16 vs. 288 ±12 ms, p < 0.05). Dispersion (DISP) of ERP was similar for AAVB and CAVB dogs. No AAVB dog, but 9 of 14 CAVB dogs developed PVTs in response to Almokalant. All PVTs originated from an endocardial focus. Consecutive beats continued to reveal centrifugal activation patterns in 8 of 10 episodes. In only 2 episodes was reentrant activation evident. Conclusion: Myocardial hypertrophy associated with CAVB predisposes the canine heart to druginduced PVTs. This seems to be primarily linked to prolonged repolarization. PVTs in this model are not only initiated, but also perpetuated by a centrifugal spread of activation.     

Schistosoma japonicum reveals distinct reactivity with antisera directed to proteases mediating host infection and invasion by cercariae of S. mansoni or S. haematobium

Serine proteases released from the acetabular glands of cercariae, also known as cercarial elastases, are key enzymes in the penetration process of schistosomes through the skin of the final host. Antisera against these enzymes secreted from Schistosoma mansoni or S. haematobium reveal differences in the patterns of elastase expression among schistosome species and among different developmental stages of the larvae. Immunolocalization studies showed that antisera raised against the enzyme s28 protease react with S. mansoni, S. haematobium and also S. japonicum, in developing as well as mature cercariae and in both pre- and post-acetabular glands. Antisera against the enzyme SmCE detect the respective antigen solely in the pre-acetabular glands. Remarkably, the SmCE-1a isoform is detectable with DNA-vaccinated mouse sera in S. mansoni and S. haematobium only, but is apparently absent from the acetabular glands of S. japonicum. These differences in immunoreactivity of cercarial enzymes may be related to the distinct infection process of S. japonicum.     

Cartilage atrophy in the knees of patients after seven weeks of partial load bearing

OBJECTIVE: It is currently unknown whether human cartilage properties change during short periods of partial load bearing. We used a post-ankle fracture model to explore whether changes in cartilage morphology occur in the knee under conditions of partial load bearing. METHODS: The knees of 20 patients with Weber type B and type C fractures were examined using magnetic resonance imaging. The first scan was obtained shortly (mean +/- SD 3.2 +/- 3.0 days) after the injury, and a second scan was obtained 7 weeks later (mean +/- SD 50.7 +/- 5.5 days). The morphology (mean and maximum thickness, volume, and surface area) of the patellar, tibial, and femoral cartilage was determined from coronal and axial magnetic resonance images (fat-suppressed gradient-echo). RESULTS: Between week 0 and week 7, the cross-sectional area of the quadriceps muscle was reduced by 11% (P< 0.001). Changes in the mean (+/-SD) cartilage thickness ranged from -2.9 +/- 3.2% in the patella to -6.6 +/- 4.9% in the medial tibia. No significant change in cartilage morphology of the contralateral knee was observed. CONCLUSION: Results of this study demonstrate that in a post-ankle fracture model of partial load bearing, cartilage morphology in all knee compartments is subject to significant change. Changes in the femorotibial joint exceeded those in the patella, whereas no change was observed in the contralateral knee. These findings raise the question of whether cartilage is mechanically less competent and particularly vulnerable after states of partial or complete immobilization.     

Magnetic resonance imaging-based assessment of cartilage loss in severe osteoarthritis: accuracy, precision, and diagnostic value

OBJECTIVE: To examine the in vivo accuracy and precision of magnetic resonance imaging (MRI)-based assessment of cartilage loss in patients with severe osteoarthritis (OA) of the knee. METHODS: High-resolution MRI images of the tibial cartilage were obtained in 8 patients prior to total knee arthroplasty, using a water-excitation gradient-echo MRI sequence (acquisition time 6 minutes 19 seconds; spatial resolution 1.2 x 0.31 x 0.31 mm3). The MRI measurements were repeated after joint repositioning. The precision of the cartilage volume and thickness computations was determined after 3-dimensional reconstruction. During surgery, the tibial plateaus were resected, and the MRI data were compared with water displacement of surgically retrieved cartilage. RESULTS: The standard deviation (coefficient of variation) of repeated tibial cartilage volume measurements was 56 mm3 (5.5%) medially and 59 mm3 (3.8%) laterally. The deviation from surgically removed tissue was -13%, on average, with a high linear correlation between both methods (r = 0.98). In patients with varus OA, the tissue loss was estimated to be 1,290 mm3 in the medial tibia and 1,150 mm3 in the lateral tibia, compared with the data in healthy volunteers. CONCLUSION: Noninvasive quantitative MRI-based analysis of cartilage morphometry in severe OA is accurate, precise, and displays high potential diagnostic value.     

A total of 1,007 percutaneous coronary interventions without onsite cardiac surgery: acute and long-term outcomes.

OBJECTIVES: We sought to compare clinical outcomes of elective percutaneous coronary intervention (PCI) and primary PCI for ST-segment elevation myocardial infarction (STEMI) at a community hospital without onsite cardiac surgery to those at a tertiary center with onsite cardiac surgery. BACKGROUND: Disagreement exists about whether hospitals with cardiac catheterization laboratories, but without onsite cardiac surgery, should develop PCI programs. Primary PCI for STEMI at hospitals without onsite cardiac surgery have achieved satisfactory outcomes; however, elective PCI outcomes are not well defined. METHODS: A total of 1,007 elective PCI and primary PCI procedures performed from March 1999 to August 2005 at the Immanuel St. Joseph's Hospital-Mayo Health System (ISJ) in Mankato, Minnesota, were matched one-to-one with those performed at St. Mary's Hospital (SMH) in Rochester, Minnesota. Strict protocols were followed for case selection and PCI program requirements. Clinical outcomes (in-hospital procedural success, death, any myocardial infarction, Q-wave myocardial infarction, and emergency coronary artery bypass surgery) and follow-up survival were compared between groups. RESULTS: Among 722 elective PCIs, procedural success was 97% at ISJ compared with 95% at SMH (p = 0.046). Among 285 primary PCIs for STEMI, procedural success was 93% at ISJ and 96% at SMH (p = 0.085). No patients at ISJ undergoing PCI required emergent transfer for cardiac surgery. Survival at two years' follow-up by treatment location was similar for patients with elective PCI and primary PCI. CONCLUSIONS: Similar clinical outcomes for elective PCI and primary PCI were achieved at a community hospital without onsite cardiac surgery compared with those at a tertiary center with onsite cardiac surgery using a prospective, rigorous protocol for case selection and PCI program requirements.     

Thoracic insufficiency syndrome in patients with fibrodysplasia ossificans progressiva

Patients with fibrodysplasia ossificans progressiva (FOP) develop thoracic insufficiency syndrome (TIS), which can lead to life-threatening complications. Features contributing to TIS in patients with FOP include costovertebral malformations with orthotopic ankylosis of the costovertebral joints; ossification of intercostal muscles, paravertebral muscles, and aponeuroses; and progressive spinal deformity, including kyphoscoliosis or thoracic lordosis. Pneumonia and right-sided congestive heart failure are the major life-threatening hazards that result from TIS in patients with FOP. Prophylactic measures to maximize pulmonary function, minimize respiratory compromise, and prevent influenza and pneumonia may be helpful in decreasing the morbidity and mortality from TIS in patients with FOP.     

Fibrin-Blood Platelet Interaction in a Contracting Clot

The interaction of fibrin and blood platelets was studied by measuring tension development in clots containing different ratios of these two components. Isometric tension attained a saturating value (MT) when plotted as a function of the concentration of either component at a constant concentration of the other. The value of MT increases linearly with the minimal platelet concentration (Ps) required in order to reach saturation at various different fibrin concentrations. A linear relationship also holds in a plot of Ps versus the logarithm of the corresponding fibrin concentration. When the cylindrical clots contracted isotonically, the velocity, normalized with respect to the momentary length, was found to be constant. This velocity decreased in an hyperbolic manner with increasing fibrin concentration at a constant concentration of blood platelets. The results are interpreted in terms of a three-dimensional network in which the blood platelets serve as contractile cross-bridges connecting fibrin fibres. Tension development is assumed to be accompanied by the reduction of the angle between fibrin fibres. An attempt was made to calculate the isometric tension developed by a platelet.