Self-reported comorbidities,perceived needs,and sources for usual care for older and younger homeless adults

BACKGROUND: While older individuals who are homeless tend to be in poorer health, it is less clear how they view their health care needs and whether their self-reported patterns for accessing health services differ from younger homeless counterparts. METHODS: Cross-sectional, community-based survey of homeless adults in Pittsburgh and Philadelphia using face-to-face interviews from population proportionate sampling of sites and random sampling of subjects. Survey questions included physical and mental health comorbidities, self-reported health care, social services and personal needs, means of economic support, and sources for usual health care. For analysis purposes, respondents were grouped by age 18 to 49 years old and 50 years old or older. RESULTS: Overall, 531 adults were interviewed, with 74 respondents 50 years old or older (13.9%). Older homeless persons were 3.6 times more likely to report a chronic medical condition, 2.8 times more likely to have health insurance, and 2.4 times more likely to be dependent on heroin than homeless persons less than 50 years old. However, they also tended to use shelter-based clinics and street outreach teams more commonly as their source of usual care (20.9% vs 10.6%, P=.02) and were significantly less likely to report a need for substance abuse treatment despite high rates of abuse. CONCLUSION: Older homeless adults have a greater disease burden than their younger counterparts. However, it is unclear whether these needs are being appropriately identified and met. There is a need for specific and targeted outreach to connect them to appropriate services.     

HIV type 1 CRF13_cpx revisited: identification of a new sequence from Cameroon and signal for subsubtype J2

A nearly full-length genome sequence of an HIV-1 isolate originating from Cameroon, 02CM.3226MN, was found to cluster together with previously reported CRF13 sequences 96CM-4164 and 96CM-1849. Similarity plotting, bootscanning, breakpoint analysis, and phylogenetic trees confirmed similar genomic structures with almost identical breakpoint positions among these three isolates. Thus, CRF13 now fulfills the HIV-1 nomenclature requirements. A X2 analysis across all three genomes simultaneously was applied to more accurately determine breakpoints and address the uncertainty in such estimates. Some fragments were found to be difficult to classify, as indicated by a low branching index (BI), due to limited knowledge about parental and reference subtype sequences. One fragment with low BI association to reference subtype J sequences (BI = 0.27, cut-off for subtype classification >0.55) was found to be closer to J fragments of CRF11 similar to the way that A1-A2 and F1-F2 subsubtypes associate. This suggests that subtype J may need to be reclassified into subsubtypes J1 and J2. The CRF13 genome consists of fragments from subtypes A1, G, and both J1 and J2 as well as CRF01 and one region that was left unclassified.     

Use of experimental crystallographic phases to examine the hydration of polar and nonpolar cavities in T4 lysozyme

There is conflicting evidence as to whether cavities in proteins that are nonpolar and large enough to accommodate solvent are empty or are occupied by disordered water molecules. Here, we use multiple-wavelength x-ray data collected from crystals of the selenomethionine-substituted L99A/M102L mutant of T4 lysozyme to obtain a high-resolution electron density map free of bias that is unavoidably associated with conventional model-based structure determination and refinement. The mutant, L99A/M102L, has four cavities, two being polar in character and the other two nonpolar. Cavity 1 (polar, volume 45.2 ų) was expected to contain two well ordered water molecules, and this is confirmed in the experimental electron density map. Likewise, cavity 2 (polar, 16.9 ų) is confirmed to contain a single water molecule. Cavity 3 (nonpolar, 21.4 ų) was seen to be empty in conventional x-ray refinement, and this is confirmed in the experimental map. Unexpectedly, however, cavity 4 (nonpolar, volume 133.5 ų) was seen to contain diffuse electron density equivalent to ≈1.5 water molecules. Although cavity 4 is largely nonpolar, it does have some polar character, and this apparently contributes to the presence of solvent. The cavity is large enough to accommodate four to five water molecules, and it appears that a hydrogen-bonded chain of three or more solvent molecules could occupy the cavity at a given time. The results are consistent with theoretical predictions that cavities in proteins that are strictly nonpolar will not contain solvent until the volume is large enough to permit mutually satisfying water–water hydrogen bonds.     

Analysis of exercise-induced changes in R wave amplitude in asymptomatic men with electrocardiographic ST-T changes at rest

Fifty asymptomatic men, 44 (88 percent) of whom were pilots or allied aviation personnel, were referred because of resting ST-T electrocardiographic changes indistinguishable from those of myocardial ischemia. Because of the nature of their occupations, cardiac catheterization was performed to establish the presence or absence of coronary artery disease. Exercise tests were performed and analyzed retrospectively with respect to exercise-induced changes in the S-T segment and R wave amplitude. The results were correlated with coronary angiographic and echocardiographic findings.The 50 subjects were classified into two groups: Group I, 5 men with angiographically proved coronary artery disease, and Group II, 45 men without significant coronary arterial obstruction. Analysis of the S-T segment changes at peak exercise showed 21 subjects (42 percent) with a positive exercise test and 29 (58 percent) with a negative test. All subjects in Group I had a positive test. Sixteen subjects (35 percent) in Group II had a false positive result. Analysis of exercise-induced changes in R wave amplitude revealed that six subjects had a positive R wave response on the basis of sum of the changes in voltage in the leads measured (Δ∑R). Four of the six subjects had coronary artery disease and the other two were thought to have a cardiomyopathy. One subject with coronary artery disease had a negative R wave response. Echocardiography revealed five subjects with asymmetric septal hypertrophy; two of these had a positive exercise test and three a negative test on the basis of S-T segment criteria.Thus, symptom-limited treadmill exercise testing of asymptomatic men with resting ST-T electrocardiographic changes produced a high incidence rate of false positive results when S-T segment criteria were used, whereas analysis of changes in R wave amplitude yielded only two false positive results, both in men who had evidence of other heart disease.     

Recognizing and improving patient nonadherence to statin therapy

Despite landmark trials demonstrating the benefits of statin therapy for lipid lowering and in the primary and secondary prevention of acute coronary events, many patients do not adhere to medication regimens. Although incremental gains have been made in lowering the absolute levels of total serum cholesterol in the general population, only one third of treated patients are achieving their lipid goals, with fewer than 20% of patients with cardiovascular disease at their target lipid goals. Only half of patients continue taking statins prescribed to them at 6 months, and only 30% to 40% continue taking them at 1 year. Predictors of poor adherence to statins are described, such as female gender and low socioeconomic status. Approaches that are physician focused and patient centered, such as frequent follow-up and serum lipid testing and better education of patients about cardiovascular disease, are suggested to offset a major impediment to achieving the full therapeutic outcomes promised by clinical trials.     

Orthodeoxia-platypnea due to intracardiac shunting relief with transcatheter double umbrella closure

The safety and efficacy of transcatheter clamshell occlusion of patent foramen ovale for relief of severe arterial desaturation and dyspnea in the upright position due to intracardiac shunting were examined in eight patients with excessive risk of surgical patent foramen ovale closure. All patients had successful reduction of intracardiac shunting with an immediate rise in oxygen saturation ?95% by implantation of a clamshell device on the atrial septum. Despite two early incidents of device embolization, retrieval and immediate re-implantation, and one patient with nonsustained atrial and ventricular arrhythmias, there were no adverse clinical sequelae. In follow-up evaluation transcatheter clamshell closure of patent foramen ovale has provided persistent relief from shuntrelated arterial desaturation and symptomatology in all living patients. © 1995 Wiley-Liss, Inc.