Comparative performances of enzyme-linked immunosorbent, western blot, and polymerase chain reaction assays for human T-lymphotropic virus type II infection that is endemic among Indians of the Gran Chaco region of South America.

BACKGROUND: Human T-cell lymphoma/leukemia viruses types I and II (HTLV-I and HTLV-II) are related exogenous human retroviruses. The former is definitely pathogenic while disease association with the latter is unclear. There are two subtypes of HTLV-II, A and B. Currently, enzyme-linked immunosorbent assays (ELISAs) based on HTLV-I antigens are used to screen for the presence of HTLV-I and -II antibodies. Confirmation and subtyping are accomplished by Western blot (WB) or ELISAs based on HTLV-I whole viral antigens and/or HTLV-I and HTLV-IIA peptides. The sensitivity and specificity of these serologic assays were compared to those of HTLV-I and-II-specific polymerase chain reaction (PCR) assays in tests on samples from Indians from South America in whom the HTLV-IIB subtype is endemic. STUDY DESIGN AND METHODS: Sera from 246 Gran Chaco Indians were evaluated for HTLV antibodies with the use of four ELISAs (Retrotek HTLV-I; Cambridge Biotech rgp21 enhanced HTLV-I/II; Vironostika HTLV-I/II; and Select HTLV-I/II), and a WB assay. Peripheral blood leukocyte DNA from each Indian was analyzed for HTLV-I or HTLV-II pol DNA via PCR. Fifteen of the PCR-positive samples were further subtyped via cloning and sequencing and/or oligomer restriction. RESULTS: Ninety-seven samples (39%) were positive for HTLV-II by serologic and/or PCR assays. All 15 positive DNA samples that were further analyzed were of the HTLV-IIB subtype and were clustered as a highly conserved phylogenetic group. Comparative analyses indicate that the sensitivity and specificity of the various assays were: PCR, 97 and 100 percent; Retrotek, 70 and 91 percent; Cambridge Biotech, 74 and 96 percent; Vironostika, 73 and 99 percent; Select 72 and 98 percent; and WB, 70 and 100 percent. CONCLUSION: The sensitivities of the tested HTLV serologic assays were comparable. However, the specificity of the Retrotek ELISA was significantly lower than that of the others. When positive, the subtyping assays were very specific. However, PCR assays would seem preferable or to be a necessary adjunct for the sensitive detection of HTLV-IIB infection.

Neurovascular injuries to the shoulder complex.

The shoulder complex is particularly vulnerable to neurovascular injuries due to its intimate anatomical relationship with the brachial plexus and axillary vessels. Therapists, trainers, and physicians who cover athletic events witness the violence of injury to the neck and shoulder. Fortunately, permanent neurovascular deficits are rare, and many are subtle. However, tragically, some can be career-ending and even life-threatening. Neurovascular injuries may occur in association with musculoskeletal injury or as an isolated finding. Symptoms may present on an acute basis or in a chronic fashion. On the playing field or in the emergency room, focus is often placed on the obvious musculoskeletal injury, ie., dislocation or fracture. Medical personnel must always have a high index of suspicion of neurovascular injuries to the shoulder complex to avoid misdiagnosis. They must consider that failure to progress in rehabilitation for musculoskeletal injuries may be secondary to a previously unrecognized neurovascular lesion. The purpose of this review is to provide a basic reference for diagnosis and treatment of neurovascular injuries to the shoulder complex for therapists, trainers, and physicians. Also, we hope to raise the index of suspicion for neurovascular injuries during evaluation of patients with common shoulder injuries. The review is organized by location and association with specific musculoskeletal injuries.

Transtrochanteric anterior rotational osteotomy for avascular necrosis of the femoral head. Long-term results.

We reviewed 18 hips in 17 patients at a mean of five years after performing Sugioka's transtrochanteric anterior rotational osteotomy for avascular necrosis. The results were satisfactory in only three hips (17%). Twelve hips had been revised by hip replacement, revision was pending in one and two others were unsatisfactory. Hip replacement was not compromised by the previous Sugioka osteotomy. Fifteen hips (83%) had shown further collapse of the femoral head, and we conclude from this and from isotope scans that the osteotomy may have impaired the residual blood supply of the femoral head. It seems that ethnic origin may be a factor in the outcome of this procedure; we have abandoned its use.

Antagonist drugs and bone vascular smooth muscle.

An ex vivo canine tibia model was used to quantitate the specific adrenergic subtype contribution in bone vasculature. Tibiae were obtained from mongrel dogs, the nutrient artery was catheterized, and the bone was placed in an ex vivo perfusion apparatus at constant flow. Perfusion was accomplished using oxygenated Krebs-Ringer solution. A norepinephrine dose-response curve was obtained by using incremental single bolus doses. Each bone was perfused with a vasoactive drug at a standard physiologic dosage. After 30 min of perfusion, a second norepinephrine dose-response curve was generated. The degree of attenuation of the norepinephrine dose-response curve, as determined by the total area under the curve, was interpreted as the relaxation effect of the drug on the smooth muscle of the vascular bed. Prazosin (alpha 1-receptor antagonist), rauwolszin (alpha 2-receptor antagonist), propranolol (beta-receptor antagonist), and diltiazem (calcium-entry inhibitor) were evaluated. Our data suggest that alpha 1 and alpha 2 adrenergic receptor antagonism results in a quantitatively similar attenuation of norepinephrine-induced vascular smooth muscle contraction. Calcium-entry antagonism produced less, but significant, attenuation of smooth muscle contractility. Beta-adrenergic receptor blockade yielded only a slight, although consistent, reduction in reactivity. Simple perfusion with Krebs-Ringer solution had no effect.

Virucidal efficacy of various lens cleaning and disinfecting solutions on HIV-I contaminated contact lenses.

The virucidal efficacy of various commercially available contact lens care cleaning regimens on human immunodeficiency virus (HIV-1) contaminated contact lenses using either cursory or meticulous cleaning with a rubber policeman was evaluated. Levels of infectious HIV-1 remaining on individual contact lenses were determined by cultivating the lenses with target HUT-78 cells and subsequently analyzing the cultures for the production of HIV-1 p24 by antigen capture and for HIV-1 gag gene DNA content by the polymerase chain reaction. The data indicate that most of the lens care regimens tested, when coupled with meticulous rubbing, were capable of safely decontaminating the contact lenses, that is, they reduce the amount of infectious HIV-1 on the lenses by greater than a 10 log concentration (10(-10], relative to standard controls. Most tested lens care regimens, if properly followed, would virtually eliminate any chance of the lens serving as a vector for HIV.