Comparison of clinical diagnosis and standard laboratory and molecular methods for the diagnosis of genital ulcer disease in Lesotho: association with human immunodeficiency virus infection

A multiplex polymerase chain reaction (M-PCR) assay for Haemophilus ducreyi, Treponema pallidum, and herpes simplex virus (HSV) was compared with clinical and standard laboratory methods for the diagnosis of genital ulcer disease (GUD) in 105 patients; 36% were human immunodeficiency virus (HIV)-seropositive. Chancroid (80%), syphilis (8%), and genital herpes (8%) were the most frequent diagnoses. H. ducreyi and HSV were isolated from ulcers of 43% and 18% of patients, respectively; in 35%, all cultures were negative and the laboratory diagnosis indeterminate. M-PCR detected H. ducreyi, T. pallidum, and HSV in 56%, 23%, and 26% of patients, respectively; (no definitive diagnosis, 6%). The proportion of patients with more than one agent was 4% by culture and 17% by M-PCR (P = .002). Resolved sensitivities of M-PCR for H. ducreyi and HSV cultures were 95% and 93%, respectively. The sensitivities of H. ducreyi and HSV cultures were 75% and 60%, respectively. HSV, detected in 47% of specimens from HIV-infected versus 16% from HIV-uninfected patients (P < .001), may be emerging as a more frequent cause of GUD.     

Keeping calcium in its place: Ca(2+)-ATPase and phospholamban

Electron microscopy is gradually revealing more and more about the structure of the calcium pump from the sarcoplasmic reticulum, Ca(2+)-ATPase. The most recent result reveals the ATP-binding site, and two different avenues are being pursued towards achieving a higher resolution structure. Although no such structures are currently available for phospholamban, various spectroscopies and site-directed mutagenesis have been combined to produce a compelling structural model for its regulation of Ca(2+)-ATPase.     

Adrenomedullin, endothelin, neuropeptide Y, atrial, brain, and C-natriuretic prohormone peptides compared as early heart failure indicators

OBJECTIVES:The present investigation was designed to determine the best endogenous plasma marker of early congestive heart failure (CHF). METHODS: Forty volunteers with mild CHF (New York Heart Association Class I, n = 12), moderate (Class II, n = 8), or severe (Class III and Class IV, each = n of 5) and 10 age-matched healthy individuals had the simultaneous evaluation of their respective plasma samples by the following radioimmunoassays: atrial natriuretic peptide, ANP; three N-terminal ANP prohormone assays, i.e., proANPs 1-30, 31-67, and 79-98 with the numbers referring to their amino acid (a.a.) sequences in their 126 a.a. prohormone; brain (BNP) and C-natriuretic peptides; N-terminal BNP prohormone; adrenomedullin; neuropeptide Y and endothelin. RESULTS: ProANPs 31-67, 1-30 and 79-98 had 100% (P = 0.01), 83% (P = 0.09) and 50% (P = 0.74) sensitivity in differentiating Class I CHF subjects from healthy subjects. The ANP, BNP, NT-proBNP, CNP, adrenomedullin, neuropeptide Y, and endothelin assays could not differentiate mild CHF subjects from healthy individuals. Logistic regression analysis revealed that only proANP 31-67 significantly (P = 0.0001) discriminated between early CHF (5226 +/- 377 pg/ml) and healthy individuals (1595 +/- 157 pg/ml). The positive and negative predicative values of proANP 31-67 were excellent (100% for each). The peptides measured in these assays were found to be independent markers of CHF with respect to left ventricular ejection fraction. CONCLUSIONS: ProANPs 31-67 is the most sensitive marker in discriminating NYHA Class I CHF subjects from healthy individuals. The ANP, BNP, NT-proBNP, CNP, adrenomedullin, neuropeptide Y and endothelin radioimmunoassays cannot discern mild CHF. These peptides are independent of left ventricular ejection fraction.     

Coupling of skeletal muscle to a prosthesis for circulatory support

A durable bond between the end of skeletal muscles and prosthetic structures could, with appropriate linkage, allow circulatory support power by synchronous and/or sequential contraction of several in situ conditioned muscles. Potential advantages relative to a myoplasty wrap involve 1) less traumatic dissection, 2) efficient linear force development, 3) selectable contraction rate, 4) greater stroke work, 5) independent control of muscle pre-load and end diastolic pressure, and 6) independent control of duration of muscle tension and ejection time. However, no existing means of tissue-prosthetic bonding appears adequate. Practicality would demand that full tension bearing capacity by the bond take no longer than muscle conditioning. A prosthesis was developed to achieve those goals. As scaled for this study, it is made of 7,200-7,800 unspun, unplaited, 22 to 26 microns diameter polyester fibers swaged into four taper needles for weaving through distal muscle. The other end is formed into a polyurethane sheathed kernmantel cord for distal fixation. Devices were implanted in six 3 to 4 kg rabbits (unilateral posterior tibial tendon replacement, random side selection with contralateral dissection/closure controls), and their tensile strength was tested at 30 days. All healed well; leg movements were normal after 1 week. Limbs were frozen at -70 degrees C between death and testing. Control failure occurred at 243 +/- 94 N and experimental at 163 +/- 44 N (p = 0.065, t-test); highest estimated requirement was 17.2 N. Interface strength was adequate by 30 days. Continued investigations, addressing other questions, are warranted.     

Vasoactive intestinal polypeptide (VIP) innervation of rat spleen, thymus, and lymph nodes

In the thymus, VIP-positive (+) fibers were found in the capsular/septal system, cortex, and medulla. In the spleen, VIP+ nerves coursed along large arteries and central arterioles, and in the white pulp, venous/trabecular system, and red pulp. Splenic VIP innervation was more robust in Long-Evans hooded rats than in Fischer 344 rats. VIP+ nerves in mesenteric lymph nodes were found in the cortex, and along the cortical vasculature and medullary cords. No VIP innervation was observed in popliteal lymph nodes. Immunocytes also were VIP+, suggesting that both neural and cellular synthesis of VIP contributes to VIP concentration in lymphoid organs. Surgical sympathectomy did not alter splenic or thymic VIP content, respectively, and VIP innervation of these organs was not altered, suggesting an origin for VIP+ nerves other than the sympathetic nervous system.     

Detecting vascular problems in patients with diabetes treated with an intra-aortic balloon pump

Individuals with diabetes are at increased risk for both peripheral vascular disease and coronary artery disease. In patients with severe coronary artery disease, a cardiac assist device called an intra-aortic balloon pump (IABP) often is used to aid the failing heart and prevent further cardiac ischemia. Because this device is inserted via the femoral artery, patients are at risk of limb ischemia distal to the insertion site. Patients with diabetes are particularly prone to this complication. Detecting the early signs and symptoms of ischemia is crucial to preventing serious sequelae. Standard vascular examination techniques, in addition to being subjective and not easily reproducible, may be misleading in patients with diabetes. This article provides a review of the signs and symptoms of lower limb ischemia and noninvasive vascular tests that clinicians can use to evaluate lower extremity circulation. Also included are protocols for patient care during and after hospitalization, and two case studies of cardiac patients with diabetes who were treated with an IABP.     

Characterization of a site-directed mutant of cytochrome b5 designed to alter axial imidazole ligand plane orientation

Mutants of cytochrome b5 were designed to achieve reorientation of individual axial imidazole ligands. The orientation of the axial ligand planes is thought to modulate the reduction potential of bis(imidazole) axially ligated heme proteins. The A67V mutation achieved this goal through the substitution of a bulkier, hydrophobic ligand for a residue, in the sterically hindered hydrophobic heme binding pocket. Solution structures of mutant and wild-type proteins in the region of the mutation were calculated using restraints obtained from 1H and 15N 2D homonuclear and heteronuclear NMR spectra and 1H-15N 3D heteronuclear NMR spectra. More than 10 restraints per residue were used in the refinement of both structures. Average local rmsd for 20 refined structures was 0.30 A for the wild-type structure and 0.38 A for the A67V mutant. The transfer of amide proton resonance assignments from wild-type to the mutant protein was achieved through overlays of 15N-1H heteronuclear correlation spectra of the reduced proteins. Side chain assignments and sequential assignments were established using conventional assignment strategies. Calculation of the orientation of the components of the anisotropic paramagnetic susceptibility tensor, using methods similar to procedures applied to the wild-type protein, shows that the orientation of the in-plane components are identical in the wild-type and mutant proteins. However, the orientation of the z-component of the susceptibility tensor calculated for the mutant protein differs by 17 degrees for the A-form and by 11 degrees for the B-form from the orientation calculated for the wild-type protein. The rotation of the z-component of the susceptibility tensor (toward the delta meso proton) is in the same direction and is of the same magnitude as the rotation of the H63 imidazole ring induced by mutation.     

Strategy for development of a pre-erythrocytic Plasmodium falciparum DNA vaccine for human use

Data generated in the Plasmodium yoelii rodent model indicated that plasmid DNA vaccines encoding the P.yoelii circumsporozoite protein (PyCSP) or 17 kDa hepatocyte erythrocyte protein (PyHEP17) were potent inducers of protective CD8+ T cell responses directed against infected hepatocytes. Immunization with a mixture of these plasmids circumvented the genetic restriction of protective immunity and induced additive protection. A third DNA vaccine encoding the P. yoelii sporozoite surface protein 2 (PySSP2) also induced protection. The P. falciparum genes encoding the homologues of these three protective P. yoelii antigens as well as another P. falciparum gene encoding a protein that is expressed in infected hepatocytes have been chosen for the development of a human vaccine. The optimal plasmid constructs for human use will be selected on the basis of immunogenicity data generated in mice and nonhuman primates. We anticipate that optimization of multi-gene P. falciparum DNA vaccines designed to protect against malaria by inducing CD8+ T cells that target infected hepatocytes will require extensive clinical trials during the coming years.