The ultrastructural organization of the mature spermatozoon of Luidia clathrata (Say) (Echinodermata: Asteroidea)

The sperm of Luidia clathrata are morphologically typical of asteroid sperm. The head is spherical and contains the nucleus and acrosomal complex. The nucleus has an anterior indentation in which rests the acrosomal complex. There is no evidence of a centriolar fossa along the posterior border of the nucleus. The acrosome is a cup-shaped structure containing a less electron dense central region. The periacrosomal material is homogeneous in nature, and the subacrosomal specialization of the periacrosomal materials appear as bands of varying electron density. The middle piece is an annular band of mitochondria which surrounds the proximal and distal centrioles. The centrioles exhibit the typical nine triplet arrangement. Both the centrioles and the axoneme project to one side of the middle piece region. Associated with the distal centriole is an elaborate pericentriolar process.     

EFFECT OF THE ADMINISTRATION OF L-5-HYDROXYTRYPTOPHAN AND A MONOAMINE OXIDASE INHIBITOR ON GLUCOSE METABOLISM IN RAT BRAIN

The effects of the presence of large amounts of 5-HT and of its precursor 5-HTP in brain on cerebral utilization of glucose were studied. [U-¹⁴C]Glucose was injected to fed rats that had previously been treated with L-5-HTP, L-5-HTP and an inhibitor—N-[β-(2-chlorophenoxy)-ethyl]-cyclopropylamine hydrochloride (Lilly-51641)-of MAO, or Lilly-51641 alone. Such treatment increased the concentrations of 5-HTP and 5-HT in the brain. After treatment with 5-HTP and Lilly-51641, and to a lesser extent with Lilly-51641 alone, the concentration of glucose in plasma was increased. However, the uptake of glucose by the brain did not appear to be proportionately increased, and this suggested an impairment in this mechanism. After the administration of Lilly-51641 alone and more especially of Lilly-51641 plus 5-HTP, the concentration of glucose in the brain was increased. This increase was thought to be due to an impairment of glucose utilization, because the flux of ¹⁴C from glucose to amino acids in the brain was reduced. The concentrations of most major amino acids in the brain were not greatly affected by these treatments. GABA and alanine concentrations in the brain were modestly increased after treatment with 5-HTP alone or in combination with Lilly-51641. The present results suggest that the metabolism of glucose to amino acids in the brain is altered when the concentration of 5-HTP, or more especially that of 5-HT, in the brain is increased.     

Predicted Delays in the Activation of the Contractile System

The capacitance C'(e), presumed to be located across the walls of the transverse tubules of twitch fibers, was identified in earlier impedance measurements by virtue of having a resistance in series with it. When the voltage V(m) across the surface membrane is made to vary, the voltage V(c) across C'(e) will be delayed with respect to V(m), the extent of the delay depending on the location of the series resistance. Model 1 assumes that the resistivity of the lumen of the tubules is negligible; model 2 assumes that the series resistance arises entirely in the tubular lumen; model 3 assumes that the resistivity of the tubular lumen is small, but not negligible and that the bulk of the resistance arises in a structure directly in series with C'(e) and having a similar geometric distribution. If V(m) varies sinusoidally, the relative value of V(c(max)) will fall with increasingly higher powers of the frequency at the center of the fiber if model 2 is applicable, whereas models 1 and 3 predict that V(c(max)) will fall at high frequency only in proportion to the frequency everywhere in the cross-section of the fiber. Equations have been derived for the voltage change V(c) in response to a step change of V(m) and during an action potential. On the assumption that contraction is initiated when V(c) reaches mechanical threshold, the delay between the activation of myofibrils on the axis of the fiber and at the surface would amount to 2.6 msec in model 2 and 0.25 msec in model 3 for frog fibers of about 100 mum diameter during a twitch.     

Implementation of Tuberculosis Intensive Case Finding,Isoniazid Preventive Therapy,and Infection Control ("Three I's") and HIV-Tuberculosis Service Integration in Lower Income Countries

SettingWorld Health Organization advocates for integration of HIV-tuberculosis (TB) services and recommends intensive case finding (ICF), isoniazid preventive therapy (IPT), and infection control (“Three I’s”) for TB prevention and control among persons living with HIV.ObjectiveTo assess the implementation of the “Three I’s” of TB-control at HIV treatment sites in lower income countries.DesignSurvey conducted between March-July, 2012 at 47 sites in 26 countries: 6 (13%) Asia Pacific, 7 (15%), Caribbean, Central and South America, 5 (10%) Central Africa, 8 (17%) East Africa, 14 (30%) Southern Africa, and 7 (15%) West Africa.ResultsICF using symptom-based screening was performed at 38% of sites; 45% of sites used symptom-screening plus additional diagnostics. IPT at enrollment or ART initiation was implemented in only 17% of sites, with 9% of sites providing IPT to tuberculin-skin-test positive patients. Infection control measures varied: 62% of sites separated smear-positive patients, and healthcare workers used masks at 57% of sites. Only 12 (26%) sites integrated HIV-TB services. Integration was not associated with implementation of TB prevention measures except for IPT provision at enrollment (42% integrated vs. 9% non-integrated; p = 0.03).ConclusionsImplementation of TB screening, IPT provision, and infection control measures was low and variable across regional HIV treatment sites, regardless of integration status.     

Global Health Diplomacy,Monitoring & Evaluation,and the Importance of Quality Assurance & Control: Findings from NIMH Project Accept (HPTN 043): A Phase III Randomized Controlled Trial of Community Mobilization,Mobile Testing,Same-Day Results,and Post-Test Support for HIV in Sub-Saharan Africa and Thailand

Background

Provision and scale-up of high quality, evidence-based services is essential for successful international HIV prevention interventions in order to generate and maintain intervention uptake, study integrity and participant trust, from both health service delivery and diplomatic perspectives.

Methods

We developed quality assurance (QAC) procedures to evaluate staff fidelity to a cluster-randomized trial of the NIMH Project Accept (HPTN 043) assessing the effectiveness of a community-based voluntary counseling and testing strategy. The intervention was comprised of three components—Mobile Voluntary Counseling and Testing (MVCT), Community Mobilization (CM) and Post-Test Support Services (PTSS). QAC procedures were based on standardized criteria, and were designed to assess both provider skills and adherence to the intervention protocol. Supervisors observed a random sample of 5% to 10% of sessions each month and evaluated staff against multiple criteria on scales of 1–5. A score of 5 indicated 100% adherence, 4 indicated 95% adherence, and 3 indicated 90% adherence. Scores below 3 were considered unsatisfactory, and protocol deviations were discussed with the respective staff.

Results

During the first year of the intervention, the mean scores of MVCT and CM staff across the 5 study sites were 4 (95% adherence) or greater and continued to improve over time. Mean QAC scores for the PTSS component were lower and displayed greater fluctuations. Challenges to PTSS staff were identified as coping with the wide range of activities in the PTSS component and the novelty of the PTSS process. QAC fluctuations for PTSS were also associated with new staff hires or changes in staff responsibilities. Through constant staff monitoring and support, by Year 2, QAC scores for PTSS activities had reached those of MVCT and CM.

Conclusions

The implementation of a large-sale, evidence based HIV intervention requires extensive QAC to ensure implementation effectiveness. Ongoing appraisal of study staff across sites ensures consistent and high quality delivery of all intervention components, in keeping with the goals of the study protocol, while also providing a forum for corrective feedback, additional supervision and retraining of staff. QAC ensures staff fidelity to study procedures and is critical to the successful delivery of multi-site HIV prevention interventions, as well as the delivery of services scaled up in programmatic situations.     

The mandibular organ of the female spider crab,Libinia emarginata,in immature,mature, and ovigerous crabs

The cells of mandibular organs of female Libinia emarginata exhibit changes in substructure during molting and vitellogenesis. The cytoplasm is that of a steroid-hormone producing cell. The cells do not appear to produce ecdysones.     

Spermiogenesis in a hermit-crab, Coenobita clypeatus. II. Sertoli cells

The testes of the land hermit crab, Coenobita clypeatus, contains germinal cells and non-germinative cells. The latter function in the manner of the vertebrate Sertoli cells in apparently providing nourishment, support and possibly hormones during spermiogenesis. Each Sertoli cell surrounds several germinal cells. The mitochondria, rough and smooth endoplasmic reticulum and Golgi apparatus show changes in structure when in contact with germinal cells in different stages of spermiogenesis. These changes are suggestive of active synthesis and metabolism of cellular product(s).