Costs and Impacts of Scaling up Voluntary Medical Male Circumcision in Tanzania

Background

Given the proven effectiveness of voluntary medical male circumcision (VMMC) in preventing the spread of HIV, Tanzania is scaling up VMMC as an HIV prevention strategy. This study will inform policymakers about the potential costs and benefits of scaling up VMMC services in Tanzania.

Methodology

The analysis first assessed the unit costs of delivering VMMC at the facility level in three regions—Iringa, Kagera, and Mbeya—via three currently used VMMC service delivery models (routine, campaign, and mobile/island outreach). Subsequently, using these unit cost data estimates, the study used the Decision Makers'' Program Planning Tool (DMPPT) to estimate the costs and impact of a scaled-up VMMC program.

Results

Increasing VMMC could substantially reduce HIV infection. Scaling up adult VMMC to reach 87.9% coverage by 2015 would avert nearly 23,000 new adult HIV infections through 2015 and an additional 167,500 from 2016 through 2025—at an additional cost of US$253.7 million through 2015 and US$302.3 million from 2016 through 2025. Average cost per HIV infection averted would be US$11,300 during 2010–2015 and US$3,200 during 2010–2025. Scaling up VMMC in Tanzania will yield significant net benefits (benefits of treatment costs averted minus the cost of performing circumcisions) in the long run—around US$4,200 in net benefits for each infection averted.

Conclusion

VMMC could have an immediate impact on HIV transmission, but the full impact on prevalence and deaths will only be apparent in the longer term because VMMC averts infections some years into the future among people who have been circumcised. Given the health and economic benefits of investing in VMMC, the scale-up of services should continue to be a central component of the national HIV prevention strategy in Tanzania.     

Strategies to target SARS-CoV-2 entry and infection using dual mechanisms of inhibition by acidification inhibitors

Many viruses utilize the host endo-lysosomal network for infection. Tracing the endocytic itinerary of SARS-CoV-2 can provide insights into viral trafficking and aid in designing new therapeutic strategies. Here, we demonstrate that the receptor binding domain (RBD) of SARS-CoV-2 spike protein is internalized via the pH-dependent CLIC/GEEC (CG) endocytic pathway in human gastric-adenocarcinoma (AGS) cells expressing undetectable levels of ACE2. Ectopic expression of ACE2 (AGS-ACE2) results in RBD traffic via both CG and clathrin-mediated endocytosis. Endosomal acidification inhibitors like BafilomycinA1 and NH₄Cl, which inhibit the CG pathway, reduce the uptake of RBD and impede Spike-pseudoviral infection in both AGS and AGS-ACE2 cells. The inhibition by BafilomycinA1 was found to be distinct from Chloroquine which neither affects RBD uptake nor alters endosomal pH, yet attenuates Spike-pseudovirus entry. By screening a subset of FDA-approved inhibitors for functionality similar to BafilomycinA1, we identified Niclosamide as a SARS-CoV-2 entry inhibitor. Further validation using a clinical isolate of SARS-CoV-2 in AGS-ACE2 and Vero cells confirmed its antiviral effect. We propose that Niclosamide, and other drugs which neutralize endosomal pH as well as inhibit the endocytic uptake, could provide broader applicability in subverting infection of viruses entering host cells via a pH-dependent endocytic pathway.     

A Ewing's Sarcoma Cell Line Showing Some, but Not All, of the Traits of a Cholinergic Neuron

Abstract: The Ewing's sarcoma cell line ICB 112 was examined in detail for a cholinergic phenotype. Choline acetyltransferase activity (12.3 ± 2.9 nmol/h/mg of protein) was associated with the presence of multiple mRNA species labeled with a human choline acetyltransferase riboprobe. Choline was taken up by the cells by a high-affinity, hemicholinium-3-sensitive transporter that was partially inhibited when lithium replaced sodium in the incubation medium; the choline taken up was quickly incorporated into both acetylcholine and phosphorylcholine. High-affinity binding sites for vesamicol, an inhibitor of vesicular acetylcholine transport, were also present. The mRNAs for synaptotagmin (p65) and the 15-kDa proteolipid were readily detected and were identical in size to those observed in cholinergic regions of the human brain. Cumulative acetylcholine efflux was increased by raising the extracellular potassium level or the addition of a calcium ionophore, but the time course of stimulated efflux was slow and persistent. These results show that this morphologically undifferentiated cell line is capable of acetylcholine synthesis and expresses markers for synaptic vesicles as well as proteins implicated in calcium-dependent release but lacks an organized release mechanism.     

VDAC is a conserved element of death pathways in plant and animal systems

Programmed cell death (PCD) is very much a part of plant life, although the underlying mechanisms are not so well understood as in animals. In animal cells, the voltage-dependent anion channel (VDAC), a major mitochondrial outer membrane transporter, plays an important role in apoptosis by participating in the release of intermembrane space proteins. To characterize plant PCD pathways by investigating the function of putative components in a mammalian apoptotic context, we have overexpressed a rice VDAC (osVDAC4) in the Jurkat T-cell line. Overexpression of osVDAC4 induces apoptosis, which can be blocked by Bcl-2 and the VDAC inhibitor DIDS. Modifying endogenous VDAC function by DIDS and hexokinase II (HxKII) in Jurkat cells inhibits mitochondria-mediated apoptotic pathways. Finally, we show that DIDS also abrogates heat-induced PCD in cucumber cotyledons. Our data suggest that VDAC is a conserved mitochondrial element of the death machinery in both plant and animal cells.     

Wikstrosin,a tricoumarin from Wikstroemia viridiflora

In the polar fraction of the extract from Wikstroemia viridiflora, daphnoretin and a new coumarin, wikstrosin, were identified. Wikstrosin has been characterised by chemical and spectral methods as a tricoumarin, a new class not reported hitherto in nature.     

Visualizing the Prostate Gland by MR Imaging in Young and Old Mice

Purpose

Prostate imaging requires optimization in young and old mouse models. We tested which MR sequences and field strengths best depict the prostate gland in young and old mice; and, whether prostate MR signal, size, and architecture change with age.

Technique

Magnetic resonance imaging (MRI) of the prostate of young (2 months) and old (18 months) male nude mice (n = 6) was performed at 4.7 and 7 T and SCID mice (n = 6) at 7 T field strengths, using T1, fat suppressed T1, DWI, T2, fat suppressed T2, as well as T2-based- and proton density-based Dixon “water only” sequences. Images were ranked for best overall sequence for prostate visualization, prostate delineation, and quality of fat suppression. Prostate volume and signal characteristics were compared and histology was performed.

Results

T2-based-Dixon “water only” images ranked best overall for prostate visualization and delineation as well as fat suppression (n = 6, P<0.001) at both 4.7 T and 7 T in nude and 7T in SCID mice. Evaluated in nude mice, T2-based Dixon “water only” had greater prostate CNR and lower fat SNR at 7 T than 4.7 T (P<0.001). Prostate volume was less in older than younger mice (n = 6, P<0.02 nude mice; n = 6, P<0.002 SCID mice). Prostate T2 FSE as well as proton density-based and T2-based-Dixon “water only” signal intensity was higher in younger than older mice (P<0.001 nude mice; P<0.01 SCID mice) both at 4.7 and 7 T. This corresponded to an increase in glandular hyperplasia in older mice by histology (P<0.01, n = 6).

Conclusion

T2-based Dixon “water only” images best depict the mouse prostate in young and old nude mice at 4.7 and 7 T. The mouse prostate decreases in size with age. The decrease in T2 and T2-based Dixon “water only” signal with age corresponds with glandular hyperplasia. Findings suggest age should be an important determinant when choosing models of prostate biology and disease.     

Noninvasive Assessment of Gene Transfer and Expression by In Vivo Functional and Morphologic Imaging in a Rabbit Tumor Model

Purpose

To evaluate the importance of morphology in quantifying expression after in vivo gene transfer and to compare gene expression after intra-arterial (IA) and intra-tumoral (IT) delivery of adenovirus expressing a SSTR2-based reporter gene in a large animal tumor model.

Materials and Methods

Tumor directed IA or IT delivery of adenovirus containing a human somatostatin receptor type 2A (Ad-CMV-HA-SSTR2A) gene chimera or control adenovirus (Ad-CMV-GFP) was performed in VX2 tumors growing in both rabbit thighs. Three days later, ¹¹¹In-octreotide was administered intravenously after CT imaging using a clinical scanner. ¹¹¹In-octreotide uptake in tumors was evaluated the following day using a clinical gamma-camera. Gene expression was normalized to tumor weight with and without necrosis. This procedure was repeated on nine additional rabbits to investigate longitudinal gene expression both 5 days and 2 weeks after adenovirus delivery. CT images were used to evaluate tumor morphology and excised tissue samples were analyzed to determine ¹¹¹In-octreotide biodistribution ex vivo.

Results

VX2 tumors infected with Ad-CMV-HA-SSTR2 had greater ¹¹¹In-octreotide uptake than with control virus (P<0.05). Intra-arterial and intra-tumoral routes resulted in similar levels of gene expression. Longitudinally, expression appeared to wane at 2 weeks versus 5 days after delivery. Areas of necrosis did not demonstrate significant uptake ex vivo. Morphology identified areas of necrosis on contrast enhanced CT and upon excluding necrosis, in vivo biodistribution analysis resulted in greater percent injected dose per gram (P<0.01) and corresponded better with ex vivo biodistribution(r = 0.72, P<0.01, Coefficient of the x-variable = .72) at 2 weeks than without excluding necrosis (P<0.01).

Conclusion

Tumor specificity and high transgene expression can be achieved in tumors via both tumor directed intra-arterial and intra-tumoral delivery in a large animal tumor model. Using clinical machines, morphologic imaging contributes to functional imaging for quantifying SSTR2-based reporter expression in vivo.     

Increased level of p27 subunit of proteasomes and its co-localization with tyrosinase in amelanotic melanoma cells indicate its direct role in the regulation of melanin biosynthesis

Proteasomes have been shown to be involved in the regulation of melanin biosynthesis in melanoma cells. Here we report on the correlation between proteasome subunits and Tyrosinase (Tyr) activity in different cell phenotypes, and thereby regulation of melanin biosynthesis in B16F10 mouse melanoma cells. Our results indicated that the quantity of proteasome subunit p27 is higher and that of the enzyme Tyr and its activity are lower in amelanotic melanoma cells, while the reverse is true in melanotic melanoma cells. Proteasome subunit p27, compared to another subunit p31, shows increased co-localization with Tyr and Tyrosinase related protein 1 (Trp1) in amelanotic cells to a greater extent than that in melanotic cells. On exposure to cycloheximide, increased Tyr degradation was seen in amelanotic cells, as indicated by increased co-localization of p27 and Tyr. Further, exposure of amelanotic melanoma cells with proteasome-specific inhibitor MG132 resulted in an increased Tyr activity, increased levels of Tyr and Trp1, leading to increased melanin synthesis. These results therefore suggest that proteasomes, particularly p27 subunit, are directly involved in the regulation of melanin biosynthesis in mouse melanoma cells.