Finite element analysis of bone-implant biomechanics: refinement through featuring various osseointegration conditions

A refinement technique is proposed for developing finite element models capable of simulating peri-implant bone conditions for bone types II, III, and IV at various degrees of osseointegration. The refined models feature a transition region between bone (cortical and cancellous) and implant and designate it partially to fully osseointegrated by assigning corresponding fractions of the bulk bone's elastic properties to this region. Bone is assumed to be transversely isotropic. The refined technique is implemented in a case study, in which osseointegrated (25-100%) peri-implant bone, type II, III, or IV with an implant attached, is loaded with a 100 MPa occlusal load. The biomechanics of this peri-implant bone was simulated and analysed. Results showed that the less dense bone must support higher stress and strain, especially at the cortical region. Higher degree of osseointegration induced higher stress but lower strain. Both the bone type and the osseointegration condition significantly affected the stress-strain relation. For minimum stress and strain, denser and more osseointegrated peri-implant bone is desirable. When bone failure criteria were set, based on the yield strength and strain of the bone, a higher degree of osseointegration was needed for the less dense peri-implant bone to be considered safe.     

Interleukin-28B Polymorphisms and Response of Chronic Hepatitis C Patients from Indonesia to Pegylated Interferon/Ribavirin Treatment

This study demonstrated that Indonesian patients with chronic hepatitis C (mostly ethnic Java people) mostly were infected with hepatitis C virus (HCV) genotype 1; however, they carried mainly the major genotypes of interleukin 28B (IL-28B) single nucleotide polymorphisms (SNPs) (rs12979860 CC, rs11881222 TT, rs8103142 AA, and rs8099917 TT), and they mostly achieved sustained virological responses to pegylated interferon/ribavirin treatment.     

Efficacy and safety of tixagevimab-cilgavimab as pre-exposure prophylaxis for COVID-19: A systematic review and meta-analysis

Some proportions of populations, such as immunocompromised patients and organ transplant recipients might have inadequate immune responses to the vaccine for coronavirus disease 2019 (COVID-19). For these groups of populations, administering monoclonal antibodies might offer some additional protection. This review sought to analyze the effectiveness and safety of tixagevimab-cilgavimab (Evusheld) as pre-exposure prophylaxis against COVID-19. We used specific keywords to comprehensively search for potential studies on PubMed, Scopus, Europe PMC, and ClinicalTrials.gov sources until 3 September 2022. We collected all published articles that analyzed tixagevimab-cilgavimab on the course of COVID-19. Review Manager 5.4 was utilized for statistical analysis. Six studies were included. Our pooled analysis revealed that tixagevimab-cilgavimab prophylaxis may decrease the rate of SARS-CoV-2 infection (OR: 0.24; 95% CI: 0.15–0.40, p < 0.00001, I² = 75%), lower COVID-19 hospitalization rate (OR: 0.13; 95% CI: 0.07–0.24, p < 0.00001, I² = 0%), decrease the severity risk (OR: 0.13; 95% CI: 0.07–0.24, p < 0.00001, I² = 0%), and lower COVID-19 deaths (OR: 0.17; 95% CI: 0.03–0.99, p = 0.05, I² = 72%). In the included studies, no major adverse events were reported. This study proposes that tixagevimab-cilgavimab was effective and safe for preventing COVID-19. Tixagevimab-cilgavimab may be offered to those who cannot be vaccinated or have inadequate immune response from the COVID-19 vaccine to give additional protection.     

Voluntary HIV testing, disclosure, and stigma among injection drug users in Bali, Indonesia.

Recently, large increases have been noted in injection drug use and HIV prevalence in Indonesia. Because voluntary HIV counseling and testing can play an important role in HIV prevention, it is important to understand factors related to its use. The objective of this study was to identify factors related to the use of voluntary HIV testing among drug users. In-depth interviews were conducted with a sample of 40 drug users in the Denpasar area of Bali, Indonesia. Drug users may be interested in testing if they have enough information about AIDS to know that they are at risk and that they need this information to protect themselves and others from infection. Barriers toward testing included the fear of a positive result, fear of reactions from family and community members and stigmatization. Other obstacles include a feeling of hopelessness, problems with testing, unavailability and side effects of AIDS drugs and other factors. Many persons would not disclose their status to community members and sexual partners. There were serious concerns about others being ashamed of them and the impact of HIV on relationships with spouses and sexual partners and on employment.     

Taeniasis/cysticercosis in Bali, Indonesia

Taenia solium and Taenia saginata are found in humans in Bali, Indonesia. During a field survey of 660 people in Bali from 2002-2009 of taeniasis/cysticercosis cases using mitochondrial DNA confirmation of the species, we detected 80 cases of T. saginata taeniasis, 2 dual T. saginata/T. solium infections with T. solium metacestodes in the brain and 12 neurocysticercosis (NCC) cases at Sanglah Hospital, Denpasar. Although the prevalence of NCC in Bali is low, sporadic cases are still present. There is no Taenia asiatica in Bali. We summarize here the field survey findings of taeniasis, including 1 dual infection with taeniasis and cysticercosis in 2007, and the reason why there are no T. asiatica cases and we describe 3 NCC cases admitted to Sanglah Hospital, Denpasar, Bali in 2004. Diagnosis was based on anamnesis, clinical examination, including CT Scan, histopathological, serological and mitochondrial DNA examinations. In order to prevent unexpected symptomatic NCC after treatment with praziquantel, we recommend introducing a rapid test to confirm taeniasis carriers and cysticercosis cases as a tool for real time diagnosis.     

Epidemiology of Staphylococcus aureus Harboring the mecA or Panton-Valentine Leukocidin Genes in Hospitals in Java and Bali,Indonesia

Data of Staphylococcus aureus carriage in Indonesian hospitals are scarce. Therefore, the epidemiology of S. aureus among surgery patients in three academic hospitals in Indonesia was studied. In total, 366 of 1,502 (24.4%) patients carried S. aureus. The methicillin-resistant S. aureus (MRSA) carriage rate was 4.3%, whereas 1.5% of the patients carried Panton-Valentine leukocidin (PVL)-positive methicillin-sensitive S. aureus (MSSA). Semarang and Malang city (odds ratio [OR] 9.4 and OR 9.0), being male (OR 2.4), hospitalization for more than 5 days (OR 11.708), and antibiotic therapy during hospitalization (OR 2.6) were independent determinants for MRSA carriage, whereas prior hospitalization (OR 2.5) was the only one risk factor for PVL-positive MSSA carriage. Typing of MRSA strains by Raman spectroscopy showed three large clusters assigned type 21, 24, and 38, all corresponding to ST239-MRSA-SCCmec type III. In conclusion, MRSA and PVL-positive MSSA are present among patients in surgical wards in Indonesian academic hospitals.     

Short report: polymorphisms in the chloroquine resistance transporter gene in Plasmodium falciparum isolates from Lombok, Indonesia

The polymorphisms in the Plasmodium falciparum multidrug resistance 1 (pfmdr1) and P. falciparum chloroquine resistance transporter (pfcrt) genes, which are associated with chloroquine resistance, were examined in 48 P. falciparum isolates from uncomplicated malaria patients from the West Lombok District in Indonesia. The point mutation N86Y in pfmdr1 was present in 35.4% of the isolates and mutation K76T in pfcrt was found in all but one of the samples studied. Identified pfcrt haplotypes were mainly identical to the Papua New Guinea type S(agt)VMNT (42 of 48, 87.5%), and a few isolates had the Southeast Asia type CVIET (5 of 48, 10.4%). Moreover, one P. falciparum isolate harbored the K76N mutation, giving rise to the haplotype CVMNN, which was not previously reported in field isolates. Our findings suggest that chloroquine resistance in this area might have the same origin as in Papua New Guinea.     

Segmentation of the C57BL/6J mouse cerebellum in magnetic resonance images

The C57BL mouse is the centerpiece of efforts to use gene-targeting technology to understand cerebellar pathology, thus creating a need for a detailed magnetic resonance imaging (MRI) atlas of the cerebellum of this strain. In this study we present a methodology for systematic delineation of the vermal and hemispheric lobules of the C57BL/6J mouse cerebellum in magnetic resonance images. We have successfully delineated 38 cerebellar and cerebellar-related structures. The higher signal-to-noise ratio achieved by group averaging facilitated the identification of anatomical structures. In addition, we have calculated average region volumes and created probabilistic maps for each structure. The segmentation method and the probabilistic maps we have created will provide a foundation for future studies of cerebellar disorders using transgenic mouse models.