Expression map of entry receptors and infectivity factors for pan-coronaviruses in preimplantation and implantation stage human embryos

PURPOSE

To predict if developing human embryos are permissive to multiple coronaviruses.

METHOD

We analyzed publicly available single-cell RNA-seq datasets of human embryos for the known canonical and non-canonical receptors and spike protein cleavage enzymes for multiple coronaviruses like SARS-CoV, SARS-CoV-2, MERS-CoV, hCoV-229E, and hCoV-NL63. We also analyzed the expression of host genes involved in viral replication, host proteins involved in viral endosomal sorting complexes required for transport (ESCRT), genes of host proteins that physically interact with proteins of SARS-CoV-2, and the host genes essential for coronavirus infectivity.

RESULTS

Of the known receptors of SARS viruses, ACE2, BSG, GOLGA7, and ZDHHC5 were expressed in different proportions in the zygote, 4-cell, 8-cell, morula, and blastocysts including the trophectoderm. The MERS-CoV receptor, DPP4, and hCoV-229E receptor, ANPEP, were expressed mainly from the compact morula to the blastocyst stages. Transcripts of the MERS-CoV alternate receptor LGALS1 were detected in most cells at all stages of development. TMPRSS2 transcripts were detected in the epiblast, primitive endoderm, and trophectoderm, while transcripts of the endosomal proteases CTSL, CTSB, and FURIN were expressed in most cells at all stages of development. ACE2 and TMPRSS2 were co-expressed in a proportion of epiblast and trophectoderm cells. The embryonic cells expressed genes involved in ESCRT, viral replication, SARS-CoV-2 interactions, and coronavirus infectivity. The ACE2 and TMPRSS2 co-expressing cells were enriched in genes associated with lipid metabolism, lysosome, peroxisome, and oxidative phosphorylation pathways.

CONCLUSION

Preimplantation and implantation stage human embryos could be permissive to multiple hCoVs.

Prevalence of torus palatinus and torus mandibularis among Malay population

The aims of this study were to determine the prevalence, size, shape, and location of torus palatinus (TP) and torus mandibularis (TM), and to assess their sex-related and age-related differences in the Malay population. Sixty-five subjects were assessed for the presence of both tori at the School of Dental Sciences University Sains Malaysia. The prevalence of TP was 38–63% and that of TM was 1–10%. TP was frequently more common in females than males (90.9% versus 9.1%; P < 0.05) and was frequently found in medium sizes, spindle shaped, and was often located at the combined premolar to molar areas. The prevalence of TM was not significantly different in males and females (33.3% versus 66.7%; P = 0.523), occurred most commonly in bilateral multiple form, and was often located at the canine to premolar area.

Lymphatic vessel density is not associated with lymph node metastasis or survival in non-small cell lung carcinoma (NSCLC)

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Background: Angiogenesis is accepted as being essential for tumors to grow and metastasize to distant sites. Lymphatic metastasis is also an important means of tumor spread. Vascular endothelial growth factor C (VEGF-C) plays and important role in lymphangiogenesis and activates VEGFR (VEGF receptor)-3. Numerous studies suggest that tumor expression of VEGF-C is a significant prognostic factor in NSCLC. In non-small cell lung carcinoma (NSCLC), the relationship of lymphangiogenesis with lymph node metastasis and patient prognosis is unknown. Methods: A retrospective analysis of 78 patients who were diagnosed with NSCLC from 1987 to 2004 were analyzed for lymphatic vascular density (LVD). LVD was measured by use of D2–40 monoclonal antibody staining. Survival was assessed and Mantel-Cox and Wilcoxon signed rank tests were used for statistical analysis. Results: Intratumoral and peritumoral LVD was significantly higher than in the uninvolved adjacent lung, but showed no significant association with lymph node status at the time of tumor resection. Variables which appeared to affect survival in our study were the presence of lymph node metastasis (median survival 1,425 vs absence 467 days, p=0.002). The presence of VEGF staining inversely affected median survival (present 757 vs absent 1,944 days, p= 0.014). LVD ≤ 53 events per field 895 days vs >53 median survival 1,302 days, p+0.867. Survival appeared to not be affected by LVD. Conclusions: These data suggest that although lymphangiogenesis occurs in association with NSCLC, it may not be an important factor in lymph node metastasis or in survival. In fact, there is a suggestion that the number of lymphatics that a patient inherently has appears to be more important than lymphangiogenesis when it comes to the development of lymph node metastasis.

No significant financial relationships to disclose.

Indirect resin-bonded fibre-reinforced composite anterior bridge: A case report

In recent years fibre-reinforced resin composites (FRCs) have gained increasing acceptance in mainstream prosthodontics as viable alternatives to alloy-based restorations. A combination of good aesthetics and fracture toughness validates their use in a diverse range of clinical applications. In this case report an indirect resin-bonded fibre-reinforced composite anterior bridge incorporating a novel design is described. At 24-months recall the prosthesis was problem free and the patient was very happy with the treatment outcome. While definitive long-term data about their clinical performance is scarce, fibre-reinforced resin composite prostheses appear to have a worthwhile role in the conservative treatment of short edentulous spaces.

Evaluation and improvement of parasitological tests for Trypanosoma evansi infection

Research was undertaken to critically evaluate parasitological tests for the detection of Trypanosoma evansi in blood. The relative sensitivity of mouse inoculation (MI), the haematocrit centrifugation technique (HCT) and a modified miniature anion-exchange centrifugation technique (MAECT) were compared using blood and buffy coat. The effect that storage of blood prior to inoculation into mice has on the reliability of the MI test was also evaluated. The tests may be ranked in increasing order of sensitivity: HCT, MAECT with whole blood, MI with whole blood, MAECT with buffy coat and MI with buffy coat. The latter was able to detect 1.25 T. evansi per 4ml of blood. The reliability of the MI test was not reduced with storage of blood containing at least 25 T. evansi per ml for up to 21h prior to inoculation into mice. These results demonstrate that sensitivity of the MI and MAECT are increased approximately 10-fold through the use of buffy coat in place of whole blood. Although, the MI is marginally more sensitive MAECT is better suited to field use.

The susceptibility of two species of wallaby to infection with Trypanosoma evansi

OBJECTIVE

To determine the susceptibility of the agile wallaby (Macropus agilis) and the dusky pademelon (Thylogale brunil) to infection with Trypanosoma evansi.

METHOD

Two agile wallabies and three dusky pademelons were experimentally infected with between 5 x 10(4) and 10 x 10(4) T evansi from a cryopreserved stabilate isolated from an indonesian buffalo. Animals were observed twice daily for clinical signs and blood was collected every 3 days to determine parasitaemia. Necropsy was conducted on animals that died or were euthanised when in extremis and representative tissue sections examined.

RESULTS

All wallabies developed a high parasitaemia by 6 days after infection, which persisted until death or euthanasia in extremis, between days 8 and 61. Clinical signs included anorexia, weakness and ataxia. Anaemia occurred in one wallaby that survived for 61 days. Gross pathological changes varied between animals. They included pericarditis, serous atrophy of fat, splenomegaly, ulcerative gastritis and enteritis. Histological changes were characterised by a mononuclear cell infiltration of the connective tissue of most organs with little cellular destruction. Striking lesions were seen in the choroid, heart, stomach and small intestine.

CONCLUSION

Agile wallabies and pademelons are highly susceptible to infection with T evansi. Wallabies, therefore, have the potential to spread T evansi within New Guinea and Australia if infection is introduced. Mortality is likely to be high thereby acting as an indicator of recent introduction. Histological changes seen in wallabies infected with T evansi are diagnostic for infections occurring in Australia and Papua New Guinea.

The occurrence of Trypanosoma evansi in buffaloes in Indonesia, estimated using various diagnostic tests

The prevalence and incidence of Trypanosoma evansi infections in village buffaloes in Central Java were estimated using parasitological tests, two antigen-detection ELISAs (2G6 Ag-ELISA and Tr7 Ag-ELISA), an antibody-detection ELISA (IgG ELISA) and a card agglutination test (CATT). Of 2387 village buffaloes tested in five districts, 4 % (95 % confidence interval [CI]: 3 %, 5 %) were positive with the microhaematocrit test (MHCT), 58 % (95 % CI: 56 %, 60 %) were positive with the 2G6 Ag-ELISA and 70 % (95 % CI: 68 %, 72 %) were positive with the Tr7 Ag-ELISA. An increasing prevalence with age was found and the proportion of positive buffaloes was highest in the over 84 months-old age-group (68 %) with the 2G6 Ag-ELISA and in the 37-60 months-old age-group (78 %) with the Tr7 Ag-ELISA. Parasitaemic buffaloes were found in more than half of the villages visited. Corrected village-specific prevalence values obtained with the two Ag-ELISAs ranged from 0% to over 100%, and prevalence differed significantly (P < or = 0.0001) between villages in four of the five districts. Overall, 10% of buffaloes tested in markets were found to be parasitaemic and 39, 56 and 47 % were found positive with the 2G6 Ag-ELISA, IgG ELISA and CATT, respectively. Incidence rates varied according to the test used and ranged from 0.22 (95 % CI: 0.09, 0.44) to 0.44 (95 % CI: 0.24, 0.76), per animal-year at risk, in two villages. The results highlight the importance of using validated diagnostic tests to obtain accurate estimates of prevalence and incidence. These parameters are needed, for example in mathematical models, for the development and evaluation of different control strategies for T. evansi infections in buffaloes.

Evaluation of antigen detection and antibody detection tests for Trypanosoma evansi infections of buffaloes in Indonesia

Two Ag-ELISAs, an IgG-specific antibody detection ELISA (IgG ELISA) and a card agglutination test (CATT) for the detection of Trypanasoma evansi infections in buffaloes in Indonesia, were compared. Diagnostic sensitivity estimates were obtained by testing sera from 139 Indonesian buffaloes which had been found to be infected by parasitological tests. Diagnostic specificity was estimated by testing sera from 263 buffaloes living in Australia. Response-operating characteristic curves were constructed, and optimal ELISA cut-off values, which minimized the number of false-negative and false-positive results, were chosen. The IgG ELISA had the highest sensitivity (89%) and the CATT had the highest specificity (100%). There was a significant difference between the sensitivities (71 and 81%), but not between the specificities (75 and 78%), of the two Ag-ELISAs. The four tests were further compared by calculation of post-test probabilities of infection for positive and negative test results using a range of prevalence values, and likelihood ratios. The results suggested that the CATT was the best test to 'rule-in' infection (i.e. the highest probability of infection in test-positive animals) and the IgG ELISA was the best test to 'rule-out' infection (i.e. the lowest probability of infection in test-negative animals).

A possible role for rusa deer (Cervus timorensis russa) and wild pigs in spread of Trypanosoma evansi from Indonesia to Papua New Guinea

Movement of transmigrants and livestock from western Indonesia to southeastern areas of Irian Jaya near the border with Papua New Guinea may pose a risk of introducing Trypanosoma evansi into Papua New Guinea via feral Rusa deer (Cervus timorensis russa) and wild pigs which inhabit these areas in large numbers. Pilot experimental studies were conducted to observe infection in pigs and Rusa deer with a strain of T. evansi isolated in Indonesia. Parasitaemia and signs of clinical disease were monitored each second day for 120 days. Trypanosomes were observed in haematocrit tubes at the plasma-buffy coat interface of jugular blood of deer and pigs on 86% and 37% of sampling occasions respectively. Parasitaemia was at a high level in deer for 35% of the time but for only 11.5% of the time in pigs. Results indicate that both Rusa deer and pigs have a high tolerance for infection with T. evansi. The deer suffered mild anaemia evidenced by a 25% reduction in packed cell volume (PCV) 14 days after infection which coincided with the initial peak in parasitaemia. However, PCV had returned to pre infection values by the end of the experiment. The pigs showed no change in PCV. There were no visual indications of disease in either species and appetite was not noticeably affected. It was concluded that both Rusa deer and pigs were capable reservoir hosts for T. evansi but that Rusa deer, with their more persistent higher levels of parasitaemia, have more potential to spread T. evansi into Papua New Guinea from West Irian than pigs.