SARS-CoV-2 reinfection in patients negative for immunoglobulin G following recovery from COVID-19.

While many patients infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) eventually produce neutralising antibodies, the degree of susceptibility of previously infected individuals to reinfection by SARS-CoV-2 is currently unknown. To better understand the impact of the immunoglobulin (IgG) level on reinfection in recovered coronavirus disease 2019 (COVID-19) patients, anti-nucleocapsid IgG levels against SARS-CoV-2 were measured in 829 patients with a previously confirmed infection just after their recovery. Notably, 87 of these patients had no detectable IgG concentration. While there was just one case of asymptomatic reinfection 4.5 months after the initial recovery amongst patients with detectable anti-nucleocapsid IgG levels, 25 of the 87 patients negative for anti-nucleocapsid IgG were reinfected within one to three months after their first infection. Therefore, patients who recover from COVID-19 with no detectable anti-nucleocapsid IgG concentration appear to remain more susceptible to reinfection by SARS-CoV-2, with no apparent immunity. Also, although our results suggest the chance is lower, the possibility for recovered patients with positive anti-nucleocapsid IgG findings to be reinfected similarly exists.

Feline ocular toxoplasmosis: seroprevalence, diagnosis and treatment outcome of 60 clinical cases.

Toxoplasmosis is one of the most important protozoa zoonotic diseases worldwide. The present study describes the clinical, seroprevalence findings with ocular toxoplasmosis and the outcome of medicinal treatment of these cats. This study was carried out on 105 cats with various ocular signs, no historical evidence of ocular trauma or drug/vaccine exposure for at least 3 months prior to admission, and without clinical or laboratory evidence of other systemic diseases. Complete case history, physical and ophthalmic examinations were carried out. The seroprevalence of Toxoplasma gondii antibodies was determined using the Toxoplasma Ab Rapid Test and Enzyme Linked Immunosorbent Assay. Out of 105 examined cats with ocular lesions, 60 cats representing 57.14% were seropositive to T. gondii. Out of these 60 cats, 15 cats (25%) had bilateral ocular abnormalities, 25 cats (41.67%) had right-sided ocular disease, and 20 cats (33.33%) had left-sided ocular disease. There were 38 cats (63.33%) with anterior uveitis, 12 cats (20%) with posterior segment involvement, 5 cats (8.33%) with anterior uveitis and anterior chamber abnormalities, 3 cats (5%) with corneal abnormalities and 2 cats (3.34%) with anterior uveitis with concurrent corneal involvement. There was a significant difference in the index values of IgM and IgG between seropositive and seronegative cats with T. gondii antibodies (p⟨0.05). There was no significant difference between the different ages, genders and breeds of cats with seroprevalence of T. gondii antibodies as well as between the age and total number of cats with seropositive and seronegative T. gondii. Out of 60 treated cats, 28 cats (46.7%), 25 cats (41.7%) and 7 cats (11.6%) showed complete, partial and poor response to treatment, respectively. In conclusion, cats showing ocular signs without obvious etiology should be examined serologically for toxoplasmosis and the seropositive cats should be treated with both specific topical and systemic treatments.

An assessment of anthropogenic and climatic stressors on estuaries using a spatio-temporal GIS-modelling approach for sustainability: Towamba estuary, southeastern Australia.

Monitoring estuarine ecological-geomorphological dynamics has become a crucial aspect of studying the impacts of climate change and worldwide infrastructure development in coastal zones. Together, these factors have changed the natural eco-geomorphic processes that affect estuarine regimes and comprehensive modelling of coastal resources can assist managers to make appropriate decisions about their sustainable use. This study has utilised Towamba estuary (southeastern NSW, Australia), to demonstrate the value and priority of modelling estuarine dynamism as a measure of the rates and consequences of eco-geomorphic changes. This research employs several geoinformatic modelling approaches over time to investigate and assess how climate change and human activities have altered this estuarine eco-geomorphic setting. Multitemporal trend/change analysis of sediment delivery, shoreline positions and land cover, determined from fieldwork and GIS analysis of remote sensing datasets, shows significant spatio-temporal changes to the elevation and areal extent of sedimentary facies in the Towamba estuary over the past 65 years. Geomorphic growth (~ 2600 m2 annually) has stabilised the estuarine habitats, particularly within native vegetation, salt marsh and mangrove areas. Geomorphic changes have occurred because of a combination of sediment runoff from the mostly unmodified terrestrial catchment, nearshore processes (ocean dynamics) and human activities. The construction of GIS models, verified with water and sediment samples, can characterise physical processes and quantify changes within the estuarine ecosystem. Such robust models will allow resource managers to evaluate the potential effects of changes to the current coastal ecosystems.

Corrective role of Eugenia jambolana on testicular impairment in streptozotocin-induced diabetic male albino rat: an approach through genomic and proteomic study.

The present study was conducted to explore the effect of ethyl acetate fraction of hydro-methanolic (40 : 60) extract of seed of Eugenia jambolana on testicular impairment in diabetic rats. In this respect, biomarkers of oxidative stress, genomics and proteomics in testicular tissue were assessed. Side by side, glycated haemoglobin, serum testosterone, activities of glutamate oxaloacetate transaminase and glutamate pyruvate transaminase in serum, epididymal sperm count including reproductive organosomatic indices were evaluated. Results indicate that a significant recovery (P < 0.05) in the levels of these parameters in fraction-treated diabetic group in comparison with diabetic control. A significant recovery was noted (P < 0.05) in the expression of Bax and Bcl-2 gene towards the control after the treatment of said fraction. Histological study also focused a significant recovery (P < 0.05) in the number of different generation of germ cells at stage VII of spermatogenesis in fraction-treated diabetic group. The said fraction treatment to diabetic rat can recover the activities of serum glutamate oxaloacetate transaminase and glutamate pyruvate transaminase significantly towards the control (P < 0.05). Finally, it may be concluded that ethyl acetate fraction of seed of E. jambolana has a promiseable remedial effect on diabetes-induced testicular dysfunctions in male rat without inducing any metabolic toxicity.

Antimalarial prescribing and dispensing practices in health centres of Khartoum state, 2003-04.

This indicator-based study assessed the antimalarial drug prescribing and dispensing practices of health care providers in health centres of Khartoum state, and compared these with national guidelines for malaria treatment. A total of 720 patients and their prescriptions in 24 health centres were included. Prescribers adhered to national treatment guidelines for only 278 (38.6%) of patients. Although all were treated for malaria, only 77.6% patients had fever or history of fever and only 64.6% had fever and positive blood films. More than 90% of prescriptions prescribed antimalarial drugs by generic names but dosage forms were correctly written in only 23.5%. There was a high rate of prescribing antimalarial injections. Only half the patients had adequate knowledge of their treatment.

Collateral effects of antiarrhythmics in pediatric age.

Although there are numerous reports of antiarrhythmic use in children, controlled, comparison trials of antiarrhythmic agents in children are virtually nonexistent and most data are obtained from case series of children treated. Effective and safe pharmacological therapy requires that the physicians attempt to identify a drug with the most appropriate profile to attack the most vulnerable parameter of the mechanisms of the cardiac arrhythmia with the least pro arrhythmic/collateral effects. Digoxin in patients with Wolf-Parkinson -White syndrome, verapamil in infants and intravenous quinidine should be avoided as there is clear evidence that they can cause serious side effects. Collateral effects of other antiarrhythmic drugs are discussed in details in this review. Well-designed, controlled trials are needed to further evaluate the comparative efficacy of antiarrhythmics in children, as well as to evaluate dosing and toxicity in various age groups.

Echocardiographic differentiation of atrioventricular septal defects from inlet ventricular septal defects and mitral valve clefts.

Left ventricular inlet/outlet ratio and percent left atrioventricular valve (AVV) guarded by the posterior leaflet are valuable for characterizing atrioventricular septal defect (AVSD). We performed these measurements echocardiographically in normal patients (n = 101), patients who had AVSD (n = 37), those who had isolated perimembranous inlet ventricular septal defect (VSD; n = 12), and those who had "isolated" mitral valve clefts (n = 5). Surgical findings of 38 patients were reviewed. The normal inlet/outlet ratio was 1.03 +/- 0.07. For patients who had AVSD, the ratio was 0.82 +/- 0.06 (95% confidence interval [CI] 0.180 to 0.237, p = 0.001). For patients who had an isolated inlet VSD, this ratio was lower than that in normal patients (0.93 +/- 0.08, 95% CI 034 to 0.116, p = 0.001) but higher than that in patients who had AVSD (95% CI -0.175 to 0.091, p = 0.001). The percent left AVV guarded by the posterior leaflet was 56 +/- 1.4 in normal patients. For patients who had AVSD, it was significantly lower (43 +/- 1.1). For patients who had an isolated VSD and those who had an isolated mitral cleft, it was normal (57 +/- 1.9 and 55 +/- 2.2, respectively). The 2 measurements are valuable in differentiating AVSD from inlet VSD and isolated mitral cleft, but percent left AVV guarded by the posterior leaflet is more specific.

A recombinant Leishmania chagasi antigen that stimulates cellular immune responses in infected mice.

Cellular immune mechanisms resulting in gamma interferon production are critical for protection against visceral leishmaniasis. Antigens stimulating T-cell responses are likely present in the intracellular amastigote form of the parasite, since this is the form found in a mammalian host. To identify T-cell antigens of Leishmania chagasi, the parasite causing South American visceral leishmaniasis, we used a double antibody-T-cell technique to screen an amastigote cDNA library. One cDNA selected (Lcr1) encodes an antigen that stimulated proliferation of splenic T lymphocytes from infected mice that were either resistant (C3H.HeJ) or susceptible (BALB/c) to L. chagasi infection. The Lcr1 cDNA contains four highly divergent 201-bp repeats homologous to the 204-bp repeat of a Trypanosoma cruzi flagellar antigen gene. Results are consistent with a single copy of the Lcr1 gene producing an mRNA of > 10 kb and a protein of > 200 kDa. Recombinant Lcr1, cloned adjacent to polyhistidine and purified on a nickel affinity column, stimulated gamma interferon but not interleukin-4 (IL-4), IL-5, or IL-10 secretion by T-cell-enriched splenocytes from either susceptible or resistant mice during L. chagasi infection. Immunization with Lcr1 partially protected BALB/c mice against challenge with L. chagasi, indicating the utility of the double screening approach in selecting relevant T-cell antigens.

[Morphometric study of the effect of 5-hydroxytryptophan on the activity of various hypothalamic centers in rats depending on the state of their sexual system]. / Morfometricheskoe izuchenie vliianiia 5-oksitriptofana na aktivost' nekotorykh gipotalamicheskikh tsentrov u krys v zavisimosti ot sostoianiia ikh polovoi sistemy.

The effect of 5-oxytryptophan (serotonin metabolic precursor), injected intraperitoneally to female rats (intact and with deafferented mediobasal hypothalamus) on the activity of a number of hypothalamic centres was studied. The activity of cells, both outside and inside the isolated area, proved to alter under the effect of 5-oxytryptophan. The direction of these effects depends on the initial state of the hypothalamic centres and on the hormone in whose presence serotonin acts.

Chemical aspects of radiosensitization. Reaction of sensitizers with radicals produced in the radiolysis of aqueous solutions of nucleic acid components.

The effects of oxidants (sensitizers) in the radiolysis of aqueous solutions of pyrimidine and purine bases have been investigated. Their influence on the nature of the permanent radiolysis products and on the kinetics of disappearance of transient intermediates is reported. Particular attention has been paid to the chemical fates of carbocationic intermediates which can be produced from radical-sensitizer interaction.