Reinfection risk of novel coronavirus (COVID-19): A systematic ‎review of current evidence

BACKGROUNDThere is recently a concern regarding the reinfection and reactivation of previously reCoVered coronavirus disease 2019 (CoVID-19) patients.AIMTo summarize the recent findings and reports of CoVID-19 reinfection in patients previously reCoVered from the disease.METHODSThis study was a systematic review of current evidence conducted in August 2020. The authors studied the probable reinfection risk of novel coronavirus (CoVID-19). We performed a systematic search using the keywords in online databases. The investigation adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to ensure the reliability and validity of this study and results.RESULTSWe reviewed 31 studies. Eight studies described reCoVered patients with reinfection. Only one study reported reinfected patients who died. In 26 studies, there was no information about the status of the patients. Several studies indicated that reinfection is not probable and that post-infection immunity is at least temporary and short.CONCLUSIONBased on our review, we concluded that a positive polymerase chain reaction retest could be due to several reasons and should not always be considered as reinfection or reactivation of the disease. Most relevant studies in positive retest patients have shown relative and probably temporary immunity after the reCoVery of the disease.     

Latency characteristics in specific pathogen-free chickens 21 and 35 days after intra-tracheal inoculation with vaccine or field strains of infectious laryngotracheitis virus

ABSTRACT

Latency is an important feature of infectious laryngotracheitis virus (ILTV) yet is poorly understood. This study aimed to compare latency characteristics of vaccine (SA2) and field (CL9) strains of ILTV, establish an in vitro reactivation system and examine ILTV infection in peripheral blood mononuclear cells (PBMC) in specific pathogen-free chickens. Birds were inoculated with SA2 or CL9 ILTV and then bled and culled at 21 or 35 days post-inoculation (dpi). Swabs (conjunctiva, palatine cleft, trachea) and trigeminal ganglia (TG) were examined for ILTV DNA using PCR. Half of the TG, trachea and PBMC were co-cultivated with cell monolayers to assess in vitro reactivation of ILTV infection. ILTV DNA was detected in the trachea of approximately 50% of ILTV‐inoculated birds at both timepoints. At 21?dpi, ILTV was detected in the TG only in 29% and 17% of CL9- and SA2-infected birds, respectively. At 35?dpi, ILTV was detected in the TG only in 30% and 10% of CL9- and SA2-infected birds, respectively. Tracheal organ co-cultures from 30% and 70% of CL9- and SA2-infected birds, respectively, were negative for ILTV DNA at cull but yielded quantifiable DNA within 6 days post-explant (dpe). TG co-cultivation from 30% and 40% of CL9-and SA2-infected birds, respectively, had detectable ILTV DNA within 6 dpe. Latency characteristics did not substantially vary based on the strain of virus inoculated or between sampling timepoints. These results advance our understanding of ILTV latency and reactivation.

RESEARCH HIGHLIGHTS

• Following inoculation, latent ILTV infection was detected in a large proportion of chickens, irrespective of whether a field or vaccine strain was inoculated.

• In vitro reactivation of latent ILTV was readily detected in tracheal and trigeminal ganglia co-cultures using PCR.

• ILTV latency observed in SPF chickens at 21 days post-infection was not substantially different to 35 days post-infection.

     

The relative locations of the supraorbital,infraorbital, and mental foramina: A cadaveric study

The purpose of this study is to investigate the applicability of the current surgical guideline stating that the main facial foramina that transmit cutaneous nerves to the face (supraorbital notch/foramen, infraorbital foramen, and mental foramen) are equidistant from the midline in European and Hispanic populations. Previous studies suggest this surgical guideline is not applicable for all ethnicities; however, to our knowledge, no data have been published regarding the accuracy of this guideline pertaining to the Hispanic population. An experimental study was performed on 67 cadavers donated to the Human Anatomy Program at UT Health San Antonio. The supraorbital, infraorbital, and mental foramina were dissected and midline structures including the crista galli, internasal suture, anterior nasal spine, and mandibular symphysis were identified. The distance from each foramen to midline was recorded using a digital caliper. For all cadavers/ethnicities studied, the supraorbital, infraorbital, and mental foramina were 25.32 mm, 29.57 mm, and 25.55 mm to the midline, respectively. Thus, the infraorbital foramen is located significantly more lateral compared to the supraorbital (p < 0.0001) and mental foramina (p < 0.0001). After dividing the sample based on ethnicity, this relationship was also true for the European sample and tended to be true for the Hispanic sample. Significant anatomical variations exist in the current surgical guideline stating that the supraorbital foramen, infraorbital foramen, and mental foramen are equidistant from the midline. Clinicians may need to adjust their methodology during surgical procedures of the face in order to optimize patient care.     

Histopathological findings of endometrial specimens in abnormal uterine bleeding

Purpose

The aim of this study was to assess the frequency of different histopathological findings obtained from dilatation and curettage (D&C) specimens in patients with abnormal uterine bleeding (AUB).

Methods

In a retrospective review of 591 specimens, the included subjects were all women with AUB who underwent D&C between 2002 and 2006 in Be’sat Hospital, Tehran, Iran. The pathological diagnoses were analyzed in four groups from normal to malignant endometrium. The pathological groups were evaluated for patients’ characteristics including demographic data and medical history.

Results

The majority of patients (61.6 %) were in the 41–50 year age group. Totally, 81.4 % of patients had normal pathology. The disordered proliferative endometrium/polyps, hyperplasia, and malignant pathology were found in 15.4, 2.5, and 0.7 % of specimens, respectively. The abnormal pathologies were seen more among patients with postmenopausal status, nulli-/primigravid women, and those with hypertension, diabetes, hypothyroidism, and polycystic ovary syndrome.

Conclusions

The proliferative endometrium and secretory endometrium were the most common histopathological observations in AUB patients in our region, and except normal endometrium, disordered proliferative endometrium was the most common cause of AUB.     

Study of the normal internal organ weights in Tehran’s population

ObjectiveExamine the normal adult internal organ weight and its relationship with body height, body weight, body mass index and age.Materials and methodsProspective analysis of data from 1222 autopsies in Legal Medicine Organization of Iran from 1st January, 2007 to 1st September, 2008. All the subjects were adult residents of Tehran died from external causes and showed no pathological changes.ResultsThe weight of the brain, heart, lungs, liver, spleen, pancreas, kidneys, thyroid gland, the pituitary gland, the suprarenal glands, testes, prostate, ovaries and the uterus were collected from 914 males and 308 females between 15 and 88 years. The weight of all the organs was correlated statistically with at least one external parameter with the exception of the pancreas in men, the uterus, the spleen and the thyroid in women. Organ weights decreased with age except for the heart and the prostate, and increased in relation to body height and/or BMI. Except for the brain, the organ weight showed a better statistical correlation with the BMI than the body height.ConclusionThese results can be used as standard organ weights to determine abnormal evidences in Forensic and Pathologic corpses. However such results have to be regularly updated by pathologists in order to keep organ weight as a good criterion used in postmortem diagnosis.     

Host Genome,Epigenome, and Oral Microbiome Interactions: Toward Personalized Periodontal Therapy

Periodontal diseases are multidimensional and complex. Bacterial content is the initiator, but disease progression depends on genetic and environmental parameters related to the host. Although bone loss magnitude is the common resulting outcome, the biologic process likely represents a unique inflammatory response characteristic to every individual. Therefore, it is obvious that practitioners must take into account the influence of these parameters and tailor a treatment accordingly. New, emerging deoxyribonucleotide‐based technologies allow integration of the biologic impact of the environment, and periodontists should be prepared to incorporate these technologies into their practice to advance personalized medicine. This commentary provides updated insights on the distinctiveness of inflammation per individual in terms of microbiome and genome specificity and cites some educational resources helpful for implementing individualized therapy.     

Influence of surface modification techniques on shear bond strength between different zirconia cores and veneering ceramics

PURPOSE

Veneering porcelain might be delaminated from underlying zirconia-based ceramics. The aim of this study was the evaluation of the effect of different surface treatments and type of zirconia (white or colored) on shear bond strength (SBS) of zirconia core and its veneering porcelain.

MATERIALS AND METHODS

Eighty zirconia disks (40 white and 40 colored; 10 mm in diameter and 4 mm thick) were treated with three different mechanical surface conditioning methods (Sandblasting with 110 µm Al₂O₃ particle, grinding, sandblasting and liner application). One group had received no treatment. These disks were veneered with 3 mm thick and 5 mm diameter Cercon Ceram Kiss porcelain and SBS test was conducted (cross-head speed = 1 mm/min). Two and one way ANOVA, Tukey''s HSD Past hoc, and T-test were selected to analyzed the data (α=0.05).

RESULTS

In this study, the factor of different types of zirconia ceramics (P=.462) had no significant effect on SBS, but the factors of different surface modification techniques (P=.005) and interaction effect (P=.018) had a significant effect on SBS. Within colored zirconia group, there were no significant differences in mean SBS among the four surface treatment subgroups (P=0.183). Within white zirconia group, "Ground group" exhibited a significantly lower SBS value than "as milled" or control (P=0.001) and liner (P=.05) groups.

CONCLUSION

Type of zirconia did not have any effect on bond strength between zirconia core and veneer ceramic. Surface treatment had different effects on the SBS of the different zirconia types and grinding dramatically decreased the SBS of white zirconia-porcelain.     

Phosphodiesterase Type 5 Inhibitor Treatment for Erectile Dysfunction in Patients with End-Stage Renal Disease Receiving Dialysis or After Renal Transplantation

IntroductionThe phosphodiesterase type 5 (PDE5) inhibitors are generally well tolerated and effective for treating erectile dysfunction (ED), including in patients with significant comorbidity. Because of this benign safety profile, investigators have used PDE5 inhibitors to treat patients with ED and severe renal disease or those who have received renal transplants.AimTo assess safety and efficacy of PDE5 inhibitors in patients receiving dialysis or renal transplants.Main Outcome MeasuresErectile function as assessed by the International Index of Erectile Function (IIEF) and Global Assessment Questions; adverse events (AEs).MethodsWe reviewed published studies of PDE5 inhibitors in patients receiving dialysis or renal transplants.ResultsIn double-blind, placebo-controlled studies in patients receiving dialysis or renal transplants, sildenafil significantly improved erectile function as assessed by the IIEF, and 75–85% of patients reported improved erectile function on Global Assessment Questions; efficacy was more variable in less well-controlled studies. In >260 patients undergoing dialysis who received sildenafil in clinical studies, there were only six reported discontinuations because of AEs (headache [N=3], headache and nausea [N=1], gastrointestinal [N=1], and symptomatic blood pressure decrease [N=1]). In approximately 400 patients with renal transplants who received sildenafil, only three patients discontinued because of AEs. Vardenafil improved IIEF scores of up to 82% of renal transplant recipients in randomized, controlled studies (N=59, total), with no reported discontinuations because of AEs. Limited data also suggest benefit with tadalafil.Conclusions.ED is common in patients undergoing renal dialysis or postrenal transplant and substantially affects patient quality of life. Sildenafil and vardenafil appear to be efficacious and well tolerated in patients receiving renal dialysis or transplant. Lasaponara F, Sedigh O, Pasquale G, Bosio A, Rolle L, Ceruti C, Timpano M, Negro CLA, Paradiso M, Abbona A, Segoloni GP, and Fontana D. Phosphodiesterase type 5 inhibitor treatment for erectile dysfunction in patients with end-stage renal disease receiving dialysis or after renal transplantation. J Sex Med 2013;10:2798–2814.     

Biofunctionalized peptide-based hydrogel as an injectable scaffold for BDNF delivery can improve regeneration after spinal cord injury

Background

The complex pathophysiological events occurring after traumatic spinal cord injuries (TSCI) make this devastating trauma still incurable. Peptide amphiphile (PA) hydrogels are nanobiomaterials displaying desirable properties for application in regenerative medicine because they are absorbable, injectable, allowing biofunctionalization, controlling release of trophic factors and mimic extracellular matrix (ECM). In this study, we explored the potentiality of the IKVAV-functionalized PA hydrogel to provide a permissive environment for cell migration and growth as well as sustained release of BDNF at the lesion after severe compression injury model.

Acute coronary syndrome following arteriovenous fistula creation in a post CABG patient: A steal phenomenon from coronary artery to subclavian artery

A 70‐year‐old man with a history of coronary artery bypass grafting 15 years back and arteriovenous (AV) fistula creation in the left arm 1 month back presented with acute coronary syndrome (ACS). He had not received dialysis before his referral. We felt the most likely etiology for these complaints was increased cardiac oxygen demand from an increased cardiac output related to the newly formed left AV fistula. Coronary angiography was done to detect any significant stenosis in the native or grafted vessels. This revealed that the left subclavian artery was totally occluded in the ostioproximal segment and the coronary arteries did not have occlusions to explain the ACS setting. CT angiography confirmed the angiographic findings of the totally occluded left subclavian artery followed by a well‐developed and patent left internal mammary artery to left anterior descending artery. This led to the consideration of a steal syndrome from the coronary artery by the subclavian artery distal to the occlusion. A successful percutaneous endovascular intervention on the left subclavian artery occlusion was performed. Subsequently, the patient became asymptomatic and experienced a dramatic increase in left ventricular ejection fraction.