Differential loss of neuromuscular connections according to activity level and spinal position of neonatal rabbit soleus motor neurons

We have tested whether the ability of synapses to compete for occupancy of endplates during neuromuscular synapse elimination is affected by differences in the spinal position or in the activity level of the parent motor neuron. To test the role of spinal position, the relative sizes of motor units for motor neurons from middle and extreme (rostral/caudal) positions in the rabbit soleus motor pool were determined at 3 postnatal ages: 4-5 d ("early" ages, when the soleus is heavily polyinnervated), 8-9 d ("intermediate"), and 11-15 d ("late," when the soleus has just reached singly innervated state). Average motor unit sizes from extreme ventral roots were similar to those from middle ventral roots in early-aged soleus muscles but were significantly smaller (by 18-27%) for both intermediate and late muscles. Thus, motor neurons from extreme positions evidently compete less effectively for retention of synapses than those from middle positions. To test the role of differential activity, inactive and active synapses were pitted directly against one another by implanting Silastic plugs laden with tetrodotoxin (TTX) into one of the spinal nerves containing a minority of the soleus motor axons. Differential activity was maintained during a period of extensive synapse loss, from the time of the implant at day 4 or 5 until the intermediate age (day 8-9). Motor unit twitch tensions were subsequently measured to determine the relative number of synapses retained by individual active and inactive motor neurons. The inactivated motor units were on average significantly larger (by more than 50%) than the corresponding group from normal and control-implanted animals. The abnormally large size of inactivated motor units persisted in animals allowed to recover from the TTX block and examined after multiple innervation had disappeared. Hence, the effect of the TTX block cannot be attributed to a simple slowing of synapse elimination specifically among the inactive motor neurons. We conclude that complete presynaptic inactivity improves the chances of survival relative to that for normal activity during synapse elimination in the neonatal rabbit soleus muscle. This difference in competitive ability may contribute to the development of an important characteristic of adult muscles, the correlation between motor unit size and recruitment threshold.     

Uterine septum structure and reproductive performance: Role of 3D TVUS and MRI

Objective

To evaluate the role 3D TVUS and MRI in diagnosing the nature of uterine septum according to the reproductive performance with histopathological examination as the reference standard.

Patients and methods

The study included 36 patients in the reproductive age presented with infertility or recurrent pregnancy loss, and diagnosed hysteroscopically with double uterine cavity. All patients were subjected to 3D TVUS. Cases in which the diagnosis of septate uterus was not confirmed by 3DUS were excluded from the study. The remaining 29 patients confirmed to have uterine septum partial or complete were included. 3D TVUS with VOCAL, was applied in order to calculate the volume of the septum, echostructure and its vascularity index (VI). The patients were then referred to MRI examination, patients were referred to operative hysteroscopy for hysteroscopic metroplasty. Sample of septal tissue was obtained and sent for histopathological examination.

Results

The Vascularity index (VI) of the muscular septum (16.63 ± 5.7%) was significantly higher than the fibrous septum (3.6 ± 1.17%). The sensitivity, specificity, PPV, and NPV in diagnosing septate uterus were 100%, 90 %, 95%, and 100% for 3D TVUS, and 95%, 80%, 90%, and 89% for MRI respectively.

Conclusion

3D TVUS is an accurate, less expensive, and a rapid examination than MRI in diagnosing uterine septa structure, it can be considered as the reference standard in diagnosing and characterizing septate uterus.     

Combined estrogen and ghrelin administration restores number of blood vessels and collagen type I/III ratio in the urethral and anal canal submucosa of old ovariectomized rats

We compare the effects of estrogen and/or ghrelin on vascular counts and collagen I/III ratio of urethral and anal canal submucosa in old vs young-adult ovariectomized rats. Ovariectomized Fisher 344 rats (18 and 3 months old, n = 24 x 2) received 42 daily intraperitoneal 17-ss estradiol (10 microg/kg), ghrelin (2 microg/kg), both, or vehicle (n = 6 x 4 per group). Blood vessel counts and collagen I/III ratio were measured, respectively, by light microscopy and Western blot analysis with immunohistochemistry of ghrelin receptors. Estrogen significantly increased urethral and anal vascular counts and collagen I/III ratio in young-adult rats. In old rats, only combined estrogen/ghrelin administration significantly increased both variables. This was not observed with estrogen or ghrelin separately. Ghrelin receptors were immunostained in urethral and anal submucosa of all samples. Combined estrogen/ghrelin administration restored postovariectomy urethral and anal canal submucosal vessel number and collagen I/III ratio in old rats suggesting independent ageing effect.     

Evaluation of the policy of secondary prevention against rheumatic fever among Egyptian children

Objective

We evaluated the effectiveness of long acting penicillin (LAP) as a 2-weekly regimen in winter and a 3-weekly regimen in summer for prevention of streptococcal colonization and also studied the common complaints of patients during the period of compliance for LAP administration. We also attempted to determine the incidence of relapses or recurrence of rheumatic fever (RF) after the onset of first episode of RF.

Patients & methods

210 rheumatic patients with good compliance to LAP (for at least one year) were included in the study. Demographic, clinical information, patients'' complaints and echocardiographic data of rheumatic patients were collected both retrospectively and prospectively. Anti-streptolysin O titre (ASOT) and throat swab culture were done at the end of the study (on Day 14 in the 2-weekly regimen and on Day 21 in the 3-weekly regimen).

Results

The age of onset of rheumatic fever was mostly between 5 and 15 years and the youngest patient was 2 years old. Subclinical carditis (SCC) was present in 79 (37%) of all the patients in the study population. Only 7 patients (3.3%) had a relapse within 2 years of the acute episode of RF. At the end of the study, ASOT was found to be high only in 11 patients (5.2%) and throat swab cultures were found negative in all patients

Conclusion

LAP regimen is fairly effective in eradicating streptococcal colonization. The incidence of relapse of RF within 2 years of the acute episode of RF is relatively low.     

Morphological and Histochemical Description of Quail Feather Development

The current study investigated the macroscopic and microscopic differences between pennaceous and plumulaceous feathers. The morphology of the barbules distinguished pennaceous and plumulaceous feathers, particularly the shape of barbules during their development. In pennaceous feathers, the initial barbules were large and elongated or pyriform in shape, while plumulaceous feathers had small, thin, elongated initial barbules. The spinous barbules were characteristic of pennaceous feathers. The histochemical reactivity of both feather types for Mallory trichrome, orange G, and acridine orange, safranin O, PAS, and methylene blue was determined. Keratin was detected by Mallory trichrome, orange G, and acridine orange. In conclusion, the histochemical properties of pennaceous and plumulaceous feathers of quail, particularly the distribution and nature of keratin during development, should be considered in future studies. The unique morphological features of pennaceous and plumulaceous feathers could be used as a guide for phylogenetic identification. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1865–1883, 2020. © 2019 American Association for Anatomy     

Does influenza vaccination help reduce incidence of COVID-19 infection among hospital employees?

To facilitate the understanding of the interaction between severe acute respiratory syndrome coronavirus 2 causing the corona virus disease 2019 (COVID-19) and other pathogens causing respiratory system affection we investigated the effect of influenza vaccination on the incidence and severity of COVID-19 among members of staff working in the Bahrain Defense Force Hospital.All staff members working in the hospital between February 2020 and March 2021 were divided into 2 main groups based on whether or not they received influenza vaccination. None of the participants had received any of the COVID-19 vaccines throughout this time period. The records of each were scrutinized to see the effect of influenza vaccination on incidence and severity of COVID-19. Severity measures were: need for hospital and intensive care unit admission and total length of hospital stay.Incidence of affection with COVID-19 was much lower in the vaccinated group (3.7% vs 8.1%, P < .001). Influenza vaccination also reduced total length of hospital stay (6.2 days vs 12.7 days, P < .05) and need for intensive care unit admission among the patients.Influenza vaccine reduces both the incidence of affection as well as the overall burden of COVID-19. This is of particular importance for people working in the healthcare field during the serious COVID-19 pandemic.     

Magnesium ascorbyl phosphate vesicular carriers for topical delivery; preparation,in-vitro and ex-vivo evaluation,factorial optimization and clinical assessment in melasma patients

Ascorbic acid (vitamin C) is an antioxidant that is widely used in cosmetics in skincare products. Due to the excessive low stability of ascorbic acid in cosmetic formulations, the stabilized ascorbic acid derivative, magnesium ascorbyl phosphate (MAP) was formulated as vesicular carriers; ethosomes and niosomes. The aim was to deliver MAP at the intended site of action, the skin, for sufficient time with enhanced permeation to get an effective response. Ethosomes were formulated using a full 3² factorial design to study ethanol and phospholipid concentration effect on ethosomes properties. Niosomes were formulated using 2³ factorial designs to study the effect of surfactant type, surfactant concentration and cholesterol concentration on niosomes properties. The prepared formulations were evaluated for their Entrapment efficiency, particle size, polydispersity index, zeta potential and % drug permeated. The optimized ethosomal and niosomal formulations were incorporated into carbopol gel and evaluated for their permeation, skin retention and stability. A comparative split-face clinical study was done between the ethosomal and niosomal formulations for melasma treatment using Antera 3 D^® camera. The optimized ethosomal and niosomal gels showed comparable controlled permeation and higher skin retention over their ethosomes and niosomes formulations respectively. Magnesium ascorbyl phosphate ethosomal gel showed clinically and statistically significant melanin level decrease after one month while MAP niosomal gel showed clinically and statistically significant melanin level decrease after six months. A combination of MAP ethosomes and niosomes could be promising skincare formulations for melasma and hyperpigmentation short and long-term treatment.     

Estimating seroprevalence of herpes simplex virus type 1 among different Middle East and North African male populations residing in Qatar

HSV‐1 epidemiology in the Middle East and North Africa (MENA) remains poorly understood. Our study aimed to measure HSV‐1 antibody prevalence (seroprevalence) and its age‐distribution among select MENA populations residing in Qatar. Sera were collected from male blood donors attending Hamad Medical Corporation 2013‐2015. A total of 2,077 sera were tested for anti‐HSV‐1 antibodies using HerpeSelect^® 1 ELISA IgG kits (Focus Diagnostics, Cypress, CA). Robust Poisson regression was conducted to estimate adjusted infection prevalence ratios. Country‐specific HSV‐1 seroprevalence was estimated for 10 national populations: 97.5% among Egyptians, 92.6% among Yemenis, 90.7% among Sudanese, 88.5% among Syrians, 86.5% among Jordanians, 82.3% among Qataris, 81.4% among Iranians, 81.4% among Lebanese, 80.5% among Palestinians, and 77.0% among Pakistanis. Age‐specific HSV‐1 seroprevalence was estimated for Egypt, the Fertile Crescent (Iraq, Jordan, Lebanon, Palestine, and Syria), and Qatar. Seroprevalence increased with age among Fertile Crescent and Qatari nationals. Seroprevalence increased from 70.0% among those aged ≤ 24 years up to 98.0% among those aged ≥55 years among Fertile Crescent nationals. Seroprevalence was consistently above 90% for all ages among Egyptians. HSV‐1 seroprevalence is high in MENA, though with some variation across countries. The seroprevalence appears to have declined among current young age cohorts compared to its levels a few decades ago.