Transmission electron microscopy of the retina following thyroidectomy in rabbit

Thyroid hormones play a crucial role in the neuroretinal maturation of the eye and central nervous system development. An experiment was conducted to survey the effects of thyroidectomy on rabbit retina. In this study, 10 male rabbits of New Zealand strips were divided into two groups of five animals each (control group and thyroidectomy group). Before surgery, the rabbits were maintained in 12-h light and 12-h dark. The animals were anesthetized with intraperitoneal injection of 10 mg/kg xylazine and 6 mg/kg ketamine, and bilateral thyroidectomy was performed. One and 2 weeks after surgery, the rabbits were sacrificed by humane methods. Then, retinas of the killed rabbits were isolated in the laboratory and examined by electron microscopy for evaluating cells and changes in inner segment, outer segment, outer limiting membrane, and outer nuclear layer. The result of this experiment showed vacuolization in inner section and endoplasmic reticulum of rabbit retina in group two. It was also observed that mitochondria of the inner segment of retina were larger and more circular than mitochondrial in control group; moreover, most of them had lost their crystal. The core in the control group was normal and had round to oval shape and distributed chromatin, but in thyroidectomy group, the mode of the nucleus was small and dark (pyknosis) and some nucleus had been destroyed.     

GJB2 mutations in Iranians with autosomal recessive non-syndromic sensorineural hearing loss

Hereditary hearing loss (HHL) is an extremely common disorder. About 70% of HHL is non-syndromic, with autosomal recessive forms accounting for approximately 85% of the genetic load. Although very heterogeneous, the most common cause of HHL in many different world populations is mutations of GJB2, a gene that encodes the gap junction protein connexin 26 (Cx26). This study investigates the contribution of GJB2 to the autosomal recessive non-syndromic deafness (ARNSD) load in the Iranian population. One hundred sixty eight persons from 83 families were studied. GJB2-related deafness was diagnosed in 9 families (4, 35delG homozygotes; 3, 35delG compound heterozygotes; 1, W24X homozygote; 1, non-35delG compound heterozygote). The carrier frequency of the 35delG allele in this population was approximately 1% (1/83). Because the relative frequency of Cx26 mutations is much less than in the other populations, it is possible that mutations in other genes play a major role in ARNSD in Iran.     

Effect of different frequencies of repetitive transcranial magnetic stimulation on acquisition of chemical kindled seizures in rats

In the current study we investigated the effect of repetitive transcranial magnetic stimulation (rTMS) at different frequencies on chemical kindling in rats. Chemical kindling was induced by injection of pentylenetetrazol (PTZ; 45 mg/kg) at the intervals of 48 h between the injections. In the first experiment, effect of 0.25, 1 and 5 Hz rTMS (four trains of 4 s at motor threshold intensity) on kindling acquisition was investigated. In the second experiment, the stability of rTMS effects was checked in animals of the first experiment during a follow-up period of 2 weeks. Animals received a single dose of PTZ at 7th and 14th day after the last PTZ injection (12th injection) and their seizure parameters were recorded. Obtained results showed that application of rTMS at the frequencies of 0.25 and 1 Hz had anticonvulsant effect and decreased the PTZ kindling acquisition. However, when applied at the frequency of 5 Hz, it had an increasing effect on PTZ kindling rate. During the follow-up study, the seizure severity increased in animals treated with 0.25 Hz rTMS (and somehow in animals treated with 1 Hz rTMS), but did not change in animals treated with 5 Hz rTMS compared to the 12th PTZ injection. Our results showed that rTMS application may have an anticonvulsant effect during chemical kindling acquisition at very low frequency (0.25 Hz) and can increase the seizure severity at high frequency (5 Hz). However, during follow-up, the anticonvulsant effects of rTMS may be converted to proconvulsive effects.     

The incidence of humeral bone resorption in uncemented reverse shoulder arthroplasty and the impact on functional outcomes

BackgroundFull-thickness bone resorption around the humeral stem in shoulder arthroplasty is an increasingly recognized phenomenon, but the impact on outcomes remains unclear. This study aims to investigate prevalence of bone resorption in patients with the Zimmer-Biomet Comprehensive reverse shoulder arthroplasty and the impact on the functional outcomes.MethodsA retrospective analysis was carried out on 65 consecutive patients with primary reverse total shoulder arthroplasty using the Comprehensive Shoulder System from 2014 to 2020, with a minimum of 12-month follow-up. The prevalence of humeral bone resorption was graded from 0 to 4, and risk factors for these changes and their impact on functional outcomes were further investigated.ResultsThe majority of patients (75%) were female with an average age of 75 years (53-93), with an overall average follow-up of 26 months (12-60). Bone resorption occurred in 53 patients (82%), and full-thickness bone resorption occurred in only 8 patients (12%). Metaphyseal bone (zones 1 and 7) is mostly at the risk of high-grade resorption. There was no difference in the final Oxford Shoulder Score between patients who had differential resorption grades from 0 to 4 (P = .5742). None of the risk factors from the previous literature including age, sex, indication for surgery, rotator cuff tear and repair, and intramedullary occupation ratio of the implant showed any impact on the rate of resorption.ConclusionFull-thickness humeral bone resorption occurred in approximately 12% of patients when using the Comprehensive reverse shoulder arthroplasty, but it has no impact on the functional outcomes or revision rate in the short-to-medium term.     

The first successful pregnancy following injection of testicular round spermatid in Iran

The authors report the healthy delivery of the first successful round spermatid injection in Iran. The male was a 40-year-old with nonobstructive azoospermia whose previous testicular biopsy revealed only round spermatids. The wife was a 29-year-old healthy woman.