Radium deposition in human brain tissue: A Geant4-DNA Monte Carlo toolkit study.

NASA has encouraged studies on 226Ra deposition in the human brain to investigate the effects of exposure to alpha particles with high linear energy transfer, which could mimic some of the exposure astronauts face during space travel. However, this approach was criticized, noting that radium is a bone-seeker and accumulates in the skull, which means that the radiation dose from alpha particles emitted by 226Ra would be heavily concentrated in areas close to cranial bones rather than uniformly distributed throughout the brain. In the high background radiation areas of Ramsar, Iran, extremely high levels of 226Ra in soil contribute to a large proportion of the inhabitants' radiation exposure. A prospective study on Ramsar residents with a calcium-rich diet was conducted to improve the dose uniformity due to 226Ra throughout the cerebral and cerebellar parenchyma. The study found that exposure of the human brain to alpha particles did not significantly affect working memory but was significantly associated with increased reaction times. This finding is crucial because astronauts on deep space missions may face similar cognitive impairments due to exposure to high charge and energy particles. The current study was aimed to evaluate the validity of the terrestrial model using the Geant4 Monte Carlo toolkit to simulate the interactions of alpha particles and representative cosmic ray particles, acknowledging that these radiation types are only a subset of the complete space radiation environment.

Comparative characteristics of mesenchymal stem cells derived from reamer-irrigator-aspirator, iliac crest bone marrow, and adipose tissue.

Mesenchymal stem cells (MSCs) have been considered promising tools for new clinical concepts in supporting cellular therapy and regenerative medicine. More recently, Ream/Irrigator/Aspirator (RIA) was introduced as a source of MSCs. In this study we compared MSCs derived from three different sources (iliac crest bone marrow (ICBM), adipose tissue (AT), and (RIA)) regarding the morphology, the success rate of isolating MSCs, colony frequency, expansion potential, osteogenic and chondrogenic differentiation capacity. MSCs were isolated from three different sources and flow cytometric analyses were performed for cell characterization. Colony-forming unit-fibroblast (CFU-F) assay and population doubling time (PDT) were evaluated for MSCs derived from three different sources and differentiation potential of RIA, ICBM-, and AT-MSCs were determined by staining. Additionally, gene expression profiles for tissue specific markers corresponding to osteogenesis and chondrogenesis were analyzed using real time polymerase chain reaction (RT-PCR). Cultured with the appropriate condition, osteogenic and chondrogenic differentiation could be confirmed in all MSC preparations. Flow cytometry analysis indicated that RIA- and AT-derived MSCs have more homogenous populations than ICBM-MSCs. A comparison of the colonogenic ability in different tissues by CFU-F assay after 10 days showed that more colonies are formed from RIA-MSCs than from ICBM-MSCs, and AT-MSCs. AT-MSCs, were dispersed with no obvious colonies. The RIA-MSCs underwent osteogenesis and chondrogenesis at a faster rate than ICBM and AT-MSCs. Direct comparisons of RIA- to ICBM- and AT-MSCs have shown the RIA-MSCs have higher differentiation toward osteoblast and chondrocytes compared to other sources of MSCs. Hence, RIA-MSCs may be recommended as a more suitable source for treating orthopedic disorders.

Treatment of trichostasis spinulosa with a 755-nm long-pulsed alexandrite laser.

BACKGROUND: Trichostasis spinulosa (TS) is a common disorder of hair follicle, characterized by spinous plugs. Topical treatments offer temporary relief but permanent removal of the abnormal follicles using hair removal lasers may result in a definite cure. OBJECTIVE: To evaluate the safety and efficacy of 755-nm alexandrite laser for the treatment of TS lesions. PATIENTS AND METHODS: Two consecutive 755-nm alexandrite laser treatments were performed one month apart. The clinical response and adverse effects were assessed four weeks after the first and second treatments and 20 weeks after the second treatment. RESULTS: Thirty one patients with skin phototypes II to IV completed the study. At the last follow up visit, a decrease in dark-plug density of greater than 50% was noted in 16 patients (51.3%), while only three patients (9.7%) had an improvement of greater than 75%. Ten of the 21 patients (47.6%) with skin type III and six of the seven patients (85.7%) with skin type IV achieved at least 50% improvement in lesions at the last follow up visit (P = 0.1). CONCLUSION: The 755-nm alexandrite laser can safely and effectively reduce TS lesions lasting for a relatively long time in patients with skin types III-IV.

Psycho-cutaneous disorders: an epidemiologic study.

BACKGROUND AND AIMS: Psycho-dermatology addresses the interaction between mind and the skin. Effective management of at least one third of the patients attending the skin department depends, to some extent, upon the recognition of emotional and psychologic factors. The aim of this study was to provide epidemiologic data about common psycho-dermatoses and their prevalence in dermatologic patients in Iran. MATERIALS AND METHODS: Patients suspicious to have psychocutaneous problem with primary dermatologic chief complaint were included. After detailed dermatologic evaluation, all patients were visited by an expert psychologist to determine prevalence of DSM-IV disorders in each psychocutaneous category including delusion of parasitosis, trichotillomania, dermatitis artefacta and neurotic excoriation. RESULTS: A total of 178 patients including 78 (43.8%) males and 100 (56.2%) females entered the study. The commonest psychocutaneous disorder was neurotic excoriation followed by trichotillomania, delusion of parasitosis and dermatitis artefacta. Mood disorder was the commonest DSM-IV disorder in our patients, then anxiety disorder and drug-induced symptoms. CONCLUSION: According to our results, it seems that all psychocutaneous disorders but delusion of parasitosis are commoner in females. Mood and anxiety disorders were common in patients with dermatitis artefacta, as patients with neurotic excoriation. In trichotillomania, obsessive compulsive disorder was the commonest disorder. Drug abuse is a major background of delusional parasitosis.

Cervicovaginal involvement in pemphigus vulgaris: a clinical study of 77 cases.

BACKGROUND: Pemphigus vulgaris (PV) is an autoimmune blistering disease which is known to involve the female genital tract, but the frequency at which this occurs is unknown. There are few reports in the literature of the cytological appearance of PV on cervicovaginal smears. OBJECTIVES: To evaluate involvement of the female genital tract and the appearance of cervicovaginal Papanicolaou (Pap) smears in PV. METHODS: The study included 77 patients with PV who attended between April 2005 and February 2007. Each patient was subjected to gynaecological examination and cervicovaginal Pap smear. RESULTS: Genital lesions were observed in 39 patients (51%). Of these, the labia minora were involved in 36 patients (92%), the labia majora in 11 (28%), the vagina in 14 (36%) and the cervix in six (15%). Cervicovaginal Pap smears of 20 of 77 patients (26%) showed PV. Of 72 satisfactory Pap smears, the cervical Pap smear was normal in 25 patients (35%), inflammatory in 43 patients (60%), and dysplastic (low-grade squamous intraepithelial neoplasia) in four patients (6%). CONCLUSIONS: Involvement of the female genital tract with PV might not be as infrequent as was previously thought; it is probably the second most common mucosal site of PV after the oral mucosa. Genital lesions may be missed and the need for thorough pelvic examination should not be overlooked.

Oculocutaneous tyrosinaemia or tyrosinaemia type 2: a case report.

Oculo-cutaneous tyrosinaemia type II is an autosomal recessive disease due to an abnormality of tyrosine metabolism, probably because of a deficiency of cytoplasmic tyrosine aminotransferase. It presents as a varying association of focal palmoplantar keratosis, bilateral keratitis and mental retardation. Herein, we report an 8-year-old boy with palmoplantar hyperkeratosis with peripheral oozing and dendritic keratitis appearing after the skin lesions. There was no mental deterioration despite the long delay in diagnosis of the disorder. The diagnosis was confirmed by the presence of hypertyrosinaemia and the absence of hepatorenal lesion. The child exhibited a remarkable degree of improvement in the hyperkeratotic lesions and keratitis after the dietary modifications were instituted. In conclusion, chronic focal bullous palmoplantar hyperkeratosis along with keratitis should alert the clinician to screen for abnormal serum and/or urine tyrosine level. Awareness of the presenting signs and symptoms may speed up the diagnosis and initiation of a tyrosine and phenylalanine-restricted diet that is most efficient in improving the symptoms and preventing visual and cognitive impairment.

Terson's syndrome--significance of ocular findings.

Ocular findings of three patients with Terson's syndrome are presented. Two patients had a ruptured intracranial aneurysm, and one had a subdural hematoma. Ocular findings included retinal, preretinal, and vitreous hemorrhages. Vitreous hemorrhage may be delayed in onset and may require vitrectomy if persistent. The eye findings are characteristic but not pathognomonic of this syndrome. The authors emphasize the diagnostic and prognostic importance of ocular findings in patients with spontaneous intracranial hemorrhages. Some of the primary theories of the syndrome are reviewed.

Vitreoretinal degeneration in spondyloepiphyseal dysplasia congenita.

Eighteen patients had ocular changes associated with spondyloepiphyseal dysplasia congenita, a rare cause of congenital dwarfism with normal mental development. Seven patients had nonprogressive myopia of 5.00 or more diopters. Vitreoretinal degeneration was encountered in six patients with high myopia, and vitreous syneresis was present in all patients. Corrected visual acuity was 20/50 or better in all patients. Retinal detachment was not encountered, although reports in the nonophthalmic literature claim up to 50% retinal detachment rate and poor visual prognosis in these patients.

Effect of isolated inferior oblique muscle myectomy in the management of superior oblique muscle palsy.

Thirty-three patients with superior oblique palsy were treated with an inferior oblique myectomy temporal to the inferior rectus muscle. The mean effect of surgery was 11.91 +/- 1.38 in all positions of gaze and for all age groups. The operative result in both children and adults was the same. The mean effect of surgery correlated with the size of the preoperative hyperdeviation in the fields of action of both inferior and superior oblique muscles. Inferior oblique muscle myectomy was followed by return of normal function to the superior oblique muscle in 63% of cases. Ocular torticollis was eliminated in 90% of the patients. Persistent overaction of inferior oblique muscle was encountered in three patients. Postoperative underaction of the myectomized muscle was not observed in any of our patients. A myectomy is recommended as a primary procedure in patients with superior oblique muscle palsy when the direct antagonist is overacting and the hyperdeviation is 10 to 15 prism diopters or more in primary position or the fields of action of the paretic superior oblique muscle or the overacting inferior oblique muscle.