The presence of a vocal ligament in fetuses: a histochemical and ultrastructural study

Although it is currently believed that the vocal ligament of humans undergoes considerable development postnatally, there is no consensus as to the age at which it first emerges. In the newborn infant, the lamina propria has been described as containing a sparse collection of relatively unorganized fibres. In this study we obtained larynges from autopsy of human fetuses aged 7-9 months and used light and electron microscopy to study the collagenous and elastic system fibres in the lamina propria of the vocal fold. Collagen fibres were viewed using the Picrosirius polarization method and elastic system fibres were stained using Weigert`s resorcin-fuchsin after oxidation with oxone. The histochemical and electron microscopic observations were consistent, showing collagen populations with an asymmetric distribution across different compartments of the lamina propria. In the central region, the collagen appeared as thin, weakly birefringent, greenish fibres when viewed using the Picrosirius polarization method, whereas the superficial and deep regions contained thick collagen fibres that displayed a strong red or yellow birefringence. These findings suggest that the thin fibres in the central region consist mainly of type III collagen, whereas type I collagen predominates in the superficial and deep regions, as has been reported in studies of adult vocal folds. Similarly, elastic system fibres showed a differential distribution throughout the lamina propria. Their distribution pattern was complementary to that of collagen fibres, with a much greater density of elastic fibres apparent in the central region than in the superficial and deep regions. This distribution of collagen and elastic fibres in the fetal vocal fold mirrors that classically described for the adult vocal ligament, suggesting that a vocal ligament has already begun to develop by the time of birth. The apparently high level of organization of connective tissue components in the newborn is in contrast to current hypotheses that argue that the mechanical stimuli of phonation are essential to the determination of the layered structure of the lamina propria and suggests that genetic factors may play a more significant role in the development of the vocal ligament than previously believed.

Direct measurement of instantaneous source speed for a HDR brachytherapy unit using an optical fiber based detector

Purpose: Several attempts to determine the transit time of a high dose rate (HDR) brachytherapy unit have been reported in the literature with controversial results. The determination of the source speed is necessary to accurately calculate the transient dose in brachytherapy treatments. In these studies, only the average speed of the source was measured as a parameter for transit dose calculation, which does not account for the realistic movement of the source, and is therefore inaccurate for numerical simulations. The purpose of this work is to report the implementation and technical design of an optical fiber based detector to directly measure the instantaneous speed profile of a (192)Ir source in a Nucletron HDR brachytherapy unit. Methods: To accomplish this task, we have developed a setup that uses the Cerenkov light induced in optical fibers as a detection signal for the radiation source moving inside the HDR catheter. As the (192)Ir source travels between two optical fibers with known distance, the threshold of the induced signals are used to extract the transit time and thus the velocity. The high resolution of the detector enables the measurement of the transit time at short separation distance of the fibers, providing the instantaneous speed. Results: Accurate and high resolution speed profiles of the 192Ir radiation source traveling from the safe to the end of the catheter and between dwell positions are presented. The maximum and minimum velocities of the source were found to be 52.0 +/- 1.0 and 17.3 +/- 1:2 cm/s. The authors demonstrate that the radiation source follows a uniformly accelerated linear motion with acceleration of vertical bar a vertical bar = 113 cm/s(2). In addition, the authors compare the average speed measured using the optical fiber detector to those obtained in the literature, showing deviation up to 265%. Conclusions: To the best of the authors` knowledge, the authors directly measured for the first time the instantaneous speed profile of a radiation source in a HDR brachytherapy unit traveling from the unit safe to the end of the catheter and between interdwell distances. The method is feasible and accurate to implement on quality assurance tests and provides a unique database for efficient computational simulations of the transient dose. (C) 2010 American Association of Physicists in Medicine. [DOI: 10.1118/1.3483780]

Sonographic appearance of gestational trophoblastic disease evolving into epithelioid trophoblastic tumor

Epithelioid trophoblastic tumor is a distinctive but rare trophoblastic tumor. It derives from intermediate trophoblastic cells of the chorion laeve and is usually associated with a previous gestational event. We report the case of a patient who had undergone dilatation and curettage for a missed miscarriage. Three months later gestational trophoblastic disease was suspected because of persistent vaginal bleeding and high levels of beta-human chorionic gonadotropin (beta-hCG). Transvaginal ultrasound revealed irregular echolucent lacunae within the myometrium, some of them filled with low-resistance, turbulent blood flow on Doppler examination, emphasizing the diagnosis of gestational trophoblastic disease. The patient was treated with 12 courses of multiagent chemotherapy. After a 2-year remission, a low rise in serum beta-hCG was observed. Transvaginal ultrasound revealed a well-circumscribed echogenic lesion with a diameter of 1.8 cm in the uterine fundus, with no detectable blood flow on Doppler imaging. A diagnosis of tumor of intermediate trophoblastic cells was suspected and total hysterectomy was performed. On pathological examination, the histological and immunohistochemical features were characteristic of epithelioid trophoblastic tumor. Most reported cases of epithelioid trophoblastic tumor have solitary nodules with sharp margins, which is consistent with our ultrasound findings. Ultrasound may be helpful in differentiating epithelioid trophoblastic tumor from placental-site trophoblastic tumor, another tumor of intermediate trophoblastic cells, which shows infiltrative growth insinuating between muscle fibers. Copyright (C) 2010 ISUOG. Published by John Wiley & Sons, Ltd.

The Incapacity of the Surgeon to Identify NASH in Bariatric Surgery Makes Biopsy Mandatory

Nonalcoholic steatohepatitis (NASH) is a morbid condition highly related to obesity. It is unclear if the macroscopic liver appearance correlates with the histopathologic findings. The goal of this prospective study was to determine the relationship between the intraoperative liver appearance and the histopathologic diagnosis of NASH in morbidly obese subjects undergoing bariatric surgery. We also aimed to determine variables that could predict NASH preoperatively. Consecutive 51 subjects undergoing bariatric surgery without evidence of other liver disease underwent intraoperative liver biopsy. An intraoperative liver visual (macroscopic and tactile examination) was recorded. The liver aspect was compared with the liver histologic findings. Histological assessment was categorized into two groups: NASH and non-NASH (including normal histology and simple steatosis). Clinical and biochemical parameters were obtained from the patient databases and were compared between groups to identify preoperatively predictive factors of NASH. From 51 patients, only one presented totally normal histology. Forty-three (86.2%) presented simple steatosis, and seven (13.7%) were classified as NASH. Clinical parameters were not different between groups. At biochemical analysis, only VLDL cholesterol level was significantly higher in the NASH group (p = 0.037) but yet within the normal range. Association between macroscopic liver appearance and the presence of histological NASH is poor (sensitivity of 14%, specificity of 56%, positive predictive value of 5%, and negative predictive value of 80%). No predictor of NASH was found. Surgeons` evaluation could not identify NASH individuals. Routine liver biopsy during bariatric operations is mandatory to differentiate NASH and nonalcoholic fatty liver disease.

Monoclonal anti-vascular endothelial growth factor antibody reduces fluid volume in an experimental model of inflammatory pleural effusion

Background and objective: Vascular endothelial growth factor (VEGF) is known to increase vascular permeability and promote angiogenesis. It is expressed in most types of pleural effusions. However, the exact role of VEGF in the development of pleural effusions has yet to be determined. The anti-VEGF mAb, bevacizumab, has been used in the treatment of cancer to reduce local angiogenesis and tumour progression. This study describes the acute effects of VEGF blockade on the expression of inflammatory cytokines and pleural fluid accumulation. Methods: One hundred and twelve New Zealand rabbits received intrapleural injections of either talc or silver nitrate. In each group, half the animals received an intravenous injection of bevacizumab, 30 min before the intrapleural agent was administered. Five animals from each subgroup were sacrificed 1, 2, 3, 4 or 7 days after the procedure. Twelve rabbits were used to evaluate vascular permeability using Evans`s blue dye. Pleural fluid volume and cytokines were quantified. Results: Animals pretreated with anti-VEGF antibody showed significant reductions in pleural fluid volumes after talc or silver nitrate injection. IL-8 levels, vascular permeability and macroscopic pleural adhesion scores were also reduced in the groups that received bevacizumab. Conclusions: This study showed that bevacizumab interferes in the acute phase of pleural inflammation induced by silver nitrate or talc, reinforcing the role of VEGF as a key mediator in the production of pleural effusions. The results also suggest that bevacizumab should probably be avoided in patients requiring pleurodesis.

Inflammation and Remodeling in Infantile, Juvenile, and Adult Allergic Sensitized Mice

Background: Airway structural changes occur early in childhood asthma, but it is unknown whether the development of airway alterations in children is similar to that of adults. We compared inflammation and remodeling parameters in allergic sensitized infantile, juvenile, and adult mice. Methods: Infantile mice (18D) were sensitized with three intraperitoneal injections (i.p.) of ovalbumin (OVA) at days 5 and 7 and challenged with OVA at days 14-16. The 18D1 group received an additional challenge at days 9-11. The juvenile mice (40D) received challenges at days 22-24 and 36-38. Adult mice (100D) were sensitized at days 60-62 and received three inhalations at days 77-79 and 96-98. Animals were submitted to whole body plethysmography. Airway eosinophils, CD3+ T-lymphocytes, IL-5+ cells, mucus content, collagen and reticular fibers density, and smooth muscle thickness were quantified. Results: All sensitized animals presented with airway hyperresponsiveness, without differences in eosinophil cell density The density of CD3+ T-cells was higher in the 100D and 1801 groups than in the 18D and 40D groups. Infantile sensitized groups demonstrated increased interleukin-5 expression in the airways. Infantile mice demonstrated more mucus in the bronchiolar epithelium than the 40D and 100D mice. The 18D animals demonstrated less collagen than the 18D1 group. Juvenile and adult mice had increased airway smooth muscle thickness when compared to age-matched controls, but no differences were observed in the infantile groups. Conclusion: We have shown that infantile mice develop inflammatory and structural alterations in the airways that are partially different from those developed in older animals. Pediatr Pulmonol. 2011;46:650-665. (C) 2011 Wiley-Liss, Inc.

Low doses of silver nitrate induce pleurodesis with a limited systemic response

Background and objective: Both talc and 0.5% silver nitrate have been shown to induce effective pleurodesis. However, acute adverse systemic inflammatory effects have been described with both agents. The aim of this study was to assess in rabbits the systemic effects associated with a new technique of pleurodesis using repeated low doses of 0.1% silver nitrate. Methods: Rabbits were injected intrapleurally through a chest tube with 0.1% silver nitrate at 0, 24 and 48 h. Other groups received a single injection of 0.5% silver nitrate or 400 mg/kg of talc. Blood samples were collected at 24, 48 and 72 h, and at 7 days, and cytological and biochemical measurements were performed. After 28 days, the presence of macroscopic pleural adhesions and microscopic pleural fibrosis in the pleural cavity were evaluated. Results: Both talc and 0.5% silver nitrate caused significant increases in blood neutrophils, serum LDH, IL-8, transforming growth factor-beta and CRP in comparison with control at almost all time points, whereas sequential doses of 0.1% silver nitrate only increased LDH and CRP in the first 24 h and transforming growth factor-beta at all time points. All groups showed efficient pleurodesis, with no differences in pleural adhesions or fibrosis. Conclusions: Sequential doses of 0.1% silver nitrate produced efficient pleurodesis in rabbits, with a low systemic inflammatory response in comparison with 400 mg/kg of talc or 0.5% silver nitrate.

Preliminary findings from a new animal model for Peyronie`s disease involving extracorporeal shock waves

To develop an experimental model in rabbits to analyse the efficiency of extracorporeal shock wave therapy (ESWT) for Peyronie`s disease. We used 15 adult male rabbits divided into three equal groups. In group 1 (no penile ESWT) rabbits had three sessions of ESWT with 2000 shocks each (15 kV), but a rubber mat was placed between the shock head and rabbit to protect the penis; the rabbits were killed at 7 days after the last session of ESWT. In group 2 the rabbits had three sessions of ESWT using the same parameters, and were killed immediately after the last session to analyse the penis. In group 3 the rabbits had three sessions of ESWT as before but were killed at 7 days after the last session, and the penile tissue analysed macroscopically and histologically. The results showed clearly that the model was efficient, creating a similar situation to that when applying ESWT in the human penis. All of the rabbits in groups 2 and 3 had haematomas and diffuse petechiae after ESWT, and only four had urethral and penile bleeding. Almost all macroscopic changes disappeared after 48 h and only one rabbit in group 3 after 7 days had a haematoma on the dorsal penile surface. The histology (assessed using haematoxylin and eosin staining) of the cavernous body of the penis showed: unchanged histology in group 1; in group 2 there was a dilated and congested vascular space in the cavernous body, with interstitial extensive bleeding in the dermis; and in group 3 there was an increase in interstitial fibrous tissue in the cavernous septum, with deposition of collagen fibres and thickening of the tunica albuginea. The present model was efficient in producing tissue injury in the normal penis when treated with ESWT, suggesting that this promising model should be considered for use future studies of Peyronie`s disease.

Oral tolerance attenuates airway inflammation and remodeling in a model of chronic pulmonary allergic inflammation

We investigated the effects of oral tolerance (OT) in controlling inflammatory response, hyperresponsiveness and airway remodeling in guinea pigs (GP) with chronic allergic inflammation. Animals received seven inhalations of ovalbumin (1-5 mg/mL-OVA group) or normal saline (NS group). OT was induced by offering ad libitum ovalbumin 2% in sterile drinking water starting with the 1st ovalbumin inhalation (OT1 group) or after the 4th (OT2 group). The induction of OT in sensitized animals decreased the elastance of respiratory system (Ers) response after both antigen and methacholine challenges, peribronchial edema formation, eosinophilic airway infiltration, eosinophilopoiesis, and airways collagen and elastic fiber content compared to OVA group (P < 0.05). The number of mononuclear cells and resistance of respiratory system (Rrs) responses after antigen and methacholine challenges were decreased only in OT2 group compared to OVA group (P < 0.05). Concluding, our results show that inducing OT attenuates airway remodeling as well as eosinophilic inflammation and respiratory system mechanics. (C) 2008 Elsevier B.V. All rights reserved.

Elevated left and reduced right orbitomedial prefrontal fractional anisotropy in adults with bipolar disorder revealed by tract-based spatial statistics

Context Diffusion tensor imaging (DTI) studies in adults with bipolar disorder (BD) indicate altered white matter (WM) in the orbitomedial prefrontal cortex (OMPFC), potentially underlying abnormal prefrontal corticolimbic connectivity and mood dysregulatioin in BD. Objective: To use tract-based spatial statistics (TBSS) to examine VVM skeleton (ie, the most compact whole-brain WM) in subjects with BD vs healthy control subjects. Design: Cross-sectional, case-control, whole-brain DTI using TBSS. Setting: University research institute. Participants: Fifty-six individuals, 31 having a DSM-IV diagnosis of BD type 1 (mean age, 35.9 years [age range, 24-52 years]) and 25 controls (mean age, 29.5 years [age range, 19-52 years]). Main Outcome Measures: Fractional anisotropy (FA) longitudinal and radial diffusivities in subjects with BD vs controls (covarying for age) and their relationships with clinical and demographic variables. Results: Subjects with BD vs controls had significantly greater FA (t > 3.0, P <=.05 corrected) in the left uncinate fasciculus (reduced radial diffusivity distally and increased longitudinal diffusivity centrally), left optic radiation (increased longitudinal diffusivity), and right anterothalamic radiation (no significant diffusivity change). Subjects with BD vs controls had significantly reduced FA (t > 3.0, P <=.05 corrected) in the right uncinate fasciculus (greater radial diffusivity). Among subjects with BD, significant negative correlations (P <.01) were found between age and FA in bilateral uncinate fasciculi and in the right anterothalamic radiation, as well as between medication load and FA in the left optic radiation. Decreased FA (P <.01) was observed in the left optic radiation and in the right anterothalamic radiation among subjects with BD taking vs those not taking mood stabilizers, as well as in the left optic radiation among depressed vs remitted subjects with BD. Subjects having BD with vs without lifetime alcohol or other drug abuse had significantly decreased FA in the left uncinate fasciculus. Conclusions: To our knowledge, this is the first study to use TBSS to examine WM in subjects with BD. Subjects with BD vs controls showed greater WM FA in the left OMPFC that diminished with age and with alcohol or other drug abuse, as well as reduced WM FA in the right OMPFC. Mood stabilizers and depressed episode reduced WM FA in left-sided sensory visual processing regions among subjects with BD. Abnormal right vs left asymmetry in FA in OMPFC WM among subjects with BD, likely reflecting increased proportions of left-sided longitudinally aligned and right-sided obliquely aligned myelinated fibers, may represent a biologic mechanism for mood dysregulation in BD.

Studies of RET gene expression and acetylcholinesterase activity in a series of sporadic Hirschsprung`s disease

The purpose is to present the studies of RET gene expression and acetylcholinesterase activity in 23 patients operated for Hirschsprung`s disease (HD). The patients underwent either transanal endorectal pull-through or Duhamell`s procedure. Full-thickness intestinal samples from the three different segments (ganglionic, intermediate and aganglionic) were collected. Each tissue sample was divided in two portions, one for AChE histochemical staining and the other for examination of RET mRNA expression level. All patients had an uneventful postoperative recovery. In all patients, the AChE stainings demonstrated the absence of activity in the ganglionic area, the marked increase of positive fibers in the aganglionic area, and little increase of positive fibers in the intermediate area. In the ganglionic and intermediate areas, all patients (100%) showed significant RET gene expression. In the aganglionic area, 18 patients (78.3%) did not present gene expression and the other five patients (21.7%) presented gene expression that was similar to the ganglionic and intermediate areas. The results reinforce the conclusion that the method of AChE staining is effective for the diagnosis of intestinal aganglionosis and confirm the knowledge that genes beyond RET may be implicated in the genesis of sporadic cases of HD.

Stretch Injuries of Skeletal Muscles: Experimental Study in Rats` Soleus Muscle

The study aimed to verify the physiological injury behavior by stretching the soleus muscle of rats, using a noninvasive experimental model. Twenty-four rats were used and divided into three groups of eight animals: control group (A), group that performed tetanus followed by electrical stimulation and a sudden dorsiflexion of the left paw performed by a device equipped with a mechanism of muscle soleus rapid stretching (B); and a group that only received the tetanus (C). Three days later, the animals were killed, and the soleus muscle was resected and divided into three segments. Morphological changes indicative of muscle damage appeared in all three segments of group B. In a lesser degree, similar changes were also detected in muscles subjected to only tetanus. This model was effective; reproducing an injury similar to what occurs in human sports injuries.

Morphologic and morphometric evaluation of experimental acute crush injuries of the sciatic nerve of rats

In order to qualify and quantify nerve fiber lesion following an acute crush injury, a morphologic and morphometric study was carried out in 25 Wistar rats divided into live groups of five animals each according to the crushing load applied, i.e., 500,1000, 5000, 10 000, and 15 000 g. The injury was produced under general anesthesia on a 5 mm-long intermediate segment of the right sciatic nerve for 10 min using a dead-weight machine. The animals were killed with an excessive dose of anesthetics 72 h later and submitted to perfusion with a fixing solution through the abdominal aorta immediately after death. Both the right and left sciatic nerves were removed and prepared for histologic and morphometric examinations: 5 mu m-thick sections stained with 1% Toluidine blue were examined under a light microscope equipped with a video camera linked to a computer loaded with a graphic program (KS 400). The morphometric studies included measuring total number of fibers, fiber density, fiber diameter, myelin fiber area, axon diameter, axon area and G ratio. The results showed that damage to the nerve fibers began to appear as early as with the 500g load and was similar in all groups despite the load applied, increasing with the 10000 and 15000g loads, although the external supporting tissues and small diameter fibers were preserved. The predominant type of lesion produced was axonotmesis. (c) 2008 Elsevier B.V. All rights reserved.

The Ideal Timing for Experimental Cleft Lip Creation

Cleft lip and palate (CLP) is the most common congenital defect of the face. Many animal models have been utilized to study embryogenesis and pathogenesis of CLP, including the development of secondary anomalies and consequent deformities. However, the ideal gestational age for surgical creation of lip or palate defects in rat models has never been determined. The aim of the present study is to improve the experimental model utilizing rat fetuses, defining the most appropriate timing for creation of the lip defect model. The study was composed of three groups of fetuses undergoing surgical creation of a lip defect at the left side of the superior lip at 17.5, 18.5, and 19.5 days of gestation. Fetuses were harvested at 21.5 days of gestation (term = 22 days) and underwent macroscopic and microscopic analyses. We found that the most appropriate moment for lip defect creation was at 19.5 days, given the presence of lip depression at the site of the defect and asymmetry and retraction associated with interruption of the lip and complete reepithelialization of the borders of the defect.

In pursuit of prognostic factors in children with pilocytic astrocytomas

This study described a 23-year experience in the treatment of children with pilocytic astrocytomas (piloA) with the aim of identifying putative clinical, histopathological, and/or immunohistochemical features that could be related to the outcome of these patients. Clinical data of 31 patients under 18 years of age with piloA were obtained from 1984 to 2006. The mean age at the time of surgery was 7.8 +/- 4.2 years (1 to 17 years), and the mean follow-up was 5.7 +/- 5.4 years (1 to 20 years). The most common site of tumor formation was the cerebellum (17), followed by brainstem (4), optic chiasmatic hypothalamic region (4), cerebral hemisphere (3), cervical spinal cord (2), and optic nerve (1). Gross total resection (GTR) was achieved in 23 (74.1%), mainly in those with tumors located in the cerebellum and cerebral hemispheres (P = 0.02). The global mortality rate was 6.4%. Nine patients were reoperated. Rosenthal fibers, eosinophilic granular bodies, microvascular proliferation, and lymphocytic infiltration were observed in most cases. The mean Ki-67LI was 4.4 +/- 4.5%. In all cases, Gal-3 expression in tumor cells was observed with variable staining pattern. Aside from GTR, no other clinical, histopathological, or immunohistochemical features were found to be related to the prognosis. We postulate that strict follow-up is recommended if piloA is associated with high mitotic activity/Ki67-LI, or if GTR cannot be achieved at surgery. Tumor recurrence or progression of the residual lesion should be strictly observed. In some aspects, childhood piloA remains an enigmatic tumor.