Morphology of human fetal enteric neurons: A comparative study of different segments of the colon

OBJECTIVES

The Enteric Nervous System (ENS) present in the wall of the gut is currently being explored because of its influence on the gut and beyond. In this context, the morphology of developing ENS has not been completely understood in humans due to lack of adequate literature. The aim of the present study was to observe the morphology of the enteric neurons in the human fetal colon and compare the findings in ascending colon a midgut derivative and descending colon a hindgut derivative at various weeks of gestation (WG).

MATERIAL AND METHODS

Tissue samples from 15 aborted fetuses (11 WG to 2 months postnatal) were processed for Cresyl violet, H & E staining, and NADPH Diaphorase histochemistry. The morphometric analysis was done by calculating the neuronal number density and neuronal fractional area. The Student t-test; Mann-Whitney test and Wilcoxon signed-rank test were used to analyze the data.

RESULTS

The muscularis externa with two distinct layers was visible as early as 13 WG and the muscularis mucosae was first observed at 18 WG. The size of the myenteric neurons appeared to be larger with increasing weeks of gestation suggesting a process of neuronal maturation. The neuronal number density and neuronal fractional area seemed to be reduced with advancing fetal age. There was no marked difference between the ascending and sigmoid colon. At 23 and 26 WG, a mature pattern of nitrergic innervation was observed.

CONCLUSION

This study is done on human fetal tissue samples unlike previous studies on animal samples to comprehend the morphology of developing ENS. It will aid in understanding the effect of ENS on various neurological disorders.

Neuromuscular variations in the gluteal region - Embryological basis and clinical significance

ABSTRACT

Piriformis, is a key muscle in the gluteal region. Under its lower border sciatic nerve and inferior gluteal nerves exit. During routine educational dissection of the lower limb, bilateral gluteal regions in fifteen cadavers (30 gluteal regions) focusing on the variations of inferior gluteal nerve and sciatic nerve with respect to piriformis muscle were observed in the department of anatomy, All India Institute of Medical Sciences, New Delhi, India. In one of the left sided specimens, inferior gluteal nerve had an abnormal course, piercing superior belly of piriformis muscle instead of emerging through the lower border of it along with variation of the sciatic nerve. The common peroneal component of the sciatic nerve was coming out between the two anomalous tendinous slips of the piriformis muscle, whereas the tibial component, emerged along lower border of the piriformis muscle bilaterally in the same cadaver. In the remaining cadavers, there were no variations of the inferior gluteal nerve with respect to the piriformis muscle. But in another cadaver, there was a similar variation of the sciatic nerve bilaterally. Inferior gluteal and sciatic nerves, when compressed by muscle belly or tendinous slips of the piriformis muscle, may cause lurching gait and sciatica respectively. Knowledge of the different variations of these peripheral nerves with respect to the piriformis muscle is important to clinicians and surgeons for the accurate diagnosis and intervention.

Morphology of enteric glia in colorectal carcinoma: A comparative study of tumor site and its proximal normal margin

OBJECTIVE

Colorectal carcinoma (CRC) is the third most common cancer in the world and fifth most common cancer in India. To understand the extent of perineural invasion (PNI) in CRC it is essential to study the morphology of enteric glial cells (EGCs). The aim of the study was to analyze the numerical density of EGCs and area of myenteric ganglia (MG) in the colonic tissue samples collected from CRC patients.

MATERIAL AND METHODS

Fifteen intraoperative tissue specimens were collected from the tumor site and 2cm proximal to the upper extent of tumor. The samples were divided into four groups: group 1 (n=15): proximal tumor free colonic tissue; group 2 (n=3): well-differentiated; group 3 (n=8): moderately differentiated; group 4 (n=4): poorly differentiated adenocarcinoma. After processing the tissues were subjected to hematoxylin and eosin staining. The anti-S100β and anti-GFAP antibodies were used to observe the EGCs.

RESULTS

In the H&E stained sections the number of myenteric ganglia appeared to be decreasing with increasing grade of adenocarcinoma. Immunostaining showed significant decreasing pattern in the numerical density of EGCs per myenteric ganglion and mean area of myenteric ganglia in relation to the thickness of circular muscle, corresponding to the increasing grades of adenocarcinoma. The morphology of the EGCs remained unaltered in the colonic tissue adjacent to the tumor site.

CONCLUSION

Significant loss of EGCs and neurodegeneration corresponded with the grade of tumor emphasizing on its prognostic value. The PNI was not seen in the clear margin proximal to the tumor site.

Pharmacological treatments for acute respiratory distress syndrome: systematic review

BACKGROUND

Our objective was to systematically review the effect of pharmacological therapies on mortality in patients with acute respiratory distress syndrome (ARDS), focusing on randomized controlled trials (RCTs) published since a previous review in 2004.

METHODS

We updated previous searches and searched OVID versions of MEDLINE, EMBASE and CENTRAL (to January 2013) and proceedings from conferences and bibliographies of included studies. We included RCTs of pharmacologic therapies compared with placebo or no therapy for adult patients with ARDS, using authors' definitions, which reported on mortality (≤ 3 months after randomization). We excluded subgroups of patients with ARDS reported in RCTs enrolling other populations and RCTs of therapies to prevent ARDS, nutritional or fluid interventions, inhaled nitric oxide, therapies coupled to a mechanical ventilation strategy, or oxygen. Two reviewers independently screened citations, selected articles for inclusion, and abstracted clinical and methodological data from included studies with disagreements resolved by a third reviewer. Mortality data were pooled using random-effects models.

RESULTS

From 13461 citations, 58 trials (6635 patients) of 21 classes of medications met selection criteria; 26 trials (3880 patients) were published after 2003. Meta-analyses showed reduced 28-day mortality with a 48-hour infusion of cis-atracurium in early ARDS (relative risk 0.66, 95% confidence interval 0.50 to 0.87; 431 patients, 138 deaths). There was no effect on mortality with granulocyte-macrophage colony stimulating factor, late low-dose methylprednisolone, neutrophil elastase inhibitors, intravenous salbutamol, surfactant, or N-acetylcysteine; each meta-analysis included ≥ 1 trial published after 2003. Seven single trials of other treatments published after 2003 showed no effect. Meta-analysis of older trials of prostaglandin E1 also showed no effect.

CONCLUSION

Effective pharmacotherapy for ARDS remains extremely limited. Cis-atracurium is a promising treatment for early moderate-severe ARDS (using Berlin definition nomenclature) and merits further investigation in a large RCT.

Transforming growth factor-β enhances invasion and metastasis in Ras-transfected human malignant epidermal keratinocytes

Transforming growth factor-β (TGF-β) is known to act as a tumour suppressor early in carcinogenesis, but then switches to a pro-metastatic factor in some late stage cancers. However, the actions of TGF-β are context dependent, and it is currently unclear how TGF-β influences the progression of human squamous cell carcinoma (SCC). This study examined the effect of overexpression of TGF-β1 or TGF-β2 in Ras-transfected human malignant epidermal keratinocytes that represent the early stages of human SCC. In vitro, the proliferation of cells overexpressing TGF-β1 or TGF-β2 was inhibited by exogenous TGF-β1; cells overexpressing TGF-β1 also grew more slowly than controls, but the growth rate of TGF-β2 overexpressing cells was unaltered. However, cells that overexpressed either TGF-β1 or TGF-β2 were markedly more invasive than controls in an organotypic model of SCC. The proliferation of the invading TGF-β1 overexpressing cells in the organotypic assays was higher than controls. Similarly, tumours formed by the TGF-β1 overexpressing cells following transplantation to athymic mice were larger than tumours formed by control cells and proliferated at a higher rate. Our results demonstrate that elevated expression of either TGF-β1 or TGF-β2 in cells that represent the early stages in the development of human SCC results in a more aggressive phenotype.

Abstract 1490: Role for Id1 in oral cancer progression

This investigation determined whether Id1 expression in lesions or lesion associated vessels increases during the progression of oral cancer. Oral cancer incidence is increasing and there has been no change in the five year survival rate for the disease in several decades. Biomarkers to identify early lesions that are likely to progress to cancer and targets for therapy of later stage disease are urgently needed. This work extends a previous study linking Id1 (inhibitor of DNA binding/differentiation) with oral cancer by examining Id1 expression during oral cancer progression and its association with angiogenesis. If we can obtain evidence that expression of Id1 is elevated in dysplasias or their associated vessels and correlates with those dysplasias that progress to cancer, Id1 would be a potential biomarker for the disease and possibly a target for therapeutic intervention.

Expression of Id1 and the endothelial marker CD31 were determined by immunohistochemistry in serial sections of human normal oral mucosa, dysplastic lesions, squamous cell carcinomas (SCC) that have not metastasised to date and those that have metastasised to lymph nodes. The Id1 antibody used has been shown to be highly specific for the protein in contrast to other Id1 antibodies that have been used in previous studies which have recently been shown to detect additional non-specific proteins. The proportion of vessels positive for Id1 was determined by Chalkley counting, a method suggested to be used as a standard in an international consensus on quantification of angiogenesis. In all sections, 5 areas with a high density of vessels were selected and Chalkley counts performed to determine the number of vessels as detected by CD31 expression and the proportion of those that were positive for Id1.

Our results show that there is a marked increase in Id1 intensity and the proportion of cells that are positive for Id1 in lesions (dysplasia, SCC that that had metastasised and those that to date have not) as compared to normal oral mucosa. More samples are needed, however, to confirm whether Id1 could be used as a biomarker for oral cancer. In tumour vasculature, both the intensity of Id1 expression and the percent of endothelial cells positive for the protein correlated with tumour aggressiveness, with the highest expression levels evident in the SCCs that have metastasised to lymph nodes. These data suggest that Id1 might be a good target for therapy of SCC and that Id1 may play a role in neoangiogenesis in oral cancer. In conclusion our data demonstrate that Id1 expression could be a biomarker for oral SCC, correlates with tumour aggressiveness and may play a role in neoangiogenesis in the disease. As the main site to which oral SCCs metastasise are the lymph nodes, we aim to extend this work to determine whether Id1 may be responsible for neolymphangiogenesis in this disease.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1490. doi:10.1158/1538-7445.AM2011-1490

TGF-β inhibits metastasis in late stage human squamous cell carcinoma of the skin by a mechanism that does not involve Id1

It is now generally accepted that TGF-β acts as a pro-metastatic factor in advanced human breast cancer. However, it is well documented, that TGF-β is context dependent, and whether the TGF-β pathway switches to promote metastasis during the progression of squamous cell carcinoma (SCC) is unknown. This study examined the role of TGF-β signalling in SCC using a series of genetically related keratinocyte cell lines representing later stages of the disease, stably transduced with a dominant negative TβRII cDNA (dnTβRII). We demonstrated that clones expressing dnTβRII lost their growth inhibitory response to TGF-βin vitro, while ligand expression remained unchanged. Following transplantation of transduced cells to athymic mice in vivo, we showed that attenuation of the TGF-β signal resulted in a loss of differentiation and increased metastasis. In human tissue samples loss of TGF-β signal transduction as measured by pSmad2 activity also correlated with a loss of differentiation. Id1, previously shown to be down regulated by TGF-β, an inhibitor of differentiation and associated with metastasis, was weakly expressed in focal areas of a small number of human tumours but expression did not correlate with low levels of pSmad2. Our data demonstrate that TGF-β does not switch to promote metastasis in late stage human SCC of the skin and that inhibition of TGF-β signalling results in a loss of differentiation and increased metastasis in the later stages of this disease.

GeMInA, Genomic Metadata for Infectious Agents, a geospatial surveillance pathogen database

The Gemina system (http://gemina.igs.umaryland.edu) identifies, standardizes and integrates the outbreak metadata for the breadth of NIAID category A-C viral and bacterial pathogens, thereby providing an investigative and surveillance tool describing the Who [Host], What [Disease, Symptom], When [Date], Where [Location] and How [Pathogen, Environmental Source, Reservoir, Transmission Method] for each pathogen. The Gemina database will provide a greater understanding of the interactions of viral and bacterial pathogens with their hosts and infectious diseases through in-depth literature text-mining, integrated outbreak metadata, outbreak surveillance tools, extensive ontology development, metadata curation and representative genomic sequence identification and standards development. The Gemina web interface provides metadata selection and retrieval of a pathogen's; Infection Systems (Pathogen, Host, Disease, Transmission Method and Anatomy) and Incidents (Location and Date) along with a hosts Age and Gender. The Gemina system provides an integrated investigative and geospatial surveillance system connecting pathogens, pathogen products and disease anchored on the taxonomic ID of the pathogen and host to identify the breadth of hosts and diseases known for these pathogens, to identify the extent of outbreak locations, and to identify unique genomic regions with the DNA Signature Insignia Detection Tool.

Cell death induced by N-(4-hydroxyphenyl)retinamide in human epidermal keratinocytes is modulated by TGF-beta and diminishes during the progression of squamous cell carcinoma

It has been demonstrated that the chemopreventive agent N-(4-hydroxyphenyl)retinamide (4-HPR) induces apoptotic cell death, but recent data has suggested that late stage/recurrent tumours lose their response to 4-HPR-induced cell death by mechanisms that are unknown. Our study investigated the ability of 4-HPR to induce cell death in keratinocyte cell lines that represent different stages of carcinogenesis and the role of TGF-beta signalling in the induction of cell death by 4-HPR. We show that treatment of the immortalised keratinocyte cell line HaCaT with 10(-5) M 4-HPR induced cell death by apoptosis and caused an accumulation of cells in the G0/G1 phase of the cell cycle. Using a genetically related series of human skin keratinocytes derived from HaCaT that reflect tumour progression and metastasis in vivo, we demonstrate that 4-HPR-induced cell death and apoptosis is attenuated in the more aggressive tumour cell lines but that a reduced level of response is retained. Response to TGF-beta-induced growth inhibition was also reduced in the more aggressive cell lines. Treatment of HaCaT cells with 4-HPR induced TGF-beta2 expression and an increase in the amount of active TGF-beta in the culture medium. The inhibition of TGF-beta signalling attenuated 4-HPR-induced apoptosis and both TGF-beta1 and TGF-beta2 potentiated 4-HPR-induced apoptosis and enhanced 4-HPR-induced growth inhibition. Our results demonstrate that loss of response to 4-HPR correlates with a loss of response to the growth inhibitory effects of TGF-beta and that adjuvant therapies that upregulate TGF-beta may enhance the chemopreventive effects of 4-HPR.