Cervical spondylolysis: a case report

Cervical spondylolysis is defined as a corticated cleft between the superior and inferior articular facets of the articular pillar, the cervical equivalent of the pars interarticularis in the lumbar spine. Of primary importance is its recognition to avoid confusion with more clinically significant abnormalities such as fracture or dislocation. This case report describes bilateral spondylolysis and associated dysplasia of C5 in a 31-year-old female. We describe the radiographic presentation of this anomaly, stressing the importance of computed tomography for correct diagnosis. A review of the literature on this interesting abnormality and a complete differential diagnosis are presented.     

Loss of heterozygosity at the BRCA1 locus in Tunisian women with sporadic breast cancer

Breast cancer in Tunisia is characterized by a much higher incidence of aggressiveness compared with Western countries. The pattern of allelic loss at the BRCA1 locus in Tunisian women with breast carcinoma has not been studied. Therefore, the aim of this present preliminary study was mainly focused on loss of heterozygosity (LOH) analysis of the BRCA1 gene to determine if this tumor suppressor gene is involved in sporadic breast carcinoma among Tunisian women. We investigate allelic losses by analyzing three microsatellite markers in the BRCA1 region, in a panel of 21 human breast tumors. D17S1322 marker had the highest frequency of LOH (59%), followed by the D17S1323 (35%), and EDH-17B (20%). Collectively out of 21 informative cases 13 (62%) showed LOH at at least one BRCA1 locus. This data provides evidence that allelic loss at BRCA1 is a frequent event in sporadic breast tumorigenesis among Tunisian women, and suggests that the BRCA1 gene might play an important role as a tumor suppressor gene.     

Tumeur myofibroblastique inflammatoire de la vessie

Myofibroblastic inflammatory tumor is considered as an intermediate neoplasm according to the WHO classification. It can occur in different organs: lung, pancreas, mesentery and uterus. The localization in the bladder is unusual. We report a case of a 38-year-old patient who presented with hematuria. Echography showed a 3 cm tissular structure of the bladder. Histological analysis and immunohistochemistry concluded to the diagnosis of myofibroblastic tumor of the bladder. The present work will give a general view of the myofibroblastic tumor, and will review its differential diagnosis.     

First case of childhood Takayasu arteritis with renal artery aneurysms

Takayasu arteritis is a large vessel systemic granulomatous vasculitis characterized by stenosis or obliteration of large and medium sized arteries. It commonly involves elastic arteries such as the aorta and its main branches. Renal artery involvement is rare and has not been reported in a child. We report a 12-year-old boy with Takayasu arteritis who developed severe hypertension, proteinuria, microscopic hematuria and renal dysfunction. Conventional angiography demonstrated aneurysms of both renal arteries and multiple microaneurysms of the superior mesenteric artery. This case report illustrates that the children with Takayasu arteritis can develop renal involvement resulting in hematuria, proteinuria and even renal failure.     

β-endorphin degradation and the individual reactivity to traumatic stress

Reactivity to traumatic stress varies between individuals and only a minority of those exposed to trauma develops stress-induced psychopathologies. Currently extensive effort is made to unravel the specific mechanisms predisposing to vulnerability vs. resilience to stress. We investigated in rats the role of β-endorphin metabolism in vulnerability to acute traumatic stress. Responders (showing extreme anxiety; n=7) and resilient non-responders (not differing from the non-stressed individuals; n=8) to traumatic foot-shock stress were compared for their blood levels of stress hormones as well as brain levels and activity of two opioid-degrading enzymes. β-endorphin is a substrate to insulin degrading enzyme, which also degrades insulin. Therefore, the effects of insulin application on behavioral and hormonal responses and on β-endorphin degradation were tested. Pre- and post-stress levels of serum corticosterone, and post-stress plasma β-endorphin concentration differentiated between the responders and the non-responders. In brain, responders showed enhanced degradation rates of β-endorphin, assessed by Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS), in hippocampal and amygdalar slices as compared to non-responders. Application of insulin to the amygdala, prior to exposure to traumatic stress, reduced post-stress anxiety and serum corticosterone levels only in the responders. In parallel, amygdalar β-endorphin degradation rate was also reduced by insulin. These results suggest that slowing down β-endorphin degradation rate may constitute an integral part of the normal stress-response, upon a failure of which an extreme anxiety develops. Modulation of opioid degradation may thus present a potential novel target for interference with extreme anxiety.     

Immunohistochemical expression pattern of MMR protein can specifically identify patients with colorectal cancer microsatellite instability

The microsatellite instability (MSI) pathway is found in most cases of hereditary nonpolyposis colorectal cancer (HNPCC) and in 12 % of sporadic colorectal cancer (CRC). It involves inactivation of deoxyribonucleic acid mismatch repair (MMR) genes MLH1, MSH2, PMS2, and MSH6. MMR germline mutation detections are an important supplement to HNPCC clinical diagnosis. It enables at-risk and mutation-positive relatives to be informed about their cancer risks and to benefit from intensive surveillance programs that have been proven to reduce the incidence of CRC. In this study, we analyzed for the first time in Tunisia the potential value of immunohistochemical assessment of MMR protein to identify microsatellite instability in CRC. We evaluate by immunohistochemistry MMR protein expression loss in tumoral tissue compared to positive expression in normal mucosa. Immunohistochemistry revealed loss of expression for MLH1, MSH2, MSH6, and PMS2 in 15, 21, 13, and 15 % of cases, respectively. Here, we report a more elevated frequency of MSI compared to data of the literature. In fact, by immunohistochemistry, 70 % of cases were shown to be MSS phenotype, whereas 30 % of cases, in our set, were instable. Moreover, according to molecular investigation, 71 % of cases were instable (MSI-H) and remaining cases were stable (29 %). Thus, we found a perfect association between MMR immunohistochemical analyses and MSI molecular investigation. Immunohistochemical analysis of MMR gene product expression may allow one to specifically identify MSI phenotype of patients with colorectal carcinomas.     

Improving the Validity of Peripheral Venous Blood Gas Analysis as an Estimate of Arterial Blood Gas by Correcting the Venous Values with SvO2

Background

Peripheral venous blood gas (pVBG) analysis in replacement of arterial blood gas (ABG) is limited by the unpredictable differences between arterial and venous values, especially for PCO₂ and pH (ΔPCO₂ and ΔpH).

Objectives

We hypothesized that, using the theoretical relationship linking SvO₂ and blood flow, we could diminish the effect of local circulatory conditions on ΔPCO₂ and ΔpH and thereby increase pVBG validity.

Methods

This was a prospective cross-sectional study performed in emergency patients requiring a blood gas analysis in which ABG and pVBG were performed simultaneously. The data of 50 randomly selected patients (model group) were used for developing two equations to correct PvCO₂ and pHv according to the peripheral SvO₂ (SpvO₂) level. The formulas derived were PvCO_2cor = PvCO₂ − 0.30 × (75 − SpvO₂), and pHv_cor = pHv + 0.001 × (75 − SpvO₂). The validity of the corrected values was then tested on the remaining population (validation group).

Results

There were 281 patients included in the study, mainly for dyspnea. ΔPCO₂ and ΔpH were strongly correlated with SpvO₂ (r² = 0.62 and r² = 0.53, respectively, p < 0.001). Using the data of the model group, we developed equations that we applied on the validation group. We found that the corrected values were more valid than the raw values for detecting a PaCO₂ > 45 mm Hg (AUC ROC = 0.96 ± 0.01 vs. 0.89 ± 0.02, p < 0.001), a PaCO₂ < 35 mm Hg (AUC = 0.95 ± 0.02 vs. 0.84 ± 0.03, p < 0.001), a pHa < 7.35 (AUC = 0.97 ± 0.01 vs. 0.95 ± 0.02, p < 0.05), or a pHa > 7.45 (AUC = 0.91 ± 0.02 vs. 0.81 ± 0.04, p < 0.001).

Conclusions

The variability of ΔPCO₂ and ΔpH is significantly lowered when the venous values are corrected according to the SpvO₂ value, and pVBG is therefore more accurate and valid for detecting an arterial abnormality.     

Modulation of type 1 diabetes susceptibility by tumor necrosis factor alpha -308 G/A and lymphotoxin alpha +249 A/G haplotypes and lack of linkage disequilibrium with predisposing DQB1-DRB1 haplotypes in Bahraini patients

Tumor necrosis factor alpha (TNF-α) −308 G/A and lymphotoxin alpha (LTα) +249 A/G single-nucleotide polymorphisms were investigated in 228 type 1 diabetes mellitus (T1DM) patients and 240 controls. Only LTα +249G allele and +249G/+249G genotype frequencies were higher among patients, and no linkage disequilibrium was found between TNF-α/LTα alleles and susceptible/protective DRB1-DQB1 haplotypes. TNF-α/LTα T1DM-susceptible (−308G/+249G) and protective (−308G/+249A) haplotypes were identified.     

Thyroglobulin polymorphisms in Tunisian patients with autoimmune thyroid diseases (AITD)

The thyroglobulin (Tg) gene was reported to be linked and/or associated to autoimmune thyroid diseases (AITD) development in European Caucasian populations. Here, we attempt to replicate this finding and to evaluate the contribution of the Tg gene in the genetic susceptibility of AITD in the Tunisian population. We examined the genomic region (11.5cM) containing the Tg gene by genotyping seven microsatellite markers and four SNPs located respectively at exon 10 (Ser715Ala), exon 12 (Met1009Val), exon 21 (Ala1483Ala) and exon 33 (Arg1980Trp) in 15 Tunisian multiplex families affected with AITD including Graves' disease (GD) and Hashimoto's thyroiditis (HT) (members: 87; patients: 27 GD and 16 HT). A case-control study was performed by genotyping the Tgms2 intragenic microsatellite marker (intron 27) and four intragenic SNPs on 108 unrelated patients affected with GD and 169 normal controls. Analysis of family data did not show linkage of the thyroglobulin gene with AITD nor did analysis of case-control data show association of Tgms2 or SNPs with GD. In contrast to the European Caucasian population, we failed to detect any contribution of Tg gene in the genetic component of Tunisian AITD.