Femoral tripod arteries: Surgical anatomic variants.

AIM: To describe the surgical anatomy of the femoral tripod arteries and their anatomical variants. MATERIALS AND METHODS: Patients who underwent vascular surgery by external arciform approach of the Scarpa between May 2022 and July 2022 were selected. The surgical anatomy was assessed by direct observation. The origin and the course of major branches of the femoral artery (FA) were studied. Diameters and the distance of the origin of the femoral profunda artery (FPA) from the midpoint of the inguinal ligament was measured in millimeters and recorded. The observed anatomical variations were photographed and compared to those in the literature. RESULTS: A total of 40 patients (34 men, 85%) were included. The median diameter of the common femoral artery (CFA) was 9mm (IQR: 7-12mm). The Modal bifurcation was noted in 95% of cases. The collateral branches of the CFA were found to be distributed as follows: the superficial circumflex iliac artery (SCIA) in 34 cases (85%), the superficial epigastric artery (SEA) in 22 cases (55%), the deep external pudic artery in 16 cases (40%), and the superficial external pudic artery in 18 cases (45%). The median diameter of the FPA was 5mm (IQR: 4-6mm). The FPA originated from the posterolateral side of the CFA in 90% of cases, from the posterior side in 5% of cases and from the medial side in 5% of cases. The median diameter of the SFA was 6mm (IQR: 4-9mm). CONCLUSION: The anatomic variants of the femoral tripod arteries are extremely frequent. Therefore, it is important to recognize the anatomy in order to avoid possible diagnostic errors and to minimize the risk of per and post procedural complications.

Effect of soil type and temperature on survival of Salmonella enterica in poultry manure-amended soils.

The effects of soil type and temperature on the survival of a cocktail of five Salmonella enterica serotypes (Enteritidis, Infantis, Montevideo, Typhimurium and Zanzibar) in manure-amended soils under controlled laboratory conditions was assessed. Containers of clay loam or sandy soil, unaltered or amended with 2% (w/w) poultry manure, were inoculated with S. enterica (~5 log10 CFU per gram) and held at 5, 21 or 37°C for 6 weeks. Statistical analysis of the persistence of S. enterica identified a significant three-way interaction between soil type, manure amendment and temperature. Clay loam soils and lower temperatures tended to support S. enterica persistence over 6 weeks with only 1- and 2-log reductions respectively. In contrast, sand and higher temperatures resulted in a 4-log and either 3- to 4-log reductions respectively. Manure amendment had an overarching effect of reducing die-off of S. enterica in comparison with unamended soils. This study highlights that a large component of variation of the rate of S. enterica reduction in soils may be attributed to combinations of environmental factors, in particular, soil type and temperature. It further underscores the importance of risk management strategies and industry guidelines based on local data and that reflect the diversity of prevailing horticultural production environments. SIGNIFICANCE AND IMPACT OF THE STUDY: The persistence of Salmonella enterica in soil environments was shown to be significantly influenced by a range of individual and interacting environmental effects, including temperature, soil type and amendment addition. This indicates that current horticultural food safety management systems which employ a uniform prescribed exclusion period between application of manure and time of harvest may be unfit for purpose under certain conditions by either underestimating or overestimating pathogen die-off. These findings support exclusion periods that account for a range of environmental factors including temperature, soil type and growing region that may be more appropriate to manage microbiological risks associated with soil which has been amended with manure.

[Distribution of corneal thickness in the Tunisian population: Study by anterior segment optical coherence tomography]. / Distribution de l'épaisseur cornéenne centrale dans la population tunisienne : étude par tomographie en cohérence optique du segment antérieur.

GOALS: To describe the distribution of the central corneal thickness (CCT) in the Tunisian population. METHODS: A prospective descriptive study was performed in 201 right eyes of 201 randomly selected healthy Tunisian subjects without glaucoma. We measured the spherical error by autorefraction, the axial length using A-scan ultrasound biometry and the central corneal thickness using anterior segment optical coherence tomography (DRI TRITON OCT). RESULTS: We examined 201 eyes. The mean age was 47±13.5 years (18 to 77 years). The M/F sex ratio was at 0.46 (137 women and 64 men). The mean CCT was 508,1µm (standard deviation 31,5µm) and ranged from 440 to 600µm. In our population 43.8% had a CCT less than 500µm, and 89.1% had a CCT less than 550µm. No statistically significant correlation was observed between CCT and age, sex, spherical error or axial length. CONCLUSION: Central corneal thickness in the Caucasian Tunisian population is less than CCT in the European and Asian populations. CCT is independent of age, sex, spherical error or axial length. These results must be confirmed by larger multicentric studies.

[Anatomo-functional study in branch retinal vein occlusion using Swept Source Optical Coherence Tomography Angiography]. / Occlusion de branche veineuse rétinienne : analyse anatomo-fonctionnelle par Swept Source Optical Coherence Tomography Angiographie (OCT-Angiographie).

INTRODUCTION: The purpose of our study was to describe the microvascular abnormalities on OCT-angiography in eyes with branch retinal vein occlusion (BRVO), to measure the surface of the foveal avascular zone (FAZ) and the capillary density, and to establish anatomic-functional correlations. METHODS: We conducted an observational prospective study in the ophthalmology department of Habib Thameur Hospital in Tunis, which included 17 eyes of patients with unilateral BRVO. We studied the microvascular abnormalities and areas of capillary non-perfusion in the deep and superficial capillary plexuses (DCP, SCP). The area of the FAZ was measured in the SCP and correlated to visual acuity. The foveal and parafoveal capillary density was measured with flow quantification software. RESULTS: The mean patient age was 57.94 ±18.04 years. Male:female ratio was approximately 1. Fourteen eyes (82.4%) showed cystoid macular edema which was significantly correlated to poor visual acuity (P=0.02). Vascular congestion was present in 12 eyes (70.60%) in the DCP and 8 eyes (47.1%) in the SCP. Intraretinal loops were found in 5 eyes (29.4%) in the DCP and 8 eyes (47.1%) in the SCP. Thirteen eyes (76.5%) exhibited vascular tortuosity in the DCP, and 14 eyes (82.4%) in the SCP. Areas of capillary non-perfusion were observed in 12 eyes (70.60%). The mean area of the FAZ was 617.53±525.75µ in eyes with BRVO. Enlargement of the FAZ was correlated to visual loss (P=0.01). Mean foveal capillary density was 15.49% (±5.18%), and mean peripheral capillary density was 44% (±4.75%). There was no correlation between vascular density and visual acuity in our series. CONCLUSIONS: OCT-angiography is part of the current diagnostic workup for RVO. It has a relevant role in establishing a prognosis by studying the area of the FAZ and the capillary density.

[Bilateral pseudotumoral proptosis as presenting sign of orbital hyper-IgG4-related disease]. / Exophtalmie bilatérale pseudo-tumorale révélant un syndrome hyper-IgG4 orbitaire.

INTRODUCTION: Hyper-IgG4 syndrome is a rare cause of bilateral proptosis. It must always be considered after ruling out orbital lymphoma. CASE REPORT: We report a case of progressive bilateral proptosis for 4 years in a 34-year-old man. Orbital MRI showed an infiltrative process extending to the orbital fat, extraocular muscles and lacrimal glands. Lacrimal gland biopsy with immunohistochemical study showed a lymphoplasmocytic infiltrate rich in IgG4 and fibrosis. The diagnosis of orbital hyper-IgG4 syndrome was suggested. The patient responded well to systemic steroid treatment. DISCUSSION: Orbital hyper-IgG4 syndrome manifests most often as pseudo-tumoral bilateral proptosis. Elevated IgG4 levels are neither sensitive nor specific. Biopsy with immunohistochemical study is the key to diagnosis. Systemic steroid treatment is the gold standard, but recurrences may occur.

[Avian infectious bronchitis disease in Tunisia: seroprevalence, pathogenicity and compatibility studies of vaccine-field isolates]. / La bronchite infectieuse aviaire en Tunisie: séroprévalence, pathogénicité et étude de compatibilité vaccin-isolats.

A sero-epidemiological study was carried out on 5660 sera collected, between 2006 and 2008, from different flocks in different regions of the country. The ELISA results showed low levels of antibodies indicating vaccination failures. 45 to 69% of the flocks showed positive levels of antibodies and only 5 to 15% of these were protected. The pathogenicity studies of the Tunisian field isolates TN20/00 and TN335/01 demonstrated high clinical and lesion scores indicating the pathogenic effect of the two isolates. The challenge experiments conducted to evaluate the cross-protection between the H120 vaccine and the field isolates showed low protection rate, especially against the TN20/00 virus. The overall results allowed the determination of the pathogenic nature of the field isolates and a vaccination program based on the use of the only Massachusetts H120 strain did not reduce tracheal and kidney lesions. To better control the disease, adapting the vaccination program by using vaccine allowing better protection against variant strains, is recommended.

In vivo analysis of the model tyrosine aminotransferase gene reveals multiple sequential steps in glucocorticoid receptor action.

We are studying the mechanisms of transcriptional activation by nuclear receptors and we focus our studies on the glucocorticoid regulation of the model tyrosine aminotransferase gene. Rather than using in vitro biochemical approaches, we determine the actual events occurring in the cells. Our experimental approaches include genomic footprinting, chromatin immunoprecipitation, in situ hybridization and transgenic mice. Our results show that the glucocorticoid receptor uses a dynamic multistep mechanism to recruit successively accessory DNA binding proteins that assist in the activation process. Chromatin is first remodelled, DNA is then demethylated, and the synthesis of an accessory factor is induced. Efficient transcription induction is finally achieved upon the formation of a 'stable' multiprotein complex interacting with the regulatory element. We discuss: the relative contribution of histone acetyltransferases and ATP-dependent remodelling machines to the chromatin remodelling event; the nature of the remodelled state; the contribution of regulated DNA demethylation to gene memory during development; the mechanisms of regulated DNA demethylation; the dynamics of protein recruitment at regulatory elements; the control of the frequency of transcription pulses and the control levels of the cell-type specificity of the glucocorticoid response.

A mechanistic model for the development and maintenance of portocentral gradients in gene expression in the liver.

In the liver, genes are expressed along a portocentral gradient. Based on their adaptive behavior, a gradient versus compartment type, and a dynamic versus stable type of gradient have been recognized. To understand at least in principle the development and maintenance of these gradients in gene expression in relation to the limited number of signal gradients, we propose a simple and testable model. The model uses portocentral gradients of signal molecules as input, while the output depends on two gene-specific variables, viz., the affinity of the gene for its regulatory factors and the degree of cooperativity that determines the response in the signal-transduction pathways. As a preliminary validity test for its performance, the model was tested on control and hormonally induced expression patterns of phosphoenolpyruvate carboxykinase (PCK), carbamoylphosphate synthetase I (CPS), and glutamine synthetase (GS). Affinity was found to determine the overall steepness of the gradient, whereas cooperativity causes these gradients to steepen locally, as is necessary for a compartment-like expression pattern. Interaction between two or more different signal gradients is necessary to ensure a stable expression pattern under different conditions. The diversity in sequence and arrangement of related DNA-response elements of genes appears to account for the gene-specific shape of the portocentral gradients in expression. The feasibility of testing the function of hepatocyte-specific DNA-response units in vivo is demonstrated by integrating such units into a ubiquitously active promoter/enhancer and analyzing the pattern of expression of these constructs in transgenic mice.

Glucocorticoids are insufficient for neonatal gene induction in the liver.

Glucocorticoids and their receptor (GR) play a key role in perinatal gene induction. In the liver, the GR is essential for the neonatal induction of a number of genes, including that coding for tyrosine aminotransferase (TAT). To assess the function of the GR in the perinatal period, we have compared the activity of two types of glucocorticoid responsive elements in transgenic mice; one is the Tat gene glucocorticoid-responsive unit (GRU), an assembly of numerous binding sites for transcription factors, including the GR; the other is a simple dimer of high-affinity GR binding sites (GREs). Both elements confer strong glucocorticoid response in the adult liver. However, only the Tat GRUs are able to promote neonatal induction; the GRE dimer is unresponsive. Because this dimer is responsive to glucocorticoid administration in the neonate, the absence of neonatal induction is not due to the inactivity of the GR at this stage. At birth, the neonate has to withstand a brief period of starvation and hypoglycemia, a nutritional and hormonal situation that resembles fasting in the adult. In transgenic mice, the responses at birth and after fasting in the adult are similar: the Tat GRUs but not the dimeric GREs are activated. Our results show that, in rodents, glucocorticoids are not sufficient for neonatal gene induction in the liver and support the conclusion that the hypoglycemia at birth is the main trigger for expression.

Tissue specificity of a glucocorticoid-dependent enhancer in transgenic mice.

The glucocorticoid-responsive units (GRUs) of the rat tyrosine aminotransferase were associated with the regulatory sequences of a cellular gene expressed ubiquitously--that coding for the largest subunit of RNA polymerase II. In transient expression assays, glucocorticoid responsiveness of the hybrid regulatory regions depends on the spatial relationship and number of regulatory elements. Two parameters affect the ratio of induction by glucocorticoids: the basal level of the hybrid promoter that is affected by the RNA polymerase II regulatory sequences and the glucocorticoid-induced level that depends on the distance between the GRUs and the TATA box. A fully active glucocorticoid-responsive hybrid gene was used to generate transgenic mice. Results show that a composite regulatory pattern is obtained: ubiquitous basal expression characteristic of the RNA polymerase II gene and liver-specific glucocorticoid activation characteristic of the tyrosine aminotransferase GRUs. This result demonstrates that the activity of the tyrosine aminotransferase GRUs is cell-type-specific not only in cultured cells but also in the whole animal.