Wednesday, 21 February 2018

Risk Factors of Surgical Recurrence after Resection for Crohn's Disease


The surgery is required in more than 80% of patients with Crohn’s disease. Crohn’s disease is associated with high rates of postoperative recurrence. The aim of the study was to identify, the risk factors of postoperative ‘surgical recurrence’ after the first resection for Crohn’s disease.

We report a retrospective study from January 1998 to September 2010 that studied 226 patients originated only from Tunisia (in North Africa), operated on for MC. We had been interested to the risk factor of surgical recurrence of Crohn’s disease.

Mean age was 33 years. The average time between the onset of the disease and the surgical procedure was 31 months. The diagnosis of CD was established preoperatively in 213 patients (94%). The diagnosis was made intraoperatively because of an acute complication in 5 cases (2.2%) and postoperatively in 8 cases (3.5%). The most common location was the ileocecal junction in 184 cases (81.4%). The most common type of lesion was the mixed form (stricture and fistula) in 123 cases (54.4%). Operative mortality was 0.04% (n=1). Specific morbidity was 8.4% (n=19). In long term, a surgical recurrence was noted in 18 patients (8%). In multivariate analysis, independent risk factors for recurrence were: smoking (p=0.012, ORs=3.57) and post-operative medical treatment (p=0.05, ORs=2.6).

Our series is unique for a lower rate of the postoperative recurrence (8%). The two risk factors of recurrence are smoking and the necessity of postoperative medical prophylaxis.

Pleomorphic Sarcoma of the Head and Neck Region


Pleomorphic Sarcoma or Malignant Fibrous Histiocytoma is commonest soft tissue sarcoma but is rare in Head and neck. Commonest site in Head and neck being Nasal cavity and para nasal sinuses. It is more common in male. Tumor is diagnosed histologically consisting of both histiocytes and fibroblast cells. Pleomorphic Sarcoma is classified into primary and secondary types with mean age of presentation between 6th and 7th decade. The treatment of choice for this tumor is surgery with clear margins and adjuvant Radiotherapy. Prognosis remains poor even after surgery with local and distant metastasis seen commonly.

Soft Tissue Sarcoma encompasses (STS) a broad array of malignant tumors that are derived from cells of mesenchymal origin at any anatomical site. The originating tissue is diverse that includes bones, cartilage, muscular, fibrous, vascular, fatty and neural tissue.  Of all the soft tissue sarcomas only 5-20% occurs in the head and neck region. The most common STS of the head and neck region are Rhabdomyosarcoma followed by Malignant fibrous Histiocytoma, Fibrosarcoma and Neuro-fibrosarcoma. The incidence of MFH seems to be the highest among various types of adult malignant soft tissue sarcomas.  Pleomorphic Sarcoma or Malignant Fibrous Histiocytoma (MFH) is a rare primitive mesenchymal tumor showing both fibroblastic and histiocytic differentiation. We report a case of Pleomorphic Sarcoma/ MFH and the review of literature in relation to Pleomorphic Sarcoma.

A 40 year old male presented with the chief complaint of gradually progressive, painless, irregular swelling over the right side of the face for the past 6 months. On examination it was a 10 x 8 x 8 cm large firm mass of the right parotid region with no evidence of intra oral lesion. There were no palpable neck glands. On radiological evaluation, CT scan revealed a 98 x 113x 106 mm enhancing soft tissue lesion over the right parotid region. Lesion showed area of necrosis within. Lesion reaches up to the skin and involves the masseter muscle. Right submandibular gland is not seen separately from the lesion. Presence of few lymph nodes at level IA, II, III with the largest at IA measuring 20 x17 mm. No evidence of mandible erosion.

Tuesday, 20 February 2018

HLA-G 14 bp Polymorphism and Risk of Pre-Eclampsia

Pre-eclampsia belongs to one of very serious complication during pregnancy. It is a multisystem disorder that is manifested by hypertension, proteinuria and abnormal blood clotting. Advanced clinical symptoms include seizures, renal failure, IUGR (Intrauterine Growth Restriction) and/or HELLP (Hemolysis, Elevated Liver Enzymes and Low Platelets) syndrome. Finally the generalized damage of the maternal endothelium, kidneys and liver can develop leading to increased mortality of mother as well as foetus. The clinical symptoms of pre-eclampsia can be observed in the second or the third trimester in pregnancy and are the most common in primiparas. Clinical features of PE are studied by Doppler flowmetry not only in foetal and foetoplacental circulation as well as in maternal organs, i.e. uterine  cerebral ophthalmic and renal vessels. Stiffness metabolic syndrome and risk of CVD are other clinical research topics.
Despite many research studies, the pathology of pre-eclampsia is not fully understood. One cause may originate in an insufficiently developed placenta, referred to as poor placentation. It is characterized by impaired remodeling of spiral arteries of the uterus (endothelial dysfunction) caused by an imbalance of circulating angiogenic factors. High circulating levels of soluble Fms like tyrosine kinase 1 (sFlt1) and soluble endoglin (sEng), a circulating receptor or TGFbeta, (both anti-angiogenic factors) and low levels of circulating Vascular Endothelial Growth Factor (VEGF) and Placental Growth Factor (PlGF) (both pro-angiogenic factors) have been described.
There are also immunological factors that can induce pregnancy disorders including pre-eclampsia. One of the immune molecules that play a beneficial role in the pregnancy is the Human Leukocyte Antigen G (HLA-G). HLA-G is a non-classical HLA class I protein that exerts various immunosuppressive functions. The molecule is mainly expressed on trophoblast cells in the foetal placenta and induces the immune tolerance of foetus. Immunosuppressive activity of HLA-G molecule is mediated through its interaction with inhibitory receptors of immune cells: ILT-2 present on B, APC and some T, NK cells, ILT-4 on APC and KIR2DL4 expressed by NK and some T cells. Thus HLA-G mediates inhibition of cytotoxic activity of uterine and peripheral blood NK cells and CD8+ T cells, inhibition of all proliferative response of CD4+ T cells; inhibition of Dendritic cells maturation and activates regulatory T cells.

Monday, 19 February 2018

Gender Disparity in Hepatitis: A New Task in the Challenge Against Viral Infection

Gender/sex-specific medicine is still a neglected field of investigation, which is devoted to the analysis of the disparity between men and women in disease pathogenesis and prevention, in the detection of clinical signs or symptoms, in the prognosis and response to therapy as well as in psychological and social determinants of morbidity. For instance, it is well documented that incidence and outcome of several human diseases, such as cardiovascular diseases, tumors, degenerative diseases, or some respiratory and neurological disorders display a significant disparity between males and females [1-4]. In addition, it is now emerging that men and women also experience a different susceptibility to some virus infections, often with a different outcome. In addition, even the prevention or the response to antiviral treatments can display significant differences between male and female patients.

Hepatitis B (HBV) and C viruses (HCV) are responsible of chronic liver disease and are the major risk factors for development of hepatocellular carcinoma (HCC) [6]. It is estimated that 240 million people worldwide are chronically infected with HBV and at risk of serious illness, like cirrhosis and HCC. One hundred seventy million people are estimated to be chronically infected with HCV, whose infection prevalence is about 3% in the developed countries whereas, only in Europe, about 4 million people are HCV carriers [7,8]. Beside these epidemiological data, sex disparity in the natural history of HBV and HCV infections and in the evolution and progression of the associated liver disease in different geographic areas of the world [9] have been reported since many.

A number of studies are available regarding gender differences in HBV infection, whereas HCV infection appears studied in less detail. After the initial knowledge that men are more likely than women to become chronic carriers for HBV [11], it has been recognized that the serum prevalence of HBV surface antigen (HBsAg) and the DNA virus titers are higher in serum of men than women [12,13]. Both these viral factors probably contribute to the increased risk to develop HCC in male with respect to female. 

Friday, 16 February 2018

Hodgkin Lymphoma Presenting with Dural Involvement

HodgkinLymphoma (HL) is a B-cell neoplasm that rarely presents with central nervous system (CNS) extranodal manifestation. This presentation can occur as relapsed disease as well as at initial diagnosis. In this report, we present a patient with dural involvement of HL. Systemic chemotherapy with ABVD (doxorubicin, bleomycin, vinblastine, and decarbazine) in addition to intrathecal therapy (IT) with intrathecal chemotherapy may be a treatment option for patients with isolated dural involvement with CNS HL. There is no current consensus for treatment modality of CNS HL, however, our patient with dural disease was successfully treated with ABVD systemic chemotherapy and IT MTX and ARA-C and is now >12 months in an ongoing remission. The role of CNS penetrating agents for isolated dural involvement is unclear given it is not protected by the blood brain barrier (BBB). As evidenced by this case with appropriate therapy patients can achieve complete remission (CR) in CNS HL.

Hodgkin Lymphoma (HL) is a B-cell neoplasm that typically presents with enlarged lymph nodes and “B” symptoms. Many patients at presentation will have advanced disease and some will develop extranodal lesions. Central nervous system (CNS) involvement is an extremely rare extranodal manifestation of HL occurring at a frequency of 0.02-0.7% in patients. Although rare, there have been several cases describing CNS HL. The current knowledge of CNS HL and treatment approach is mostly derived from these case reports. Treatment has often included radiation, systemic chemotherapy, surgical resection, and combined modality therapy; however, no consensus has been reached about the best treatment option. Despite aggressive treatments, overall prognosis in patients with CNS HL is poor. In our case, we describe a patient with HL presenting with dural involvement.
A 38 year old male presented with a 5 week history of new onset headache. 

The patient underwent a magnetic resonance imaging (MRI) brain scan which demonstrated dural thickening, and enhancement along the anterior falx and the right tentorium (Figure 1A and D). Imaging was concerning for an infectious, inflammatory, or neoplastic process. He had a lumbar puncture, which was negative for infection and malignancy by flow cytometry and cytology. A bone marrow biopsy demonstrated hypocellularity with normal karyotype with no evidence of malignancy. The patient then underwent a computed tomography (CT) neck/chest/abdomen/pelvis and positron emission tomography (PET) scan, which demonstrated a single enlarged FDG-avid supraclavicular node (Figure 1G). The node was excised, and pathology demonstrated a lymph node with effaced architecture and nodules surrounded by thick collagen bands. These nodules were comprised of small lymphocytes with interspersed large mono- or binucleated Reed-Sternberg cells with prominent eosinophilic nucleoli and abundant light eosinophilic cytoplasm. There was focal retraction artifact present around the large cells, as well as scattered “mummified” cells. The Reed-Sternberg cells were CD15+ and CD30+, weakly PAX-5+, CD3-, CD20-, and CD45- . Background lymphocytes were composed of CD3+ T-cells and CD20+ B-cells. The excised lymph node pathology was diagnostic for nodular sclerosis classical HL (Figure 2). The patient was referred to oncology.

Thursday, 15 February 2018

Macroscopic Balance Equations for Spatial or Temporal Scales of Porous Media Hydrodynamic Modeling


Wefocus on the first author’s previous work addressing macroscopic balance equations developed for different spatial and temporal scales. We elaborate on previous findings so as to orient the reader to fundamental concepts with which the mathematical formulations are developed. The macroscopic balance Partial Differential Equations (PDE’s) are obtained from their microscopic counterparts by volume averaging over a Representative Elementary Volume (REV), considering a non-Brownian motion. The macroscopic quantity of phase/component intensive quantities product, is the premise of two concurrent decomposed macroscopic balance PDE’s of the corresponding extensive quantity. These are concurrently valid at the primary REV order of length and at a significantly smaller secondary length. The hydrodynamic characteristic at the smaller spatial scale was found to always be described by pure hyperbolic PDE’s, the solution of which presents displacement of sharp fronts. Reported field observations of condensed colloidal parcels motion, validate the suggestion of hyperbolic PDE’s describing fluid momentum and components mass balance at the smaller spatial scale. Controlled experiments supplemented by numerical predication can yield the hydrodynamic interrelation between the two adjacent spatial scales.

Further, we focus on the first author past developments concerning dominant macroscopic balance PDE’s of a phase mass and momentum and a component mass following an onset of abrupt pressure change. These account for the primary REV order of length and for evolving temporal scales. Numerical simulations were found to be consistent in excellent agreement with experimental observations. During the second time increment and in view of the aforementioned developments, we presently elaborate on new findings addressing theoretically the efficiency of expansion wave for extracting solute from a saturated matrix. Simulations comparing between pumping using an approximate analytical form based on Darcy’s equation and numerical prediction addressing the emitting of an expansion wave, suggest that the latter extracts by far more solute mass for a spectrum of different porous media.

Application of spatial averaging rules, referring to a REV, leads to the formulation of the macroscopic balance equations addressing phase interactions such as fluids carrying components and a deformable porous matrix. Further elaborations by Sorek et al. Sorek and Ronen and Sorek et al. prove that the phases and components macroscopic balance PDE’s can be decomposed into a primary part that refers to the REV length scale and, concurrently, a secondary part valid at a length scale smaller than that of the corresponding REV length. The secondary macroscopic balance equation always conforms to a hyperbolic PDE. Geometrical patterns of different spatial scales that prevail in various porous media are exemplified in Figure 1. Such patterns support the notion of the need to implement macroscopic balance equations addressing different spatial scales. Observations verify that the hydrodynamic characterization of colloidal transport comply with the developed fluid and component macroscopic balance equations for the smaller spatial scale.

Wednesday, 14 February 2018

Local Understanding and Responses to Deliberate Transmission of HIV: Experiences from Persons Receiving Antiretroviral Treatment in Rural Northeastern Tanzania

As access to Antiretroviral Therapy (ART) in Tanzania has been steadily improving in recent years, there has been concern that availability of Antiretroviral Drugs (ARV) could fuel HIV transmission due to deliberate unprotected sexual practices of persons receiving antiretroviral treatment. There has been a debate about the need to enforce some institutional measures to help manage and control what has been described as the deliberate spread of HIV. However, there is no widespread consensus about what constitutes ‘deliberate transmission’.
Drawing on in-depth interviews with a sample of people receiving ART and health workers providing care in a rural setting, this article examines the context in which deliberate HIV transmission is defined and the ways through which it can be controlled. The article demonstrates that people on ART face the dilemma of reducing risk of spreading HIV and a desire to maintain socially acceptable sexual and reproductive lives. Although many participants reportedly remained sexually abstinent, they also revealed that some people on treatment from within and beyond the study area were engaging in sexual behaviours perceived to amount to deliberate spread of HIV.
Despite some reservations, formal sanctions to control deliberate HIV transmission were generally highly approved by participants. The article strongly recommends for a careful examination of needs of persons on treatment and strengthened prevention in order to manage unintended consequences of ART for individuals living with HIV/AIDS and uninfected population.