Hepatitis B and primary cancer of the liver in intertropical Africa

During the past 15 years, a growing body of evidence incriminates hepatitis B virus as the major factor in the etiology of primary liver cancer. Epidemiological studies throughout the world reported a striking correspondence between areas where the frequency of primary liver cancer is high and where HBV infection is hyperendemic. Moreover, primary liver cancer is commonly associated with cirrhosis of the postnecrotic macronodular type. Such data suggested a sequence hepatitis-cirrhosis-PLC. Such sequence was confirmed by extensive serologic testing studies which reported a high frequency of HBV markers in PLC patients compared to matched control groups. Data collected in Senegal, Mali and Burundi on 12,000 individuals stress the importance of HBV infections in these countries, as the high rate of chronic carrier state in patients suffering from liver cirrhosis or primary liver cancer (62-63%) compared to the general population (12-17%). Other HBV markers including anti-HBs, anti-HBc, HBeAg and anti-HBe had no prognostic value in the sequence hepatitis-cirrhosis-PLC. A new HBV seric marker, the HBsAg/IgM complexes, observed in HBsAg positive individuals, is more frequently detected in PLC patients (50%) and cirrhosis (40%) than in healthy HBsAg carriers (14%). These results would indicate that HBsAg carriers are more likely to develop cirrhosis or primary liver cancer when they evidence HBsAg/IgM complexes. In conclusion, the seric markers of evolution towards primary liver cancer are: HBsAg (the highest known risk factor), the presence in such individuals of HBsAg/IgM complexes, and increased values of alphafoetoprotein.     

Natural occurrence of ochratoxin A in food and feed in Senegal.

A retrospective study covering 1984-88 showed that urogenital diseases were the third most frequent cause of death in Senegal. The purpose of our study was to see whether ochratoxin A is involved in the etiology of these nephropathies. A total of 166 samples of eight principal types of food and feed consumed in this country were obtained randomly at markets in Dakar and Kaolack and analysed for ochratoxin A using the method of analysis of the Association of Official Analytical Chemists. Only cowpea (Vigna unguiculata), from a legume widely distributed in Senegal, was contaminated (16% of samples), at an average level of 34 micrograms/kg. All other samples were free of ochratoxin A, indicating that it is not directly correlated with the renal diseases observed. Aflatoxin B1 was detected in almost all of the samples, and a competition between moulds producing the two toxins is suggested.     

Melting temperatures and enthalpies of polyethers, 2. Poly(octamethylene oxide)

The dependence of the melting temperature on the crystallization temperature for low molecular weight fractions of poly(octamethylene oxide), (poly(oxyoctamethylene)), in the range from M _n = 3400 to M _n = 9 000, is analyzed. It is found that in this molecular weight region, the extrapolated linear relation melting temperature T_m vs. crystallization temperature T_c, for high levels of crystallinity yields an equilibrium temperature, which is in good accord with theoretical expectations; meanwhile the T_m vs. T_c relation for low levels of crystallinity leads to higher equilibrium temperatures. The equilibrium melting temperature corresponds to 356 K for M _n = 9 000 and the enthalpy of fusion was found to be 60,5 cal/g (= 253 J/g).     

Intestinal obstruction caused by postoperative adhesion. 79 cases]

The intestinal post-operative bridle represents the third most important etiology of obstructions at the clinic of the University Hospital of Dakar, behind hernia strangulations and the volvulus of the digestive tube. Between 1970 and 1989, a retrospective study has led to a sample of 79 patients with post-operative bridle obstructions. The group was made of 47 women and 32 men between 17 and 84 years of age. Stomach ache was by far the most common functional symptomatology, followed by the stoppage of the transit and vomiting. In most cases palpation revealed the presence of tympanism. For almost all the patients, the abdomen without preparation revealed either a hydroaeric level or a diffuse grey area. The initial intervention concerned mainly gynecological affections or pathologies of appendicular type. The resection of the bridles was carried out in most cases. There were 10 deaths. The intestinal obstructions by post-operative bridles continue to be a surgical emergency still characterized by a high mortality rate. The late consultation of the patients, often received when presenting considerable visceral deficiency, is one of the main causes of the high rate of fatalities.     

Latex agglutination test and counterimmunoelectrophoresis in the diagnosis of Haemophilus influenzae meningitis

Authors have searched for Haemophilus influenzae by culture and by detection of capsular antigens in CSF of 1.700 bacterial meningitis in Dakar. Culture has been positive in 71.9%, counter-immunoelectrophoresis in 94.9% and latex (slidex meningitis kit) in 91.2% of cases. Diagnosis results are improved of 39% comparatively with bacteriologic culture. False positive results caused by antigenic cross-reactions have been observed only in 1.3% of others bacterial meningitis. Latex-test is allowing a diagnosis in three minutes and a quantitative determination of antigens (useful for pronostic).     

Kinetics of polymerization of tetrahydrofuran initiated by acetyl perchlorate

The kinetics of the polymerization of tetrahydrofuran by acetyl perchlorate in methylene chloride solution was studied, and the results were compared with those previously reported by using perchloric acid/acetic anhydride as catalyst. The initiation and propagation mechanisms are discussed by taking into account the influence of the counterion. The initiation reaction takes place instantaneously, but the propagation proceeds by macroesters and macroions and the contribution of macroester to propagation is much lower than the contribution of macroions.     

The superficial temporal artery: anatomical type and clinical application to the flap of the fascia temporal superficialis

The goal of our study is to assess the anatomical type of the superficial temporal artery (STA) in the black population using the classification of Ricbourg et al.. Forty-seven fresh cadavers and three extracted and frozen heads were included in this study. The external carotid artery was isolated in the neck and injected by Rhodopas stained with Congo Red. The superficial temporal artery was dissected using a Y-shaped skin incision. The last step of the procedure was to remove the flap of the fascia superficialis temporis. The third segment of the superficial temporal artery and its terminal branches were studied. This segment courses cephalad and wraps the zygomatic arcade. It splits into two terminal branches: the temporo-frontal and the temporo-parietal ones. The most important of its collaterals, the zygomato-maleus artery, plays a crucial role for distinguishing the subtypes of STA according to the classification of Ricbourg et al.. Indeed, this branch can be subdivided into two types: --type I: the zygomato-malar artery arises from the trunk of the STA; it courses perpendicular and with a slightly ascending direction; this type accounts for 93% of the cases. --type II: the zygomato-malar artery originates from the branch of the temporo-frontal artery. Its course is either horizontal or caudad. This type accounts for 3% of the cases. Our results confirm those of Ricbourg et al.. Thus, we could not CONFIRM the notion of a racial predominance of typology of the STA in our context. We did not study the dimensions of STA and also the level of its bifurcation. Indeed, it has been largely reported in the literature. These elements constitute the anatomic basis of the surgical use of temporal flaps. The vessel-containing tissue in which travels the STA forms the so-called fascia temporalis superficialis whose plasticity and polyvalency are critical during the procedures of plastic and reconstructive surgeries.     

Multiple melting temperatures of poly(3,3-diethylthietane)

The melting behaviour of semicrystalline poly(3,3-diethylthiethane) (PDET), was studied by differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), small-angle light scattering (SALS), and thermooptical analysis (TOA). Two samples of number-average molecular weights 6,0 · 10⁴ and 1,8 · 10⁵ and rather narrow molecular weight distributions (ratio of weight-to number-average molecular weights M?_w/M?_n = 1,3) were analyzed. When PDET is isothermally crystallized from the molten state in the range 275–333 K, the calorimetric curves show one or two melting endotherms, depending on crystallization temperature (T_c) and heating rate. WAXS analysis shows conclusively that polymorphism is absent. It was shown that the melting behaviour of PDET is being dictated by processes of melting and recrystallization occurring during the experimental analysis.