Increase of chromium tolerance in Scenedesmus acutus after sulfur starvation: Chromium uptake and compartmentalization in two strains with different sensitivities to Cr(VI).

In photosynthetic organisms sulfate constitutes the main sulfur source for the biosynthesis of GSH and its precursor Cys. Hence, sulfur availability can modulate the capacity to cope with environmental stresses, a phenomenon known as SIR/SED (Sulfur Induced Resistance or Sulfur Enhanced Defence). Since chromate may compete for sulfate transport into the cells, in this study chromium accumulation and tolerance were investigated in relation to sulfur availability in two strains of the unicellular green alga Scenedesmus acutus with different Cr-sensitivities. Paradoxically, sulfur deprivation has been demonstrated to induce a transient increase of Cr-tolerance in both strains. Sulfur deprivation is known to enhance the sulfate uptake/assimilation pathway leading to important consequences on Cr-tolerance: (i) reduced chromate uptake due to the induction of high affinity sulfate transporters (ii) higher production of cysteine and GSH which can play a role both through the formation of unsoluble complexes and their sequestration in inert compartments. To investigate the role of the above mentioned mechanisms, Cr accumulation in total cells and in different cell compartments (cell wall, membranes, soluble and miscellaneous fractions) was analyzed in both sulfur-starved and unstarved cells. Both strains mainly accumulated chromium in the soluble fraction, but the uptake was higher in the wild-type. In this type a short period of sulfur starvation before Cr(VI) treatment lowered chromium accumulation to the level observed in the unstarved Cr-tolerant strain, in which Cr uptake seems instead less influenced by S-starvation, since no significant decrease was observed. The increase in Cr-tolerance following S-starvation seems thus to rely on different mechanisms in the two strains, suggesting the induction of a mechanism constitutively active in the Cr-tolerant strain, maybe a high affinity sulfate transporter also in the wild-type. Changes observed in the cell wall and membrane fractions suggest a strong involvement of these compartments in Cr-tolerance increase following S-starvation.

Topographic mapping of the brain activity of perceived motion.

The study compared electrical brain activity of 6 subjects in 5 different conditions. Absolute theta and alpha power in the frontal, parietal, and occipital areas were analyzed, with significant differences found only in the frontal area. Results suggested that the perception of movement requires higher order cognitive processing outside the occipital area. Implications for education and cognitive research are discussed.

Expression of c-myb protooncogene and other cell cycle-related genes in normal and neoplastic human colonic mucosa.

The expression of c-myb, c-myc, histone H3, and ornithine decarboxylase genes was examined by Northern blot analysis in the normal and neoplastic mucosa of ten subjects affected by colon cancer. The mRNA levels of c-myb protooncogene were detected at low levels in all normal samples but were increased in the neoplastic mucosa of six cases in comparison to the normal counterpart. In five of these six cases the mRNA levels of c-myc, histone H3, and ornithine decarboxylase mRNAs were also increased, suggesting that there is a relation between the high expression of c-myb and the fraction of cycling neoplastic cells.

[Benign solitary ulcer and acute diverticulitis of the cecum]. / L'ulcera solitaria benigna e la diverticolite acuta del ceco.

The report of diverticulosis of right colon in a patient formerly operated on for perforation of caecum single ulcer appeared to the authors as a confirmation of a common etiology between both lesions. The single ulcer would probably represent a form of manifestation for the acute phlogosis of a diverticulum.

[Acute appendicitis and its postoperative complications. Apropos of a series of 8738 cases]. / L'appendicite aiguë et ses complications post-opératoires. A propos d'une série de 8738 cas.

8,738 cases of acute appendicitis, all operated on emergency, have been examined considering their total mortality (3 cases), and their post-operative complications (2.04%), secondary especially to the septic character of this disease. Diagnosis and treatment of acute appendicitis still require a particular attention and care.

[Villous adenoma of the duodenum]. / Gli adenomi villosi del duodeno.

The authors study the diagnostical problems, especially those involved in the preoperative diagnosis of malignancy, of four cases of duodenal villous adenoma. A more frequent use of endoscopy can allow the observation of this lesion in early stage, such as to ensure recovery through an intervention as scarcely demolishing as possible. However, surgeons plotting the strategy of operation should bear in mind the potential malignancy of duodenal villous adenoma.

Medical treatment of biliary duct stones: effect of ursodeoxycholic acid administration.

Twenty-eight patients with radiolucent biliary duct stones without cholangitis and jaundice were randomly allocated into two treatment groups receiving ursodeoxycholic acid 12 mg/kg (group A) or placebo (group B) in three daily doses for 24 months. In group A stones disappeared completely in seven patients and partially in one; placebo administration had no effect on stone size and three patients of group B (only one of group A) went to surgery for complications. Ursodeoxycholic acid treatment did not adversely affect liver function tests, and alkaline phosphatase decreased. Abdominal and biliary colics also became less frequent in the first six months of therapy in group A, but not in the placebo group. The bile was supersaturated with cholesterol in both groups, but decreased significantly only in patients receiving ursodeoxycholic acid even though the lithogenic index remained high. Cholesterol saturation of bile does not seem to be the only factor determining the dissolution of biliary duct stones which sometimes contain cholesterol as the main component.

[Closed abdominal injuries in patients with multiple injuries. Diagnostic considerations on 74 cases]. / Sui traumi chiusi addominali nel politraumatizzato. Considerazioni diagnostiche su 74 casi.

A diagnostic assessment was made of 74 cases of non-penetrating abdominal wounds observed over the previous 5 years. Laparoscopy performed in 49 polytraumatised patients made a decisive contribution to accurate, early diagnosis, with an indication for emergency surgery in 35 cases (32 visceral lesions and 3 retroperitoneal haematoma), whereas it was clear from the negative finding that surgery was not required in the remaining 14. It is felt that all additional radiological and instrumental diagnostic should be employed, and that careful clinical examination and repeated inspection, preferably by the same surgeon, are important in cases of multiple injury, since the situation may become dramatically worse in the space of a few hours.

[Acute postoperative necrotizing enteritis. Apropos of one case after total hysterectomy with bilateral annexectomy]. / Entérite aiguë nécrosante post-opératoire. A propos d'une observation après hystérectomie totale avec annexectomie bilatérale

The authors report a case of acute necrotising enteritis occurring on the 7th day after total hysterectomy with bilateral removal of the adnexa for fibroids in a 45 year-old woman. This is the first case in the literature to occur after hysterectomy. The clinical picture included the onset of intestinal obstruction with severe general toxic manifestations. The diagnosis was made at operation and, in spite of intestinal resection, the patient died on the 6th day, with liver and renal failure, anuria and irreversible collapse. The blood and stool cultures were negative, but the histological appearance of the lesions, without any apparent suppuration, were in favour of a vascular etiology. Necrosis of the mucosa and inflammatory oedema of the sub-mucosa, were accompanied by vascular changes suggesting thrombosis and congestion.