Aims: Venous invasion is an established predictor of prognosis in colorectal cancer (CRC). The reported incidence of venous invasion in CRC specimens varies between 10% and 89.5%, mainly as a result of interobserver variability and differences in specimen processing (for example, staining with haematoxylin and eosin (H+E) alone versus the addition of an elastic fibre stain). This study was performed with three purposes in mind, namely: (1) To assess and compare the incidence of venous invasion diagnosed on H+E stained tissue versus tissue stained with both H+E and an elastic fibre stain. (2) To estimate the inherent false negative rate associated with the diagnosis of venous invasion by histopathological evaluation of resected CRC specimens. (3) To compare the resulting data regarding incidence, quantity, site, and type of venous invasion to the pertinent literature. Methods: Venous invasion was assessed on sections from 81 CRCs resected from patients with synchronous distant metastases (hepatic and non-hepatic). Only stage IV tumours were studied for the following reasons: (1) it can be assumed that in all patients with distant haematogenous metastases venous invasion had occurred, thus enabling the false negative rate to be calculated; (2) there can be no dispute about the clinical relevance of the various characteristics of venous invasion identified in the tumours of patients with synchronous distant haematogenous metastases; and (3) to eliminate the effect of variance in tumour stage on the incidence of venous invasion. Initially, H+E stained sections were studied for venous invasion. Sections that were negative or questionable with regard to venous invasion were then stained with an elastic fibre stain, and a second search for venous invasion was carried out. Venous invasion was characterised by incidence, quantity, type, and site. The χ 2 test for independence was used to compare the incidence of venous invasion in colonic versus rectal and rectosigmoid primary tumours, and in patients with hepatic versus non-hepatic metastases. Results: Venous invasion was identified in 42 (51.9%) (of the 81 specimens on H+E stained sections. The addition of the elastic fibre stain enabled the diagnosis of venous invasion in 15 (38.5%) of the remaining 39 specimens, increasing the overall incidence to 57 of 81 cases (70.4%). Of the 57 positive specimens, venous invasion was minimal in 27 (47.4%), intermediate in five, (8.8%) and massive in 25 (43.9%). Only intramural veins were involved in 18 (31.6%), only extramural veins in 26 (45.6%), and both intramural and extramural veins in 13 (22.8%) of the 57 positive specimens. The filling type of venous invasion was found in 41 (71.9%), the floating type in 28 (49.1%), and the infiltrating type in six (10.5%) of the 57 positive specimens. There was no significant difference between the incidence of venous invasion in the colon (42 of 60; 70%) versus rectal and rectosigmoid tumours (15 of 21; 71.4%; p = 0.8539), nor in the incidence of venous invasion in patients with hepatic (...

We isolated a Rhizobium leguminosarum mutant strain altered in the glnB gene. This event, which has never been described in the Rhizobiaceae, is rare in comparison to mutants isolated in the contiguous gene, glnA. The glnB mutation removes the glnBA promoter but in vivo does not prevent glnA expression from its own promoter, which is not nitrogen regulated. The glnB mutant strain does not grow on nitrate as a sole nitrogen source and it is Nod+, Fix+. Two -24/-12 promoters, for the glnII and glnBA genes, are constitutively expressed in the glnB mutant, while two -35/-10-like promoters for glnA and ntrBC are unaffected. We propose that the glnB gene product, the PII protein, plays a negative role in the ability of NtrC to activate transcription from its target promoters and a positive role in the mechanism of nitrate utilization.

The exact causative factor(s) of bone erosion in cholesteatoma are not known. In recent years, the possible role of cytokines has drawn attention. Since the studies on cytokines in cholesteatoma are limited and depend on histopathological methods, the present work approached this subject by biochemical determination of TNF-α lysosomal enzymes, acid phosphatase (total and tartrate resistant), cathepsin B, leucyl aminopeptidase lysozyme together with non-lysosomal enzymes calpain I and II in 50 cholesteatoma samples (epithelial and subepithelial tissues) in comparison with 14 normal skin samples from the external ear canal. The study revealed significantly increased levels of all previous indices in cholesteatoma epithelium and subepithelial tissues compared with healthy skin. The levels of these indices reflected the clinical severity of the disease as reflected by their significant increase in cases with erosion of two or three ossicles, erosion of dural plate, sinus plate and facial canal and more extensive cholesteatoma. It is likely that TNF-α acts both directly by causing bone erosion and indirectly by stimulating the release of lysosomal enzymes. The latter mechanism is supported by the significant correlations observed between TNF-α and lysosomal enzymes. The non-lysosomal enzymes calpain I and II seem to participate in the bone erosion associated with cholesteatoma by their involvement in collagen destruction. Due to the suggested role of TNF-α in bone destruction associated with cholesteatoma the use of anti-inflammatory drugs should be taken into consideration in otitis media to diminish bone destruction. Similarly, antibiotics should be used to prevent the deleterious effects of bacterial endotoxin.

Background: Venous invasion (VI) is an important prognosis predictor after colorectal carcinoma (CRC) resection, enabling more accurate staging and influencing postoperative management. Aims: To assess/compare various tissue block types (perpendicular, tangential, across mesentery (AM), from major vessels or lymph nodes (LNs)) for VI detection in CRC. Methods: Fifty two CRCs (51 colectomies, one polypectomy) were studied. Tumours were measured, surface area calculated, and colorectum and bowel wall sites recorded. Weigert's staining for elastin facilitated VI detection. VI sites, type, and amount were recorded. Ratios of relative yield of tissue block types to their frequency were calculated. Results: Average numbers of tissue blocks/colectomy specimen were: perpendicular, 10.2; tangential, 9.1; AM, 3.3; from major vessels, 2.1. Average number of LNs examined was 16.47. VI was detected in 22 tumours. Overall, VI was detected in 16 perpendicular, seven tangential, five AM, and two LN blocks. VI was detected in eight, two, one, and three tumours in perpendicular, tangential, LN, and AM blocks alone, respectively. In seven tumours, VI was identified in multiple tissue block types. The average number of blocks obtained was 39.7, 42.1, and 38 from all tumours, VI positive, and VI negative tumours, respectively (p = 0.0497). Efficacy to detect VI was 2.151, 2.088, 1.092, 0.172, and 0 for AM, perpendicular, tangential, LN, and mesenteric vessel blocks, respectively. Conclusions: VI was identified most frequently and in eight cases only in perpendicular blocks. However, extramural VI was detected in six tumours only in blocks cut tangentially, AM, or from harvested LNs. Hence, all these types of blocks should be submitted routinely and scanned for VI.

Permeabilization with cetyl trimethyl ammonium bromide was used to study the post‐translational modification of the PII protein in Rhizobium leguminosarum. Upon incubation with radioactive UTP a single band was obtained after SDS‐PAGE and autoradiography. RNase resistance and snake venom phosphodiesterase sensivity showed that radioactivity was bound through a phosphodiester bond to a protein which was absorbed by an antiserum specific for the PII protein. Uridylylation of the PII protein was shown to be dependent on the modifications of the glutamine/α‐ketoglutarate ratio.

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Background: Routine mobilization of splenic flexure whether partial or complete became an essential step in laparoscopic low anterior resections in order to perform an oncologic re­section and to achieve a safe, tension-free anastomosis.Methods: 60 patients with rectal cancer were operated by laparoscopic low anterior resection with high ligation of inferior mesenteric artery in general surgery department, Menoufia university hospital between February 2016 and January 2019. All patients were divided randomly into 2 equal groups based on the techniques used in splenic flexure mobilization whether partial (group A) or complete (group B).Results: The majority of our patients were male 56.6% and 60% in both groups respectively with mean age (54.6±8.8) years in group A and mean age (58.5±9.2) years in group B. The operative time was highly significant lower in group A (269±17.6 minutes) than group B (304±22.4 minutes) while the conversion rate was significantly higher in group B (26.6%) than group A (6.6%). Regarding the postoperative data there was only significantly higher leak from the anastomosis in group A (20%) than group B (3.3%).Conclusions: Complete splenic flexure offer better oncological outcome and low incidence of anastomotic leak but with higher conversion rate, prolonged operative time, more blood loss and more 30 day mortality rate. So it needs more time to gain more experience to overcome these disadvantages.

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