Colloid cyst of the third ventricle presenting with features of Terson's syndrome.

This report describes a middle-aged man presenting to the ophthalmologist with history of seeing floaters before both eyes since 2-weeks duration. A history of intermittent headache and dizziness of recent onset was elicited on questioning. Ocular examination showed bilateral early papilloedema and mild vitreous hemorrhage. Brain computed tomography (CT) disclosed features suggestive of colloid cyst of the third ventricle in the region of foramen of Monro with moderate hydrocephalus. Emergency craniotomy and excision of the cyst was done, and the patient is doing well for the last 18 months after the surgical intervention. The mechanism of this presentation, importance of early investigations, and timely intervention are highlighted in order to avoid serious neurological sequelae. The literature was extensively reviewed for atypical presentations of intraventricular colloid cyst.

Molecular surveillance of putative virulence factors and antibiotic resistance in Staphylococcus aureus isolates recovered from intra-mammary infections of river buffaloes.

In dairy and healthcare surroundings, Staphylococcus aureus has been documented as a leading pathogen. Prevalence of drugs resistant strains in mastitic ruminants is another serious problem. To elucidate the antibiotic-resistant and virulence gene patterns, S. aureus isolates (111) were recovered from intra-mammary infections suffering buffaloes, and characterized using PCR and disk diffusion assays. The pathogenic factors were associated with antibiotic-resistant patterns and analyzed. Molecular and phenotypic characterization of tested isolates showed significantly resistance to tetracycline, macrolides, lincosamides and aminoglycosides. MecA gene was detected in 5.4% of isolates of S. aureus. The isolates showed variation in expression of pathogenic factors. Coagulase genotype VI showed high antibiotics susceptibility while patterns I, III, IV and V belonged to resistant category of tested bacterial population. The prevalence of other virulent genes namely, Ebp, Fib, FnbB, Bbp and Map were present significantly in highly pathogenic isolates. The isolates (41.4%) were found positive for super-antigen enterotoxins Sec, See, Seg and Sei genes only and predominated in methicillin-susceptible compared to resistant ones. The allelic variants of Agr-1 and 3 were considerably associated with coagulase genotypes and other virulence factors, while the enterotoxins were found considerably associated with Agr-1 and 2. Distribution of virulent genes between methicillin-susceptible and resistant isolates was uneven. The distribution of high pathogenic characteristic in antibiotic-susceptible isolates indicated that these were equally responsible in maintaining the intra-mammary infections in animals and cannot be overlooked. The surveillance of pathogenic and antibiotics resistance factors of isolates revealed that certain genetic elements were over producing (Ebp, Fib, FnbB, Bbp, Map, TetK, MsrB, AacA-D) in mastitic S. aureus isolates especially from clinical cases. This outcome or genetic frame of S. aureus isolates may be further use for culling or segregation of animals infected with harmful strains to reduce the dissemination of pathogenic microorganisms or containment of mastitis.

Quorum sensing and expression of virulence in Escherichia coli O157:H7.

Enterohaemorrhagic Escherichia coli O157:H7 causes a characteristic histopathology in intestinal cells known as attaching and effacing lesion. The genes for the lesion are encoded by the Locus of Enterocyte Effacement (LEE) pathogenicity island, that encodes a type III secretion system, the intimin intestinal colonization factor, and the translocated intimin receptor protein that is translocated from the bacterium to the host epithelial cells. Expression of the operons encoded within LEE is complex, but recent studies have demonstrated that quorum sensing influences transcription from four of the LEE operon promoters. A transcriptional regulator (LuxR homologue), signal synthase (LuxI homologue), and autoinducer (acylhomoserine lactone) are indispensable for this system in most gram-negative bacteria. Vibrio harveyi, a gram-negative bioluminescent marine bacterium, regulates light production in response to two autoinducers (AI-1 and AI-2). AI-1 is a homoserine lactone produced by most gram-negative bacteria. The structure of AI-2 is not known, but many species of gram positive and gram-negative bacteria, including E. coli and more specifically O157:H7, have been shown to produce AI-2 depending on the function encoded by the luxS gene. The LuxS acts as an AI-2 synthase and the AI-2 is produced from S-adenosylmethionine in three enzymatic steps. The substrate for LuxS is S-ribosylhomocysteine, which is cleaved to form two products, one of which is homocysteine, and the other is AI-2. The biosynthetic pathways and the biochemical intermediates in AI-2 biosynthesis have been observed to be identical in several gram-negative bacteria, such as E. coli, Salmonella typhimurium, V. harveyi, Vibrio cholerae, and Enterococcus faecalis. Thus, unlike quorum sensing via the family of related homoserine autoinducers, AI-2 is a universal signal, which may be used by a variety of bacteria for communication among and between species and may be responsible for regulation of virulence genes in E. coli O157:H7.

Repair and recovery of thermally injured cells of Yersinia enterocolitica in milk.

One standard strain of the organism MTCC-861 and the two culture isolates VRW-22 and CRW-15 were exposed to batch pasteurization (62.8 degrees C for 30 min) in brain heart infusion broth, skim milk, and whole milk. The trials were repeated three times. None of the isolates survived pasteurization treatment. However, the studies were further directed toward the repair and recovery of thermally injured cells, if any, in peptone sorbitol bile broth, skim milk, and whole milk. The results revealed that only a low number of test cultures were recovered in peptone sorbitol bile broth after 8 days of incubation at 10 degrees C. On the other hand, the recovery was still slower in skim and whole milk, with a detection of the test isolates only on 10 days of incubation under similar conditions.

Significance of microbial biofilms in food industry: a review.

Biofilms have been of considerable interest in the context of food hygiene. Of special significance is the ability of microorganisms to attach and grow on food and food-contact surfaces under favourable conditions. Biofilm formation is a dynamic process and different mechanisms are involved in their attachment and growth. Extracellular polymeric substances play an important role in the attachment and colonization of microorganisms to food-contact surfaces. Various techniques have been adopted for the proper study and understanding of biofilm attachment and control. If the microorganisms from food-contact surfaces are not completely removed, they may lead to biofilm formation and also increase the biotransfer potential. Therefore, various preventive and control strategies like hygienic plant lay-out and design of equipment, choice of materials, correct use and selection of detergents and disinfectants coupled with physical methods can be suitably applied for controlling biofilm formation on food-contact surfaces. In addition, bacteriocins and enzymes are gaining importance and have an unique potential in the food industry for the effective biocontrol and removal of biofilms. These newer biocontrol strategies are considered important for the maintenance of biofilm-free systems, for quality and safety of foods.

Airway simulation to guide stent placement for tracheobronchial obstruction in lung cancer.

BACKGROUND: To effectively palliate large airway obstruction in advanced unresectable lung cancer (stage IIIB or IV), we developed an airway imaging technique to guide selective endobronchial metallic stent placement. METHODS: Fourteen consecutive patients with severe dyspnea (American Thoracic Society grade 4) had a combination of fiberoptic bronchoscopy, chest roentgenography, computed tomographic scanning, helical computed tomography with three-dimensional reconstruction, and intraluminal bronchography with selective bronchial guidewire placement under fluoroscopy to visually reconstruct and simulate the abnormal airway before and during stent placement. Wallstent or Gianturco intraluminal stents were used alone or in combination (up to five stents) to establish patency of the distal trachea and the major bronchi. RESULTS: All 14 patients had successful deployment with initial relief of airway stenosis (>75% predicted diameter). No procedural complications were noted. However, technical problems included stent foreshortening and imprecision of placement, misinterpretation of bronchography (mucous versus tumor), and airway maintenance during manipulation. Length of stay attributable to the procedure averaged 4 days. Stent placement initially improved the dyspnea score in 7 of 14 patients. Five of 14 died in less than 1 month, with the remainder alive at up to 8 months' follow-up. Of those surviving more than 1 month, the Karnofsky score improved in 4 and was unchanged in 5, with 2 dependent (Karnofsky score <50), 3 functional (Karnofsky score, 50 to 70), and 4 active (Karnofsky score >70). CONCLUSIONS: A protocol combining helical computed tomography with three-dimensional reconstruction, bronchography, and bronchoscopy allows accurate assessment of malignant airway obstruction to facilitate intralumenal stent placement for relief of stenosis. Patient selection to favor effective palliation and cost effectiveness has yet to be defined.

The effect of chronic furosemide administration on urinary calcium excretion and calcium balance in growing rats.

The study was designed to determine the calciuretic effect of furosemide and its impact upon calcium balance during chronic (25 days) furosemide administration to growing rats. Experiments were performed on 18 six-wk-old rats. Nine animals received furosemide, and 9 served as controls. The administration of furosemide in a dose of 40 mg resulted in a significant increase in calcium excretion in the treated group; urinary calcium excretion almost doubled that of the controls during the first 24-hr collection (3.74 +/- 0.44 mg in the treated animals compared with 1.90 +/- 0.15 mg in the controls; P less than 0.05). The average daily urinary calcium excretion during each of four subsequent 6-day periods remained approximately three-fold higher in animals which received furosemide compared with controls (P less than 0.001 for each 6-day period). The furosemide-induced increase in urinary calcium excretion did not diminish with time. Sodium excretion did not significantly increase either acutely or chronically in response to furosemide. Daily urinary volume increased approximately 40 to 60% in the furosemide-treated group compared with that of the controls (P less than 0.001). The cumulative calcium balance in the control group exceeded by 7% that of the furosemide-treated animals [2696.3 +/- 20.8 mg versus 2518.6 +/- 20.1 mg (P less than .001]. The findings indicate that distal nephron compensatory mechanisms effecting sodium conservation following furosemide do not result in similar conservation of calcium. Calcium balance may be deleteriously affected.

Congenital nephrogenic diabetes insipidus in a baby girl.

A 6-week-old girl with fever, hypernatraemia, dehydration, and polyuria failed to concentrate urine in response to exogenous vasopressin administration. There was no family history of nephrogenic diabetes insipidus. When she was 15 months old, the infusion of vasopressin did not produce an increase in urinary cyclic-AMP.