Laparoscopy for malignancy: current status

The acceptance of laparoscopy for the management of oncologic disease has been slow because of initial fears regarding the effect of this new approach on the interaction between the patient and the tumor. Since the initial attempts at laparoscopic resection, experience and technology have improved in parallel, facilitating improvements in this area. Laparoscopic oncologic surgery has a role in the management of oncologic patients at all stages of disease. Good evidence exists that laparoscopy has become an invaluable staging tool in many upper gastrointestinal cancers as well as lymphomas. The specter of port-site recurrence has loomed over the use of a laparoscopic approach for curative resections. However, it is clear from many reported trials that the initial prevalence of port-site metastases was more a technical issue rather than a problem with laparoscopy. Current large, multicenter trials will report the true outcomes of laparoscopic colon cancer surgery and its comparison with open surgery. It does appear that laparoscopic cancer surgery is feasible, safe, and oncologically sound. We fully believe that laparoscopic cancer surgery will play an increasingly major role in the management of gastrointestinal malignancies.

Intussusception in a Young Adult With Bloody Diarrhoea

Bloody diarrhoea is a common presenting symptom in acute surgery, medicine and also in out-patient clinics. Intussusception, although a common cause of small bowel obstruction and rectal bleeding in infants, is rare in adults. In contrast to paediatric cases, where the majority can be treated by pneumatic or hydrostatic reduction, the vast majority of adult cases of intussusception are due to a tumour of some kind and will require operation and resection. Diagnostically plain radiology, CT, ultrasound and endoscopy are useful since the clinical picture is often unclear. We present a case of a young man who presented with acute bloody diarrhoea. The diagnosis was made colonoscopically and he was treated surgically. The case underlines the need for surgeon to maintain an open mind when investigating unexceptional symptoms.

Optimization of the isotope-coded affinity tag-labeling procedure for quantitative proteome analysis

The combination of isotope coded affinity tag (ICAT) reagents and tandem mass spectrometry constitutes a new method for quantitative proteomics. It involves the site-specific, covalent labeling of proteins with isotopically normal or heavy ICAT reagents, proteolysis of the combined, labeled protein mixture, followed by the isolation and mass spectrometric analysis of the labeled peptides. The method critically depends on labeling protocols that are specific, quantitative, general, robust, and reproducible. Here we describe the systematic evaluation of important parameters of the labeling protocol and describe optimized labeling conditions. The tested factors include the ICAT reagent concentration, the influence of the protein, SDS, and urea concentrations on the labeling reaction, and the reaction time. We demonstrate that using the optimized conditions specific and quantitative labeling was achieved on standard proteins as well as in complex protein mixtures such as a yeast cell lysate.

Estimating parasite density in patients suffering from falciparum malaria in an endemic area in Kolkata

Parasite density of one hundred patients suffering from falciparum malaria in an endemic area in Kolkata was determined using three different methods. In the first of these, parasite density per microlitre of blood in a patient was determined using parasite count adjusted by average WBC count (i.e. 8000/microliter) observed in microscopic fields of the thick film. In the remaining two methods, only raw (i.e. unadjusted) parasite counts in microscopic fields of the same slide were used. A statistical analysis was carried out in detail to compare these methods based on raw and adjusted parasite counts and also to find out a suitable method which can be used in practice. Estimating the density of parasites is of primary importance in determining the severity of infection. Furthermore, parasite density can help in identifying short-treatment and long-treatment failure vis-a-vis detection of development of resistance in P. falciparum against the drug used. This article reports some findings that indicate the existence of a potentially dangerous situation in the study area.

Multifunctional antigens of A. fumigatus and specific antibodies

The majority of Aspergillus-induced infections in man are caused by the pathogenic fungus A. fumigatus, which secretes biologically and immunologically active glycosylated and nonglycosylated proteins. The complexity in the antigenic structure of A. fumigatus and the varying host immune responses lead to a wide spectrum of clinical conditions such as allergic bronchopulmonary aspergillosis (ABPA), aspergilloma, and invasive aspergillosis. It is reported that 15-20% of allergic asthmatics suffer from Aspergillus-induced allergies. The incidence of opportunistic infections, including Aspergillus infections, has risen because of the increase in the incidence of HIV and tuberculosis. Allergic bronchopulmonary aspergillosis is an immunologically significant clinical form where type I and type III hypersensitivity reactions are involved in pathogenesis. High levels of specific IgE and IgG antibodies in these patients are of diagnostic value. Molecular characterization of certain immunodominant allergens and antigens of A. fumigatus revealed the presence of complex carbohydrate moieties, heat-shock proteins, enzyme activities such as elastase, protease, catalase, dismutase, and cytotoxic ribonuclease. A Con A binding allergen/antigen (45 kDa) and Con A nonbinding allergen/antigen (18 kDa, Asp fI) have a multifunctional nature. The multifunctional nature of these antigens may play an important role in the pathogenesis of the disease. Significant amounts of a major allergen/antigen of molecular weight 18 kDa is excreted in large amounts through the urine of patients with invasive aspergillosis. Studies on the structure-function relationship of the 18-kDa allergen/antigen revealed the involvement of tryptophan residues in binding with monoclonal antibodies (MAbs). Also, the histidine residues and cysteine disulfide bonds of the 18-kDa allergen are involved in its catalytic activity. The high load of multifunctional antigens in the serum of patients for prolonged periods, the presence of high levels of specific antibodies, and the absence of protective antibodies in ABPA patients have necessitated studies on the functional properties of the antibodies. The present study shows significant immunoreactivity of antibodies in patients of ABPA to fibronectin and collagen. Analysis of IgG antibodies from the patients of ABPA showed the presence of DNA-cleaving activity. These observations offer a new line of thinking in understanding the mechanism of pathogenesis of Aspergillus-induced clinical manifestations, and may lead to novel approaches to intervention in the inflammation and infection caused by fungal pathogens.

Expression of an epitopic region of AspfI, an allergen/antigen/cytotoxin of Aspergillus fumigatus

The gene for an 18 kD allergen/cytotoxin of Aspergillus fumigatus was cloned in pUC-19 vector and expressed in Escherichia coli JM109. Digestion of this gene with AluI resulted in four fragments of 216bp, 120bp, 39bp and 21bp. These fragments were cloned in the Sma-I site of pUC-19. The recombinants thus, generated after transformation in E. coli JM109, were screened using monoclonal antibodies raised against the AspfI. The fusion protein containing 120 bp AluI fragment was recognised by the MoAb indicating presence of epitope(s) in the 120 bp region. The study indicates a viable strategy for identification and expression of an immunologically active domain of a major allergen/antigen of A. fumigatus for the first time.

Screening for lower genital tract infections in women presenting for termination of pregnancy

Over a four-month study period, 87 patients requesting termination of pregnancy at a gynaecology clinic were offered screening for sexually transmitted diseases, of whom 63 accepted. A total of 41 infections were found in 34 women, the commonest being vaginal candidiasis and bacterial vaginosis. Chlamydia was found in six patients. Although HIV antibody testing was offered to every patient, all declined this test.

Structure of the carbohydrate chain of free secretory component from human milk

Secretory component from human milk was found to contain 23.4% carbohydrate, which includes galactose, mannose, fucose, glucosamine, and sialic acid. Secretory component could be degraded by pronase or base-borohydride to yield the same, single type of carbohydrate chain. In the glycopeptide produced by pronase digestion, aspartic acid was the only amino acid present in molar quantities after amino acid analysis, which suggests that the carbohydrate moiety is linked to the polypeptide chain at asparagine residues. The positions of links between the various sugar units were studied by methylation analyses of: secretory component, periodate-oxidized and reduced secretory component, the fragment produced by base-borohydride treatment, and the pronase glycopeptide after treatment with specific glycosidases. Sugars released from the glycopeptide by various glycosidases were also quantitated. From the results of these studies a branched chain structure was assigned to the carbohydrate chain of secretory component.