Aberrant expression of nitric oxide synthase in human polyps, neoplastic colonic mucosa and surrounding peritumoral normal mucosa

The expression of nitric oxide synthase (NOS) was studied byNAD(P)H diaphorase histochemical localization method in (i)individual cells of the normal colonic mucosa (n = 13) whichserved as control, (ii) colonic polyps (n = 14), (iii) coloniccarcinoma (n = 20) and (iv) peritumoral mucosa (2 and 5 or 10cm away from the tumor). Four of the tumor specimens had normalepithelium adjacent to the cancer, which thus served as an internalcontrol. The expression of NOS activity in colon cancer wassignificantly reduced as compared to the control group of individuals(P < 0.004); undetectable in 25%, diminished in 45%, normalin 30%. On comparing the expression in normal mucosa and polypsthere was a significant reduction of the expression in polyps(P < 0.027); undetectable in 14%, reduced in 35%, normalin 51%. When compared to the peritumoral mucosa at 2 and 10cm the tumor showed a significant reduction in expression ofNOS activity (P < 0.001 and P < 0.0001 respectively).There was no significant difference seen in the expression at2 and 10 cm (P = 0.329). The peritumoral mucosa at a distanceof 2 cm away from the tumor when compared to the control mucosashowed no significant difference (P = 1.000), although thereis a tendency to a high normal expression of NOS activity inthe mucosa at a distance of 2 cm. Similarly, there was no significantdifference between the control mucosa and the peritumoral mucosaobtained at a distance of 10 cm (P = 0.383). The expressionof NOS activity in all tissues examined was abolished by preincubationof tissue with the selective NOS inhibitor L–NMMA butnot with D–NMMA. Our data showed extensive and significantreduction as identified by the NAD(P)H diaphorase method inthe expression of NOS activity, thereby reflecting the activityof nitric oxide in colon cancer and colonic polyps. The generalizedsuppression of this activity, which precedes the onset of overtneoplasia, may be an important event in colon carcinogenesis.This aberrant expression could also be compatible with the selectiveadvantage to either tumor promotion and metastatic progressionor to tumoricidal activity.     

A lithium chloride-extracted, broad-spectrum-adhesive 42-kilodalton protein of Staphylococcus epidermidis is ornithine carbamoyltransferase

To identify novel putative staphylococcal adhesins, lithium chloride extraction (an established method for selective surface molecule solubilization) was employed. N-terminal sequencing and functional assays identified a 42-kDa fibronectin-binding protein from Staphylococcus epidermidis as ornithine carbamoyltransferase (OCTase). However, OCTase was not recognizable extracellularly, and this fact together with the fact that LiCl induced DNA release and a decrease in viability suggests that LiCl extraction may not be the method of choice for selective surface molecule extraction from staphylococci.     

Perinatal mortality at a tertiary care hospital in punjab

The present report is a comparative analysis of perinatal mortality rate (PNMR) over two different periods of seven years each viz. 1982–1983 and 1989–1995. Data of at) the perinatal deaths in babies born at Christian Medical College and Hospital, Ludhiana from January 1989 to December 1995 was collected. The cause of death was ascertained by a detailed history, clinical examination and whenever possible, by autopsy and analysed by modified Wigglesworth’s classification. The PNMR during both the study periods was exactly the same i.e. 74/1000. There was a significant decline in the early neonatal mortality rate from 32/1000 to 25/1000. This was mainly due to improved survival of preterms as there were better life support measures available in the latter part of study period. In contrast, the still birth rate increased significantly from 42/1000 to 49/1000, thus neutralizing the fall of neonatal mortality. There was no change in the pattern of causes of death. Macerated still births occurring mainly in growth retarded babies and asphyxia remained the major causes of death. Mere provision of health services is not going to decrease PNMR. There is a need to educate ‘the ultimate’ consumers i.e. the women, for better utilization of these services. There is also an urgent need to sensitize and involve the medical practitioners imparting obstetrical services for solving these issues.     

Nonimmune interaction of the SfbI protein of Streptococcus pyogenes with the immunoglobulin G F(ab')(2) fragment

Fibronectin-binding protein I (SfbI) of Streptococcus pyogenes binds to mouse immunoglobulin G (IgG) but not to IgA or IgM in a nonimmune fashion. The fibronectin-binding domains of SfbI were responsible for this activity, which was targeted to the IgG F(ab')(2) fragment. SfbI also binds to B cells but not to CD4(+) or CD8(+) lymphocytes.     

Palytoxin both induces and inhibits the release of histamine from rat mast cells

Palytoxin (PTX) is a potent releaser of histamine from rat mast cells. The concentration response curve is bell-shaped with its range between 0.05 ng/ml and 5 micrograms/ml and its maximum at 50 ng/ml. The release of histamine by PTX is specific because (a) heat-inactivated (50 degrees C) mast cells are insensitive to PTX, and (b) extracellular calcium is essential. Removal of extracellular potassium as well as the presence of borate shifts the curve to the left by factor of 10. At higher concentrations (5 micrograms/ml), PTX inhibits the release of histamine due to compound 48/80, MCD-peptide, Con-A, ionophore A-23187, and PTX itself.     

Rapid identification of viridans streptococci by mass spectrometric discrimination

Viridans streptococci (VS) are responsible for several systemic diseases, such as endocarditis, abscesses, and septicemia. Unfortunately, species identification by conventional methods seems to be more difficult than species identification of other groups of bacteria. The aim of the present study was to evaluate the use of cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the rapid identification of 10 different species of VS. A total of 99 VS clinical isolates, 10 reference strains, and 20 strains from our in-house culture collection were analyzed by MALDI-TOF-MS. To evaluate the mass-spectrometric discrimination results, all strains were identified in parallel by phenotypic and genotypic methods. MALDI-TOF-MS identified 71 isolates as the mitis group, 23 as the anginosus group, and 5 as Streptococcus salivarius. Comparison of the species identification results obtained by the MALDI-TOF-MS analyses and with the phenotypic/genotypic identification systems showed 100% consistency at the species level. Thus, MALDI-TOF-MS seems to be a rapid and reliable method for the identification of species of VS from clinical samples.     

Utility of Indian adaptation of Integrated Management of Childhood Illness (IMCI) algorithm

Objective  To evaluate the utility of Indian adaptation of IMCI algorithm. Methods  Children presenting to outpatient department (n=169) or casualty (n=140) among 309 cases were assessed and classified as per IMCI algorithm, the final diagnosis made after detailed evaluation and relevant investigations, served as the gold standard. The diagnostic and therapeutic agreements between the gold standard, IMCI and vertical (on the basis of primary presenting complaint) algorithms were computed. Results  Coexistence of illness was observed in 75% of children as per IMCI algorithm. The mean (SD) number of morbidities as per the Gold standard and IMCI were 1.75 ± 0.75 and 2.19 ± 0.96 respectively. The referral criteria proved useful in predicting hospitalisation with high sensitivity and specificity (99.3% & 97.3%). IMCI algorithm covered majority of recorded illnesses. A total agreement with IMCI was found in 88.4% cases, while total disagreement was seen in 34.5% cases. Corresponding figures for vertical program were 88% and 18.6%. The difference was primarily due to underdiagnosis. The diagnostic discordance of IMCI and gold standard was evident for the cough category due to underdiagnosis of bronchial asthma and bronchiolitis and an overdiagnosis of pneumonia. The IMCI algorithm had a provision for preventive services of immunization (24.5% possibility of availing missed opportunity) and feeding advice. Conclusions  There is a sound scientific basis for adopting the IMCI approach since: (1) Co-existence of morbidities is a rule rather than exception for sick under-five children. (2) The algorithm provides good sensitivity and specificity for assessing severe illness and (3) IMCI algorithm is superior to vertical disease specific programs. It is, however, important to carefully adapt the generic IMCI algorithm to reflect the local morbidity profile.