Modelling the potential impact of adherence technologies on tuberculosis in India

BACKGROUND: For patients taking standard first-line tuberculosis treatment, missing 10% or more of their doses increases the risk of relapse six-fold. Digital technologies offer new approaches to adherence support for TB patients. We estimated the potential impact of new adherence technologies in India.METHOD: We developed a mathematical model of TB transmission dynamics in India, capturing the independent effects of missed doses and treatment default on post-treatment recurrence. We simulated the impact of interventions to address both missed doses and treatment default in the public and private healthcare sector.RESULTS: Adherence interventions, if deployed optimally in the public sector alone, would reduce cumulative TB incidence by 7.3% (95% credible intervals [CrI] 4.7-11) between 2020 and 2030, and by 16% (95% CrI 11-23) if also deployed in the private sector. This impact is roughly proportional to the effectiveness of the interventions. Reducing missed doses reduced incidence by 12% (95% CrI 7.0-18), while reducing treatment default reduced incidence by 7.9% (95% CrI 3.2-13).CONCLUSION: Minimising missed doses is at least as important as promoting treatment completion. Our results suggest that emerging technologies to improve treatment adherence could have a substantial impact on TB incidence and mortality in India.

Tuberculosis infection control measures at health care facilities offering HIV and tuberculosis services in India: A baseline assessment

BACKGROUND

Tuberculosis (TB) is one of world's oldest infectious disease and ranks alongside HIV as leading infectious killer. Tuberculosis infection control especially in HIV and TB care facilities has warranted attention after the recent health care-associated outbreaks in South Africa. The aim of this study was to describe the tuberculosis infection control measures implemented by HIV and TB care facilities in five high HIV burden provinces in India.

METHODS

Baseline assessment of 30 high burden Antiretroviral centers and TB facilities was conducted during Oct 2015-Dec 2015 by AIC trained staff using a structured format.

RESULTS

Thirty HIV and TB care facilities in five high HIV burden provinces were enrolled. Facility infrastructure and airborne infection control practices were highly varied between facilities. TB screening and fast tracking at ART centers is happening at majority of centers however inadequate TB infection control training, poor compliance to administrative and personal protective measures and lack of mechanism for health care workers surveillance need attention.

CONCLUSIONS

Local specific TB infection control interventions to be designed and implemented at HIV and TB care facilities including implementation of administrative, environmental and use of personal protective equipment's with the training of staff members. Health care workers surveillance needs to be prioritized considering the rising instances of tuberculosis among Health care workers.

Ras and C-Myc Oncoproteins during Tumor Progression in the Uterine Cervix

Aims and background

Altered oncogenic activity is a feature associated with many malignant and premalignant conditions. Among the many oncogenes, ras and myc are commonly altered in many tumors. This study aims to evaluate the expression of ras and c-myc oncoproteins in a total of 204 cervical tissue samples, including premalignant and malignant lesions as well as apparently normal cervical tissue.

Methods and study design

Mouse monoclonal antibodies against the three mammalian ras gene products (c-H-ras, c-K-ras, c-N-ras) and the c-myc protein were used to evaluate oncoprotein expression by immunocytochemistry.

Results

None of the samples analyzed displayed immunoreactivity for H-ras and K-ras. Normal cervical epithelium showed minimal immunoreactivity for N-ras with about 33% of the samples expressing the protein. More conspicuous expression in normal tissue was displayed by c-myc, with about 90% of the samples expressing the protein (mean value of cells positive = 34%). The immunoreactivity for N-ras increased with increasing histological abnormality from low-grade squamous intraepithelial lesions (SIL) to invasive carcinoma. Increased immunoreactivity for N-ras was evident in the basaloid cells of malignant lesions, with the maximum value of 66% found in poorly differentiated squamous cell carcinoma (PDSCC). The percentage of nuclei positive for c-myc also showed a gradual increase from low-grade SIL onwards, the highest positivity being found in PDSCC, where the mean value was 85%. Statistical analysis revealed a good correlation between the expression of N-ras (r = 0.8922, P = 0.001) and c-myc (r = 0.8856, P =0.001) and various histological stages of tumor progression in the cervical epithelium.

Conclusions

These results therefore suggest that c-myc and N-ras oncoproteins are important during tumor progression in the uterine cervix.

Bottom-up or top-down: unit cost estimation of tuberculosis diagnostic tests in India

SETTING

Of 18 sites that participated in an implementation study of the Xpert® MTB/RIF assay in India, we selected five microscopy centres and two reference laboratories.

OBJECTIVE

To obtain unit costs of diagnostic tests for tuberculosis (TB) and drug-resistant TB.

DESIGN

Laboratories were purposely selected to capture regional variations and different laboratory types. Both bottom-up and the top-down methods were used to estimate unit costs.

RESULTS

At the microscopy centres, mean bottom-up unit costs were respectively US$0.83 (range US$0.60-US$1.10) and US$12.29 (US$11.61-US$12.89) for sputum smear microscopy and Xpert. At the reference laboratories, mean unit costs were US$1.69 for the decontamination procedure, US$9.83 for a solid culture, US$11.06 for a liquid culture, US$29.88 for a drug susceptibility test, and US$18.18 for a line-probe assay. Top-down mean unit cost estimates were higher for all tests, and for sputum smear microscopy and Xpert these increased to respectively US$1.51 and US$13.58. The difference between bottom-up and top-down estimates was greatest for tests performed at the reference laboratories.

CONCLUSION

These unit costs for TB diagnostics can be used to estimate resource requirements and cost-effectiveness in India, taking into account geographical location, laboratory type and capacity utilisation.

Unfavourable outcomes among patients with MDR-TB on the standard 24-month regimen in Maharashtra, India

Setting: Patients with multidrug-resistant tuberculosis (MDR-TB) registered for treatment (2011-2012 cohort) using the standard 24-month regimen, under the Revised National TB Control Programme's programmatic management of drug-resistant TB (PMDT), Maharashtra, India. Objectives: To assess the treatment outcomes and the timing and risk factors for unfavourable treatment outcomes, with a focus on death and loss to follow-up (LTFU). Method: This was a retrospective cohort study involving a review of PMDT records. Treatment outcomes were reported on 31 December 2014. Results: Of 4024 patients, treatment success was recorded in 1168 (29%). Unfavourable outcomes occurred in 2242 (56%), of whom 857 (21%) died and 768 (19%) were lost to follow-up. Treatment outcomes were missing on record review for 375 (9%) patients, and 239 (6%) were still undergoing treatment. Half of LTFU occurred within 3 months, and more than four fifths of deaths occurred after 6 months of treatment. Human immunodeficiency virus infection, being underweight, age ⩾ 15 years, male sex and pulmonary TB were the main risk factors for death, LTFU or other unfavourable treatment outcomes. Conclusion: The study found poor treatment outcomes in patients with MDR-TB registered for treatment in Maharashtra, India. Interventions are required to address the high rates of LTFU and death.

Integration and decentralisation of TB-HIV services increases HIV testing of TB cases in Rajasthan, India

The proportion of tuberculosis (TB) patients tested for the human immunodeficiency virus (HIV) in the state of Ra-jasthan, India, is limited by the availability of HIV testing facilities. Rajasthan implemented a policy of initiating TB-HIV diagnosis at all health institutions in July 2013. The number of TB diagnostic facilities increased from 33 to 63 in Banswara District and from 22 to 68 in Jhunjhunu District, while the number of HIV testing facilities in these districts increased from 1 to 53 and from 10 to 81, respectively, after the policy implementation. The proportion of TB patients tested for HIV increased by respectively 27% and 19%.

What a difference a day makes: same-day vs. 2-day sputum smear microscopy for diagnosing tuberculosis

Setting: Nine district-level microscopy centres in Assam and Tripura, India. Objective: Same-day sputum microscopy is now recommended for tuberculosis (TB) diagnosis. We compared this method against the conventional 2-day approach in routine programmatic settings. Methods: During October-December 2012, all adult presumptive TB patients were requested to provide three sputum samples (one at the initial visit, the second 1 h after the first sample, and the third the next morning) for examination by Ziehl-Neelsen smear microscopy. Detection of acid-fast bacilli with any sample was diagnostic. The first and second spot sample comprised the same-day approach, and the first spot sample and next-day sample comprised the 2-day approach. Results: Of 2168 presumptive TB patients, 403 (18.6%) were smear-positive according to the same-day method compared to 427 (19.7%) by the 2-day method (McNemar's test, P < 0.001). Of the total 429 TB patients, 26 (6.1%) were missed by the same-day method and 2 (0.5%) by the 2-day method. Conclusion: Same-day specimen collection for microscopy missed more TB than 2-day collection. In India, missing cases by using same-day microscopy would translate into a considerable absolute number, hindering TB control efforts. We question the indiscriminate switch to same-day diagnosis in settings where patients reliably return for testing the next day.

LED fluorescence microscopy increases the detection of smear-positive pulmonary tuberculosis in medical colleges of India

In July 2012, light-emitting diode fluorescence microscopy (LED-FM) replaced conventional light microscopy using Ziehl-Neelsen stain in the detection of sputum-positive pulmonary tuberculosis in 190 microscopy centres of medical colleges operating under India's Revised National Tuberculosis Control Programme. We compared the performance of LED-FM (July-December 2012) to that of conventional microscopy (July-December 2011) across 190 sites. Of 222 658 patients examined using conventional microscopy, 28 042 (12.6%) were smear-positive, while of 224 714 examined using LED-FM, 33 552 (14.9%) were smear-positive, an additional yield of 5251 cases after adjusting for the increase in patients examined. We recommend replacing conventional microscopy with LED-FM in high workload microscopy centres in India.

Same-day light-emitting diode fluorescence microscopy for the diagnosis of tuberculosis in Chhattisgarh, India

SETTING

Three medical college hospitals using light-emitting diode fluorescence microscopy (LED-FM) for diagnosing tuberculosis (TB) in Chhattisgarh, India.

OBJECTIVES

To assess and compare the proportion of sputum smear-positive TB patients diagnosed through same-day microscopy (spot-spot) strategy or with the conventional (spot-morning) strategy.

METHODS

During November 2012 - March 2013, all consecutively enrolled presumptive TB patients (aged ≥ 18 years) were requested to provide three specimens: two spot specimens collected 1 h apart on the first day and one early morning specimen the next day; these were stained using auramine-O and examined using LED-FM.

RESULTS

Of 1716 (93% of total 1845) presumptive TB patients who provided all three specimens, 218 (13%) were smear-positive: 200 (11.7%) by same-day microscopy and 217 (12.7%) by the conventional method (McNemar's χ(2) 13.5, df 1, P = 0.0002). Eighteen (8.3%) cases were missed by the same-day method.

CONCLUSION

Although LED-FM is more sensitive to paucibacillary samples, 8% of smear-positive cases were missed using the same-day method. These findings indicate the need to revisit the global applicability of the current World Health Organization recommendation of switching to same-day diagnosis from the conventional policy.

Isoniazid preventive treatment in children in two districts of South India: does practice follow policy?

SETTING

Two districts of Tamil Nadu, India

OBJECTIVES

To determine the proportion of household contacts aged <6 years of patients with tuberculosis (TB) with positive sputum microscopy results who initiated and completed isoniazid preventive treatment (IPT), and to determine reasons for non-initiation and non-completion of IPT.

DESIGN

Household visits were conducted on a random sample of adult patients registered during January-June 2012 to identify household contacts aged <6 years.

RESULTS

Among 271 children living with 691 index patients, 218 (80%) were evaluated and 9 (4%) were diagnosed with TB. Of 209 remaining contacts, 70 (33%) started IPT and 16 (22.9%) completed a full course of IPT. Of 139 contacts who did not start IPT, five developed TB disease. Reasons for non-initiation of IPT included no home visit by the field staff (19%) and no education about IPT (61%). Reasons for non-completion included isoniazid not provided (52%) and long duration of treatment (28%).

CONCLUSION

This study shows that Revised National TB Programme guidance was not being followed and IPT implementation was poor. Poor IPT uptake represents a missed opportunity to prevent future TB cases. Provision of IPT may be improved through training, improved logistics and enhanced supervision and monitoring.

Health-care seeking among people with cough of 2 weeks or more in India. Is passive TB case finding sufficient?

SETTING

Thirty districts of India.

OBJECTIVES

To estimate 1) the proportion of people with cough of ≥2 weeks, 2) those who did not seek care from a health care provider for cough, and 3) their characteristics.

METHODOLOGY

A cross-sectional community-based survey in which 4562 people (aged ≥18 years) were interviewed.

RESULTS

Of the 4562 individuals interviewed, 437 (9.5%, 95%CI 7.2-11.8) had cough ≥2 weeks; this was more frequent in those >55 years of age (14%) and in those from districts in eastern (12%) and northern (11%) states of India. Of those with cough, 300 (69%, 95%CI 60-77) had not sought care from any health care provider. Not seeking care was more frequent in people residing in rural areas (73%) compared with urban areas (53%), and in the districts of eastern (82%) and northern (74%) states compared to districts from the southern (46%) and western (54%) states.

CONCLUSIONS

Nearly a tenth of those interviewed aged ≥18 years had cough of ≥2 weeks. About two thirds, especially those from rural areas, had not visited a health care provider for the cough. This finding has huge implications for India's current mostly passive case-finding strategy for detecting and controlling tuberculosis.

Antichymotrypsin interaction with chymotrypsin. Reactions following encounter complex formation

Serpins, serine proteinase inhibitors, form enzymatically inactive, 1:1 complexes (denoted E*I*) with their target proteinases, that only slowly release I*, in which the P1-P1' linkage is cleaved. Recently we presented evidence that the serpin antichymotrypsin (ACT, I) reacts with the serine proteinase chymotrypsin (Chtr, E) to form an E*I* complex via a three-step mechanism, E + I <==> E .I <==> EI' <==> E*I* in which EI', which retains the P1-P1' linkage, is formed in a partly or largely rate-determining step, depending on temperature (O'Malley, K. H, Nair, S. A., Rubin, H., and Cooperman, B. S. (1997) J. Biol. Chem. 272, 5354-5359). Here we extend these studies through the introduction of a new assay for the formation of the postcomplex fragment, corresponding to ACT residues 359 (the P1' residue) to 398 (the C terminus), coupled with rapid quench flow kinetic analysis. We show that the E.I encounter complex of wild type-rACT and Chtr forms both E*I* and postcomplex fragment with the same rate constant, so that both species arise from EI' conversion to E*I*. These results support our earlier conclusion that the P1-P1' linkage is preserved in EI' and imply that E*I* corresponds to a covalent adduct of E and I, either acyl enzyme or the tetrahedral intermediate formed by water attack on acyl enzyme. Furthermore, we show that the A347R (P12) variant of rACT, which is a substrate rather than an inhibitor of Chtr, has a rate constant for postcomplex fragment formation from the E.I complex very similar to that observed for WT-rACT, implying that EI' is the common intermediate from which partitioning to inhibitor and substrate pathways occurs. These results are used to elaborate a proposed scheme for ACT interaction with Chtr that is considered in the light of relevant results from studies of other serpin-serine proteinase pairs.

The design, synthesis and activity of pentapeptide pp60c-src inhibitors containing L-phosphotyrosine mimics

Efficient syntheses of 4-(R,S-hydroxyphosphonomethyl)-L-phenylalanine and 4-carboxy-L-phenylalanine within the context of the pentapeptide Ac-Ile-X-Gly-Glu-Phe-NH2 (wherein X = the unnatural amino acid) illustrate the use of a divergent synthetic strategy from an advanced common peptide intermediate to more readily access peptide-based tyrosine kinase inhibitors. The key intermediate, Ac-Ile-Phe(4-formyl)-Gly-Glu(O-tBu)-Phe-NH2, was synthesized by a facile palladium-catalyzed carbonylation of Ac-Ile-Phe(4-iodo)-Gly-Glu(O-tBu)-Phe-NH2. Oxidation of Ac-Ile-Phe(4-formyl)-Gly-Glu(O-tBu)-Phe-NH2 with tetrabutylammonium permanganate or addition of di-t-butylphosphite, both followed by trifluoroacetic acid deprotection, gave the target pentapeptide inhibitors wherein X = 4-carboxy-L-phenylalanine or 4-(R,S-hydroxyphosphonomethyl)-L-phenylalanine, respectively. These two peptides gave somewhat more potent inhibition of the tyrosine kinase pp60c-src than the corresponding pentapeptide wherein X = L-phenylalanine, demonstrating that appended functionalities at the 4-position are accepted and can enhance binding through added interactions within the catalytic region of the active site.

Cytokeratins and the evaluation of tumor differentiation in squamous lesions of the uterine cervix

The differential expression of cytokeratins in epithelial or squamous cells has been demonstrated to be altered during the process of carcinogenesis. This altered expression of cytokeratins (CKs) may be closely related with epithelial differentiation and may remain stable in malignant tumors. In the present study an analysis using two monoclonal antibodies, CK 8.12 antibody specific for CK type 13 and 16 and CK 8.60 antibody specific for CK type 1, 10 and 11 was done in different grades of lesions in the uterine cervix. Changes from the normal expression pattern were seen in high grade Squamous intraepithelial lesions (SIL) (CIN-2/3) and invasive squamous cell carcinoma (SCC). No conspicuous difference in the staining expression between normal/benign cervical tissue and low grade SIL (CIN-I) was evident. Statistical analysis also revealed a significant correlation between the expression of these CK types to the differentiation status of the cervical lesions analyzed. Alterations in the expression of these CKs can be correlated to the differentiation pathway which may be deregulated during cervical carcinogenesis. The findings of the present study suggest that the expression of CK types 13 and 16 and 1, 10 and 11 using CK 8.12 and CK 8.60 antibodies respectively may serve as markers of differentiation in cervical squamous neoplasms.

The basement membrane and tumor progression in the uterine cervix

Immunocytochemical localization of the basement membrane (BM) proteins laminin, type-IV collagen and fibronectin were analyzed in normal cervical epithelium, low grade squamous intraepithelial lesions (SILs), high grade SILs and invasive squamous cell carcinoma (SCC) of the uterine cervix. A regular, thick and continuous BM was present in normal cervical epithelium and low grade SIL. Interruptions and discontinuity of the BM were more evident in high grade SILs. There was a good correlation between increasing severity of the lesion and increasing number of breaks. In SCC, the distribution of laminin, collagen IV and fibronectin was related to the degree of cellular differentiation, with decreased immunoreactivity being evident in moderately and poorly differentiated tumors. As the invasive potential of the tumor increased, the fragmentation and loss of BM was more evident. Fibronectin showed only moderate to mild immunoreactivity in normal cervical epithelium and low grade SILs. However, the intensity of expression increased in high grade SILs especially in the peritumoral stroma. It may therefore be concluded from these results that snythesis and reabsorption of BM proteins may be related to shifts in cellular metabolism during tumorigenesis.

The kinetic mechanism of serpin-proteinase complex formation. An intermediate between the michaelis complex and the inhibited complex

Serine proteinase inhibitors (serpins) form enzymatically inactive, 1:1 complexes (denoted E*I*) with their target proteinases that release free enzyme and cleaved inhibitor only very slowly. The mechanism of E*I* formation is incompletely understood and continues to be a source of controversy. Kinetic evidence exists that formation of E*I* proceeds via a Michaelis complex (E.I) and so involves at least two steps. In this paper, we determine the rate of E*I* formation from alpha-chymotrypsin and alpha1-antichymotrypsin using two approaches: first, by stopped-flow spectrofluorometric monitoring of the fluorescent change resulting from reaction of alpha-chymotrypsin with a fluorescent derivative of alpha1-antichymotrypsin (derivatized at position P7 of the reactive center loop); and second, by a rapid mixing/quench approach and SDS-polyacrylamide gel electrophoresis analysis. In some cases, serpins are both substrates and inhibitors of the same enzyme. Our results indicate the presence of an intermediate between E.I and E*I* and suggest that the partitioning step between inhibitor and substrate pathways precedes P1-P1' cleavage.

Increased expression of cytokeratins 14, 18 and 19 correlates with tumor progression in the uterine cervix

The expression of cytokeratins (CKs) in normal cervical epithelium, low grade squamous intraepithelial lesions (SIL), high grade SILs and squamous cell carcinoma (SCC) were analyzed using four different monoclonal antikeratin antibodies. In normal cervical epithelium, CK 18 showed strong immunoreactivity in basal and parabasal layers. CK 19 and 14 were expressed only in the basal layer while CK 13 was found selectively n the spinal cells. As the lesions progressed from low grade SIL to high grade SIL, immunoreactivity of CK 18, 19 and 14 in the basal cell compartment increased while the expression of CK 13 decreased. In SCC, as well-differentiated tumors showed decreased immunoreactivity for CK 18, 19 and 14 with CK 13 showing a strong and focal (localized) immunoreactivity. Undifferentiated carcinomas totally lacked CK 13 reactivity. Our findings therefore suggest that expression of CK 18, 19 and 14 may be directly related to tumor grade and CK 13 may be a marker of differentiation in cervical lesions.

The effect of epidural fentanyl on the minimum local analgesic concentration of epidural chloroprocaine in labor

The minimum local analgesic concentration (MLAC) has been defined as the median effective local analgesic concentration (EC50) in a 20-mL volume in the first stage of labor. The aim of this study was to determine the local anesthetic sparing efficacy of epidural fentanyl by its effect on the MLAC of chloroprocaine. Fifty-six parturients, not exceeding 7 cm cervical dilation, who requested epidural analgesia were allocated to one of two groups in this double-blind, randomized, prospective study. After placing a lumbar epidural catheter, 20 mL of the solution being tested was given: chloroprocaine (n = 28) or chloroprocaine with fentanyl 3 micrograms/mL (60 micrograms) (n = 28). The concentration of chloroprocaine was determined by the response of the previous patient to a higher or lower concentration using up-down sequential allocation. Analgesic efficacy was assessed using 100-mm visual analog pain scores with 10 mm or less within 30 min defined as effective. The MLAC of chloroprocaine was reduced from 0.43% wt/vol to 0.26% wt/vol by fentanyl (P = 0.023). Thus, the addition of epidural fentanyl 3 micrograms/mL (60 micrograms resulted in a significant 40% reduction in the MLAC of chloroprocaine in the first stage of labor.

Involucrin and tumor progression in the uterine cervix

The expression of involucrin, a cytoplasmic protein synthesized during squamous maturation, was assessed by immunocytochemistry in different grades of cervical lesions. In normal/benign cervical epithelium and low-grade squamous intraepithelial lesions [SILS or cervical intraepithelial neoplasia (CIN)-1] involucrin showed intense and homogenous cytoplasmic expression in the spinal layers of 75 and 57% of samples, respectively. The basal cell layers showed no expression of involucrin. In high-grade SILs (CIN-2/3) 40% of the samples showed diffuse and focal cytoplasmic expression of involucrin in the differentiated basaloid cells. In the squamous cell carcinomas (SCCs) analyzed, well-differentiated tumors showed intense focal expression in 61% of the cases, moderately differentiated SCCs showed intense expression in 33% of the cases, while poorly differentiated SCCs (PDSCC) showed only a mild focal expression in 7% of cases. With increasing severity of the lesions, patchy expression of involucrin with a mixture of reactive and nonreactive cells predominated. Patterns of immunocytochemical staining for involucrin in cervical lesions of different grades, from low-grade to high-grade SILs, and invasive carcinoma may be of critical importance, if loss of involucrin expression is used as a criterion for neoplastic transformation in cervical epithelium. Our findings suggest that involucrin may be a sensitive marker in identifying the differentiation status of the lesion while the absence of involucrin in PDSCC may be helpful in differential diagnosis.

Identification of efficient pentapeptide substrates for the tyrosine kinase pp60c-src

The development of inhibitors of protein tyrosine kinases (PTKs) is a promising approach to obtaining new therapeutic agents for a variety of diseases, particularly cancer. However, the discovery of peptide-based inhibitors has been hindered by the lack of small peptide substrate sequences (i.e. five residues or less) with which a variety of inhibitor designs could be readily evaluated by replacing the Tyr with natural and unnatural amino acids. These prototypical small peptide inhibitors could then form the basis for designing analogous conformationally constrained, peptide-mimetic or non-peptide inhibitors with improved therapeutic potential. In this study we have identified the best known small peptide substrate for the PTK pp60c-src, which is the parent of the src family of nonreceptor PTKs. This pentapeptide substrate, Ac-Ile-Tyr-Gly-Glu-Phe-NH2, has a Km of 368 microM and Vmax of 1.02 mumol/min/mg when tested utilizing the assay methodology of Budde et al. (Anal. Biochem. 1992, 200, 347-351) after a series of modifications were made to more closely simulate the conditions inside a typical mammalian cell. This substrate was designed from information obtained by Songyang et al. (Nature 1995, 373, 536-539) with a 2.5 billion member combinatorial library of peptide substrates for pp60c-src. A second pentapeptide substrate, Ac-Glu-Asp-Ala-Ile-Tyr-NH2, with a weaker binding affinity (Km = 880 microM) but improved Vmax (1.86 mumol/min/mg), was also identified. This peptide was designed from the pp60c-src autophosphorylation sequence and information obtained by Songyang et al. (Ibid.) and Till et al. (J. Biol. Chem. 1994, 269, 7423-7428) with combinatorial libraries of peptide substrates. These new substrates provide sufficient binding affinities and rates of phosphorylation to be utilized for evaluating the relative effectiveness of various reversible and mechanism-based irreversible inhibitor designs for pp60c-src while appended to easily prepared small peptides.

Argyrophilic nucleolar organizer regions (AgNORs) in inflammatory pre-malignant and malignant lesions of the uterine cervix

Nuclear organizer regions (NORs) code for ribosomal RNA and are associated with non-histone nucleoproteins, which can be identified by silver staining (AgNORs). AgNORs have been correlated to proliferative activity of tumors and hence may be prognosis-related. The present study evaluates AgNOR counts in inflammatory lesions of the uterine cervix, cervical intra-epithelial neoplasia, and invasive cervical squamous carcinoma. Significant variation in AgNOR counts were observed between the three study groups, with invasive carcinoma showing maximum counts. Further, a highly significant positive correlation was observed between AgNOR counts and tumor progression. These results therefore suggest that AgNOR counts may be of significance in the evaluation of cervical carcinogenesis and could elaborate histopathological diagnosis of cervical lesions.

Oral cancer and human papillomaviruses: is there a link?

Cancer of the oral cavity accounts for almost 56,000 new cases in India each year totalling almost 30% of all cancer cases in the country. Despite the numerous advances in etiology and epidemiology, the mechanisms involved in oral carcinogenesis remain obscure. Current research has provided some provocative results, suggesting an association between human papillomavirus (HPV) and development of squamous cell tumors including oral cancer. Evidence has been presented showing HPV infection of the oral mucosa and its relation to neoplastic changes. However a clear cut association as is evident in the uterine cervix is not yet available. However, considering the many similarities between oral and cervical oncogenesis, many of the HPV induced changes in the cervix may also be applicable to the oral mucosa. This paper studies the evidence for the possible role of HPV infection in oral carcinogenesis, the uterine cervix as a model for HPV mediated carcinogenesis, and tries to determine if similar mechanisms could exist in both cases.