Evaluation of telomerase activation in head and neck cancer

During replication of the linear chromosomes, telomeres, i.e. the ends of the chromosomes, are not replicated completely by the conventional DNA polymerases. Therefore, normal somatic cells senesce after certain number of cell divisions. Telomerase is a special reverse transcriptase used by most eukaryotes to achieve immortalization. Telomerase activity has been determined in a variety of cancers. However, there are few reports on telomerase activity in head and neck cancer. The etiology of the disease in India is completely different from Western countries. Tobacco consumption is more prevalent in India and the mode of tobacco consumption (e.g. chewing, snuffing, bidi smoking, reverse smoking) is also different. The present study determined telomerase activity in 32 malignant tumour samples of head and neck cancer patients, 11 samples from patients with precancerous/benign lesions and 30 samples of adjacent normal tissues. Telomerase was found to be activated in 80% of the patients with head and neck cancer, 100% of the patients with precancerous/benign lesions and 74% of the adjacent normal tissues. According to the theory of field cancerization, carcinogenic insults (e.g. tobacco) may result into multiple malignant foci. This fact may explain the reason for high telomerase positivity in adjacent normal as well as precancerous/benign tissues. Telomerase activation and the clinical or histopathological characteristics of the head and neck cancer patients were observed to be independent features. This is a preliminary report which has generated a greater interest for in-depth elucidation of the role of telomerase and telomeres in head and neck carcinogenesis in India.

Evaluation of glycoprotein constituents in head and neck cancer patients undergoing radiotherapy

BACKGROUND

Alterations in serum levels of several glycoprotein constituents are reported to be useful for treatment monitoring of cancer patients. The purpose of this study was to determine efficacy of sialic acid and seromucoid fraction as treatment monitors for head and neck (H&N) cancer patients undergoing radiotherapy (RT).

METHODS

Serum levels of total sialic acid (TSA), lipid-bound sialic acid (LSA), and seromucoid fraction (measured as Mucoid protein [MP] and hexose) were studied in age matched controls and in patients with H&N cancer at diagnosis and during/after completion of RT. The markers were estimated by spectrophotometric methods.

RESULTS

Serum levels of sialic acid forms and seromucoid fraction were significantly elevated (p<.001) in untreated H&N cancer patients (n = 32) as compared with controls (n = 50). The marker levels were significantly declined (p<.001) in H&N cancer patients who responded to RT as compared with their levels at diagnosis, whereas the levels were persistently elevated in nonresponders.

CONCLUSION

Evaluation of sialic acid forms and seromucoid fraction could be used for monitoring the treatment of H&N cancer patients undergoing RT.

Seromucoid fraction: a useful biomarker for patients with breast cancer

Seromucoid fraction was measured in terms of mucoid proteins (MP) and hexose content from sera of 1) 47 healthy women, 2) 48 women who had benign breast diseases, 3) 151 untreated patients with breast cancer, and 4) 245 follow-up samples collected from the same breast cancer patients. Mucoid proteins and hexose levels were found to be significantly elevated in untreated patients with breast cancer when compared with the healthy participants (p < 0.001) and patients who had benign breast diseases (p < 0.02 and p < 0.05, respectively). Receiver operating characteristic (ROC) curve analysis revealed potential diagnostic application of both markers for breast cancer. A good correlation was observed between favorable treatment response and decline in serum-marker levels. The markers in patients who did not respond to anticancer therapy remained stable or increased during follow-up. These data indicate that seromucoid fraction can be an useful biochemical marker for breast cancer patients.

Glycoprotein electrophoretic pattern in sera of patients with oral precancerous conditions and upper aerodigestive tract cancer

Cancer of the upper aerodigestive tract is one of the leading sites of human malignancies in India. Various glycoproteins have been claimed to be specifically associated with cancer. Serum glycoprotein electrophoresis was carried out in sera obtained from 23 healthy individuals [10 without habit of tobacco consumption (NHT) 13 with habit of tobacco consumption (WHT)], 46 patients with oral precancerous conditions (OPC) and 110 untreated patients with upper aerodigestive tract cancer. Eighty-six samples from the cancer patients were also collected after initiation of anticancer therapy. The albumin, alpha, beta and gamma region glycoproteins were quantitated by densitometric scanning after separation by polyacrylamide disc gel (PADG) electrophoresis. Mean values of albumin and alpha region glycoproteins were significantly lower in WHT and patients with OPC as compared to NHT. The gamma region glycoproteins were significantly elevated in WHT, patients with OPC and untreated cancer patients as compared to the NHT. The albumin region glycoproteins were significantly low, whereas, gamma region glycoproteins were significantly elevated in nonresponders as compared to their pretreatment levels. The glycoprotein values in complete responders were comparable with NHT. An extra glycoprotein band was found in the post beta region, in most of the individuals (>50%) with habit of tobacco consumption in all the groups. There was a decrease in the albumin/gamma, alpha/gamma and beta/gamma values in patients with OPC as well as untreated cancer patients as compared to NHT. Albumin/gamma, alpha/gamma and beta/gamma values were lower in nonresponders as compared to their pretreatment value. The results indicate that the alterations in glycoprotein electrophoresis pattern may be useful for early detection of cancer of the upper aerodigestive tract. It may also be helpful in treatment monitoring of cancer patients.

Importance of glycoproteins in human cancer

Usefulness of cell surface glycoprotein components as markers in early detection of cancer and in monitoring progress during treatment has been evaluated. Total sialic acid (TSA), lipid bound sialic acid (LSA) and seromucoid fractions (SF) have been compared in the sera of healthy human volunteers and patients at different stages of diagnosis and treatment of leukemia, cancer of breast, cervix, and oral cavity. The levels of TSA, LSA and SF are found to be increased in cancer and is proportionate with malignancy. Their levels show decline in patients who respond well to treatment and show increase in patients with recurrence of cancer even before any clinical evidence of recurrence is available. Changes have also been noted in the glycoprotein fractions and their ratios.

Electrophoretic pattern of serum glycoproteins on polyacrylamide disc gel in patients with breast cancer

Numerous investigators have identified, isolated and characterized serum glycoproteins that are claimed to be specifically associated with malignancy. We have carried out serum glycoprotein electrophoresis on polyacrylamide disc gel in 53 breast cancer patients, at diagnosis as well as during and after therapy. Follow-up samples were divided into complete responders (CR) (n = 138) and nonresponders (NR) (n = 44). Glycoprotein electrophoresis showed multiple bands for each sample which were categorized into four groups: albumin, alpha, beta and gamma. The results revealed a decreasing number of CR and increasing number of NR with elevated (as compared to pretreatment levels) albumin fraction glycoproteins. Gamma region glycoproteins showed the reverse pattern to that of albumin region glycoproteins. The alpha and beta region glycoproteins revealed an increasing number of CR having higher values with increase in follow-up duration. In comparison with their pretreatment values CR showed significantly increased (Paired "t" test) values of albumin, alpha and beta region glycoproteins (p < 0.01, p < 0.001 and p < 0.001, respectively) and decreased gamma region glycoproteins (p < 0.001). The albumin, alpha, beta and gamma region glycoprotein levels were comparable between NR and untreated cancer patients. The variations in albumin, alpha, beta and gamma region glycoproteins correlate with treatment response, which might be useful in the treatment monitoring, and prediction of recurrence in breast cancer patients.

Type characterisation and antibiotic susceptibility of Burkholderia (Pseudomonas) cepacia isolates from patients with cystic fibrosis in the United Kingdom and the Republic of Ireland

The spread of Burkholderia cepacia among cystic fibrosis (CF) patients in the UK prompted an investigation into whether an epidemic strain was responsible. A total of 366 B. cepacia isolates from 178 CF patients in 17 centres was examined by ribotyping and pulsed-field gel electrophoresis (PFGE). Associations were also sought between antibiotic resistance and strain type. More than 50 ribotype patterns were found but one, termed ribotype 1, was identified from 68 patients in eight centres. One centre had a single patient with this type while, in others, most or all patients harboured this organism. Small clusters of apparent cross-colonisation within centres were also evident for some other ribotypes. PFGE confirmed that ribotype 1 isolates were genetically similar. Ribotype 1 isolates were not markedly more resistant to antimicrobial agents than were other isolates, and the MICs of individual antibiotics were no more tightly clustered for ribotype 1 isolates than for others. Most isolates were resistant to ciprofloxacin, amikacin, gentamicin, tobramycin, carbenicillin, cefuroxime, cefotaxime, imipenem, biapenem, chloramphenicol, tetracycline, trimethoprim and sulphamethoxazole, but > or = 77% were susceptible to ceftazidime, piperacillin, piperacillin/ tazobactam and meropenem. We conclude that numerous strains of B. cepacia colonise CF patients in the UK and Ireland but that one epidemic strain has spread in at least eight centres. Isolates of this strain appear homogenous in total genomic profile but very variable in antibiotic susceptibility.

Mutational analysis of the endothelin type A receptor (ETA): interactions and model of selective ETA antagonist BMS-182874 with putative ETA receptor binding cavity

Endothelin (ET) receptor antagonism is a potential therapeutic intervention in the treatment of vascular diseases. To elucidate the mechanism of antagonist-ET receptor complex formation, the interactions of four chemically distinct antagonists were investigated using a combination of genetic and biochemical approaches. By site-specific mutagenesis we previously demonstrated that Tyr129 in the second transmembrane domain was critical for high-affinity, subtype-selective binding to the A subtype of ET (ETA) receptors [Krystek et al. (1994) J. Biol. Chem. 269, 12383-12386]. Affinities of the constrained cyclic pentapeptide BQ-123, the pyrimidinylbenzenesulfonamide bosentan, the indancarboxlic acid SB 209670, and the naphthalenesulfonamide BMS-182874 were decreased 20-1000-fold in Tyr129Ala, Tyr129Ser, and Tyr129His ETA receptor mutants. Substitution of Tyr129 with Phe or Trp did not alter the high-affinity binding of BQ-123, bosentan, or SB 209670. BMS-182874 binding affinity was decreased 10-fold in Tyr129Phe and Tyr129trp ET receptors. These data indicate a role of aromatic interactions in the binding of these antagonists to ETA receptors an, in the case of BMS-182874, also suggested a hydrogen bond with the tyrosine hydroxyl. This hypothesis was supported by structure-activity data with analogs of BMS-182874 that varied the C-5 dimethylamino substituent on the naphthalene ring. Mutation of Asp126 and Asp133 also altered binding of BMS-182874 and C-5 analogs. In all cases, naphthalenesulfonamide binding was more severely affected by mutation of Asp133 than by mutation of Asp126. Phosphoinositide hydrolysis and extracellular acidification rate studies demonstrated the importance of Tyr129 to ETA-mediated signal transduction. On the basis of these data, two plausible models of the docked conformation of BMS-182874 in the ETA receptor are proposed as a starting point for further delineation of interactions that underlie antagonist-ETA receptor complex formation.

Bacillaene, a novel inhibitor of procaryotic protein synthesis produced by Bacillus subtilis: production, taxonomy, isolation, physico-chemical characterization and biological activity

Bacillaene, a novel polyene antibiotic, was discovered and isolated from fermentation broths of a strain of Bacillus subtilis. The novel antibiotic has a nominal molecular weight of 580 and an empirical formula of C35H48O7. Bacillaene is active against a broad spectrum of bacteria in agar-plate diffusion assays. Studies in vitro indicate that the antibiotic inhibits prokaryotic protein synthesis but not eukaryotic protein synthesis. Cell survival studies performed with strains of Escherichia coli indicate that the antibiotic is a bacteriostatic agent.

Aspartate mutation distinguishes ETA but not ETB receptor subtype-selective ligand binding while abolishing phospholipase C activation in both receptors

The endothelin receptors, ETA and ETB, are G protein-coupled receptors (GPCR) that show distinctively different binding profiles for the endothelin peptides and other ligands. We recently reported that Tyr129 in the second transmembrane region (TM2) of the ETA receptor was critical for subtype-specific ligand binding [Krystek, S.R. et al. (1994) J. Biol. Chem. 269, 12383-12386]. Receptor models indicated that aspartic acids located one helical turn above (Asp133) and below (Asp126) Tyr129 in ETA had their side chains directed toward the putative binding cavity. Similarly in ETB, Asp147 and Asp154 are located one turn below and above His150, the residue that corresponds to Tyr129. Asp126 in ETA and Asp147 in ETB correspond to the highly conserved aspartate present in TM2 of many GPCR that has frequently been shown to be crucial for agonist efficacy. Mutagenesis of Asp126 of the human ETA receptor to alanine resulted in an unaltered affinity for ET-1, a 160-fold increase in ET-3 affinity and a decrease in affinity for the ETA selective naphthalenesulfonamide, BMS-182874. ET-1 activation of phospholipase C was abolished. In addition, despite the gain in binding affinity, ET-3 failed to activate phospholipase C, suggesting that Asp126 is required for signal transduction. Mutagenesis of Asp133 to alanine indicated that it was critical only for the binding of BMS-182874. In the ETB receptor, mutation of His150 to alanine or tyrosine indicated that it plays a minor role in ETB subtype-selective ligand binding; mutation of the aspartates in TM2 of ETB did not alter ligand binding. As in the Asp126 Ala ETA variant, ET-1 and ET-3 failed to increase intracellular levels of inositol phosphates in the Asp147Ala ETB mutant. Taken together, these data support the hypothesis that Asp126 and Asp133 flanking Tyr129 in TM2 of the ETA receptor play a role in defining ETA subtype-selective ligand binding but Asp147 and Asp154 that flank the His150 in TM2 of the ETB receptor do not. Furthermore, these data indicate that Asp126 in ETA and Asp147 in ETB are important for transmembrane signaling via phospholipase C.

Assessing benefits of combining biochemical and immunological markers in patients with lung carcinoma

Establishment of a simple biochemical index for diagnosis of cancer and management of patients with neoplastic diseases remains one of the important goals to be achieved in cancer research. The current investigation determined serum levels of carcinoembryonic antigen (CEA), total sialic acid (TSA) and lipid bound sialic acid (LSA) in 192 untreated lung cancer patients and compared with 80 age- and sex-matched controls (44 non-smokers and 36 smokers). The levels of all the markers were significantly elevated (P < 0.001) in lung cancer patients compared to the controls. CEA and LSA values were significantly raised (P < 0.001 and P < 0.01, respectively) in smokers compared to non-smokers. TSA and LSA values were more sensitive than CEA for diagnosis of lung cancer. Mean values of the three markers were higher in non-responders (n = 5) compared to the responders (n = 10). The results suggest that along with CEA, TSA and LSA might be included as routine parameters in lung cancer patients.

Mutation of peptide binding site in transmembrane region of a G protein-coupled receptor accounts for endothelin receptor subtype selectivity

The molecular basis for endothelin (ET) isopeptide selectivity between ETA and ETB receptors was studied by examining ligand binding to several site-specific mutants of the human ETA receptor. Based on a computer-built three-dimensional model of the ETA receptor, five non-conserved amino acids, clustered around the putative ligand binding site, were targeted for mutation to alanine. Expression of the wild-type and mutant ETA receptors in COS-7 cells revealed that the binding profile of one of the ETA mutants, Tyr129-->Ala, was characteristic of the ETB receptor. In the Tyr129-->Ala ETA receptor mutant the affinity of two ETB-selective agonists, endothelin-3 and sarafotoxin S6c, was increased 10-200-fold, whereas that for two ETA-selective antagonists, BQ-123 and BMS-182874, was reduced 350-2,000-fold. Thus, mutation of a single amino acid in the second transmembrane region of the wild-type ETA receptor results in subtype conversion. In addition, these data represent the first example of peptide interactions with a transmembrane region of a G protein-coupled receptor and indicate that Tyr129, located in the second transmembrane region of the ETA receptor, is a critical component for determination of endothelin receptor subtype-selective ligand binding.

Manumycins E, F and G, new members of manumycin class antibiotics, from Streptomyces sp

Three new manumycin class antibiotics, namely manumycins E, F and G, were isolated from the culture broth of Streptomyces sp. strain WB-8376. Their structures were established by spectroscopic methods, and the S configuration of C-4 in the epoxycyclohexenone moiety was determined by CD exciton chirality method for each of the three compounds. Manumycins E, F and G are active against Gram-positive bacteria, and have moderate inhibitory effects on the farnesylation of p21 ras protein. They demonstrated weak cytotoxic activity against human colon tumor cell HCT-116.

Clinical application of serum levels of sialic acid, fucose and seromucoid fraction as tumour markers in human leukemias

To establish a blood-based biochemical profile for diagnosis and management of human leukemias, serum total sialic acid/total protein, lipid bound sialic acid, fucose/total protein and seromucoid fraction (quantitated as its hexoses and protein contents) levels were measured by highly specific spectrophotometric methods. Compared to the controls (n = 150), all the biomarkers were significantly elevated in anemia patients (pathological controls, n = 77) and untreated leukemia patients (n = 145). Furthermore, significantly raised levels of the markers were observed in untreated leukemia patients compared to anemia patients. Fucose/total protein was the most specific (71.0%) marker, while hexose levels were the most sensitive (93.0%) marker for leukemia. The levels of the biomarkers in patients with persistent leukemic activity/accelerated leukemic phase were significantly higher than those in patients in remission and were comparable with pretreatment levels. The study suggested that the markers evaluated are useful in diagnosis and treatment monitoring of leukemia patients.

Combined use of serum enzyme levels as tumor markers in cervical carcinoma patients

Enzymology has acquired a prominent place in human pathology, and serum enzyme investigations have become a prerequisite for various diseases, including cancer. Serum phosphohexose isomerase (PHI), aldolase (ALD) and alkaline phosphatase (ALP) levels were evaluated in 90 untreated patients with cervical carcinoma and 84 healthy age-matched females (controls). The concentrations of the three enzymes were significantly raised (p < 0.001) in patients compared to the controls. Receiver operating characteristic curve analysis revealed higher sensitivities of PHI and ALP, as compared to ALD at different specificity levels between 60 and 95%. Combined use of PHI and ALP revealed increased sensitivity and specificity. Combined use of PHI, ALD and ALP revealed a greater number of responders with enzyme values within the normal range than nonresponders. The results suggest that combined evaluation of the enzymes might be helpful to establish a useful aid to strengthen the armamentarium currently employed in the diagnosis and treatment monitoring of patients with cervical carcinoma.

Clinical Significance of Serum Total and Heat-Stable Alkaline Phosphatase in Leukemia Patients

Aims and Background

Variations in serum alkaline phosphatase (ALP) and placental-like (heat stable) alkaline phosphatase (PLAP) are found to be clinically useful in cancer patients. The present study evaluated serum ALP and PLAP levels to establish a blood-based biochemical index for leukemia patients.

Study design

ALP and PLAP levels were determined in 145 untreated leukemia patients, 77 anemia patients, 150 healthy individuals (controls), 47 leukemic patients in remission and 23 patients with persistent leukemic activity/accelerated leukemic phase (P. Leu./A. Leu.). The enzymes were estimated with highly specific spectrophotometric methods.

Results

Serum ALP and PLAP levels were significantly elevated in anemia patients and leukemia patients compared to controls. Comparison between anemia patients and leukemia patients showed insignificant differences for ALP, whereas PLAP levels were significantly raised (p < 0.001) in leukemia patients. ALP showed insignificant difference between untreated leukemia patients, patients with P. Leu./A. Leu. and leukemia patients in remission. PLAP levels were comparable in patients with P. Leu./A. Leu. and were significantly lower (p < 0.02) in leukemia patients in remission than in untreated leukemia patients.

Conclusions

The results indicate that serum PLAP levels are a useful biochemical marker for diagnosis and treatment monitoring of leukemia patients. However, serum ALP levels have limited utility for leukemia patients.

Importance of serum sialic acid and lactate dehydrogenase in diagnosis and treatment monitoring of cervical cancer patients

In an attempt to establish a blood-based biochemical index for diagnosis of cervical cancer and treatment monitoring of patients suffering from the disease, serum levels of total sialic acid (TSA), lipid-bound sialic acid (LSA), and lactate dehydrogenase were estimated by highly specific spectrophotometric methods. Serum concentrations of the markers in 108 untreated cervical cancer patients were compared with the levels of the biomarkers in 125 healthy, age-matched female individuals (controls). The alterations in serum levels of the markers after radiotherapy in cervical cancer patients were also observed. The levels of all markers were significantly higher (P < 0.001) in untreated cervical cancer patients compared to the controls. TSA was found to be the most sensitive (90.74%) marker for diagnosis of cervical cancer. Combined use of the markers revealed maximum (100%) sensitivity. In comparison between early (stage I+II) and advanced (stage III+IV) malignant disease, the markers showed insignificant changes. TSA and LSA values in patients who did not respond to radiotherapy were significantly higher (P < 0.05 and P < 0.001, respectively) than those of the responders. The results suggest that combined evaluation of the markers is helpful for diagnosis as well as for treatment monitoring of cervical carcinoma patients.

Usefulness of serum glycoconjugates in precancerous and cancerous diseases of the oral cavity

Sera from 47 healthy controls, 18 normal individuals with the habit of tobacco chewing, 43 patients with oral precancerous (PC) conditions, and 40 patients with oral cancer (OC) were studied for the levels of total sialic acid (TSA), lipid-bound sialic acid (LSA), mucoid proteins, and protein-bound hexoses (PBH) (galactose and mannose). The changes in the glycoconjugate levels were insignificant between the controls and the normal tobacco chewers. All four parameters were significantly elevated in oral PC patients compared with controls. The levels of PBH and LSA showed significant increase in the oral PC patients compared with the normal tobacco chewers. A significant increase was observed in the levels of TSA, LSA, mucoid proteins, and PBH in OC patients compared with controls, normal tobacco chewers, and patients with oral PC. Increasing levels of all the biomarkers were found with progression of the malignant disease. Elevations in the levels of TSA and LSA were statistically significant in Stage IV patients compared with Stage III patients. The patients with metastases had higher levels of the biomarkers than the patients with primary OC. However, elevations only in LSA levels were statistically significant. These results suggest that evaluations of the serum glycoconjugate levels may be useful in diagnosis of the patients with oral PC or OC. In addition to their value in early detection, they can also help in staging of the disease.

Evaluation of serum sialic acid, heat stable alkaline phosphatase and fucose as markers of breast carcinoma

Serum levels of total sialic acid (TSA), lipid bound sialic acid (LSA), heat stable alkaline phosphatase (HSAP) and fucose were measured in 39 patients with breast carcinoma, 14 patients with benign breast diseases and 35 healthy female individuals. Elevated levels of the four biomarkers in breast carcinoma were significant when compared with controls (p less than 0.001). Fucose levels were most sensitive (71.8%), while TSA levels were most specific (64.3%) for breast carcinoma. Sensitivity and specificity were 100% when combinations of LSA with fucose and TSA with HSAP were studied respectively. LSA was significantly elevated in infiltrating duct carcinoma patients compared with lobular carcinoma (p less than 0.001). TSA, HSAP and fucose also had lower mean values in lobular carcinoma as compared to infiltrating duct carcinoma. Increase in the levels of LSA and HSAP after surgical removal of the tumor in breast carcinoma occurred prior to the clinical evidence of the recurrence. The results indicate that the combination of the markers studied might be useful in breast cancer diagnosis and treatment monitoring.

Individual and combined usefulness of lipid associated sialic acid, mucoid proteins and hexoses as tumor markers in breast carcinoma

Serum levels of lipid associated sialic acid (LASA), mucoid proteins (MP) and hexoses (galactose + mannose) were measured in 41 breast cancer patients, 14 patients with benign breast diseases and 36 healthy age matched female individuals. In breast carcinoma patients, we have observed significant increase in the levels of the three markers compared with the controls (P less than 0.001) and in MP and hexoses compared to the patients with benign breast diseases (P less than 0.001). LASA and hexoses levels were significantly higher in benign breast diseases with respect to controls (P less than 0.001 and P less than 0.01, respectively). We evaluated the sensitivity and specificity of the markers individually and in combination. MP were most sensitive (71.8%) and specific (71.4%). Both sensitivity and specificity were increased when combinations of the markers were studied. Combination of MP with LASA was most sensitive (97.4%) while the combination of MP and hexoses was most specific (92.9%). LASA was significantly elevated in infiltrating duct carcinoma compared to lobular carcinoma (P less than 0.001). MP and hexoses also showed higher mean value in infiltrating duct carcinoma than lobular carcinoma. The present study suggests that the combination of the markers investigated might be useful for diagnosis and classification of breast carcinoma.

Serum total sialic acid and regan isoenzyme levels in patients with lung cancer

Serum total sialic acid (TSA), Regan isoenzyme (RI) (heat stable placenta like alkaline phosphatase) and TSA/Total protein (TP) ratio were estimated in 44 cases of Lung cancer using highly specific chemical methods to assess their efficacy as malignancy markers. Levels of the two markers were compared with 27 matched healthy controls. A significant increase (P less than 0.001) in both the bio-markers were compared with 27 matched healthy controls. A significant increase (P less than 0.001) in both the bio-markers was observed compared to controls. TSA/TP ratio was significantly higher (P less than 0.001) in lung cancer patients compared to controls. TSA levels were elevated in more cases of patients compared to elevations in RI. Mean values of TSA and RI were higher in epidermoid carcinoma than adeno carcinoma. The use of combination of these markers may be considered in the diagnosis of the disease in future trials.

Efficacy of serum lactate dehydrogenase and its isozymes in monitoring the therapy in patients with acute leukemia

The pretreatment levels of serum Lactate Dehydrogenase (LDH) and its isozymes are measured in 12 cases of Acute Lymphoid Leukemia (ALL) and 8 cases of Acute Myeloid Leukemia (AML) and compared with 14 matched healthy controls. Patients showed only first three bands of LDH while normal sera exhibited five bands. A significant increase in total LDH activity was observed in patients of both the groups as compared to controls at the time of admission. The patients were treated with chemotherapy and were followed at 72 hrs. and after 4 weeks. The patients who successfully responded to the therapy showed increased levels of total LDH and LDH2 and LDH3 isoenzymes as early as 72 hrs. after commencement of the therapy. The nonresponders, on the other hand, circulated, decreased or unaltered values of isozymes during this interval. Following them up for a month, ALL responders showed decreased values of total LDH activity, LDH2 and LDH3 activities when compared with their 72 hour values except LDH1. Non responders of this group had practically unaltered values of these isozymes. AML responders circulated decreased values of all the isozymes while AML non responders "showed significant increases in total LDH, and all its isozymes as compared with their 72 hour values. The determination of total enzyme and its isozyme levels at pre, mid and end of treatment seems to be a promising biochemical parameter to predict the early response to chemotherapy administered.

Efficacy of serum sialoglycoproteins as a biomarker of the disease activity & treatment monitoring in patients with base tongue malignancy

Serum levels of sialoglycoprotein constituents i.e., sialic acid, seromucoid hexoses, and mucoid proteins were determined in 34 patients with base tongue malignancy and 15 controls matched for age and sex. All three constituents were found to be significantly raised; however, only sialic acid levels increased with the severity of the disease. More than 92 per cent of the patients in each clinical stage showed abnormal values of hexoses and mucoid proteins in seromucoids. Electrophoretic separation showed a split in alpha-2-glycoprotein at pretreatment time in 67.6 per cent of the patients. On administration of radiotherapy, all three fractions decreased while alpha-2- split disappeared in 61.8 per cent patients and gamma glycoprotein peak emerged at the end of the protocol with a parallel decrease in these three constituents. It may be concluded from the data that serum sialoglycoproteins can be useful to monitor therapy in base tongue malignancy patients.

Characterization of the upstream region of the formate dehydrogenase operon of Methanobacterium formicicum

The fdhA and fdhB genes of Methanobacterium formicicum, which code for the alpha and beta subunits of formate dehydrogenase, were cotranscribed as part of a large transcript. By using Northern (RNA) gel blot analysis, the transcription start site was located within a 1.6-kilobase BglII-NcoI fragment 4.3 kilobases upstream from the fdhA gene. The precise transcription start site within the fragment was determined with the aid of primer extension analysis and S1 nuclease protection studies. A putative promoter sequence for structural genes of methanogenic archaebacteria is proposed based on a comparison of DNA sequences of the upstream region of methanogen operons for which transcription initiation sites are known. Comparison of the DNA sequence of the upstream region of the fdh operon of M. formicicum with the sequence upstream of the fdhF gene of Escherichia coli revealed regions of considerable identity.

Effect of molybdenum and tungsten on synthesis and composition of formate dehydrogenase in Methanobacterium formicicum

The influence of sodium molybdate and sodium tungstate on formate dehydrogenase activity was studied in H2-CO2-grown cultures of Methanobacterium formicicum. Depletion of molybdate from the growth medium resulted in a 75-fold decrease of intracellular molybdenum and a 35-fold decrease in enzyme activity; however, growth rate and cell yields were not influenced. By using an indirect enzyme-linked immunoassay, the amount of formate dehydrogenase approximated 3% of the total protein in cells grown in the presence of molybdate. Molybdenum-starved cells contained approximately 15-fold less formate dehydrogenase protein; Western blot (immunoblot) analysis revealed that both subunits of the enzyme were synthesized. Molybdenum starvation resulted in an increase in the amount of mRNA that hybridized to fdh-specific DNA. The results indicated an inverse relationship between the amount of transcript and the amount of formate dehydrogenase protein detected in response to molybdenum starvation. The addition of 1 mM tungstate to molybdate-containing media resulted in nearly complete loss of enzyme activity and decreased the intracellular concentration of molybdenum 10-fold. Cells grown in the presence of tungstate synthesized high amounts of inactive formate dehydrogenase and contained mRNA that hybridized to fdh-specific DNA in amounts similar to that in cells grown with sufficient molybdate. Inactive formate dehydrogenase, purified from cells grown in the presence of tungstate, had the same subunit composition and contained amounts of molybdopterin cofactor, albeit metal-free, comparable to those in the active enzyme.