We describe the interaction of methyl isocyanate with reactive sulphydryl groups of rat erythrocyte membrane proteins. Intraperitoneal administration, as well as in vitro incubation of methyl isocyanate, caused a significant reduction in the free sulphydryl content of erythrocyte membrane proteins. [1-14C]Methyl isocyanate was specifically bound to band III of the erythrocyte membrane and caused the breakdown of band III proteins.

Animals↗

PubMedDate not supplied

Pedicled omental graft in repair of large, difficult vesicovaginal fistulae.

Large vesicovaginal fistulae, particularly those associated with urethral loss, present formidable repair problems. Omentum, recognized for its role in resolving abdominal infection, is successfully used for pedicle grafts in these complex situations. The authors present their experience in 25 cases, describing modifications of an earlier procedure.

Adolescent↗

PubMedDate not supplied

Radionuclide detection of gastroesophageal reflux in children suffering from recurrent lower respiratory tract infection.

Radionuclide gastro-esophageal scintigraphy was performed on 25 control and 183 children suffering from recurrent lower respiratory tract infection. Gastro-esophageal reflux (GER) of varying grades was observed in 135 patients. The severity of clinical symptoms in the patients was found to be directly related to the severity of reflux observed in the radionuclide study. In some patients an attempt was also made to quantitate GER by calculating the Gastro-esophageal reflux index. The results of the scintigraphic study were correlated with the results of the other commonly used and more conventional Barium swallow and fluoroscopy study. Gastro-esophageal scintigraphy was found to be much superior in terms of sensitivity, specificity and accuracy in detecting GER. It was also possible to objectively evaluate and monitor response to treatment following conservative or corrective surgical therapy using the radionuclide technique. The results of the study demonstrated a remarkably high incidence of GER in the patients. Whether GER is the cause of recurrent lower respiratory tract infection or not is difficult to establish firmly. But within the preview of the study the association seems to be very strong and cannot be easily ignored.

Child↗

PubMedDate not supplied

Human immune response to monoclonal antibody-enzyme conjugates in ADEPT pilot clinical trial.

The human immune response to monoclonal antibody-enzyme conjugates has been studied in patients included in the pilot clinical trial of ADEPT. Each patient received murine monoclonal anti-CEA antibody fragments (A5B7-F(ab')2, conjugated to bacterial enzyme, carboxypeptidase G2 (CPG2) followed by a galactosylated monoclonal anti-CPG2 antibody (SB43), 36-48 h after the conjugate. Some patients were also given a dose of 131I-labeled conjugate (4-8 mg, 7-15 mCi) for blood clearance and gamma camera image studies. All patients studied developed human antimouse antibodies (HAMA) and anti-CPG2 antibodies within 10 d after a single course of treatment with the conjugate. In most cases, IgM response was detected at 7 d after the conjugate followed by the IgG response 14 d later. In one patient, HAMA and anti-CPG2 antibodies of the IgG type could still be detected at 10 mo after treatment. Anti-CPG2 antibodies in serum of one patient were found to inhibit CPG2 activity in vitro. Generation of neutralizing antibodies limits the use of repeat cycles of ADEPT in patients. Use of immunosuppressive agents may allow a useful time window for several ADEPT cycle treatments by delaying the appearance of HAMA and anti-CPG2 antibodies. Patients given cyclosporin A before and during ADEPT are currently being studied for HAMA and anti-CPG2 response.

Animals↗

PubMedDate not supplied

Identification of prodrug, active drug, and metabolites in an ADEPT clinical study.

Antibody-directed enzyme prodrug therapy (ADEPT) involves two phases. The first is an antibody-enzyme conjugate that localizes to tumor. The second phase is a prodrug that is administered when the enzyme-conjugate has cleared from blood and other nontumor tissues. In the pilot-scale clinical trial, the prodrug has been measured--in the plasma of patients, by liquid chromatography (HPLC) and by liquid chromatography-mass spectrometry (LC-MS). Active drug has been detected and metabolites identified. An indirect measurement of enzyme-conjugate in the plasma of patients has also been developed.

Animals↗

PubMedDate not supplied

Expression and characterization of chimeric rDNA proteins engineered for purification and enzymatic cleavage.

A strategy for the purification and cleavage of chimeric recombinant proteins based on a genetically engineered metal-binding peptide and a human renin cleavage site is described. Vectors were constructed to direct the synthesis of chimeric human immunodeficiency virus (HIV) reverse transcriptase (RT) or beta-galactosidase in Escherichia coli. As shown below, two control chimerics without the metal-binding peptide were also included: 1. Pro-Ile-His-Asp-His-Asp-His-Pro-Phe-His-Leu-Val-Ile-His-Ser-HIV RT 2. Pro-Ile-His-Asp-His-Asp-His-Pro-Phe-His-Leu-Leu-Tyr-Tyr-Ser-HIV RT 3. Pro-Ile-Pro-Phe-His-Leu-Val-Ile-His-Ser-HIV RT 4. Pro-Ile-Pro-Phe-His-Leu-Leu-Tyr-Tyr-Ser-HIV RT 5. Pro-Ile-His-Asp-His-Asp-His-Pro-Phe-His-Leu-beta-galactosidase Both N-terminal sequencing and an enzyme-linked immunosorbent assay utilizing antibodies to the metal-binding peptide were used to characterize the purified chimeric proteins. The relative RT activity of the chimeric protein was indistinguishable from the HIV-1 RT without the fusion sequence, indicating that the metal-binding and renin-cleavage sequences have no effect on the polymerase function of HIV-1 RT. The cleavage by recombinant human renin occurred at the expected site. A future paper will describe results on the use of genetically engineered alternating histidines in the purification of these chimerics by immobilized metal affinity chromatography.

Amino Acid Sequence↗

PubMedDate not supplied

Iron transport mediated drug delivery systems: synthesis and antibacterial activity of spermidine- and lysine-based siderophore-beta-lactam conjugates.

Conceptually, the penetration of beta-lactam antibiotics through the bacterial cell wall can be enhanced by utilizing various active transport systems such as the active iron-transport system that exists in bacteria. Several beta-lactam-siderophore analogue (microbial iron chelators) conjugates were prepared to investigate this approach. Thus, monocyclic (oxamazin) and bicyclic (carbacephalosporin) beta-lactams were separately linked to dihydroxybenzoyl derivatives of spermidine and lysine. The antibacterial activity of these conjugates has been investigated and the potential use of the iron-transport system as a drug-delivery system is discussed.

Anti-Bacterial Agents↗

PubMedDate not supplied

Biochemical and molecular markers in renal cell carcinoma: an update and future prospects.

Cancer is a big problem in the developed world as well as in developing countries. Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90-95% of neoplasms arising from the kidney. RCC is more common in men than in women (2:1), and it most often occurs in patients between the ages of 50-70 years. In all cancers the cancerous cells release particular kind of proteins (called tumour markers) and blood tests are used to detect the presence of these markers. These tumour markers nowadays are an area of interest for oncologists who search for a possible solution in the detection and treatment of RCC. Different kinds of biochemical and molecular markers such as ferritin, MN/CA9, apoptotic index, p53, IL-2, gamma-enolase, CD44, CD95, chromosome instability and loss of heterozygosity have been tested in RCC, but so far no marker fulfils one or the other criteria to be considered as an ideal marker for RCC. This review gives basic and updated information about the different kinds of biomarkers studied in RCC and about the role implementation of genomics and proteomics in RCC.

Adult↗

PubMedDate not supplied

Unstable angina pectoris and non-Q-wave myocardial infarction.

Unstable angina pectoris and non-Q-wave myocardial infarction are clinical syndromes that share many pathophysiologic and clinical features. In the spectrum of coronary artery disease, these syndromes lie between chronic stable angina and Q-wave myocardial infarction. Although both conditions are associated with significant morbidity and mortality, patients presenting with these syndromes can be further risk stratified into higher and lower risk based on a number of readily available clinical features and biochemical parameters. Such risk stratification can allow for more tailored treatment and better resource allocation. Although routine early coronary angiography and revascularization has not been shown to be superior to conservative management, certain high-risk patients may benefit from a more aggressive strategy. Medical therapy with the use of antiplatelet, anticoagulant, and antiischemic agents remains the cornerstone of emergent treatment for patients presenting with these syndromes. The recent demonstration of a reduction in both morbidity and mortality with the glycoprotein IIb/IIIa antagonists has further expanded the armamentarium of available agents. Following initial stabilization, risk stratification with stress testing can help identify patients with a large residual ischemic burden who may benefit from coronary angiography with revascularization if feasible.

Age Factors↗

PubMedDate not supplied

Seizure activity in pyridoxine-deficient adult rats.

This investigation tested the hypothesis that the degree of pyridoxine depletion rather than the status of neuronal maturity determines seizure proneness in the pyridoxine-deficient rat. Dietary pyridoxine deficiency was induced in neuronally mature rats. Seizure activity was monitored using computerized EEG analysis. Dietary pyridoxine deficiency of 10 weeks' duration induced in neuronally mature rats led to spontaneous convulsive seizure activity. Even moderately pyridoxine-deficient adult rats (on the deficient diet for less than 8 weeks) exhibited seizure-like diffuse spike and wave activity and electrocortical inhibition. Picrotoxin-, pentylenetetrazol-, or domoic acid-induced seizure thresholds were significantly reduced in pyridoxine-deficient rats when compared with normal controls. Pyridoxine-deficient rats exhibited increased dominance of delta and theta activities and increased hemispherical asymmetries in response to convulsant treatment.

Age Factors↗

PubMedDate not supplied

Coenzyme Q10 inhibits mitochondrial complex-1 down-regulation and nuclear factor-kappa B activation.

We have used control-homozygous weaver mutant, and -heterozygous weaver mutant mice in order to explore the basic molecular mechanism of neurodegeneration and the neuroprotective potential of coenzyme Q(10). Homozygous weaver mutant mice exhibited progressive neurodegeneration in the hippocampus, striatum, and cerebellum, and a reduction in the striatal levels of dopamine and coenzyme Qs (Q(9) and Q(10)) without any significant changes in norepinephrine and serotonin. Mitochondrial complex-1 was down regulated; whereas nuclear factor-kappa B was up regulated in homozygous weaver mutant mice. Rotenone inhibited complex-1, enhanced nuclear factor-kappa B, and caused apoptosis in human dopaminergic (SK-N-SH) neurons; whereas nuclear factor-kappa B antibody suppressed rotenone-induced apoptosis, suggesting that enhancing coenzyme Q(10) synthesis and suppressing the induction of NF-kappa B, may provide neuroprotection.

Aging↗

PubMedDate not supplied

Separation of the S-adenosylmethionine: 5- and 8-hydroxyfuranocoumarin O-methyltransferases of Ruta graveolens L. by general ligand affinity chromatography.

Two S-adenosyl-L-methionine:furanocoumarin O-methyltransferases of R. graveolens, acting at the 5- and 8-hydroxyl of the psoralen nucleus, were completely resolved by adsorption on a general affinity ligand, 5-(3-carboxypropanamido) xanthotoxin, followed by specific desorption by bergaptol and xanthotoxol, respectively. The 5-O-methyltransferase was purified 450-fold by this procedure, the 8-O-methyltransferase 112-fold, and both enzyme fractions were electrophoretically homogeneous. No resolution could be achieved of the activity against two 5-hydroxypsoralens or of the activity against two 8-hydroxypsoralens, and conclusive evidence is presented for the existence of only one 5-O-methyltransferase and only one 8-O-methyltransferase acting on linear furanocoumarins.

Chromatography, Affinity↗

PubMedDate not supplied

Molecular genetic analysis of multi-drug resistance in Indian isolates of Mycobacterium tuberculosis.

A total of 116 isolates from patients attending the out-patient department at the All India Institute of Medical Sciences, New Delhi and the New Delhi Tuberculosis Centre, New Delhi, India were collected. They were analyzed for resistance to drugs prescribed in the treatment for tuberculosis. The drug resistance was initially determined by microbiological techniques. The Bactec 460TB system was employed to determine the type and level of resistance in each isolate. The isolates were further characterized at molecular level. The multi-drug loci corresponding to rpo beta, gyr A, kat G were studied for mutation(s) by the polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) technique. The SSCP positive samples were sequenced to characterize the mutations in rpo beta, and gyr A loci. While previously reported mutations in the gyr A and rpo beta loci were found to be present, several novel mutations were also scored in the rpo beta locus. Interestingly, analysis of the gyr A locus showed the presence of point mutation(s) that could not be detected by PCR-SSCP. Furthermore, rifampicin resistance was found to be an important marker for checking multi-drug resistance (MDR) in clinical isolates of Mycobacterium tuberculosis. This is the first report on molecular genetic analysis of MDR tuberculosis from India, and highlights the increasing incidence of MDR in the Indian isolates of M. tuberculosis.

Humans↗

PubMedDate not supplied

Osteosarcoma of the orbit.

A rare case of osteosarcoma of the orbit in a 10-year-old female child is reported.

Child↗