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Proteomic searches using affinity-based chromatography (e.g., biotin-[strept]avidin) have been severely hampered by low protein recovery yields, protein destruction and denaturation, and the release of background proteins from the support. These limitations confound protein identification. A new acylhydrazone-based cleavable linker was developed to permit the efficient isolation of proteins with a traceable tag allowing detection and identification under mild conditions. The utility of the acylhydrazone linker was validated in a proteomic search wherein aldehyde dehydrogenase-1 was selectively captured and isolated from the mouse soluble liver proteome without interfering background proteins. The use of acylhydrazone linkers is expected to be generalized, allowing for the selective release of tagged molecules from noncovalent and covalently tagged supports.

Bismuth-dithiol mixtures are proven antimicrobial agents with unknown mechanism(s) of action. We show that select bismuth-dithiol solutions inhibit the Escherichia coli rho transcription termination factor. Rho is an essential enzyme in most Gram-negative prokaryotes and without rho function the cells are not viable. Bismuth complexes with 2,3-dimercapto-1-propanol (BiBAL) (3:1 solutions) functioned as a noncompetitive inhibitor with respect to ATP in the rho poly(C)-dependent ATPase assay (I50=60 microM) and as a competitive inhibitor with respect to ribo(C)10 in the poly(dC)-ribo(C)10-dependent ATPase assay. The minimum inhibitory concentration (MIC) of bacterial growth for BiBAL (3:1) in the liquid culture assay using E. coli W3350 was 16 microM. Using the tnaA/lacZ fusion reporter assay we showed that sublethal amounts (3 microM) of BiBAL (3:1 solution) led to a small increase (37%) in in vivo beta-galactosidase activity in E. coli SVS1144, which corresponds to antitermination of the tna operon as a result of rho inhibition. We concluded that BiBAL was a potent in vitro rho inhibitor but its effect on in vivo rho processes was modest indicating that other mechanisms contributed to the antibacterial activity of BiBAL. Our study suggests that structural changes in the dithiol unit that provide greater bismuth binding may improve rho specificity, a macromolecular target not previously recognized for bismuth therapy.

Objective: To examine whether Canadian women seeking care from obstetrician-gynaecologists prefer to see female or male physicians or have no strong preference in this regard., Methods: A self-administered questionnaire assessing women's "strong preference" for female or male obstetrician-gynaecologists, or their lack of a strong preference in this area, was completed by 409 women (93.8% response rate) attending two hospital-based obstetrics and gynaecology outpatient clinics in London, Ontario., Results: Overall, 75% of women stated that they had no strong preference concerning the gender of their obstetrician-gynaecologist; 21% strongly preferred a female obstetrician-gynaecologist; and 4% strongly preferred a male obstetrician-gynaecologist. Women who were single, pregnant, or had a history of abortion, sexual coercion, relationship violence, sexual dysfunction, or sexually transmitted disease were no more likely to prefer to see a female obstetrician-gynaecologist than were women without these characteristics., Conclusion: A clear majority of women expressed no strong preference for the gender of their obstetrician-gynaecologist, and preference for a female obstetrician-gynaecologist was not associated with a history of sensitive gender-related medical concerns. Nationally representative research is needed to clarify women's preferences in this domain across the regions of Canada and to determine the strength and correlates of any such preferences. Patient care and human rights implications of women's preference for the gender of their obstetrician-gynaecologist will need to be carefully considered as well.

Background: Ecteinascidin 743 (Et 743), a natural product derived from a marine tunicate, is a potent antitumor agent presently in phase II clinical trials. Et 743 binds in the minor groove of DNA and alkylates N2 of guanine via a unique mechanism involving catalytic activation. The sequence selectivity of Et 743 is governed by different patterns of hydrogen-bonding to DNA, which results in differential reversibility of the covalent adducts. As determined by nuclear magnetic resonance spectroscopy, the preferred sequences 5'-PuGC and 5'-PyGG are stabilized by a hydrogen-bonding network, while the non-preferred sequences 5'-NG(A/T) are much less stabilized due to the lack of a key hydrogen bond to the GC base pair on the 3'-side of the alkylated guanine., Results: Mammalian cell lines (XPB, XPD, XPF, XPG, and ERCC1) deficient in the nucleotide excision repair (NER) gene products show resistance to Et 743. The recognition and subsequent incision of Et 743-DNA adducts by the bacterial multisubunit endonuclease UvrABC were used to evaluate DNA repair-mediated toxicity as a rationale for the resistance of NER-defective cell lines and the antitumor activity of Et 743. The Et 743-DNA adducts are indeed recognized and incised by the UvrABC repair proteins; however, the pattern of incision indicated that the non-preferred, and less stable, sequences (i.e. 5'-NG(A/T)) modified with Et 743 are generally incised at a much higher efficiency than the preferred, more stable sequences (i.e. 5'-PuGC or 5'-PyGG). In addition, within the same Et 743 recognition sequence, the level of incision varies, indicating that flanking regions also contribute to the differential incision frequency., Conclusions: The inefficient repair incision by the UvrABC nuclease of Et 743-DNA adducts provides a basis for rationalizing the observed repair-dependent cytotoxicities of these DNA adducts, if other associated structural properties of Et 743-DNA adducts are taken into account. In particular, the wedge-shaped Et 743, which forces open the minor groove of DNA, introducing a major groove bend, and the extrahelical protrusion of the C-subunit of Et 743 provide unique characteristics alongside the hydrogen-bonding stabilization of a covalent DNA adduct, which we propose traps an intermediate in NER processing of Et 743-DNA adducts. This trapped intermediate protein-Et 743-DNA adduct complex can be considered analogous to a poisoned topoisomerase I- or topoisomerase II-DNA complex. In the absence of an intact NER nuclease complex, this toxic lesion is unable to form, and the Et 743-DNA adducts, although not repaired by the NER pathway, are less toxic to cells. Conversely, elevated levels of either of these nucleases should lead to enhanced Et 743 toxicity.

Aims: The aim of this study was to develop a criterion with a high negative predictive value for the evaluation of breast lesions. We aimed to determine the value of combining three non-invasive tests, mammography (MM), ultrasonography (USS) and 99mTc-methoxyisobutylisonitrite (99mTc-MIBI) scintimammography (scinti-MM)., Methods: We included 94 consecutive patients with suspected lesions detected by mammography or on physical examination. MM, USS and scinti-MM were performed no more than 4 weeks prior to excisional biopsy in all patients. We then compared the biopsy results with a score calculated for each patient, derived from the results of the three tests, which we termed 'mamma malignancy index' (MMI)., Results: Each of the three exams yielded a score ranging from 0 to 2, with 0 representing an almost certainly benign lesion, 1 an indeterminate finding and 2 a likely malignant lesion, and hence giving a total score ranging from 0 to 6. The biopsy results showed that the lesions in 64 patients were benign. Forty-nine (77%) of these patients had received an MMI score of 0 or 1. The negative predictive value for malignancy in patients with a score less than 2 was 100%., Conclusions: Since the smallest detected lesion was 9 mm in diameter, we conclude that MMI may be a highly useful diagnostic tool in the delineation of breast lesions > or =1 cm which should not be routinely referred for biopsy but may be followed non-invasively. Although fine needle aspiration has limitations, we would recommend it as a less invasive method to evaluate suspected lesions smaller than 1 cm., (Copyright 2000 Harcourt Publishers Ltd.)

Golf interest is on the increase, resulting in a corresponding increase in golf-related tendon injuries. Injuries are best avoided by a good strength and flexibility program, proper warm-up exercises, and good stroke mechanics. Treatment is directed toward restoring the integrity of the muscle/tendon unit at the elbow and preventing recurrences.

The primary site of action for the novel antibiotic, bicyclomycin, in Escherichia coli has been identified to be the rho transcription termination factor. The inhibition of rho poly(C)-stimulated hydrolysis of ATP by bicyclomycin has been found to proceed by a non-competitive, reversible pathway with respect to ATP (Ki = 20 microM). Inhibition by dihydrobicyclomycin was similar (Ki = 75 microM). No change in the inhibitory properties of the antibiotic was observed under the assay conditions with the two rho mutants, Cys202Gly and Cys202Ser, indicating that Cys-202 does not affect drug binding to rho. Prolonged incubation (32 degrees C, 12 h) of wild-type rho with bicyclomycin (20 mM) led to protein degradation and a slow, permanent loss of rho ATPase activity after dialysis. Evidence was obtained that trace amounts of proteases present with bicyclomycin were responsible for the observed protein degradation. Treatment of wild-type and mutant rho proteins with purified bicyclomycin (25 mM) led to approximately 80% loss of ATPase activity after dialysis with no apparent loss of protein. However, a reduction of the electrophoretic mobility of the bicyclomycin-treated rho versus wild-type rho was seen. Addition of either ATP or poly(C) to wild-type rho led to partial protection against bicyclomycin inactivation, while inclusion of both ligands provided near complete protection against inactivation. The observed loss of ATPase activity upon prolonged incubation of rho with excess purified bicyclomycin is attributed to the covalent modification of the protein by the antibiotic at multiple sites.

Recent studies have demonstrated that functionalized alpha,alpha-diamino acids (1) display excellent activity when evaluated in the maximal electroshock seizure (MES) test in mice. The synthesis and pharmacological evaluation of 14 select analogues within this series of compounds are detailed. Included in this survey were 10 N-acyl derivatives in which the basic C(alpha) N-group in 1 was replaced by a neutral N-substituent and four dipeptides where the amino acid fusion point was the alpha-carbon site. N-Acylation of 1 led to decreased anticonvulsant activity. The importance of these findings in relation to the requirements of the C(alpha) substituent for anticonvulsant activity in 1 are briefly discussed.

Selectively substituted 3-oxo-4-substituted 1,2,5-thiadiazolidine 1,1-dioxides (2, four examples), and 3-imino-4-substituted 1,2,5-thiadiazolidine 1,1-dioxides (3, eight examples) have been evaluated in the maximal electroshock seizure (MES), subcutaneous pentylenetetrazole seizure threshold (scMet), and rotorod (Tox) tests. These compounds can be considered as sulfonyl analogues of hydantoins (1). In those cases where comparison between 1 and 2 (or 1 and 3) was possible, replacement of the central carbonyl group in 1 by a sulfonyl moiety led to a significant reduction or abolition of the anticonvulsant activity.

This article details the development, delivery, and evaluation of a six-session nutrition course entitled "Eating Today for a Healthier Tomorrow." The course addressed nutrition practices associated with the reduction of risk for coronary heart disease, cancer, osteoporosis, and obesity. Teaching teams, consisting of an extension agent and a registered dietitian, were used in course delivery. A wide variety of printed and audiovisual teaching aids helped participants learn through discussion, goal setting, games, and food tasting. Evaluation components of the course included demographic and pre- and post-course food frequency information as well as an overall evaluation by each participant. Post-course evaluation data were collected at a reunion session held 2 months after course completion. One hundred forty-two of 195 participants (73%) completed the course and the evaluation. Three-fourths of the participants had a family history of at least one of the life-style diseases addressed by the course. The food frequency results indicated that participants made some significant changes in their food practices. They decreased the number of times they selected high-fat cheese, regular red meats, foods from the saturated fatty acid group, desserts, sodium-rich products, and tea/coffee (p less than .05), and they increased selection of low-fat dairy products (p less than .05). Further study is recommended to determine whether individuals maintain the dietary changes and how those changes affect others in the person's immediate environment.

The value of different factors are examined to assess activity in 60 patients with biopsy-proven sarcoidosis. In patients with active sarcoidosis (n = 35), 67Gallium scans proved to be the most sensitive method (94 percent sensitivity), followed by serum angiotensin I converting enzyme (S-ACE) levels, chest x-ray films, and lymphocyte assays. In patients with peripheral pulmonary lesions, chest x-ray films failed in 32 percent of cases to document activity (68 percent sensitivity) whereas 67Ga scans and S-ACE levels remained to give reliable results. Despite poor specificity, negative 67Ga scans together with normal ACE levels have a high predictive value for exclusion of active sarcoidosis. In patients with peripheral pulmonary lesions, chest roentgenography is of doubtful value for staging lung involvement and assessment of activity including monitoring and control of therapy.

This report presents follow-up information on 497 women diagnosed with cancer of the uterine cervix in Connecticut and California between 1932 and 1951 who received only radiation as their initial course of therapy. Patients entered into the study were all treated before age 55 and all were five-year-survivors following treatment in order to eliminate early deaths due to the cervical cancer. Three radiologic dosage groups (high, medium, and low) were formed with 93, 244, and 160 patients, respectively. For all dosage groups combined 108 subsequent cancers were observed more than 5 yr after cancer treatment compared with 64 expected (P less than 0.01). Sites for which subsequent cancers were significantly (P less than 0.05) in excess of expectation were rectum, ovary, lung, vulva and vagina, small intestine, oropharynx, and central nervous system excluding brain. The ratio of observed to expected cases of subsequent cancers rose only slightly with increasing radiologic dose. No significant differences in overall survival patterns for the three dosage groups were found. For all dosage groups survival was poorer than in the corresponding segment of the general population.

The induction of histocompatibility gene mutations in BALB/cKh mouse sperm was determined following doses of 0, 350, or 350 + 300 rad (24 h apart) of 250 kV X-rays. The mutation rate is significantly lower than predicted on the basis of the seven-locus test and is not significantly different from the very low rate of H-loci in BALB/cKh spermatogonia. Furthermore, selection and repair are important in determining mutation rates per viable progeny of H-loci during both spermatogenesis and gestation.

A series of imidazolidinethiones and thioimidazolines was synthesized and tested for their effect on both forced and spontaneous motor activities as well as their ability to raise the convulsion threshold. The N-acyl-substituted 2-p fluorobenzylthioimidazolines were the most active compounds, producing protection against maximal electroshock seizures and tonic convulsions induced by pentylenetetrazol. Both compounds had high LD50 values and safety indexes.

Adult Balb/c Kh male mice were irradiated (pelvic region, 250 kVcp X-rays, 60 rad per min) and three months later were mated to untreated C57BL/6 Kh females. Their B6C F1 progeny were screened for mutations at the Class II histocompatibility loci, i.e. those that carry similar alleles in the parental lines and are therefore homozygous in the F1 progeny. The treatment groups were: single doses of 0, 350, 500, 650 and 800 rad; split doses 1 day apart, totalling 500, 650 and 800 rad; split doses averaging 52 days apart, totalling 650 and 800 rad. Thirty-six mutants were identified in 13,614 progeny. Twelve of them occurred in five clusters of two or three, presumably owing to five gonadal mosaics among 940 parents. Irradiation did not increase the spermatogonial mutation rate. The only effect of exposure appeared to be a decrease in the mutation rate of the 1-day split dose-groups compared to those with the same total doses in a single exposure or in two fractions, 52 days apart.