Methodology of serial ECG classification using an adaptation of the NOVACODE for Q wave myocardial infarction in the Bypass Angioplasty Revascularization Investigation (BARI)

Serial electrocardiographic (ECG) changes are a critical component of the diagnostic algorithm for classification of myocardial ischemic events in large-scale clinical trials. This study describes a computerized serial ECG classification program developed at the St. Louis University Core ECG Laboratory for use in the Bypass Angioplasty Revascularization Investigation (BARI) trial, in which patients with multivessel coronary artery disease were randomized to receive either coronary artery bypass grafting or percutaneous transluminal coronary angioplasty. The St. Louis University program detects and codes serial changes in Q, ST, and T wave items according to Minnesota code (MC) criteria using a modified NOVACODE hierarchical classification system. Measurements using a seven-power calibrated coding loupe are used to generate the MC from a customized software program. Significant minor or major changes are detected by the serial comparison program and referred to a physician coder for verification. Serial comparison coding rules are used to adjust for weaknesses in the standard MC classification system resulting from instability at decision boundaries. Of 4,244 BARI randomized and registry study participants with follow-up ECGs received at the Core ECG Laboratory as of March 1995, a grade 2 MC Q wave progression was noted in 568 participants (13.4%) using MC criteria alone, as compared with 367 (8.6%) after the St. Louis University coding rules were applied. The incidence of grade 1 MC Q wave progressions was 16.4% (697/4,244) versus 6.1% (259/4,244) when the St. Louis University program was applied. Intraobserver variability for grade 2 Q wave progression codes determined from a sample of 812 serial.     

Recombinant expression and characterization of the major beta-lactamase of Mycobacterium tuberculosis

New antibiotic regimens are needed for the treatment of multidrug-resistant tuberculosis. Mycobacterium tuberculosis has a thick peptidoglycan layer, and the penicillin-binding proteins involved in its biosynthesis are inhibited by clinically relevant concentrations of beta-lactam antibiotics. beta-Lactamase production appears to be the major mechanism by which M. tuberculosis expresses beta-lactam resistance. beta-Lactamases from the broth supernatant of 3- to 4-week-old cultures of M. tuberculosis H37Ra were partially purified by sequential gel filtration chromatography and chromatofocusing. Three peaks of beta-lactamase activity with pI values of 5.1, 4.9, and 4.5, respectively, and which accounted for 10, 78, and 12% of the total postchromatofocusing beta-lactamase activity, respectively, were identified. The beta-lactamases with pI values of 5.1 and 4.9 were kinetically indistinguishable and exhibited predominant penicillinase activity. In contrast, the beta-lactamase with a pI value of 4.5 showed relatively greater cephalosporinase activity. An open reading frame in cosmid Y49 of the DNA library of M. tuberculosis H37Rv with homology to known class A beta-lactamases was amplified from chromosomal DNA of M. tuberculosis H37Ra by PCR and was overexpressed in Escherichia coli. The recombinant enzyme was kinetically similar to the pI 5.1 and 4.9 enzymes purified directly from M. tuberculosis. It exhibited predominant penicillinase activity and was especially active against azlocillin. It was inhibited by clavulanic acid and m-aminophenylboronic acid but not by EDTA. We conclude that the major beta-lactamase of M. tuberculosis is a class A beta-lactamase with predominant penicillinase activity. A second, minor beta-lactamase with relatively greater cephalosporinase activity is also present.     

A death certificate-based study of occupation and mortality from reproductive cancers among women in 24 US states

We conducted a study of occupation and mortality from reproductive cancers among women, based on death certificates from 24 US states for the period 1984-1993. There were 9,523 cervical cancer deaths, 12,335 endometrial cancer deaths, and 25,212 ovarian cancer deaths. Usual occupation and industry, which were obtained from death certificates, were coded using the 1980 Bureau of Census classification system. Mortality odds ratios (MORs) and 95% confidence intervals (CIs) were calculated, using all non-cancer deaths as the referent disease category. In general, jobs involving professional or administrative occupations were related to increased risk of mortality from endometrial and ovarian cancer, while cervical cancer mortality was increased among women employed in manufacturing, service, farm work, and health care technician and aide occupations. Associations with some occupations involving exposure to chemicals and metals, such as the associations between cervical cancer and employment in printing, typesetting, and machine operating occupations, deserve further attention. Similarly, further investigations should be made into the excess of ovarian cancer observed in several occupations in health care, an industry that has numerous hazardous exposures, including radiation, chemotherapeutic drugs, and viruses. The study results reflect, in part, socioeconomic factors and reproductive patterns but may also indicate a possible etiologic role for occupational chemical exposures.     

CT features of calcifications in abdominal malignant fibrous histiocytoma

Driven by the need for a readily available, non-immunological tissue that possesses many of the characteristics of normal human skin, tissue-engineered skin has been developed. For over a decade, laboratory grown or processed skin has been under investigation and, in some cases, available as an alternative to autologous grafts. Apligraf, derived from neonatal foreskin and bovine type I collagen, is the first bi-layered living skin equivalent approved in the US and other countries for use in venous ulcers. Apligraf is effective both in the treatment of refractory venous ulcers and for acute wounds such as surgical excision sites and split thickness donor sites. Apligraf is safe and is not clinically rejected. Its ultimate fate is not known, so it may well work to aid healing in a variety of ways including graft 'take' and as a stimulus for healing.     

Microsurgical thumb reconstruction with toe transfer: selection of various techniques

Microsurgical toe transfer is an established method for reconstruction of missing thumbs. However, there is little agreement on which of the various techniques represents the ideal transfer. Basically, selection of technique requires balancing the patient's functional needs, appearance of the reconstructed thumb, and donor-site cosmesis. Based on our experience with 103 toe-to-thumb transfers performed over the past 9 years, this paper attempts to provide guidelines for appropriate selection among the four most commonly employed toe transfer techniques (e.g., second toe, total great toe, great toe wrap-around, trimmed great toe) so that optimal results and patient's acceptance can both be achieved.     

Gray-scale ultrasound: utility preoperatively and postoperatively in a patient with obstructive jaundice

We present a case of obstructing calculi of the common bile duct diagnosed by ultrasonography. Postoperatively, a sterile abscess due to bile leakage at the distal common bile duct developed, and was also diagnosed by ultrasound Ultrasonography was useful in following the course of clearing of the bile collection. Preoperative ultrasound evaluation of the jaundiced patient should be followed by postoperative sonography, especially if complications occur.     

Efficacy of intratracheal administration of Newcastle disease vaccine in day-old chicks

Groups of day-old chicks with varying levels of parental antibody were vaccinated against Newcastle disease (B1 strain) with a commercially available device which simultaneously debeaks the chick and emits a fine spray of vaccine into its trachea. Some groups were also vaccinated (B1 or Lasota strain) with a commercially available vaccine sprayer at 9 days, 14 days, or 9 and 25 days of age. Response to vaccine was evaluated once each week during the experimental period of approximately 8 weeks HI titers were determined and 10 chicks were challenged with the Texas GB strain of Newcastle disease virus. In chicks with low to moderate levels of maternal antibody a satisfactory antibody response was attained by vaccination at 1 day of age, and in most cases resistance to challenge was evident by 3 weeks of age. Intratracheal vaccination of chicks with extremely high levels of maternal antibody had a minimal antibody response. All groups of chicks spray vaccinated at 9, 14, or 9 and 25 days of age showed a marked increase in antibody titer regardless of whether they had been vaccinated at 1 day of age.     

A survey of transformation markers in differentiating epidermal cell lines in culture

Primary mouse epidermal cells underwent spontaneous malignant transformation in culture. TWelve malignant epidermal cell lines were established which produced squamous cell carcinomas in syngeneic hosts. These lines were used to define criteria for recognizing transformed epidermal cells in vitro. Growth in suspension in agar, agarose, or Methocel was minimal for 11 of the lines. All lines tested retained specific epidermal antigens (pemphigus, pemphigoid, keratin) by indirect immunofluorescence, but keratin content was reduced when quantified by radioimmunoassay. Basal activity of ornithine decarboxylase and activity induced by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate were variable among lines. All malignant lines as well as normal epidermal cells grew well at reduced extracellular calcium concentrations. When the extracellular calcium was elevated, normal cells ceased proliferation, terminally differentiated, and sloughed from the culture dish, while malignant cells continued to proliferate although they expressed differentiative functions. These results indicate that malignant transformation in epidermis is associated with a fundamental alteration in the program of terminal differentiation which allows some cells to escape the proliferative block and cell death which accompanies differentiation in normal keratinocytes. This alteration should be useful to select for transformants during the process of carcinogenesis in vitro.