Absence of airway hyperreactivity to methacholine in a worker sensitized to toluene diisocyanate (TDI)

A worker with occupational asthma due to toluene diisocyanate (TDI) was studied. Detailed immunologic studies, including those for p-tolyl isocyanate IgE antibodies and the presence of leukocyte inhibition factor for isocyanate antigen, were negative. Clinically, the subject noted more pronounced symptoms beginning on Monday morning, followed by weekend off work, and lessening of her symptoms over the working week. Methacholine challenges were negative when performed on three separate occasions, including the time when maximum symptoms were present, and again six months later, before and after bronchial challenge testing. A dose-related response to TDI was observed on bronchial provocation testing using nonirritating concentrations of TDI of 0.0165 and 0.030 ppm. This case provides evidence that the response of the airway to TDI may not always be accompanied by hyperreactivity to methacholine. Screening programs utilizing methacholine challenges may not always identify sensitized workers, since a negative methacholine challenge test does not exclude TDI sensitization.

Increased incidence of choroidal malignant melanoma occurring in a single population of chemical workers

In five patients with choroidal melanoma occurring among present or former workers of the duPont Belle, West Virginia, plant the involved eye was enucleated and histopathologic confirmation of the diagnosis was made. This represents a statistically significantly greater than expected occurrence of choroidal melanomas in the white male study population.

Hall-effect hysteresigraph for amorphous bubble-domain materials

A hysteresigraph is described which provides a much more rapid measurement of the coercivity of amorphous bubble films than any previously used method. This device utilizes the Hall effect to sense the film magnetization and has sufficient sensitivity and stability that coercivities as low as approximately 1 Oe can be readily measured. Although this device cannot provide an absolute measurement of saturation magnetization, approximate values of this quantity can be inferred from the saturation field indicated by the hysteresis loop. A probe-contact arrangement is employed which permits measurements to be made even on films having an insulating passivation layer.

Distribution and prevalence of spotted fever group rickettsiae in ticks from South Carolina, with an epidemiological survey of persons bitten by infected ticks

Live ticks removed from human hosts were tested for the presence of spotted fever group rickettsiae from 1974 through 1976. Spotted fever group rickettsiae were detected in Dermacentor variabilis, Amblyomma americanum, Amblyomma maculatum, and Ixodes scapularis. Persons from whom positive ticks were removed in 1974 and 1975 were questioned about ensuing illness. Eleven of 51 persons from whom rickettsia-positive D. variabilis were removed reported some unexplained combination of symptoms compatible with Rocky Mountain spotted fever. Persons with positive ticks other than D. variabilis reported no illness in the 2 weeks following exposure. D. variabilis from the Coastal Plain of South Carolina have a higher percentage of infection than those from the Piedmont region. Conversely, most reported human cases of spotted fever are from the Piedmont.

Listeria monocytogenes infection in neonates: Investigation of an epidemic

From March 10 through October 29, 1975, Listeria monocytogenes infection occurred in seven neonates born at a 401-bed general hospital in Greenville, S.C. In the preceding 19 months, there had been only one case. Six of the seven isolates from the infected infants were of serotype JB. Risk of listeriosis in neonates was associated with being born to mothers of low socioeconomic status and being born to mothers who had had vaginitis during pregnancy. Nosocomial transmission of L. monocytogenes appeared unlikely, but the source of the infection is unknown. Of the media used in this study for isolation of L. monocytogenes from mixed cultures, McBride's agar and McBride's agar with nalidixic acid were most useful.

Preparation and antitumor evaluation of water-soluble derivatives of dichloro(1,2-diaminocyclohexane)platinum(II)

The structure of the antitumor agent, dichloro(1,2-diaminocyclohexane)platinum(II) (NSC-194814), was modified by replacing the chlorides with organic or inorganic anions. Eighteen new platinum complexes were so isolated and their antitumor properties against the L1210 leukemia in C57BL/6 X DBA/2 mice were evaluated. Most of the complexes were readily soluble in water and some had enhanced antitumor activity compared to the parent dichloro complex. In addition, increased solubility with retention of significant antitumor activity was obtained by oxidizing the parent dichloroplatinum(II) complex with halogen or peroxide to give two platinum(IV) complexes. Some previously reported platinum complexes with phosphorus, selenium, or tellurium electron donor ligands were also synthesized and assessed for antitumor action, but these did not show appreciable activity.

Chemotherapy of advanced L1210 leukemia with platinum compounds in combination with other antitumor agents

Six antitumor platinum compounds were used in combination with cyclophosphamide (CY) plus one of five other antitumor drugs in the treatment of advanced (Day 3) L1210 leukemia in (C57BL/6 X DBA/2)F1 mice. The combination of CY with a platinum compound yielded a collective cure rate of 24%; the addition of a third drug to the dual regimen increased the collective cure rate to 55%. The most effective drugs when used in combination with platinum compounds plus CY were, in increasing order of efficacy, 5-fluorouracil, hydroxyurea, and methotrexate. No toxic deaths occurred with any regimen at the dose levels used.

Combination chemotherapy of L1210 leukemia with platinum compounds and cyclophosphamide plus other selected antineoplastic agents

Six antitumor platinum compounds were used in combination with cyclophosphamide plut 1 of 7 other antitumor drugs for treatment of L1210 leukemia in B6D2F [C57BL/6 X DMA/2) F] mice. Data obtained from each three-agent regimen were compared with those obtained after administration of each compound alone and each appropriate two-agent combination. No cure (greater than 60-day survival) was obtained with any compound used alone. Combination of cyclophosphamide with a platinum compound (Pt+CY) yielded a collective cure rate of 193/420, and the addition of a third cure rate to 290/420 (P less than 0.001). Certain regimens produced 100% cure rates. The most effective drugs when used in combination with PT+CY were cytosine arabinoside, 5-fluorouracil, hydroxyurea, and Yoshi-864. Adriamycin, methotrexate, and vincristine were less effective at the doses used. Toxicity, as evidenced by maximum weight loss, was slightly greater with the three-agent combinations than with the Pt+CY regimens.

Antileukemic properties of organoplatinum complexes

The antitumor activity of 46 cis-amineplatinum congeners was evaluated against L1210 leukemia in (C57BL/L X DBA/2)F1 mice. Several compounds in this series significantly prolonged the life-spans of mice with the leukemia. During the selection of the compound that yielded optimal activity [dichloro(1,2-diaminocyclohexane)platinum], the chlorides were substituted with various organic and inorganic anions. The aqueous solubility was greatly increased with retention of significant antileukemic activity. Most of the active compounds were synergistic with cyclophosphamide, and cure rates up to 80% were obtained with certain combinations.

Effect of lithium of responsiveness of rat uterine smooth muscle to angiotensin

Studies were carried out to investigate the effect of Na+ deprivation on the response of rat uterine smooth muscle to angiotensin II (AII). Replacement of Na+ with Li+ in a low-Ca2+-, Mg2+-free solution resulted in a concentration-dependent inhibition of both AII and acetylcholine (ACh)-induced contractions. Inhibition was noted at 10% Li+ substitution and was usually complete when 50% of the Na+ was replaced by Li+. The inhibition was not observed when an equivalent amount of tris(hyroxymethyl)aminomethand (Tris+) or sucrose was used to replace Na+. However, elevation of Ca2+ concentration from 0.2 to 0.5 mM did prevent full expression of the Li+ inhibition of AII. The Li+ effect was rapid in onset (60% inhibition after 5 min preincubation) and readily reversible following removal of the Li+. If, however, the tissue was placed in a depolarizing solution (151 mM KCL), Li+ inhibition of AII WAS NO LONGER OBSERVED. These results are interpreted to mean that Li+ interferes with an essential Ca2+-dependent step involved in membrane excitation following agonist-receptor interaction. The results are discussed in relation to a previously suggested model for AII-induced contractions in this tissue.

Comparative effects of Yoshi-864 and busulfan on certain transplantable murine tumors

Yoshi-864 extends markedly the survival times of mice bearing L1210 leukemia or Ehrlich ascites carcinoma. Busulfan, with methanesulfonate leaving groups identical with those of Yoshi-864, is without effect. Tumor cells from mice bearing the Ehrlich tumor and treated with Yoshi-864 have a persistent reduction in ability to synthesize DNA. Synthesis of DNA in cells from mice treated with busulfan is moderately suppresed at 48 hr after treatment, but returns virtually to the control value at 72 hr.

Insensitivity of bacteria to proposed antimetabolites of D-alanyl-D-alanine

alpha-Aminoisobutyryl-d-alanine, d-alanyl-alpha-aminoisobutyric acid, and alpha-amino-isobutyryl-alpha-aminoisobutyric acid, proposed as antimetabolites of d-alanyl-d-alanine in bacterial cell wall synthesis, failed to inhibit bacterial growth.

An anatomical problem of the surgical treatment of otosclerosis

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