Jarisch-Herxheimer reaction in Lyme disease

The Jarisch-Herxheimer reaction includes the accentuation of symptoms during antibiotic therapy. More commonly associated with the treatment of syphilis, it can also occur in patients treated for Lyme disease caused by the spirochete Borrelia burgdorferi.

The effect on healing of the application of citric acid during replaced flap surgery

The aim of this double-blind controlled clinical trial was to assess the effect on healing following conditioning the root surface with citric acid during replaced flap surgery. Healing was assessed in 18 pairs of sites in 12 patients before surgery and after 3 months; healing was also assessed in 13 pairs of these sites in 10 of the patients after 9 months. During surgery, the root surface at 1 site from each pair was treated with citric acid pH 0.6 for 3 min and the contralateral site was exposed to sterile saline. Healing was assessed by measuring attachment levels, probing depths and recession; in addition, gingival crevicular fluid flow was measured, as was the degree of bleeding on probing. The mean gain of attachment (mm) in the acid and control groups were 1.0 and 1.2, respectively, at 3 months and 1.1 and 0.9 respectively, at 9 months. The results of this study indicate, both clinically and statistically, that the difference in healing between the acid and the non-acid sites is not significant. Thus no additional benefit is shown by using citric acid in conjunction with replaced flap surgery on anterior teeth.

Recurrent cavitary nodules secondary to Hodgkin's disease

A patient with nodular sclerosing Hodgkin's disease had at least three episodes of lung involvement consisting of an infiltrate on one occasion and multiple cavitating nodules on the other two. The cytologic and histologic studies of the lung specimens disclosed the presence of Reed-Sternberg cells on each occasion without any evidence for infection. This represents the first time in which recurrent cavitating nodules have been reported with Hodgkin's disease.

The properties of recombinant chicken growth hormone and its effects on growth, body composition, feed efficiency, and other factors in broiler chickens

Recombinant chicken GH (rcGH) was produced and characterized. Comparison of protein sequence, amino acid composition, mol wt, purity, and immunocross-reactivity showed that except for the N-terminal methionyl group arising from the bacterial expression system, the recombinant and pituitary-derived cGHs were identical. When tested in a hypophysectomized rat growth assay, the recombinant and pituitary materials had the same specific bioactivity. Within 60 min after sc injection of rcGH (480-960 micrograms/kg) in chickens, plasma GH levels increased 4- to 6-fold and remained significantly elevated for at least 5 h. Thrice-daily injections from age 2-24 days had little effect on growth or feed consumption in either male or female broiler chicks. Plasma levels of insulin and triglycerides were significantly elevated by rcGH in 24-day-old females, but not in males. Injection of rcGH counteracted a reduction of tibia length observed in saline-injected controls. The rcGH had no effect on carcass protein, ash content, or nitrogen retention. It is important to note that exogenous GH can be a productivity-enhancing factor in other commercially important species. Administration of bovine GH to cows has been shown to induce a significant increase in milk production (28). This study shows that administration of rcGH to chickens can lead to some significant metabolic effects. However, it is the conclusion of this report that the level of circulating GH is not the limiting factor in the growth of this highly selected species.

Problems facing the decision-maker in the risk assessment process

This paper presents an overview of the U.S. Environmental Protection Agency's risk assessment process, describes problems that the Agency faces in conducting risk assessment, in general, and identifies some specific problems that the Agency confronts when conducting risk assessments on suspected developmental toxicants. As noted by the NAS (National Research Council: "Risk Assessment in the Federal Government: Managing the Process." Washington, DC: National Academy Press, 1983, pp 17-83), improving the quality and comprehensiveness of knowledge is the most effective way to improve risk assessment, but some limitations are inherent and may remain unresolvable. Therefore, inferences will always be required. The Agency's challenge is to ensure that these inferences are as soundly based as possible.

Effects of whole cottonseed, cottonseed oil or animal fat on digestibility of wheat straw diets by steers

Two completely random digestion trials were conducted, each with 12 beef steers (325 kg initial weight), to measure changes in digestibilities of fat and of forage components when fat was added to diets containing 62 to 76% wheat straw. Trial 1 diets contained either no added fat or 6.3% added fat from whole cottonseed (30% of the diet), cottonseed oil or animal fat; diets were formulated to contain equal levels of cottonseed hulls and cottonseed meal. Trial 2 diets contained 0, 2, 4 or 8% added animal fat. In all forms and at all levels, added fat increased apparent digestibility of dietary lipid (P less than .05). However, estimated true digestibility of lipid decreased (from 94 to 71%) as added fat was increased from 0 to 8% (P less than .05). Up to 6.3% added fat increased digestible energy (DE) content of the diet. Fat additions of 2 and 4% increased daily DE intake (P less than .05) and did not depress digestibility of diet components (P greater than .05). Fat additions of 6.3% or greater, either as free fats or as whole cottonseed, reduced (P less than .05) mean acid detergent fiber digestibility from 40 to 28%. In addition to depressing fiber digestibility, 8% added fat reduced (P less than .05) digestibilities of dry matter (from 54 to 47%), organic matter (60 to 52%) and gross energy (60 to 51%). Oil fed as whole cottonseed caused digestibility depressions similar to free fat addition at the same level.(ABSTRACT TRUNCATED AT 250 WORDS)

Regional differences in myocyte size in normal rat heart

Three independent methods were evaluated in an effort to obtain reliable values for myocyte size in adult Sprague-Dawley rats. Cell volume was determined from isolated myocytes by a Coulter Channelyzer system. Cell volume was also determined from the product of length and cross-sectional area of isolated myocytes. Additionally, myocyte cross-sectional area was measured morphometrically from electron micrographs of whole perfusion-fixed tissue. A major goal was to determine if anatomical methods used to measure cell volume produce values comparable to the more expeditious and objective Coulter Channelyzer method. The results of these experiments showed that myocyte dimensions obtained from all three techniques were similar. The second major objective was to use the above-mentioned techniques to evaluate regional differences in myocyte size. Myocyte cross-sectional area and volume were significantly larger in the endomyocardium than in the epimyocardium of the left ventricle. Right ventricle myocytes had significantly smaller volumes and cross-sectional areas than did left ventricle myocytes. There were no regional differences in cell lengths. We conclude that the Coulter Channelyzer system gives values for isolated myocyte volume that are similar to values obtained with histometric techniques; values for isolated myocyte cross-sectional area were representative of values obtained from myocytes in whole-sectioned tissue; significant regional differences in myocyte size are present in adult rat hearts; and regional variations in myocyte size are due to differences in myocyte cross-sectional area rather than cell length.

Simulation: an evolving methodology for health administration education

Simulation provides a valuable addition to a university's teaching methods. Computer-assisted gaming is especially effective in teaching advanced business strategy and corporate policy when the nature and complexity of the simulation permit. The potential for using simulation techniques in postgraduate professional education and in managerial self-assessment appears to be significant over the next several years.

Becker's melanosis and hypoplasia of the breast and pectoralis major muscle

Becker's melanosis can be associated with hypoplastic abnormalities. In our patient (the first case report), it occurred in association with an absent pectoralis major muscle. Although more common in males, this patient demonstrates that Becker's melanosis can occur in females and may be congenital.

Marginal distortion of cast restorations induced by cementation

Eleven full veneer crowns were directly constructed on brass stylized dies. Crown marginal openings and vertical heights were measured before and after cementation with zinc phosphate cement. The following results were established. The marginal opening of complete veneer gold crowns increased during cementation. The vertical heights of well fitting crowns also increased significantly after cementation.

Failure of propranolol to prevent chronic hyperthyroid induced cardiac hypertrophy and multifocal cellular necrosis in the rat

The effect of excess thyroid and thyroid plus propranolol on right and left ventricular structure was examined. Perfusion fixed hearts from untreated adults and those treated for 10 weeks with thyroid, propranolol, and thyroid plus propranolol were embedded in plastic and sectioned for light and electron microscopy. Hyperthyroidism stimulated a significant increase in heart rate, oxygen consumption, and systolic blood pressure. Propranolol was effective in normalizing the heart rate of hyperthyroid rats, but did not affect oxygen consumption or blood pressure. Both left and right ventricular weight increased similarly in thyroid and thyroid-propranolol treated animals, but right ventricular mass increased more than left ventricular mass in both groups. The majority (21 of 24) of right ventricles from thyroid and thyroid-propranolol treated animals had multifocal areas of histologically detected fibrosis. Left ventricular fibrosis was absent or minimal in both hyperthyroid groups. Neither left nor right ventricular fibrosis was observed in control or propranolol only treated animals. We conclude that beta adrenergic stimulation is unnecessary for thyroid induced cardiomegaly, and excess thyroid hormones induce right ventricular fibrosis which is not prevented by propranolol.

Interferon reduces hepatic drug metabolism in vivo in mice

The effects of two highly purified human leukocyte interferons (IFN-A and IFN-AD) on drug-metabolizing capacity in mice have been investigated. IFN-AD was found to produce significant changes in antipyrine half-life, assessed by analysis of 14CO2 exhalation rates following 14C-antipyrine administration. By contrast, IFN-A, which has considerably less antiviral potency than IFN-AD, was found to have no effect on antipyrine half-life. The administration regimen was found to markedly alter the effects seen with IFN-AD. When IFN-AD was given as single daily doses (5 X 10(7) units/kg/day X 3 days), the half-life of antipyrine increased by a mean of 40% (from 21.0 to 28.9 min). However, when a smaller daily dose (3 X 10(7) units/kg/day) was given as a continuous infusion, the antipyrine half-life increased by more than 3-fold (from 20.8 to 68.5 min) after 3 days of administration. Continued infusion for a further 3 days produced no additional change in antipyrine half-life. These results demonstrate that human leukocyte interferons can significantly inhibit hepatic metabolic activity in vivo.

Unilateral keratosis follicularis

Unilateral keratosis follicularis is considered a localized variant of Darier's disease and should be included in the differential diagnosis of zosteriform keratotic eruptions. The authors present a case report and review the treatment; topical retinoic acid appears to be the treatment of choice.

Effect of phenobarbital on motor activity and intraventricular hemorrhage in preterm infants with respiratory disease weighing less than 1500 grams

The use of prophylactic phenobarbital to reduce motor activity and intraventricular hemorrhage was investigated in a controlled exploratory trial with 19 low birthweight premature infants with respiratory disease. Although phenobarbital significantly suppressed movement, it was associated with an increased incidence of intraventricular hemorrhage (IVH). Phenobarbital-treated infants were over eight times more likely to experience IVH than were untreated infants. These data indicate that inhibition of motor activity by phenobarbital may not alleviate the key pathogenetic factors in IVH.

Spiro[4.5] and spiro[4.6] carboxylic acids: cyclic analogues of valproic acid. Synthesis and anticonvulsant evaluation

Spiro[4.5]decane-2-carboxylic acid (12a), spiro[4.5]decane-2,2-dicarboxylic acid (11a), spiro[4.6]undecane-2-carboxylic acid (12b), spiro[4.6]undecane- 2,2-dicarboxylic acid (11b), and spiro[4.6]undecane-2-acetic acid (13) were synthesized by an improved method and evaluated for anticonvulsant activity. These analogues were synthesized to evaluate the role of the carboxylic acid group as an essential substituent in valproic acid (di-n-propylacetic acid, 1). Carbocyclic spiranes are known to resist metabolic alteration so that any activity elicited by these compounds would be due to the carboxylic acid function and not to any metabolic change. Spiro[4.6]undecane-2-carboxylic acid (12b) was the most active analogue tested and the pentylenetetrazol and picrotoxin evaluations of 12b compared favorably to 1. However, 12b failed to provide adequate protection against maximal electroshock seizures, bicuculline, or strychnine in mice. Possible reasons for these results are discussed.

Comparison of tests for the diagnosis of spontaneous encephalitozoonosis in rabbits

The effectiveness of immunofluorescence, complement fixation, microagglutination serologic tests, intradermal skin test, and detection of histologic lesions were compared for use in diagnosis of spontaneous encephalitozoonosis in rabbits. The India ink and microbead agglutination reactions were compared with immunofluorescence and complement fixation by testing 11 single or pooled sera. Serologic tests correlated best with each other and less well with intradermal tests or presence of lesions. Immunofluorescence, India ink reaction and microbead agglutination were equally useful in detecting antibodies to Encephalitozoon cuniculi. The intradermal test correlated best with the presence of detectable lesions.

Selenium concentrations in plasma of patients with arteriographically defined coronary atherosclerosis

A prospective epidemiological study (Lancet ii: 175-179, 1982) implicates low concentrations of selenium in plasma in coronary atherogenesis. We examined this relationship more directly by fluorometry of selenium in the plasma of 91 hospitalized patients who were being examined by coronary arteriography for clinical evaluation of chest pain. We observed a significant, inverse correlation between the plasma selenium and severity of coronary atherosclerosis. These results confirm those of the epidemiological studies, but the role, if any, of selenium in atherogenesis still is unclear. Its concentration in plasma is decreased by ethanol and cigarette use; possibly this is the mechanism of its relation to hypertension and atherosclerosis.

Selenium concentrations in plasma of patients with arteriographically defined coronary atherosclerosis

A prospective epidemiological study (Lancet ii: 175-179, 1982) implicates low concentrations of selenium in plasma in coronary atherogenesis. We examined this relationship more directly by fluorometry of selenium in the plasma of 91 hospitalized patients who were being examined by coronary arteriography for clinical evaluation of chest pain. We observed a significant, inverse correlation between the plasma selenium and severity of coronary atherosclerosis. These results confirm those of the epidemiological studies, but the role, if any, of selenium in atherogenesis still is unclear. Its concentration in plasma is decreased by ethanol and cigarette use; possibly this is the mechanism of its relation to hypertension and atherosclerosis.

Acyclovir for herpes simplex infections

Herpes simplex infection can appear in a wide variety of clinical presentations. The primary herpes infection can be recognized as grouped vesicles on an erythematous base which may ulcerate. Laboratory confirmation can be made by a rapid Tzanck smear or culture. When used appropriately, acyclovir is effective in treating herpes infection. The drug is available in topical and intravenous forms, and an oral form is being investigated. Acyclovir-resistant viruses have already appeared.

Teratogenicity of 2.3.7.8-tetrachlorodibenzofuran (TCDF) in mice

Treatment of pregnant C57BL/6N mice with 2,3,7,8-tetrachlorodibenzofuran (TCDF) (0, 250, 500, and 1000 micrograms/kg on gestation day 10 or 0, 10, 30, 50, and 100 micrograms/kg on gestation days 10-13) results in dose-related increases in isolated cleft palates and hydronephrotic kidneys in the offspring. TCDF is teratogenic in 100% of the fetuses at dose levels that are not maternally toxic. The fetal kidney is the most sensitive target organ but the kidney lesions may be reversible.

Chronic effects of dietary exposure to amosite and chrysotile asbestos in Syrian golden hamsters

Bioassays of amosite, short-range (SR), intermediate-range (IR) or intermediate-range chrysotile asbestos in combination with the intestinal carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were conducted with male and female Syrian golden hamsters. Amosite and both forms of chrysotile asbestos were administered at a concentration of 1% in pelleted diet for the entire lifetime of the hamsters starting with mothers of the test animals. Group sizes varied from 125-254. There was no adverse effect on body weight gain or survival by either type of asbestos or by IR chrysotile asbestos in combination with DMH. A significant increase (p less than 0.05) in adrenal cortical tumors was observed in male hamsters exposed to SR and IR chrysotile asbestos and in females treated with IR chrysotile asbestos when compared to the pooled control groups. However, statistical significance (p less than 0.05) was lost when these dosed groups were compared with temporal control groups. Neither of the male or female amosite asbestos groups showed increased neoplasia in any tissue or organ compared to the control groups. The cocarcinogen studies using IR chrysotile asbestos and 1,2-dimethylhydrazine dihydrochloride were considered inadequate because there was no increase in intestinal neoplasia in the DMH group.

Chronic effects of dietary exposure to amosite asbestos and tremolite in F344 rats

Carcinogenesis bioassays of blocky (nonfibrous) tremolite and amosite asbestos alone or in combination with the intestinal carcinogen 1,2-dimethylhydrazine dihydrochloride (DMH) were conducted with male and female Fischer 344 rats. The minerals were administered at a concentration of 1% in pelleted diet for the entire lifetime of the rats starting with the dams of the test animals. One group of amosite rats also received chrysotile asbestos via gavage during lactation. Group sizes varied from 100 to 250 animals. The offspring from mothers exposed to tremolite or amosite asbestos were smaller at weaning than those from untreated mothers and remained smaller throughout their life. The administration of dimethylhydrazine (DMH) did not affect body weight gain, either in amosite-exposed or nonexposed animals. Survival was comparable in the tremolite and control groups. The amosite-exposed rats showed enhanced survival compared to the untreated controls. DMH exposure reduced survival by approximately one year, although the amosite plus DMH groups survived slightly better than the DMH alone groups. No toxicity or increase in neoplasia was observed in the tremolite-exposed rats compared to the controls. Significant increases (p less than 0.05) in the rates of C-cell carcinomas of the thyroid and monocytic (mononuclear cell) leukemia in male rats were observed in amosite-exposed groups. However, the biological significance of the C-cell carcinomas in relation to amosite asbestos exposure is discounted because of a lack of significance when C-cell adenomas and carcinomas were combined and the positive effect was not observed in the amosite plus preweaning gavage group. The biological significance of an increased incidence of mononuclear cell leukemia is questionable, because of a lack of statistical significance in the amosite group when evaluated using life table analysis, lack of significance when compared to the tremolite control group, and the fact that no toxic or neoplastic lesions were observed in the target organs, i.e., gastrointestinal tract and mesothelium. DMH caused a high rate of (62-74%) of intestinal neoplasia in amosite and nonamosite-exposed groups. Neither an enhanced carcinogenic nor protective effect was demonstrated by exposure to amosite asbestos.