Detection of Francisella tularensis in ulcers of patients with tularemia by PCR.

The diagnosis of human cases of tularemia is usually confirmed by the demonstration of an antibody response to Francisella tularensis, which occurs about 2 weeks after the onset of disease. Due to a high risk of infection in the laboratory, cultivation of the causative agent tends to be avoided. During an outbreak in Sweden, the use of PCR for diagnosing the ulceroglandular form of tularemia was evaluated. Extraction and preparation of F. tularensis DNA from swab samples from the wounds of patients with tularemia involved the use of the nuclease inhibitor guanidine thiocyanate. The DNA was detected by multiplex PCR targeting the 16S rRNA gene and a 17-kDa lipoprotein gene of F. tularensis. In 29 of 40 (73%) patients with serologically confirmed tularemia, F. tularensis DNA was successfully amplified. Considering the limitations of current diagnostic procedures, PCR may become useful for the early diagnosis of tularemia.     

The use of isolated fish opercular epithelium as a model tissue for studying intrinsic activities of loop diuretics

Isolated opercular epithelia of killifish (Fundulus heteroclitus) were mounted in an Ussing chamber. The epithelia displayed a transepithelial electrical potential difference (PD) of 10.6 +/- 0.3 mV (sea-water side negative) and a short-circuit current (SCC) of 72.1 +/- 2.1 microA cm-2. The electrical resistance was 160 +/- 3 omega cm2 (mean +/- SE, n = 269). The unidirectional flux of 36Cl from blood side to sea-water side compared well with the SCC. No net flux of 22Na or 24Na across the epithelium was observed. Raising of cyclic AMP levels by theophylline, 3-isobutyl-I-methyl-xanthine, isoprenaline and forskolin, increased SCC and PD. Prostaglandins PGE2 and to some extent PGF2 alpha inhibited SCC and PD. Inhibition of Na+-K+-ATPase by ouabain and orthovanadate reduced SCC and PD. Pretreatment of the epithelium with the stilbene disulphonic acid (DIDS) did not prevent the action of orthovanadate. Different types of diuretics were tested, but only the loop diuretics bumetanide, piretanide, and furosemide, rapidly and strongly inhibited PD and SCC and unidirectional 36Cl serosal to mucosal flux. Dose-response curves for these agents were parallel and EC50 values for effects on SCC were 40, 52, and 295 microM, respectively. The same relative activities of these diuretics have been seen in the renal thick ascending limb of Henle's loop (TALH). It is concluded that the killifish opercular skin responds to hormonal stimuli and various pharmacological agents in a manner similar to that of mammalian renal TALH. It should therefore be a useful model for studies of the modes of action and the structure-activity relationships of diuretics which act by inhibition of chloride transport or Na+-K+-ATPase activity.     

Aldehyde dehydrogenase activities in hepatocyte nodules and hepatocellular carcinomas from Wistar rats

The activities of aldehyde dehydrogenases using benzaldehydeand propionaldehyde as substrates and NADP and NAD as coenzymeswere determined in normal liver, hepatocyte nodules and hepatocellularcarcinomas from male Wistar rats. Hepatocyte nodules were producedby intermittent exposure of rats to 0.05% 2-acetylaminofluoreneor by initiation with diethylnitrosamine followed by selectionusing 2 weeks of dietary exposure to 0.02% 2-acetylaminofluoreneand partial hepatectomy. The activities of propionaldehyde:NAD and benzaldehyde: NADP aldehyde dehydrogenases were increasedin hepatocyte nodules of all types as well as in most hepatocellularcarcinomas. The most prominent elevation of enzyme activitywas found in the cytosol of persistent hepatocyte nodules (35–60times) and some hepatocellular carcinomas (92 times) using benzaldehydeand NADP. The benzaldehyde: NADP aldehyde dehydrogenase activityvaried considerably between different nodules suggesting theexistence of a subpopulation of hepatocyte nodules with veryhigh enzymatic activities. The activity of propionaldehyde:NAD aldehyde dehydrogenase activity as well as of -glutamyltransferasedid not show substantial internodular variations. The activityof benzaldehyde: NADP aldehyde dehydrogenase in individual carcinomasinvestigated in these experiments varied extensively. The datadid not support the idea that all hepatomas had been developedfrom pre-neoplastic nodules with very high activity of thisenzyme.     

Infusion of ornithine-alpha-ketoglutarate in healthy subjects: effects on protein metabolism

Infusion of ornithine-alpha-ketoglutarate (Ornicetil) has been suggested to improve nitrogen balance in trauma patients. Whether this anticatabolic effect is localised to the liver or to skeletal muscle is as yet unknown. Consequently, the splanchnic and leg exchange of amino acids, urea and ammonia were measured in seven healthy non-obese subjects in the basal state and during infusion of ornithine-alpha-ketoglutarate at a rate of 28 mg/min for 150 min. The results demonstrate a six-fold rise in arterial ornithine and an increased uptake by both splanchnic and leg tissues during infusion. The splanchnic uptake of threonine and lysine also increased, while no other alterations were seen in leg amino acid exchange. The arterial urea concentration decreased slightly (-6%, P<0.01) during the infusion in spite of an unchanged urea production from the liver. The ammonia concentration fell by 20% (P<0.05), while glycerol and ketone body concentrations did not change significantly. It is concluded that intravenous infusion of ornithine-alpha-ketoglutarate in healthy subjects does not significantly influence hepatic or skeletal muscle protein metabolism.     

Growth hormone modifies the growth rate of enzyme-altered hepatic foci in male rats treated according to the resistant hepatocyte model

Male and female Wistar rats were given an initiating i.p. injectionof diethylnitrosamine (DEN; 200 mg/kg body wt). Two weeks laterthe rats were given a diet containing 0.02% (w/w) 2-acetylaminofluorene(2-AAF) for 2 weeks. In the middle of the 2-AAF treatment a70% partial hepatectomy (PH) was performed. In order to identifythe pituitary hormone responsible for the previously observedsex difference (male > female) in and influence of ectopicpituitary grafts on focal growth during 2-AAF/PH selection ofenzyme-altered foci, male rats were treated with a continuousinfusion of bovine growth hormone (bGH; 6 µg/h) or ovineprolactin (oPrl; 6 µg/h) by way of osmotic minipumps.Hormonal treatment was started 1 week after initiation and wasfinished 1 week after the 2-AAF selection period. All rats werekilled 6 weeks after initiation and liver sections were stainedfor -ghitamyttransferase. The number of foci/cm² as well asthe area per focus and area ratio (mm² foci/cm² liver section)were calculated. Whereas no significant differences in the numberof foci /cm² were observed between the different groups of rats,bGH treatment of male rats decreased both the area/focus andthe area ratio down to the female level. No significant effectswere seen following oPrl administration when compared with controlmales. In vitro studies of subcellular preparations from theliver lobes obtained at PH showed that the sexually differentiatedN-hydroxy-2-AAF sulfotransferase activity (male > female)in male rats was ‘feminized’, i.e. decreased, bybGH administration, but not by infusion of oPrl. The presentinvestigation strengthens the view of growth hormone as an importantdeterminant of sex differences in chemical carcinogenesis inrat liver, possibly via an influence on carcinogen metabolism.     

Randomized trial of oral naproxen or local injection of betamethasone in lateral epicondylitis of the humerus

A randomized pilot study, comparing oral naproxen and a single betamethasone injection, was carried out in 21 patients suffering from lateral epicondylitis of the humerus ("tennis elbow"). The naproxen dosage was 250 mg per day for two weeks. Six milligrams of betamethasone in a long-acting form was given as a local injection. To achieve "blindness," the patients receiving naproxen were also given an injection of saline into the area of maximal tenderness at the epicondyle, while the patients getting the betamethasone-injection were given oral placebo tablets. At a clinical control after two weeks, five of the ten patients receiving naproxen and five of the 11 patients receiving betamethasone injection were improved. Thus, no apparent difference in effect could be noted at an evaluation after two weeks' treatment. No significant side effects were noted with any of the treatments.     

Stereoselective inhibition of monoamine oxidase and semicarbazide-sensitive amine oxidase by 4-dimethylamino-2,α-dimethylphenethylamine (FLA 336)

Summary The in vitro inhibition by amiflamine [FLA 336(+)] and related compounds of the activity of rat monoamine oxidase (MAO)-A and-B, rat semicarbazide sensitive amine oxidase (SSAO) and human platelet poor plasma benzylamine oxidase was studied. Amiflamine was an MAO-A selective inhibitor, but also inhibits SSAO with both a reversible (competitive, K _i=200 mol/l) and a small time-dependent component which was irreversible in nature. The optical isomer FLA 336(–) was ten times less potent towards MAO-A. However, this compound was much more potent an inhibitor of SSAO (competitive, K _i=4.6 mol/l). The amiflamine metabolites FLA 788(+) and FLA 668(+) inhibited SSAO, but only at concentrations considerably higher than required for MAO-A inhibition. Ex vivo experiments indicated that there was no significant irreversible inhibition of rat heart and lung SSAO after both single and repeated administration of amiflamine at doses up to 20 times higher than required for inhibition of MAO-A within central serotoninergic neurones.     

On mechanisms of sex differences in chemical carcinogenesis: effects of implantation of ectopic pituitary grafts on the early stages of liver carcinogenesis in the rat

The resistant hepatocyte model was used to investigate the influenceof pituitary factors on the early events of chemical carcinogenesisin rat liver. Diethylnitrosamine (DEN), 200 mg/kg body weight,was used as an initiator of enzyme altered foci. Two weeks afterinitiation the rats were placed on a 0.02% (w/w) 2-acetylaminofluorene(2-AAF) diet for two weeks. Partial hepatectomy (70%) was performedthree weeks after initiation. The rats were killed four to sixweeks after DEN initiation. Sex differences in area/foci aswell as in area ratio (mm² foci/cm² liver section) were foundin liver sections from sexually mature male and female rats( > ) of both the Sprague-Dawley and Wistar strains. Ectopicpituitary grafts (PG: s) implanted under the kidney capsuleof male Wistar rats one week before DEN initiation and removedby unilateral nephrectomy one week after initiation did notinfluence the number or area of enzyme altered foci as comparedwith sham operated male rats. On the other hand, PG:s implantedone week before 2-AAF selection in male Wistar rats and allowedto remain until the rats were killed two weeks after the 2-AAFselection period, decreased the area ratio to a level closeto that of sham operated female rats, whereas no effect on thenumber of enzyme altered foci was found. The results suggestthat the hypothalamo-pitu-itary axis may be involved in theregulation of early stages of liver carcinogenesis.     

Engineered NS1 for Sensitive,Specific Zika Virus Diagnosis from Patient Serology

Dengue virus (DENV) and Zika virus (ZIKV) belong to the Flaviviridae family of viruses spread by Aedes aegypti mosquitoes in tropical and subtropical areas. Accurate diagnostic tests to differentiate the 2 infections are necessary for patient management and disease control. Using characterized ZIKV and DENV patient plasma in a blind manner, we validated an ELISA and a rapid immunochromatographic test for ZIKV detection. We engineered the ZIKV nonstructural protein 1 (NS1) for sensitive serologic detection with low cross reactivity against dengue and developed monoclonal antibodies specific for the ZIKV NS1 antigen. As expected, the serologic assays performed better with convalescent than acute plasma samples; the sensitivity ranged from 71% to 88%, depending on the performance of individual tests (IgM/IgG/NS1). Although serologic tests were generally less sensitive with acute samples, our ZIKV NS1 antibodies were able to complement the serologic tests to achieve greater sensitivity for detecting early infections.