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Biomedical subjects

M Abram

Publications and source records attributed to M Abram.

14 recordsLinked to original sources
PubMed2002

Influence of calcium hydroxide root-canal sealer on microbial growth in vitro.

The calcium hydroxide-based filling material Apexit, which is often used in endodontic practice, was evaluated for its antibacterial and antifungal effects against microorganisms isolated from oral cavity (Serratia marcescens, Pseudomonas putida, Staphylococcus aureus, Candida albicans). Two different quantitative techniques were employed--the direct-contact test was used to examine the efficacy of freshly mixed material while the broth-survival test was employed to check the antimicrobial properties of 5-d-old material. Apexit inhibited Gram-negative bacteria more effectively than Gram-positive ones but had none or a very weak inhibitory effect on C. albicans.

Anti-Bacterial Agents↗
PubMed2000

Plasma cytokine response in mice with bacterial infection.

BACKGROUND: Exposure to microorganisms elicts the production of cytokines. These soluble factors enhance several innate immune functions and regulate the ensuing specific immune response aimed at limiting the spread of infection. AIM: This study was undertaken to quantify the plasma levels of pro-inflammatory cytokines during the course of primary Listeria monocytogenes and Campylobacter jejuni infection. Using an in vivo infection the relationship between endogenous cytokines and the bacterial number in the liver of infected animals was examined. METHODS: C57BL/6 mice were infected by the intraperitoneal route. At different time points we determined the number of colony-forming units of bacteria in the liver of infected animals and paralled these with the plasma levels of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) measured by enzyme immunoassays. RESULTS: L. monocytogenes infection lasted 10-11 days. IFN-gamma production occurred in the early phase but was more pronounced after day 4, following the appearance of specific immunity. The duration of experimental campylobacteriosis was 15 days. Early IFN-gamma production was not significant but a progressive rise of this cytokine in plasma was seen during the second week post infection. Mice produced measurable amounts of plasma TNF-alpha immediately after being given viable L. monocytogenes, peaking on day 2-3 when the greatest number of bacteria was present in the examined organs. During C. jejuni infection plasma TNF-alpha was produced in a similar manner, but the highest concentrations were found a few days later than in listeriosis, in correlation with the different course of campylobacteriosis. The quantity of IL-6 increased and decreased in concordance with clearance of L monocytogenes and the clinical status of the animals. C. jejuni did not promote the induction of this cytokine. This is to some extent an unusual finding. With respect to the role of IL-6 in Th2 responses and antibody production, the appearance of this cytokine in campylobacteriosis was more expected. DISCUSSION: During systemic bacterial infection, a network of pro-inflammatory cytokines is activated and blood levels of these cytokines are elevated, albeit inconsistently, with large individual variations and depending on microbial characteristics and structure.

Animals↗
PubMed1998

Primary Campylobacter jejuni infection in different mice strains.

Campylobacter jejuni is one of the most frequent causes of diarrhoea in man. Extra-intestinal manifestations may also occur, particularly in immunocompromised individuals. However, because of the lack of appropriate animal models the pathophysiology and immunological response of the host to C. jejuni infection are still poorly understood. In our laboratory an experimental infection of adult BALB/c, C57BL/6 and DBA/2 mice has been established. After intraperitoneal injection of 0.5-1x10(9) cfu of C. jejuni none of the infected mice showed clinical symptoms of illness, but bacterial spreading and tissue invasion were achieved. We have concentrated our studies on the duration of primary infection, recovery of bacteria from livers and spleens of infected animals and pathohistological changes of these organs. Our results showed differences in the course of systemic infection among the tested mice strains. BALB/c mice were most sensitive, resulting in the most pronounced pathohistological changes in the examined organs. The duration of the primary liver infection was the longest in BALB/c mice while the duration of the splenic infection also differed among the tested mice strains. Nevertheless, the experimental model used in this study can be efficiently used in further analysis of the pathogenesis of this bacterial infection. However, the strain differences should be taken into account depending on the parameters to be followed.

Animals↗
PubMed1997

Primary Listeria monocytogenes infection in gestating mice.

The facultative intracellular Gram-positive bacterium Listeria monocytogenes is a food-borne pathogen of frequently underestimated importance. Pregnant women represent the high-risk group for L. monocytogenes infection. Abortion, stillbirth or neonatal infection can be the serious outcome of such an infection. Recovery from listeriosis, resistance mechanisms of the host and the effect of L. monocytogenes on fetal development still remain to be fully understood. The results of our experiments showed an increased susceptibility of gestating BALB/c mice to primary L. monocytogenes infection. The duration of listeriosis in gestating animals was almost twice longer than in the control group. Furthermore, it was clearly shown that the detrimental effect of L. monocytogenes on fetal development was more pronounced if the infection was acquired earlier during gestation.

Animals↗
PubMed1993

[The role of adrenal gland x-ray computed tomography and scintigraphy using radiolabelled norcholesterol in the etiological diagnosis of primary hyperaldosteronism].

The major etiologies of primary aldosteronism are aldosterone-producing adrenal adenoma, requiring a surgical treatment, and bilateral hyperplasia, usually managed with medical therapy. We only report a retrospective study on 22 patients with primary aldosteronism diagnosed by clinical and usual biochemical tests. All the patients were explored by computed tomography scan (CT) and iodomethyl-norcholesterol scintigraphy. The purpose of this study was to compare the capacity of the two methods to differentiate adrenal adenoma and hyperplasia. The CT scan was more sensitive (sensitivity: 88%) compare to scintigraphy (sensitivity: 64%) for the diagnosis of adrenal adenoma. However, the scintigraphy was a useful tool to detect asymmetric macronodular adrenal hyperplasia. Therefore, the catheterisation of adrenal venous would be only necessary for a few cases. We conclude from this study and the literature review that CT scan and iodomethyl-norcholesterol scintigraphy are complementary and both useful to increase diagnostic reliability of primary aldosteronism.

19-Iodocholesterol↗
PubMed1993

Antimicrobial activity and immunological side effects of different antibiotics.

Antibiotics, in addition to killing or inhibiting the growth of microorganisms, may also affect the immune response in many ways. Such effects may be clinically relevant especially when an impairment of immunological functions is seen. This study was designed to analyse the influence of various groups of antibiotics on the host defence system by using different tests in vitro on human or animal cells and in vivo on an animal model. At the same time we analysed the antimicrobial effectiveness of the same antibiotics on over 2800 bacterial strains isolated from our clinical material. Preliminary findings show that a correlation exists between the effect of antibiotics on the immune response, especially the humoral response, and the appearance of resistance in bacteria to these antibiotics.

Animals↗
PubMed1992

[Pituitary tumor syndrome and hyperprolactinemia in peripheral hypothyroidism].

We studied 7 women with primary hypothyroidism who were suspected to harbor a prolactinoma on the basis of a pituitary gland enlargement associated with hyperprolactinemia. The diagnosis of prolactinoma was confirmed in 1 case only, which was treated surgically. In the remaining 6 patients the serum prolactin levels fell to normal on thyroxine replacement therapy and reduction in size of the pituitary gland was demonstrated by neuroradiological imaging in the 3 documented cases. This study underlines the fact that hyperprolactinemia associated with pituitary hyperplasia is secondary to hypothyroidism and that thyroid function tests should be obtained in all hyperprolactinemic patients even those with pituitary enlargement.

Adult↗
PubMed1987

Effect of the endodontic status of the tooth on experimental periodontal reattachment in baboons: a preliminary investigation.

The effect of the endodontic status of the tooth on periodontal reattachment after the raising of a mucogingival flap was studied with the use of 48 teeth in four old baboons. Root canal therapy was performed on 26 front teeth. Tubliseal, AH26, N2, and Diaket were used as sealers with gutta-percha. The pulps of 5 teeth were exposed and left infected; 17 teeth with intact pulps served as a control. The teeth and their surrounding structures were studied histologically for reattachment with new cementum formation 2 to 17 days, 1 to 2 months, and up to 1 year after the operation. In the teeth examined 1 month postoperatively or more, if epithelium had not covered the denuded surface, new cementum was present, regardless of the endodontic status.

Animals↗
PubMedDate not supplied

Euglobulin lysis times: an update.

UNLABELLED: There are several clot lysis tests available to assess the presence of increased fibrinolysis in a clinical situation. These include whole blood, plasma, and "eugloblin" lysis tests. The euglobulin lysis test (ELT) is actually a modified plasma clot lysis time, which detects increased plasminogen activation and subsequent fibrinolysis. It does not detect the activity of antiplasmins. The purpose of this study was to determine ELT for a group of 25 ambulatory normals. There were 10 males and 15 females, ranging in age from 25 to 56 years. Citrate anticoagulated samples were obtained immediately after application of a tourniquet and 10 minutes after application of a sphygmomanometer inflated to midway between systolic and diastolic pressure. The citrated plasma was precipitated with cold acetic acid. The precipitate contained fibrinogen, plasminogen, and plasminogen activators, with fibrinolytic inhibitors theoretically removed. The precipitate was redissolved and the euglobulin solution was clotted with thrombin. The clotted sample was then incubated at 37 degrees C and was observed at 10 minute intervals for clot lysis. RESULTS: The reference range of onset of fibrinolysis was from 1.25 to 12 hours, with a mean of 3.78 hours +/- 2.45 hours (1 S.D.). Venostasis (use of the sphygmomanometer) resulted in an ELT that was shorter than the non-venostasis specimens in 11 of 25 specimens. This is thought to be secondary to in vivo activation of plasminogen. CONCLUSION: The average euglobulin lysis time in 25 ambulatory normals is approximately 3.5 hours. The ELTs vary over a broad range (1.25 to 12.0 hours) in normal ambulatory volunteers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗