Intratemporal vascular tumors: detection with CT and MR imaging

The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion.     

The effects of a 0.12% chlorhexidine-digluconate-containing mouthrinse versus a placebo on plaque and gingival inflammation over a 3-month period

Abstract Several previous studies have evaluated the effects of 0.12% chlorhexidine digluconate (ChD) mouthrinses on plaque and gingival inflammation. However, previously, none have been based in general dental practices. The aim of this study was to evaluate the potential to conduct controlled periodontal clinical trials in co-operation with general dental practitioners (gdps). The project took place in 5 general dental practices in the South of England. 121 healthy subjects (24 at 4 sites and 25 at the 5th). aged 18-65 years, mean 35 ± 12) years participated in a double-blind, randomised study during which they received full mouth assessments for plaque and gingival bleeding at baseline, 6 and 12 weeks. 60 subjects were randomly asigned to use the 0.12% ChD mouth wash and 6i the placebo. The assessments were carried out by 5 gpds, who had previously achieved inter-examiner κ scores of 0.78–0.85 (mean 0.81) for the plaque index (PlI), and of 0.73–0.94 (mean 0.87) for a modified gingival index (mGI), and who maintained κ scores of 0.51–0.90 for PII and of 0.73–1.00 for mGI during the 12 months required to complete the study. 98 subjects (48 ChD and 50 placebo) completed the study. Even though the baseline levels of plaque and gingivitis were low, by week 12, mean whole mouth piaque score of the ChD mouthwash users had fallen from 1.33 at baseline to 0.96 and was significantly lower (p < 0.001) than for the placebo users, 1.31 at baseline to 1.13. Whole-mouth gingival bleeding score fell from 0.56 to 0.42 in the ChD mouthwash group but was unchanged (0.54–0.55) in the placebo group. A subsidiary data analysis which considered the effects at sites indicated that within these overall differences, the ChD users experienced almost 2× the reduction from plaque score 2 at baseline at proximal molar sites over a 12-week period (50.6% ChD versus 27.6% placebo). It was concluded that 0.12% ChD mouthwash reduced plaque accumulation fay 28% and gingival inflammation by 25% over a 12–week period, that it is feasible for a group of gdps to maintain high levels of inter–examiner consistency in the use of PlI and mGI, that it is also feasible to carry out such a multicentre study in general dental practice, and that the use of mean mouth scores per subject to analyse the effects of mouthrinses may well mask variations in response throughout the mouth.     

Morphometric evidence of the trophic effect of L-carnitine on human skeletal muscle

We investigated the effect of long-term i.v. administration of L-carnitine on human muscle fibers using morphometric parameters. We administered 2g/day L-carnitine to patients undergoing hemodialysis for at least 12 months. At the end of this period a marked increase in serum and muscle carnitine levels was observed in all patients, together with hypertrophy and predominance of type 1 fibers. L-carnitine was withheld for 4 months, during which time serum and muscle levels gradually decreased and no changes were observed in muscle fibers. Subsequent addition of L-carnitine to dialysis fluid for another 4 months stabilized lower levels. At the end of this period reduction of diameter of type 1 fibers was observed. Type 2 fibers remained unchanged. Moreover, type 1 fibers remained predominant in all cases. Hence, we suggest that carnitine has a specific trophic effect on type 1 fibers which are characterized by an oxidative metabolism.     

Zahlungsanspruch des externen Laborarztes unmittelbar gegen den Patienten

Abstrakt Vergibt ein behandelnder Arzt eine Laboruntersuchung an einen externen Laborarzt, kommt entweder direkt ein Vertragsverh?ltnis zwischen dem Laborarzt und dem Patienten zustande oder der Patient haftet dem Laborarzt aus den Grunds?tzen der Gesch?ftsführung ohne Auftrag.     

Densitometric and morphometric study of immunocytochemical estrogen receptors detection in breast carcinomas.

Immunohistochemical quantitative evaluation of estrogen receptors (ER) detected in tissue sections from 30 breast tumors by monoclonal antibody was performed using a densitometric method. In particular, ER concentration was calculated by nuclear mean optical density (nMOD), while heterogeneity in ER content was calculated by the coefficient of variation (CV) of the nuclear optical density histogram. Tumors which showed more than 60% of positive cells had a mean value of ER-nMOD of 0.116 +/- 0.002 a.u. and of ER-CV of 33.74 +/- 0.68. Tumors which showed 30% to 60% of positive cells had a mean value of ER-nMOD of 0.082 +/- 0.006 a.u. (arbitrary units) and of ER-CV of 36.25 +/- 3.44. Tumors showing less than 30% of positive cells had ER-nMOD of 0.052 +/- 0.009 a.u. and ER-CV of 48.49 +/- 5.61. These results indicate that the greater the concentration the lower the ER heterogeneity within the tumor sample. No significant differences between ER-ICA results, nuclear size and form factors were found.     

Charcot-Marie-Tooth phenotype produced by a duplicated PMP22 gene as part of a 17P trisomy-translocation to the X chromosome

The Charcot-Mane-Tooth disease type 1A (CMTlA) phenotype is most often associated with a 1.5 megabase (mb), tandem duplication of chromosome 17 band p12 (17˜12). The prevailing hypothesis is that the demyelinating neuropathy results from a dosage effect of the peripheral myelin protein gene PMP22 which is included within this duplication. We present a patient with clinical and electrophysiological features ofCMTlA in whom an extra PMP22 gene resulted from a rare unbalanced translocation of 17p to the X chromosome. This finding further supports the hypothesis of gene dosage as the basis for CMTlA. More-over, this case highlights the importance of fluorescence in siiu hybridization (FISH) as an alternative molecular technique in the diagnosis of CMTlA.     

Tyrosine kinase-dependent and -independent events induced by interleukin-2 stimulation: interleukin-2-mediated NO production required for the induction of lymphokine-activated killer cell activity in rat splenocytes is tyrosine kinase independent.

Nitric oxide (NO) has recently been shown to be an indispensable co-factor in the generation of lymphokine-activated killer (LAK) cells induced by interleukin-2 (IL-2). Upon stimulation with IL-2, cells endowed with specific receptors undergo phosphorylation of substrates mediated by protein tyrosine kinases (PTK). In this work we utilized a well-characterized PTK inhibitor, genistein (GEN), to address the role of PTK on NO-dependent LAK cell generation. The effects of GEN were tested on the expression of the inducible NO synthase (iNOS) gene, proliferation, generation of cytotoxic activity and production of NO upon IL-2 stimulation of rat splenocytes. We report here that GEN displays profound inhibitory effects on recombinant (r)IL-2 induced proliferation and on LAK cell generation, while only marginally affecting NO production, measured as NO2-. In contrast, a specific inhibitor of the NO synthetic pathway (NG-monomethyl-L-arginine; NMMA) blocked generation of LAK cells and NO production without affecting cell proliferation. If added directly to the cytotoxicity tests, GEN exerted minor inhibitory effects, not exceeding 25% of control tests, while NMMA was completely ineffective. Sodium nitroprusside (SNP), a non-enzymatic NO-releasing substance, restored LAK cell generation in cultures performed in the presence of NMMA, but not in those performed in the presence of GEN. These results indicate that IL-2-induced NO production is a PTK-independent event. IL-2-stimulated LAK cell generation obligatorily requires the concurrent activation of PTK dependent and independent signal transduction pathways.     

Cytokine gene expression in human peripheral blood mononuclear cells stimulated by mannoprotein constituents from Candida albicans.

The expression of cytokine genes in cultures of human peripheral blood mononuclear cells (PBMC) stimulated with mannoprotein constituents (MP) of Candida albicans has been studied by means of S1 nuclease mapping analysis, polymerase chain reaction, and enzyme-linked immunosorbent assay. MP induced early, consistent, and long-lasting production of interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha, and IL-6 mRNAs. Similar results were obtained when the same PBMC cultures were stimulated with the purified protein derivative (PPD) from Mycobacterium tuberculosis or with IL-2, although lower levels of IL-6 mRNA were detected in IL-2-stimulated cells than in MP- or PPD-stimulated cells. MP, PPD, and IL-2 induced appreciable levels of granulocyte-macrophage colony-stimulating factor and gamma interferon, but only MP and PPD were able to induce IL-2 mRNA. MP were unable to stimulate a consistent expression of the genes encoding for IL-4, IL-5, and IL-10, while low, sometimes barely detectable levels of these cytokine mRNAs were observed in PPD- or IL-2-stimulated PBMC cultures. When protein synthesis of MP-stimulated PBMC was inhibited by cycloheximide, a superinduction of mRNAs for IL-4 and IL-10 and, more markedly, gamma interferon was observed. Overall, these results highlight the powerful, selective induction of cytokine gene expression by MP constituents of C. albicans in human PBMC cultures, thus providing some functional clues to explain the efficient state of the anticandidal response in normal human subjects.