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At least 397 records · Page 22Linked to original sources
PubMed2002

Correlation between changes in apparent diffusion coefficient and induction of heat shock protein, cell-specific injury marker expression, and protein synthesis reduction on diffusion-weighted magnetic resonance images after temporary focal cerebral ischemia in rats.

OBJECT: The authors investigated the relationship between the time course of apparent diffusion coefficient (ADC) changes and stress protein induction, ischemic neuroglial damage, and cerebral protein synthesis (CPS) after temporary focal cerebral ischemia in rats. METHODS: In Group I, ADC changes were measured on magnetic resonance (MR) images obtained during the second half of a 1-hour middle cerebral artery (MCA) occlusion, during a 1-hour reperfusion, and after 23 hours of reperfusion in rats. Immunohistochemical studies for heat shock protein (hsp) 70, glial fibrillary acidic protein (GFAP), and neuronal nuclear (NeuN) protein were performed. In Group II, CPS was assessed using autoradiographic studies obtained after occlusion. At 36 minutes of occlusion, MR imaging demonstrated significantly less ADC reduction in the frontoparietal cortex (82 +/- 9% of the contralateral hemisphere) than in the striatum (64 +/- 11%; p < 0.05). After 1 hour of reperfusion, the lesion resolved and the difference between cortex and striatum was no longer evident. After 23 hours of reperfusion, the ADC lesion recurred in striatum (76 +/- 12%) compared with frontoparietal cortex (100 +/- 11%; p < 0.05). Immunohistochemical studies showed hsp 70 expression and an increased GFAP reactivity localized in the frontoparietal cortex of the ischemic hemisphere, along with a significant drop in striatal NeuN immunoreactivity. A trend toward greater reduction in striatal CPS (53 +/- 15%) than in frontoparietal cortex CPS (78 +/- 23%) was also observed. CONCLUSIONS: Sequential ADC maps correlate with the expression of neuroglial stress and injury markers after temporary focal ischemia in rats, distinguishing the striatum (infarct core) from the cortex (ischemic penumbra). A greater reduction in striatal CPS further supports the conclusion that the striatum is more susceptible to temporary MCA occlusion than the cortex.

Animals↗
PubMed2006

Influence of aqueous diffusion layer on passive drug diffusion from aqueous cyclodextrin solutions through biological membranes.

Most drugs permeate biological membranes via passive diffusion and it is generally assumed that the main barrier is the lipophilic structure of the membrane. However, we have observed that the unstirred water layer adjacent to the membrane surface can in some cases be a barrier just as effective as the lipophilic membrane itself. Hydrophilic cyclodextrins can enhance drug delivery through biological membranes by increasing the availability of dissolved drug molecules immediate to the membrane surface, i.e. by increasing drug delivery through the unstirred water layer. Cyclodextrins and drug/ cyclodextrin complexes are, in most cases, unable to permeate lipophilic membranes. Thus, excess cyclodextrin, more than is needed to solubilize the drug in the aqueous exterior, will hamper drug delivery through biological membranes.

Animals↗
PubMed2006

Single-shot, turbo spin-echo, diffusion-weighted imaging versus spin-echo-planar, diffusion-weighted imaging in the detection of acquired middle ear cholesteatoma.

Diagnosis of acquired middle ear cholesteatoma on MR imaging is mostly done on late postgadolinium T1-weighted MR images and/or echo-planar (EPI) diffusion-weighted (DWI) MR images. We describe the appearance of a case of a complicated attical middle ear cholesteatoma on single-shot (SS) turbo spin-echo (TSE) DWI compared with EPI-DWI. This case suggests a higher reliability of SS TSE-DWI in the diagnosis of acquired middle ear cholesteatoma.

Aged↗
PubMed1984

Culture of skin in diffusion chamber. Culture of whole skin in diffusion chambers in autologous rabbits: maintenance of normal epidermal differentiation.

Pieces of thinly split whole skin were placed in diffusion chambers which were implanted intraperitoneally in autologous rabbits. The condition of pretreatment of the whole skin before the intraperitoneal implantation influenced greatly its viability at the initial stage of intraperitoneal culture: The whole skin incubated at room temperature for 1 hour in phosphate buffered saline containing 1 microgram/ml hydrocortisone could maintain almost completely the original structure of its epidermis showing complete keratinization successively as in vivo; without hydrocortisone in phosphate buffered saline, the culture resulted in degeneration of upper epidermis of the whole skin; meanwhile, the quick treatment of the whole skin with the buffer containing no hydrocortisone within 10 min resulted in partly slight parakeratosis. In the course of culture, new epidermis was formed under degenerated upper epidermis, showing complete keratinization. Epidermis could maintain nearly the original structure as long as 4 weeks of culture, however at 6 and 8 weeks of culture, it appeared flattened and partly degenerated. It was noticeable that in some part, the epidermal outgrowth formed directly on the filter showed complete keratinization.

Animals↗
PubMed1975

Anti-immunoglobulin analysis by diffusion patterns of inhibition and facilitation of complementary lysis in agar. II. Diffusion-lysis as a method for recognizing in vivo immunosuppressive activity of anti-immunoglobulins.

This paper provides evidence that it is possible to prepare facilitating anti-mouse immunoglobulin (that is, anti-mouse immunoglobulin which facilitates complementary lysis of red cells sensitized with mouse-produced haemolysin) which, when injected into mice 24 hours before an injection of sheep red cells, very markedly reduced the number of haemolysin-producing cells detectable in spleen four days later. The diffusion-lysis method was used to recognize this and other anti-Ig's in heterologous antiserum and fractions thereof. The effective antibody was in the gamma2 fraction of antiserum produced in guinea pigs by injecting them with guinea pig red cells sensitized with mouse-produced haemolysin. This method of immunizing was used in order to stimulate the production of antibody against immunoglobulin which had undergone the configurational change characteristically occurring when antibody unites with antigen. The 19S fraction of the antiserum contained inhibiting anti-mouse immunoglobulin (anti-mouse immunoglobulin which inhibits complementary lysis of red cells sensitized with mouse-produced haemolysin) and interfered with immune depression by the gamma2 fraction. It is postulated that the gamma2 fraction induces complementary lysis only of lymphocytes whose surface immunoglobulin receptors have bound antigen and undergone configurational change. It is suggested that facilitating anti-immunoglobulin of the type described is responsible for immune suppression by anti-lymphocyte serum (ALS). Facilitating anti-mouse immunoglobulin was demonstrated in two samples of ALS (anti-mouse) which were active in suppressing graft rejection, but inhibiting anti-mouse immunoglobulin only was found in a sample which was ineffective in suppressing graft rejection.

Agar↗
PubMed1992

Diffusion-perfusion inhomogeneity and alveolar-arterial O2 diffusion limitation: theory.

Unequal distribution of pulmonary O2 diffusing capacity (D) to pulmonary blood flow (Q) (D/Q heterogeneity) leads to decreased alveolar O2 exchange efficacy. It is shown on simple models that the effect increases with increasing amount of inequality and with increasing value of the equilibration index, D/(Q beta) (beta, increment in blood O2 content per partial pressure increment). This inhomogeneity effect, if not taken into account, leads to spurious increases of D in hypoxia and with elevated O2 uptake.

Animals↗
PubMed1985

Effects of neurosurgical treatment on diffuse slow spike and wave complex: a case of left frontal mass lesion with diffuse slow spike and wave complex (DSSW).

A 10-year-old girl with a mass lesion in the left deep frontal lobe was reported. Clinically, seizures occurred at 3 years and 8 months and became intractable around the age of 5.5 years. EEG initially showed focal spikes on the left fronto-central area and later developed into diffuse slow spike and wave complexes (DSSW). Her seizures were clinically different from those in Lennox-Gastaut syndrome. After a left frontal lobectomy, her intractable seizures completely disappeared with marked EEG improvement and without any neurological deficit. Radiological findings before the operation suggested that the expanding effects extended to the deep temporal structures, adjacent to the frontal lobe. These structures, deep frontal and temporal lobes, both or either, were assumed to be involved in generating DSSW in this case.

Child↗
PubMed2005

Activity of Bulgarian propolis against 94 Helicobacter pylori strains in vitro by agar-well diffusion, agar dilution and disc diffusion methods.

Propolis exhibits antimicrobial, anti-inflammatory and other biological effects. The aim of this study was to evaluate the activity of 30 % ethanolic extract of Bulgarian propolis against 94 Helicobacter pylori strains by three methods. By the agar-well diffusion method, only 13.8 % of the strains exhibited no inhibition by 30 microl propolis extract (containing 9 mg propolis) and all isolates were inhibited to some extent by 90 microl of the extract (27 mg propolis) per well. The mean diameters of growth inhibition by 30, 60 or 90 microl propolis extract or 30 microl 96 % ethanol per well were 16.8, 19.2, 27.5 and 8.3 mm, respectively. The propolis extract was more active than the ethanol (P < 0.001). With 90 microl propolis extract per well, 69.4 % of the strains exhibited large diameters of growth inhibition (> or =20 mm) versus 26.6 % with 30 mul per well (P < 0.001). With moist propolis discs, inhibition was detected in more strains (92.1 %) than with dried discs (78.2 %, P < 0.05), with mean inhibitory diameters of 18.7 and 13.8 mm, respectively. By the agar dilution method, 100 and 300 microg propolis ml(-1) inhibited the growth of 57.1 % and 76.2 %, respectively, of the 21 strains tested. In conclusion, Bulgarian propolis had a strong and dose-dependent activity against most of the H. pylori strains tested. Although the effect of propolis on H. pylori in vitro is promising, further microbiological, pharmacological and clinical trials are required.

Agar↗
PubMed1981

Elimination of extracranial blood flow during dynamic cerebral perfusion studies using diffusible and non-diffusible radioisotope.

The extracranial blood flow seriously complicates the interpretation of dynamic cerebral studies. To eliminate this, we used a blood pressure cuff placed around the head in 50 patients with no evidence of cerebrovascular disease. The pressure in the headband was increased to 30 mmHg above the patient's systolic pressure, and the first 60 sec static scintigram was taken exactly 3 min after the injection of 99mTc-pertechnetate. A second 60 sec static scintigram was taken without pressure in the headband at 6 min after injection. After correction for diffusion of tracer into extravascular compartments we could still show 13% reduction in counting rates over the hemispheric regions and 30% over the convexity regions during application of the pressure headband. With the Xenon method, the application of the headband appears to have insignificant influence on the results of cerebral perfusion. We thus recommend that a headband should be used for dynamic 99mTc-isotope cerebral circulation studies.

Cerebrovascular Circulation↗
PubMed2007

Correlation of Neo-Sensitabs tablet diffusion assay results on three different agar media with CLSI broth microdilution M27-A2 and disk diffusion M44-A results for testing susceptibilities of Candida spp. and Cryptococcus neoformans to amphotericin B, caspofungin, fluconazole, itraconazole, and voriconazole.

We compared the Neo-Sensitabs tablet assay to both reference M27-A2 broth microdilution and M44-A disk diffusion methods for testing susceptibilities of 110 isolates of Candida spp. and Cryptococcus neoformans to amphotericin B, caspofungin, fluconazole, itraconazole, and voriconazole. Neo-Sensitabs assay inhibition zone diameters in millimeters on three agars (Mueller-Hinton agar supplemented with 2% dextrose and 0.5 microg/ml methylene blue [MGM], Shadomy [SHA], and RPMI 1640 [RPMI, 2% dextrose]) were obtained at 24 to 72 h. The correlation coefficient of Neo-Sensitabs results with MICs was similar to that of the disk method for most of the five agents on MGM (R, 0.80 to 0.89 versus 0.76 to 0.89, respectively). Overall, superior correlation was observed at 24 h for most agents. The exception was amphotericin B (R values of 0.68 and 0.5 for disk and tablet, respectively, at 48 h versus 0.68 and 0.48, respectively, at 24 h). In general, Neo-Sensitabs results were less consistent on SHA and RPMI agars. Although agreement by breakpoint category of Neo-Sensitabs and disk results with CLSI method M27-A2 was also similar on MGM (92.7 to 98.2% versus 95.5 to 100%, respectively), the Neo-Sensitabs method failed to identify two of the six isolates with high amphotericin B MICs. These data suggest the potential value of the Neo-Sensitabs assay for testing at least four of the five agents against yeasts evaluated in the clinical laboratory.

Amphotericin B↗
PubMed1994

[Diffuse sclerosing papillary carcinoma of the thyroid gland. Apropos of a pediatric case of association of an unilateral tumor with diffuse lymphocytic thyroiditis].

A 11-year-old girl presented in 1990 with bilateral goiter, hypothyroidism and thyroid auto-antibodies and was treated for Hashimoto's thyroiditis. In 1991, a cervical lymph node metastasis revealed diffuse sclerosing papillary carcinoma (DSPC) of the right thyroid lobe and chronic lymphocytic thyroiditis of the left lobe. The patient is in remission in 1993 (total follow-up, 39 months). The review of 60 previously reported cases of DSPC shows a predilection for young people, a high incidence of lymph node and pulmonary metastases; however the mortality rate is quite low, reflecting either the good prognosis linked to a young age in papillary thyroid carcinomas, or the short duration of the follow-up preventing assessment of the behaviour of DSPC.

Carcinoma, Papillary↗