Phase behaviour of n-hexane/perfluoro-n-hexane binary thin wetting films.

We present X-ray reflectivity investigations of the concentration distribution in binary liquid thin films on silicon substrates. The liquid-vapor coexistence of the binary mixture investigated, hexane and perfluorohexane, is far from criticality. Therefore, a sharp interface separates the liquid film from the vapor. The data reveal a separation of the film in layers parallel to the substrate. A phase diagram is constructed as a projection to the (composition difference, temperature) space, covering a temperature range corresponding to the one-phase and the two-phase regime of the bulk liquid. Although the composition data indicate a mixing gap similar to that of the bulk system, there are two major differences: i) only the near-surface phase changes its composition significantly, and ii) a composition gradient in the film exists also at higher temperatures where in the bulk system the one-phase regime exists.

Influence of rifampin on serum markers of cholesterol and bile acid synthesis in men.

OBJECTIVE: It has been demonstrated in preliminary studies that rifampin, a semisynthetic antibiotic and known inducer of hepatic cytochrome P450 3A4, reduces serum concentrations of total bile acids only in individuals with liver disease and elevated serum bile acid levels. METHODS: We studied the effect of rifampin on concentrations of surrogate serum markers of cholesterol and bile acid synthesis as well as of cholesterol absorption in 10 male subjects before and after administration of rifampin (600 mg/day) for 6 days. Cholesterol and its precursors were analyzed by gas-liquid chromatography (GLC), bile acid intermediates and individual bile acids by isotope-dilution methods using GLC-mass spectrometry (MS) or by high-performance liquid chromatography (HPLC). RESULTS: Treatment with rifampin resulted in a 70% increase (p = 0.008) of the serum concentration of the bile acid precursor 7alpha-hydroxy-4-cholesten-3-one, which is a marker for bile acid production. Serum total cholesterol was not altered, however, treatment with rifampin elevated the ratio of lathosterol to cholesterol, an indicator of cholesterol synthesis, by 23% (p = 0.037). Interestingly, serum concentration of total bile acids decreased slightly by 29% (p = 0.022), mainly due to a lowering of the secondary bile acid, deoxycholic acid (-60%; p = 0.005). CONCLUSION: A 6-day treatment with rifampin induces a reduction of deoxycholic serum concentrations in healthy men associated with a moderate increase of serum markers of bile acid and endogenous cholesterol synthesis.

[Evaluation of her-2/neu amplification/overexpression in OSCC with fluorescence in situ hybridization (FISH) and immunohistochemistry]. / Uberexpression/Amplifikation des her-2/neu-Protoonkogens in oralen Plattenepithelkarzinomen.

INTRODUCTION: The human epidermal growth factor receptor ( her-2/ neu) protooncogene encodes a membrane tyrosine kinase with homology to the epidermal growth factor receptor (EGFR). Amplification and protein overexpression have been identified in various solid tumors and a significant association with poor clinical outcome was reported. This investigation was performed to assess the frequency of her-2/ neu overexpression and to compare these results with clinical outcome in OSCC. MATERIAL AND METHODS: Archival biopsy specimens from 97 untreated OSCCs were evaluated using a polyclonal antibody A0485 (Dako). Only membrane staining intensity and pattern were evaluated according to the guidelines of the clinical trial assay recommendations (0-3+) for breast carcinoma. Score 0 and 1+ were interpreted as negative for HER-2/NEU protein overexpression and 2+ and 3+ as positive. FISH analysis with directly labeled probes for her-2/ neu and chromosome 17 was performed on the same specimens. The ratio between her-2/ neu and chromosome 17 signals was calculated after selection of 20-40 non-overlapping tumor cells. The tumor was considered amplified if the ratio was above 2. RESULTS: In 11 out of 97 biopsies (11.3%) membranous overexpression (score 2+ and 3+) of her-2/ neu was shown by immunohistochemistry. FISH analysis in 42 cases revealed amplification in 14 cases. Concordance between immunohistochemistry and FISH was found in 86%. Clinical-pathological data as well as survival revealed no correlation with her-2/ neu status. DISCUSSION: In spite of missing correlation between survival and her-2/ neu overexpression in our study, the predictive value of the her-2/ neu protooncogene in adjuvant therapy in OSCC needs further investigation.

[Definition of shock types]. / Definitionen der Schockformen.

Definitions of shock types. Hypovolaemic shock is a state of insufficient perfusion of vital organs with consecutive imbalance of oxygen supply and demand due to an intravascular volume deficiency with critically impaired cardiac preload. Subtypes are haemorrhagic shock, hypovolaemic shock in the narrow sense, traumatic-haemorrhagic shock and traumatic-hypovolaemic shock. Cardiac shock is caused by a primary critical cardiac pump failure with consecutive inadequate oxygen supply of the organism. Anaphylactic shock is an acute failure of blood volume distribution (distributive shock) and caused by IgE-dependent, type-I-allergic, classical hypersensibility, or a physically, chemically, or osmotically induced IgE-independent anaphylactoid hypersensibility. The septic shock is a sepsis-induced distribution failure of the circulating blood volume in the sense of a distributive shock. The neurogenic shock is a distributive shock induced by generalized and extensive vasodilatation with consecutive hypovolaemia due to an imbalance of sympathetic and parasympathetic regulation of vascular smooth muscles.

Absence of therapeutically relevant c-erbB-2 expression in human hepatocellular carcinomas.

c-erbB-2 (Her-2/neu) represents a well established prognostic marker and therapeutic target in several human tumor types, especially breast cancer. Its potential role in hepatocellular carcinoma (HCC) has not yet been characterized. Using standardized immunohistochemical procedures, we have analyzed the c-erbB-2 expression in a representative panel of human HCCs. Our data demonstrate the absence of significant membranous expression or cytoplasmic overexpression. Thus c-erbB-2 is neither a prognostic marker nor a relevant therapeutic target in human HCCs.

Significance of high-grade prostatic intraepithelial neoplasia in needle biopsy specimens.

OBJECTIVES: To examine the significance of high-grade prostatic intraepithelial neoplasia (HGPIN) in biopsy specimens. METHODS: We performed sextant biopsies on a series of 83 cystoprostatectomy specimens removed for bladder cancer. For each case the number of foci and volume of both HGPIN and prostate cancer were assessed in the prostatectomy specimens and compared with the number of biopsy specimens involved by HGPIN. RESULTS: We identified HGPIN in 82 (99%) of 83 prostatic glands, whereas prostate cancer was found in 41 cases (49%). Corresponding sextant biopsies harbored both HGPIN and prostate cancer in 6 cases (7%), whereas only HGPIN was diagnosed in 29 sextant biopsies (35%). There was a positive correlation between the number of biopsy specimens containing HGPIN and the volume and multifocality of HGPIN in the corresponding prostatic glands. Prostates with HGPIN on sextant biopsy contained prostate cancer significantly more often when compared to cases with no HGPIN on sextant biopsy. Frequency of concurrent prostate cancer was higher in cases with two or more biopsy specimens containing HGPIN than in cases with only one such biopsy specimen, but case numbers of these categories were too small to render this difference statistically significant. CONCLUSIONS: The presence of HGPIN in sextant biopsies is a significant predictor of concurrent prostate cancer. Multifocality of HGPIN is a useful parameter in assessing the extent of HGPIN in the corresponding prostates. Its value in predicting a significantly increased risk of concurrent prostate cancer needs to be further investigated in larger case studies.

[Highly differentiated hepatocellular tumors. Concepts, criteria, and differential diagnosis]. / Hochdifferenzierte hepatozelluläre Tumoren. Konzepte, Kriterien und Differenzialdiagnose.

Well-differentiated hepatocellular tumors represent a difficult diagnostic problem in hepatopathology with rising clinical impact. The differential diagnosis mainly includes well-differentiated hepatocellular carcinoma (HCC) and its premalignant precursor lesion, the dysplastic nodule (DN), in addition to multiacinar regenerative nodule as well as hepatocellular adenoma (LCA) and focal nodular hyperplasia (FNH). Optimized diagnosis of these lesions is based on exact histomorphological analysis, a close interdisciplinary cooperation as well as good clinical and anamnestic information. Histopathological differential diagnosis requires the search for specific characteristics and detailed analyses of the subtle cytological differences, the histoarchitecture, and also the surrounding nontumorous liver tissue. Special techniques may be helpful in selected cases but currently are of limited importance.

7alpha-Hydroperoxycholesterol causes CNS neuronal cell death.

Brain cholesterol, which is synthesized in the central nervous system and also partly taken up from lipoproteins via the blood-brain barrier, is a major component of neuronal membranes. Oxidation of cholesterol leads to the formation of oxysterols, which have been shown to act cytotoxic. The influence of 7alpha-hydroperoxycholesterol, was investigated using the human neuroblastoma cell line SH-SY5Y. 7alpha-Hydroperoxycholesterol caused neuronal cell death; this neurotoxic effect was dose-dependent, within 48 h 10 microM led to 50%, 50 microM to 92% loss of cell viability, which was detected by cell morphology and Trypan blue exclusion. DNA-fragmentation or caspase-3 activity were not detectable, LDH release occurred rapidly and reactive oxygen species (ROS) were generated. Therefore we infer that 7alpha-hydroperoxycholesterol, apart from its role in atherosclerosis, leads to necrosis of neuronal cells.

LeDantec virus: identification as a rhabdovirus associated with human infection and formation of a new serogroup.

LeDantec virus, originally recovered in 1965 from a patient with a febrile illness in Senegal, was observed by thin section electron microscopy to be bullet-shaped, representative of members of the rhabdovirus group, with mean dimensions of 164 X 78 nm. Particles were observed budding from the plasma membrane and moderate numbers accumulated in the intercellular spaces. In three mammalian cell lines, LeDantec virus was rapidly cytopathic and replicated to moderately high titres. In complement fixation tests with other known rhabdoviruses, LeDantec was found to be related to Keuraliba virus, a previously ungrouped agent isolated from rodents in Senegal in 1968. We propose the formation of a new LeDantec serogroup comprising these two viruses.

Yellow fever monoclonal antibodies: type-specific and cross-reactive determinants identified by immunofluorescence.

Monoclonal antibodies directed against the envelope glycoprotein and the NV3 non-structural viral protein of yellow fever (YF) were tested by the indirect fluorescent antibody technique against a variety of YF virus strains and heterologous flaviviruses. Monoclonal antibodies directed against the envelope glycoprotein exhibited YF strain-specificity, YF type-specificity, broad group cross-reactivity, or limited subgroup reactivity (YF + Banzi or YF + Koutango + Zika + Usutu + Uganda S). Monoclonal antibodies directed against NV3 reacted either with YF + Koutango or with YF + Banzi. These findings generally correlated with the results of biological tests reported previously. Monoclonal antibodies that were type-specific to YF will be useful for the rapid specific identification of YF virus isolates and are available from the Centers for Disease Control on request.