Quantitation of mitomycin C in human ocular tissues by high-performance liquid chromatography-photo-diode array detection

A chromatographic method, which can quantitate mitomycin C (MMC) along with two antiglaucoma drugs, is described. The separation of MMC, alphagan and timolol was performed on a reversed-phase C18 column with water-methanol-trifluoroacetic acid (65:35:0.01, v/v) as the mobile phase. By monitoring at 360, 248 and 296 nm, the lower limits of detection for MMC, alphagan and timolol are, respectively, 1.0, 2.0 and 5.0 ng (injection amount) at three-time S/N ratio. The dynamic ranges of quantitation for the three drugs are, respectively, 1.0 ng-10.0 microg, 2.0 ng-10.0 microg and 5.0 ng-10.0 microg with linearity being larger than 0.9960. This method was applied to the determination of MMC levels in Tenon's and trabeculum tissues of 10 glaucoma patients. MMC levels in these tissues, which were obtained from glaucoma filtering surgery, were determined following a multiple extraction with methanol. The recovery of MMC for a two-batch extraction was better than 91.2%. The reproducibility of measurement for the MMC levels in these tissues is 2.5-6.0% RSD for triplicate injections. The intra-day variation of retention times for the MMC peaks was less than 1.6% RSD (n=3). The inter-day variation of retention times for the MMC peaks was less than 4.8% RSD (n=3). MMC was detectable in three trabeculum tissues out of 10 cases (ranging from 0.8 to 25.5 ng/mg specimen), while MMC was detected in nine Tenon's tissues out of 10 cases (ranging from 0.3 to 21.1 ng/mg specimen). The results obtained show that the method is sensitive and selective for the quantitation of MMC.     

Thinning of fetal pulmonary arterial wall and postnatal remodelling: Ultrastructural studies on the respiratory unit arteries of the pig

Summary Adaptation to extra-uterine life and postnatal remodelling of intra-acinar arteries was followed in 34 Large White pigs, from birth to adult life, applying morphometry to light and electronmicroscopic studies. After birth, percentage wall thickness decreased rapidly due to a reduction in overlap of adjacent smooth muscle cells and an increase in smooth muscle cell surface area/volume ratio, (p<0.01 at 12 h), without a reduction in the volume density of smooth muscle cells. Smooth muscle cells appeared immature at birth and synthetic rather than contractile organelles predominated. Between 3 weeks and 6 months myofilament volume density doubled (p< 0.0001). At all ages, pericytes, intermediate and smooth muscle cells showed similar volume densities of contractile and synthetic organelles. Thus, the high fetal pulmonary vascular resistance appeared to be due to the shape and arrangement of smooth muscle and other contractile cells within the vessel wall, rather than an excessive contractility of these cells. After birth rapid remodelling of arterial wall structure achieved a reduction in wall thickness by 30 min, continuing during the first week of life. After 3 weeks, remodelling involved an increase in wall thickness, connective tissue deposition with more collagen than elastin (p<0.0001), and smooth muscle cell differentiation.     

HER2 protein expression and gene amplification in androgen-independent prostate cancer

The role of the HER2 receptor remains uncertain in the pathogenesis and progression of human prostate cancer. Previous studies have reported widely divergent rates for HER2 expression in primary prostate tumors, probably owing to significant methodologic differences in the studies. Few data exist about the frequency of HER2 protein overexpression and gene amplification in androgen-independent prostate cancer (AIPC), although recent xenograft models suggest HER2 expression may be up-regulated in the transition from androgen-dependent to androgen-independent disease. We studied the role of HER2 protein in AIPC by immunohistochemical and fluorescence in situ hybridization (FISH) analyses on AIPC specimens using well-characterized and validated reagents. Fourteen (36%) of 39 specimens expressed HER2; however, only 2 (5%) had moderate (2+) expression, and 2 (5%) had high-level (3+) expression. Two (6%) of 36 specimens had gene amplification by FISH. These data suggest that HER2 protein overexpression and gene amplification are relatively uncommon in AIPC.     

Determinants of cockroach and mouse exposure and associations with asthma in families and elderly individuals living in New York City public housing.

BACKGROUND: Asthma prevalence is high in the inner city, and morbidity has been associated with cockroach and mouse allergens. OBJECTIVE: To characterize the relationships among pests, allergens, pesticides, and asthma in New York City public housing. METHODS: In 324 apartments, dust samples collected from beds and kitchens were analyzed for cockroach (Bla g 2) and mouse (mouse urinary protein [MUP]) allergens, pest populations were monitored, and residents were interviewed about home characteristics and asthma symptoms. RESULTS: Cockroaches were found in 77% of the apartments, and evidence of mice was found in 13%. Allergens and pesticide use were associated with pest infestation, and 15% of residents reported using illegal pesticides. The percentage of apartments with high allergen levels varied significantly by building (Bla g 2: P = .002; MUP: P = .03), as did the percentage of apartments with cockroaches (P = .002) and daily mouse sightings (P = .02). Thirty-seven percent of the apartments had at least 1 resident with physician-diagnosed asthma. In family buildings, apartments with high Bla g 2 levels had 1.7 times greater odds of having an asthmatic resident (95% confidence interval, 1.2-2.3). In senior citizen buildings, apartments with high MUP levels had 6.6 times greater odds of having an asthmatic resident (95% confidence interval, 1.4-31.7), controlling for smoking and other potential confounders. CONCLUSIONS: Previous studies have identified home characteristics associated with the presence of cockroaches and mice, but the present findings suggest that building-level characteristics can affect high pest exposure. Furthermore, the high asthma prevalence in residents and the use of illegal pesticides highlight the need for safe and effective building-wide pest control strategies.     

Hoechst staining and exposure to UV laser during flow cytometric sorting does not affect the frequency of detected endogenous DNA nicks in abnormal and normal human spermatozoa

Controlling the sex of offspring by the separation of X and Y chromosome-bearing spermatozoa using flow cytometry has been reported as a clinical technique aiding prevention of X-linked diseases. Although this technique has resulted in several hundred normal births in animals and at least one human birth, there is still concern over its genetic safety due to the involvement of two potentially mutagenic agents: UV light and the fluorochrome dye, Hoechst 33342 (H33342). Human spermatozoa, particularly those considered abnormal, may be more likely to suffer DNA damage following exposure to mutagenic agents, compared with other mammalian species. The stability of normal fresh and decondensed human spermatozoa were examined after exposure to a range of levels of UV and H33342 staining, using an assay that detects endogenous nicks in the DNA of spermatozoa. The stability of abnormal and normal, fresh and frozen-thawed human spermatozoa was examined following UV laser, H33342 staining and flow cytometry treatments utilizing the same assay. There was an increase in the presence of endogenous nicks when spermatozoa were decondensed compared with fresh spermatozoa. There was no increase in the incidence of nicks in any group of spermatozoa after UV and fluorochrome exposure compared with controls without exposure.      

Modulation of disease severity of dystrophic epidermolysis bullosa by a splice site mutation in combination with a missense mutation in the COL7A1 gene

Dystrophic epidermolysis bullosa (EBD) is a clinically heterogeneous skin disorder, characterized by abnormal anchoring fibrils (AF) and loss of dermal-epidermal adherence. EBD has been linked to the COL7A1 gene at chromosome 3p21 which encodes collagen VII, the major component of the AF. Here we investigated two unrelated EBD families with different clinical phenotypes and novel combinations of recessive and dominant COL7A1 mutations. Both families shared the same recessive heterozygous 14 bp deletion at the exon-intron 115 boundary of the COL7A1 gene. The deletion caused in-frame skipping of exon 115 and the elimination of 29 amino acid residues from the pro-alpha1(VII) polypeptide chain. As a result, procollagen VII was not converted to collagen VII and the C-terminal NC-2 propeptide which is normally removed from the procollagen VII prior to formation of the anchoring fibrils was retained in the skin. All affected individuals also carried missense mutations in exon 73 of COL7A1 which lead to different glycine- to-arginine substitutions in the triple-helical domain of collagen VII. Combination of the deletion mutation with a G2009R substitution resulted in a mild phenotype. In contrast, combination of the deletion with a G2043R substitution led to a severe phenotype. The G2043R substitution was a de novo mutation which alone caused a mild phenotype. Thus, different combinations of dominant and recessive COL7A1 mutations can modulate disease activity of EBD and alter the clinical presentation of the patients.      

Dustborne and airborne fungal propagules represent a different spectrum of fungi with differing relations to home characteristics

BACKGROUND: Exposure to fungi is often assessed by culturing floor dust or air samples. Our objective was to evaluate the relationships between dustborne and airborne fungi and to identify factors that modify these relationships. METHODS: From November 1994 to September 1996 sequential duplicate 45-l air samples were collected in bedrooms of 496 homes in the Boston area, using a Burkard culture plate sampler. After air sampling, bedroom floors were sampled with a vacuum cleaner that was modified to collect dust in a cellulose extraction thimble. Dust was sieved, and the fine dust was dilution-plated onto DG-18 media. RESULTS: Concentrations of total culturable fungi per gram of bedroom-floor dust were correlated weakly, but significantly, with those of indoor air (r = 0.13, P < 0.05). Concentrations of some individual taxa in the dust and indoor air were also weakly associated. Adjusting for the concentrations of fungi in outdoor air, dustborne fungal concentrations were positively associated with those in indoor air for the taxa Cladosporium and Penicillium, but not for total fungi. The indoor air fungal levels were often predicted by different covariates to those predicting fungal levels in dust. The type of housing (house or apartment) and the presence of carpeting were often predictive factors for dust fungi. In contrast, outdoor fungal levels were often predictive of the indoor air fungal levels. CONCLUSIONS: Because our data do not indicate a strong overall relationship between culturable fungi in dust and indoor air, the results from these two methods (dust and air sampling) likely represent different types of potential fungal exposures to residents. It may be essential to collect both air and dust samples, as well as information on housing characteristics, as indicators for fungal exposure.     

Ultrastructural studies of interactions of B16 melanoma cells and normal mouse skin fibroblasts in the three-dimensional collagen gels in vitro

In the in vivo system, cancer metastasis is a complex multi-step process. We have utilized an in vitro three-dimensional system to study the initial stages of tumour cell invasion. In this communication, the sequence of events in interactions between B16 melanoma cells and normal mouse skin fibroblasts are described. It is proposed that tumour cells produce a "retractive factor" which induces the underlying fibroblasts to retract so as to facilitate invasion and metastasis.     

Paradigm shift in gastrointestinal surgery − combating sarcopenia with prehabilitation: Multimodal review of clinical and scientific data

A growing body of evidence has demonstrated the prognostic significance of sarcopenia in surgical patients as an independent predictor of postoperative complications and outcomes. These included an increased risk of total complications, major complications, re-admissions, infections, severe infections, 30 d mortality, longer hospital stay and increased hospitalization expenditures. A program to enhance recovery after surgery was meant to address these complications; however, compliance to the program since its introduction has been less than ideal. Over the last decade, the concept of prehabilitation, or “pre-surgery rehabilitation”, has been discussed. The presurgical period represents a window of opportunity to boost and optimize the health of an individual, providing a compensatory “buffer” for the imminent reduction in physiological reserve post-surgery. Initial results have been promising. We review the literature to critically review the utility of prehabilitation, not just in the clinical realm, but also in the scientific realm, with a resource management point-of-view.