Quantitative evaluation of the enhanced green fluorescent protein displayed on the cell surface of Saccharomyces cerevisiae by fluorometric and confocal laser scanning microscopic analyses

The number of foreign protein molecules expressed on the cell surface of the budding yeast Saccharomyces cerevisiae by cell surface engineering was quantitatively evaluated using enhanced green fluorescent protein (EGFP). The emission from EGFP on the cell surface was affected by changes in pH. The amount of EGFP on the cell surface, displayed as alpha-agglutinin-fusion protein under control of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoter, was determined at the optimum pH of 7.0. The fluorometric analysis and the image analysis by confocal laser scanning microscopy (CLSM) showed a similar number of molecules displayed on the cell surface, demonstrating that 10(4)-10(5) molecules of alpha-agglutinin-fused molecules per cell were expressed. Furthermore, the amount of fluorescent protein expressed on cells harboring a multicopy plasmid was three to four times higher than that on cells harboring the gene integrated into the genome.

Cell surface-engineered yeast displaying a histidine oligopeptide (hexa-His) has enhanced adsorption of and tolerance to heavy metal ions

A histidine oligopeptide (hexa-His) with the ability to chelate divalent heavy metal ions was displayed on the yeast cell surface for the purpose of enhanced adsorption of heavy metal ions. We genetically fused a hexa-His-encoding gene with the gene encoding the C-terminal half of alpha-agglutinin that includes a glycosylphosphatidylinositol anchor attachment signal sequence and attached the hexa-His peptide on the cell wall of Saccharomyces cerevisiae. This surface-engineered yeast adsorbed three to eight times more copper ions than the parent strain and was more resistant to copper (4 mM) than the parent (below 1 mM at pH 7.8). It was possible to recover about a half of the copper ions adsorbed by whole cells with EDTA treatment without disintegrating the cells. Thus, we succeeded in constructing a novel yeast cell with both tolerance to toxic contaminants and enhanced adsorption of metal ions onto the cell surface.

Development of novel whole-cell immunoadsorbents by yeast surface display of the IgG-binding domain

The ZZ domain derived from Staphylococcus aureus, which binds to the Fc part of immunoglobulin G (IgG), was displayed on the cell surfaces of yeast Saccharomyces cerevisiae by cell-surface engineering using the C-terminal half of alpha-agglutinin under control of the 5'-upstream region of the isocitrate lyase gene from Candida tropicalis (UPR-ICL). Display of ZZ on the cell surface was confirmed by immunofluorescence microscopy. Enzyme-linked immunosorbent assay (ELISA) and sandwich ELISA using the S. cerevisiae cells displaying ZZ detected IgG and antigen (human serum albumin) down to a concentration of 1-10 ng/ml in both cases. The detection range covered by these assay systems was wide and could be varied by adjusting the amount of cells and reaction times with horseradish peroxidase (HRP) substrate. Moreover, yeast cells displaying ZZ were successfully used for repeated affinity purification of IgG from serum. These results indicate that S. cerevisiae displaying ZZ may constitute novel and genetically renewable whole-cell immunoadsorbents widely applicable to immunoassays and affinity purification.

Cell surface-engineered yeast with ability to bind, and self-aggregate in response to, copper ion

In order to construct a cell surface-engineered yeast Saccharomyces cerevisiae that facilitates adsorption and recovery of heavy metal ions, we endowed it with the ability to self-aggregate in response to binding and accumulation of copper ion. A fusion gene for the expression of GTS1, which encodes a putative zinc-finger transcription factor related to occurrence of cell-aggregation, was constructed under the control of the copper ion-inducible CUP1 promoter from the yeast metallothionein gene. The multicopy plasmid carrying the fusion gene was introduced into a cell surface-engineered yeast displaying histidine hexa-peptide, which can chelate copper ion. This transformant strain aggregated in medium only in the presence of copper ion, with aggregation induced by as little as 1 mM copper ion. The copper ion-induced aggregation did not interfere with the copper ion-adsorbing function of the cell surface-engineered yeast, indicating that this transformant strain has the twin features of enhanced cell surface adsorption of copper ion and self-aggregation in response to environmental copper ion.

Creation of cell surface-engineered yeast that display different fluorescent proteins in response to the glucose concentration

We have successfully created a novel yeast strain able to monitor changes in environmental conditions by displaying either green fluorescent protein (GFP) from Aequorea victoria or blue fluorescent protein (BFP), a variant of GFP, on its cell surface as a visible reporter. For the display of these fluorescent proteins on the cell surface of Saccharomyces cerevisiase, our cell-surface-engineering system was utilized. The GAPDH promoter, which is active in the presence of glucose, and the UPR-ICL promoter from Candida tropicalis, which starts to function in the presence of a reduced level of glucose, were employed simultaneously to express the GFP-encoding gene and the BFP-encoding gene, respectively. This cell-surface-engineered yeast strain emitted green fluorescence from the cell surface when sufficient glucose was present in the medium, and blue fluorescence from the same cell surface when the glucose in the medium was consumed. The fluorescent proteins displayed on the cell surface using the different promoters enabled us to monitor the concentrations of intra- and/or extracellular glucose that regulated activation or inactivation of the promoters. This novel yeast strain could facilitate the computerized control of various bioprocesses measuring emitted fluorescence.

The Japanese integrated staging score using liver damage grade for hepatocellular carcinoma in patients after hepatectomy

AIMS

The new Japanese staging system for hepatocellular carcinoma (HCC), the Japan integrated staging (JIS) score, accounts for both Child-Pugh classification and Japan tumour node metastasis (TNM) staging. However, in HCC patients who undergo hepatectomy, liver function is relatively good and a better prognostic classification of hepatic function is necessary.

METHODS

The present study was designed to analyse the modified JIS score using liver damage grade by the Liver Cancer Study Group of Japan instead of the Child-Pugh classification (using the category indocyanine green retention rate at 15 min [ICG(R15)] instead of encephalopathy), and to compare the Japan TNM stage in 101 patients who underwent resection of HCC.

RESULTS

The liver damage grade showed significantly better discrimination of disease-free and overall survival than did the Child-Pugh classification. The modified JIS score system showed significant differences of disease-free and overall survivals in each score and this system was superior for discriminating survivals compared with the TNM staging.

CONCLUSIONS

The combined staging system of hepatic function, particularly ICG(R15), and tumour stage provides a better prediction of prognosis. The JIS score using the liver damage grade was a useful predictor of prognosis of HCC patients who underwent hepatic resection.

Construction of an engineered yeast with glucose-inducible emission of green fluorescence from the cell surface

An engineered yeast with emission of fluorescence from the cell surface was constructed. Cell surface engineering was applied to display a visible reporter molecule, green fluorescent protein (GFP). A glucose-inducible promoter GAPDH as a model promoter was selected to control the expression of the reporter gene in response to environmental changes. The GFP gene was fused with the gene encoding the C-terminal half of alpha-agglutinin of Saccharomyces cerevisiae having a glycosylphosphatidylinositol anchor attachment signal sequence. A secretion signal sequence of the fungal glucoamylase precursor protein was connected to the N-terminal of GFP. This designed gene was integrated into the TRP1 locus of the chromosome of S. cerevisiae with homologous recombination. Fluorescence microscopy demonstrated that the transformant cells emitted green fluorescence derived from functionally expressed GFP involved in the fusion molecule. The surface display of GFP was further verified by immunofluorescence labeling with a polyclonal antibody (raised in rabbits) against GFP as the first antibody and Rhodamine Red-X-conjugated goat anti-rabbit IgG as the second antibody which cannot penetrate into the cell membrane. The display of GFP on the cell surface was confirmed using a confocal laser scanning microscope and by measuring fluorescence in each cell fraction obtained after the subcellular fractionation. As GFP was proved to be displayed as an active form on the cell surface, selection of promoters will endow yeast cells with abilities to respond to changes in environmental conditions, including nutrient concentrations in the media, through the emission of fluorescence.

Measurement of serum hyaluronic acid level during the perioperative period of liver resection for evaluation of functional liver reserve

BACKGROUND AND AIM

The serum hyaluronic acid (HA) concentrations reflect the degree of hepatic fibrosis and sinusoidal endothelial cell damage. The HA concentrations were examined to evaluate liver damage during the perioperative period of hepatectomy.

METHODS

The HA level of serum samples from 79 patients who underwent a hepatectomy was measured, and the results were compared to conventional liver function tests, the degree of fibrosis, liver regeneration and complications.

RESULTS

Hyaluronic acid concentrations correlated with the severe fibrosis or histological activity index, and also correlated with liver function tests including transaminase level, platelet counts, prothrombin time activity, indocyanine green retention rate at 15 min (ICG R15), liver activity at 15 min by technetium-99m galactosyl human serum albumin scintigraphy (LHL 15), and portal pressure. The HA level postoperatively correlated with liver function, especially with total bilirubin. Hyaluronic acid levels at day 28 postoperatively correlated with ICG R15 and LHL 15. The hyaluronic acid level before surgery and at day 28 postoperatively correlated with the regeneration of remnant liver in major hepatectomy. The HA levels were significantly higher in patients with hepatic failure or prolonged ascites.

CONCLUSION

Our results indicate that the measurement of the HA level is useful for monitoring liver damage or predicting complications associated with liver surgery.

Clinical evaluation of magnetic resonance imaging flowmetry of portal and hepatic veins in patients following hepatectomy

BACKGROUND

Hepatic blood flow was associated with degree of hepatic damage. Measurements of blood flow using ultrasonography (US) may vary due to any observer's and patient's conditions. The utility of magnetic resonance imaging (MRI) flowmetry in portal and hepatic veins was assessed.

PATIENTS AND METHODS

Using the phase-contrast method, the mean flow velocity of portal (PVF) and hepatic vein (HVF) were determined by MRI and US in 75 consecutive patients with liver diseases, including 58 patients undergoing hepatectomy. The correlations between these parameters and clinicopathological findings were examined.

RESULTS

PVF and HVF measured by MRI flowmetry were 12.8+/-4.5 and 14.7+/-5.3 cm/s, respectively. There was no significant correlation of both flows between MRI and US. PVF correlated significantly with portal pressure (r = -0.722; P < 0.05). There was a negative correlation between HVF and histological activity index score (r = -0.366; P < 0.05). PVF and HVF were lower in patients with cirrhosis and higher staging score (2-4) and PVF was lower in patients with higher grading score (2-3; P < 0.05). PVF and HVF were not significantly associated with postoperative complications.

CONCLUSIONS

Our results suggest that MRI flowmetry is a potentially useful tool for measurement of hepatic blood flow and recommend its use for estimation of liver cirrhosis-associated impairment.

Modified CLIP using PIVKA-II for evaluating prognosis after hepatectomy for hepatocellular carcinoma

AIMS

The new staging system proposed by the Cancer of the Liver Italian Program (CLIP) for hepatocellular carcinoma (HCC) accounts for both liver dysfunction and tumour characteristics. The present study was designed to analyze UICC TNM stage, CLIP and modified CLIP in 91 patients who underwent hepatic resection for HCC.

METHODS

In the modified CLIP, scoring of AFP was replaced by that of protein induced by vitamin K absence or antagonist II (PIVKA-II; predictive value, > or = 400 mAU/ml).

RESULTS

After hepatic resection, 54 patients developed recurrent tumours. High PIVKA-II was a significant determinant of recurrence (p<0.05). However, a high score of the modified CLIP as well as those other staging systems did not correlate with tumour-recurrence rate. Univariate analysis showed that high TNM score, CLIP score and our modified CLIP score were significant predictors of poor prognosis. Multivariate Cox's analysis revealed that high PIVKA-II and high modified CLIP score were associated with higher risk for disease-free and overall survival as well as high TNM stage.

CONCLUSIONS

Compared with the original CLIP, our modified CLIP was a better predictor of prognosis of HCC patients who underwent hepatic resection.

Light and electron microscopic study on the endocrine cells of the pancreas in a marine teleost, Fugu rubripes rubripes

The pancreatic endocrine tissue of Fugu rubripes rubripes consists of numerous round principal islets (Brockmann bodies) of various sizes scattered around the gall-bladder. The endocrine cells are divided into A-, B-, D-, and Ff-cells. Each cell type was identified by comparing thick and thin sections in both light and electron microscopy. Aldehyde-fuchsin positive B-cells contain numerous round secretory granules (average diameter 300 nm) each of which has a round compact core of moderate density; a narrow space exists between this core and the limiting membrane. Grimelius' silver positive A cells contain round secretory granules (average diameter 360 nm) with a hexagonal or tetragonal crystalline core (average diameter 170 nm) of high density; the silver grains perferentially appear in the space between the limiting membrane and the core. The crystalline core of each alpha-granule often contains an appendix like structure of variable shape. D cells blackened by the silver impregnation method of Hellman and Hellerström (1960) have round secretory granules (average diameter 320 nm) filled with a flocculent material of low density. The fourth cell type (Ff-cell) has a clear cytoplasm after differential staining for light microscopy. By electron microscopy, this cell has elongated fusiform secretory granules (520 nm average length x 230 nm average width) filled with numerous filaments arranged in parallel with the longitudinal axis. Figures suggesting granule formation in the sacs of the Golgi apparatus were obtained in all of islet cell types. Equivalents of emiocytotic release of secretory granules were encountered in the A and Ff cells.

A fine structure study of the non-ciliated cells in the mouse tracheal epithelium with special reference to the relation of "brush cells" and "endocrine cells"

The non-ciliated epithelial cells in the air way of mice were examined by electron microscopy. They are flask-like or pyramidal cells dispersed singly or occasionally in pairs. The apical portion of the cells reaches the air way lumen with microvillous projections. Their cytoplasm always contains abundant and variable numbers of small granules (60-170 nm in diameter). Close appositions between non-ciliated cells and nerve fibers are frequently observed at their lateral or basal surfaces. Fine structures of the non-ciliated cells are similar to those previously reported in the cells under different designations such as brush cells, basal-granulated cells, cells of neuroepithelial bodies and endocrine cells. The present study proposes that these names express different features of the same cell group collectively called "non-ciliated cells" in this paper. Furthermore images indicating exocytotic granule release are obtained in this study, indicating an endocrine function of these cells.

Polymerization Behavior and Mechanical Properties of High-Viscosity Bulk Fill and Low Shrinkage Resin Composites

The present study determined the mechanical properties and volumetric polymerization shrinkage of different categories of resin composite. Three high viscosity bulk fill resin composites were tested: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent), Filtek Bulk Fill posterior restorative (FB, 3M ESPE), and Sonic Fill (SF, Kerr Corp). Two low-shrinkage resin composites, Kalore (KL, GC Corp) and Filtek LS Posterior (LS, 3M ESPE), were used. Three conventional resin composites, Herculite Ultra (HU, Kerr Corp), Estelite ∑ Quick (EQ, Tokuyama Dental), and Filtek Supreme Ultra (SU, 3M ESPE), were used as comparison materials. Following ISO Specification 4049, six specimens for each resin composite were used to determine flexural strength, elastic modulus, and resilience. Volumetric polymerization shrinkage was determined using a water-filled dilatometer. Data were evaluated using analysis of variance followed by Tukey's honestly significant difference test (α=0.05). The flexural strength of the resin composites ranged from 115.4 to 148.1 MPa, the elastic modulus ranged from 5.6 to 13.4 GPa, and the resilience ranged from 0.70 to 1.0 MJ/m3. There were significant differences in flexural properties between the materials but no clear outliers. Volumetric changes as a function of time over a duration of 180 seconds depended on the type of resin composite. However, for all the resin composites, apart from LS, volumetric shrinkage began soon after the start of light irradiation, and a rapid decrease in volume during light irradiation followed by a slower decrease was observed. The low shrinkage resin composites KL and LS showed significantly lower volumetric shrinkage than the other tested materials at the measuring point of 180 seconds. In contrast, the three bulk fill resin composites showed higher volumetric change than the other resin composites. The findings from this study provide clinicians with valuable information regarding the mechanical properties and polymerization kinetics of these categories of current resin composite.

Influence of Different Curing Modes on Polymerization Behavior and Mechanical Properties of Dual-Cured Provisional Resins

This study determined the influence of curing mode on polymerization behavior and mechanical properties of dual-cured provisional resins. Three dual-cured bisacryl-based provisional resins were used: Tempsmart (TS; GC Corp), Luxatemp Automix Solar (LX; DMG Chemisch Pharmazeutishe Fabrik GmbH), and Integrity Multi·Cure (IG; Dentsply Caulk). A self-cured bisacryl-based provisional resin, Protemp Plus (PP; 3M ESPE) and a conventional poly(methyl methacrylate) (PMMA) provisional resin, Unifast III (UF; GC Corp) were used as controls. The inorganic filler content and coefficients of linear thermal expansion of the test materials were measured. Six specimens of each material were used to determine the flexural strength, elastic modulus, and resilience. The changes in ultrasound velocity during polymerization were measured. The average inorganic filler contents of the provisional resins, apart from UF, ranged from 24.4 to 39.3 wt%. The highest inorganic filler content was determined for LX, whereas TS showed the lowest value among the tested materials. The average coefficients of thermal expansion of the tested provisional resins ranged from 77.3 to 107.7 (×10^-6/°C). TS and IG showed significantly lower thermal expansions than the other tested provisional resins. The mean flexural strengths of the provisional resins ranged from 70.4 to 122.6 MPa, the mean elastic moduli ranged from 1.8 to 3.7 GPa, and the mean resilience of the provisional resins ranged from 1.1 to 2.3 MJ/mm³, respectively. Dual-cured provisional resins showed significantly higher flexural strengths than the PMMA resin. However, in all cases, the light-curing mode showed significantly higher flexural strengths than the self-curing mode. In the initial polymerization phase, dual-cured resins in the light-curing mode showed a rapid increase in the speed of sound (V) during light irradiation, followed by a slower increase. Conversely, the dual-cured resins in the self-curing mode showed a slower initial increase, followed by a rapid increase. Although no significant difference in V was observed between 10 and 15 minutes in the light-curing mode of all tested dual-cured resins, a significantly higher V value was obtained at 15 minutes than at 10 minutes in the self-curing modes for LX and IG. Regardless of the curing mode, tested dual-cured provisional resins showed superior mechanical properties than the conventional PMMA provisional resin. However, dual-cured provisional resin flexural properties and polymerization behavior were affected by the curing mode. This study indicated that the light-curing mode might be recommended for all dual-cured provisional resins because of the enhancement of their mechanical properties and reduction of chair time.

Comparative study of survival of patients with hepatocellular carcinoma predicted by different staging systems using multivariate analysis

AIMS

In a previous pilot study, we reported the usefulness of the modified the Cancer of the Liver Italian Program (CLIP) score for patients with hepatocellular carcinoma (HCC). To determine the best staging system for predicting the survival of HCC patients, we conducted a comparative analysis of prognosis using multivariate analysis in 210 Japanese HCC patients who underwent hepatic resection.

METHODS

We compared the survival as predicted by various staging systems, including tumour node metastasis (TNM) stage of the American Joint Commission on Cancer (AJCC) and the Liver Cancer Study Group of Japan, the Japan Integrated Staging (JIS) score (Japanese TNM and Child-Pugh classification), CLIP score and our modified CLIP score using protein induced by vitamin K absence or antagonist II (PIVKA-II).

RESULTS

Univariate analysis showed that discrimination of disease-free survival in the early and advanced stages by the JIS score and modified CLIP score was clearer than by the Japanese or AJCC TNM or the original CLIP score. Discrimination between stages of overall survival by all staging systems was significant. Multivariate analysis showed that the JIS, CLIP and modified CLIP scores were better staging systems for predicting survival than the Japanese and AJCC TNM. The modified CLIP score showed the lowest Akaike information criteria statistical value for disease-free and overall survival, which means the best discrimination ability for patient survival compared with the JIS score and CLIP score.

CONCLUSIONS

A staging system that combines tumour factors, sensitive tumour marker(s) and hepatic function is the best predictor of prognosis of HCC patients.

A transportation network for human ovarian tissue is indispensable to success for fertility preservation

PURPOSE

The purpose of this study was to examine the efficacy of an ovarian tissue transportation network for fertility preservation (FP) for cancer patients in Japan.

METHODS

PubMed was searched for papers on transportation of human ovarian tissue for FP. We analyzed population, area, number of cancer patients for ovarian tissue cryopreservation (OTC), quality control/assessment and safety, cost of a cryopreservation center for the building for 30 years, and medical fees of cancer patients (operation, cryopreservation, and storage of ovarian tissue).

RESULTS

More than twenty babies have been born in Denmark and Germany through a transportation system. Up to 400 new patients a year need OTC. The fees for removal, cryopreservation, and storage for 5 years, and transplantation of ovarian tissue are around €5,000, €4,000, and €5,000, respectively. It costs more than €5 million to establish and maintain one cryopreservation center for 30 years. If we have a few cryopreservation centers in Japan, we can cryopreserve 400 patients' ovarian tissue per year by safer slow freezing and maintain quality control/assessment. We need to lighten the patients' burden for easy to use FP by a government subsidy and medical insurance coverage.

CONCLUSIONS

This model has been termed the Danish model ("the woman stays - the tissue moves"). This is truly patient-centered medicine. We can have maximum effects with the minimum burden. A transportation network like those of Denmark and Germany is the best strategy for FP in Japan. It may be the best system for cancer patients, medical staff, and the Ministry of Health, Labor, and Welfare.

Intelligent yeast strains with the ability to self-monitor the concentrations of intra- and extracellular phosphate or ammonium ion by emission of fluorescence from the cell surface

Saccharomyces cerevisiae strains that respond to environmental changes and transmit the information by emission of fluorescence from the cell surface were constructed. The technique of cell surface engineering enabled the yeast cells to display enhanced cyan blue fluorescent protein (ECFP) or enhanced yellow fluorescent protein (EYFP) on the surface under the control of promoters that sense environmental changes. Two model promoters were examined in this study. For monitoring the intra- and extracellular concentrations of phosphate ion, the PHO5 promoter was chosen to display ECFP. The MEP2 promoter was used to display EYFP to sense the concentrations of ammonium ion. Fluorescence was observed by fluorescence microscopy and immunofluorescence microscopy, and the intensity was measured by a flow cytometer. The relationship between ion concentration inside and outside the cells was evaluated by the change in the rate of fluorescence. This S. cerevisiae system enables environmental changes to be transmitted as intra- and extracellular information using a suitable promoter functioning at real time and in a non-invasive manner.

An arming yeast with the ability to entrap fluorescent 17beta-estradiol on the cell surface

We constructed a novel surface-engineered yeast displaying the ligand-binding domain of the rat estrogen receptor (ERLBD). ERLBD, display of which on the yeast cell surface was confirmed by immunofluorescence, possessed strong binding activity to fluorescent 17beta-estradiol - an analogue of the natural ligand of the estrogen receptor - that was comparable to the activity of the native receptor. Environmental homeostasis has recently been disturbed by endocrine disruptors, which cause confusion in the hormone secretion system. It is therefore very important to identify chemical compounds with hormone-like activity and remove them from the environment. The present results demonstrate that the new arming yeast displaying ERLBD on its cell surface will be capable of screening, entrapping, and removing estradiol-like compounds from the environment.

Controlling evening BP as well as morning BP is important in hypertensive patients with prediabetes/diabetes: the JMS-1 study

BACKGROUND

The significance of home blood pressure (BP) measurement in type 2 diabetes (T2DM) has not been well investigated. We aimed to test the hypotheses that home BP is more closely associated with target-organ damage than clinic BP, and that the presence of prediabetes/T2DM enhances the impact of home BP measurement.

METHODS

We studied 551 hypertensives (99 diabetics and 452 nondiabetics) whose self-measured systolic BP (SBP) was >135 mm Hg while on medication. The subjects were followed for 6 months after allocation to either a control group or an active treatment group. The changes in clinic BP and home BP were analyzed in relation to the changes in the spot urine albumin-creatinine ratio (UAR).

RESULTS

The extent of clinic and home BP reduction was similar between the diabetic and nondiabetic groups. The change in UAR in nondiabetics was significantly associated with the extent of SBP reduction in the clinic (r = 0.19), morning (r = 0.33), and evening (r = 0.22, all P < 0.01). In contrast, in the diabetic group, the change in UAR was significantly associated with the changes in morning SBP (r = 0.23, P = 0.02) and evening SBP (r = 0.39, P < 0.001), but not with clinic BP. The correlation with evening SBP in the diabetic group tended to be stronger than the nondiabetic group.

CONCLUSIONS

In hypertensives with prediabetes/T2DM, changes in home BP were better than changes in clinic BP to predict changes in UAR. In particular, this suggests the hypothesis that aggressive control of evening home BP might be equally or more important to morning BP in hypertensives with prediabetes/T2DM.

High prevalence of asthma in five remote indigenous communities in Australia

Data on the prevalence of asthma in children residing in remote indigenous communities in Australia are sparse, despite the many reports of high prevalence in nonindigenous children of this country. Two previous Australian studies have had poor participation rates, limiting interpretation of their results. A study of children in the Torres Strait and Northern Peninsula Area of Australia was conducted to document the prevalence of asthma symptoms. Five indigenous communities were randomly selected and trained interviewers, who were local indigenous health workers, recruited participants using a house-by-house approach. Information was collected by a structured face-to-face interview based on a standardized questionnaire constructed from the protocol International Study of Asthma and Allergy in Childhood; 1,650 children were included in the study with a 98% response rate. Overall, the prevalence of self-reported ever wheezing was 21%; 12% reported wheezing in the previous year; and 16% reported ever having asthma. There was significant variation in the prevalence of asthma symptoms between communities. It is concluded that there are significant intercommunity variations in the prevalence of asthma symptoms in remote communities and that the prevalence in these communities is as high as in nonindigenous groups.

Further electron-microscope studies on the human hepatic sinusoidal wall with special reference to the fat-storing cell

In biopsy specimens from two normal human livers, fat-storing cells and Kupffer cells were observed by electron microscopy with the following results: 1) In the human Ito cells numerous micropinocytotic caveolae and vesicles occurred either scattered beneath the plasma membrane or fused into short tubules. In the cytoplasm abutting on these structures, minute clusters of glycogen beta-particles were revealed which presumably had been synthesized in the local cytoplasm from carbohydrate (glucose) ingested by pinocytosis. 2) Lipid droplets (vacuoles) were formed within the accumulations of the glycogen beta-particles. These findings support the view that the glycogen synthesized in the Ito cells may represent a transitional compound in the process of lipid synthesis from carbohydrate. 3) Among lipid vacuoles, electron-dense droplets equally large were found, often containing electron-lucent areas in their center. On the surface of these dense droplets, compact clusters of glycogen particles adhered as if they might have permeated into the droplets. These droplets may possibly be immature lipid droplets retaining chemical properties of the glycogen in their superficial part; they remained insoluble during the preparation procedures for ultrathin sections. 4) The occurrence of the worm-like structure has for the first time been revealed in the human Kupffer cells. Besides its short tubular profiles, a more complex structure was demonstrated.