Mesoporous Gold: Substrate-Dependent Growth Dynamics, Strain Accumulation, and Electrocatalytic Activity for Biosensing

Understanding the growth of mesoporous crystalline materials, such as mesoporous metals, on different substrates can provide valuable insights into the crystal growth dynamics and the redox reactions that influence their electrochemical sensing performance. Herein, it is demonstrated how the amorphous nature of the glass substrate can suppress the typical <111> oriented growth in mesoporous Au (mAu) films. The suppressed <111> growth is manifested as an accumulation of strain, leading to the generation of abundant surface defects, which are beneficial for enhancing the electrochemical activity. The fine structuring attained enables dramatically accelerated diffusion and enhances the electrochemical sensing performance for disease-specific biomolecules. As a proof-of-concept, the as-fabricated glass-grown mAu film demonstrates high sensitivity in electrochemical detection of SARS-CoV-2-specific RNA with a limit of detection (LoD) as low as 1 attomolar (aM).

Synthesis of millimeter-scale ZIF-8 single crystals and their reversible crystal structure changes

Among various metal-organic frameworks (MOFs), the zeolitic imidazole framework (ZIF), constructed by the regular arrangement of 2-methylimidazole and metal ions, has garnered significant attention due to its distinctive crystals and pore structures. Variations in the sizes and shapes of ZIF crystals have been reported by changing the synthesis parameters, such as the molar ratios of organic ligands to metal ions, choice of solvents, and temperatures. Nonetheless, the giant ZIF-8 single crystals beyond the typical range have rarely been reported. Herein, we present the synthesis of millimeter-scale single crystal ZIF-8 using the solvothermal method in N,N-diethylformamide. The resulting 1-mm single crystal is carefully characterized through N2 adsorption-desorption isotherms, scanning electron microscopy, and other analytical techniques. Additionally, single-crystal X-ray diffraction is employed to comprehensively investigate the framework's mobility at various temperatures.

Single-crystal structure analysis of non-deuterated triglycine sulfate by neutron diffraction at 20 and 298 K: a new disorder model for the 298 K structure

A precise crystal-structure analysis using a neutron diffractometer with high-power neutron sources at the J-PARC facility has been performed on non-deuterated triglycine sulfate at 20 K and 298 K and a new double-potential-well disorder model for the O—H⋯O hydrogen bond in the 298 K structure is proposed.

Precise single-crystal structure analyses of the title compound, bis­(glycinium) sulfate–glycine (1/1), 2C₂H₆NO₂⁺·SO₄²⁻·C₂H₅NO₂ (or C₆H₁₇N₃O₁₀S), non-deuterated triglycine sulfate (HTGS) at 20 K and 298 K were undertaken using time-of-flight neutron diffraction data. At 20 K for the O—H⋯O hydrogen bond between the glycinium cation and the zwitterionic, unprotonated glycine mol­ecule that is associated with the ferroelectric behaviour of HTGS, O—H = 1.070 (3), H⋯O = 1.408 (3) [δ = 0.338 (4)], O⋯O = 2.4777 (15) Å and O—H⋯O = 179.0 (4)°, which is in good agreement with previous studies. Two reasonable structures for the same three atoms were refined for the 298 K dataset. One is a single-minimum potential-energy model, with O—H = 1.090 (12), H⋯O = 1.361 (12) [δ = 0.271 (17)], O⋯O = 2.450 (7) Å and O—H⋯O = 179.2 (10)°, having the H atom with a large ellipticity along the bond path between the O atoms. The other is a double-minimum potential-energy model having two H atom sites with occupancies of 0.876 (8) and 0.124 (8): for the major occupancy component, O—H = 1.065 (12), H⋯O = 1.387 (12), O⋯O = 2.451 (7) Å and O—H⋯O = 178.2 (11)° and for the minor component, O—H = 1.06 (4), H⋯O = 1.41 (4), O⋯O = 2.451 (7) Å and O—H⋯O = 166 (2)°. These models did not show any significant differences in R factors. In addition, the unit-cell parameters and other structural parameters of HTGS did not show any major differences compared to those of partially deuterated TGS and fully deuterated TGS for both 20 K and 298 K.

A bolus of saline injection leads to increase in coronary flow based on the viscosity reduction effect: the mechanism of saline induced Pd/Pa ratio

Background

In conjunction with fractional flow reserve (FFR), our previous study has shown the accuracy and utility of saline induced Pd/Pa ratio (SPR) for the assessment of myocardial ischemia. However, the potential mechanism how saline injection leads to increase in coronary flow remains speculative.

Purpose

This study aimed to clarify the underlying mechanism of SPR by using swine models.

Methods

The study was conducted in four swine models, and bolus of 25°C saline, 40°C saline, and 25°C dextran was injected at rates of 40mL/5sec through a catheter inserted into the superior mesenteric artery. Its peripheral arterioles were observed and recorded by a digital microscope, and transit time of each fluid and a luminal diameter of arterioles before and after injection were measured.

Results

The result from arterioles diameters of pre- and post-injection (0.049±0.016mm vs. 0.050±0.016mm; P=0.636) indicated that luminal diameters remained unchanged regardless of fluid administration. The transit time of 25°C saline was significantly shorter than 25°C dextran (3.19±0.68sec vs. 6.15±1.19sec; P&lt;0.0001). Although the result showed no significance, the transit time of 40°C saline with lower viscosity was shorten compared to 25°C saline (3.1±0.43sec vs. 3.65±0.46sec; P=0.088).

Conclusions

Compared to 25°C dextran (viscosity of 4.991mPa·s) having the same viscosity as 37°C whole blood, 25°C saline (viscosity of 1.012mPa·s) caused increasing to double the intravascular flow volume without dilating arterioles. The results strongly suggested that the potential mechanism of SPR was viscosity reduction effect. Combined with FFR which is based on vasodilation-mediated hyperemia, these findings may contribute to clarifying the pathophysiology and especially the microcirculation in coronary artery diseases.

Funding Acknowledgement

Type of funding source: None

CMOS-based smart-electrode-type retinal stimulator with bullet-shaped bulk Pt electrodes

A CMOS-based flexible retinal stimulator equipped with bullet-shaped bulk Pt electrodes was fabricated and demonstrated. We designed a new CMOS unit chip with an on-chip stimulator, single- and multi-site stimulation modes, and monitoring functions. We have developed a new structure and packaging process of flexible retinal stimulator with bullet-type bulk Pt electrode. We have confirmed the retinal stimulation functionality in an in vivo stimulation trial on rabbit's retina.

Multi-finger structure and pulsed-powering operation scheme for CMOS LSI-based flexible stimulator for retinal prosthesis

Multi-finger structure was proposed to improve flexibility of the CMOS LSI-based multi-chip retinal stimulator. A dual-finger retinal stimulator was fabricated and its functionality was demonstrated in retinal stimulation experiments on rabbit's retina, We also proposed an idea of pulsed-powering operation scheme for the multi-chip flexible retinal stimulator. We compared the pulsed-powering scheme with conventional one in a simulation, and show that the pulsed-powering can be an alternative operation scheme for the neural stimulator that provides an improved safety to the biological tissue.

In vivo stimulation on rabbit retina using CMOS LSI-based multi-chip flexible stimulator for retinal prosthesis

We have performed in vivo electric stimulation experiments on rabbit retina to demonstrate feasibility of CMOS LSI-based multi-chip flexible neural stimulator for retinal prosthesis. We have developed new packaging structure with an improved flexibility and device control system which totally controls the LSI-based multi-chip stimulator, counter electrode, and stimulation generator. We have implanted the fabricated multi-chip stimulator into sclera pocket for STS (Suprachoroidal Transretinal Stimulation) configuration. We successfully obtained EEP (Electrically Evoked Potential) on visual cortex evoked by the multi-chip stimulator.

Laboratory investigation of microelectronics-based stimulators for large-scale suprachoroidal transretinal stimulation (STS)

This paper describes the technological developments underlying the realization of a reliable and reproducible microchip-based stimulator with a large number of stimulus electrodes. A microchip-based stimulator with over 500 electrodes for suprachoroidal transretinal stimulation (STS) is proposed in this paper, and an example is presented. To enhance reliability and reproducibility for such a large array, we introduce a flip-chip bonding technique and place microchips on the reverse side of a substrate. A square microchip of size 600 microm was fabricated using 0.35 microm standard CMOS process technology. Twelve microchips were flip-chip bonded on a polyimide substrate through Au bumps. To evaluate the feasibility of the proposed device, we successfully fabricated a stimulator with 12 microchips and 118 electrodes made of Pt/Au bumps, and demonstrated their operation in a saline solution for 2 weeks. Also, to evaluate the device operation in vivo, a stimulator with one active IrO(x) electrode was implanted into the scleral pocket of a rabbit and electrical evoked potential (EEP) signals with a threshold of 100 microA were obtained. We also fabricated a simulator with 64 microchips that has 576 electrodes (9 electrodes in a microchip times 64 microchips).

Increased atherosclerosis in hyperlipidemic mice deficient in alpha -tocopherol transfer protein and vitamin E

Although lipid peroxidation in the subendothelial space has been hypothesized to play a central role in atherogenesis, the role of vitamin E in preventing lipid peroxidation and lesion development remains uncertain. Here we show that in atherosclerosis-susceptible apolipoprotein E knockout mice, vitamin E deficiency caused by disruption of the alpha-tocopherol transfer protein gene (Ttpa) increased the severity of atherosclerotic lesions in the proximal aorta. The increase was associated with increased levels of isoprostanes, a marker of lipid peroxidation, in aortic tissue. These results show that vitamin E deficiency promotes atherosclerosis in a susceptible setting and support the hypothesis that lipid peroxidation contributes to lesion development. Ttpa(-/-) mice are a genetic model of vitamin E deficiency and should be valuable for studying other diseases in which oxidative stress is thought to play a role.

Enhancing effect of dietary oil emulsions on immune responses to protein antigens fed to mice

Repeated intragastric administration of beta-lactoglobulin (beta-Lg) with emulsified soybean oil elicited an antigen-specific, systemic humoral immune response in different strains of mice. The antibody response was enhanced as the dose of oil was increased and the particle size of emulsions was decreased. Feeding of aqueous beta-Lg could induce the antibody response only when emulsified oil was fed almost simultaneously. However, the emulsion-driven humoral immune response was not observed when mice were treated with anti-CD40 ligand antibody or in athymic mice. It is likely that the intestinal coexistence of emulsified oil with dietary antigens modulates the immune system to crucially support B cell response. A practical application of the present results to the prevention of cow's milk protein sensitization in infants is proposed.

[Characteristics of incidentally detected renal cell carcinoma by ultrasonography at health check-up]

BACKGROUND

The prognosis of patients with incidentally detected renal cell carcinoma is better than that of patients with symptomatic renal cell carcinoma. These incidentalomas include those discovered by ultrasonography at health check-up and those found during examinations for unrelated disease. In this study, we investigated the prognosis of the patients of the health check-up group and the unrelated disease group.

METHODS

From April 1987 to March 1997, 263 patients with renal cell carcinoma were treated in our department including 166 incidentalomas (63.1%). The occasion of incidental detection was divided into 2 groups; 90 cases as health check-up group and 76 cases as unrelated disease group.

RESULTS

The mean age was 52.9 +/- 9.7 years for health check-up group and 65.1 +/- 11.4 years for unrelated disease group (p < 0.01). The mean evaluated tumor size was 3.6 +/- 1.6 cm for health check-up group and 4.4 +/- 2.6 cm for unrelated disease group (p < 0.05). The survival rates were significantly different in the two groups (p < 0.01); the 5- and 10-year survival rate for health check-up group was 91.5% and 55.9%, respectively and for unrelated disease group 79.4% and 66.1%, respectively.

CONCLUSION

These results suggested that examination by ultrasonography at health check-up lead to detection of smaller renal cell carcinoma and improve the prognosis further.

Alpha-tocopherol protects against monocyte Mac-1 (CD11b/CD18) expression and Mac-1-dependent adhesion to endothelial cells induced by oxidized low-density lipoprotein

Alpha-tocopherol supplementation is reported to protect against cardiovascular disease and to influence cells involved in atherogenesis, such as monocytes. Interactions between monocytes and vascular endothelial cells occur early in atherogenesis, and adhesion is mediated by integrins. We evaluated the effects of alpha-tocopherol on expression of Mac-1 (CD11b/CD18) by monocytes after stimulation with oxidized low-density lipoprotein (LDL), which is implicated as a potent chemotactic agent in atherogenesis. Incubation of whole blood with oxidized LDL (100 microg/ml) increased Mac-1 expression on monocytes, and preincubation with alpha-tocopherol reduced this upregulation in a concentration dependent manner. In another experiment, whole blood was obtained from healthy adult volunteers after 10 days of alpha-tocopherol administration (600 mg/day) and was incubated with oxidized LDL (100 microg/ml). There was a decrease in the upregulation of Mac-1 compared with that measured before administration. Adherence of oxidized LDL-stimulated monocytes to human umbilical vein endothelial cells was reduced by pretreatment with alpha-tocopherol, and was also inhibited by an anti-CD18 monoclonal antibody. Experiments with protein kinase C inhibitors suggested that reduction of Mac-1 upregulation by alpha-tocopherol was secondary to a decrease of protein kinase C activity. In conclusion, alpha-tocopherol suppressed the upregulation of Mac-1 expression on monocytes by oxidized LDL.

Inhibitory effects of vitamin E on endothelial-dependent adhesive interactions with leukocytes induced by oxidized low density lipoprotein

Leukocyte-endothelial cell interactions, which are mediated by various adhesion molecules, are a crucial event in inflammatory reactions including atherosclerosis. Alpha-tocopherol (alpha-Toc) has been used for protection and therapy of vascular diseases because of its antioxidant activity. The objective of the present study was to determine effect of alpha-Toc on endothelial-dependent adhesive interactions with leukocytes elicited by oxidized low density lipoprotein (oxLDL). Incubation of HUVEC with oxLDL (100 microg/mL) increased expression of proteins and messenger RNA of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on enzyme immunoassay and northern blotting assay; pretreatment with alpha-Toc reduced in a dose dependent manner. Adherence of polymorphonuclear leukocytes (PMN) or mononuclear leukocytes (MNC) to oxLDL-activated HUVEC was much increased compared with that to unstimulated HUVEC. Treatment of HUVEC with alpha-Toc, monoclonal antibody to ICAM-1 or VCAM-1 inhibited adherence of PMN or MNC in a dose dependent manner. These results suggest that alpha-Toc works as anti-atherogenic agent through inhibiting endothelial-dependent adhesive interactions with leukocytes induced by oxLDL.

Apolipoprotein B-related gene expression and ultrastructural characteristics of lipoprotein secretion in mouse yolk sac during embryonic development

In mice, the yolk sac appears to play a crucial role in nourishing the developing embryo, especially during embryonic days (E) 7;-10. Lipoprotein synthesis and secretion may be essential for this function: embryos lacking apolipoprotein (apo) B or microsomal triglyceride transfer protein (MTP), both of which participate in the assembly of triglyceride-rich lipoproteins, are apparently defective in their ability to export lipoproteins from yolk sac endoderm cells and die during mid-gestation. We therefore analyzed the embryonic expression of apoB, MTP, and alpha-tocopherol transfer protein (alpha-TTP), which have been associated with the assembly and secretion of apoB-containing lipoproteins in the adult liver, at different developmental time points. MTP expression or activity was found in the yolk sac and fetal liver, and low levels of activity were detected in E18.5 placentas. alpha-TTP mRNA and protein were detectable in the fetal liver, but not in the yolk sac or placenta. Ultrastructural analysis of yolk sac visceral endoderm cells demonstrated nascent VLDL within the luminal spaces of the rough endoplasmic reticulum and Golgi apparatus at E7.5 and E8.5. The particles were reduced in diameter at E13.5 and reduced in number at E18.5;-19. The data support the hypothesis that the yolk sac plays a vital role in providing lipids and lipid-soluble nutrients to embryos during the early phases (E7;-10) of mouse development. secretion in mouse yolk sac during embryonic development.

An acid amidase hydrolyzing anandamide as an endogenous ligand for cannabinoid receptors

Anandamide loses its cannabimimetic activities upon hydrolysis to arachidonic acid and ethanolamine. So far the anandamide hydrolyzing activity widely distributed in mammalian organs has been attributed exclusively to an enzyme referred to as anandamide amidohydrolase with an optimum pH around 9. We found another enzyme hydrolyzing anandamide in a human megakaryoblastic cell line (CMK). The enzyme present in the 12,000 x g pellet of the cell homogenate was solubilized by freeze-thaw. The solubilized enzyme showed an optimal pH around 5, and was almost inactive at alkaline pH. The enzyme activity was increased by the addition of dithiothreitol. In contrast, anandamide amidohydrolase of RBL-1 cells was mostly insoluble even after freeze-thaw, showed an optimal pH at 9, and was not affected by dithiothreitol. Furthermore, the enzyme of CMK cells was much less sensitive to phenylmethylsulfonyl fluoride and methyl arachidonoyl fluorophosphonate potently inhibiting anandamide amidohydrolase, and effectively hydrolyzed palmitoylethanolamide, which was a poor substrate for anandamide amidohydrolase. Thus, the enzyme of CMK cells is distinguishable from anandamide amidohydrolase.

Vitamin E protects against polymorphonuclear leukocyte-dependent adhesion to endothelial cells

We evaluated the effects of alpha-Toc on surface expression of CD11b/CD18 on polymorphonuclear leukocytes (PMN) stimulated with N-formyl-methionyl-leucyl-phenylalanine (fMLP) and oxidized low-density lipoprotein (oxLDL). Incubation of PMN with fMLP (1 microM) or oxLDL (100 microg/mL) increased CD11b/CD18 expression; pretreatment with alpha-Toc reduced in a dose-dependent manner. PMN obtained from healthy adults ingesting 600 mg alpha-Toc per day for 10 days were similarly incubated with fMLP or oxLDL; the surface level of CD11b/CD18 was inversely correlated with serum alpha-Toc concentrations. Adherence of PMN to human umbilical vein endothelial cells was increased by fMLP or oxLDL stimulation but reduced by alpha-Toc pretreatment or anti-CD18 monoclonal antibodies. cAMP-dependent protein kinase (PKA) and protein kinase C (PKC) activity in PMN was also assayed. A PKC inhibitor, but not a PKA inhibitor, suppressed CD11b/CD18 up-regulation, and alpha-Toc slightly decreased fMLP- and oxLDL-induced activation of PKC. These results suggest that alpha-Toc may prevent inflammation by both reducing CD11b/ CD18 up-regulation and decreasing PMN-dependent adherence to EC.

Oral tolerance is not influenced by oral application of oil-emulsified proteins

A 2-week program of feeding protein antigens as an oil-in-water emulsion to naive mice elicited a significant serum IgG antibody response, whereas their aqueous preparations did not at all. The unresponsive immune state that had been developed after feeding aqueous antigen was not disturbed by subsequent oral challenge with the same antigen in the presence of oil. These results suggest that the principle of oral tolerance is a feasible strategy for prophylaxis of hypersensitization to protein antigens, where protein tolerogens, in this case, are to be given without any additives at their first introduction.

alpha-Tocopherol protects against expression of adhesion molecules on neutrophils and endothelial cells

Leukocyte-endothelial cell interactions, which are mediated by various adhesion molecules, are a crucial event in inflammatory reactions including atherosclerosis. alpha-tocopherol (alpha-Toc) has been used for therapy of vascular diseases because of its antioxidant activity. However, the effect of alpha-Toc on inflammatory reactions has not been investigated very well. In the present study, we examined the effect of alpha-Toc on expression of adhesion molecules on human neutrophils and human umbilical vein endothelial cells (HUVEC). Expression of CD11a, CD11b and CD18 on neutrophils was assessed by immunofluorescence flow cytometry 30 min after the stimulation of neutrophils with 10(-7) M platelet-activating factor (PAF). Surface expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on HUVEC was evaluated by enzyme immunoassay 8 h after the incubation of HUVEC with IL-1 beta (20 U/ml). PAF induced upregulation of CD11b and CD18 on neutrophils and IL-1 beta increased surface expression of ICAM-1 and VCAM-1 on HUVEC. Coincubation of neutrophils with alpha-Toc and pretreatment of HUVEC with alpha-Toc significantly reduced PAF-induced CD11b/CD18 expression and IL-1 beta-induced upregulation of ICAM-1 and VCAM-1, respectively. These findings indicate that alpha-Toc may work as an anti-inflammatory agent through inhibiting neutrophil-endothelial cell adhesive reactions.

Acoustic properties of dialysed kidney by scanning acoustic microscopy

BACKGROUND

A correlation between acquired renal cysts in the dialysed kidney and renal cancer has long been debated, but no changes in the physical properties of kidneys at the microscopic level have been reported. The purpose of the present study was to classify the physical properties of the kidneys of patients undergoing haemodialysis at several stages of pathology by use of the scanning acoustic microscope.

METHODS

Sixteen surgically excised kidneys of dialysis patients were investigated. Tissues were fixed in 10% formalin, frozen in acetone, and cut 10 microns thick on a cryostat. We used a scanning acoustic microscope operated in the frequency range of 100-200 MHz. Attenuation constant and sound speed were measured on a two-dimensional distribution.

RESULTS

The attenuation constant for inflammatory granulation tissue was significantly higher than that for hyaline degeneration tissue (P < 0.001). Sound speed was high for granulation tissue, but tended to diminish gradually for hyaline degeneration. Sound speed increased again with progression to cystic degeneration (P < 0.001), but the attenuation constant remained low. When a cystic kidney contained a malignant lesion, the previously low attenuation constant rose at that site (P < 0.001), and the previously high sound speed was diminished (P < 0.001).

CONCLUSION

Our data suggest that the physical properties of dialysed kidneys at different stages of pathology can be classified by their acoustic properties. Simultaneous evaluation of attenuation constant and sound speed is considered applicable to determining whether tissues contain malignant elements.

Characterization of renal angiomyolipoma by scanning acoustic microscopy

A scanning acoustic microscope system was used to differentiate renal angiomyolipoma from renal cell carcinoma. The ultrasonic frequency used ranged from 100 to 200 MHz, and the attenuation constant and sound speed were measured on a two-dimensional distribution. The sound speed was significantly lower for lipoma cells than for vessels, smooth muscle fibres, clear cell renal cancer or granular cell renal cancer. The attenuation constant was significantly lower for lipoma cells than for vessels or clear cells. Both acoustic parameters for smooth muscle fibres were significantly lower than for vessels. The heterogeneity of the microacoustic field in renal angiomyolipoma is closely related to the high intensity echo observed on clinical echography. Renal angiomyolipoma and renal cell carcinoma can thus be distinguished by acoustic examination.

Some properties of inorganic pyrophosphatase from Bacillus subtilis

Inorganic pyrophosphatase (pyrophosphate phosphohydrolase, EC 3.6.1.1; PPase) from Bacillus subtilis was purified to a homogeneous state electrophoretically when analysed by SDS-PAGE. The enzyme consists of six identical subunits; the molecular weight of the native enzyme estimated by gel filtration was approx. 120,000, and denaturing polyacrylamide gel electrophoresis gave a single band corresponding to 24,000. The enzyme absolutely required a divalent cation for its activity. Mg2+ was most effective, showing two steps of concentration-dependent activation. Mg2+ could be partially replaced by Mn2+ and Co2+. The enzyme was thermostable in the presence of Mg2+, and no loss of activity was observed on the incubation at 55 degrees C for an hour.

Comparative study of cystic variations of the kidneys in haemodialysis and continuous ambulatory peritoneal dialysis patients

In recent years, many complications of renal cell carcinoma accompanying the increase in the number of peritoneal dialysis cases have been studied more often. Clinicopathologically, we studied comparatively cystic changes of the kidney, considered to be a background factor of cancerous development in 69 patients on peritoneal dialysis without past history of haemodialysis and in 192 patients on long-term haemodialysis. From the results, differences with respect to the duration of dialysis until the development of cysts and primary diseases commonly associated with cysts were not found between the two groups. Moreover, in the extirpated kidneys examined for cancerous development, cysts were found in both the peritoneal dialysis and the haemodialysis cases, and proliferative changes were found in the cystic epithelium. A relationship between cystic and cancerous development in the peritoneal dialysis cases was strongly suggested by these findings. Therefore, it was considered that careful follow-up studies for complications such as renal cell carcinoma would be necessary in both the peritoneal dialysis and the haemodialysis cases.

Influence of tissue preparation on the high-frequency acoustic properties of normal kidney tissue

The influence of various tissue preparations on the acoustic properties of normal kidney tissue at high frequencies was investigated. Eight surgically excised normal kidney tissue specimens were classified into three groups: (i) fresh, frozen section, (ii) formalin-fixed, frozen section and (iii) formalin-fixed, paraffin section. Scanning acoustic microscopy operating in the frequency range of 100-200 MHz was used to display the two-dimensional distribution of attenuation constant and sound speed. Our results indicate that (i) there is no significant variation in both acoustic parameters between the three tissue groups, (ii) fixation by 10% formalin produces no significant change in the acoustic parameters, (iii) in fat-free tissue regions, the acoustic parameters are independent of preparation method and (iv) frozen sections must be used to assess the acoustic parameters in fat-rich tissues.

Ultrasonic tissue characterization of renal cell carcinoma tissue

The purpose of this study was to characterize renal cell carcinoma tissue by the measurement of microacoustic properties. A scanning acoustic microscope system operating in the frequency range of 100-200 MHz was employed and the attenuation constant and sound speed were measured on the two-dimensional distribution. The values of attenuation constant and sound speed were lower in both kinds of cancer cells than those in normal kidney, although a significant difference was not found between the clear cell and granular cell. Also, both acoustic parameters of cancer cells were significantly lower than those in hemorrhage and fibrosis. These data suggest that the elasticity of renal cell carcinoma tissue may be lower than that of normal kidney. Moreover, the high intensity echo in clinical echography may be related to the heterogeneity of the microacoustic field in the carcinoma tissue.

Flow cytometric analysis of nuclear DNA content in the endoscopic biopsy tissues of gastric cancer

The nuclear DNA content was measured by flow cytometry in gastric cancer patients using endoscopically biopsied tissue specimens. When the specimens were classified into diploid and aneuploid according to the DNA histogram, 56% (65/117) of the specimens were aneuploid, and advanced cancer was clearly more often aneuploid than early cancer. The frequency of aneuploidy appeared to be higher as the histologic depth of cancer was greater. Noncancerous tissues of the stomach were mostly diploid. The nuclear DNA ploidy pattern in gastric cancer cells could be analyzed by using endoscopic biopsy samples and this flow cytometric investigation would be possibly contributive to further characterization of gastric cancer in the diagnostic procedure of malignancy.

Flow cytometric analysis of nuclear DNA content in tissues of colon cancer using endoscopic biopsy specimens

Flow cytometric assay of nuclear DNA in endoscopic biopsy specimens was evaluated in colon cancer patients. When the cells were divided into diploid cells and aneuploid cells, aneuploidy was observed in 63% (58 of 92) of the colon cancer patients. However, no clear relation was observed between the frequency of aneuploidy and the invasive depth, size, or histological type of colon cancer. Noncancerous portions of the colon tissues including colon adenoma or normal mucosa were mostly (96%, 87 of 91) diploid. Nuclear DNA content could be analyzed in the fresh biopsy specimens of colon cancer tissues and such investigation might be possibly valuable for further biological characterization of colon cancer in the usual procedure of clinical diagnosis for colonic malignancy before surgical operation or other treatment.

Observations on the growth rate of renal cell carcinoma

We retrospectively reviewed the records of 18 patients to investigate the growth rate of renal cell carcinoma (RCC). Growth rates were calculated from two or more gross measurements of neoplastic foci in the kidney (6 cases) and lung (12 cases). RCCs in primary sites grew slowly and the tumor volume doubling time (DT) raged from 372 to 579 days (468 +/- 84.6). Pulmonary metastases present in 12 cases grew rapidly, with a DT ranging from 20 to 154 days (89.4 +/- 43.0). Tumors in both the kidney and lung were composed of cancer cells with equal proliferative activity, as determined by immunohistochemical analysis of argyrophilic nucleolar organizer regions and proliferating cell nuclear antigen activity. Thus, our results suggest that, in addition to the proliferative activity of cancer cells, the microenvironment of the specific region is an important determinant of the growth rate of cancer cells.

Pyruvic acid production by an F1-ATPase-defective mutant of Escherichia coli W1485lip2

An F1-ATPase-defective mutant, TBLA-1, was constructed by the transduction of a defective gene for the alpha subunit of F1-ATPase, atpA401, into Escherichia coli W1485lip2, a lipoic acid-requiring pyruvic acid producer. The pyruvic acid production of the strain TBLA-1 was found to be improved markedly compared with that of strain W1485lip2. In cultures using a jar fermentor, the strain W1485lip2 consumed 50 g/liter of glucose and produced 25 g/liter of pyruvic acid after culture for 32h, while strain TBLA-1 consumed the same amount of glucose, and produced more than 30 g/liter of pyruvic acid in a 24-h culture. A revertant, No. 63-1, derived from the strain TBLA-1, had a normal level of F1-ATPase activity, and showed a similar pattern of pyruvic acid production to that of strain W1485lip2.

[Theoretical analysis about an optimal screening interval for renal cell carcinoma]

In recent years the number of incidentally detected renal cell carcinoma (RCC) has increased. It is undoubtedly true that ultrasonography is the most useful tool to detect RCC in small size. However, the optimal interval of ultrasound examination is unknown. To elucidate this, we investigated the growth rate of RCC during the period of non-treatment in 6 patients. Their growth was slow and the tumor volume doubling time ranged 372 to 579 (468 +/- 84.6) days. Based on this growth rate, we conclude that we can detect the majority of RCC ranging from 1.5 to 3 cm in diameter if ultrasonography is repeated every 3 years and that the age of subjects for screening is over 40 years.

Ultrasonic diagnosis of renal cell carcinoma in hemodialysis patients

From April 1985 to December 1992 abdominal ultrasonic examination was performed in 1,603 hemodialysis patients at our hospital. Renal cell carcinoma was found in 41 patients (2.6%), confirmed by nephrectomy as well as histology. This rate was 32 times greater than that of the general population (22 patients with renal cell carcinoma were detected among 27,933 at our health care center). Renal cell carcinoma was found in 18 patients with a contracted kidney, 19 with acquired cystic disease of the kidney and 4 with a native kidney after renal transplantation. Among 19 patients with acquired cystic disease of the kidney 8 had unilateral multiple tumors and 5 bilateral multiple tumors. The detection rate of renal cell carcinoma was 100% by ultrasonography, 67% by computerized tomography and 56% by angiography. Ultrasonography was the most accurate examination for the diagnosis of renal cell carcinoma in hemodialysis patients.

Renal cell carcinoma associated with chronic renal failure: evaluation with sonographic angiography

PURPOSE

To determine the value of sonographic angiography for diagnosis of renal cell carcinoma (RCC) in patients with chronic renal failure (CRF).

MATERIALS AND METHODS

The authors compared findings from sonographic angiography, conventional ultrasound (US), computed tomography (CT), and conventional angiography in 15 patients with CRF in whom RCC was suspected. All of these patients subsequently underwent nephrectomy.

RESULTS

RCC was demonstrated pathologically in 13 patients, whereas two had benign lesions only. Sonographic angiography depicted tumor enhancement in all patients with RCC except one; no enhancement was shown in the two patients with benign lesions. Conventional angiography depicted tumors stained by contrast material in nine of 13 patients with RCC, and CT depicted tumor enhancement in 10 of 13 patients. US was useful for the detection of nodules but did not allow differentiation of malignant from benign lesions.

CONCLUSION

Sonographic angiography has a possible role in the detection of small nodules in patients with CRF.

Renal cell carcinoma in dialysis patients

Histopathological studies were performed in 18 dialysis patients with renal cell carcinoma. All patients were classified as stage I according to the criteria in the protocol of Robson. The 2 main cell types in these patients were granular (50%) and clear (44%) cell tumors. Thirty-nine percent of the carcinomas exhibited a predominantly acinar growth pattern, 27% had a papillary, and 17% exhibited a cystic growth pattern. In 28 nondialysis patients, the commonest cell type was clear cell carcinoma (67%) and acinar growth pattern was the predominant one (67%). The incidence of papillary renal cell tumors in dialysis patients was significantly higher than in nondialysis patients (p < 0.05). Patients with papillary renal cell tumors had received longer duration of dialysis therapy than those with nonpapillary renal cell carcinomas (p < 0.05). Seven (39%) showed grade 1 carcinoma and 11 (61%) showed grade 2, but grade 3 carcinoma was not observed. In these patients, 8 had associated acquired cystic disease of the kidney (ACDK). The duration of dialysis in the patients with ACDK was significantly longer (p < 0.001). The most frequent cell type was granular-cell carcinoma (63%) in the patients with ACDK. Six patients without ACDK (60%) showed clear-cell carcinoma and 4 (40%) had granular cell tumors. Seventy-four percent of carcinomas exhibited a predominantly either papillary or cystic growth pattern in the patients with ACDK. However, renal cell carcinomas in dialysis patients with or without ACDK did not show significant differences in growth pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

[Ultrasonic diagnosis of renal cell carcinoma in hemodialysis patients]

Abdominal ultrasonic examination (US) was performed in 1556 patients on hemodialysis for 7 years and 6 months from April 1955 to September 1992. Renal cell carcinoma (RCC) proved histologically by operation was found in 36 patients (41 kidneys). Among the 36, RCC developed from the contracted kidney in 15, the individual kidney after renal transplantation in 3, and from ACDK (acquired cystic disease of the kidney) in 18. Among the 18 (ACDK), multiple tumors were found in the unilateral kidney in 8 and in bilateral kidney in 5. RCC was detected at the rate of 2.3% in patients on hemodialysis (1 out of 43). It was 29 time as high as in healthy persons (RCC was found in 22 out of 27933 at our Health Check-up Center, 0.079%). RCC was diagnosed 100% by US, 68% by CT, and 55% by angiography. US is the most excellent examination for the diagnosis of RCC in patients on hemodialysis.

Differentiation of transiently ischemic from infarcted myocardium by thallium-201 exercises scintigram after active ergometer rehabilitation

It has been frequently reported that while myocardial viability is neglected in conventional methods of diagnosis such as left ventriculography, ECG, and exercise thallium-201 myocardial scintigraphy (Ex-Tl), revascularization often results in improving left ventricular wall motility. In the present study, the authors contrived a method to accurately evaluate the viability of the myocardium by means of exercise rehabilitation, and tested the method in clinical cases. Among patients with myocardial infarction, we selected a patient with negative viability in the diseased area as determined by chronic ECG, left ventriculography (LVG), coronary angiography and Ex-Tl. This patient went through two weeks of active exercise rehabilitation gauged with an ergometer, and was then re-examined by Ex-Tl. After the evaluation, revascularization was performed for the patient who demonstrated viability of the infarcted myocardium in EX-Tl after rehabilitation, and significant improvement in contractility was shown in the chronic LVG. These findings indicate that our method of detecting potential viability of the infarcted myocardium is of clinical significance.

Renal cell carcinoma in chronic renal failure without dialysis treatment

We report a case of renal cell carcinoma in chronic renal failure without dialysis treatment. The literature is reviewed, and the relationship between renal cell carcinoma and uraemia is discussed.