Formate-producing capacity provided by reducing ability of Streptococcus thermophilus nicotinamide adenine dinucleotide oxidase determines yogurt acidification rate

Yogurt is made by fermenting milk with 2 lactic acid bacteria, Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus. To comprehensively understand the protocooperation mechanism between S. thermophilus and L. bulgaricus in yogurt fermentation, we examined 24 combinations of cocultures comprising 7 fast- or slow-acidifying S. thermophilus strains with 6 fast- or slow-acidifying L. bulgaricus strains. Furthermore, 3 NADH oxidase (Nox)-deficient mutants (Δnox) and one pyruvate formate-lyase deficient mutant (ΔpflB) of S. thermophilus were used to evaluate the factor that determines the acidification rate of S. thermophilus. The results revealed that the acidification rate of S. thermophilus monoculture determined the yogurt fermentation rates, despite the coexistence of L. bulgaricus, whose acidification rate was either fast or slow. Significant correlation was found between the acidification rate of S. thermophilus monoculture and the amount of formate production. Result using ΔpflB showed that the formate was indispensable for the acidification of S. thermophilus. Moreover, results of the Δnox experiments revealed that formate production required Nox activity, which not only regulated dissolved oxygen, but also the redox potential. The Nox provided the large decrease in redox potential required by pyruvate formate-lyase to produce formate. A highly significant correlation was found between formate accumulation and Nox activity in S. thermophilus. In conclusion, the formate production ability provided by the action of Nox activity determines the acidification rate of S. thermophilus, and consequently, regulates yogurt coculture fermentation.

Cultivation of rice for animal feed with circulated irrigation of treated municipal wastewater for enhanced nitrogen removal: comparison of cultivation systems feeding irrigation water upward and downward

To achieve enhanced nitrogen removal, we modified a cultivation system with circulated irrigation of treated municipal wastewater by using rice for animal feed instead of human consumption. The performance of this modified system was evaluated through a bench-scale experiment by comparing the direction of circulated irrigation (i.e. passing through paddy soil upward and downward). The modified system achieved more than three times higher nitrogen removal (3.2 g) than the system in which rice for human consumption was cultivated. The removal efficiency was higher than 99.5%, regardless of the direction of circulated irrigation. Nitrogen in the treated municipal wastewater was adsorbed by the rice plant in this cultivation system as effectively as chemical fertilizer used in normal paddy fields. Circulated irrigation increased the nitrogen released to the atmosphere, probably due to enhanced denitrification. Neither the circulation of irrigation water nor its direction affected the growth of the rice plant and the yield and quality of harvested rice. The yield of rice harvested in this system did not reach the target value in normal paddy fields. To increase this yield, a larger amount of treated wastewater should be applied to the system, considering the significant amount of nitrogen released to the atmosphere.

Establishment of pure NOTES procedure using a conventional flexible endoscope: review of six cases of gastric gastrointestinal stromal tumors

An increasing number of reports have recently been published on hybrid natural orifice transluminal endoscopic surgery (NOTES). These reports do not address how to complete an operation with a flexible endoscope alone (pure NOTES), but rather how to combine use of an endoscope and a laparoscope. Surgical procedures using flexible and rigid endoscopes have been developed using different processes and concepts. Recognizing this conceptual difference, we conducted a study to address how to establish a pure NOTES procedure. Six patients with gastric gastrointestinal stromal tumors (GISTs) underwent hybrid NOTES. Each case was retrospectively reviewed to determine the appropriateness of the treatment and the usefulness of the endoscopic submucosal dissection (ESD) method, double-scope method, spaced perforation method, duodenal balloon occlusion method, and loop clip technique. The development of operative procedures that take advantage of the characteristics of flexible endoscopes, even with conventional flexible endoscopic devices and conventional endoscopes alone, may contribute to the realization of pure NOTES.

Strongly correlated fermions after a quantum quench

Using the adaptive time-dependent density-matrix renormalization group method, we study the time evolution of strongly correlated spinless fermions on a one-dimensional lattice after a sudden change of the interaction strength. For certain parameter values, two different initial states (e.g., metallic and insulating) lead to observables which become indistinguishable after relaxation. We find that the resulting quasistationary state is nonthermal. This result holds for both integrable and nonintegrable variants of the system.

Evaluation of treatment for gastro-oesophageal reflux disease with a proton pump inhibitor, and relationship between gastro-oesophageal reflux disease and Helicobacter pylori infection in Japan

BACKGROUND

Effective therapy for gastro-oesophageal reflux disease (GERD) is associated with improvement in health-related quality of life. It remains unclear whether Helicobacter pylori infection protects against GERD.

AIM

We evaluated the relationship between GERD and H. pylori, and whether the health-related quality of life score improved after medical treatment.

METHODS

We enrolled 151 outpatients with upper abdominal symptoms; 81 patients received omeprazole 20 mg/day for 2 weeks. Health-related quality of life was assessed using the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) index. H. pylori infection was diagnosed by serum antibody or endoscopy and the relationship between GERD and H. pylori was evaluated.

RESULTS

In GERD patients, the mean GSRS score improved from 2.20 to 1.67 following treatment (P < 0.01). The mean GSRS reflux symptom score improved from 2.96 to 1.67 (P < 0.01). The mean PGWB score improved from 96.36 to 107.34 (P < 0.01). All scores in GERD patients significantly improved compared with non-GERD patients. The H. pylori-positive ratio was 66.15% in GERD patients and 65.21% in non-GERD patients (P = 0.94).

CONCLUSIONS

Health-related quality of life is useful for evaluation of proton pump inhibitor treatment in GERD. The presence of H. pylori was not associated with the prevalence of GERD.

Autoimmune hepatitis in a patient with systemic lupus erythematosus

We report a female patient with systemic lupus erythematous (SLE), hyperbilirubinemia and high serum value of ALT. International autoimmune hepatitis (AIH) score showed definite AIH before treatment, but autoantibodies could not make a differential diagnosis of AIH and SLE-associated hepatitis. Liver biopsy showed periportal hepatitis with lymphoplasmacytic infiltration, but neither parenchymal collapse nor rosette formation could be found. Pericarditis, pleuritis and nephritis were improved as well as liver injury after administration of prednisolone, and no repeated attack has been present these 4 years. Our case suggested invalidity of AIH score among patients of SLE, and liver histology should be inferred most important at present to make a differential diagnosis of lupus hepatitis or AIH in patients with SLE.

[Mucosa-associated lymphoid tissue lymphoma; report of two cases]

Primary pulmonary malignant lymphoma is a rare disease that is thought to belong to a category of malignant lymphomas arising from mucosa-associated lymphoid tissue (MALT). We presented 2 cases of MALT lymphoma. Case 1: In a 39-year-old woman, an abnormal shadow was detected in chest radiography in the left S3. The diagnosis was organizing pneumonia in consequence of the further examination. One year after an growing abnormal shadow was detected again, we performed the tumor resection with the thoracoscopy in the possibility of malignancy. The pathological diagnosis was MALT lymphoma. Case 2: In a 70-year-old man, middle lobe syndrome was detected in chest radiography. As a result of the bronchial biopsy, the lesion was suspected of MALT lymphoma. Right middle lobectomy was performed, and the tumor was diagnosed as a MALT lymphoma histologically. He underwent an effective postoperative radiotherapy and has had no evidence of recurrence.

Local quantum criticality in confined fermions on optical lattices

Using quantum Monte Carlo simulations, we show that the one-dimensional fermionic Hubbard model in a harmonic potential displays quantum critical behavior at the boundaries of a Mott-insulating region. A local compressibility defined to characterize the Mott-insulating phase has a nontrivial critical exponent. Both the local compressibility and the variance of the local density show universality with respect to the confining potential. We determine a generic phase diagram, which allows the prediction of the phases to be observed in experiments with ultracold fermionic atoms trapped on optical lattices.

Association of the HLA-DRB1 gene locus with gastric adenocarcinoma in Japan

BACKGROUND AND AIM

Helicobacter pylori infection is associated with gastric adenocarcinoma, however, the odds ratio is relatively low. The aim of the present study was to investigate host genetic factors that increase the risk of gastric adenocarcinoma among H. pylori-infected individuals.

METHODS

A total of 70 patients with early gastric adenocarcinoma and 121 unrelated healthy controls were examined for H. pylori infection and HLA-DRB1 genotyping. The frequencies of HLA-DRB1 alleles were compared among groups.

RESULTS

The allele frequency of DRB1*04051 was significantly higher in patients with gastric adenocarcinoma (17.9%) than in controls (7.9%) (P(correct) = 0.045). The odds ratio of gastric adenocarcinoma associated with the presence of the HLA-DRB1*04051 allele compared with its absence was 2.55 (95% confidence limits, 1.35-4.83). This genetic risk was not associated with H. pylori infection. There was no significant difference in the HLA-DRB1 allele frequency between H. pylori-positive and H. pylori-negative controls. The frequency of genotypes that possessed the DRB1*04051 allele in gastric adenocarcinoma patients (34.3%) was significantly higher than that in H. pylori-negative controls (11.9%) (p = 0.0089) and H. pylori-positive controls (15.2%) (p = 0.0066).

CONCLUSION

These findings suggest that immunogenetic factors for susceptibility to gastric adenocarcinoma are present in the host, the HLA-DRB1*04051 allele is a host genetic risk factor for gastric adenocarcinoma, and that this genetic risk is independent of H. pylori infection.

Antiholons in one-dimensional t-J models

Using a newly developed hybrid Monte Carlo algorithm for the nearest-neighbor (nn) t-J model, we show that antiholons identified in the supersymmetric inverse squared (IS) t-J model are clearly visible in the electron-addition spectrum of the nn t-J model at J=2t and also for J=0.5t, a value of experimental relevance.

Mott domains of bosons confined on optical lattices

In the absence of a confining potential, the boson-Hubbard model exhibits a superfluid to Mott insulator quantum phase transition at commensurate fillings and strong coupling. We use quantum Monte Carlo simulations to study the ground state of the one-dimensional bosonic Hubbard model in a trap. Some, but not all, aspects of the Mott insulating phase persist. Mott behavior occurs for a continuous range of incommensurate fillings, very different from the unconfined case, and the establishment of the Mott phase does not proceed via a traditional quantum phase transition. These results have important implications for interpreting experiments on ultracold atoms on optical lattices.

Thoracoscopic treatment for spontaneous hemopneumothorax

Spontaneous hemopneumothorax is a rare clinical entity sometimes requiring an operation in the early stage. Two patients who underwent successful video-assisted thoracic surgery (VATS) for spontaneous hemopneumothorax are presented. In both cases, the bleeding point was clearly identified, and hemostasis was easily obtained by clipping the point and placing three access ports in the usual fashion. Furthermore, the evacuation of clotted blood and resection of bulla were performed with no difficulties. The postoperative courses were smooth, and no complications occurred, although the preoperative general condition in the second case was hemodynamically unstable. The advantages of VATS over conventional thoracotomy include less time required to access the pleural cavity, a better view, and more facilitated manipulation during surgery. Because spontaneous hemopneumothorax is a benign disease, VATS should be considered an initial treatment option in all patients with this condition, even those with active bleeding.

Immunohistochemical localization of CEA, CA19-9 and DU-PAN-2 in hepatitis C virus-infected liver tissues

AIMS

We investigated expression of CEA, CA19-9 and DU-PAN-2 in liver tissues of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma, measuring their serum value to clarify their clinical significance, and proliferating cell nuclear antigen (PCNA) was assessed in serial sections to determine whether expression of these molecules in chronic liver disease was related to regeneration of biliary ducts.

METHODS AND RESULTS

Liver tissues were biopsied under peritoneoscopy or echo-guidance and resected surgically among 63 patients with anti-hepatitis C virus-positive sera. There were 26 cases of chronic hepatitis, 21 cases of liver cirrhosis and 16 cases of hepatocellular carcinoma (four cases of mixed type). They were simultaneously used for immunocytochemistry for CEA, CA19-9 and DU-PAN-2, and PCNA was demonstrated in serial liver tissues by immunohistochemistry. Serum CEA, CA19-9 and DU-PAN-2 were measured by radioimmunoassay or enzyme immunoassay. In chronic hepatitis and liver cirrhosis CEA immunoreactivity was seen on membranes facing bile canaliculi and in bile ductules. Both CA19-9 and DU-PAN-2 immunoreactivity were observed in bile ductules in chronic hepatitis liver cirrhosis and non-neoplastic areas surrounding hepatocellular carcinoma, and CA19-9 was also present in interlobular bile ducts. PCNA immunoreactivity was not detected in marker-positive bile ductules or interlobular bile ducts. In hepatocellular carcinoma CEA immunoreactivity was seen on membrane facing dilated bile canaliculi in glandular structures, and CEA, CA19-9 and DU-PAN-2 immunoreactivity was observed in cholangiolar areas in mixed type of hepatocellular carcinoma.

CONCLUSIONS

CEA in chronic hepatitis and liver cirrhosis is expressed not only in bile ductules but also on membrane facing bile canaliculi, and both CA19-9 and DU-PAN-2 were seen in different levels of biliary ducts. These molecules were expressed in bile ductules in surrounding non-neoplastic areas of hepatocellular carcinoma, and their expression was not associated with regeneration of biliary ducts. CEA expression was present in the trabecular type of hepatocellular carcinoma, and CA19-9 and DU-PAN-2 were observed in cholangiolar areas in mixed type of hepatocellular carcinoma.

Eradication of Helicobacter pylori infection induces an increase in body mass index

BACKGROUND

The relationship between H. pylori infection and body mass indices is controversial.

AIM

To investigate the relationship between H. pylori infection and body indices, and to examine the effect of H. pylori eradication therapy on body indices.

METHODS

Nine-hundred and thirty-two employees of an industrial corporation were examined for H. pylori infection and body mass indices. Three hundred and two H. pylori-positive cases diagnosed with chronic gastritis by upper gastrointestinal endoscopy or radiography underwent eradication therapy. Body mass indices, serum total cholesterol levels and symptom scores were obtained before and at 12 months after eradication therapy.

RESULTS

There was no significant difference in body weight, body mass index (BMI) or serum total cholesterol level between the H. pylori-positive and H. pylori-negative groups. However, body weight and BMI increased significantly 12 months after eradication of H. pylori infection. In contrast, there was no significant difference in body weight and BMI 12 months after eradication therapy in the non-eradication group. Serum total cholesterol levels did not change after eradication therapy in either the eradication or non-eradication groups.

CONCLUSION

Eradication of H. pylori infection induced an increase in BMI in industrial workers with chronic gastritis in Japan.

Investigation of parenchymal cell differentiation in organotypic slice culture of mouse fetal liver under administration of sodium butyrate

The fetal mouse liver tissues in our organotypic slice culture were spread and flattened for at least 3 weeks; small, round cells were distributed in the center and polygonal cells were seen in the periphery. Ultrastructurally, polygonal cells showed abundant rough endoplasmic reticulum and mitochondria. They expressed albumin (ALB) and alpha-fetoprotein (AFP) for at least 3 weeks, and Cx32-immunoreactivity was also seen in a plaque on the cells. Many proliferating cell nuclear antigen (PCNA)-positive cells were observed at the periphery, and there were scattered CK-19-positive cells. The spreading of the fetal liver tissue in organotypic slice culture was reduced in medium containing sodium butyrate (SB). The expression of ALB was well maintained in polyglonal cells of the SB(+) group 3 weeks after culture and AFP-immunoreactivity was decreased in the SB(+) group. The concentration of ALB in the medium was significantly higher in the SB(+) than in the SB(-) group. CK-19-positive cells in the SB(+) group were increased in number more than those in the SB(-) group. PCNA-positive cells were less numerous in the SB(+) group, and Cx32-positive plaques were increased. SB can help immature hepatocytes to differentiate into the mature type and the cholangiocytic lineage, reducing their proliferation. These findings suggest that parenchymal cells in our organotypic slice culture of the fetal mouse liver can maintain structure and function as in vivo for the long term, and SB is shown to be a differentiation inducer of parenchymal cells in the slice culture.

Effects of CYP2C19 gene polymorphism on cure rates for Helicobacter pylori infection by triple therapy with proton pump inhibitor (omeprazole or rabeprazole), amoxycillin and clarithromycin in Japan

BACKGROUND

Omeprazole is mainly metabolized by cytochrome P450 2C19 (CYP2C19) in the liver. Rabeprazole, on the other hand, is mainly metabolized to thioether-rabeprazole via a non-enzymatic pathway and partially metabolized to demethylated-rabeprazole by CYP2C19 in liver CYP2C19 status may affect cure rate for Helicobacter pylori infection with proton pump inhibitor triple therapy.

AIM

To investigate whether genetic polymorphism of CYP2C19 and selected proton pump inhibitors (omeprazole or rabeprazole) were associated with cure rate for Helicobacter pylori infection using triple therapy with omeprazole or rabeprazole, amoxicillin, and clarithromycin.

METHODS

A total of 170 Helicobacter pylori-positive patients with chronic gastritis were randomized to receive one of the following Helicobacter pylori eradication regimens; OAC (omeprazole 20 mg bd, amoxycillin 750 mg bd and clarithromycin 400 mg bd for 1 week) and RAC (rabeprazole 20 mg bd, amoxycillin 750 mg bd and clarithromycin 400 mg bd for 1 week). The CYP2C19 genotype; wild-type or two mutant genes (ml in exon 5 and m2 in exon 4), or both, were identified by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

In DAC regimen, cure rate (per protocol analysis) was 73.3% in homozygous extensive metabolizers, 86.1% in heterozygous extensive metabolizers, and 85.0% in poor metabolizers. In RAC regimen, the cure rate was 81.0% in homozygous extensive metabolizers, 82.9% in heterozygous extensive metabolizers, and 87.5% in poor metabolizers. Cure rate was not significantly different between the CYP2C19 genotypes in both regimens.

CONCLUSION

Triple therapy with proton pump inhibitor (omeprazole or rabeprazole), amoxycillin, and clarithromycin is sufficiently effective in cure of Helicobacter pylori infection regardless of CYP2C19 status.

The effect of Helicobacter pylori eradication therapy on dyspepsia symptoms in industrial workers in Japan

BACKGROUND

The relationship between Helicobacter pylori infection and non-ulcer dyspepsia is still controversial. The potential benefits and risks of the treatment could depend on local conditions, such as the prevalence of the infection and the local rates of gastric cancer.

AIM

To evaluate the effects of H. pylori eradication therapy on non-ulcer dyspepsia symptoms in industrial workers in Japan.

METHODS

A total of 615 employees of an industrial corporation were examined for H. pylori infection and symptom scores; 215 H. pylori-positive non-ulcer dyspepsia cases underwent eradication therapy. Symptom scores were also analysed 12 months after the eradication therapy. Serum pepsinogen A and pepsinogen C levels were analysed and chronic atrophic gastritis was serologically diagnosed on the basis of the criteria of a pepsinogen A < 70 ng/mL and pepsinogen A : pepsinogen C ratio < 3.0.

RESULTS

The symptom score improved significantly in the cured cases, but not in the non-cured cases. The effect of the cure of H. pylori infection on symptoms was analysed according to the serological diagnosis of chronic atrophic gastritis. In both groups, cases with atrophic gastritis and cases with chronic gastritis only, the cure of infection was effective in improving symptoms.

CONCLUSION

The cure of H. pylori infection was effective in reducing non-ulcer dyspepsia symptoms in industrial workers in Japan.

Targeted killing of carcinoembryonic antigen (CEA)-producing cholangiocarcinoma cells by polyamidoamine dendrimer-mediated transfer of an Epstein-Barr virus (EBV)-based plasmid vector carrying the CEA promoter

The present study reports a novel nonviral method to efficiently and specifically target carcinoembryonic antigen (CEA)-producing cholangiocarcinoma (CC) cells in vitro. Epstein-Barr virus (EBV)-based and conventional plasmid vectors were constructed that possess the beta-galactosidase (beta-gal) or herpes simplex virus-1 (HSV-1) thymidine kinase (Tk) genes as well as tandem repeats of the human genomic sequence -82 to -42 bp from the transcriptional start site of the CEA gene. The plasmids were transfected by means of polyamidoamine dendrimer into CEA-positive (HuCC-T1) or -negative cell lines. Transfection of the conventional plasmid vector with the CEA promoter and beta-gal gene resulted in a very low or undetectable level of marker gene expression even in the CEA-positive cell line. Transferring the HSV-1 Tk gene by conventional plasmid did not affect the susceptibility of HuCC-T1 cells to ganciclovir. In marked contrast, strong beta-gal expression was specifically obtained in HuCC-T1 cells by transfecting the EBV-based plasmid in which the CEA promoter and a ubiquitous promoter (SRalpha) are employed to drive the EBV-encoded nuclear antigen 1 (EBNA1) and beta-gal genes, respectively (pTES.beta). Furthermore, CEA-positive but not -negative tumor cells were rendered highly susceptible to ganciclovir when transfected with the EBV-based vector that carries the CEA promoter-EBNA1 and SRalpha-HSV-1 Tk genes (pTES.Tk). These results strongly suggest that the EBV-based plasmid vector/cationic polymer system (EBV/polyplex) equipped with the CEA promoter provides an efficient nonviral method for the targeted gene therapy of CEA-producing malignancies.

Pyruvate dehydrogenase activity and energy metabolite levels following bilateral common carotid artery occlusion in rat brain

The influence of chronic cerebral hypoperfusion on cerebral energy metabolism was studied. The bilateral common carotid arteries of Wistar rats were occluded for 0, 2, 7, and 28 days. Cerebral energy metabolism was evaluated by assaying adenosine triphosphate (ATP), phosphocreatine (PCr), and lactate levels and measuring pyruvate dehydrogenase (PDH) activity (each time point, n = 6). Pathological changes were assessed light-microscopically by Klüver-Barrera staining and immunohistochemical labeling for astroglia (each time point, n = 3). There were no changes in ATP and PCr levels or PDH activity; there was slight but significant transient lactate accumulation at 2 days. Myelin pallor and increase in immuno-reactive astroglia were only observed at 28 days. These results indicate that chronic cerebral hypoperfusion induces delayed white matter changes in the corpus callosum of rat brain, but does not affect energy production.

Development of gap junctional channels and intercellular communication in rat liver during ontogenesis

BACKGROUND/AIMS

We investigated the expression of connexin (Cx) 32 and 26 subunit proteins of the gap junction (GJ) in the rat liver during ontogenesis to clarify their roles in control of growth and differentiation, and observed their channels in association with development of gap junctional intercellular communication (GJIC).

METHODS

The expression of Cx32 and 26 in prenatal and postnatal livers was examined by Western blot and immunofluorescence. GJ channels were investigated not only by double immunofluorescence study but also by immunogold electron microscopy. The spread of lucifer yellow 5 min after its microinjection was examined in the cultured liver tissues.

RESULTS

1) Western blot showed the expression of both Cx from the late stage of gestation and their peak a week after birth. 2) Cx32- or 26-positive plaques were scattered on hepatocytes of the fetal liver and some of them were colocalized; both were increased just after birth. On day 7 after birth, Cx32-positive plaques were present on all hepatocytes within a lobule, and Cx26-positive plaques were distributed in the periportal area. 3) Double-immunogold electron microscopy just after birth showed that most GJ channels were homotypic type of Cx32 or 26, and that few were heterotypic. On day 7 after birth, most channels had the homotypic type of type of Cx32 in the middle and pericentral areas, and there was a heterotypic type of Cx32 and 26 in the periportal area. 4) The dye transfer of lucifer yellow showed a wider spread in the liver tissues on day 7 after birth than on day 1.

CONCLUSION

Increased GJ formation and compatibility or incompatibility of GJ channels are closely associated with development of GJIC, and GJIC may develop at cytodifferentiation during ontogenesis.

Parenchymal cells proliferate and differentiate in an organotypic slice culture of the neonatal liver

We applied organotypic slice culture of neonatal mouse liver tissues to maintain the parenchymal cells in ontogenesis and to investigate their proliferation and differentiation. Cultured tissue spread gradually over 3 weeks. Small basophilic cells formed several layers in the center of the cultured tissues, and a monolayer of polygonal cells was seen at the periphery. Albumin- and alpha-fetoprotein-immunoreactions were seen in polygonal cells, as were proliferating cell nuclear antigen-immunoreactions. Connexin 32- and 26-immunoreactions were observed in small plaques on the membrane of the polygonal cells, and electron microscopy showed gap junctional complexes. Ultrastructurally, polygonal cells had a round nucleus and abundant cytoplasmic organelles, and bile canaliculi were seen on the cytoplasmic membrane. Cytokeratin 19-immunoreactions were scattered in clusters. There were ultrastructurally bile-duct-like structures with microvilli on the inner surface of the cavity and tight junctions between their constituent cells. Quantitative analysis of albumin-, alpha-fetoprotein- and cytokeratin 19- or proliferating cell nuclear antigen-immunoreactivity in parenchymal cells showed changes of their phenotypes or maintenance of their proliferation in tissue culture. Our slice-culture system enabled us to maintain and to develop parenchymal cells in the liver tissue for at least 3 weeks. The findings suggest that organotypic slice culture applied to liver tissues in ontogenesis may be a useful tool not only to maintain parenchymal cells but also to investigate their proliferation and differentiation.

Steady-state propofol brain:plasma and brain:blood partition coefficients and the effect-site equilibration paradox

Based on volume-flow relationships, CNS agents that are highly lipid soluble (log octanol-water partition coefficient > 2) are expected to have equilibration half-times (T1/2 kE0) that are proportional to brain solubility. Propofol, the most lipophilic anaesthetic in clinical use, has T1/2 kE0 values of 1.7 and 2.9 min in rats and humans, respectively, compared with an expected value of at least 8 min. As a first step in exploring this discrepancy between observed and predicted values, we determined the steady state brain:plasma and brain:blood partition coefficients in rats after a 4-h infusion of propofol. Brain:plasma and brain:blood partition coefficients were 8.2 (SD 1.6) and 3.0 (0.5), respectively. T1/2 kE0 predictions based on brain: blood partitioning in rats are more in agreement with the observed equilibration half-time, suggesting that drug bound to the formed elements of blood participates in the uptake and transfer of propofol to its effect site.

Increased expression of the sodium/iodide symporter in papillary thyroid carcinomas

Iodide is concentrated to a much lesser extent by papillary thyroid carcinoma as compared with the normal gland. The Na+/I- symporter (NIS) is primarily responsible for the uptake of iodide into thyroid cells. Our objective was to compare NIS mRNA and protein expression in papillary carcinomas with those in specimens with normal thyroid. Northern blot analysis revealed a 2.8-fold increase in the level of NIS mRNA in specimens with papillary carcinoma versus specimens with normal thyroid. Immunoblot analysis using anti-human NIS antibody that was produced with a glutathione S-transferase fusion protein containing NIS protein (amino acids 466-522) showed the NIS protein at 77 kD. The NIS protein level was elevated in 7 of 17 cases of papillary carcinoma but was not elevated in the normal thyroid. Immunohistochemical staining revealed abundant NIS in 8 of 12 carcinomas, whereas NIS protein was barely detected in specimens with normal thyroid. Although considerable patient-to-patient variation was observed, our results indicate that NIS mRNA is elevated, and its protein tends to be more abundant, in a subset of papillary thyroid carcinomas than in normal thyroid tissue.

Unilateral meningoencephalitis with hemispheric slowing on EEG

We report a 12-year-old boy with unilateral meningoencephalitis due to non-herpes simplex virus. He experienced secondarily generalized partial seizures of the left extremities with loss of consciousness. In contrast with normal neuroimaging findings, interictal electroencephalograms (EEGs) showed prolonged slowing in the right hemisphere. This laterality agreed with the right brain dysfunction verified on neuropsychological examination. Follow-up EEG is important in such a subtle case with normal neuroimaging.

Formation Mechanism of Monodispersed alpha-Fe2O3 Particles in Dilute FeCl3 Solutions

Some ambiguity is still involved in the interpretation of the growth mechanism of monodispersed hematite (alpha-Fe2O3) particles in dilute FeCl3 solutions. Namely, there are two entirely different proposals on this issue, viz. aggregation of preformed primary particles of alpha-Fe2O3 itself and reprecipitation of the ionic species through dissolution of the preformed beta-FeOOH particles. In order to resolve this problem, the formation process was followed in detail through TEM, Electron Diffraction, XRD, FT-IR, and ICP spectrometry along with quantitative analyses on seed effects. As a result, it has been concluded that the nuclei of the hematite particles are initially generated with the formation of beta-FeOOH particles and that they are grown by deposition of the solute originally present in the solution phase and indirectly furnished from the beta-FeOOH by dissolution. As the concentration of the solute is lowered by the growth of the hematite particles, they continue to grow with the solute provided mainly from the beta-FeOOH in a steady-state of the dissolution of beta-FeOOH and growth of alpha-Fe2O3. The basic formation mechanism is common to the ellipsoidal particles grown in the presence of phosphate ions and spherical particles in their absence.

[A case of ACTH-producing thymic carcinoid tumor with Cushing syndrome]

ACTH-producing thymic carcinoid tumor with Cushing syndrome in a 41-year-old male was reported. Plasma ACTH and cortisol was high, and chest X-ray film and CT scan revealed a tumor mass in the anterior mediastinum. Extended thymectomy with pretracheal lymph node dissection was performed. The microscopic findings revealed that the mass was carcinoid tumor with metastasis of anterior mediastinal lymph node. ACTH and cortisol were restored to normal range 1 week after operation. Unfortunately, he admitted seven months later because of high level of ACTH and right supraclavicular lymph nodes swelling. He underwent right neck dissection. Pathological examination proved metastatic carcinoid tumors in the dissected nodes. It is important to perform supraclavicular lymph node dissection together with extended thymectomy for thymic carcinoid tumor.

Immunohistochemical, electron microscopic, and immunoelectron microscopic features of plasmacytoma of the thyroid with amyloid deposition

A rare case of primary plasmacytoma of the thyroid with amyloid deposition is reported. The tumor consisted of diffuse proliferation of atypical plasma cells showing IgG lambda-type monoclonal growth. Amyloid deposition with focal giant cell reaction was also observed. Bone marrow aspiration and systemic skeletal radiographic surveys revealed no evidence of multiple myeloma and myelomatosis. Radial arrangement of amyloid bundles was observed ultrastructurally. By immunoelectron microscopic examination, lambda chain was detected in the amyloid fibrils and rough endoplasmic reticulum of the tumor cells. Our findings suggest the following: amyloid fibrils originate from monoclonal light chains produced by tumor cells, and histiocytes contribute to amyloid deposition as well as to giant cell reaction in extramedullary plasmacytoma.

Genetic improvement of Escherichia coli for enhanced biological removal of phosphate from wastewater

The ability of Escherichia coli MV1184 to accumulate inorganic phosphate (Pi) was enhanced by manipulating the genes involved in the transport and metabolism of Pi. The high-level Pi accumulation was achieved by modifying the genetic regulation and increasing the dosage of the E. coli genes encoding polyphosphate kinase (ppk), acetate kinase (ackA), and the phosphate-inducible transport system (pstS, pstC, pstA, and pstB). Acetate kinase was employed as an ATP regeneration system for polyphosphate synthesis. Recombinant strains, which contained either pBC29 (carrying ppk) or pEP02.2 (pst operon), removed approximately two- and threefold, respectively, more Pi from minimal medium than did the control strain. The highest rates of Pii removal were obtained by strain MV1184 containing pEP03 (ppk and ackA). However, unlike the control strain, MV1184 (pEP03) released Pi to the medium after growth had stopped. Drastic changes in growth and Pi uptake were observed when pBC29 (ppk) and pEP02.2 (pst operon) were introduced simultaneously into MV1184. Even though growth of this recombinant was severely limited in minimal medium, the recombinant could remove approximately threefold more Pi than the control strain. Consequently, the phosphorus content of this recombinant reached a maximum of approximately 16% on a dry weight basis (49% as phosphate).

Alteration of the basement membrane in human thyroid diseases: an immunohistochemical study of type IV collagen, laminin and heparan sulphate proteoglycan

Basement membrane (BM) alteration in thyroid diseases was examined by immunohistochemistry using antibodies for the three major BM proteins: type IV collagen, laminin and heparan sulphate proteoglycan. Linear epithelial BMs surrounding follicles accompanied by vascular BMs forming loops, similar to those seen in the normal thyroid, were observed in Graves' disease and adenomatous goitre. Hashimoto's thyroiditis showed scant epithelial BMs as a result of follicle destruction. In follicular adenomas, development of epithelial BMs seemed to be related to follicle formation; well-developed epithelial BMs were frequently seen in normo- or large-follicular type, whereas trabecular or solid types revealed scant or poorly developed epithelial BMs. Lumpy accumulation of BM proteins was detected in hyalinizing trabecular adenomas. Papillary carcinomas revealed two different types of papillae; one type contained both epithelial and vascular BMs, and the other had only vascular BMs. Epithelial BMs in invasive areas of papillary carcinoma were distributed in an irregular, interrupted manner, and were completely absent in many foci. Anaplastic carcinomas showed scant or a total loss of epithelial BMs. These results suggest that alterations of BM in thyroid diseases clearly reflect their architectural variations, presumably in connection with their function and/or biological behaviour.

Birefringent (calcium oxalate) crystals in thyroid diseases. A clinicopathological study with possible implications for differential diagnosis

To elucidate the nature and significance of calcium oxalate crystals in the pathologic thyroid, we used polarized light microscopy to review 357 thyroid lesions. Under polarized light, calcium oxalate crystals had brilliant birefringence, and they were invariably identified within the colloid of follicles. The highest prevalence of crystals (87.9%) was in nodular goiters; they were also found in 60.0% of follicular adenomas and 33.3% of follicular carcinomas. The prevalence of crystals in papillary carcinomas was very low (5.4%). Therefore, the overall prevalence was 69.4% in benign nodules and 7.6% in malignant nodules. A heavy deposit of crystals was seen only in benign nodules except for one case of follicular carcinoma. Graves' disease, focal thyroiditis, and subacute thyroiditis showed low prevalence: 25.0, 46.9, and 40.0%, respectively. In cases of toxic nodules, the crystals were sparsely identified within nodules, but abundantly observed in surrounding inactive tissues. Immunohistochemistry for thyroid hormones confirmed that the crystals tended to appear in inactive follicles. On tissue x-ray film, the crystals appeared as microcalcifications. As a result of these findings, we suggest that examinations of crystals are likely to be useful in the differential diagnosis of thyroid diseases and in possible estimations of the functional state of lesions.

Clinical and pathologic properties of small differentiated carcinomas of the thyroid gland

Ninety-one small differentiated thyroid carcinomas less than 10 mm in size treated during the last 33 years were subjected to clinical study. In 44 of the 91 cases, tumor was found incidentally at surgery, while in the remaining 47 a thyroid mass was palpable before operation. A preoperative diagnosis of carcinoma could not be made in nodules less than 5 mm in size. Ultrasonographic examination is now extending the limits of exact diagnosis. Metastasis was found in 16 of 33 patients who had lymph nodes dissected. Metastatic lymph nodes were distributed in the same sites as those with thyroid carcinomas larger than 10 mm. Pathologic examination was carried out in 108 small carcinomas including cases from an affiliated hospital. Histologically, all of them were papillary or follicular carcinomas. The growth pattern of the tumors was divided into 5 groups: 23 were nonencapsulated sclerosing type, 29 encapsulated type without capsule invasion, 48 encapsulated type with capsule invasion, 4 the infiltrative type, and 4 the round type. Lymph node metastasis and intraglandular dissemination were found most frequently in the infiltrative type, followed by the encapsulated type with invasion. The results suggest the necessity of lymph node dissection and lobectomy for patients with these histological types of small carcinomas who had only local removal of the tumor.