Efficient lipase-catalyzed preparation of long-chain fatty acid esters of bile acids: biological activity and synthetic application of the products

A highly regioselective (3-position) and efficient (quantitative yield) acylation of bile acids catalyzed by immobilized Candida antarctica lipase was established. Methyl cholate derivatives acylated with long-chain fatty acids (C12-C16) showed an inhibitory effect on the growth of some strains of Gram-positive and -negative bacteria (27-400 micrograms/ml). The anti-bacterial activity was slightly weaker than has been observed for methyl cholate, while the increased lipophilicity and lower melting points of the present derivatives are well suited for a potential germicide which would be safe and be topically applied. This enzyme-catalyzed transesterification is also demonstrated as an expeditious route to ursodeoxycholic acid, in respect of the regioselective introduction of acyl protecting groups on the hydroxyl groups of the intermediates. 7-Ketolithocholic acid, a known direct precursor of ursodeoxycholic acid, was obtained from cholic acid via chenodeoxycholic acid in a 46% yield and 9 steps.

The first reported case of intestinal spirochaetosis in Japan

A 65-year-old Japanese male consulted Ozuchi Prefectural Hospital (Iwate, Japan) on 19 January 1994 complaining of weight loss. Cecal mucosal biopsy material, which was stained with hematoxylin-eosin revealed a thick, basophilic fuzzy fringe covering the surface epithelium. Transmission and scanning electron microscopy observations demonstrated the presence of slightly wavy spirochaetes with tapered ends, which were attached to the surface epithelium of the colonic mucosa via one of these ends. The patient did not display any clinical symptoms of inflammatory bowel disease, and laboratory tests eliminated an immunodeficiency condition. Thus, in the present case, the intestinal spirochaetes appear to be harmless commensals. This paper presents the first reported case of intestinal spirochaetosis in Japan.

Age distribution of the incidence of contact sensitivity to standard allergens

The incidence of contact sensitivity to standard allergens present in the daily environment, such as chromium ion, cobalt, nickel and formaldehyde, is found to decrease in the fourth decade. It strongly suggests the presence of some immunoregulation in human beings, because sensitivity to these allergens should be equal in any decade.

Similarity and variation in gene expression among human cerebral cortical subregions revealed by DNA macroarrays: technical consideration of RNA expression profiling from postmortem samples

The functional regionality of the human cerebral cortex suggests that a set of genes might be activated in each subregion of the neocortex to support its specific functions. To test this hypothesis, we employed the DNA array technique to compare the mRNA expression profiles of three neocortical subregions of the human brain: prefrontal cortex (Area 46), motor cortex (Area 4) and visual cortex (Area 17). The macroarray analysis on high quality mRNA from postmortem brains revealed that the expression profiles of the different cortical areas are almost similar: only six out of 1088 known genes exhibited significant differences (>2-fold) in their expression. RT-PCR studies with an increased number of samples confirmed that expression of only two genes, annexin II and early growth response protein 1, varied by 2-fold among the regions, whereas expression of the others showed large inter-individual difference. These results suggest that the whole neocortex of humans is more homogeneous than we expected at the level of gross gene expression profiles. In parallel, sensitivity and accuracy of radioisotope-based DNA macroarrays and fluorescence-based DNA microarrays were tested.

Signal propagation from piriform cortex to the endopiriform nucleus in vitro revealed by optical imaging

Optical signals were recorded from the posterior piriform cortex slices of guinea pigs stained with a voltage-sensitive dye to analyse spatio-temporal spread of neural activity evoked by electrical stimulation of afferent fibers. After propagation of activity along layers II and III, an isolated island of activity appeared deep to the layer III and moved caudally. Histological inspection revealed that the area where the island appeared corresponded well to the endopiriform nucleus. The present results provided an evidence for one of the main outflows of olfactory information from the posterior piriform cortex.

Ruptured de novo intracranial aneurysms

OBJECTIVE

We describe the actual state of ruptured de novo intracranial aneurysms to contribute to a guideline of follow-up for the patients with treated intracranial aneurysm.

METHODS

The authors retrospectively investigated 12 cases drawn from 483 consecutive cases of aneurysmal subarachnoid hemorrhage at our institute over a period of 22 years, in which a previously undemonstrated (hence "de novo") intracranial saccular aneurysm formed and ruptured after successful treatment of a prior aneurysm.

FINDINGS

The 12 cases constitute 2.5% of the 483 patients who left our hospital alive. Eleven cases were females and one was a male with a mean age of 55.7 years (range 29-75) at the first subarachnoid haemorrhage (SAH) and an interval between the first and the second rupture of 10.7 years (range: 2.6-23.8, standard deviation: 6.86, 95% confidence interval: 6.39-15.1). Four cases did not have risk factors such as hypertension, family history, smoking, multiple aneurysms, and moyamoya disease. None of these ruptured de novo aneurysms was at the same location as the original lesion. One-third (4 cases) of the de novo lesions in our series were found on the opposite side to each prior lesion.

INTERPRETATION

For not only young but also elder patients with a treated aneurysm (from the fifth decade to the sixth), especially for women, late angiography or alternative modalities of less-invasive examination should be considered. To detect de novo intracranial aneurysms before rupture, the search for a de novo aneurysm should be performed within 6.39 years after a previous examination that shows an aneurysm to be nonexistent, in view of the 95% confidence interval of the mean time to de novo aneurysmal rupture (6.39-15.1 years). If applied this survey, 75% (8 cases of 12 cases) of our de novo aneurysms would be detected before rupture.

Superconductivity in entirely end-bonded multiwalled carbon nanotubes

We report that entirely end-bonded multiwalled carbon nanotubes (MWNTs) can exhibit superconductivity with a transition temperature (T(c)) as high as 12 K, which is approximately 30 times greater than T(c) reported for ropes of single-walled nanotubes. We find that the emergence of this superconductivity is highly sensitive to the junction structures of the Au electrode/MWNTs. This reveals that only MWNTs with optimal numbers of electrically activated shells, which are realized by end bonding, can allow superconductivity due to intershell effects.

Mismatch repair deficiency leads to a unique mode of colorectal tumorigenesis characterized by intratumoral heterogeneity

In order to determine the effects of mismatch repair (MMR) deficiencies in sporadic colorectal carcinomas, 45 such cancers were examined using a sensitive method called crypt isolation technique. Loss of heterozygosity (LOH) in the MSH2 or MLH1 gene was more frequently observed in replication error (RER) (+) carcinomas than in RER (-) carcinomas, which implied that loss of one normal allele could partly affect repair capacity. MSH2 gene defects at both alleles were observed in two carcinomas, which showed severe repair deficiencies. Interestingly, unlike the situation observed in the p53 gene, the MSH2 and MLH1 genes did not show complete LOH. Novel crypt isolation-based subpopulation (CISP) analysis demonstrated that at least two distinct carcinoma subpopulations existed in most carcinomas that showed incomplete LOH; one with and one without LOH. In one carcinoma that had germline mutation and somatic incomplete LOH of the MSH2 gene, the mutator phenotype was only observed in populations affected in both alleles. Thus, the MSH2 gene appears to possess the two hits mechanism of tumor suppressor genes. However, unlike the tumor suppressor genes, MMR gene defects lead to a unique mode of colorectal tumorigenesis characterized by intratumoral heterogeneity.

Allelic losses of 17p, 5q, and 18q loci in diploid and aneuploid populations of multiploid colorectal carcinomas

17p, 5q, and 18q allelic losses are involved in the pathogenesis and progression of colorectal carcinoma, and DNA aneuploidy in this type of cancer is thought to result from alterations of these chromosomal loci. However, genetic differences between diploid and aneuploid populations of multiploid carcinoma, defined as the coexistence of diploid and aneuploid populations in the same area, remain unclear. The differences in 17p, 5q, and 18q allelic losses between the diploid and aneuploid populations in 24 sporadic DNA multiploid colorectal carcinomas were analyzed by use of crypt isolation coupled with DNA cytometric sorting and polymerase chain reaction assay. 17p Allelic loss was observed in 7 of 22 diploid populations excluding 1 case of microsatellite instability but was found in 21 of 23 aneuploid populations. Although 5q allelic loss was detected in only 3 of 22 diploid populations, 13 of 22 aneuploid populations had 5q allelic loss. Losses of the 18q allele were frequently found in aneuploid populations (15 of 20), although no 18q allelic loss was detected in corresponding diploid populations. 17p Allelic losses may play an important role in the progression from a diploid status to an aneuploid status in a specific subset of colorectal cancer. However, 18q or 5q allelic losses do not appear to precede nor to facilitate the aneuploid clonal divergence of cancer cells. Multiploidy is a useful model to study genetic alterations between diploid and aneuploid populations.

Multimodal cross-talk of olfactory and gustatory information in the endopiriform nucleus in rats

The endopiriform nucleus (EPN) is a large group of multipolar cells located in the depth of the piriform cortex (PC). Although many studies have suggested that the EPN plays a role in temporal lobe epilepsy, the normal function of the EPN remains to be elucidated. By using optical imaging of coronal brain slice preparations with voltage-sensitive dye, we found signal propagation from the PC or gustatory cortex (GC) to the EPN in normal medium. In our previous research, we failed to elicit a reliable signal reproducibly in the EPN by single stimulation either to the PC or GC. In our current research, we found that a double-pulse stimulation to either the PC or GC (interpulse interval: 20-100 ms) induced robust signal propagation to the EPN through excitation in the agranular division of the insular cortex (AI), with further extension to the claustrum. Finally, double site paired-pulse stimulation to the PC and GC also evoked excitation in the AI, claustrum, and EPN. These results suggest that the EPN has dual roles: 1) further processing of modality-specific olfactory and gustatory information from the PC and GC, respectively and 2) synergistic integration of PC-derived olfactory information and GC-derived gustatory information.

Improvement of tardive dyskinesia and dystonia associated with aripiprazole following a switch to quetiapine: case report and review of the literature

WHAT IS KNOWN AND OBJECTIVE

Aripiprazole has a low risk of extrapyramidal symptoms. Switching to aripiprazole has been reported to improve tardive dyskinesia caused by other medications. The authors report a case and review previous reports of dystonia and dyskinesia associated with aripiprazole.

CASE SUMMARY

We present a case of a 22-year-old man with schizophrenia who experienced dyskinesia and dystonia associated with aripiprazole. Switching from olanzapine to aripiprazole resulted in worsening dyskinesia and new onset of dystonia. The patient's dyskinesia and dystonia improved after switching from aripiprazole to quetiapine therapy.

WHAT IS NEW AND CONCLUSION

There were several previous case reports on dyskinesia and dystonia associated with aripiprazole medication. The risk factors for tardive dyskinesia include older age and female sex. However, our case was a male patient who was younger compared with the previous cases and so should have been less at risk for dyskinesia in comparison with the previous cases. The effects of aripiprazole can include tardive movement disorders. Dyskinesia, dystonia and psychotic symptoms were improved with relatively small dose of quetiapine in this case. Whether some second-generation antipsychotics are more effective than others in the treatment of tardive dyskinesia remains unclear.

Frequent allelic imbalance at the ATM locus in DNA multiploid colorectal carcinomas

DNA multiploidy may involve specific DNA ploidy states with respect to genetic alterations such as oncogenes, tumor suppressor gene mutation and microsatellite instability. To clarify the role of DNA multiploidy in colorectal cancer, we analysed allelic imbalance involving the ATM gene, localized to chromosome 11q22-23 and thought to be involved in genetic stability, in a series of multiploid colorectal carcinomas. In addition, p53 gene mutation (exons 5-8) and allelic imbalance at 11q24 loci distal to the ATM locus were also examined. The crypt isolation technique coupled with DNA cytometric sorting and polymerase chain reaction assay using 10 microsatellite markers tightly linked to the ATM gene were used to study ATM allelic imbalance in 55 colorectal carcinomas (15 diploid, 13 aneuploid, 27 multiploid). While allelic imbalance at the ATM locus was rarely observed in diploid and aneuploid carcinomas, multiploid carcinomas exhibited a high frequency of ATM allelic imbalance. In multiploid carcinoma samples, diploid subpopulations showed a smaller range of allelic imbalance at the loci tested compared to aneuploid subpopulations that demonstrated allelic imbalance over a relatively large region. Also, the frequency of AI at 11q24 showed a similar tendency to that at the ATM locus for each DNA ploidy state. An association between p53 gene mutation and ATM allelic imbalance in multiploid carcinoma was also observed. Our results suggest that ATM allelic imbalance and p53 gene mutations occur during the progression from diploid to aneuploid cell populations in multiploid colorectal carcinomas.

Allergic contact urticaria caused by raw prawns and shrimps: three cases

Contact urticaria from raw prawns and shrimps was suspected in three housewives with hand eczema who visited our clinic. A practice skin test in which patients stripped the shells from raw prawns and shrimps was positive, but an intradermal skin test with an allergen extracted from a mixture of prawns and shrimps was negative. Results of skin tests with fresh extracts of raw prawns and shrimps were positive. The RAST with a paper disc method with use of a raw prawn and shrimp as antigens was also positive in these three patients. It is evident from the results obtained that some common substances causing a local urticaria exist in raw prawns and shrimps.

Optical resolution of racemic citronellol via a double coupling system in an interface bioreactor

A double coupling system consisting of acetyl coenzyme A [acetyl-CoA] formation via the metabolism of glucose and the subsequent acetylation of a primary alcohol by acetyl-CoA with the aid of alcohol acetyltransferase [AATFase], was applied for the optical resolution of racemic citronellol. Pichia kluyveri IFO 1165 was superior for the optical resolution of racemic citronellol and provided (S)-citronellyl acetate and (R)-citronellol with high enantioselectivity and yield. The strain also exhibited excellent resistance to high concentrations of citronellol, i.e., it could maintain metabolism and enantioselective acetylation even in the presence of 30% citronellol. The coupling system using P. kluyveri IFO 1165 was applied to two new types of interface bioreactors, tentatively referred to as bead-packed and multistory interface bioreactors. Using the latter bioreactor, (S)-citronellyl acetate and (R)-citronellol were produced in large amounts at high enantioselectivity and yield.

Effect of risperidone metabolism and P-glycoprotein gene polymorphism on QT interval in patients with schizophrenia

Risperidone (RIS) is a frequently used efficacious psychotropic drug. However, it prolongs the QTc interval and may cause fatal arrhythmia. Little is known on the determinants of this RIS side effect. RIS is metabolized by CYP2D6, and is subject to drug efflux by P-glycoprotein (P-gp) encoded by the ATP-binding cassette subfamily B member 1 (ABCB1) gene. P-gp removes both RIS and its metabolite 9-OH-RIS from cardiac tissue. To investigate the effect of RIS metabolism and ABCB1 gene polymorphisms on QTc, steady-state plasma RIS and 9-OH-RIS levels, and QTc were measured. CYP2D6, ABCB1 C3435T and G2677T/A genotypes were determined in 66 schizophrenia patients on RIS. QTc was significantly longer in patients with ABCB1 3435CT+3435 TT than in those with 3435CC (P=0.006). ABCB1 G2677T/A genotype did not affect QTc. Multiple regression analysis showed that C/T or T/T genotypes at the ABCB1 C3435T locus, lower weight, and older age prolonged QTc. In summary, the T allele of the ABCB1 C3435T genotype should be considered in future diagnostic development efforts for RIS-associated QT.

CMP-KDO synthetase: overproduction and application to the synthesis of CMP-KDO and analogs

CTP:CMP-3-deoxy-manno-octulosonate cytidylyltransferase (CMP-KDO synthetase, EC 2.7.7.38) has been cloned and overexpressed in Escherichia coli. The structure gene was amplified from the total DNA of E. coli K-235 through the primer-directed polymerase chain reaction. The gene was then cloned into lambda ZAP vector at the EcoRI and XbaI restriction sites and overexpressed in E. coli Sure strain at a level approximately 400 times as much as that produced in the host strain. Application of the enzyme to the synthesis of cytidine 5'-monophospho-3-deoxy-D-manno-2-octulosonic acid (CMP-KDO) and analogs was studied. Of several KDO analogs tested, 5-fluoro-2-keto-3,5-dideoxyoctulosonic acid (5-FKDO) was found to be a good substrate of the enzyme, and the product (CMP-5-FKDO) was prepared and characterized, representing the first stable CMP-KDO analog prepared enzymatically to date. The natural enzyme product, CMP-KDO, was however quite unstable (t1/2 = 19 min, in 50 mM MgCl2, 0.2 M Tris buffer, pH 9.0). A mechanism for the decomposition of CMP-KDO involving the hydrogen bonding interactions between the OH groups of C-5 and C-7 (and/or C-8) and the phosphate oxygens was proposed.

Use of crypt isolation to determine loss of heterozygosity of multiple tumor suppressor genes in colorectal carcinoma

Analysis of loss of heterozygosity (LOH) is very important in the study of tumor suppressor genes. However, accurate LOH analysis of tumor suppressor genes is difficult because of dilution by contaminating non-tumor DNA. Thus, enrichment of tumor DNA is required to accurately determine LOH of the tumor. We developed a new application of the fluorescent polymerase chain reaction by coupling it with crypt isolation to accurately assess the incidence of LOH of tumor suppressor genes in 45 colorectal carcinomas. LOH was observed at p53 in 26 of 37 tumors (70.3%), at APC in 13 of 35 (37.1%), at DCC in 16 of 25 (64.0%), at NF-2 in 5 of 23 (21.7%), and at nm23 H-1 in 7 of 30 (23.3%). We could clearly determine LOH of these genes because the crypt isolation technique was used. Although the incidence of LOH at each of these loci, as determined by using this technique, was similar to that obtained in previous studies using conventional methods, this method provides a simpler, more accurate way to assess LOH. In addition, the morphology of the samples can be analyzed before genetic analysis.

Heterogeneity in the nuclear DNA content of cells in carcinomas of the biliary tract and pancreas

BACKGROUND

The authors investigated the frequency of aneuploidy and heterogeneity in DNA ploidy within one tumor by multiple sampling.

METHODS

Using flow cytometry, the authors measured the nuclear DNA content of cells in fresh surgical specimens from 24 patients with carcinoma of the extrahepatic bile duct, 8 patients with carcinoma of the gallbladder, 5 patients with carcinoma of ampulla of Vater, and 14 patients with carcinoma of the pancreas.

RESULTS

The frequency of aneuploidy was 91.7%, 87.5%, 80.0%, and 85.7% in carcinoma of the extrahepatic bile duct, gallbladder, ampulla of Vater, and pancreas, respectively. The incidence of heterogeneity in DNA ploidy within a tumor was 79.2%, 87.5%, 80.0%, and 85.7% in carcinoma of the extrahepatic bile duct, gallbladder, ampulla of Vater, and pancreas, respectively. The DNA index ranged mostly from 1.0-2.0. Hypodiploid samples constituted 23.5% of the total, and only five (9.8%) had a DNA content above tetraploid. Many of the patients in which the DNA index was about 1.0 (including diploid cases) tended to be in the relatively early stages of the disease.

CONCLUSIONS

It is necessary to take several fresh samples from the same tumor to accurately measure the variations in nuclear DNA content. The authors suggest that three or four samples should be studied to determine aneuploidy and that DNA ploidy heterogeneity should be analyzed in five or six samples.

The vegetative micronucleus has a critical role in maintenance of cortical structure in Tetrahymena thermophila

The vegetative role of the germinal micronucleus of Tetrahymena thermophila was studied. Amicronucleate cells that had spontaneously arisen in star strains (very aged cones with defective micronuclei) were observed in B* as well as in A* and in C* and were found to lack the oral apparatus and to have disordered ciliary rows. To reduce uncertainty given the very small micronucleus and possible effects of aging factors, we induced amicronucleate cells in a young clone by treatment with the antitubulin drug, nocodazole, and observed their cortical structure and nuclei. Amicronucleate cells gradually lost their oral apparatus and then their ciliary rows became disordered, even without cell division, and they became crinkled cells. It can be concluded that the vegetative micronucleus appears to play a critical role in the maintenance of the cortical structure, especially of the oral apparatus.

A serotonergic discrimination favoring synaptic inputs that accompany robust spike firing in lateral amygdala neurons

The amygdala and serotonergic innervations thereunto are considered to cooperatively modulate affective behaviors. By whole-cell recording, the present study examined effects of serotonin (5-HT) on synaptic transmission in the rat basolateral amygdala (BLA) complex, which is the amygdalar entrance for sensory information. Application of 5-HT-attenuated excitatory postsynaptic currents at synapses from the lateral amygdala (LA) to the BLA proper, and also at synapses from putative thalamic afferents to LA principal neurons, both depending on 5-HT(2) receptors. This reduction of synaptic responses was confirmed in the BLA under current clamp. In the LA, by contrast, synaptic potentials were not reduced, but enhanced by 5-HT. With 5-HT bath-applied, a prolonged depolarization was induced in LA neurons by strong synaptic stimulation, which appears similar to a slow after-depolarization (sADP) induced by injecting depolarizing currents. Occurrence of such current-induced sADP was confirmed in LA neurons. Both the synaptically-activated prolonged depolarization and the current-induced sADPs depended on 5-HT(2) receptor activation and postsynaptic calcium increase, suggesting that the same postsynaptic intrinsic mechanisms are involved. Reduction of potassium currents was identified as a major ionic mechanism for this sADPs. We thus revealed that 5-HT usually reduces overall synaptic transmission in the whole BLA complex, but enables sADPs to occur, thereby increasing synaptic responsiveness of LA neurons in a positive feedback manner. With this duality of 5-HT actions in operation, a weak input to the BLA complex would be usually eliminated, but could be selected were it associated with sufficiently large depolarization.

Mandibular traction for relieving respiratory distress in the Pierre Robin Anomaly. A case report

A case of Pierre Robin Anomaly with severe, prolonged respiratory distress and feeding difficulties is presented. The respiratory distress is adequately relieved by mandibular forward traction. The procedure employing a mandibular suspension and elastic traction system is described. Feeding under the traction was successful, providing more effective self-control of the tongue. The authors recommend the mandibular traction device described here as a very simple life-saving approach to the problems in the Pierre Robin Anomaly.

Analysis of subclonal expansion of colorectal carcinomas by flow cytometry

DNA heterogeneity of colorectal carcinomas has been investigated by flow cytometry, most studies have focused on the clinical usefulness of DNA ploidy analysis. Since cancers consist of predominant subclones with proliferative advantage due to clonal expansion, we attempted to analyse the clonal expansion of colorectal carcinomas within a tumour by measuring DNA ploidy. The DNA ploidy and heterogeneity of multiple fresh samples obtained from 164 colorectal adenocarcinomas were analysed by flow cytometry. Each tumour was divided into an average of six specimens, which were analysed separately. For 146 of the tumours (89%) at least one DNA aneuploid population was found within the cancer tissue examined. DNA multiploidy was detected in 26 cases (17.8%) among the cancers with aneuploidy. Based on the DNA index (DI), hypertriploid aneuploidy (1.7<DI<1.8) was found most frequently in the aneuploid colorectal cancers examined. DNA ploidy heterogeneity was seen in 75 (51.4%) of the DNA aneuploid tumours. There were only 3 cases with more than three subclones including a diploid line. The present results indicate that colorectal carcinomas consist of a few dominant subclones and have a DNA content (hypertriploid aneuploid) that confers a proliferative advantage.