Detection of single-nucleotide mutations including substitutions and deletions by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) was applied to the detection of mutations involving single nucleotides. For detection of a single-nucleotide deletion, a normally 44 bp region of the L1CAM gene was amplified in a 50 microL solution, and measurement was carried out on the DNA sample after phenol extraction and ethanol precipitation. A molecular mass decrease of 300 Da corresponding to a single nucleotide was identified in the amplified product of patient DNA. For detection of a substitution, an amplified product from a 50 bp region of the human beta-globin gene was cleaved with restriction endonucleases HaeIII and Bsp12861. Measurement of a mixture of digested fragments, or restriction fragment mass mapping, clearly identified a heterozygous G/C mutation in the molecular ion signals for both sense and antisense single-stranded DNAs. The results indicate that MALTI-TOFMS is feasible for genetic diagnosis of point mutations.

An effective chemotherapy regimen for liver metastasis from retroperitoneal fibrosarcoma: report of a case

Retroperitoneal fibrosarcoma is a rare disease that has proven difficult to treat due to its high incidence of postoperative local recurrence. We recently experienced a patient in whom retroperitoneal fibrosarcoma was followed by liver metastasis without local recurrence. A 34-year-old woman who initially presented with right upper quadrant pain was found to have a retroperitoneal tumor by diagnostic imaging techniques. Extirpation of the tumor was performed and the histopathological diagnosis was fibrosarcoma. A solitary metastasis was detected in the lateral segment 1 year after this operation and a lateral segmentectomy was carried out; however, a short time later, multiple liver metastases were found. Initially, ethanol injections were given with little effect, following which CYVADIC chemotherapy, consisting of cyclophosphamide, vincristine, farmorubicin, and dacarbazine was administered. An excellent responsiveness without severe toxicity was achieved after five cycles, with a significant reduction in tumor size, being estimated as a complete response. Thus, we consider that this chemotherapy regimen could be a promising mode of treatment for liver metastasis from retroperitoneal fibrosarcoma without local recurrence.

Asymmetrical dimethylarginine, an endogenous nitric oxide synthase inhibitor, in experimental hypertension

NG,NG-dimethyl-L-arginine (ADMA) is an endogenously synthesized nitric oxide (NO) synthase inhibitor which has potent pressor/vasoconstrictor effects. Dimethylargininase metabolizes ADMA to L-citrulline and plays a key role in determining the in vivo levels of ADMA. To investigate the role of ADMA in the pathogenesis of hypertension, we measured 24-hour urinary excretion of ADMA (UADMA) and nitrate/nitrite (NOx) in Dahl salt-sensitive hypertensive rats and spontaneously hypertensive rats (SHR). In Dahl salt-resistant rats, high-salt diet (8% NaCl) did not increase blood pressure and increased urinary NOx (P < .01) without changes in UADMA compared with low-salt diet (0.3% NaCl). In contrast, in Dahl salt-sensitive rats, high-salt diet increased blood pressure (P < .01), did not change urinary NOx excretion, and increased UADMA (P < .01). There was a significant (r = .65, P < .01) correlation between UADMA and the level of blood pressure in Dahl salt-sensitive rats. Plasma levels of NOx and ADMA and renal dimethylargininase content were comparable among them. These results may suggest that in Dahl salt-resistant rats, blood pressure is kept constant during high-salt intake, possibly due to the compensatory increased production of NO, and that in Dahl salt-sensitive rats, high-salt intake increases the production of ADMA, attenuates the compensatory increases in NO, and increases blood pressure. These results also suggest that the systemic production of ADMA is not dependent on renal dimethylargininase. SHR had significantly greater urinary NOx excretion (P < .05) and smaller UADMA than Wistar-Kyoto rats (P < .05), and UADMA was inversely correlated with their mean arterial pressure (r =.64, P < .05). In conclusion. ADMA, independently of the renal dimethylargininase content, may play a role in the pathogenesis in Dahl salt-sensitive hypertensive rats but not in SHR.

Modification of ciliary beating in sea urchin larvae induced by neurotransmitters: beat-plane rotation and control of frequency fluctuation

The modification of ciliary beating by neurotransmitters in sea urchin larvae at the four-armed pluteus stage was analyzed in terms of the direction of beating and fluctuation in the beat period. Application of dopamine to Pseudocentrotus depressus causes the cilia to turn their beat plane but retain its characteristic planar feature up to the complete 'reversal' of the beat direction. This new type of response was termed the 'beat-plane turning response'. It was also found that neurotransmitters, especially dopamine and serotonin, can modify the length of the beating cycle in P. depressus and Hemicentrotus pulcherrimus. Dopamine decreased and serotonin increased the beat frequency averaged over the ciliated epithelium with the standard deviation from the mean increasing in the presence of dopamine and decreasing with serotonin. The beat-period fluctuation and its modification suggested by this observation was confirmed from measurements of the beating of individual cilia in the presence or absence of these neurotransmitters. Further analysis of the correlation between angular velocity and beat period indicates that variation in the beat period is not controlled by the same processes as those that modulate angular velocity. These findings in sea urchin larvae suggest that both the stability and the direction of ciliary beating is under nervous control.

Sympathetic outflow response to muscle during vestibular stimulation in humans

To observe the effects of caloric vestibular stimulation on muscle sympathetic nerve activity (MSNA) in humans, 14 healthy volunteers were monitored in a supine position by electrocardiogram (ECG), blood pressure (BP), electro-oculogram (EOG). MSNA was monitored by a double recording technique of microneurography from the bilateral tibial nerves. Caloric vestibular stimulation was loaded by injecting 50 ml 44 degrees C warm water and 50 ml 10 degrees C cold water alternately into the external meatus for 1 min. Nystagmus was evoked in all cases by cold stimulation and in some cases by hot stimulation. The nystagmus evoked by cold stimulation was more intense than that by hot stimulation. MSNA was enhanced by either cold or hot stimulation; however, the enhancement mode differed between cold and hot stimulation. Cold stimulation evoked two peaks of MSNA while hot stimulation elicited only one peak. The first peak (404.5 +/- 115.4% with control value set at 100%, mean +/- SE) was estimated to be caused by cold stimulation on the skin of the external meatus while the second peak (379.2 +/- 65.3%) seemed to be the result of vestibular stimulation. With hot stimulation, the response peak of MSNA was 243.3 +/- 28.1%. In general, MSNA was enhanced after vestibular stimulation with MSNA increases was proportional to the stimulated level of the vestibular system.

[Xanthine oxidase deficiency (hereditary xanthinuria), molybdenum cofactor deficiency]

Hereditary xanthinuria is a rare autosomal recessive disorder, with xanthine oxidase deficiency. Patients often display renal symptoms because they excrete a large amounts of xanthine in urine. An high-fluid-intake, alow-purine-food, and alkalinization of urine are effective in the patients. Molybdenum cofactor is essential for xanthine oxidase, sulfite oxidase and aldehyde oxidase. Patients with molybdenum cofactor deficiency display severe neurological symptoms, such as severe convulsions. The patients increase urinary excretions of xanthine and sulfite. Treatments are ineffective for neurological symptoms.

[Xanthine oxidase (xanthine dehydrogenase)]

Xanthine oxidase (xanthine dehydrogenase) is composed of two identical subunits of approximately 150,000 daltons. Each subunit contains four oxdation-reduction active cofactors/monomers. In vivo, the enzyme exists mostly as the dehydrogenase type (the NAD-dependent type). The cDNA has been cloned from human liver, and the amino acid sequence has been determined. As xanthine oxidase seems to produce superoxide in postischemic reperfusion, the relation between the superoxide and postischemic tissue injury has been discussed. It has also been reported that inhibition of xanthine oxidase by allopurinol may cause severe 6-mercaptopurine toxicity.

[Left ventricular lesions in arrhythmogenic right ventricular dysplasia and 12-lead electrocardiographic findings]

Left ventricular lesions in arrhythmogenic right ventricular dysplasia have not been well described, and the relationship between the left ventricular lesions and the 12-lead electrocardiographic findings has not been analyzed. This study examined whether the presence of left ventricular lesions and the extent of right ventricular lesions due to arrhythmogenic right ventricular dysplasia are predictable by 12-lead electrocardiographic findings. The 12-lead electrocardiograms during sinus rhythm and left and right ventriculography were studied in 29 patients (27 males and 2 females, mean age 42.6 +/- 15.5 years) diagnosed by the current criteria for this disease. After evaluation, patients were divided into two groups: those with normal left ventricles (normal group) and those with left ventricular wall motion abnormalities (abnormal group). Seventeen of the 29 patients (59%) were classified into the abnormal group. Left ventricular wall motion abnormalities were located in the posterolateral (4 patients), apical (1), and posterolateral and apical regions (12). QS patterns of abnormal Q waves in lead I, aVL or V5, V6 rS patterns (R/S ratio < 1) in leads I and V6, and/or R or Rs patterns (R/S ratio > 1) in lead V1 were observed in all patients in the abnormal group, but in none in the normal group. There was a positive correlation between the right ventricular end-diastolic volume index and the number of precordial negative T waves (r = 0.746, p < 0.0001), and the time from onset of the QRS to the terminal portion of the epsilon wave in lead V1 (r = 0.627, p < 0.001). The correlation coefficients showed no significant differences between the groups. A left ventricular lesion associated with arrhythmogenic right ventricular dysplasia was not unusual (59%), and our study suggests that the posterolateral and apical regions are the most frequent sites. The presence of these lesions were predictable by the QRS abnormalities. Moreover, regardless of the presence of such a lesion, the extent of the right ventricular lesion is also predictable by the 12-lead electrocardiographic findings.

Deletion mapping on chromosome 10q25-q26 in human endometrial cancer

To understand genetic events which play a role in the development and/or progression of human endometrial cancer, we studied allelotypes on all autosomal chromosomes, as well as chromosome X, with 42 microsatellite markers and 56 endometrial cancers. The most frequent loss of heterozygosity (LOH) was observed on the long arm of chromosome 10 (14 of 30, 47%), which was commonly detected in grade 1 cancer. We constructed a detailed deletion map and defined two commonly deleted regions in 10q25-q26; one was the 8 cM region between D10S209 and D10S216, the other was the 12 cM region between D10S217 and D10S590. Replication errors at two or more loci were observed in 24 of 56 tumours (43%), suggesting that disruption of the DNA mismatch repair system also plays an important role in the course of endometrial carcinogenesis.

Possible prediction of adverse reactions to pyrimidine chemotherapy from urinary pyrimidine levels and a case of asymptomatic adult dihydropyrimidinuria

Deficiency of dihydropyrimidine dehydrogenase or dihydropyrimidinase, enzymes that catalyze the breakdown of pyrimidine chemotherapy agents such as 5-fluorouracil, may cause serious adverse reactions to these agents. We attempted to establish the reference range for urinary pyrimidines in adults to detect individuals with abnormal pyrimidine metabolism. We analyzed urinary pyrimidine levels in 1133 adults to establish a reference range for persons ages 20 years or older. Urinary dihydrouracil and uracil levels were determined by high-performance liquid chromatography with column switching. The reference range obtained was found to be 0-59.3 micromol/g creatinine for dihydrouracil and 0-129.8 micromol/g creatinine for uracil. In addition, an asymptomatic man with suspected dihydropyrimidinase deficiency was detected on the basis of dihydropyrimidinuria. Although only three cases of this disease have been found worldwide, including one infant reported previously by our group, it may not be so rare as has been thought. In this man, a 10 mg/kg oral uracil loading test yielded a peak blood dihydrouracil level of 192.1 micromol/liter and a peak uracil level of 67.8 micromol/liter. Eight h after loading, the uracil level was still 11.1 micromol/liter, about 17 times that in healthy subjects. Additional research on dihydropyrimininase deficiency may help to prevent adverse reactions to pyrimidine chemotherapy agents in susceptible individuals.

Vacuolar function in the phosphate homeostasis of the yeast Saccharomyces cerevisiae

We studied physiological roles of the yeast vacuole in the phosphate metabolism using 31P-in vivo nuclear magnetic resonance (NMR) spectroscopy. Under phosphate starvation wild-type yeast cells continued to grow for two to three generations, implying that wild-type cells contain large phosphate pool to sustain the growth. During the first four hours under the phosphate starved condition, the cytosolic phosphate level was maintained almost constant, while the vacuolar pool of phosphate decreased significantly. 31P-NMR spectroscopy on the intact cells and perchloric acid (PCA) extracts showed that drastic decrease of polyphosphate took place during this phase. In contrast, delta slp1 cells, which were defective in the vacuolar compartment, thus lacked polyphosphate, ceased their growth immediately when they faced to phosphate starvation. Taken together, we conclude that vacuolar polyphosphate provides an active pool for phosphate and is mobilized to cytosol during phosphate starvation and sustained cell growth for a couple rounds of cell cycle.

A novel mutation in L1CAM gene in a Japanese patient with X-linked hydrocephalus

L1CAM is a member of the immunoglobulin gene superfamily of neural adhesion molecule. Abnormality of the L1CAM gene is associated with X-linked recessive form of congenital hydrocephalus (HSAS; hydrocephalus due to congenital stenosis of aqueduct of Sylvius) and some allelic disorders. Four new patients with congenital hydrocephalus consistent with the X-linked type were described. One of them had a novel mutation in the L1CAM gene.

Method for quantitative estimation of position perception using a joystick during linear movement

We designed a method for quantitatively estimating self-motion perceptions during passive body movement on a sled. The subjects were instructed to tilt a joystick in proportion to perceived displacement from a giving starting position during linear movement with varying displacements of 4 m, 10 m and 16 m induced by constant acceleration of 0.02 g, 0.05 g and 0.08 g along the antero-posterior axis. With this method, we could monitor not only subjective position perceptions but also response latencies for the beginning (RLbgn) and end (RLend) of the linear movement. Perceived body position fitted Stevens' power law, where R=kSn (R is output of the joystick, k is a constant, S is the displacement from the linear movement and n is an exponent). RLbgn decreased as linear acceleration increased. We conclude that this method is useful in analyzing the features and sensitivities of self-motion perceptions during movement.

A tumor preventive effect of dietary restriction is antagonized by a high housing temperature through deprivation of torpor

Energy restriction (ER) has proven to be the only effective means of retarding aging in mice. The mechanisms of multiplicity of effects of ER on aging remain, however, fragmentary. ER induces daily torpor, the induction of which is reduced by increasing the ambient temperature to 30 degrees C. The effects of preventing hypothermia in ER animals were studied in terms of the expected consequences of ER on survival, disease pattern and a number of physiological parameters in autoimmune prone MRL/lpr mice and lymphoma prone C57BL, 6 mice. The results demonstrate that torpor plays a crucial role in the prevention of lymphoma development but does not have an affect on other aspects of ER, such as prevention of autoimmune diseases.

Relationship between pharmacokinetics of unchanged cisplatin and nephrotoxicity after intravenous infusions of cisplatin to cancer patients

PURPOSE

The relationships between pharmacokinetic parameters of unchanged cisplatin (CDDP) and several markers for nephrotoxicity after CDDP infusion (80 mg/m2) over 2 and 4 h were quantitated in patients with various cancers (lung, stomach and colon cancers and mediastinal tumor).

METHODS

Plasma and urinary levels of unchanged CDDP were measured using a specific high-performance liquid chromatography method. Pharmacokinetic parameters were calculated according to the model-independent method. The nephrotoxicity markers, blood urea nitrogen (BUN), serum creatinine (SCr), plasma and urinary beta2-microglobulin (BMGp and BMGu), urinary N-acetyl-beta-D-glucosaminidase (NAG) and creatinine clearance (CCR) were monitored for 30 days following CDDP administration.

RESULTS

The maximum plasma concentration (Cmax), maximum urinary excretion rate (dAe/dt(max)), area under the plasma concentration-time curve from time zero to infinity (AUC), cumulative amount excreted in urine from time zero to infinity (Ae), total clearance (Clt), renal clearance (Clr) and plasma half-life (t1/2) of unchanged CDDP were not significantly different between the 2-h and 4-h infusion schedules. The values of the nephrotoxicity markers changed significantly following CDDP administration, suggesting that CDDP chemotherapy (80 mg/m2) caused nephrotoxicity. The Cmax of unchanged CDDP was the most informative pharmacokinetic parameter for nephrotoxicity. Cmax was related to maximum BUN, maximum SCr and minimum CCR levels in 27 CDDP treatments according to an exponential model.

CONCLUSION

In order to attain more effective CDDP chemotherapy with minimum nephrotoxicity, the present pharmacokinetic and pharmacodynamic studies suggest that the Cmax or steady-state plasma level of unchanged CDDP should be maintained between 1.5 and 2 microg/ml in a standard continuous infusion schedule over 2 h and 4 h.

Gastric attaching and effacing Escherichia coli lesions in a puppy with naturally occurring enteric colibacillosis and concurrent canine distemper virus infection

A puppy suffering from chronic diarrhea was humanely killed at 90 days of age. Numerous Gram-negative bacilli were found adhering to the surface of as well as within epithelial cells from the stomach to the colon. Canine distemper virus inclusions were in the epithelial cytoplasm of the esophageal, gastric, and intestinal mucosa. Typical attaching and effacing ultrastructural lesions were in the stomach, and some bacilli were in the cytoplasm of the epithelial cells. Escherichia coli, isolated from the contents of the small intestine, belonged to serotype 0118: NM and were negative for plasmid-encoded EPEC adherence factor (EAF) and positive for the E. coli attaching effacing (eae) gene. Immunohistologically, bacilli attached to the epithelium from the stomach to the colon were positive for antisera against E. coli 0118. E. coli 0118: NM inoculated into human tissue culture cells (HEp-2 cells) were attached to the surface of the cells and within the cytoplasm. This is the first report of attaching and effacing E. coli (AEEC) infection in the stomach of the dog.

Genomic heterogeneity in bladder cancer as detected by fluorescence in situ hybridization

OBJECTIVE

To investigate the relationship between genomic heterogeneity and tumour grade, stage and DNA content in 30 transitional cell carcinomas (TCCs) of the urinary bladder.

MATERIALS AND METHODS

Tissue specimens from 30 patients (25 men and five women) with newly diagnosed TCC of the urinary bladder were examined for genomic heterogeneity using fluorescence in situ hybridization (FISH) with chromosome-specific DNA probes; the copy number of pericentromeric sequences on chromosomes 7, 9 and 17 was detected within interphase nuclei in contact preparations from the tumour specimens.

RESULTS

The aneusomy of chromosomes 7, 9 and 17 was significantly higher in aneuploid than in diploid tumours (P < 0.001). Tumour grade and stage were strongly associated with aneusomy for chromosome 17 (P < 0.01, P < 0.001, respectively). The aneusomy of chromosomes 7 and 9 were significantly correlated with increasing tumour stage (P < 0.001), but not with tumour grade.

CONCLUSION

These results suggest that the measurement of aneusomy using FISH, especially for chromosome 17, in bladder cancer may offer a new objective and quantitative assay of the biological potential of individual tumours.

Structural and functional analyses of APG5, a gene involved in autophagy in yeast

The APG5 gene of Saccharomyces cerevisiae was cloned from a yeast genomic library by complementation of autophagy defective phenotype of apg5-1 mutant. Structural analysis of the obtained genomic fragment showed that the APG5 gene encodes a novel hydrophilic protein of 294 amino-acid residues without apparent structural similarities to other proteins in the database. To examine its function, a null allele for APG5 (delta apg5) was constructed and introduced into yeast. delta apg5 cells germinated and grew normally in nutrient-rich condition, however, their viability reduced significantly upon the nutrient starvation. They were also shown to be defective in autophagy: they could not sequester autophagic bodies in the vacuole under nitrogen-starvation conditions. These phenotypes are identical to those found in the apg5-1 mutant. The lack of apparent phenotype in rich medium suggests that APG5 function is required only under nutrient starvation condition, however, Northern blot analysis showed that its expression levels remained unchanged after nutrient depletion.

Pathomorphological study of Kupffer cells in hepatocellular carcinoma and hyperplastic nodular lesions in the liver

A pathomorphological study was conducted to clarify the localization of Kupffer cells in hepatocellular carcinoma (HCC) tissues and such hyperplastic nodular lesions as adenomatous hyperplasia (AH) and focal nodular hyperplasia (FNH). Materials were surgical specimens of 50 HCCs, 7 AHs, and 13 FNHs. These tissues were immunohistochemically stained with an anti-human macrophage antibody (anti-CD68 antibody). Among CD68-positive cells, short spindle-shaped cells were considered as Kupffer cells, and Kupffer cell numbers in tumor lesions and surrounding liver tissues of each specimen were comparatively examined. As a result, the number of Kupffer cells in well-differentiated HCC tissues less than 1 cm in diameter was 27.8 +/- 3.3 (mean +/- SE/025 mm2); in noncancerous tissues, it was 302 +/- 3.2, showing no statistically significant differences. The number of Kupffer cells in cancerous tissues decreased in comparison with the number in noncancerous tissues, as the tumor size increased and histological grade decreased. In hyperplastic nodular lesions, the number was higher in nodular lesions than in the surrounding liver tissues in 4 of 7 AHs (57.1%) and 6 of 13 FNHs (46.2%). This could explain the reason why enhanced MRI, which utilizes the selective taken-up mechanism of chondroitin sulfate iron colloid and superparamagnetic iron oxide into the reticuloendothelial system of the liver and spleen, depicts well-differentiated HCC and AH at the same signal intensity as in the surrounding liver tissues. Our findings also indicate that there is a limitation in differentiating or diagnosing small HCC and hyperplastic nodular lesions by using enhanced MRI, which utilizes Kupffer cell functions.

[A boy highly suspected of hypersensitivity pneumonitis characterized by generalized mucosal lesions]

The case is a boy who developed progressive dyspnea and had since been followed over a long period time as a case of unknown fever without respiratory symptoms. He showed mucosal symptoms such as intraoral aphtha, eosinophilic pyuria and diarrhea and was clinically diagnosed as hypersensitivity pneumonitis. The affected child showed high levels of circulating immune complex, a decline in DLco on the respiratory function test and a decrease in CD 4/8 in bronchoalveolar lavage lymphocytes; furthermore, an antibody specific to Aureobasidium pullulans was positive in the precipitated antibody test. As for the immune function of the affected child during the follow-up, hypergammaglobulinemia and various immune abnormalities were observed. We thought the clinical feature of the affected child to be of pathophysiological value in dealing with unknown fever in childhood, so we reported our findings in this paper.

Pathomorphological study of Kupffer cells in hepatocellular carcinoma and hyperplastic nodular lesions in the liver

A pathomorphological study was conducted to clarify the localization of Kupffer cells in hepatocellular carcinoma (HCC) tissues and such hyperplastic nodular lesions as adenomatous hyperplasia (AH) and focal nodular hyperplasia (FNH). Materials were surgical specimens of 50 HCCs, 7 AHs, and 13 FNHs. These tissues were immunohistochemically stained with an anti-human macrophage antibody (anti-CD68 antibody). Among CD68-positive cells, short spindle-shaped cells were considered as Kupffer cells, and Kupffer cell numbers in tumor lesions and surrounding liver tissues of each specimen were comparatively examined. As a result, the number of Kupffer cells in well-differentiated HCC tissues less than 1 cm in diameter was 27.8 +/- 3.3 (mean +/- SE/025 mm2); in noncancerous tissues, it was 302 +/- 3.2, showing no statistically significant differences. The number of Kupffer cells in cancerous tissues decreased in comparison with the number in noncancerous tissues, as the tumor size increased and histological grade decreased. In hyperplastic nodular lesions, the number was higher in nodular lesions than in the surrounding liver tissues in 4 of 7 AHs (57.1%) and 6 of 13 FNHs (46.2%). This could explain the reason why enhanced MRI, which utilizes the selective taken-up mechanism of chondroitin sulfate iron colloid and superparamagnetic iron oxide into the reticuloendothelial system of the liver and spleen, depicts well-differentiated HCC and AH at the same signal intensity as in the surrounding liver tissues. Our findings also indicate that there is a limitation in differentiating or diagnosing small HCC and hyperplastic nodular lesions by using enhanced MRI, which utilizes Kupffer cell functions.

Intestinal adenocarcinoma with neuroendocrine cells in a clouded leopard (Neofelis nebulosa)

Adenocarcinoma of the small intestine was found in a 6-year-old clouded leopard. This tumour was characterized by the presence of goblet and neuroendocrine cells. The latter were labelled positively for either serotonin, somatostatin, neurotensin, gastrin or secretin. These neuroendocrine cells were reduced in number in most of the metastatic lesions, including those of the mesentery, diaphragmatic pleura, lungs, liver and heart, and squamous metaplasia was detected in some metastatic sites.