Construction of a morphological filter for detecting an event-related potential P300 in single sweep EEG record in children

A morphological filter for single sweep records of event-related potential (ERP) obtained in an auditory oddball paradigm, especially P300 waveform, was constructed. By combining four basic operations; erosion, dilation, opening and closing, we could derive a desired filter whose properties fit the current objectives. The morphological filter for the single sweep records of ERP was constructed by taking into account the features of the signal and noise components. The morphological filter had superior properties for distinguishing the signal from the noise even when both were within the same frequency band, as in case of children. The constructed morphological filter was evaluated by using the simulation data of ERP and then applied to the actual ERP data obtained from nine normal children. The constructed morphological filter was proved to be an appropriate tool for single sweep analysis of ERP.

[Word fluency in spinocerebellar degeneration]

Two types of verbal fluency task-initial letter fluency and category (semantic) fluency--were examined in eleven patients with spinocerebellar degeneration (SCD), twenty four patients with Parkinson disease (PD), and twenty control subjects without neurological signs and symptoms. All patients and subjects showed normal results from the screening test for dementia. The numbers of initial letter fluency were less than those of category fluency in all groups. For category fluency, patients with SCD or PD had significantly lower scores than controls. For initial letter fluency, patients with SCD produced significantly lower scores than controls, but patients with PD did not produce significantly lower scores than controls. It is considered that the poor performance on both initial letter and category fluency in patients with SCD or Pd was related to disturbance of semantic memory associated with subcortical impairment, and the poor performance on initial letter fluency in patients with SCD was caused by the initiation and retrieval problems based on disturbance of frontostriatal circuits and linguistic systems. Therefore, we suggested cerebellar hemisphere played a role on the order and timing of rule-based generation of letters.

DNA sequence and site of mutation of the GABA receptor of cyclodiene-resistant red flour beetle, Tribolium castaneum

Using polymerase chain reactions (PCR) on cDNA, the DNA sequence of a membrane spanning region of a GABA receptor of the red flour beetle, Tribolium castaneum was identified. The deduced amino acid sequence indicates that its basic structure is similar to the GABA receptor of Rdl type subunits of Drosophila melanogaster and of Blattella germanica. Particularly conserved are M1, M2 and M3 segments. Within this 146 amino acid stretch, the GABA receptor from the red flour beetle differed from corresponding ones from Drosophila and Rdl subunit of B. germanica by 12 and eight amino acids, respectively. By using an identical approach, the corresponding DNA region was sequenced from the cDNA of a cyclodiene-resistant strain of T. castaneum. While two points of mutation were found only one mutation in DNA was found to result in an amino acid shift. The site of mutation was at the 5th amino acid of the M2 cylinder where G to T conversion of the GCT codon resulted in a conversion of alanine to serine. This is qualitatively the same mutational switch of alanine to serine in resistant strains previously reported to have occurred in cyclodiene-resistant Drosophila melanogaster, Aedes aegypti and Blattella germanica, indicating that this amino acid change is the likely cause for evolution of the nerve insensitive type of resistance to cyclodiene insecticides.

Influence of filler addition to bonding agents on shear bond strength to bovine dentin

OBJECTIVES

The purpose of this study was to investigate the influence of adding filler particles to a bonding agent on dentin bond strength and of the temperature change during curing in order to determine the optimum filler level for an experimental bonding agent.

METHODS

Experimental light-cured bonding agents with microfiller (average size: 0.05 micrometers) content of 0, 10, 20, 30, 40, 50, 60, and 70 wt% were used with the Imperva Bond / Lite-Fil II A (Shofu) restorative material. Bovine incisors were mounted in self-cured resin, and the facial surfaces were prepared with 600-grit SiC paper. After dentin surface pretreatment with dentin primer, experimental bonding agents were applied to the dentin surface and bonded with resin composite. Ten samples per test group were stored in 37 degrees C water for 24 h, then shear tested at 1.0 mm/min. The temperature change of the bonding agent was monitored during the exthothermic polymerization reaction according to the method of ISO standard #4049. The peak temperature and the time required to reach peak temperature were recorded.

RESULTS

Bond strength to dentin and the temperature change were greatly affected by the filler level. Maximum dentin bond strength (14.3 +/- 2.3 MPa) was obtained with a filler level of 10 wt% and decreased with filler level higher than 30 wt% (10.4 +/- 1.7 MPa - 5.3 +/- 2.6 MPa). Peak temperature decreased and the time required to reach peak temperature increased with the higher filler levels. There were strong correlations between the bond strength and temperature change of experimental bonding agents.

SIGNIFICANCE

The initial setting behavior of bonding agents containing filler particles may be one of the important factors influencing dentin bond strength. When bonding agents with filler particles are used, it is important to determine if optimum filler levels exist in order to optimize the dentin bond strength.

[Antigenicity study of T-3761]

Antigenicity studies of T-3761, a new quinolone derivative, were conducted and the following results were obtained. 1. By active systemic anaphylaxis test in guinea pigs, neither immunogenicity nor allergenicity of T-3761 was noted. 2. By homologous 4-hour passive cutaneous anaphylaxis (PCA) test using the serum obtained from these guinea pigs, neither immunogenicity nor allergenicity of T-3761 was noted. 3. The potential of IgE antibody production in mice was examined by heterologous 24-hour PCA test in rats. But neither the potential of IgE antibody production nor allergenicity of T-3761 was noted. 4. By passive hemagglutination assay, we analysed the antibody titer in rats and dogs serum obtained from three-month toxicity repeated dose studies (oral and intravenously administration). But the hemagglutination response was negative and specific antibodies were not detected.

[Phototoxicity and photoallergenicity tests of T-3761]

Phototoxicity and photoallergenicity tests of T-3761 (oral or percutaneous administration) were carried out in guinea pigs. Phototoxicity test of T-3761 (oral administration) was done in rats, too. The following results were obtained. 1. Compared with comparative drugs in oral administration, phototoxicity of T-3761 was equal to that of ciprofloxacin, slightly stronger than that of nalidixic acid and weaker than those of ofloxacin, enoxacin, sparfloxacin and lomefloxacin. 2. A sensibility to phototoxicity of T-3761 in rats was weaker than that in guinea pigs. 3. Phototoxicity and photoallergenicity were not observed in application of T-3761 as 10% ointment. 4. Photoallergenicity was not observed in oral administration of T-3761.

Developmental brain changes investigated with proton magnetic resonance spectroscopy

Volume-selective proton magnetic resonance spectroscopy (1H-MRS) of the brain was performed with a 1.5 Tesla magnet in 47 healthy children and in six healthy adults. Peaks of N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) were observed in all cases, but a lactate peak was not observed. In the right parietal region. 1H-MRS revealed increases in the rations of NAAJCho and NAA/Cr and a decrease in Cho/Cr with advancing age. The most rapid changes were noted between one and three years of age. 1H-MRS of the right frontal region also was performed in 21 cases (20 children and one adult). In the right frontal region, there was an increase in the ratio of NAA/Cho and a decrease in Cho/Cr with advancing age, while a developmental change was not observed in the ratio of NAA/Cr. The ratios of both NAA/Cho and NAA/Cr were lower in the right frontal region than in the right parietal region. These results show that developmental changes and regional variation of metabolites are observed in 1H-MRS of the brain, and need to be considered in its application.

Proton magnetic resonance spectroscopy of brain in congenital myotonic dystrophy

Volume selective proton magnetic resonance spectroscopy of brain was performed on a 1.5 T magnet in 5 patients with congenital muscular dystrophy and compared to the results in 46 healthy children and 1 healthy adult. Peaks of N-acetyl aspartate, choline, and creatine but not lactate, were observed in both groups on proton magnetic resonance spectroscopy. Spectroscopy of controls revealed an increase with advancing age in the ratio of N-acetyl aspartate/choline and N-acetyl aspartate/creatine and a decrease in the choline/creatine ratio. In patients with congenital myotonic dystrophy, the N-acetyl aspartate/choline ratio did not increase with advancing age, but the N-acetyl aspartate/creatine ratio did. The choline/creatine ratio decreased with advancing age, which matched the results of controls. At any age older than 4 years, the N-acetyl aspartate/choline and N-acetyl aspartate/creatine ratios were lower in patients with congenital myotonic dystrophy than in controls. The choline/creatine ratio did not differ between congenital myotonic dystrophy and controls. These results suggest that in patients with congenital myotonic dystrophy N-acetyl aspartate decreases and there exists a developmental disorder of neurons in brain.

Thyroid ultrasonography in congenital isolated thyroid stimulating hormone deficiency

The effects of thyroid stimulating hormone (TSH) deficiency on thyroid development was examined using ultrasonography in a child with congenital isolated TSH deficiency. Ultrasound revealed the thyroid gland was one sixth normal volume, suggesting that TSH plays an important part in thyroid growth, but not a critical role in differentiation.

Increased serum type IV collagen 7-S levels in patients with hepatic metastasis

OBJECTIVE

The purpose of this study was to assess serum type IV collagen 7-S domain (IV 7-S) levels in colorectal cancer patients with hepatic metastasis and to investigate the relation between serum IV 7-S levels and type IV collagenase activities in tumor tissue.

METHODS

Tissue type IV collagenase activity and serum IV 7-S were measured in 50 colorectal cancer patients without hepatic metastasis and in 26 patients with hepatic metastasis.

RESULTS

Type IV collagenase showed significantly higher activities in colorectal cancer (n = 36) than in colorectal normal mucosa (n = 36) (p < 0.001), but significantly lower activities were shown in the hepatic metastatic tumor (n = 18) than in the primary tumor (n = 36) and normal liver tissue (n = 18) (p < 0.001). No significant correlation was found between type IV collagenase activities in the tumor and serum IV 7-S levels. Colorectal cancer patients with hepatic metastasis (n = 26) had significantly higher serum IV 7-S levels than those without hepatic metastasis (n = 50) (p < 0.001). Moreover, serum IV 7-S levels correlated significantly with hepatic metastatic tumor volume in patients with synchronous (r = 0.719, p < 0.001, n = 26) and in patients with metachronous (r = 0.910, p < 0.001, n = 16) hepatic metastasis.

CONCLUSION

We suggest that serum IV 7-S levels may increase in hepatic metastasis, not by the degradation of type IV collagen in the primary and secondary tumors, but by the enhanced production of type IV collagen responsive to hepatic metastasis. The measurement of serum IV 7-S levels might be a useful tumor marker of hepatic metastasis reflecting hepatic metastatic tumor volume.

[Clinical evaluation of 99mTc-MAG3 as a radiotracer to assess the function of transplanted kidney: comparison with 123I-OIH]

99mTc-MAG3 (mercaptacetyl glycilglycilglycine) is a newly developed radiopharmaceutical for the functional imaging of kidneys. We evaluated the clinical usefulness of 99mTc-MAG3 in 12 cases (7 men and 5 women, aged from 18 to 57 years old) with transplanted kidney, and compared it with 123I-OIH (o-iodohippurate). Immediately after bolus injection of 300 MBq of 99mTc-MAG3, first pass images (1 frame/3 sec for 1 min) and dynamic renal images (1 frame/60 sec for 30 min) were recorded. In 10 of 12 cases, the same examination was carried out using 37 MBq of 123I-OIH within 2 weeks. Because of its larger dose and suitable gamma-ray energy, 99mTc-MAG3 provided much better images than 123I-OIH, particulary among first pass images. Effective renal plasma flow (ERPF) calculated from the clearance of 99mTc-MAG3 was less (about 70%) than that of 123I-OIH, however, a strong correlation (r = 0.98, p < 0.001) was observed between the ERPF values of the two radiotracers. No adverse effects were caused by 99mTc-MAG3. Our data suggested that 99mTc-MAG3 was a promising radiopharmaceutical with which to evaluate regional dynamic renal function.

[Proton MR spectroscopy of the brain in patients with congenital myotonic dystrophy]

Volume selective proton MR spectroscopy (1H-MRS) of the brain was performed on a 1.5T magnet in five patients with congenital muscular dystrophy (CMyD), 46 healthy children, and one healthy adult. Peaks of N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) were observed in both patients and control groups on 1H-MRS, but lactate was not observed. 1H-MRS revealed an increase in the ratio of NAA/Cho and NAA/Cr, and a decrease in Cho/Cr ratio with age in control subjects. In patients with CMyD, the values of NAA/Cho ratio did not increase with age. The values of NAA/Cr ratio decreased with age. The values of Cho/Cr ratio decreased with age in both patient and control groups. At age more than 4 years, the values of NAA/Cho and NAA/Cr ratios were lower in patients with CMyD than in controls. The values of Cho/Cr ratio did not differ between CMyD and controls. These results suggest that in patients with CMyD, there is an NAA decrease and a developmental disorder of neurons in the brain.

Pulmonary edema induced by angiotensin II in rats

We performed this study to demonstrate the experimental procedure for inducing pulmonary edema by angiotensin II (AT II) in rats and to determine the mechanism of hemodynamic pulmonary edema. In the pilot study, 10 micrograms/ml of AT II was found to be adequate as the edematogenic dose for inducing pulmonary edema. The edematogenic dose of AT II was intravenously given to rats pretreated with 20 mg/kg of an AT II-receptor antagonist, E 4177 (3-[(2'-carboxybiphenyl-4-yl)methyl]-2-cyclopropyl-7-methyl-3H- imidazo[4,5-b]pyridine), and to rats given 10 mg/kg of an alpha-adrenergic blocker, phentolamine. Similarly, pulmonary edema was induced by 25 micrograms/ml of adrenaline in rats pretreated with E 4177 (20 mg/kg) and rats with no pretreatment. E 4177 completely suppressed the development of AT II-induced pulmonary edema, whereas phentolamine could not. On the contrary, E 4177 could not suppress the development of adrenaline-induced pulmonary edema. We concluded that AT II-induced pulmonary edema will develop via the specific AT II receptor without the indirect action of adrenaline.

Polymorphism of immunoglobulin heavy chain switch region gene in children with severe IgA nephropathy

We examined restriction fragment length polymorphisms (RFLPs) of the switch region genes of the IgM (S mu) and IgA1 (S alpha 1) heavy chain in 78 Japanese children with IgA nephropathy and 88 normal Japanese controls. Genomic DNA obtained from patients and controls was digested with the restriction endonuclease SacI, transferred to nylon membrane using Southern blot procedure, and hybridized with a DNA probe homologous to S mu. This probe detects RFLPs at the S mu and S alpha 1 loci by enhanced chemiluminescence. The genotypic frequency of the S mu and S alpha 1 alleles in patients with IgA nephropathy was similar to normal controls. However, there was a significant association of genotypes with the pathological severity. There was a decreased frequency of the 2.6/2.1 kb S mu heterozygous genotype in patients showing diffuse mesangial proliferation compared to controls or patients showing minimal or focal mesangial proliferation. Our results suggest that immunoglobulin heavy chain switch region genes may not influence susceptibility to IgA nephropathy in children, but may influence the pathological expression of childhood IgA nephropathy.

Dimeric chemotactic peptides discriminate between chemotaxis and superoxide production of human neutrophils

A series of dimeric fMLPs were synthesized by cross-linking with hydrophilic linkers, mono-, di-, tri-, and tetraethylene glycols. All of the dimers showed higher activities than monomeric fMLP in chemotaxis assays for human neutrophils. The magnitude of the activity enhancement was dependent on the linker length. On the other hand, production of superoxide anion was not as enhanced as chemotaxis. The experimental results indicate that these dimers, especially the triethylene glycol-bridged fMLP dimer, D-fMLP-G3, are selective agonists for chemotaxis. In order to distinguish between biological activities and intracellular signaling, rapid mobilization of the intracellular calcium was also measured. D-fMLP-G3 strongly enhanced the calcium mobilization. These results suggest that chemotaxis was correlated with the increase of the intracellular calcium concentration, whereas NADPH oxidase was not activated to generate superoxide by this elevation of cytoplasmic calcium caused by the dimeric ligand, D-fMLP-G3. The dimeric fMLPs might act as useful ligands for studying the intracellular signaling mechanisms of human neutrophils.

[Intraportal infusion of 5-FU and lipiodol-aclarubicin after hepatic resection for colorectal liver metastasis]

Fifty-five patients with hepatic metastasis from colorectal cancer underwent curative hepatic resection. Postoperative intraportal infusion of 5-fluorouracil (500mg per day) for 14 days from 21 postoperative days (POD) and lipiodol-aclarubicin (40mg) at 35 POD was carried out in twenty-eight patients for reducing the recurrence in the remnant liver and improving the prognosis. Twenty-seven patients had hepatectomy alone as controls. Intraportal infusion chemotherapy did not induce any hepatotoxicity and hematologic severe abnormalities. The cumulative survival rates for the infusion group and the control group, respectively, were 89.3% and 63.0% at 1 year; 55.2% and 43.3% at 2 year; 27.0% and 27.5% at 3 year. The survival rate for the infusion group was significantly higher than that for the control group at 1 year (p < 0.05). No difference of the recurrent rate in the remnant liver was found between the two groups. It is suggested that intraportal infusion chemotherapy after curative hepatic resection for colorectal liver metastasis might improve survival rate at the early postoperative period. Intraportal infusion chemotherapy could be an effective adjuvant therapy especially in the patients with bilateral and multiple hepatic metastasis.

Epidemiological characteristics of human immunodeficiency virus type-2 infection in Africa

There are things yet to be clarified about African HIV-2 infection, compared to HIV-1 infection. However, the epidemiological characteristics have gradually been elucidated through various studies. HIV-2 infection is believed to have existed in the 1960s in Africa and is presently epidemic in West Africa. The HIV-2 seropositive rate for the general population is higher in urban regions than in rural areas. The peak age of persons infected with the HIV-2 tends to be higher than that of persons infected with the HIV-1, but no sex difference was recognized between the HIV-2 and HIV-1 seropositive rates. Sexual contact, mother-to-child transmission and blood transfusion have been confirmed as HIV-2 transmission modes. Prostitutes and patients with other STD are recognized as being high-risk groups for the HIV-2 infection. Patients who are infected with both HIV-1 and HIV-2 have also been identified, but it is suggested that the pathogenicity of HIV-2 is lower than that of HIV-1.

Endoscopic ultrasonographic abnormalities and lower esophageal sphincter function in reflux esophagitis

Endoscopic ultrasonography of the lower esophagus was performed in 25 patients with reflux esophagitis and 13 age-matched controls. Thickening of the esophageal wall and abnormalities of its architecture were detected. As these morphological changes became more extensive, the lower esophageal sphincter pressure and the decrease of sphincter pressure on relaxation were both progressively reduced. There was a significant correlation between morphological abnormalities and lower esophageal function. Our results suggest that inflammatory damage to the muscle layer of the lower esophagus may impair lower esophageal sphincter function further, especially in patients with advanced esophagitis.

Development of the brainstem and cerebellum in autistic patients

Studies of magnetic resonance images have revealed morphological disorders of the brainstem and cerebellum in autistic children and adults. When we studied development of the brainstem and cerebellum in autistic patients, we found that although the brainstem and cerebellum significantly increased in size with age in both autistic patients and controls, these structures were significantly smaller in autistic patients than in controls. The speed of development of the pons, the cerebellar vermis I-V and the cerebellar vermis VI-VII was significantly more rapid in autistic patients than in the controls. However, the speed of development of the other brain structures in the posterior fossa did not differ between autistic patients and controls. The regression intercepts of the brainstem and cerebellum as well as those of their components were significantly smaller in autistic patients than in controls. Results suggest that brainstem and vermian abnormalities in autism were due to an early insult and hypoplasia rather than to a progressive degenerative process.

[A case of tuberculous mesenteric lymphadenitis and peritonitis with symptoms of acute abdomen]

Both of tuberculous mesenteric lymphadenitis and tuberculous peritonitis are now rather rare in parallel with the decrease of the incidence of tuberculosis as a whole. Here, we report a case of tuberculous mesenteric lymphadenitis complicated with tuberculous peritonitis. A 28-year-old man was admitted to our hospital with pulmonary tuberculosis. Antituberculous chemotherapy was started and his chest X-ray findings were improved. After 11 weeks of the treatment, high fever of 39.0 degrees C developed suddenly and he complained right lower abdominal pain. During laparotomy performed on suspicion of acute appendicitis, swelling of mesenteric lymph-nodes, numerous miliary tubercles on mesentery and turbid ascites were noticed. Diagnoses of tuberculous mesenteric lymphadenitis and tuberculous peritonitis were confirmed by bacteriological and histological examinations of lymph-nodes and tubercles. Ileocecal resection was performed and clinical course after the surgery was favourable.