[Clinical studies on azithromycin in pediatrics]

Fine granules or capsules of azithromycin (AZM) were given to 32 pediatric patients for the treatment of the following diseases: pharyngitis in three cases; tonsillitis in one; bronchitis in six; pneumonia in six; mycoplasmal pneumonia in 14; pertussis and enteritis in one, each. Effectiveness of AZM was evaluated in 30 cases and the drug was rated "excellent" in 18 patients, "good" in 11 and "fair" in one, resulting in a total efficacy rate of 96.7%. Three strains of bacteria were isolated from 3 patients as the causative organisms including: Streptococcus pneumoniae, Haemophilus influenzae and Haemophilus parainfluenzae, from three different patients, respectively. One patient complained of mild diarrhea, another patient mild urticaria. Abnormal laboratory test results were reported as follows: one patient showed a slight decrease in leukocyte count, three patients showed slight increases in eosinophils, and one patient had slight elevations in GOT and GPT. The above results suggest that AZM is a useful antibiotic drug in the treatment of pediatric patients with various bacterial infections.

Crystallization and preliminary X-ray analysis of 3-isopropylmalate dehydrogenase from the moderate facultative thermophile Bacillus coagulans

Three crystalline forms of 3-isopropylmalate dehydrogenase from the moderate facultative thermophile Bacillus coagulans were obtained by hanging-drop vapor-diffusion methods. One of them, which had crystallized under slightly milder conditions than the others, was suitable for X-ray analysis. Its asymmetric unit contains one dimeric molecule and the solvent content is higher than in other protein crystals. The crystal structure was solved in a preliminary manner by the molecular-replacement technique.

D-type cyclin expression is decreased and p21 and p27 CDK inhibitor expression is increased when tsBN462 CCG1/TAFII250 mutant cells arrest in G1 at the restrictive temperature

BACKGROUND

The tsBN462 temperature-sensitive mutant hamster cell line exhibits cell cycle arrest and apoptosis at the restrictive temperature of 39.5 degrees C, due to a point mutation in the CCG1/TAFII250 gene, which encodes a component of the general transcription factor TFIID.

RESULTS

We now report that CCG1/TAFII250 persisted as a complex with TBP and associated proteins (TAFs) in tsBN462 cells at the restrictive temperature. FACScan analysis revealed that the tsBN462 mutation resulted in a failure to progress out of G0 into G1. Using two-dimensional gel electrophoresis we observed a decrease in the synthesis of several proteins, starting in the middle of the G1 phase, becoming very pronounced during late G1. The expression of the immediate early genes c-fos, c-jun and c-myc was normally induced by serum treatment of quiescent cells at the restrictive temperature, whereas expression of cyclins A, D1 and D3 was reduced. Expression of the cyclin-dependent kinase (CDK) inhibitor proteins p21 and p27 was enhanced. Consistent with the decreased cyclin D and increased p21/p27 expression, we found that phosphorylation of Rb was decreased at 39.5 degrees C. Cyclin A-, E- and Cdk2-associated histone H1 kinase activity was reduced concomitantly with the increase in p21 protein.

CONCLUSION

Decreased cyclin/Cdk kinase activity and decreased Rb phosphorylation are possible causes of G1 cell cycle arrest in tsBN462 cells at the restrictive temperature.

Esophagocardioplasty for achalasia in closure of a complicated esophagobronchial fistula

We report a rare case of benign esophagobronchial fistula associated with achalasia. The fistula healed spontaneously after esophagocardioplasty with a gastric patch, suggesting the utility of this procedure.

Type II citrullinemia associated with neutropenia

A 37-year-old Japanese man was admitted with delirium and hyperammonemia. He was diagnosed as having type II citrullinemia because of an elevated citrulline level on amino acid analysis and very low hepatic argininosuccinate synthetase activity. He also showed a low neutrophil count and a low serum level of granulocyte colony-stimulating factor. Reduced production of this cytokine and/or impairment of its feedback regulation by the neutrophil count may have played a role in the neutropenia of this patient.

Effect of biotin on ammonia intoxication in rats and mice

The effects of biotin on ammonia concentration in blood and brain were evaluated in hyperammonemic rats and mice. Rats were injected with 5 mmol/kg BW of ammonium acetate, and mice were injected with 10 mmol/kg BW. Increases in blood ammonia levels in rats 15-30 min after ammonia loading were prevented by treatment with 0.2 ml/100 g BW of biotin or 0.04 ml/100 g BW of arginine-glutamate with statistical significance. Blood ammonia levels after ammonia loading were lower, although not significantly, in the arginine glutamate-treated rats than in the biotin-treated animals. In mice also, increases in blood and brain ammonia levels after ammonia loading were prevented by the administration of biotin. The decrease in brain glutamate and aspartate after ammonia loading was lower and the brain glutamine level was higher in biotin-treated mice than in the controls. These findings indicate the protective effect of biotin against ammonia intoxication.

Apoptosis is induced in BHK cells by the tsBN462/13 mutation in the CCG1/TAFII250 subunit of the TFIID basal transcription factor

A temperature-sensitive (ts) mutant of the BHK21 cell line derived from golden hamsters, tsBN462 has a mutation in the gene encoding the largest subunit of the TFIID complex, TAFII250/p230/CCG1, and arrests in the G1 phase at the nonpermissive temperature, 39.5 degrees C. We found that tsBN462 cells underwent apoptosis following growth arrest at 39.5 degrees C, suggesting a role for CCG1 as a repressor of apoptosis. By electron microscopic observation, tsBN462 cells at 39.5 degrees C showed characteristic features of apoptosis. Apoptosis was not suppressed by expression of Bc1-2 or the adenovirus E1B 19 kDa protein. Cell death was suppressed completely by expression of wild-type CCG1 and partially by wild-type p53, a growth suppressor protein. Cell cycle arrest induced by p53 may help survival of tsBN462 cells at 39.5 degrees C. Apoptosis was accelerated in SV40 large T antigen-transformed tsBN462 cells at 39.5 degrees C where SV40 large T antigen formed a complex with p53, implying that the apoptosis of tsBN462 cells at 39.5 degrees C occurred in a p53-independent manner. Our results suggest that CCG1/TAFII250 is required for the expression of factors regulating apoptosis.

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.

[Clinical studies on SY5555 in pediatrics]

SY5555 in dry syrup (powder which is dissolved before use) or tablet form was given orally to 21 children with acute bacterial infections including 4 with acute pharyngitis, 5 with acute tonsillitis, 7 with acute bronchitis, 2 with acute gastroenteritis, 1 each with scarlet fever, acute lymphadenitis and urinary tract infection. Good to excellent clinical responses were obtained in all of the 21 patients and 8 of 11 strains found as causative organisms in these cases were eradicated and 3 strains were decreased. Loose stools were observed in 3 cases and eosinophilia was observed in 1 case. From the above clinical results, it appears that SY5555 is a useful antibiotic for the treatment of pediatric patients with various bacterial infections.

Minimum essential region of CCG1/TAFII250 required for complementing the temperature-sensitive cell cycle mutants, tsBN462 and ts13 cells, of hamster BHK21 cells

CCG1/TAFII250, the largest subunit of the TFIID complex, is mutated in ts cell cycle mutants of BHK21 cells, ts13 and tsBN462, which have a promoter-selective transcriptional defect. A series of deletion mutants of CCG1 cDNA were prepared and transfected into these mutants, in order to identify functional domains of CCG1 required for the complementation of ts 13/BN462 mutation. We determined the minimum size of CCG1:CCG1ME, essential for complementing the ts mutation, which possessed one proline cluster, an HMG1-like domain, and a nuclear localization signal, but which lacked the bromo domains and the acidic phosphorylation sites for casein kinase II common to transcriptional activators. It encodes a protein of 140 kDa. These characteristics of CCG1ME correspond to yeast TAFII145, the yeast homolog of human TAFII250. CCG1ME bound to TBP, creating its own TFIID complex different from that of the endogenous mutated CCG1 in ts+ transformants of tsBN462 cells.

[Clinical studies on cefozopran in pediatrics]

Cefozopran (CZOP, SCE-2787) was given intravenously to 12 children with acute bacterial infections including 9 with acute pneumonia, 1 each with acute pyothorax, impetigo and staphylococcal scalded skin syndrome. Good or excellent clinical responses were obtained in all of the 12 patients and bacterial eradications were achieved for all 10 strains identified in these cases. No side effects were noted. Eosinophilia was observed in one case, however. From the above clinical results, it appears that CZOP is a useful antibiotic for treatment of pediatric patients with various bacterial infections.

Mammalian cells have two functional RCC1 proteins produced by alternative splicing

Previously we cloned two human RCC1 cDNAs that differed in their noncoding region. In this study, we have found new human and hamster RCC1 cDNAs, which have an even more different coding region from that of the previously cloned RCC1 cDNAs yet can complement the RCC1 mutation in the tsBN2 cell line. The newly found RCC1 cDNAs encode a protein (designated as RCC1-I) that has an insertion of 31 (human) and 13 (hamster) amino acids at valine25 in the N-terminal region outside the RCC1-seven repeat. The inserted nucleotide sequence was searched for, within the human RCC1 genomic sequence that had already been determined, and was found to be located between the 6th and 7th exons, designated as the 6′ exon. Both the 5′ and 3′ ends of the 6′ exon correspond to the GT-AG rules for splicing, indicating that human RCC1-I mRNAs are produced by alternative splicing. The finding that both humans and hamsters have the insertion at the same RCC1 site suggests that the pattern of alternative splicing in the RCC1 gene has been conserved through evolution.

Effect of H2-receptor antagonists cimetidine and famotidine on interdigestive gastric motor activity and lower esophageal sphincter pressure in progressive systemic sclerosis

The effect of the H2-receptor antagonists cimetidine and famotidine on interdigestive gastric motor activity and lower esophageal sphincter pressure was assessed in 41 patients with uncomplicated progressive systemic sclerosis. There was no significant change in gastric phasic motor activity after the intravenous administration of cimetidine (n = 6), famotidine (n = 13), and physiological saline (n = 15), or the intragastric infusion of 7% sodium bicarbonate (n = 7). The lower esophageal sphincter pressure was increased significantly by both cimetidine and famotidine, but only famotidine caused a significant pressure rise in patients without an increase of gastric motility. Cimetidine and physiological saline produced a similar pattern of change in the esophageal sphincter pressure, as did famotidine and sodium bicarbonate. These findings suggest that the inhibition of acetylcholinesterase activity and gastric acid secretion may be involved in the respective mechanisms of action of cimetidine and famotidine.

Hyaluronan, cartilage destruction and hydrarthrosis in traumatic arthritis

The concentrations of hyaluronan (HA) and chondroitin sulfate (CS) in synovial fluids from patients with traumatic arthritis (TA) with and without hydrarthrosis were measured. The CS in synovial fluids was determined as a marker of cartilage destruction by high performance liquid chromotography. The concentration of HA in synovial fluids was lower in patients with hydrarthrosis than in healthy volunteers and patients with TA without hydrarthrosis, whereas the total amounts of HA and CS and the concentration of CS were higher in patients with hydrarthrosis. To investigate the relation between hydrarthrosis and production of HA in synovial tissues, TA synovial tissue biopsies were stained for HA with biotinylated HA binding region. The intensity of HA staining was higher in specimens from patients with hydrarthrosis than in normal and TA without hydrarthrosis specimens. Thus, there may be a correlation between hyperproduction of HA, cartilage destruction and increase in fluid volume in TA.

The CCG1/TAFII250 gene is mutated in thermosensitive G1 mutants of the BHK21 cell line derived from golden hamster

The CCG1 cDNA encoding a general transcription factor, TAFII250, complements a thermosensitive (ts) cell cycle mutant, tsBN462, of the BHK21 cell line, which arrests in the G1 phase at the restrictive temperature. In order to clarify whether the CCG1 is mutated in tsBN462 cells or a suppressor of tsBN462 mutation, CCG1 cDNAs isolated from parental wild-type (wt) BHK21 and tsBN462 cell lines were sequenced. Comparison of the nucleotide (nt) sequences showed a single transition: G-->A in the second base of codon 690 of the tsBN462 CCG1 cDNA, resulting in a Gly690-->Asp change. The BHK CCG1 cDNA, but not the tsBN462 CCG1 cDNA, complemented the tsBN462 mutation, proving that the CCG1 is mutated in the tsBN462 cell line. Thus, the defect of general transcription factor, TAFII250, is suggested to cause a G1 arrest in the cell cycle.

Structure of the human CCG1 gene: relationship between the exons/introns and functional domain/modules of the protein

The human CCG1 gene, encoding CCG1/TAFII250/p250, was isolated by complementing tsBN462, a mutant BHK21 cell line that shows cell-cycle arrest at high temperature. Using the cDNA as a probe, the locations of exon-intron junctions were determined in the genomic DNA. Thirty-eight exons ranging from 68 to 219 bp in size were found. All the exon-intron junctions followed the GT-AG rule. Using a newly developed method, we performed a module analysis of the CCG1 protein. The functional domain previously predicted in CCG1 was further confirmed to be encoded in a single predicted module that is the minimal functional unit in the protein. The boundaries of the predicted modules show a close correlation to the intron/exon junction of CCG1. The entire gene, at least 110 kb long, has been recovered in a YAC, which provides a route to the further study of module function.