The C-terminal silencing domain of Rap1p is essential for the repression of ribosomal protein genes in response to a defect in the secretory pathway

We have previously shown that a functional secretory pathway is essential for continued ribosome synthesis in Saccharomyces cerevisiae. When a temperature-sensitive mutant defective in the secretory pathway is transferred to the non-permissive temperature, transcription of both rRNA genes and ribosomal protein genes is nearly abolished. In order to define the cis -acting element(s) of ribosomal protein genes sensitive to a defect in the secretory pathway, we have constructed a series of fusion genes containing the CYH2 promoter region, with various deletions, fused to lacZ. Each fusion gene for which transcription is detected is subject to the repression. Rap1p is the transcriptional activator for most ribosomal protein genes, as well as having an important role in silencing in the vicinity of telomeres and at the silent mating-type loci. To assess its role in the repression of transcription by the defect in the secretory pathway, we have introduced rap1 mutations. The replacement of wild-type Rap1p by Rap1p truncated at the C-terminal region caused substantial attenuation of the repression. Furthermore, we have demonstrated that the Rap1p-truncation affects the repression of TCM1 , encoding ribosomal protein L3, which has no Rap1p-binding site in its upstream regulatory region. These results suggest that the repression of transcription of ribosomal protein genes by a secretory defect is mediated through Rap1p, but does not require a Rap1p-binding site within the UAS.

[Retropharyngeal abscess in an adult and an elderly woman]

Retropharyngeal abscess is reported to be decreasing in frequency in recent years. We report two cases of retropharyngeal abscess that were diagnosed within four years in Department of Otorhinolaryngology, Gifu University Hospital. Case 1 was a 36-year-old male who was suggested to have an abscess as primary infection and case 2 was a 71-year-old female whose abscess seemed to be a secondary infection following unknown primary infection. Endoscopic or open neck drainage as well as antibacterial chemotherapy mainly with combinations of flomoxef and clindamycin in the case 1 and piperacillin and clindamycin in the case 2 was successfully carried out. They were discharged an 15-day and 24-day after operation in the cases 1 and 2, respectively. A 30 min. culture after sample collection on operation demonstrated aerobe-anaerobe mixed infection in both cases; three aerobes and four anaerobes in the case 1 and three aerobes and two anaerobes in the case 2. These results suggest that retropharyngeal abscess may be a complicated infection involving more bacterial species than has been commonly believed. Measuring susceptibility of isolates to antimicrobial agents, a strain of Capnocytophaga sp. and a strain of anaerobic gram-negative rod were highly resistant to piperacillin, cefroxine and ofloxacin. It is important for adequate antibacterial chemotherapy to grasp the bacteriology of retropharyngeal abscess and analyze susceptibility of antimicrobial agents.

Acute granulomatous myringitis

This case report describes five cases of acute granulomatous myringitis treated during the nine-year period from 1987 to 1996. Otorrhoea and slight otalgia were the two major complaints. Findings included the appearance of a granulomatous bulge along the handle of the malleus or on the eardrum. No cases displayed eardrum perforation. No similarities were noted in patient age, sex or affected side. Treatment consisted of removal of the granuloma with a small cup forceps plus cauterization with 20 per cent trichloracetic acid. Two or three treatments resulted in complete healing, and average time to healing was 30 days, with no recurrences. Because it differs so distinctly from the more common chronic myringitis--characterized by mild symptoms, erosion and perforation of the eardrum with little granulomatous change, and a longer time to healing with frequent recurrence--the authors conclude that acute granulomatous myringitis should be regarded as a separate entity.

A new nomenclature for the cytoplasmic ribosomal proteins of Saccharomyces cerevisiae

The availability of the complete sequence of the Saccharomyces cerevisiae genome has allowed a comprehensive analysis of the genes encoding cytoplasmic ribosomal proteins in this organism. On the basis of this complete inventory a new nomenclature for the yeast ribosomal proteins is presented.

Central administration of PACAP stimulates gastric secretion mediated through the vagal pathway in anesthetized rats

Pituitary adenylate cyclase activating polypeptide (PACAP) is a neuropeptide that was originally isolated from ovine hypothalamic tissue. The peptide has two amidated forms, PACAP38 and PACAP27. In this study, we examined the effects of centrally administered PACAP38 and PACAP27 on gastric secretion in anesthetized rats. Centrally administered PACAP stimulated gastric acid and pepsin secretion in a dose-dependent manner. PACAP38 was 1.5-2 times more potent than PACAP27 on gastric secretion. By contrast, intravenously administered PACAP38 had no effect on basal or pentagastrin-stimulated gastric secretion. PACAP6-38, a PACAP antagonist, by itself at high doses also stimulated gastric and pepsin secretion, but at lower doses had no effect. Centrally administered PACAP6-38 at a dose that had no effect on gastric secretion, atropine pretreatment, or vagotomy pretreatment, suppressed the stimulatory effect of PACAP38. It is concluded that centrally administered PACAP may have a regulatory effect on gastric secretion through PACAP receptors and the vagal pathway.

Further experience with the antireflux valve to prevent ascending cholangitis in biliary atresia

BACKGROUND/PURPOSE

The intussusception-type antireflux valve is a mechanism introduced by Nakajo, who reported the results of his initial 17 cases in 1990. This report summarizes our further experience with new patients, together with follow-up results of the cases previously reported by Nakajo.

METHODS

In total, 46 new patients who had biliary atresia underwent portoenterostomy at the authors' two units. The authors hoped to construct the intussuscepted antireflux valve in the Roux-en-Y loop, whenever possible, at the time of hepatic portoenterostomy.

RESULTS

Among the 46 patients, one case each was found to be too young or too old to have the valve constructed during the surgery. In another case, the Roux-en-Y loop became too short after repeated revisions of the portoenterostomy. In another patient, the valve was first constructed but later removed because of jejunal perforation near the valve. In the last patient, the valve was not constructed for unspecified reasons. The authors constructed the antireflux valve in 42 patients, but it was maintained in 41. In one case, the valve truly prevented reflux of the intestinal juice during an episode of intestinal obstruction. The valve was found to be incompetent in one patient 5 years after the initial surgery.

CONCLUSION

The incidence of cholangitis was high in patients with postoperative cystic dilatation of the intrahepatic bile ducts, and low in those without it.

Laboratory diagnosis of acute measles infections in hospitalized children in Zambia

Laboratory diagnosis of measles infection is rarely performed in developing countries and tends to depend on clinical symptoms alone. We evaluated detection of immunoglobulin M (IgM) antibodies for confirmation of acute measles infection in Zambia. In 149 hospitalized children with clinical diagnosis of measles, IgM antibodies were detected in 88.6% (132/149). The IgM-positive rate increased with time after onset of skin rash and all samples were positive after 4 days. In addition to IgM antibody test, virus isolations from throat swabs using B95a cells were also performed. These were positive in only 20.9% (14/67), and both IgM and virus isolation in combination increased the positive rate to 92.5% (62/67). Vaccinated children had higher neutralizing (Nt) antibody responses and, among IgM-negative patients, all 4 vaccinated children had high Nt antibodies while all 10 unvaccinated children had negative or low Nt results. The IgM antibody test was proved to be a sensitive method for laboratory confirmation of measles virus infection in developing countries.

Epidemiology of influenza virus infections in children with acute respiratory infections in Zambia

A viral aetiological and epidemiological study of acute respiratory infections (ARI) in children was carried out in Lusaka, Zambia between June 1993 and September 1995. A total of 3,760 throat swab specimens were collected for virus isolation from children under 5 years of age who had ARI and were attending three health centres in Lusaka. Between June and November 1993, 52 cases of the influenza A/H3N2 viruses were isolated. Between May and July 1994, 34 influenza B cases were isolated. In 1995, one A/H3N2 influenza virus was isolated in January and then the same type of influenza virus was isolated from 55 samples between June and August. The isolation rate of influenza virus was highest at 14.3% (20/139) in August 1993, at 15.1% (18/119) in June 1994 and at 25.4% (43/169) in July 1995. This is the first report of a consecutive study of influenza virus infections in Zambia and the results reveal that influenza virus infections are one of the most important pathogens of ARI in children in the cool, dry season (June-August) in this country.

Focal microcirculation disorder induced by photochemical reaction in the guinea pig cochlea

A small region of microcirculation disorder in the cochlea of the guinea pig could be induced by a photochemical reaction. Photoillumination to the cochlea was done after systemic infusion of Rose Bengal (RB). The lateral wall of the second or third turn of the cochlea was illuminated for 10 min with a 1 mm diameter focused green light supplied by a xenon lamp. Degeneration of the stria vascularis (SV) was observed by a scanning electron microscope at 60-300 min after illumination. The range of length of degenerated area in the SV was from 111 to 1800 microns, with a mean of 760 microns. The organ of Corti along the illuminated lesion of the SV was well preserved in all animals at 60-300 min. In contrast, degeneration of sensory hair cells and scar formation in the SV were observed in the focal lesions of the three animals killed 1 week after illumination. The increase of diameter in the vessel of the SV from the radiating arteriole, the vessel of basilar membrane (VSBM) and limbus vessel (LVS) were observed in the illuminated area with diaminobenzidine (DAB) staining. These findings suggest that segmental microcirculation damage occurred in the SV and modiolus. In physiological studies, compound action potentials (CAP) were evaluated. Endocochlear potentials (EP) were also measured at the second turn under three different situations (groups A, B and C). A photochemically induced lesion was created at the site of EP measurement (group A), a site in the second turn 1 mm from the EP measurement site (group B) and a site in the third turn adjacent to the EP measurement site (group C). Threshold shift of CAP (up to 5.6 +/- 1.8 dB SPL) and reduction of EP (down to 11.4 +/- 10.7 mV) in the photochemically injured location were detected during about 15 min. EP did not recover to the predamaged level (79.9 +/- 3.7 mV) during 20 min. The morphological and physiological changes were not observed in the control group with illumination only. There were no significant decreases in EP values at the sites 1 mm from the lesion (group B) and at the inferior turn adjacent to the lesion (group C) compared to the marked decrease at the site of the photochemically induced lesion (group A). These findings suggest that CAP and EP are significantly affected by the interruption of segmental blood supply in the cochlea and remarkable decrease of EP occurs in the focal region of the guinea pig cochlea. We conclude that a localized blood circulation disorder induced by the photochemical reaction can make a focal lesion in guinea pig cochlea morphologically and physiologically.

Interspecies transmission of influenza C virus between humans and pigs

The antigenic and genetic characteristics of the 18 human strains of influenza C virus isolated in Yamagata and Sendai Cities, Japan between January 1991 and February 1993 were investigated. Antigenic analysis with monoclonal antibodies to the hemagglutinin-esterase glycoprotein showed that the isolates could be divided into three distinct groups closely related to C/Yamagata/26/81, C/Aichi/1/81 and C/Mississippi/80, respectively. T1-oligonucleotide fingerprinting of total vRNA revealed that the six isolates belonging to the C/Yamagata/26/81 virus group had the genomes greatly similar to one another but considerably different from those of the 1988/1990 isolates (except C/Yamagata/10/89) of the same antigenic group. Comparison of total or partial nucleotide sequences of the seven RNA segments of the three strains (C/Miyagi/3/91, C/Miyagi/9/91 and C/Miyagi/2/92) representative of the 1991/1993 strains of the C/Yamagata/26/81 virus group with those of the previous influenza C isolates obtained from humans and pigs during 1980/1989 showed that the 1991/1993 strains, like C/Yamagata/10/89, are more closely related to viruses isolated from pigs in Beijing, China in 1981/1982 than to any of the isolates from humans. This observation suggests strongly that interspecies transmission of influenza C virus between humans and pigs has occurred in nature, although it is not known whether the virus has been transmitted from pigs to humans or from humans to pigs.

Ultrastructural localization of the Na-K-Cl cotransporter in the lateral wall of the rabbit cochlear duct

Localization of the immunoreactivity in the lateral wall of the rabbit cochlear duct was examined using a post-embedding immunogold method with a polyclonal antiserum raised against the rabbit parotid Na-K-Cl cotransporter. In the stria vascularis, the labeling was significant on the basolateral membrane infolding of marginal cells, whereas no labeling was seen on the luminal membrane of these cells. Immunoreactivity was also detected on the cell membranes of various other cells. These include fibrocytes of the spiral ligament and the spiral prominence, and vascular endothelial cells in the stria vascularis and the spiral ligament. In contrast, virtually no gold particles were seen on the membrane of intermediate cells, basal cells of the stria vascularis, the epithelial cells of the spiral prominence, or Reissner's membrane. Our result on the localization of the Na-K-Cl cotransporter in marginal cells is consistent with electrophysiological studies (Wangemann et al. (1995) Hear. Res. 84, 19-29). Our result on fibrocytes is discussed in relation to K+ circulation into endolymph from perilymph (Schulte and Steel (1994) Hear. Res. 78, 65-76).

RIC1, a novel gene required for ribosome synthesis in Saccharomyces cerevisiae

We isolated a temperature-sensitive mutant of Saccharomyces cerevisiae in which transcription both of ribosomal protein genes and of ribosomal RNA is defective at the non-permissive temperature. Temperature-sensitivity for growth is recessive and segregates 2:2. The wild type gene, termed RIC1 (for ribosome control) was cloned by complementation of the temperature-sensitive phenotype from a genomic DNA library based on the CEN plasmid. RIC1 encodes a protein of 1056 amino acid (aa) residues including a putative nuclear localization sequence. Data base searches revealed that RIC1 is a novel gene and predicted aa sequence share some sequence similarity with viral transcriptional regulatory proteins.

Effects of exposure to hypobaric-hypoxia on body weight, muscular and hematological characteristics, and work performance in rats

The metabolic activities of skeletal muscles were studied in male rats exposed to hypobaric-hypoxia at about 550 Torr for 8 h per day for 2 weeks. Rats were divided into three groups; control (normoxic control), diurnal hypoxic (DH) exposure, and nocturnal hypoxic (NH) exposure groups. The changes in body weight and daily diet intake of the NH group were lower than the other groups (p < 0.01). The weights of fat in the abdominal cavity of both NH and DH groups were less than that of the control group. The red blood cell count, hemoglobin concentration, and hematocrit values were significantly increased in the hypoxic groups. The plasma glucose level in the NH group was significantly less than the control group (p < 0.05). The lactate dehydrogenase/citrate synthase (LDH/CS) activity ratios in the skeletal muscle tended to be lower in both hypoxic groups than in the control group. The swimming times to exhaustion at mild and high intensities that were measured after 2 weeks, loaded with a weight equivalent to 2.5% of the body weight, improved in the DH group. There were insignificant differences in the metabolic activity of skeletal muscles and blood characteristics between the NH and DH groups, but endurance swimming times in the DH group tended to be improved as compared to the NH group. We conclude that the DH group became competent in endurance work, which is believed to be driven from the combined effects of increased O2 transport capacity of the blood and enhanced O2 utilization capability by mitochondrial enzyme activity.

Further observations on cystic dilatation of the intrahepatic biliary system in biliary atresia after hepatic portoenterostomy: report on 10 cases

This is a report on ten patients with cystic dilatation of the intrahepatic biliary system (CDIB) after hepatic portoenterostomy. They were five girls and five boys and the diagnosis of CDIB was made at ages 6 months to 11 years (mean age: 2.8 +/- 3.3 years). Follow-up ranged from one month to 15 years (mean: 5.5 +/- 4.9 years). In order to elucidate the factors which affect the clinical outcome of such patients, the types of CDIB (Type A: noncommunicating solitary cyst, Type B: communicating solitary cyst, Type C: multi-cystic dilatation), clinical symptoms at onset of CDIB and the method for the treatment were reviewed in relation to the outcome. For the purpose of understanding pathogenesis of CDIB, immunohistochemical study on hepatobiliary system was done with monoclonal antibody for cytokeratin. Outcome of the patients of Type C was poor, whereas the outcome of patients with type A and B was good. The outcome of preoperatively jaundiced patients was poor, but jaundice-free patients showed good outcome. Method of treatment was not related to the outcome. As epithelium of CDIB was positive for monoclonal antibody of cytokeratin, it was suspected that pathogenesis of CDIB might be related to peribiliary gland which originated from ductal plate.

Ultrastructural findings of the macula utriculi in a case of a petrous apex cholesteatoma: a comparison with findings in a patient with an acoustic neuroma

The morphological characteristics of the vestibular sensory cells of the macula utriculi obtained during surgery in a patient with a petrous apex cholesteatoma were examined using scanning and transmission electron microscopy. Findings were compared to cells studied in a patient with acoustic neuroma. Scanning electron microscopy showed that compared to the apparently normal cells in the acoustic neuroma case, most sensory cells in the cholesteatoma case had large cuticular plates, irregular locations of cilia and no clear polarizations. Supporting cells showed profuse short microvilli on the whole surface. With transmission electron photomicrographs, type I hair cells were not seen and certain morphological changes were observed in type-II-like cells and supporting cells. We presume that the degenerative changes in the vestibular epithelia were due to circulatory disturbances and/or direct pressure applied to the vestibular nerve at the internal auditory canal, with subsequent involvement of the macula utriculi.

[Associated complication of biliary atresia: cystic dilatation of intrahepatic biliary system]

Cystic dilatation of intrahepatic biliary system (CDIB) was observed on 10 postoperative patients with biliary atresia (BA). Fever, jaundice and alcoholic stool were found when CDIB was diagnosed with ultrasonography and computed tomography assertained by cholangiography. CDIB was divided into three groups by the shape of intrahepatic biliary system. They were group A (n = 3); solitary non-communicating cyst, group B (n = 1); solitary communicating cyst and group C (n = 6); multi-cystic dilatation. Treatments of CDIB were percutaneous transhepatic bile drainage (PTBD) and reanastomosis of hepatic portoenterostomy. All of our patients of group A and B were doing well after PTBD in two and re-do Kasai operation in two. However, out of 6 patients of group C, two died without any treatments, three were transplanted liver from their parents and the rest one is still in the hospital and PTBD is continued. Outcome of CDIB is good in group A and B, and poor in group C.

Evidence for the involvement of NMDA receptors in vestibular compensation

The involvement of NMDA (N-methyl-D-aspartic acid) receptors in the initial stage of the vestibular compensation was evaluated by examining the effect of MK-801 on this compensation in guinea pigs. MK-801, injected 30 min before induction of unilateral labyrinthectomy by an arsanilate, significantly (P < 0.05) reduced the maximum frequency of the spontaneous nystagmus (SN) towards both the arsanilate-applied and the intact sides. In addition, injection of arsanilate into the opposite middle ear, 60 days subsequent to induction of the unilateral labyrinthectomy, suppressed the SN towards the second injected side, but had no effect on the SN towards the first injected side. These results suggest that NMDA receptors may be linked to the initiation of the vestibular compensation.

Ultrastructural localization of G-protein GS in the lateral wall of the guinea pig cochlear duct

Immunocytochemical localization of a GTP-binding protein, Gs, in the various cells of the lateral wall of guinea pig cochlear duct was investigated using a post-embedding immunogold method with antibody raised against a synthetic decapeptide (RMHLRQYELL) encoding the C-terminus of the alpha-subunit of Gs. In the stria vascularis, labeling was observed on the basolateral membrane infoldings of marginal cells, on the juxtaposed membrane of intermediate cells, and on the cell membrane of basal cell. In contrast, no significant labeling was observed on the luminal membrane of marginal cells. Immunoreactivity also was detected on the cell membranes of various other cells. These include spiral prominence epithelial cells, fibrocytes of spiral ligament, external sulcus cells, and epithelial and mesothelial cells of Reissner's membrane. Adenylylcyclase has been functionally implicated in some of the cell types with membranes labeled in this study. The significance of these findings is briefly discussed.

Ultrastructural localization of G-protein Gs in the organ of Corti

Immunocytochemical localization of a stimulatory GTP-binding protein Gs in the organ of Corti in the inner ear was examined with a post-embedding immunogold technique, using antibodies raised against a synthetic decapeptide (RMHLRQYELL) of the C-terminus of the alpha subunit of Gs. Immunoreactivity was strong on the membranes of supporting cells in the reticular lamina, including inner and outer pillar cells and the phalangeal process of Deiters' cells. Immunolabeling also was seen on the membranes of cell bodies of those cells which surround nerve fibers, basilar fibers, outer spiral fibers and afferent nerve endings at outer hair cells. Gold particles also labeled the membrane of inner phalangeal cells and border cells. In contrast, outer and inner hair cells were not labeled. Possible roles of Gs in the organ of Corti are discussed.