Androgen Regulates Gene Expression of Cytoskeletal Proteins in Adult Rat Motoneurons

Expression of β-actin and β-tubulin mRNA was examined in androgen-sensitive motoneurons of the spinal nucleus of the bulbocavernosus (SNB) in adult male rats by in situ hybridization histochemistry using complementary DNAs encoding chick β-actin and mouse β-tubulin, respectively. Both hybridizable β-actin and βtubulin mRNAs were localized in the somata and proximal dendrites of SNB motoneurons. Removal of androgen by castration significantly reduced the expression levels of both β-actin and β-tubulin mRNAs in the SNB motoneurons, whereas the changes were prevented by testosterone treatment. In contrast, castration or testosterone treatment induced little or no change in the expression levels of these mRNAs in the much less androgen-sensitive motoneurons of the retrodorsolateral nucleus (RDLN). These results suggest that androgen regulates the expression of β-actin and β-tubulin genes in the SNB motoneurons and may provide evidence for the molecular mechanisms of hormonally induced neuronal plasticity in the SNB motoneurons.     

Rhegmatogenous retinal detachment in a patient with choroidal melanoma simulating choroidal detachment: a case report

Background

Ophthalmologists and retina specialists may consider choroidal detachment if patients with rhegmatogenous retinal detachment present with choroidal elevation. That misdiagnosis may lead to inappropriate treatments, development of tumor cell dissemination, and eventual promotion of patient death. We report a case of a patient with rhegmatogenous retinal detachment associated with choroidal melanoma simulating choroidal detachment according to fundus findings.

Case presentation

A 78-year-old Japanese woman with blurred vision in her right eye was referred to our hospital because of rhegmatogenous retinal detachment with complicated atypical choroidal detachment. Her intraocular pressure was normal with clear anterior chamber. Retinal detachment involving the inferior and nasal retina was observed, and a retinal hole was noted in the same quadrant. A small yellowish choroidal elevation was located in the inferonasal site. Gadolinium-enhanced magnetic resonance imaging revealed enhancement corresponding to the elevation, leading to the identification of a choroidal tumor. Enucleation of the patient’s right eye was eventually performed. The enucleated eye histologically demonstrated malignant melanoma.

Conclusions

If hypotony or an inflammatory sign is absent, ophthalmologists should pay attention to the differential diagnosis of choroidal elevations observed in such patients.

     

Drug Resistance of Enteric Bacteria XIII. Distribution of R Factors in Escherichia coli Strains Isolated from Livestock

Escherichia coli strains isolated from 151 swine and 108 fowl, which were kept at the Animal Health Center, Maebashi, Japan, were surveyed for drug resistance and distribution of R factors. All of the swine and 38% of the fowl excreted E. coli strains resistant to tetracycline, chloramphenicol, streptomycin, and sulfanilamide, or certain combinations thereof. Among 278 resistant cultures isolated from swine, 13% were found to be resistant to one antibiotic, whereas 87% were resistant to more than one antibiotic. Among these resistant strains, 40% carried R factors which were transferable by the usual conjugal process. The resistance patterns of these R factors included 36% which were singly resistant and 64% which were multiply resistant. Among 54 resistant cultures isolated from fowl, 24% were singly resistant and 76% were multiply resistant. Of the resistant strains from fowl, 22% carried R factors. The resistance patterns of R factors included 50% of the singly resistant type and 50% which were multiply resistant. In spite of feeding with dairy products containing only tetracycline, a high incidence of multiple resistance was observed in the E. coli strains and the R factors isolated from these animals.     

Experimental Salmonellosis VIII. Postinfective Immunity and Its Significance for Conferring Cellular Immunity

In the process of live-vaccine immunization of Salmonella enteritidis infection in mice, the relation between the number of bacteria in the organs of mice and their protecting effect was studied. Treatment with antibiotics was used to control the number of immunizing bacteria in the tissues. Mice, which were infected with 10(-5) mg (1,000 mouse MLD) of virulent S. enteritidis and treated with kanamycin simultaneously, acquired high antilethal resistance against infection with the same organisms. However, the administration of large amounts of kanamycin, which caused a rapid decrease in bacterial numbers in the organs of infected mice, was incapable of conferring immunity. This indicated the necessity of persistence of live bacteria in the host for the production of immunity. A large number of microorganisms were maintained for 53 weeks in a diffusion chamber inserted into the mouse abdominal cavity. The mice implanted with diffusion chambers containing large numbers of virulent S. enteritidis did not acquire antilethal resistance against infection with the same organisms, although agglutinins against S. enteritidis were observed in these mice. Agglutinin was also found in the fluid contained in diffusion chambers inserted into mice immunized with a killed vaccine of S. enteritidis. This indicated that antibody penetrated the membrane filter of diffusion chambers from outside to inside and vice versa. From these results, it is suggested that contact of live microorganisms with the host cell is necessary for conferring postinfective immunity in salmonellosis.     

Evolution of restriction sites of ribosomal DNA in natural populations of the field mouse,Apodemus speciosus

An analysis by restriction endonuclease digestion of ribosomal DNA (rDNA) was carried out in natural populations of Apodemus speciosus, a field mouse that is endemic to Japan. Two restriction sites, the EcoRI (E3) and DraI (D4) sites, in the nontranscribed spacer region downstream from the gene for 28S RNA showed polymorphism within and between individuals in the populations from the Japanese main islands. By contrast, populations from the small adjoining islands which are thought to have separated from the main islands 1–2 × 10⁴ years ago showed relatively low levels of polymorphism within and between individuals, i.e., one of the polymorphic bands in the case of each enzyme was predominant in these populations, irrespective of the variants. These results indicate that the rate of fixation of site variations depends on population size and that the direction of fixation is random. Furthermore, each polymorphic restriction site seems to be fixed independently.Correspondence to: H. Suzuki     

The BIR and BIR-like domains of Bombyx mori nucleopolyhedrovirus IAP2 protein are required for efficient viral propagation

The baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV) possesses two genes, iap1 and iap2, which encode inhibitor of apoptosis (IAP) proteins. We previously showed that although both genes are dispensable for viral propagation, iap2 is required for efficient viral propagation in cultured cells. BmNPV IAP2 contains three putative functional domains: a baculovirus IAP repeat (BIR), a BIR-like (BIRL) domain, and a RING finger domain. To identify the domain affecting viral growth, we generated a series of BmNPV bacmids expressing iap2 derivatives lacking one or two domains, or possessing a single amino acid substitution to abolish IAP2 ubiquitin ligase activity. We examined their properties in both cultured cells and B. mori larvae. We found that either the BIR or BIRL domain of IAP2 plays an important role in BmNPV infection, and that the RING finger domain, which is required for ubiquitin ligase activity, does not greatly contribute to BmNPV propagation. This is the first study to identify functional domains of the baculovirus IAP2 protein.     

Long-term adaptation of the Bombyx mori BmN4 cell line to grow in serum-free culture

Bombyx mori ovary-derived BmN4 cells have been successfully adapted to a commercial serum-free medium (SFM; SF900-II) by gradually reducing the serum-containing TC-100 medium content from 100 to 0% (v/v). The BmN4 cells adapted to the SFM (BmN-SFM) adhered strongly to the culture flask and showed altered cell morphology. The BmN-SFM was subcultured 200 times, and the population doubling time was 4.70 d. Infection studies showed that BmN-SFM cells were easily susceptible to B. mori nucleopolyhedrovirus (BmNPV), and both the multiplication of budded virus and the promoter activity of the polyhedrin gene in BmN-SFM cells were almost the same as those in BmN4 cells before adaptation. Additionally, mouse interleukin-3 expressed by a recombinant BmNPV was normally secreted and modified with N-linked glycans in BmN-SFM cells. These findings indicate that BmN-SFM is particularly useful for a BmNPV-based baculovirus expression vector system with serum-free conditions.     

Presence of Neutrophil Extracellular Traps and Citrullinated Histone H3 in the Bloodstream of Critically Ill Patients

Neutrophil extracellular traps (NETs), a newly identified immune mechanism, are induced by inflammatory stimuli. Modification by citrullination of histone H3 is thought to be involved in the in vitro formation of NETs. The purposes of this study were to evaluate whether NETs and citrullinated histone H3 (Cit-H3) are present in the bloodstream of critically ill patients and to identify correlations with clinical and biological parameters. Blood samples were collected from intubated patients at the time of ICU admission from April to June 2011. To identify NETs, DNA and histone H3 were visualized simultaneously by immunofluorescence in blood smears. Cit-H3 was detected using a specific antibody. We assessed relationships of the presence of NETs and Cit-H3 with the existence of bacteria in tracheal aspirate, SIRS, diagnosis, WBC count, and concentrations of IL-8, TNF-α, cf-DNA, lactate, and HMGB1. Forty-nine patients were included. The median of age was 66.0 (IQR: 52.5–76.0) years. The diagnoses included trauma (7, 14.3%), infection (14, 28.6%), resuscitation from cardiopulmonary arrest (8, 16.3%), acute poisoning (4, 8.1%), heart disease (4, 8.1%), brain stroke (8, 16.3%), heat stroke (2, 4.1%), and others (2, 4.1%). We identified NETs in 5 patients and Cit-H3 in 11 patients. NETs and/or Cit-H3 were observed more frequently in “the presence of bacteria in tracheal aspirate” group (11/22, 50.0%) than in “the absence of bacteria in tracheal aspirate” group (4/27, 14.8%) (p<.01). Multiple logistic regression analysis showed that only the presence of bacteria in tracheal aspirate was significantly associated with the presence of NETs and/or Cit-H3. The presence of bacteria in tracheal aspirate may be one important factor associated with NET formation. NETs may play a pivotal role in the biological defense against the dissemination of pathogens from the respiratory tract to the bloodstream in potentially infected patients.