Correlation between DJ-1 levels in the cerebrospinal fluid and the progression of disabilities in multiple sclerosis patients

Objectives

DJ-1 plays a key role in the anti-oxidative stress function. Increasing evidence supports the role of oxidative stress in the pathogenesis of multiple sclerosis (MS). The aim of this study was to investigate whether the DJ-1 levels were increased in patients with MS and to examine its association with the progression of MS.

Methods

Quantitative immunoblot assays were performed to evaluate the DJ-1 level in serum and cerebrospinal fluid (CSF) collected from relapsing–remitting patients with MS ( n = 29), disease controls subjects ( n = 14), and healthy subjects ( n = 44).

Results

No significant difference was observed in the serum DJ-1 level among the patients with MS, disease controls, and healthy controls. However, the CSF DJ-1 levels were significantly higher in the patients with MS than in the disease control subjects ( P < 0.0001). A significant positive correlation was also found between the CSF DJ-1 levels and the Multiple Sclerosis Severity Score ( P < 0.005, r = 0.501).

Conclusions

These results show that the CSF DJ-1 levels are significantly increased in the CSF of patients with MS and that the CSF DJ-1 levels may be associated with the disease progression of MS. Therefore, DJ-1 possibly plays an important role in the pathogenesis of MS.

Caspase-mediated changes in histone H1 in early apoptosis: prolonged caspase activation in developing olfactory sensory neurons

Programmed cell death or apoptosis is required for the patterning and development of multicellular organisms. However, apoptosis is a difficult process to measure because the dead cells are rapidly degraded by their neighbors within a few hours. The post-caspase activation events that determine whether a cell will undergo apoptosis remain elusive. Here we report that apoptosis-specific nuclear events that occur before DNA fragmentation can be distinguished by monitoring the histone H1 status. In both mammals and Drosophila, dying cells failed to be immunolabeled with an anti-H1 monoclonal antibody, AE-4. Real-time imaging of caspase activation and H1 dynamics in mammalian neural cells revealed that H1 changed its location in the nucleus after caspase activation. In addition, the timing of this re-localization was largely dependent on the apoptotic stimulus used. From the staining patterns of AE-4 and anti-active caspase-3 antibodies, cells undergoing the transition from caspase activation to the apoptotic H1 change could be identified as H1-positive caspase-activated cells, providing a novel criterion for early apoptosis and making it possible to characterize caspase-activated cells in tissues. On the basis of these staining patterns, we found that many olfactory sensory neurons in the developing mouse olfactory epithelium showed sustained caspase activity without the H1 change, suggesting a unique caspase function in these neurons.

Molecular and biological characterization of histidine triad protein in group A streptococci

Four Streptococcus pneumoniae genes, phtA, phtB, phtD, and phtE, as well as the slr gene of group A streptococci (GAS), encode proteins with a histidine triad motif (HxxHxH). Pht proteins function as protective antigens against S. pneumoniae infection. A search of the GAS genome database identified a novel protein, HtpA, possessing five histidine triad motifs. The htpA gene was shown to encode a 92.5-kDa protein located downstream of the fbaA and lbp genes, while Western blot analyses revealed that HtpA protein was expressed on the cell surfaces of all group A, B, C, and G streptococcal isolates tested. Immunization of mice with rHtpA induced antigen-specific antibody production and was effective after a single immunization, with antibody titers remaining constant for at least 84days. In addition, HtpA-immunized mice survived after challenge with GAS strains isolated from patients with streptococcal toxic shock syndrome for significantly longer periods than sham-immunized mice. In that experiment, the HtpA-specific antibody was effectively induced by a single immunization and the specific antibody titer remained constant for at least 84days. These results indicate that the novel histidine triad protein HtpA is a candidate vaccine for GAS infection.

Streptococcus mutans clonal variation revealed by multilocus sequence typing

Streptococcus mutans is the major pathogen of dental caries, a biofilm-dependent infectious disease, and occasionally causes infective endocarditis. S. mutans strains have been classified into four serotypes (c, e, f, and k). However, little is known about the S. mutans population, including the clonal relationships among strains of S. mutans, in relation to the particular clones that cause systemic diseases. To address this issue, we have developed a multilocus sequence typing (MLST) scheme for S. mutans. Eight housekeeping gene fragments were sequenced from each of 102 S. mutans isolates collected from the four serotypes in Japan and Finland. Between 14 and 23 alleles per locus were identified, allowing us theoretically to distinguish more than 1.2 x 10(10) sequence types. We identified 92 sequence types in these 102 isolates, indicating that S. mutans contains a diverse population. Whereas serotype c strains were widely distributed in the dendrogram, serotype e, f, and k strains were differentiated into clonal complexes. Therefore, we conclude that the ancestral strain of S. mutans was serotype c. No geographic specificity was identified. However, the distribution of the collagen-binding protein gene (cnm) and direct evidence of mother-to-child transmission were clearly evident. In conclusion, the superior discriminatory capacity of this MLST scheme for S. mutans may have important practical implications.

Development of leiomyosarcoma of the uterus in MMTV-CR-1 transgenic mice

Overexpression of Cripto-1 (CR-1) in FVB/N mice using the MMTV-LTR promoter results in increased mammary tumourigenesis in these female transgenic mice (MMTV-CR-1). Here, we characterize uterine tumours that developed in 15/76 (19.7%) of MMTV-CR-1 female nulliparous or multiparous mice during 24 months of observation compared with 0/33 (0%) of FVB/N normal control mice observed during the same time period (p < 0.01). The uterine tumours collected from the MMTV-CR-1 mice were classified as leiomyosarcomas and found to express the CR-1 transgene by polymerase chain reaction analysis and immunohistochemistry. Detection by western blot analysis showed higher levels of phosphorylated (P) forms of c-src, Akt, GSK-3beta, and dephosphorylated (DP)-beta-catenin in lysates from MMTV-CR-1 uterine leiomyosarcomas in comparison with lysates from normal control FVB/N uteri. Immunostaining showed increased nuclear localization of beta-catenin in the MMTV-CR-1 uterine leiomyosarcomas. Increased immunostaining for CR-1 was detected in 9/13 (69.2%) cases of human leiomyosarcoma compared with staining in 3/15 (20%) human leiomyoma sections. Stronger immunostaining for P-src, P-Akt, P-GSK-3beta and increased nuclear localization of beta-catenin was also seen in human leiomyosarcomas in comparison with leiomyomas. Normal human uterine smooth muscle (UtSM) cells treated with exogenous soluble rhCR-1 showed increased levels of P-src, P-Akt, P-GSK-3beta and dephosphorylated (DP)-beta-catenin and increased proliferation (p < 0.05) and migration (p < 0.01) in comparison with untreated control UtSM cells. Inhibitors against c-src, Akt or beta-catenin, individually or in combination, significantly reduced CR-1-induced migration. These results suggest a role for CR-1 during uterine tumourigenesis either directly by activating c-src and Akt and/or via cross-talk with the canonical Wnt signalling pathway, as suggested by the increased expression of P-GSK-3beta, DP-beta-catenin, and increased nuclear localization of beta-catenin in human and MMTV-CR-1 mice leiomyosarcomas.

Distribution of Genotypes of Porphyromonas gingivalis in Type 2 Diabetic Patients with Periodontitis in Mexico

OBJECTIVE

To determine and compare the distribution of Porphyromonas gingivalis fimA genotypes in type 2 diabetes mellitus (T2DM) patients affected by periodontitis, using non-diabetic subjects with and without periodontitis as control groups.

MATERIAL AND METHODS

This study involved 75 subjects divided into three groups of 25 subjects each: Group 1 (non-T2DM without periodontitis), Group 2 (non-T2DM with periodontitis) and Group 3 (T2DM with periodontitis). The outcome variable was periodontitis, and explanatory variables were age, sex, T2DM and specific P. gingivalis fimA genotypes.

RESULTS

In non-T2DM subjects with healthy periodontal tissues, type I fimA was the most frequently detected individually (40%) or in combinations (40%). In non-T2DM subjects with periodontitis, the most frequently detected type was Ib individually (20%) or in combinations (36%). In T2DM patients with periodontitis, the most frequently detected types were types I (20%) and III (20%), but there was no statistical difference (p>0.05) with non-T2DM periodontitis subjects.

CONCLUSIONS

Type I genotype was more frequently detected in periodontally healthy sites from non-T2DM subjects than in periodontitis sites from either subjects with or without T2DM. However, in sites affected by periodontitis from T2DM subjects the predominating types were I and III, which are less virulent strains of P. gingivalis.

Screening for age-related macular degeneration using nonstereo digital fundus photographs

Age-related macular degeneration (AMD) is a disease with significant visual morbidity and accounts for the majority of blind registrations in the developed world including the UK. Certain forms of neovascular AMD are amenable to treatment but require expeditious referral to a retinal specialist.

AIM

To evaluate the possibility of using nonstereo fundus photographs as a low-cost screening tool for neovascular AMD.

DESIGN

Retrospective review of patients referred to the macular clinic of a teaching hospital in London.

METHODS

A total of 198 randomised digital fundus photographs, without any other clinical information, were presented to two independent ophthalmic interns who graded them into one of the three categories: normal, age-related maculopathy (ARM), or neovascular age-related macular degeneration (AMD) to determine the urgency of referral to clinic. The results were compared with the known diagnosis for each patient and sensitivities and specificities for each diagnostic category calculated.

RESULTS

The intraobserver Kappa statistic was 0.75 and 0.91 for grader 1 and 2, respectively. The interobserver Kappa was 0.54. The mean sensitivity and specificity for the identification of ARM was 60.5 and 76.3%, respectively The mean sensitivity and specificity for the identification of AMD was 85.7 and 78.8%, respectively.

CONCLUSION

Nonstereo digital fundus photograph is a reasonable screening tool for CNV and may aid in decreasing the visual morbidity it causes by enabling timely referrals and treatment.

Role of Streptococcus sanguinis sortase A in bacterial colonization

Streptococcus sanguinis, a normal inhabitant of the human oral cavity, has low cariogenicity, though colonization on tooth surfaces by this bacterium initiates aggregation by other oral bacteria and maturation of dental plaque. Additionally, S. sanguinis is frequently isolated from infective endocarditis patients. We investigated the functions of sortase A (SrtA), which cleaves LPXTG-containing proteins and anchors them to the bacterial cell wall, as a possible virulence factor of S. sanguinis. We identified the srtA gene of S. sanguinis by searching a homologous gene of Streptococcus mutans in genome databases. Next, we constructed an srtA-deficient mutant strain of S. sanguinis by insertional inactivation and compared it to the wild type strain. In the case of the mutant strain, some surface proteins could not anchor to the cell wall and were partially released into the culture supernatant. Furthermore, adherence to saliva-coated hydroxyapatite beads and polystyrene plates, as well as adherence to and invasion of human epithelial cells were reduced significantly in the srtA-deficient strain when compared to the wild type. In addition, antiopsonization levels and bacterial survival of the srtA-deficient mutant were decreased in human whole blood. This is the first known study to report that SrtA contributes to antiopsonization in streptococci. Our results suggest that SrtA anchors surface adhesins as well as some proteins that function as antiopsonic molecules as a means of evading the human immune system. Furthermore, they demonstrate that SrtA of S. sanguinis plays important roles in bacterial colonization.

Inhibitory Effects of Tumor Necrosis Factor-Alpha on Migration of Human Periodontal Ligament Cells

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) is associated with chronic gingival inflammation and is suspected to influence periodontal destruction. However, the exact roles of TNF-alpha in wound healing and periodontal tissue regeneration are largely unknown. In the present study, we examined the effects of TNF-alpha on migration and proliferation of human periodontal ligament (PDL) cells.

METHODS

PDL cells were cultured in the presence of TNF-alpha to determine its effects on cellular migration and proliferation. The protein expression profiles of alpha5 and beta1 integrin subunits and their related molecules, paxillin and focal adhesion kinases (FAK), were investigated. Gene expression of fibronectin also was assayed. Further, the activation of Rho-family small guanosine triphosphate (GTP)-binding protein (RhoA) was evaluated using a GTP-loading pull-down assay, and focal adhesion formation by PDL cells after transfection with the expression vector of paxillin-fused green fluorescent protein (GFP) also was observed with confocal microscopy.

RESULTS

Cellular migration was impaired by TNF-alpha and recovered following the addition of anti-TNF-alpha antibodies. In contrast, PDL cell proliferation was not affected by TNF-alpha. TNF-alpha upregulated the expression of the alpha5 and beta1 integrin subunits, whereas fibronectin was not overexpressed. Phosphorylation of paxillin and FAK by PDL cells was induced, and RhoA activation also was induced. Confocal microscopic analysis revealed that TNF-alpha induced focal adhesion and stress fiber formation in all parts of the cells.

CONCLUSION

Our results suggested that TNF-alpha impairs cellular migration by enhancing cellular adhesive ability following significant focal adhesion and stress fiber formation.

Multifunctional glyceraldehyde-3-phosphate dehydrogenase of Streptococcus pyogenes is essential for evasion from neutrophils

Streptococcus pyogenes is an important pathogen that causes pharyngitis, sepsis, and rheumatic fever. Cell-associated streptococcal C5a peptidase (ScpA) protects S. pyogenes from phagocytosis and has been suggested to interrupt host defenses by enzymatically cleaving complement C5a, a major factor in the accumulation of neutrophils at sites of infection. How S. pyogenes recognizes and binds to C5a, however, is unclear. We detected a C5a-binding protein in 8 M urea extracts of S. pyogenes by ligand blotting using biotinylated C5a. Searching of genome databases showed that the C5a-binding protein is identical to the streptococcal plasmin receptor (Plr), also known as streptococcal surface dehydrogenase (SDH) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In the present study we identified a novel function of this multifunctional protein. Western blotting and immunofluorescence microscopy with anti-Plr/SDH/GAPDH showed that Plr/SDH/GAPDH is located on the bacterial surface and released into the culture supernatant. Next, we examined whether the streptococcal Plr/SDH/GAPDH inhibits the biological effects of C5a on human neutrophils. We found that soluble Plr/SDH/GAPDH inhibits C5a-activated chemotaxis and H2O2 production. Furthermore, our results suggested that soluble Plr/SDH/GAPDH captures C5a, inhibiting its chemotactic function. Also, cell-associated Plr/SDH/GAPDH and ScpA were both necessary for the cleavage of C5a on the bacterial surface. Together, these results indicate that the multifunctional protein Plr/SDH/GAPDH has additional functions that help S. pyogenes escape detection by the host immune system.

Protective immunity against Streptococcus pyogenes challenge in mice after immunization with fibronectin-binding protein

BACKGROUND

Surface-associated fibronectin (Fn)-binding proteins of Streptococcus pyogenes play an important role in the bacterial invasion of epithelial cells. We examined the functional domain and protective antigenicity of the Fn-binding protein FbaA.

METHODS

To investigate the functional domain of FbaA and its localization on S. pyogenes, a series of recombinant glutathione S-transferase (GST)-truncated FbaA proteins was used for immunofluorescent microscopy, ligand blotting, and Biacore analyses. Mice were immunized with the truncated proteins for the determination of the immunogenic domains that contribute to protection against S. pyogenes infection.

RESULTS

Ligand-blotting and Biacore analyses revealed that the FbaA fragments harboring a proline-rich repeat domain (RD), but not the N- and C-terminal regions, possessed Fn-binding activity. Immunofluorescent microscopy findings showed that the N terminus and RD were exposed to external regions, which suggests that the RD serves as a Fn-binding element on live organisms. Specific antibodies were efficiently induced in N terminus- and RD-immunized mice and demonstrated bactericidal activity against S. pyogenes in vitro. FbaA-immunized mice survived significantly longer than GST-immunized mice after infection with serotype M1 and M49 strains expressing FbaA.

CONCLUSION

The Fn-binding RD and N terminus of FbaA are potential vaccine candidates for M1 strains of S. pyogenes infection.

Tear film lipid layer thickness and ocular comfort after meibomian therapy via latent heat with a novel device in normal subjects

AIM

This study measures changes in tear film lipid layer thickness (LLT) and ocular comfort in normal subjects after 10 min use of a novel device, which delivers meibomian therapy with latent heat. The device is designed to promote the release of meibomian sebum into the tear film by delivering latent heat to the eyelids, thus thickening the lipid layer. Normal lid movements are maintained, facilitating resurfacing of the tear film.

METHOD

A prospective, controlled, observer masked, single intervention trial in which 24 normal subjects were randomised into three groups. Group I underwent 10 min treatment with the activated device, Group II used the inactivated device for the same duration of time, and Group III had no intervention. The LLT of each subject was measured with a Keeler Tearscope prior and subsequent to the 10-min period. Subjective alteration in ocular comfort was also assessed.

RESULTS

Seven of eight subjects (87.5%) in Group I exhibited an increase in LLT. The mean LLT in this group showed a statistically significant increase (left eyes 1.0 levels, P<0.001, right eyes 0.9 levels, P<0.003) compared to Groups II and III. Six of eight subjects (75%) using the activated device experienced subjective improvement in ocular comfort.

CONCLUSION

Meibomian therapy with this device increases LLT in normal individuals. This implies a more stable tear film, reflected in subjective improvement in ocular comfort.

Eyelid basal cell carcinoma: non-Mohs excision, repair, and outcome

AIM

To analyse the outcome of basal cell carcinoma (BCC) excision in a subregional (non-Mohs) oculoplastic service.

METHODS

A single surgeon retrospective series, medical record review of 223 consecutive cases with histologically confirmed eyelid BCC (between 1987 and 2004). Tumour recurrence rate was derived from the 69 patients with a minimum 5 year follow up.

RESULTS

Of the total 223 patients, the surviving 162 were included in this study. The follow up for the whole cohort ranged from 2 months to 120 months. All cases underwent excisional biopsy. 4 mm excision margins were taken in 83% of cases. The pathology revealed 84% complete primary excision. Of those reported incompletely excised 53% contained no tumour at re-excision. 70% of lid defects were treated by primary direct closure. Following confirmed histological clearance the remainder underwent delayed direct closure (2%), full thickness skin or tarsal grafts (13%), local skin and muscle flaps (11%), and spontaneous granulation (laissez faire) (4%). No major complications were noted. There were no recurrences for non-infiltrative BCCs. The overall 5 year and over recurrence rate including previously recurrent BCCs was 4.35%, only one of which was in the primary BCC group (1.6%). All recurrences were in infiltrative BCCs.

CONCLUSIONS

Non-infiltrative BCC excision with 4 mm margins gave a zero recurrence rate. Long term follow up of such patients may be unnecessary. Infiltrative BCCs should be followed up indefinitely. Previous recurrence and infiltrative histology have predictive value for recurrence. We achieved one of the lowest recurrence rates reported in non-Mohs surgical excision. Direct closure was applicable in 72% of cases.

Pulmonary alveolar microlithiasis: CT and pathologic findings in 10 patients

BACKGROUND AND AIM

To evaluate CT findings of pulmonary alveolar microlithiasis and correlate the CT with the pathologic findings.

METHODS

The study included 10 patients with pathologically proven microlithiasis. Two independent observers evaluated the presence, extent and distribution of the CT findings. CT findings were compared with those at autopsy in two patients and with transbronchial biopsy in eight patients.

RESULTS

All patients had a myriad of calcified nodules measuring approximately 1 mm in diameter. Close apposition of the nodules resulted in areas of ground-glass attenuation and consolidation, which were the predominant abnormality on CT in all 10 patients, involving 41% +/- 16.3 (mean +/- SD) and 30% +/- 4.8 of the lung parenchyma, respectively. Calcifications were also seen along interlobular septa, bronchovascular bundles and pleura. Other findings included interlobular septal thickening, thickening of bronchovascular bundles, nodules, and subpleural cysts. There was a solid agreement between the observers for the presence (kappa value; 0.77) and extent (Spearman rank correlation; r = 0.81 to 1.0 p < 0.01) of abnormalities. Autopsy specimens demonstrated microliths in alveolar airspaces and along interlobular septa, bronchovascular bundles and pleura. Subpleural small cysts were shown to represent dilated alveolar ducts.

CONCLUSION

Pulmonary microlithiasis is characterised by the presence of numerous small, calcified nodules, calcifications along interlobular septa, bronchovascular bundles and pleura, ground-glass opacities, consolidation, and subpleural cysts. The cysts represent dilated alveolar ducts.

Systemic immunization with streptococcal immunoglobulin-binding protein Sib35 induces protective immunity against group A Streptococcus challenge in mice

The streptococcal immunoglobulin (Ig)-binding protein Sib 35 binds to IgG, IgM and IgA in human, mouse and bovine. Since all group A Streptococcus pyogenes (GAS) strains examined express the sib 35 gene, we evaluated the Sib 35 as a vaccine candidate against GAS infections. We detected significantly higher anti-Sib 35 IgG antibody titers in sera from patients with GAS infections than from healthy volunteers. Immunization of mice with Sib 35 induced antigen-specific IgG antibodies in their sera, and rabbit Sib 35-specific antiserum showed opsonic activity. Immunization with Sib 35 enhanced survival rates in mice challenged with a GAS strain, while exhibiting no toxicity in hosts. We conclude that Sib 35 is a promising vaccine for prevention of GAS infections.

Unrelated donor bone marrow transplantation for 100 pediatric patients: a single institute's experience

In all, 100 unrelated donor bone marrow transplantations (UD-BMT) were performed in our institute between October 1993 and January 2003. Of 93 evaluable patients, 73 patients had hematological malignancy, 13 had nonmalignancy and seven had lymphoproliferative disease. The estimated 9-year event-free survival (EFS) rate was 57.1+/-5.5% in all patients. In the following analyses of the patients with hematological malignancy, the standard group had significantly better EFS than the high-risk group (61.5+/-7.0 vs 35.6+/-9.7%, P=0.02), and the EFS rate of the tacrolimus (FK-506)+methotrexate (MTX)+/-methylprednisolone prophylactic group for graft-versus-host disease was superior to that of the FK-506 without MTX group (75.7+/-8.0 vs 55.8+/-7.6%, P=0.02). When we compared the EFS rates of the FK506+MTX+/-methylprednisolone (mPSL) group and the HLA-matched related donor BMT group in our institute, these were almost similar (75.7+/-8.1 vs 68.4+/-9.3%). Therefore, UD-BMT using FK-506+MTX+/-mPSL is a safe and useful method for children with hematological malignancy who require allogeneic BMT.

Role of Glucose Side Chains with Serotype-Specific Polysaccharide in the Cariogenicity of Streptococcus mutans

Previously, we isolated and characterized a new Streptococcus mutans strain (serotype k) from human blood and oral cavity samples, and found that the serological properties of serotype k strains were similar to those of a gluA-inactivated mutant strain of MT8148 (MT8148GD). MT8148GD showed significantly lower sucrose-dependent adhesion to glass surfaces, sucrose-independent adhesion to saliva-coated hydroxyapatite, dextran-binding activity, and cell-associated glucosyltransferase (GTF) activity than the parent strain. Further, Western blot analysis revealed reduced GTFB and GTFC expression in serotype k strains as compared to MT8148, though the caries-inducing activities of MT8148GD and a serotype k oral isolate in rats were similar to that of MT8148. We conclude that a glucose side-chain defect in the serotype-specific polysaccharide of S. mutans may be associated with its cariogenicity, though to a lesser extent than its other major surface proteins.

Effect of CYP2C19 polymorphism on the safety and efficacy of omeprazole in Japanese patients with recurrent reflux oesophagitis

BACKGROUND

The polymorphic enzyme cytochrome P450 2C19 affects omeprazole metabolism. This influence on metabolism might affect serum gastrin levels, and safety, during long-term treatment of reflux oesophagitis.

AIM

To examine the relationship between cytochrome P450 2C19 genotype and the safety profile of long-term omeprazole treatment.

METHODS

A total of 119 Japanese patients with recurrent reflux oesophagitis underwent cytochrome P450 2C19 genotyping prior to receiving daily omeprazole 10 mg or 20 mg for 6-12 months, during which adverse event frequency, serum gastrin levels and endoscopic findings were monitored.

RESULTS

The incidences of adverse events, serious adverse events and adverse events leading to withdrawal did not differ between homozygous extensive metabolizer (n = 46), heterozygous extensive metabolizer (n = 53) or poor metabolizer (n = 20) groups. In all genotype groups, serum gastrin increased during the first 3 months of dosing but stabilized thereafter. No significant differences were seen either in the rate of reflux oesophagitis healing or symptom improvement among genotype groups.

CONCLUSIONS

Long-term treatment with omeprazole was well-tolerated in Japanese patients, irrespective of their cytochrome P450 2C19 metabolic genotype, indicating that dose adjustment depending on metabolic genotype is not required during treatment with omeprazole.

Sparse and wavy hair: a new model for hypoplasia of hair follicle and mammary glands on rat chromosome 17

Mutant animals in the skin and hair have been used to identify important genes in biomedical research. We describe a new mutant rat, sparse and wavy hair (swh), that spontaneously arose in a colony of inbred WTC rats. The mutant phenotype was characterized by sparse and wavy hair, which was most prominent at age 3-4 weeks, and was inherited in an autosomal recessive manner. The swh/swh rats showed impaired gain of body weight, and their hair follicles were reduced both in number and size, associated with hypoplasia of the sebaceous glands and the subcutaneous fat tissue. Female swh/swh rats were unable to suckle their offspring. Their mammary glands were hypoplastic, and differentiation of mammary epithelial and myoepithelial cells was impaired. Linkage analysis of 579 backcross rats localized the swh locus to a .35-cM region between D17Rat131 and D17Rat50 in the distal end of rat Chr 17. The swh locus spanned the 3.7-Mb genomic region where 24 genes have been mapped and corresponded to the centromere region of the mouse Chr 2 or the region of the human Chr 10p11.1-p14. None of the genes or loci described in mouse or human hair and skin diseases mapped to these regions. These findings suggest that the rat swh is a novel mutation associated with impaired development of the skin appendages, such as hair follicles, sebaceous glands, and mammary glands, and will provide an experimental model to clarify a gene and mechanisms for development of skin appendages.

Silkworm pathogenic bacteria infection model for identification of novel virulence genes

Silkworms are killed by injection of pathogenic bacteria, such as Staphylococcus aureus and Streptococcus pyogenes, into the haemolymph. Gene disruption mutants of S. aureus whose open reading frames were previously uncharacterized and that are conserved among bacteria were examined for their virulence in silkworms. Of these 100 genes, three genes named cvfA, cvfB, and cvfC were required for full virulence of S. aureus in silkworms. Haemolysin production was decreased in these mutants. The cvfA and cvfC mutants also had attenuated virulence in mice. S. pyogenes cvfA-disrupted mutants produced less exotoxin and had attenuated virulence in both silkworms and mice. These results indicate that the silkworm-infection model is useful for identifying bacterial virulence genes.