IRF2 maintains the stemness of colonic stem cells by limiting physiological stress from interferon

The physiological stresses that diminish tissue stem-cell characteristics remain largely unknown. We previously reported that type I interferon (IFN), which is essential for host antiviral responses, is a physiological stressor for hematopoietic stem cells (HSCs) and small intestinal stem cells (ISCs) and that interferon regulatory factor-2 (IRF2), which attenuates IFN signaling, maintains their stemness. Here, using a dextran sodium sulfate (DSS)-induced colitis model, we explore the role of IRF2 in maintaining colonic epithelial stem cells (CoSCs). In mice with a conditional Irf2 deletion in the intestinal epithelium (hereafter Irf2ΔIEC mice), both the number and the organoid-forming potential of CoSCs were markedly reduced. Consistent with this finding, the ability of Irf2ΔIEC mice to regenerate colon epithelium after inducing colitis was severely impaired, independently of microbial dysbiosis. Mechanistically, CoSCs differentiated prematurely into transit-amplifying (TA) cells in Irf2ΔIEC mice, which might explain their low CoSC counts. A similar phenotype was induced in wild-type mice by repeated injections of low doses of poly(I:C), which induces type I IFN. Collectively, we demonstrated that chronic IFN signaling physiologically stresses CoSCs. This study provides new insight into the development of colitis and molecular mechanisms that maintain functional CoSCs throughout life.

Regulated IFN signalling preserves the stemness of intestinal stem cells by restricting differentiation into secretory-cell lineages

Intestinal stem cells (ISCs) are located at the crypt base and fine-tune the balance of their self-renewal and differentiation^1,2, but the physiological mechanism involved in regulating that balance remains unknown. Here we describe a transcriptional regulator that preserves the stemness of ISCs by restricting their differentiation into secretory-cell lineages. Interferon regulatory factor 2 (IRF2) negatively regulates interferon signalling³, and mice completely lacking Irf2⁴ or with a selective Irf2 deletion in their intestinal epithelial cells have significantly fewer crypt Lgr5^hi ISCs than control mice. Although the integrity of intestinal epithelial cells was unimpaired at steady state in Irf2-deficient mice, regeneration of their intestinal epithelia after 5-fluorouracil-induced damage was severely impaired. Similarly, extended treatment with low-dose poly(I:C) or chronic infection of lymphocytic choriomeningitis virus clone 13 (LCMV C13)⁵ caused a functional decline of ISCs in wild-type mice. In contrast, massive accumulations of immature Paneth cells were found at the crypt base of Irf2^-/- as well as LCMV C13-infected wild-type mice, indicating that excess interferon signalling directs ISCs towards a secretory-cell fate. Collectively, our findings indicate that regulated interferon signalling preserves ISC stemness by restricting secretory-cell differentiation.

Flexible fate commitment of E2-2high common DC progenitors implies tuning in tissue microenvironments

The basic helix-loop-helix transcription factor E2-2 is essential for the development of plasmacytoid dendritic cells (pDCs) but not conventional DCs (cDCs). Here, we generated E2-2 reporter mice and demonstrated that an E2-2high fraction among common DC progenitors, which are a major source of pDCs and cDCs in the steady state, strictly gave rise to pDCs in the presence of Flt3 (Fms-like tyrosine kinase receptor-3) ligand ex vivo or in the secondary lymphoid organs when transferred in vivo. However, in the small intestine, some of these E2-2high progenitors differentiated into cDCs that produced retinoic acid. This transdifferentiation was driven by signaling via the common β receptor, a receptor for the cytokines IL-3, IL-5 and GM-CSF, which are abundant in the gut. In the presence of GM-CSF and Flt3 ligand, E2-2high-progenitor-derived cDCs consistently induced Foxp3+ Treg cells ex vivo. Our findings reveal the commitment and flexibility of E2-2high progenitor differentiation and imply that pertinent tuning machinery is present in the gut microenvironment.

Extracorporeal shock wave lithotripsy treatment of pancreatic stones complicated with advanced stage autoimmune pancreatitis

BACKGROUND

Although most patients with autoimmune pancreatitis (AIP) respond favorably to prednisolone therapy, some individuals who later suffer from pancreatic calculi may require additional extracorporeal shock wave lithotripsy (ESWL) treatment. This study compares the efficacy of ESWL for calculi in AIP with that in ordinary chronic pancreatitis (CP) and proposes a new treatment approach for pancreatic duct stones occurring in AIP.

METHODS

We examined the clinical records of 8 patients with chronic stage AIP and 92 patients with ordinary CP who received ESWL for pancreatic calculi.

RESULTS

The AIP group was significantly older than the CP group (69.0 vs. 56.5 years, P = 0.018). With regard to the indications for ESWL, chronic pain was significantly less frequent in the chronic stage AIP group (0% vs. 45.7%, P = 0.001), whereas preservation of pancreatic function was significantly more frequent (75% vs. 19.6%, P = 0.001). Compared with the CP group, the AIP group tended to exhibit pancreatic duct stenosis proximal to pancreatic calculi and had a lower rate of complete extraction of stones from the main pancreatic duct. Histopathological analysis of a patient with chronic stage AIP revealed widely distributed nodular pancreatitis, which was characteristic of ordinary CP, along with isolated areas of lymphoplasmacytic sclerosing pancreatitis.

CONCLUSIONS

Different approaches are needed for the treatment of pancreatic calculi in chronic stage AIP and ordinary CP. Specifically, it appears that intensive ESWL therapy can be avoided or delayed in AIP if the patient displays: (1) advanced age, (2) little or no chronic pain or pancreatitis, and (3) pancreatic duct stenosis proximal to pancreatic stones. In such cases, the benefit of ESWL treatment may be outweighed by the risks involved in this procedure.

Autoimmune pancreatitis can develop into chronic pancreatitis

Autoimmune pancreatitis (AIP) has been recognized as a distinct type of pancreatitis that is possibly caused by autoimmune mechanisms. AIP is characterized by high serum IgG4 and IgG4-positive plasma cell infiltration in affected pancreatic tissue. Acute phase AIP responds favorably to corticosteroid therapy and results in the amelioration of clinical findings. However, the long-term prognosis and outcome of AIP remain unclear. We have proposed a working hypothesis that AIP can develop into ordinary chronic pancreatitis resembling alcoholic pancreatitis over a long-term course based on several clinical findings, most notably frequent pancreatic stone formation. In this review article, we describe a series of study results to confirm our hypothesis and clarify that: 1) pancreatic calcification in AIP is closely associated with disease recurrence; 2) advanced stage AIP might have earlier been included in ordinary chronic pancreatitis; 3) approximately 40% of AIP patients experience pancreatic stone formation over a long-term course, for which a primary risk factor is narrowing of both Wirsung’s and Santorini’s ducts; and 4) nearly 20% of AIP patients progress to confirmed chronic pancreatitis according to the revised Japanese Clinical Diagnostic Criteria, with independent risk factors being pancreatic head swelling and non-narrowing of the pancreatic body duct.

Prominent role for plasmacytoid dendritic cells in mucosal T cell-independent IgA induction

Although both conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) are present in the gut-associated lymphoid tissues (GALT), the roles of pDCs in the gut remain largely unknown. Here we show a critical role for pDCs in T cell-independent (TI) IgA production by B cells in the GALT. When pDCs of the mesenteric lymph nodes (MLNs) and Peyer's patches (PPs) (which are representative GALT) were cultured with naive B cells to induce TI IgA class switch recombination (CSR), IgA production was substantially higher than in cocultures of these cells with cDCs. IgA production was dependent on APRIL and BAFF production by pDCs. Importantly, pDC expression of APRIL and BAFF was dependent on stromal cell-derived type I IFN signaling under steady-state conditions. Our findings provide insight into the molecular basis of pDC conditioning to induce mucosal TI IgA production, which may lead to improvements in vaccination strategies and treatment for mucosal-related disorders.

Nucleotide oligomerization binding domain-like receptor signaling enhances dendritic cell-mediated cross-priming in vivo

Nucleotide oligomerization binding domain (Nod)-like receptors are critical cytosolic sensors for the recognition of bacterial peptidoglycan. However, their role in the induction of dendritic cell (DC)-mediated cross-priming remains unclear. In this study, we demonstrate that injecting ligands for Nod1 and Nod2 along with Ag into wild-type mice significantly enhanced the cross-priming of Ag-specific CD8+ T cells by CD8alpha+ DCs, as assessed from the expansion of IFN-gamma+ CD8+ T cells, CTL activity against Ag-pulsed targets, and the rejection of transplanted tumors expressing the cognate Ag. The enhancement of CD8alpha+ DC-mediated cross-priming was likely due to the upregulation of Ag cross-presentation and of costimulatory molecules. Our findings collectively indicate that Nod1/2 signaling is critical for the optimal induction of DC cross-priming in vivo, which may offer an alternative therapeutic pathway in cancer and hosts refractory to TLR signals or paralyzed by viral evasion strategy.

Histone acetylation and steroid receptor coactivator expression during clofibrate-induced rat hepatocarcinogenesis

Peroxisome proliferators (PPs), non-genotoxic rodent carcinogens, cause the induction of the peroxisomal fatty acid beta-oxidation system, including bifunctional enzyme (BE) and 3-ketoacyl-CoA thiolase (TH), in the liver. GST M1 gene is polymorphic in Sprague-Dawley rats, NC- and KS-type. The KS-type rats showed enhanced susceptibility to ethyl-alpha-chlorophenoxyisobutyrate (clofibrate, CF), one of the PPs. The degree of BE induction was higher in the KS-type and preneoplastic foci developed after 6-8 weeks of treatment, whereas no foci developed in the NC-type. In the preset study, factors involved in different BE inducibility were investigated. There were no differences in hepatic peroxisome proliferator-activated receptor (PPAR) alpha levels between them. Among various coactivators for PPARalpha, only steroid receptor coactivator (SRC)-3 level was higher in the KS-type. To investigate the association between PPARalpha and SRC-3 or other proteins, nuclear extracts from CF-treated livers were applied to a PPARalpha column. In the KS-type, 110, 72, and 42 kDa proteins were bound and these were identified as SRC-3, BE, and TH, respectively. EMSA supported the binding of these proteins to PPARalpha associated to the BE enhancer in CF-treated KS-type, but not in the NC-type. Histone H3 acetylation was increased 11-fold in the KS-type by CF treatment but not in the NC-type. As BE and TH are responsible for acetyl-CoA production and SRC-3 possesses a histone acetyltransferase activity, these results suggest that enhanced BE induction in the KS-type livers is due to acetylation-mediated transcriptional activation and epigenetic mechanisms might be involved in CF-induced rat hepatocarcinogenesis.

Different susceptibility to peroxisome proliferator-induced hepatocarcinogenesis in rats with polymorphic glutathione transferase genes

Although peroxisomal bifunctional enzyme (enoyl-CoA hydratase/L-3-hydroxyacyl-CoA dehydrogenase; BE) is a positive marker for peroxisome proliferation, it is completely absent or expressed very weakly in rat hepatic preneoplastic and neoplastic lesions induced by peroxisome proliferators (PP). After administration of PP for 8-15 weeks, some rats exhibit BE-negative preneoplastic foci but other rats do not. In the present study, to investigate the involvement of glutathione S-transferase (GST) M1 gene polymorphism in interindividual differences in susceptibility to PP, we developed a method to determine the genotypes of rats. We then examined whether rats with one type encoding 198Asn-199Cys (NC-type) or another encoding 198Lys-199Ser (KS-type) exhibit differences in clofibrate (CF) susceptibility. After administration of 0.3% CF for 6 weeks or more, BE-negative foci were found immunohistochemically in KS/KS-type rats, but not in NC/NC-type rats. The number of BE-negative foci in KS/KS rats was 15.3 +/- 9.0 foci/cm2 of liver section after 6 weeks of CF administration, and the values did not alter thereafter. The mean areas of BE-negative foci in KS/KS rat livers increased during the period from 6 to 60 weeks. At weeks 30 and 60, almost all BE-negative foci exhibited a clear cell phenotype, a type of preneoplastic hepatic lesion. BE-negative foci were devoid of peroxisome proliferator-activated receptor alpha, whereas surrounding tissues were positive for the receptor. These results indicate that rats that are polymorphic for the GST M1 gene exhibit different susceptibilities to CF in vivo.

Nuclear localization of STAT5A modified with O-linked N-acetylglucosamine and early involution in the mammary gland of Hirosaki hairless rat

Hirosaki hairless rat (HHR) is a mutant strain spontaneously derived from Sprague-Dawley rats (SDR), and its inheritance is autosomal recessive. In addition to hair loss, female HHRs show involution of the mammary gland at an early stage of lactation. In the present study we investigated the mammary gland development in HHR. Morphological examinations revealed that HHR mammary glands are underdeveloped in virgins and exhibit distended alveoli on day 1 of lactation (L1), followed by involution. Milk secretion was observed on L1 in HHR. Whey acidic protein and other proteins were increased in milk of HHR and heterozygous rats on SDS-polyacrylamide gel electrophoresis. Terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay revealed apoptosis induction in HHRs at an early stage of lactation. By Western blotting, signal transducer and activator of transcription (STAT) 5A levels in cytoplasmic and nuclear fractions of the mammary glands were not different between HHR and SDR on L1 and L7. Nuclear localization of STAT5A in HHR and SDR was confirmed by immunohistochemistry. Tyr-phosphorylated STAT5A was not detected in HHR but was detected in SDR nuclear fractions. Several proteins modified with O-linked N-acetylglucosamine (O-GlcNAc) were detected in HHR nuclear extract on L1, although not in SDR or heterozygous rats by Western blotting. When HHR nuclear extract was applied to wheat germ agglutinin-agarose, a part of STAT5A was recovered in bound fractions. STAT5A of SDR or heterozygous rat nuclei were not bound to the lectin. Electrophoretic mobility shift assay revealed that STAT5A modified with O-GlcNAc is bound to the STAT5-responsive element. These results indicate that the mammary glands of HHR showed terminal differentiation for a short period, followed immediately by involution. In HHR, STAT5A is modified with O-GlcNAc but is not Tyr-phosphorylated. This type of glycosylation is suggested to be involved in the transient activation of STAT5A in HHR.

Resuspension of DNA sequencing reaction products in agarose increases sequence quality on an automated sequencer

We are investigating approaches to increase DNA sequencing quality. Since a majorfactor in sequence generation is the cost of reagents and sample preparations, we have developed and optimized methods to sequence directly plasmid DNA isolated from alkaline lysis preparations. These methods remove the costly PCR and post-sequencing purification steps but can result in low sequence quality when using standard resuspension protocols on some sequencing platforms. This work outlines a simple, robust, and inexpensive resuspension protocol for DNA sequencing to correct this shortcoming. Resuspending the sequenced products in agarose before electrophoresis results in a substantial and reproducible increase in sequence quality and read length over resuspension in deionized water and has allowed us to use the aforementioned sample preparation methods to cut considerably the overall sequencing costs without sacrificing sequence quality. We demonstrate that resuspension of unpurified sequence products generated from template DNA isolated by a modified alkaline lysis technique in low concentrations of agarose yields a 384% improvement in sequence quality compared to resuspension in deionized water. Utilizing this protocol, we have produced more than 74,000 high-quality, long-read-length sequences from plasmid DNA template on the MegaBACET 1000 platform.

A case of well-differentiated minute hepatocellular carcinoma with extrahepatic metastasis

A rare case of well-differentiated minute hepatocellular carcinoma (HCC) metastasizing to distant sites in a 77-year-old man with hepatitis C virus (HCV)-related cirrhosis is presented. Ultrasonography (US) disclosed a 9 mm hypoechoic lesion in segment seven (S7) of the liver, although computed tomography (CT), magnetic resonance imaging (MRI) and angiography did not reveal any space-occupying lesion. Ultrasound-guided biopsy showed the histological features of well-differentiated HCC. A plain film of the abdomen and CT revealed osteolytic changes in the sacrum and the lumbar vertebra. Ultrasound-guided biopsy of the sacrum revealed well-to-moderately differentiated HCC metastasizing from the liver. Percutaneous ethanol injection therapy (PEIT) effected complete response and completely eliminated the abnormal findings on US. Three months after PEIT, metastasis to the thoracic vertebra was revealed by CT, despite negative alpha-fetoprotein-mRNA in serum. This is the first report describing a well-differentiated HCC with metastatic potential. Further studies may provide insights into metastasis of well-differentiated HCC.

Functional analysis of vif genes derived from various primate immunodeficiency viruses

Replication property in cells of human and simian immunodeficiency viruses (HIVs and SIVs) lacking intact vif gene was evaluated. Of 10 vif mutants constructed in vitro of the major four HIV/SIV groups, only those derived from HIV-1 and HIV-2/SIVmac displayed replication defect. The cell lines non-permissive for the vif mutants of HIV-1 and SIVmac were found to be different. To determine whether Vif is exchangeable between HIV-1 and SIVmac, chimeric virus clones with respect to the vi gene were constructed and virus replication in the cells non-permissive for the vif mutant viruses was monitored. Productive infection in these cells of chimeric viruses clearly indicated that Vif is functionally exchangeable, and that Vifs of different virus origin act through a similar mechanism.

Effect of pulsed output ultrasound on the transdermal absorption of indomethacin from an ointment in rats

The effect of pulsed output ultrasound (1 MHz) with on/off ratios of 1:2, 1:4 and 1:9 on transdermal absorption of indomethacin from an ointment was studied in rats. Ultrasound energy was supplied for between 10 and 19 min at a range of intensities (1.0-2.5 W.cm-2), energy levels commonly used for therapeutic purposes. The on/off pulsed ratio, intensity and the time of application were found to play an important role in the transdermal phonophoretic delivery system of indomethacin; 1:2 pulsed output ultrasound appeared to be the most effective in improving the transdermal absorption. The highest penetration was observed at an intensity of 1.0 W.cm-2 and application time of 15 min. With pulsed output it was possible to use higher intensities of ultrasound without increasing skin temperature or damaging skin.

Antiviral activity of lignans and their glycosides from Justicia procumbens

Ten antiviral lignans, seven known (justicidins A, B, C and D, diphyllin, diphyllin apioside and diphyllin apioside-5-acetate) and three new compounds, justicidinosides A (justicidin C 6'-O-glucoside), B (justicidin A 6'-O-glucoside) and C (justicidin B 6'-O-glucoside), were isolated from a methanolic extract of the aerial parts of Justicia procumbens var. leucantha. Justicidins A and B, diphyllin, diphyllin apioside and diphyllin apioside-5-acetate showed strong antiviral activity (the MIC were less than 0.25 microgram ml-1, respectively) against vesicular stomatitis virus and low cytotoxicity (the MTC were larger than 31 micrograms ml-1, respectively) against cultured rabbit lung cells (RL-33).

Cytotoxic xanthones from Garcinia hanburyi

Eleven novel cytotoxic xanthones, gambogin, morellin dimethyl acetal, isomoreollin B, moreollic acid, gambogenic acid, gambogenin, isogambogenin, desoxygambogenin, gambogenin dimethyl acetal, gambogellic acid and hanburin were isolated together with four known xanthones, gambogic acid, isomorellin, morellic acid and desoxymorellin, from the dry latex of Garcinia hanburyi. The structures were elucidated by a detailed spectroscopic analysis.

Effects of erucic acid therapy on Japanese patients with X-linked adrenoleukodystrophy

Ten Japanese boys with childhood adrenoleukodystrophy (ALD), one adult patient with adrenomyeloneuropathy (AMN), and two presymptomatic ALD boys were treated with dietary erucic acid (C22:1) for more than 12 months; except in a case of childhood ALD patient who died 7 months after beginning erucic acid therapy. During erucic acid therapy, the serum levels of very long-chain fatty acid (VLCFA) (C24:0/C22:0) decreased within 1-2 months in all patients, and these levels in four of the patients decreased to the normal range. Neurological examination and MRI findings in all 10 of the childhood ALD patients showed progression of the disease while they were receiving the dietary therapy. However, the mean interval between the onset of awkward gait and a vegetative state in diet-treated patients was significantly longer than that in the untreated patients. One AMN patient showed slight improvement of spastic gait and lessened pain in the lower limbs due to spasticity. The two presymptomatic ALD boys remained intact on clinical examination and on MRI findings for 38 and 23 months, respectively, after starting the diet.

Thyroid cancer in a case with the Alagille syndrome

A 19-year-old woman with the Alagille syndrome developed papillary thyroid carcinoma with lung metastasis. She was diagnosed as having Alagille syndrome at the age of 8. Following total thyroidectomy and lymph nodes dissection, iodine-131 therapy was conducted for local and distant metastases. This is the first report of a case of thyroid cancer accompanying Alagille syndrome.

Balanced complex rearrangement involving chromosomes 8, 9, and 12 in a normal mother, derivative chromosome 9 with recombinant chromosome 12 in her daughter with minor anomalies

We report on a 19-month-old girl with a derivative chromosome 9 and a recombinant chromosome 12 resulting from a maternal balanced complex rearrangement involving chromosomes 8, 9, and 12. The karyotype of the phenotypically normal mother was 46,XX,t(8;12) (9;12) (8qter-->8p23::12q12-->12q 15::9q32-->9qter;9pter-->9q32::12q15--> 12qter; 12pter-->12q12::8p23-->8pter). The child's karyotype was 46,XX,-9,-12, +der(9) (9pter-->9q32::12q15-->12qter), +rec(12) (12pter-->12q15::9q32-->9qter) mat. The child had severe growth retardation, minor anomalies including trigonocephaly, hypertelorism, broad nasal root, apparently low-set and posteriorly angulated ears, triangular face, pectus carinatum, clinodactyly of fifth fingers, and almost normal psychomotor development. To the best of our knowledge, there have been only 3 previous reports of recombination derived from parental complex chromosome rearrangements. In the recombination products, the chromosomes were apparently balanced and the offspring had no clinical abnormalities. The present case exhibited abnormalities and may have a submicroscopic aberration of 12q arising from crossing over during maternal meiotic pairing, although her chromosomes appeared to be balanced.

Improvement of clinical and MRI findings in a boy with adrenoleukodystrophy by dietary erucic acid therapy

A 5-year-old boy with adrenoleukodystrophy, with clinical symptoms of visual, mental and motor disturbances which progressed rapidly, was treated with Lorenzo's oil consisting 1 volume of glyceryl trierucate and 4 volumes of glyceryl trioleate. Five months after initiation of this therapy, ability to swallow was enhanced and T2-weighted magnetic resonance imaging of the brain revealed regression of high intensity area of the parieto-occipital white matter.

Gene deletions in Japanese patients with Duchenne and Becker muscular dystrophies: deletion study and carrier detection

Fifty unrelated Japanese patients with Duchenne and Becker muscular dystrophy (DMD and BMD) have been studied through use of the dystrophin cDNA probes. The 14-kb dystrophin cDNA was subdivided into six subclones, and Hind III-digested DNAs were analyzed by Southern blotting. Of 50 unrelated patients, 20 showed a deletion of one or several of the exon-containing Hind III fragments (40.0%). These corresponded to 50% (11/22) of BMD patients and 32.1% (9/28) of DMD patients, and the position and extent of deletions were mapped and proven to be more heterogeneous in DMD than in BMD. Both ends of deletions detected by probe 1-2a were common to all six BMD patients, and the 5' ends of deletions in probe 5b-7 were also common to four BMD patients. The phenotypic-specific deletion in Japanese BMD patients existed in the 5' end of the DMD gene, although an apparently similar deletion produced a wide range of clinical courses (BMD phenotype). Three out of eight females in DMD/BMD families were diagnosed as carriers through use of the junctional fragment and dosage analyses of dystrophin cDNA.

[CT findings and prognoses of anoxic brain damage due to near-drowning in children]

We investigated the relationship between serial cranial CT findings and prognoses in 11 children after near-drowning. These patients were rescued after heart arrest for more than 10 minutes and all comatose on admission. CT scans were performed within 2 weeks, at 3 weeks-1 month, 2-4 months and more than 5 months after admission. Characteristics of CT findings and prognoses were classified into four groups. Group 1: low density areas in thalami, basal ganglia and cortical white matters within 2 weeks (three cases; one died, two became vegetative). Group 2: enlargement of the third ventricle at 3 weeks-1 month, and atrophy of pons at 2-4 months (three cases; severe quadriplegia and mental retardation). Group 3: enlargement of the third ventricle at 3 weeks-1 month, but atrophy of pons not observed at 2-4 months (three cases; mild motor disabilities and mild mental retardation). Group 4: enlargement of third ventricle not observed at 3 weeks-1 month (two cases; neither paralysis nor mental retardation).

Gene deletions in Japanese patients with Duchenne and Becker muscular dystrophy

Thirty-eight unrelated Japanese patients with Duchenne and Becker muscular dystrophy (DMD and BMD) have been investigated with the DMD cDNA probes. The 14-kb DMD cDNA was subdivided into 6 subclones and HindIII-digested DNAs were analyzed by Southern blotting. Out of 38 unrelated patients, 14 showed a deletion of one or several of the exon-containing HindIII fragments (36.8%). These corresponded to 50% (9/18) of BMD patients and 25% (5/20) of DMD patients, and the position and extent of deletions were mapped and proved to be more heterogeneous in DMD than in BMD. Both ends of deletions detected in probe 1-2a were common to all six BMD patients without the maintenance of reading frame of messenger RNA, and 5' ends of deletions in probe 5b-7 were also common but maintained in frame in three BMD patients. The phenotypic-specific deletion in Japanese BMD patients has existed in the 5' end of the DMD gene, although its apparently similar deletion produced a wide range of clinical courses (BMD phenotype). There was no tight correlation between clinical severity and presence or absence of deletion in DMD or BMD.

[Prevention of postoperative infection following cardiac catheterization in pediatric field. Study of air-borne bacteria in X-ray room and evaluation of an antibiotic used for prevention of postoperative infection]

As part of preventive measures against postoperative infection following cardiac catheterization in infants with cardiac diseases, especially falling bacteria in X-ray room was studied. Moreover, a synthetic penicillin, ticarcillin (TIPC), was used as preventive antibiotic against postoperative infections due to falling bacteria which probably contaminate the air in the X-ray examination room, and the efficacy and side effects of the drug were observed. As result, coagulase-negative Staphylococcus was detected the most, followed by Micrococcus and then by fungus. The number of these 3 organisms corresponded to 90.3% of the total number of falling bacteria detected during operation. The number of falling bacteria during operation was 5.1 times larger than that before operation. Taking into account normal flora of skin, falling bacteria present in the X-ray room and causative organisms of bacterial endocarditis, TIPC was administered to 30 cases intravenously 5 times at a dose of 30 mg/kg every 8 hours for the purpose of preventing possible postoperative infections following cardiac catheterization. The drug was effective to prevent such infections in all cases. No side effects were noted in any case, in peripheral blood and hepatic function tests and other observations.

Antibiotic resistance of indole-positive Klebsiella pneumoniae

Resistance patterns to antibiotics differed markedly between indole-positive and indole-negative Klebsiella pneumoniae strains. Multiple-drug-resistant strains were almost exclusively indole-negative. Ampicillin and kanamycin resistances in the indolepositive strains tested were not transmissible, whereas many of those resistances in the indole-negative strains were transmissible, together with other drug resistances to an Escherichia coli recipient. The substrate profile of the beta-lactamase from the indole-positive strains was fairly different from that of the beta-lactamase mediated by the ampicillin resistance plasmid.