Trappc9 deficiency in mice impairs learning and memory by causing imbalance of dopamine D1 and D2 neurons

Genetic mutations in the gene encoding transport protein particle complex 9 (trappc9), a subunit of TRAPP that acts as a guanine nucleotide exchange factor for rab proteins, cause intellectual disability with brain structural malformations by elusive mechanisms. Here, we report that trappc9-deficient mice exhibit a broad range of behavioral deficits and postnatal delay in growth of the brain. Contrary to volume decline of various brain structures, the striatum of trappc9 null mice was enlarged. An imbalance existed between dopamine D1 and D2 receptor containing neurons in the brain of trappc9-deficient mice; pharmacological manipulation of dopamine receptors improved performances of trappc9 null mice to levels of wild-type mice on cognitive tasks. Loss of trappc9 compromised the activation of rab11 in the brain and resulted in retardation of endocytic receptor recycling in neurons. Our study elicits a pathogenic mechanism and a potential treatment for trappc9-linked disorders including intellectual disability.

Kalirin Interacts with TRAPP and Regulates Rab11 and Endosomal Recycling

Coordinated actions of Rab and Rho are necessary for numerous essential cellular processes ranging from vesicle budding to whole cell movement. How Rab and Rho are choreographed is poorly understood. Here, we report a protein complex comprised of kalirin, a Rho guanine nucleotide exchange factor (GEF) activating Rac1, and RabGEF transport protein particle (TRAPP). Kalirin was identified in a mass spectrometry analysis of proteins precipitated by trappc4 and detected on membranous organelles containing trappc4. Acute knockdown of kalirin did not affect trappc4, but significantly reduced overall and membrane-bound levels of trappc9, which specifies TRAPP toward activating Rab11. Trappc9 deficiency led to elevated expression of kalirin in neurons. Co-localization of kalirin and Rab11 occurred at a low frequency in NRK cells under steady state and was enhanced upon expressing an inactive Rab11 mutant to prohibit the dissociation of Rab11 from the kalirin-TRAPP complex. The small RNA-mediated depletion of kalirin diminished activities in cellular membranes for activating Rab11 and resulted in a shift in size of Rab11 positive structures from small to larger ones and tubulation of recycling endosomes. Our study suggests that kalirin and TRAPP form a dual GEF complex to choreograph actions of Rab11 and Rac1 at recycling endosomes.

The Function and Regulatory Network of Pax9 Gene in Palate Development

Cleft palate, a common congenital deformity, can arise from disruptions in any stage of palatogenesis, including palatal shelf growth, elevation, adhesion, and fusion. Paired box gene 9 (Pax9) is recognized as a vital regulator of palatogenesis with great relevance to cleft palate in humans and mice. Pax9-deficient murine palatal shelves displayed deficient elongation, postponed elevation, failed contact, and fusion. Pax9 is expressed in epithelium and mesenchyme, exhibiting a dynamic expression pattern that changes according to the proceeding of palatogenesis. Recent studies highlighted the Pax9-related genetic interactions and their critical roles during palatogenesis. During palate growth, PAX9 interacts with numerous molecules and members of pathways (e.g., OSR2, FGF10, SHOS2, MSX1, BARX1, TGFβ3, LDB1, BMP, WNT β-catenin dependent, and EDA) in the mesenchyme and functions as a key mediator in epithelial-mesenchymal communications with FGF8, TBX1, and the SHH pathway. During palate elevation, PAX9 is hypothesized to mediate the time point of the elevation event in the anterior and posterior parts of the palatal shelves. The delayed elevation of Pax9 mutant palatal shelves probably results from abnormal expressions of a series of genes ( Osr2 and Bmpr1a) leading to deficient palate growth, abnormal tongue morphology, and altered hyaluronic acid distribution. The interactions between PAX9 and genes encoding the OSR2, TGFβ3, and WNT β-catenin-dependent pathways provide evidence that PAX9 might participate in the regulation of palate fusion. This review summarizes the current understanding of PAX9’s functions and emphasizes the interactions between PAX9 and vital genes during palatogenesis. We hope to provide some clues for further exploration of the function and mechanism of PAX9, especially during palate elevation and fusion events.

The symbiotic bacterial surface factor polysaccharide A on Bacteroides fragilis inhibits IL-1β-induced inflammation in human fetal enterocytes via toll receptors 2 and 4

Colonizing bacteria interacting with the immature, unlike the mature, human intestine favors inflammation over immune homeostasis. As a result, ten percent of premature infants under 1500 grams weight develop an inflammatory necrosis of the intestine after birth, e.g., necrotizing enterocolitis (NEC). NEC is a major health problem in this population causing extensive morbidity and mortality and an enormous expenditure of health care dollars. NEC can be prevented by giving preterm infants their mother’s expressed breast milk or ingesting selective probiotic organisms. Vaginally delivered, breast fed newborns develop health promoting bacteria (“pioneer” bacteria) which preferentially stimulate intestinal host defense and anti-inflammation. One such “pioneer” organism is Bacteroides fragilis with a polysaccharide (PSA) on its capsule. B. fragilis has been shown developmentally in intestinal lymphocytes and dendritic cells to produce a balanced T-helper cell (TH1/TH2) response and to reduce intestinal inflammation by activity through the TLR2 receptor stimulating IL-10 which inhibits IL-17 causing inflammation. No studies have been done on the role of B. fragilis PSA on fetal enterocytes and its increased inflammation. Accordingly, using human and mouse fetal intestinal models, we have shown that B. fragilis with PSA and PSA alone inhibits IL-1β-induced IL-8 inflammation in fetal and NEC intestine. We have also begun to define the mechanism for this unique inflammation noted in fetal intestine. We have shown that B. fragilis PSA anti-inflammation requires both the TLR2 and TLR4 receptor and is in part mediated by the AP1 transcription factor (TLR2) which is developmentally regulated. These observations may help to devise future preventative treatments of premature infants against NEC.

Autologous dermal graft combined with a modified degloving procedure for penile augmentation in young adults: a preliminary study

In order to evaluate the effect of penile enhancement, we retrospectively reviewed the data of the patients operated with autologous dermal graft implantation combined with a modified penile degloving procedure. The patients with the complaints of small penis, asking for penile augmentation, and normal erectile function were psychologically screened and enrolled. Data of follow-up visit including patient demographics, medical history, surgical procedure, patient-reported outcomes were analysed. In all, 30 eligible persons were operated. After degloving of the penis, the suspensory ligament was incised and the tunica albuginea was fixed to the proximal tunica dartos at the penile base. Then, the dermis graft was implanted on the dorsal surface of the tunica albuginea. The file of follow-up visit was available in 17 (57%) patients. The mean age was 23.7 years (19-35 years) and the mean follow-up was 13 months (range, 4-24 months). During the follow-up period, the average gain in the penis length was 2.7 cm in flaccid and 0.8 cm in erection, respectively. And the average gain in the penis circumference was 1.5 cm in flaccid and 1.2 cm in erection, respectively. Also, psychosexual sexual self-esteem and confidence of the patients were significantly improved (p < 0.001). Overall, 13 (76%) patients reported satisfaction with the penile appearance. We believe that the surgery is both safe and effective in the enhancement of the penis, however, further clinical studies with a larger patient population are necessary.

Development of fatal intestinal inflammation in MyD88 deficient mice co-infected with helminth and bacterial enteropathogens

Infections with intestinal helminth and bacterial pathogens, such as enteropathogenic Escherichia coli, continue to be a major global health threat for children. To determine whether and how an intestinal helminth parasite, Heligomosomoides polygyrus, might impact the TLR signaling pathway during the response to a bacterial enteropathogen, MyD88 knockout and wild-type C57BL/6 mice were infected with H. polygyrus, the bacterial enteropathogen Citrobacter rodentium, or both. We found that MyD88 knockout mice co-infected with H. polygyrus and C. rodentium developed more severe intestinal inflammation and elevated mortality compared to the wild-type mice. The enhanced susceptibility to C. rodentium, intestinal injury and mortality of the co-infected MyD88 knockout mice were found to be associated with markedly reduced intestinal phagocyte recruitment, decreased expression of the chemoattractant KC, and a significant increase in bacterial translocation. Moreover, the increase in bacterial infection and disease severity were found to be correlated with a significant downregulation of antimicrobial peptide expression in the intestinal tissue in co-infected MyD88 knockout mice. Our results suggest that the MyD88 signaling pathway plays a critical role for host defense and survival during helminth and enteric bacterial co-infection.

Infections with intestinal helminths and enteric bacterial pathogens such as enteropathogenic Escherichia coli (EPEC) continue to be major global health problems, especially for children. The ability of the host to control bacterial enteropathogens may be influenced by host immune status and by concurrent infections. Helminth parasites are of particular interest in this context because of their ability to modulate host immune responses, and because their geographic distribution coincides with those parts of the world where infections caused by bacterial enteropathogens are most problematic. In this study, we determined how intestinal helminth infection regulates host innate immunity against bacterial enteropathogens by using a murine co-infection model. This model involves co-infection with the intestinal nematode parasite Heligmosomoides polygyrus and the Gram-negative bacterial pathogen Citrobacter rodentium, the murine equivalent of EPEC. The infections were carried out in wild-type mice and in mice lacking MyD88, a protein required for signaling by the Toll-like receptors. We found that co-infection with the helminth parasite significantly worsened Citrobacter-induced colitis in the MyD88-deficient mice, in association with increased mortality and compromised innate immune responses. Our observations demonstrate an important role for MyD88-dependent and -independent signaling in host survival during helminth and enteric bacterial co-infection.

Conditioned medium from Bifidobacteria infantis protects against Cronobacter sakazakii-induced intestinal inflammation in newborn mice

Necrotizing enterocolitis (NEC) is associated with a high morbidity and mortality in very low birth weight infants. Several hypotheses regarding the pathogenesis of NEC have been proposed but to date no effective treatment is available. Previous studies suggest that probiotic supplementation is protective. We recently reported that probiotic (Bifidobacterium infantis) conditioned medium (PCM) has an anti-inflammatory effect in cultured fetal human intestinal cells (H4) and fetal intestine explants. In this study, we tested in vivo whether PCM protects neonatal mice from developing intestinal inflammation induced by exposure to Cronobacter sakazakii (C. sakazakii), an opportunistic pathogen associated with NEC. We found that infected neonatal mice had a significantly lower body weight than control groups. Infection led to ileal tissue damage including villous rupture, disruption of epithelial cell alignment, intestinal inflammation, apoptotic cell loss, and decreased mucus production. Pretreatment with PCM prevented infection caused decrease in body weight, attenuated enterocyte apoptotic cell death, mitigated reduced mucin production, and maintained ileal structure. Infected ileum expressed reduced levels of IκBα, which could be restored upon pretreatment with PCM. We also observed a nuclear translocation of NF-κB p65 in H4 cells exposed to C. sakazakii, which was prevented in PCM-pretreated cells. Finally, treatment of neonatal mice with PCM prior to infection sustained the capacity of ileal epithelial proliferation. This study suggests that an active component(s) released into the culture medium by B. infantis may prevent ileal damage by a pathogen linked to NEC.

Eosinophils are necessary for pulmonary arterial remodeling in a mouse model of eosinophilic inflammation-induced pulmonary hypertension

There is increasing evidence that inflammation plays a pivotal role in the pathogenesis of some forms of pulmonary hypertension (PH). We recently demonstrated that deficiency of adiponectin (APN) in a mouse model of PH induced by eosinophilic inflammation increases pulmonary arterial remodeling, pulmonary pressures, and the accumulation of eosinophils in the lung. Based on these data, we hypothesized that APN deficiency exacerbates PH indirectly by increasing eosinophil recruitment. Herein, we examined the role of eosinophils in the development of inflammation-induced PH. Elimination of eosinophils in APN-deficient mice by treatment with anti-interleukin-5 antibody attenuated pulmonary arterial muscularization and PH. In addition, we observed that transgenic mice that are devoid of eosinophils also do not develop pulmonary arterial muscularization in eosinophilic inflammation-induced PH. To investigate the mechanism by which APN deficiency increased eosinophil accumulation in response to an allergic inflammatory stimulus, we measured expression levels of the eosinophil-specific chemokines in alveolar macrophages isolated from the lungs of mice with eosinophilic inflammation-induced PH. In these experiments, the levels of CCL11 and CCL24 were higher in macrophages isolated from APN-deficient mice than in macrophages from wild-type mice. Finally, we demonstrate that the extracts of eosinophil granules promoted the proliferation of pulmonary arterial smooth muscle cells in vitro. These data suggest that APN deficiency may exacerbate PH, in part, by increasing eosinophil recruitment into the lung and that eosinophils could play an important role in the pathogenesis of inflammation-induced PH. These results may have implications for the pathogenesis and treatment of PH caused by vascular inflammation.

Adiponectin decreases pulmonary arterial remodeling in murine models of pulmonary hypertension

Remodeling of the pulmonary arteries is a common feature among the heterogeneous disorders that cause pulmonary hypertension. In these disorders, the remodeled pulmonary arteries often demonstrate inflammation and an accumulation of pulmonary artery smooth muscle cells (PASMCs) within the vessels. Adipose tissue secretes multiple bioactive mediators (adipokines) that can influence both inflammation and remodeling, suggesting that adipokines may contribute to the development of pulmonary hypertension. We recently reported on a model of pulmonary hypertension induced by vascular inflammation, in which a deficiency of the adipokine adiponectin (APN) was associated with the extensive proliferation of PASMCs and increased pulmonary artery pressures. Based on these data, we hypothesize that APN can suppress pulmonary hypertension by directly inhibiting the proliferation of PASMCs. Here, we tested the effects of APN overexpression on pulmonary arterial remodeling by using APN-overexpressing mice in a model of pulmonary hypertension induced by inflammation. Consistent with our hypothesis, mice that overexpressed APN manfiested reduced pulmonary hypertension and remodeling compared with wild-type mice, despite developing similar levels of pulmonary vascular inflammation in the model. The overexpression of APN was also protective in a hypoxic model of pulmonary hypertension. Furthermore, APN suppressed the proliferation of PASMCs, and reduced the activity of the serum response factor-serum response element pathway, which is a critical signaling pathway for smooth muscle cell proliferation. Overall, these data suggest that APN can regulate pulmonary hypertension and pulmonary arterial remodeling through its direct effects on PASMCs. Hence, the activation of APN-like activity in the pulmonary vasculature may be beneficial in pulmonary hypertension.

Mechanism of regulating the expression of lambdaN gene by ribosomal protein at translational level

In ribosomal protein S12 mutant or L24 mutant the expression of lambdaN gene was depressed at translational level. To study its mechanism the lambdaN gene region of lambdaN -lacZ gene fusion was trimmed from its 5' end to 3' end with DNA exonuclease III (DNA exoIII) in order to alter the TIR (translational initiation region) and the coding region of lambdaN gene. After DNA sequencing 23 species of different lambdaN-lacZ fused genes were obtained. The beta-galactosidase activities of these deletants in ribosomal protein mutant were compared with that in wild type strain. The result indicated that (i) S12 mutant could affect 305 subunit's binding to the TIR of lambdaN gene messenger and cause the difficulty in forming 30s initiation complex and then decrease the efficiency of translational initiation; (ii) in S12 mutant the coding region of lambdaN gene also affected the expression lambdaN gene; (iii) in L24 mutant the inhibition of lambdaN gene expression was not related to translational initiation and the 5' end of the coding region of lambdaN gene, but related to the 3' end of lambdaN gene.

Fatty acid binding protein 4 is a target of VEGF and a regulator of cell proliferation in endothelial cells

Fatty acid binding protein 4 (FABP4) plays an important role in maintaining glucose and lipid homeostasis. FABP4 has been primarily regarded as an adipocyte- and macrophage-specific protein, but recent studies suggest that it may be more widely expressed. We found strong FABP4 expression in the endothelial cells (ECs) of capillaries and small veins in several mouse and human tissues, including the heart and kidney. FABP4 was also detected in the ECs of mature human placental vessels and infantile hemangiomas, the most common tumor of infancy and ECs. In most of these cases, FABP4 was detected in both the nucleus and cytoplasm. FABP4 mRNA and protein levels were significantly induced in cultured ECs by VEGF-A and bFGF treatment. The effect of VEGF-A on FABP4 expression was inhibited by chemical inhibition or short-hairpin (sh) RNA-mediated knockdown of VEGF-receptor-2 (R2), whereas the VEGFR1 agonists, placental growth factors 1 and 2, had no effect on FABP4 expression. Knockdown of FABP4 in ECs significantly reduced proliferation both under baseline conditions and in response to VEGF and bFGF. Thus, FABP4 emerged as a novel target of the VEGF/VEGFR2 pathway and a positive regulator of cell proliferation in ECs.

Adiponectin deficiency increases allergic airway inflammation and pulmonary vascular remodeling

Obesity is associated with an increased incidence and severity of asthma, as well as other lung disorders, such as pulmonary hypertension. Adiponectin (APN), an antiinflammatory adipocytokine, circulates at lower levels in the obese, which is thought to contribute to obesity-related inflammatory diseases. We sought to determine the effects of APN deficiency in a murine model of chronic asthma. Allergic airway inflammation was induced in APN-deficient mice (APN(-/-)) using sensitization without adjuvant followed by airway challenge with ovalbumin. The mice were then analyzed for changes in inflammation and lung remodeling. APN(-/-) mice in this model develop increased allergic airway inflammation compared with wild-type mice, with greater accumulation of eosinophils and monocytes in the airways associated with elevated lung chemokine levels. Surprisingly, APN(-/-) mice developed severe pulmonary arterial muscularization and pulmonary arterial hypertension in this model, whereas wild-type mice had only mild vascular remodeling and comparatively less pulmonary arterial hypertension. Our findings demonstrate that APN modulates allergic inflammation and pulmonary vascular remodeling in a model of chronic asthma. These data provide a possible mechanism for the association between obesity and asthma, and suggest a potential novel link between obesity, inflammatory lung disease, and pulmonary hypertension.

Alternatively activated macrophages in intestinal helminth infection: effects on concurrent bacterial colitis

The distribution of several pathogenic helminth infections coincides geographically with many devastating microbial diseases, including enteric bacterial infections. To dissect the mechanisms by which helminths modulate the host's response to enteric bacteria and bacteria-mediated intestinal inflammation, we have recently established a coinfection model and shown that coinfection with the helminth Heligmosomoides polygyrus exacerbates colitis induced by infection with the gram-negative bacterial pathogen Citrobacter rodentium. The disease severity of the coinfected mice was correlated with high Citrobacter loads in the gut, translocation of the bacteria into mucosal and systemic immune compartments, delayed bacterial clearance, and a significantly enhanced colonic TNF-alpha response. In the present study, using our in vivo coinfection model as well as in vitro approaches, we test the hypothesis that the phenotypic and functional alterations in macrophages induced by the helminth-driven T cell response may contribute to the observed alterations in the response to C. rodentium. We show that via a STAT6-dependent mechanism H. polygyrus coinfection results in a marked infiltration into the colonic lamina propria of F4/80+ cells that have the phenotype of alternatively activated macrophages. Functional analysis of these macrophages further shows that they are impaired in their killing of internalized bacteria. Yet, these cells produce an enhanced amount of TNF-alpha in response to C. rodentium infection. These results demonstrate that helminth infection can impair host protection against concurrent enteric bacterial infection and promote bacteria-induced intestinal injury through a mechanism that involves the induction of alternatively activated macrophages.

Butyrate regulates the expression of pathogen-triggered IL-8 in intestinal epithelia

Inflammatory bowel disease (IBD) is characterized by an exaggerated immune response that involves pro-inflammatory cytokines including IL-8. Production of these pro-inflammatory cytokines is triggered by pathogen-associated molecular patterns (PAMP). Butyrate, a product of bacterial fermentation of carbohydrates, has been reported to modulate inflammation in IBD, possibly by regulating production of pro-inflammatory cytokines. However, this effect of butyrate is controversial. In this study, we used Pam3CSK4 (Pam3CysSerLys4), the acylated NH2-terminus of the bacterial lipoprotein (a PAMP), to mimic in vivo infection of pathogens. Butyrate transiently down-regulated expression of IL-8 stimulated by Pam3CSK4. Treatment of cells with butyrate before Pam3CSK4, however, enhanced production of IL-8. Furthermore, butyrate induced expression of A20, a negative regulator of the nuclear factor-kappaB pathway. Over-expression of A20 inhibited Pam3CSK4-triggered IL-8 expression. Our data suggest that the inflammatory modulation of butyrate in IBD is mediated by A20 and a short pulse rather than continuous administration of butyrate may provide a protective effect on IBD.

Cathepsin S deficiency confers protection from neonatal hyperoxia-induced lung injury

RATIONALE

Bronchopulmonary dysplasia (BPD) is a chronic lung disease that adversely affects long-term pulmonary function as well as neurodevelopmental outcomes of preterm infants. Elastolytic proteases have been implicated in the pathogenesis of BPD. Cathepsin S (cat S) is a cysteine protease with potent elastolytic activity. Increased levels and activity of cat S have been detected in a baboon model of BPD.

OBJECTIVES

To investigate whether deficiency of cat S alters the course of hyperoxia-induced neonatal lung injury in mice.

METHODS

Newborn wild-type and cat S-deficient mice were exposed to 80% oxygen for 14 days. Histologic and morphometric analysis were performed and bronchoalveolar lavage protein and cells were analyzed. Lung elastin was assessed by real-time polymerase chain reaction, in situ hybridization, desmosine analysis, and Hart's stain. Distribution of myofibroblasts was analyzed by immunofluorescence. Hydroxyproline content of lung tissues was measured.

MEASUREMENTS AND MAIN RESULTS

Hyperoxia-exposed cat S-deficient mice were protected from growth restriction and had improved alveolarization, decreased septal wall thickness, lower number of macrophages, and lower protein concentration in bronchoalveolar lavage fluid. alpha-Smooth muscle actin-expressing myofibroblasts accounted for at least some of the increased interstitial cellularity in hyperoxia-exposed mouse lungs and were significantly less in cat S-deficient lungs. Lung hydroxyproline content was increased in hyperoxia-exposed wild-type, but not in cat S-deficient lungs. Desmosine content was significantly reduced in both genotypes with hyperoxia.

CONCLUSIONS

Cathepsin S deficiency improves alveolarization, and attenuates macrophage influx and fibroproliferative changes in hyperoxia-induced neonatal mouse lung injury.

Mutations in the Bacillus subtilis purine repressor that perturb PRPP effector function in vitro and in vivo

The Bacillus subtilis pur operon repressor (PurR) has a PRPP (5-phosphoribosyl 1-pyrophosphate) binding motif at residues 199-211. Two PurR PRPP binding region mutations (D203A and D204A) were constructed, and the effects on binding of repressor to the pur operon control site in vitro and on regulation of pur operon expression in vivo were investigated. PRPP significantly inhibited the binding of wild-type but not mutant PurR to pur operon control site DNA. In strains with the D203A and D204A mutations, pur operon expression in vivo was super-repressed by addition of adenine to the growth medium. These results support the role of PRPP in modulating the regulatory function of PurR in vivo. YabJ, the product of the distal gene in the bicistronic purR operon, is also required for PurR function in vivo.

[Mutation induced by space conditions in Escherichia coli strains]

To study the mutagenesis of microorganism under space conditions, three Escherichia coli strains CSH108, A2 and A3, were flown on board the Chinese recoverable satellite (JB1 - B9611020) in Oct . 1996. Three ways of sample boarding were designed . After recovery, survival and frequency of lacI- mutation and Arg+ reversion were determined in the flight strains. The results showed that: E. coli strains could survive after the flight conditions. The lacI- mutation frequency of A3 strain in the biocabin was sixty - seven times that of the ground control, the Arg+ reversion frequency of CSH108 in the lead chamber, was ten times that of the ground control; and among the revertants the mutation frequency of non-sense suppressor increased remarkably. The results indicate that the space conditions may greatly enhance the mutation frequency of certain genes in the microorganism and may provide an effective method for microorganism breeding.

A novel photosensitizer, 2-butylamino-2-demethoxy-hypocrellin A (2-BA-2-DMHA). 1. Synthesis of 2-BA-2-DMHA and its phototoxicity to MGC803 cells

The reaction of hypocrellin A (HA) with n-butylamine in pyridine under reflux leads to the formation of 2-butylamino-2-demethoxy-hypocrellin A (2-BA-2-DMHA), which is illustrated by ultraviolet-visible absorption spectra, proton nuclear magnetic resonance spectra, infrared spectra and mass spectra. The product exhibits stronger red-light absorption and has a much higher photopotentiation factor than HA (i.e., more than 200 versus four at a dose of 4 J cm-2 of red light on human gastric adenocarcinoma MGC803 cells). The mechanism of phototoxicity of 2-BA-2-DMHA on MGC803 cells irradiated with red light (lamada = 600-700 nm) has also been studied. An examination of extracted cellular DNA by agarose gel electrophoresis shows that the DNA has degraded into fragments with lengths which are multiples of approximately 180-190 base pairs (i.e., oligonucleosome size), a biochemical marker of apoptosis. Transmission electron microscopy reveals chromatin condensation around the periphery of the nucleus, which is also characteristic of apoptosis. This study suggests that 2-BA-2-DMHA is a potential photosensitizer and that its photoxicity to MGC803 cells proceeds via apoptosis.

The deltoid muscle origin. Histologic characteristics and effects of subacromial decompression

The histologic characteristics of the deltoid muscle attachment to nine cadaveric acromia were studied using light microscopy. The deltoid muscle attaches to the anterior and lateral acromion primarily by direct tendinous attachment. The muscle attaches to the dorsal side of the acromion by periosteal fiber attachment. In the specimens studied, a hypothetical acromioplasty of 4 mm would release, on average, 41% of the direct fiber attachment, and a 6-mm acromioplasty would release 69% for all zones examined histologically. The functional and clinical effects of these findings are not known, but the deltoid muscle would be released by arthroscopic acromioplasty in areas where bone is removed.

[Minor saponins from leaves of Panax ginseng C.A. Meyer]

Five compounds were isolated from the leaves of Panax ginseng and characterized as 20(R)-protopanaxatriol, daucosterine, ginsenoside-F2, ginsenoside-F3 and majoroside-F4 on the basis of spectral analysis and chemical evidence. Among them, majoroside-F4 is obtained from plant for the first time.

[Obesity-hypoventilation syndrome]

5 cases with obesity-hypoventilaion syndrome were reported. The clinical manifestations were obesity, palpitation, dyspnea, lethargy, cyanosis, distention of cervical vein, edema, enlargement of liver and hypertension. All of them were initially diagnosed as chronic bronchitis or heart diseases. Pulmonary function test showed restrictive ventilative defect and hypercapnia with hypoxemia. Mouth oclusion pressure at 0.1 second was higher than the normal value. The response to CO2 was decreased. Hypertrophy of right heart was shown in ECG and X-ray film improvement in symptoms and blood gases analyses were found to be associated with body weight decrease in a follow up period of one year.

Identification of the Bacillus subtilis pur operon repressor

Transcription of the Bacillus subtilis pur operon is repressed in response to a signal of excess adenine. We have purified the repressor protein and have identified, cloned, and overexpressed the purR regulatory gene that controls transcription initiation of the operon. B. subtilis purR encodes a 62-kDa homodimer that binds to the pur operon control region. The PurR binding site which overlaps the promoter encompasses approximately 110 bp. The protein-DNA interaction is inhibited by 5-phosphoribosyl 1-pyrophosphate. A mutation that deletes the repressor binding site or one that disrupts purR abolishes binding activity in vitro and repression of transcription in vivo in response to the excess adenine signal. These results lead to a model in which an excess-adenine signal is transmitted to PurR via the 5-phosphoribosyl 1-pyrophosphate pool. In addition, purR is autoregulated. There is no structural or mechanistic similarity between the B. subtilis and Escherichia coli purine repressors.

Effect of genetic dilution on development of diabetes, impaired glucose tolerance and in vitro glucose oxidation in LA/N-cp × SHR/N-cp F1 hybrid rats

1. To determine the effects of gene dilution on development of IGT, NIDDM and in vitro glucose oxidation, heterozygous lean LA/N-cp female and SHR/N-cp male rats were mated, and F1 offspring studied at periodic intervals to determine the prevalence of obese and diabetic traits. 2. Obesity occurred in 25% of offspring by 5 weeks of age, consistent with inheritance of the autosomal recessive cp trait. 3. IGT occurred in all obese male F1, 67% of obese female F1, and 18% of the lean male F1 rats by 5 months of age, and diabetes occurred in 80% of male obese and 17% of female obese rats from 6 months of age. Glycosuria occurred with glucose intolerance, and was more severe in rats with NIDDM than IGT. 4. Rates of in vitro glucose oxidation were greater in diaphragm and adipose tissue, and were greater in the presence of insulin (100 mu Units/ml) in obese female but not obese male F1 rats. 5. These results indicate that the development of glucose intolerance is more prominent in male than in female F1 rats, that the progression of IGT to NIDDM occurs later in life in the F1 hybrid than in the SHR/N-cp strain from which the diabetic trait was transmitted, and that genetic dilution of the diabetic trait via hybrid breeding results in a delay in the expression of NIDDM which is chronologically more similar to that which occurs in man.

Purification, characterization and comparison of two non-haem bromoperoxidases from Streptomyces aureofaciens ATCC 10762

Two non-haem bromoperoxidases (BPO 1 and BPO 2) were purified from the 7-chlorotetracycline-producing strain Streptomyces aureofaciens ATCC 10762. Both enzymes showed azide-insensitive brominating activity, and bromide-dependent peroxidase activity. BPO 1 was a dimer (Mr 65,000) with subunits of identical size (Mr 31,000). The pI was estimated to be 4.5. The enzyme did not cross-react with antibodies raised against the non-haem bromoperoxidase (Mr 90,000) from S. aureofaciens Tü24, a strain that also produces 7-chlorotetracycline. The Mr of BPO 2 was estimated to be 90,000. The enzyme had three identical subunits (Mr 31,000), and its isoelectric point was 3.5, identical with that of the bromoperoxidase from S. aureofaciens Tü24. Moreover, BPO 2 was immunologically identical with the bromoperoxidase from S. aureofaciens Tü24, although both it and BPO 1 could be distinguished electrophoretically from the latter bromoperoxidase.

Nucleotide sequence of Escherichia coli pyrG encoding CTP synthetase

The amino acid sequence of Escherichia coli CTP synthetase was derived from the nucleotide sequence of pyrG. The derived amino acid sequence, confirmed at the N terminus by protein sequencing, predicts a subunit of 544 amino acids having a calculated Mr of 60,300 after removal of the initiator methionine. A glutamine amide transfer domain was identified which extends from approximately amino acid residue 300 to the C terminus of the molecule. The CTP synthetase glutamine amide transfer domain contains three conserved regions similar to those in GMP synthetase, anthranilate synthase, p-aminobenzoate synthase, and carbamoyl-P synthetase. The CTP synthetase structure supports a model for gene fusion of a trpG-related glutamine amide transfer domain to a primitive NH3-dependent CTP synthetase. The major 5' end of pyrG mRNA was localized to a position approximately 48 base pairs upstream of the translation initiation codon. Translation of the gene eno, encoding enolase, is initiated 89 base pairs downstream of pyrG. The pyrG-eno junction is characterized by multiple mRNA species which are ascribed to monocistronic pyrG and/or eno mRNAs and a pyrG eno polycistronic mRNA.