Comparison of Lens Biochemistry and Structure between BSO-treated and Glucocorticoid-treated Developing Chick Embryos

In this paper various changes in glutathione level, which were influenced by balance of its synthesis, degradation, transport and utilization, were analysed in chick embryos administered with glucocorticoid (GC) or buthionine sulfoximine (BSO; an inhibitor of glutathione synthesis). When BSO (30 μmol egg⁻¹) was administered twice to chick embryos on day 14 and 15, the GSH in both the lens and the liver decreased to 15–20% and 30–40% of the age-matched control level, respectively, between 24 and 48 hr after the second treatment, then began to recover. Although this decline in the GSH level in these tissues was greater and more prolonged in embryos treated with BSO than with GC, the former embryos maintained lens transparency even up to 144 hr by a visual examination. However, histological changes in the lens occurred after 96 hr and more significantly 144 hr after second administration of BSO. The changes mainly consisted of pale epithelial cells on the anterior peripheral surface of the lens, irregular height of the epithelial cells at the equator, clefts between the epithelium and the cortex and swelling of almost all the cortical fibers. These observations may suggest that BSO treatment could produce the beginning of a cataract. Embryos with GC-cataract revealed the following changes at 48 hr: loss of transparency, elevation of LPO (TBA-reacting substance) in the lens, the blood and the liver. These were not observed in BSO-treated embryos during the experimental period. The GC-cataract may well depend on the generation of LPO. BSO cataract, having a distinct mechanism compared to that caused by GC, develops more slowly in GSH-depleted lenses. The BSO-treated chick embryos will be a useful model to screen the risk factors which accelerate cataract formation.     

Gastrointestinal perforation in very low-birthweight infants

BACKGROUND: Spontaneous isolated gastrointestinal perforation (SIP) in very low-birthweight infants has been reported as a different disease entity from necrotizing enterocolitis (NEC). The objective of this study was to investigate the incidence and risk factors of NEC and SIP. METHODS: The authors reviewed the medical records of very low-birthweight infants who were admitted to Toho University Perinatal Center, Tokyo, Japan, between 1 January 1991 and 31 December 2002. The diagnosis of NEC was made with the finding of bloody gastric fluid or stool, abdominal distention, and abnormal abdominal X-ray findings such as pneumatosis intestinalis or fixed dilated intestinal loops. SIP was defined at laparotomy as the presence of an isolated gastrointestinal perforation surrounded by normal appearing bowel. RESULTS: A total of 556 very low-birthweight infants were included in this study. Of those, 15 infants were excluded because of major anomalies. Out of 541 infants, 14 were diagnosed to have NEC or gastrointestinal perforation. In total, 13 infants had gastrointestinal perforation and 10 were confirmed as SIP. Two SIP suggestive cases were included in SIP cases. There was only one case of NEC (0.2%) during 12 years in the authors' institute. Eight SIP cases had antenatal nonsteroidal anti-inflammatory drugs (NSAID). The treatment with antenatal NSAID was significantly associated with the incidence of SIP (p<0.001). CONCLUSION: The authors experienced only one proven case of NEC (0.2%), 12 cases of SIP (2.2%) among 556 very low-birthweight infants admitted during 12 years. Antenatal NSAID were strongly associated with SIP.     

Outbreak of CTX‐M‐15‐producing Klebsiella pneumoniae of sequence type 199 in a Latvian teaching hospital

Dumpis U, Iversen A, Balode A, Saule M, Mikla?evi?s E, Giske CG. Outbreak of CTX‐M‐15‐producing Klebsiella pneumoniae of sequence type 199 in a Latvian teaching hospital. APMIS 2010; 118: 713–6. Previous studies on the epidemiology of extended‐spectrum β‐lactamase (ESBL)‐producing Enterobacteriaceae in Latvia are lacking. ESBL‐producing Klebsiella pneumoniae (n = 32) were subjected to pulsed‐field gel electrophoresis (PFGE) and selected isolates to multi‐locus sequence typing (MLST). Species identification and susceptibility testing were performed using VITEK2, and sequencing of bla_CTX‐M was performed in selected isolates. PFGE revealed one major clone (n = 23), with most of the isolates derived from the ICU. The clone harboured bla_CTX‐M‐15, was sequence type 199 and comprised two ertapenem non‐susceptible isolates. This is the first report of an ESBL outbreak in Latvia, and calls for increased epidemiological typing of ESBL‐producing Enterobacteriaceae, as well as improved infection control routines.     

Ultrastructural characteristics and lectin-binding properties of M cells in the follicle-associated epithelium of chicken caecal tonsils

To clarify the nature of M cells, the detailed ultrastructural characteristics and lectin-binding properties of M cells were investigated in follicle-associated epithelium (FAE) of chicken caecal tonsils. M cells presented various outlines from columnar to dome shaped. Their polymorphism was dependent on the number of harboured intraepithelial migrating cells. The lighter and larger nuclei of M cells were situated at more apical levels in the epithelial lining compared with those of neighbouring microvillous epithelial cells. The microvilli, which were significantly shorter and thicker than those of adjacent microvillous epithelial cells, were sparsely distributed or completely absent on the apical surfaces of M cells. In general, the apical cytoplasm of M cells without microvilli protruded slightly into the intestinal lumen. Numerous small vesicles were often contained in the apical cytoplasm. The numerous small invaginations of the apical and lateral cell surfaces suggested active transportation of luminal substances. No canaliculi existed in the apical cytoplasm of M cells whereas they were often detected in the neighbouring microvillous epithelial cells. A noteworthy finding was the frequent detection of multivesicular bodies in the apical cytoplasm of M cells. These multivesicular bodies suggest some degradation of ingested luminal substances during transcytoplasmic transportation. WGA and 4 other lectins strongly reacted with all epithelial cells except for M cells, this negativity suggesting a means of detecting M cells in chicken caecal tonsils. Three lectins, DSL, ConA and Jacalin, reacted weakly with the glycocalyx on M cells. The positive reactivity might allow chicken M cells to be utilised for specific antigen delivery into the mucosal immune system in some parenteral vaccinations.