Regional and annual patterns in respiratory virus co-infection etiologies and antibiotic prescriptions for pediatric mycoplasma pneumoniae pneumonia.

OBJECTIVE: Mycoplasma pneumoniae (M. pneumoniae) pneumonia is the second-most common cause of community-acquired pneumonia (CAP). This study aimed at investigating into the prevalence of macrolide-resistant M. pneumoniae (MRMP) with respiratory virus co-infection and the antibiotic prescriptions in children with CAP in four provinces in Korea, and to assess the variations in the findings across regions and throughout the year. PATIENTS AND METHODS: This prospective study was conducted in 29 hospitals in Korea between July 2018 and June 2020. Among the enrolled 1,063 children with CAP, all 451 patients with M. pneumoniae underwent PCR assays of M. pneumoniae and respiratory viruses, and the presence of point mutations of residues 2063 and 2064 was evaluated. RESULTS: Gwangju-Honam (88.6%) showed the highest prevalence of MRMP pneumonia, while Daejeon-Chungcheong (71.3%) showed the lowest, although the differences in prevalence were not significant (p=0.074). Co-infection of M. pneumoniae pneumonia and respiratory virus was observed in 206 patients (45.4%), and rhinovirus co-infection (101 children; 22.2%) was the most frequent. The prevalence of MRMP pneumonia with respiratory virus co-infection and the antibiotic prescriptions differed significantly among the four provinces (p < 0.05). The monthly rate of MRMP pneumonia cases among all cases of M. pneumoniae pneumonia and tetracycline or quinolone prescriptions did not differ significantly among the four regions (trend p > 0.05) during the study period. CONCLUSIONS: The prevalence of M. pneumoniae pneumonia with virus co-infection and antibiotic prescriptions could differ according to region, although the MRMP pneumonia rate showed no difference within Korea.

Breaking the language barrier: an emergentist coalition model for the origins of word learning.

How do children learn their first words? The field of language development has been polarized by responses to this question. Explanations range from constraints/principles accounts that emphasize the importance of cognitive heuristics in language acquisition, to social-pragmatic accounts that highlight the role of parent-child interaction, to associationistic accounts that highlight the role of "dumb attentional mechanisms" in word learning. In this Monograph, an alternative to these accounts is presented: the emergentist coalition theory. A hybrid view of word learning, this theory characterizes lexical acquisition as the emergent product of multiple factors, including cognitive constraints, social-pragmatic factors, and global attentional mechanisms. The model makes three assumptions: (a) that children cull from multiple inputs available for word learning at any given time, (b) that these inputs are differentially weighted over development, and (c) that children develop emergent principles of word learning, which guide subsequent word acquisition. With few exceptions, competing accounts of the word learning process have examined children who are already veteran word learners. By focusing on the very beginnings of word learning at around 12 months of age, however, it is possible to see how social and cognitive factors are coordinated in the process of vocabulary development. After presenting a new method for investigating word learning, the development of reference is used as a test case of the theory. In 12 experiments, with children ranging in age from 12 to 25 months of age, data are described that support the emergentist coalition model. This fundamentally developmental theory posits that children construct principles of word learning. As children's word learning principles emerge and develop, the character of word learning changes over the course of the 2nd year of life.

Deposition of eosinophil-granule major basic protein and expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in the mucosa of the small intestine in infants with cow's milk-sensitive enteropathy.

BACKGROUND: Cow's milk-sensitive enteropathy (CMSE) is an important cause of chronic diarrhea and failure to thrive in infancy. The immunopathology of the mucosal lesion associated with CMSE has not yet been described. OBJECTIVES: This study investigated the eosinophil activation and the role of adhesion molecules in the pathogenesis of intestinal mucosal damage associated with CMSE. METHODS: Twenty-one patients with chronic diarrhea and abnormal mucosa on duodenal biopsy specimens were included. The patients had negative responses to skin prick tests and RASTs with milk. Fourteen patients were diagnosed with CMSE by milk challenge test and were designated as the CMSE group. Seven patients with no milk intolerance were defined as the non-CMSE group. Four infants with frequent vomiting and no mucosal abnormalities were also studied as the control group. Immunohistochemical stains for eosinophil major basic protein (MBP), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 on endoscopic duodenal biopsy specimens were performed. RESULTS: The degree of eosinophil degranulation, as evidenced by localization of extracellular MBP, was significantly greater in the CMSE group compared with the non-CMSE and control groups (P <.05). Expression of VCAM-1 on mononuclear cells was higher in the CMSE group compared with the non-CMSE and control groups (P <.05). The severity of villous atrophy was positively correlated with the deposition of MBP (r = 0.79, P <.001). CONCLUSION: These results strongly suggest eosinophils and VCAM-1 are implicated in the pathogenesis of mucosal damage associated with CMSE.

Diagnosis of trichomoniasis by polymerase chain reaction.

The clinical usefulness of polymerase chain reaction (PCR) for the diagnosis of trichomoniasis was evaluated in comparison with other conventional tests. PCR was used for specific detection of Trichomonas vaginalis by primers based on the repetitive sequence cloned from T. vaginalis (TV-E650). Between June 1996 and August 1997, 426 patients visited the department of obstetrics and gynecology, Hanyang University Kuri Hospital and were examined for trichomoniasis using wet mount examination, Papanicolaou (Pap) smear, culture and PCR. One hundred and seventy-seven patients (group A) visited with the symptoms of vaginal discharge and 249 patients (group B) visited for regular cervical Pap smear with no vaginal symptoms. From group A (n = 177), 3 infections (2.0%) were detected by wet mount, 6 infections (3.3%) by Pap smear and culture, and 17 infections (10.4%) by PCR. From group B (n = 249), 4 patients (1.6%) were found to have T. vaginalis by culture and 6 infections (2.4%) were detected by PCR. Therefore, in both groups, PCR for T. vaginalis showed a higher detection rate compared with conventional wet mount, Pap smear or culture. The detection by PCR was specific for T. vaginalis since no amplification was detected with DNAs from other protozoa and Candida albicans. The sensitivity and specificity of PCR were 100%. This method could detect T. vaginalis in vaginal discharge at a concentration as low as 1 cell per PCR mixture. These results indicate that PCR could be used as a specific and sensitive diagnostic tool for human trichomoniasis.

Chemical and biological studies of a new cigarette that primarily heats tobacco. Part 1. Chemical composition of mainstream smoke.

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.

Chemical and biological studies of a new cigarette that primarily heats tobacco. Part 1. Chemical composition of mainstream smoke.

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.

Surface ultrastructure of Heterophyes nocens (Trematoda: Heterophyidae).

The surface ultrastructure of Heterophyes nocens (Trematoda: Heterophyidae) was studied by scanning electron microscopy(SEM). The adult worms were recovered from experimentally infected cats and from a naturally infected patient. They were leaf-like, ventrally concave, and ovoid or pyriform in shape. Ciliated knob-like sensory papillae (type I) were observed in single or grouped forms on and around the oral sucker, whereas non-ciliated round swellings (type II papillae) were seen on the lip of the ventral sucker. The tegumental spines around the oral sucker were 5-9 pointed, whereas those between the two suckers were 12-17 pointed. Ventrolaterally, three groups of 5-6 type I papillae were located between the oral and ventral suckers, with single ones alternating between them. The genital sucker was protruded or depressed, depending on the contraction state of the flukes, and the gonotyl spine number ranged 50-60. The number of tip points of tegumental spines was decreased posteriorly; finally they became 1-3 pointed. On the dorsal surface, 4 groups of 4-5 type I papillae were symmetrically located on both lateral sides, and the shape and distribution of tegumental spines were similar to those of the ventral surface. Although the tegumental ultrastructure of H. nocens was generally similar to those of other heterophyids, the genital sucker morphology including the number of gonotyl spines and/or the distribution pattern of tegumental spines and sensory papillae were suggested to be the characteristic features of H. nocens.

Metacercariae of Pharyngostomum cordatum found from the European grass snake, Rhabdophis tigrina, and its experimental infection to cats.

The metacercariae of Pharyngostomum cordatum were found naturally infected in the European grass snake, Rhabdophis tigrina, purchased from a local snake collector in Jinju, Kyongsangnam-do. They were experimentally fed to several kinds of animals such as mice, rats, hamsters, ducklings, a dog, and cats. The adult worms were recovered from the cats 5 weeks after the infection, but none from other animals. The measurements and other morphological characters of the metacercariae and adults were both compatible with those of P. cordatum described by previous authors. The present study confirmed that the snake, Rhabdophis tigrina, serves as a second intermediate (or paratenic) host of P. cordatum in Korea.

Analysis of flue-cured tobacco essential oil by hyphenated analytical techniques.

The major components of an alkaloid-free, flue-cured, tobacco essential oil sample are isolated and identified. This is accomplished by utilizing modern hyphenated analytical methods. The instrumentation developed to accomplish this are an automated multidimensional gas chromatograph/mass spectrometer/flame ionization detector (MDGC/MS/FID) and a multidimensional gas chromatograph/matrix isolation/Fourier transform infrared spectrometer (MDGC/MI/FTIR). A total of 306 compounds is identified in the essential oil, of which 80 are found as tobacco constituents for the first time.

Analogues of chloramphenicol: circular dichroism spectra, inhibition of ribosomal peptidyltransferase, and possible mechanism of action.

Circular dichroism spectra of series of chloramphenicol derivatives la-r were measured in water at pH 7. Compounds 1a-o exhibit two positive Cotton effects at 310--340 and 240--260 nm, respectively, and a weaker negative Cotton effect at 280--300 nm. In analogues 1c, 11, and 1m there is only a minimum between the two positive Cotton effects. Derivatives 1p--r possess a strong negative Cotton effect at ca. 280 nm. Compounds 1a--r were examined as inhibitors of the puromycin reaction with Escherichia coli 70S ribosome-poly(U)-N-AcPhe-tRNA complex. Analogues 11, 1n, lo, and lq are potent competitive inhibitors of puromycin comparable to or better than chloramphenicol (1b). Compounds 1k and 1m are less active, whereas 1d--g and 1j are only moderately effective. The rest of the analogues have marginal or no activity. The results are compared with previous biological data and discussed in terms of a retro-inverso relationship of chloramphenicol (1b) to the aminoacyl moiety of puromycin (aminoacyl-tRNA) and to a hypothetical transition state of peptide bond formation.

Ethchlorvynol: potential of metabolites for adverse effects in man.

Identification of low levels of a metabolite of unaltered skeletal structure, 1-chloro-3-ethynylpent-1-en-3,4-diol (VII), detected in biological specimens of both nonfatal and fatal poisonings with DL-1-chloro-3-ethylpent-1-en-4-yn-3-ol (ethchlorvynol, la), has been achieved by high-resolution GC/MS. Corroborative evidence for the assigned structure (VII) was provided by synthesis, the design of which included as a central objective, concurrent access to 1-chloro-3-ethynyl-3,4-epoxy-1-pentene (VI), the putative direct precursor of VII. The diastereomeric epoxide mixture (VI) is mutagenic toward Escherichia coli WP2 try-hcr-, a UV-deficient repair strain. By contrast, neither Ia, VI, nor VII proved to be mutagenic toward Salmonella typhimurium (TA98, TA100, TA1535, and TA1539) with or without a liver postmitochondrial fraction. However, the epoxides (VI) proved cytotoxic to, for example, TA100, which apparently overlies its potency as a mutagen. The cytotoxicity of VI was also apparent in an in vitro culture system.

IV. Synthesis and assay of analogs of adenosine 3',5'-diphosphate as inhibitors of bovine adrenal estrogen sulfotranferase.

Analogs of adenosine 3',5'-diphosphate are described which aid in the characterization of the inhibition of estrone sulfurylation by 3'-phosphoadenosine 5'-phosphosulfate as mediated by bovine adrenal estrogen sulfotransferase (3'-5'-phosphosulfate:estrone 3-sulphotransferase, EC 2.8.2.4). The facile conversion of ribonucleosides to 2',3'-cyclic phosphate 5'-phosphate in neat pyrophosphoryl chloride is utilized to provide a reliable route to the requisite intermediates for enzymatic regiospecific conversion to ribonucleoside 3',5'- and 2',5'-diphosphates. The importance of the 3'-phosphate ester to inhibition of estrone sulfurylation is confirmed by Ki measurements. Replacement of the 6-amino group by hydrogen or oxygen leads to considerable loss in affinity for the enzyme as does also dimethylation of the exocylic amino group. Alterations in the pyrimidine ring are not well tolerated by the sulfotransferase but modifications in the imidazole ring as in tubercidin (7 -deazaadenosine) and 8-bromoadenosine 3',5'-diphosphate lead to an enhanced affinity. The latter findings are discussed in terms of an hypothesis of stacking of the aromatic ring of the estrogen substrate and the purine moiety and its analogs.