Practical Synthesis from Streptomycin and Regioselective Partial Deprotections of (-)-(1R,2S,3R,4R,5S,6S)-1,3-Di(deamino)-1,3-diazido-2,5,6-tri-O-benzylstreptamine

We describe the gram-scale synthesis of (-)-(1R,2S,3R,4R,5S,6S)-1,3-di(diamino)-1,3-diazido-2,5,6-tri-O-benzylstreptamine from streptomycin by (i) hydrolysis of the two streptomycin guanidine residues, (ii) reprotection of the amines as azides, (iii) protection of all alcohols as benzyl ethers, and (iv) glycosidic bond cleavage with HCl in methanol. Protocols for regioselective monodebenzylation and regioselective reduction of a single azide in the product are also described, providing four optically pure building blocks for exploitation in novel aminoglycoside synthesis.

Early response cytokines and innate immunity: essential roles for TNF receptor 1 and type I IL-1 receptor during Escherichia coli pneumonia in mice

The early response cytokines, TNF and IL-1, have overlapping biologic effects that may function to propagate, amplify, and coordinate host responses to microbial challenges. To determine whether signaling from these early response cytokines is essential to orchestrating innate immune responses to intrapulmonary bacteria, the early inflammatory events induced by instillation of Escherichia coli into the lungs were compared in wild-type (WT) mice and mice deficient in both TNF receptor 1 (TNFR1) and the type I IL-1 receptor (IL1R1). Neutrophil emigration and edema accumulation induced by E. coli were significantly compromised by TNFR1/IL1R1 deficiency. Neutrophil numbers in the circulation and within alveolar septae did not differ between WT and TNFR1/IL1R1 mice, suggesting that decreased neutrophil emigration did not result from decreased sequestration or delivery of intravascular neutrophils. The nuclear translocation of NF-kappa B and the expression of the chemokine macrophage inflammatory protein-2 did not differ between WT and TNFR1/IL1R1 lungs. However, the concentration of the chemokine KC was significantly decreased in the bronchoalveolar lavage fluids of TNFR1/IL1R1 mice compared with that in WT mice. Thus, while many of the molecular and cellular responses to E. coli in the lungs did not require signaling by either TNFR1 or IL1R1, early response cytokine signaling was critical to KC expression in the pulmonary air spaces and neutrophil emigration from the alveolar septae.

Evaluating dysphagia

Dysphagia is a problem that commonly affects patients cared for by family physicians in the office, as hospital inpatients and as nursing home residents. Familiar medical problems, including cerebrovascular accidents, gastroesophageal reflux disease and medication-related side effects, often lead to complaints of dysphagia. Stroke patients are at particular risk of aspiration because of dysphagia. Classifying dysphagia as oropharyngeal, esophageal and obstructive, or neuromuscular symptom complexes leads to a successful diagnosis in 80 to 85 percent of patients. Based on the patient history and physical examination, barium esophagram and/or gastroesophageal endoscopy can confirm the diagnosis. Special studies and consultation with subspecialists can confirm difficult diagnoses and help guide treatment strategies.

Self-collection of group B Streptococcus cultures in pregnant women

OBJECTIVE

This study assesses the sensitivity of self-collected rectovaginal culture specimens for group B Streptococcus by pregnant patients.

METHODS

A volunteer sample of 240 pregnant women at 28 weeks gestation self-collected rectovaginal culture swabs to screen for the presence of group B Streptococcus. The patients' physicians collected second specimens for comparison.

RESULTS

Twenty-four of 240 women grew group B Streptococcus on at least one culture (incidence, 10%). Twenty physician-collected specimens and 19 patient-collected specimens were positive (83 and 79% sensitivity, respectively). Fifteen patients (62.5%) had both physician-collected and patient-collected cultures grow group B Streptococcus. Cohen's kappa (kappa = 0.75) indicates a high degree of agreement between patient-collected and physician-collected cultures.

CONCLUSIONS

Pregnant women are as likely as their attending physicians to obtain positive cultures for group B Streptococcus by self-collection of rectovaginal swabs.

Supine infant sleep: what do family physicians recommend?

BACKGROUND

Sudden infant death syndrome (SIDS) kills more than 6000 infants annually in the United States. Researchers have described prone sleep position as a risk factor for SIDS. A greater than 50 percent reduction in SIDS has been reported in countries where the predominant sleep position changed from prone to supine. In 1992 the American Academy of Pediatrics (AAP) recommended that healthy infants be placed in a supine position at bedtime. Previous studies of pediatric practices reported a 60 percent compliance with the recommendation. This study describes the self-reported compliance with the AAP recommendation by a cohort of family physicians.

METHODS

Three hundred members of the Uniformed Services Academy of Family Physicians were mailed a questionnaire about their recommendations regarding infant sleep position.

RESULTS

The response rate was 77 percent. Sixty-two percent of the respondents usually or always encourage supine sleep position. Twenty-one percent usually or always discourage the supine sleep position.

CONCLUSIONS

This cohort of family physicians encourages the supine sleep position at rates similar to reported cohorts of pediatricians. Reasons for the limited endorsement of the AAP recommendation were not explained by the results of this study.