Many biological processes depend on the function of proteins that detect changes in a cell's environment and transmit the information to the cytoplasm, for example, peptide hormone receptors. In Escherichia coli this class of proteins is exemplified by the sensory transducers (also called signalling proteins or methyl-accepting chemotaxis proteins) which have a central role in mediating chemotactic behaviour. The sensory transducers are the products of four genes: tsr, tar, tap and trg. Each transducer detects changes in the environmental concentration of one or a very few attractants: Tsr, serine; Tar, aspartate and maltose; Tap, unknown; and Trg, ribose and galactose. Tsr and Tar act directly as chemoreceptors for the amino acid attractants and signal changes in their degree of occupancy to the flagellar apparatus. Detection of these changes in occupancy is made possible as the transducers are methylated at multiple glutamate residues such that their level of methylation reflects the most recent chemoeffector concentration. Biochemical and genetic information concerning the serine transducer protein has been accumulating rapidly but little is known about the structure of the molecule. We present here the nucleotide sequence of the tsr gene of E. coli; the amino acid sequence derived from it suggests that the Tsr transducer protein has a relatively simple transmembrane structure that may place limits on the mechanisms available for the transmission of sensory information into the cell.

Amino Acid Sequence↗

PubMedDate not supplied

Successful treatment of infantile hemangiomas with interferon-alpha-2b.

PURPOSE: Hemangiomas are benign tumors occurring in 10% of infants. A small percentage are complicated by blockage of vital structures, consumptive coagulopathy, or heart failure, resulting in a mortality of -20% of patients with complications. Here, we describe four infants with complicated hemangiomas responding to interferon-alpha-2b therapy. PATIENTS AND METHODS: Four children with hemangiomas were treated with interferon-alpha-2b for complicating heart failure (1), visual impairment (2), or coagulopathy (1). Patients received interferon-alpha-2b alone or in conjunction with corticosteroid therapy over 2 to 9 months. Imaging studies and urinary basic fibroblast growth factor (bFGF) levels were used to monitor treatment response. RESULTS: Three of four patients demonstrated involution of the hemangiomas with improvement in their coagulopathy or visual impairment. The fourth patient expired due to cardiac complications despite radiologic evidence of hemangioma involution. Side effects associated with interferon-alpha-2b treatment included elevated transaminases (2) and leukocytosis (2), which resolved upon completion of therapy. One patient developed mild gross motor delay (1), which improved after cessation of therapy. Decreased urinary bFGF levels correlated with hemangioma involution. CONCLUSION: Interferon-alpha-2b therapy is an effective, well-tolerated treatment for complicated hemangiomas. Measurement of urinary bFGF levels may provide an objective method for monitoring treatment response.

Exophthalmos↗

PubMedDate not supplied

Roentgenographic parameters of the normal infant hip.

Multiple parameters of hip development were analyzed in 100 children at 3, 6, 9, and 12 months. The acetabular index decreased from 25 degrees in girls and 22 degrees in boys at 3 months to 18 and 19 degrees, respectively, at 24 months. H distance did not vary with age or sex, but D distance increased with increasing age. Measurement of the medial gap was found to be highly variable. Asynchronous appearance of the secondary ossification centers occurred in eight children and was not associated with subsequent abnormal hip joint development. The true acetabular teardrop is not consistently present in these age ranges. The center edge angle increases with age. Shenton's line was difficult to measure and not reproducible.

Acetabulum↗

PubMedDate not supplied

Thoracic versus lumbar administration of epidural morphine for postoperative analgesia after thoracotomy.

BACKGROUND AND OBJECTIVES: The purpose of this study was to compare the effects of thoracic and lumbar epidural morphine on pulmonary function and analgesia after thoracotomy for pulmonary resection. METHODS: Twenty-seven patients were randomized into two groups to receive either thoracic or lumbar epidural morphine as needed for postoperative analgesia. Postoperative pain was assessed hourly on a 10-cm visual analog scale (VAS), and epidural morphine was administered in 3 mg doses for a VAS score > 2 cm. Patients underwent pulmonary function tests (forced vital capacity, forced expiratory volume at 1 second, peak expiratory flow) preoperatively, and 24 hours postoperatively. Results were expressed as mean +/- 1 SE and analyzed using Student's t-test and Student-Newman-Keuls test at p < 0.05. RESULTS: Twenty patients completed the study (n = 10 per group). Patients in the thoracic group required 3.1 +/- 0.4 injections to a total morphine dose of 11.9 +/- 1.4 mg during the first 24 hours postoperatively, and those in the lumbar group required 4.7 +/- 0.4 doses to a total 24-hour morphine dose of 16.4 +/- 1.2 mg (p < 0.05). Median hourly VAS scores were similar in both groups. Postoperative pulmonary function decreased in both groups without intergroup differences. CONCLUSIONS: The authors conclude that thoracic epidural morphine administration in patients after thoracotomy results in decreased morphine requirements and the same degree of analgesia as does lumbar administration.

Aged↗