Congenital middle-ear deafness: CT study

Computed tomography (CT) was used to study 25 patients with congenital conductive hearing loss and normal external auditory canals. Deformities were subdivided according to ossicular, fenestral, and cholesteatomatous origin. Isolated ossicular deformities were found in 14 patients (five bilateral), cholesteatoma in eight, oval-window nondevelopment (with ossicular deformity) in one, and normal studies in two (congenital stapes fixation at the level of the annular ligament). Ossicular deformities may be subdivided into incudostapedial disconnections into incudostapedial disconnections (most common), malleoincudal fixations, and stapes fixations. Most are due to developmental anomaly of the first or second branchial arch. The stapes has a dual origin (second arch and otic capsule). A cholesteatoma is defined as congenital only if there is no history of otitis and the tympanic membrane is intact. In this series, six were in the middle ear proper, and two were within the attic beyond otoscopic view. Their CT appearance, with one exception, was essentially identical to that of acquired lesions.     

小鼠颅神经嵴细胞的培养和特征

目的：在体外原代培养Balb/c小鼠胚胎的颅神经嵴细胞。为颅面部各种组织细胞的发育研究提供细胞来源。方法：采用胰酶消化法分离小鼠胚胎第8.5天的颅神经管，从小鼠颅神经管中游离出来的细胞即为颅神经嵴细胞，用免疫组织化学方法鉴定细胞的来源，并测定细胞的生长曲线。结果：成功地培养出小鼠的颅神经嵴细胞，其形态类似成纤维样细胞，免疫组化检测结果表明，神经特异性烯醇化酶（NSE）抗体染色结果阳性。细胞的群体倍增时间为43.65h。结论：原代培养的小鼠颅神经嵴细胞生长稳定，来源明确，是颅面部各种细胞的发育和分化研究中一种有用的工具。     

Hemagglutination inhibition of Cromer blood group antibodies with soluble recombinant decay-accelerating factor

BACKGROUND: Cromer blood group antigens are located on decay- accelerating factor (DAF, CD55), which contains four short consensus repeats (SCRs). Cromer system antibodies may be of clinical significance in blood transfusion. STUDY DESIGN AND METHODS: Soluble recombinant DAF (srDAF) constructs, consisting of all four SCRs or of only two SCRs, were expressed in the yeast Pichia pastoris. They are used in hemagglutination-inhibition tests with Cromer system antibodies and with DAF-specific monoclonal antibodies. RESULTS: The srDAF inhibited hemagglutination by all Cromer system alloantibodies in undiluted serum. Antibodies to antigens of other blood group systems were not inhibited by the srDAF. Hemagglutination-inhibition tests with domain-deleted srDAF showed that UMC is on SCR-4 and confirmed that Tca, TcaTcb, and WESb are on SCR-1; Dra is on SCR-3; and Cra is on SCR- 4. CONCLUSIONS: Hemagglutination inhibition with srDAF is useful in the recognition of antibodies that belong to the Cromer blood group system and facilitates pretransfusion testing. This use of domain-deleted srDAF provides an easy method of determining epitope location on DAF and is an aid to more precise identification of Cromer system antibodies.     

Superior mesenteric artery blood flow velocity and estimated volume flow: duplex Doppler US study of preterm and term neonates

To obtain information about intestinal hemodynamics of healthy neonates, the authors assessed velocity and volume of blood flow with duplex Doppler sonography in the superior mesenteric artery (SMA) in 91 stable preterm and term neonates. Blood flow velocity in the SMA and estimated volume blood flow increased linearly with gestational age and increasing body weight. The mean estimated volume blood flow (+/- standard deviation) was 43 mL/kg/min +/- 13 and did not depend on differences in body weight. The authors also assessed blood flow velocity in the SMA and volume blood flow in 18 infants with conditions that may affect blood supply to the bowel. Twelve infants who were small for gestational age appeared to have an abnormally low resistance of the vascular bed of the SMA during the 1st days of life, as compared with stable appropriate-for-gestational-age infants matched for gestational age. Three of six term neonates with cardiovascular abnormalities had left ventricular outflow obstruction and an abnormal blood flow velocity waveform of the SMA, suggesting a decrease in blood supply to the bowel. The results of this study may help in evaluations of intestinal perfusion in infants with abnormal conditions.     

Innervation of the urinary bladder in higher primates

Stimulating electrodes were placed on the terminal branches of the pelvic nerves to the urinary bladder and the pudendal nerve to the sphincters in seven Rhesus monkeys and two chimpanzees. The proximity of the electrodes to these structures assured organ specificity. Evoked responses produced by stimulation of these terminal nerve branches were recorded in the fascicles and rootlets of the lower thoracic, lumbar, and sacral nerve roots. During identifical stimulating and recording conditions, the amplitude as well as presence or absence of the evoked responses recorded was variable within the various roots. The amplitude of the evoked responses or their absence depended on the number of fibers within a particular fascicle which conducted impulses to the urinary bladder or the urethral and anal sphincters. By this method, it was determined that there was segregation or compartmentalization of the nervous innervation to the urinary bladder and sphincters within the spinal roots. In addition, the segmental spinal cord origin of the innervation of the urinary bladder was determined for the Rhesus monkey and chimpanzee. In the Rhesus monkey, the pelvic nerves to the urinary bladder arose from the first and second sacral segments and to a much lesser extent from the seventh lumbar segment. In the chimpanzee the sacral segments one to four gave rise to innervation of the urinary bladder.