Decompression of multiple pneumatoceles in a premature infant by percutaneous catheter placement.

Pneumatoceles due to acquired localized overinflation as a form of pulmonary interstitial emphysema are complications of advanced bronchopulmonary dysplasia. Different ventilation modes, selective bronchial intubation, balloon obstruction of the affected bronchus and steroids have been reported with success. Lobectomy has also been used. We present a premature infant with multiple large pneumatoceles causing respiratory compromise. In our case percutaneous decompression under fluoroscopy guidance resulted in a permanent cure.

A comparison of the Mogen and Gomco clamps in combination with dorsal penile nerve block in minimizing the pain of neonatal circumcision.

OBJECTIVES: 1) To compare the Mogen and Gomco clamps with regard to pain experienced during neonatal circumcision, and 2) to assess neonatal circumcision pain with and without dorsal penile nerve block (DPNB). DESIGN/METHODS: A randomized, controlled, nonblinded clinical trial; 48 healthy, full-term infants were randomized into one of the following four groups: Gomco vs Mogen with (+) or without (-) DPNB. DPNB+ infants were injected with 0.8 mL of 1% lidocaine before circumcision. DPNB- infants received no placebo injection. Heart rate, respiratory rate, and oxygen saturation (SaO2) during the procedure were monitored and data transferred to computer files by using the Datalab software system. Crying was recorded on videotape. Pre- and postcircumcision saliva samples for cortisol analysis were collected. Heart rate, respiratory rate, SaO2, cortisol changes, and duration of crying were evaluated statistically with two-way analyses of variance and t tests. RESULTS: The type of clamp but not the use of anesthesia was significantly associated with the length of the procedure (mean Mogen time, 81 seconds; mean Gomco time, 209 seconds) and percentage of respiratory rate change. The use of anesthesia but not the type of clamp was significantly associated with percentage of crying time and percentage of SaO2 change during the procedure. Heart rate changes and total crying time were significantly associated with both the type of clamp and the use of anesthesia. Neither clamp type nor anesthesia status was significantly associated with salivary cortisol changes, although the mean increase for the DPNB- group was approximately twice that for the DPNB+ group. Fifty-six percent of infants circumcised with the Mogen clamp and DPNB did not cry at all during the procedure. CONCLUSIONS: DPNB is effective in reducing neonatal circumcision pain with either the Mogen or the Gomco clamp. For a given anesthesia condition, the Mogen clamp is associated with a less painful procedure than the Gomco. The Mogen clamp with DPNB causes the least discomfort during neonatal circumcision.

Functional dissection of yeast Hir1p, a WD repeat-containing transcriptional corepressor.

The HIR1 gene product is required to repress transcription of three of the four histone gene loci in Saccharomyces cerivisiae, and like its counterpart, the HIR2 protein, it functions as a transcriptional corepressor. Although Hir1p and Hir2p are physically associated in yeast, Hir1p is able to function independently of Hir2p when it is artificially recruited to the histone HTA1 promoter. A deletion analysis of HIR1 has revealed two separate repression domains: one in its N terminus, where seven copies of the beta-transducin or WD40 motif reside, and the second in the remaining C-terminal amino acids. Overexpression of the WD repeats in a hir1delta strain complemented its Hir- phenotype, while overexpression of the C terminus in a wild-type strain caused both Hir- and Spt- phenotypes. The Hir1p C terminus physically interacted in vivo with Hir2p, and both Hir1p repression domains interacted with full-length Hir1p. It was additionally found that the Hir1p WD repeats functionally interacted with the SPT4, SPT5, and SPT6 gene products, suggesting that these repeats may direct Hir1p to different protein complexes.

Hir1p and Hir2p function as transcriptional corepressors to regulate histone gene transcription in the Saccharomyces cerevisiae cell cycle.

The HIR/HPC (histone regulation/histone periodic control) negative regulators play important roles in the transcription of six of the eight core histone genes during the Saccharomyces cerevisiae cell cycle. The phenotypes of hir1 and hir2 mutants suggested that the wild-type HIR1 and HIR2 genes encode transcriptional repressors that function in the absence of direct DNA binding. When Hir1p and Hir2p were artificially tethered to yeast promoters, each protein repressed transcription, suggesting that they represent a new class of transcriptional corepressors. The two proteins might function as a complex in vivo: Hir2p required both Hir1p and another Hir protein, Hir3p, to repress transcription when it was tethered to an HTA1-lacZ reporter gene, and Hir1p and Hir2p could be coimmunoprecipitated from yeast cell extracts. Tethered Hir1p also directed the periodic transcription of the HTA1 gene and repressed HTA1 transcription in response to two cell cycle regulatory signals. Thus, it represents the first example of a transcriptional corepressor with a direct role in cell cycle-regulated transcription.

Initial hepatic removal of chylomicron remnants is unaffected but endocytosis is delayed in mice lacking the low density lipoprotein receptor.

Two endocytic receptors, the low density lipoprotein (LDL) receptor (LDLR) and the LDLR-related protein (LRP), are thought to act in concert in the hepatic uptake of partially metabolized dietary lipoproteins, the chylomicron remnants. We have evaluated the role of these two receptors in the hepatic metabolism of chylomicron remnants in normal mice and in LDLR-deficient [LDLR (-/-)] mice. The rate of chylomicron remnant removal by the liver was normal up to 30 min after intravenous injection of chylomicrons into LDLR (-/-) mice and was unaffected by receptor-associated protein (RAP), a potent inhibitor of ligand binding to LRP. In contrast, endocytosis of the remnants by the hepatocytes, measured by their accumulation in the endosomal fraction and by the rate of hydrolysis of component cholesteryl esters, was dramatically reduced in the absence of the LDLR. Coadministration of RAP prevented the continuing hepatic removal of chylomicron remnants in LDL (-/-) mice after 30 min, consistent with blockade of the slow endocytosis by a RAP-sensitive process. Taken together with previous studies, our results are consistent with a model in which the initial hepatic removal of chylomicron remnants is primarily mediated by mechanisms that do not include LDLR or LRP, possibly involving glycosaminoglycan-bound hepatic lipase and apolipoprotein E. After the remnants bind to these alternative sites on the hepatocyte surface, endocytosis is predominantly mediated by the LDLR and also by a slower and less efficient backup process that is RAP sensitive and therefore most likely involves LRP.

Intracellular processing of apolipoprotein J precursor to the mature heterodimer.

Circulating apolipoprotein J (apoJ) is a 70 kDa glycoprotein comprised of disulfide-linked alpha and beta subunits derived from a single precursor. Post-translational modifications that occur prior to apoJ secretion were assessed, with specific focus on carbohydrate type, the timing of proteolytic cleavage, and the importance of glycosylation on the cleavage and secretion processes. ApoJ was initially resolved as a single chain, intracellular precursor of 58 kDa which contained N-linked oligosaccharide but no O-linked oligosaccharide. The precursor was converted to an intracellular 70 kDa glycoprotein, which became the major intracellular form of apoJ prior to secretion. Maturation of the 58 kDa precursor involved conversion of high-mannose carbohydrate to complex-type carbohydrate containing sialic acid, as well as intracellular cleavage to yield alpha and beta subunits. This cleavage event occurred at a late stage of carbohydrate modification, most likely in the trans-Golgi or a post-Golgi compartment. The maturation and secretion of apoJ occurred rapidly, with a half-time of 30-35 min. Tunicamycin treatment of cells resulted in an unglycosylated doublet comprised of one single chain and one cleaved form of apoJ. The unglycosylated apoJ species were secreted rapidly with a half-time of 20 min. Both cleavage and secretion were independent of glycosylation.

Umbilical artery catheter position and intraventricular hemorrhage.

A historical cohort study was designed to examine high (T6-T11) versus low (L3-L5) umbilical artery catheter (UAC) positioning as a risk factor for subependymal/intraventricular hemorrhage (SEH/IVH) in very low birthweight infants. High and low UAC groups were similar for mode of delivery, severity of pulmonary disease, weight, gestation, Apgar scores, and air leak. Seventeen of 36 infants with high UACs and 6 of 44 infants with low UACs developed SEH/IVH. The incidence (P less than .001) and severity (P less than .01) of SEH/IVH was significantly greater in the high UAC positioning group. Retrograde arterial flow with or without embolization to the cerebral circulation from high UAC positioning is suggested as a possible cause for the association between high UAC positioning and SEH/IVH.

Erb's palsy and fetal bruising after external cephalic version: case report.

An unusual fetal complication, Erb's palsy and fetal bruising, after successful external cephalic version is reported. Importance of fetal weight estimation prior to the attempts to perform a version is stressed.

An epidemic of resistant Salmonella in a nursery. Animal-to-human spread.

A Salmonella heidelberg epidemic in a hospital nursery was traced to infected calves on a dairy farm where the mother of the index patient lived. The Salmonella isolates from all cases were resistant to chloramphenicol, sulfamethoxazole, and tetracycline. Verification of the spread of infection from the farm animals to a hospital population is unusual and raises questions about the hazards of antibiotic animal-feed preparations that may induce infection with resistant organisms in humans.