Paths across generations: academic competence and aggressive behaviors in young mothers and their children

This research compared the social and cognitive development of young mothers when they were children with the social and cognitive development of their offspring. Intergenerational development was investigated over a 17-year period for 57 women who had been studied longitudinally from childhood to adulthood and who became young mothers (R. B. Cairns & B. D. Cairns, 1994). The children of these women, in turn, were followed prospectively from 1 to 2 years old through the early school years. The academic competence of mothers when they were children was significantly linked to the academic competence of their children at school age. In contrast, the across-generation correlations between measures of aggressive behavior of the mothers when they were children and measures of aggressive behavior of their children in early school grades were modest and unreliable. Certain within-generation continuities were observed in both cognitive and aggressive development.     

Cognitive screening examinations for silent cerebral infarcts in sickle cell disease

OBJECTIVE: In children with sickle cell disease (SCD), silent cerebral infarcts are the most frequent cause of neurologic injury. We determined the sensitivity and specificity of selective neurocognitive measures when separating children with silent cerebral infarcts and SCD from sibling controls. Additionally, we tested the validity of the same cognitive measures to identify patients with overt strokes. METHODS: We examined performance on a neuropsychologic battery containing measures of attention/executive, spatial, language, memory, and motor functioning for seven children with SCD and silent cerebral infarct, 21 children with SCD and overt stroke, and 17 normal siblings. Diagnosis of cerebral infarct was based on results of MRI. RESULTS: Measures from the attention and executive domains were the most useful for identifying children with silent cerebral infarct. The Test of Variables of Attention was the most robust measure and yielded a sensitivity rate of 86% and a specificity rate of 81%. This measure also showed a sensitivity rate of 95% in identifying overt stroke. CONCLUSIONS: Brief cognitive screening measures, if properly constructed, may be an effective means of identifying children with silent cerebral infarct. Future prospective studies should be pursued to assess the utility of cognitive screening for silent cerebral infarcts in SCD.     

Pediatric emergency medicine fellow clinical work requirements

A wide range of clinical requirements exists among PEM fellowship programs. Programs are equally split concerning the question of whether fellows should work with supervision or independently in the first year; a significant number of fellowship programs require continued supervision of fellows in subsequent years. Orientation for first year fellows and requirements for completion of PALS, advanced pediatric life support (APLS), ACLS, or ATLS courses prior to their first independent shift varied greatly. In particular, a minority of programs required ATLS completion even though a majority of overall fellowship programs operate in a hospital designated as a Level 1 Trauma Center. Programs in which first-year fellows worked independently had fewer attendings and were less likely to provide 24-hour coverage. Fellows appear to work a similar or less demanding schedule than PEM attendings in most fellowship programs, and most fellowship directors feel that their fellows should continue with their current schedule.     

Single-strand conformation polymorphism (SSCP)-based mutation scanning approaches to fingerprint sequence variation in ribosomal DNA of ascaridoid nematodes

In this study, we assessed single-strand conformation polymorphism (SSCP)-based approaches for their capacity to fingerprint sequence variation in ribosomal DNA (rDNA) of ascaridoid nematodes of veterinary and/or human health significance. The second internal transcribed spacer region (ITS-2) of rDNA was utilised as the target region because it is known to provide species-specific markers for this group of parasites. ITS-2 was amplified by PCR from genomic DNA derived from individual parasites and subjected to analysis. Direct SSCP analysis of amplicons from seven taxa (Toxocara vitulorum, Toxocara cati, Toxocara canis, Toxascaris leonina, Baylisascaris procyonis, Ascaris suum and Parascaris equorum) showed that the single-strand (ss) ITS-2 patterns produced allowed their unequivocal identification to species. While no variation in SSCP patterns was detected in the ITS-2 within four species for which multiple samples were available, the method allowed the direct display of four distinct sequence types of ITS-2 among individual worms of T. cati. Comparison of SSCP/sequencing with the methods of dideoxy fingerprinting (ddF) and restriction endonuclease fingerprinting (REF) revealed that also ddF allowed the definition of the four sequence types, whereas REF displayed three of four. The findings indicate the usefulness of the SSCP-based approaches for the identification of ascaridoid nematodes to species, the direct display of sequence variation in rDNA and the detection of population variation. The ability to fingerprint microheterogeneity in ITS-2 rDNA using such approaches also has implications for studying fundamental aspects relating to mutational change in rDNA.     

The arabidopsis ACT7 actin gene is expressed in rapidly developing tissues and responds to several external stimuli

ACT7 encodes one of the six distinct and ancient subclasses of actin protein in the complex Arabidopsis actin gene family. We determined the sequence and structure of the Arabidopsis thaliana ACT7 actin gene and investigated its tissue-specific expression and regulation. The ACT7 mRNA levels varied by 128-fold among several different tissues and organs. The highest levels of aCT7 mRNA were found in rapidly expanding vegetative organs, the lowest in pollen. A translational fusion with the 5' end of ACT 7 (1.9 kb) joined to the beta-glucuronidase reporter gene was strongly and preferentially expressed in all young, developing vegetative tissues of transgenic Arabidopsis plants. ACT7 was the only Arabidopsis actin gene strongly expressed in the hypocotyl and seed coat. Although no beta-glucuronidase expression was seen in developing ovules or immature seeds, strong expression was seen in dry seeds and immediately after imbibition in the entire seedling. ACT7 was the only Arabidopsis actin gene to respond strongly to auxin, other hormone treatments, light regime, and wounding, and may be the primary actin gene responding to external stimuli. The ACT7 promoter sequence contains a remarkable number of motifs with sequence similarity to putative phytohormone response elements.     

A method for radiologic-assisted gastrostomy when percutaneous endoscopic gastrostomy is contraindicated

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) has been established as a faster and safer procedure than open surgical gastrostomy. It cannot be done, however, for many patients with partially obstructing pharyngeal or esophageal carcinoma, previous gastrectomy, upper abdominal surgery, or bowel distension from distal obstruction. PATIENTS AND METHODS: We attempted percutaneous radiologic-assisted gastrostomy (RAG) in 231 patients referred for gastrostomy, 38 of whom had a relative contraindication for PEG. The procedure involves passing, under radiologic guidance, an orogastric inflation tube that contains a snare. We used a 5-inch long, 18-gauge needle to transabdominally insert a wire into the stomach, avoiding loops of bowel visualized by air contrast. Retrieving the transabdominal wire by snare allowed retrograde passage of the gastrostomy tube as done in standard PEG. RESULTS: The procedure was successful in 230 of 231 cases, including 37 of the 38 patients with contraindications. We could not gain gastric access in 1 patient with a 75% gastrectomy. Overall, 6 patients developed complications and 1 died. There was no procedure-related morbidity or mortality in the patients with contraindications to PEG who underwent successful RAG. Subsequent laparotomy indicated tube passage through the liver in 2 of these cases and small bowel mesentery in 1 case without clinical problems. We performed a percutaneous jejunostomy in the efferent limb of the gastrojejunostomy in 1 patient with a previous gastrectomy. CONCLUSION: The snare technique is simpler and faster than the usual radiologic gastropexy technique, and safer than an endoscopic procedure. It has become our procedure of choice for gaining gastric access.     

Modified phacoemulsification in situ

We describe a phacoemulsification technique for cataracts in eyes with anticipated weak zonular apparatus. After central sculpting, a crater 90% deep is made. A horizontal fracture is created with the phaco probe and chopper. The nucleus is chopped, dividing the inferior hemisection into 2 pie-shaped pieces, which are then emulsified. Without rotating the nucleus, a groove is made at the superior hemisection and a vertical fracture created with the chopper. The bevel of the phaco probe is then turned down to emulsify each quadrant separately. This technique is especially useful in eyes with weakened zonular apparatus such as those with hypermature cataract, uveitis, long-standing glaucoma, trauma, retinitis pigmentosa, and operated retinal detachments.     

Direction determination in the minus-end-directed kinesin motor ncd

Motor proteins of the kinesin superfamily transport intracellular cargo along microtubules. Although different kinesin proteins share 30-50% amino-acid identity in their motor catalytic cores, some move to the plus end of microtubules whereas others travel in the opposite direction. Crystal structures of the catalytic cores of conventional kinesin (a plus-end-directed motor involved in organelle transport) and ncd (a minus-end-directed motor involved in chromosome segregation) are nearly identical; therefore, the structural basis for their opposite directions of movement is unknown. Here we show that the ncd 'neck' made up of 13 class-specific residues next to the superfamily-conserved catalytic core, is essential for minus-end-directed motility, as mutagenesis of these neck residues reverses the direction of ncd motion. By solving the 2.5 A structure of a functional ncd dimer, we show that the ncd neck (a coiled-coil) differs from the corresponding region in the kinesin neck (an interrupted beta-strand), although both necks interact with similar elements in the catalytic cores. The distinct neck architectures also confer different symmetries to the ncd and kinesin dimers and position these motors with appropriate directional bias on the microtubule.