Poly (A) binding protein is bound to both stored and polysomal mRNAs in the mammalian testis

RNA-binding proteins that bind to the 3' untranslated region of mRNAs play important roles in regulating gene expression. Here we examine the association between the 70 kDa poly (A) binding protein (PABP) and stored (RNP) and polysomal mRNAs during mammalian male germ cell development. PABP mRNA levels increase as germ cells enter meiosis, reaching a maximum in the early postmeiotic stages, and decreasing to a nearly nondetectable level towards the end of spermatogenesis. Most of the PABP mRNA is found in the nonpolysomal fractions of postmitochondrial extracts, suggesting that PABP mRNA is either inefficiently translated or stored as RNPs during spermatogenesis. Virtually all of the testicular PABP is bound to either polysomal or nonpolysomal mRNAs, with little, if any, free PABP detectable. Analysis of several specific mRNAs reveals PABP is bound to both stored (RNP) and translated forms of the mRNAs. Western blot analysis and immunocytochemistry indicate PABP is widespread in the mammalian testis, with maximal amounts detected in postmeiotic round spermatids. The presence of PABP in elongating spermatids, a cell type in which PABP mRNA is nearly absent, suggests that PABP is a stable protein in the later stages of male germ cell development. The high level of testicular PABP in round spermatids and in mRNPs suggests a role for PABP in the storage as well as in the subsequent translation of developmentally regulated mRNAs in the mammalian testis.

Stereotactic Gamma Knife radiosurgery for the treatment of dystonia

A case of dystonia treated with Gamma Knife radiosurgery is reported. A 37-year-old female patient had a history of tuberculous meningitis at the age of 10 and subsequently developed a left hemidystonia. MRI showed an old infarction in the right caudate nucleus, globus pallidus and putamen. Stereotactic Gamma Knife radiosurgery was employed to make a lesion in the right posteroventral globus pallidus. Postoperatively, the patient's condition improved. However, homonymous hemianopsia developed postoperatively.

Cerebral energy metabolism following ESWL brain injury model and effects of cerebral protective drugs

The goal of this study was to introduce a new method inducing an experimental brain injury model using ESWL(Extracorporeal Shock Wave Lithotripsy) and to evaluate findings of localized lesions on 1H MR imaging and the response of cerebral energy metabolism using a 31P MR spectroscope to the ESWL brain injury in cats. This study also examined effects of cerebral protective drugs. 1) There were no statistically significant changes in pH at all measurement points. 2) In the trauma group, initial decrease of PCr/Pi was seen at 30 to 60 minutes with return to control levels by 2 hours after injury(P < 0.05), followed by a second decline at 4 hours which lasted until 8 hours after injury. 3) Significant recovery in PCr/Pi(P < 0.05) was observed in both the THAM and dexamethasone treated groups at all measurement points and in the mannitol treated group only temporary recovery at 30 and 60 minutes (P < 0.05). 4) High intensity signals were seen on 1H MR imaging in traumatized animals. This study demonstrated the immediate and persistent recovery of cerebral energy metabolism using THAM or dexamethasone and an immediate but transient effect with mannitol in traumatized animals.

Induction of motor neuron sprouting in vivo by ciliary neurotrophic factor and basic fibroblast growth factor

Ciliary neurotrophic factor (CNTF) and basic fibroblast growth factor (bFGF) were tested for effects on sprouting by motor neurons innervating the adult mouse gluteus muscle. Factors were delivered by subcutaneous injection directly over the surface of the superior gluteus muscle once daily for 7 d and then end plates and axons were visualized by combined silver and cholinesterase staining. CNTF (500 ng daily) induced sprouting both from end plates and from the subset of nodes of Ranvier that are closest to the end plate. The effect of CNTF was potentiated twofold by coadministration of bFGF at doses of 2-20 ng daily, whereas treatment with bFGF alone failed to induce sprouting from either end plates or nodes of Ranvier. The sprouting stimulus delivered by the factors showed limited penetrance into the muscle and restricted lateral spread from the injection site.

Korean children's understanding of multidigit addition and subtraction

This study examined Korean second and third graders' understanding of multidigit addition and subtraction and particularly their ability to explain the trading required when a column sum of the addends is 10 or more. 72 middle-class second- and third-grade children (aged 7-4 to 8-4 and 8-4 to 9-4, respectively, at the time of the midyear interview) attending 2 schools in Seoul, Korea, were asked to solve 2- and 3-digit problems given in vertical form and then were individually interviewed about their conceptual understanding of such problems. Even though the second graders had not yet received instruction in school on 3-digit problems, children in both grades were quite accurate solvers of the multidigit addition and subtraction problems and demonstrated knowledge of the place-value names "ten" and "hundred." Every child also correctly identified the trade between the ones and tens columns as a traded ten. Most of the third graders identified the 1 written in the hundreds column on the addition problems as a hundred, but half of the second graders identified it as a ten. Most of the third graders also gave correct descriptions of the trading (regrouping, borrowing) required by a 3-digit subtraction problem with 2 zeros in the top number. Children used 3 different conceptual structures in discussing the already-solved problems: a multiunit quantities structure, a regular one/ten trades structure, and a combination of these two. These results are compared to the literature on the performance and conceptual structures of children in the United States.

Characteristics of liquid crystal devices with improved response times

The response time and contrast are reported for a liquid crystal (LC) cell operated in the transmission mode. The cell yielded improved response times (e.g., of the order of 0.15 msec) that result from several features: (1) the LC material is a mixture of cholesteryl nonanoate, p-cyanophenyl p-butylbenzoate, and p-cyanophenyl p-heptylbenzoate in the weight ratio x:100:230, respectively; and (2) the cell is operated with the signal drive voltage superimposed on a low-frequency square-wave pedestal voltage. The influence of electrode surface treatment is discussed, and it is postulated that the rapid response time results from only the thin layer of LC material adjacent to the treated electrode surface.