Four new genotypes of adenovirus type 3 isolated from patients with conjunctivitis in Japan.

Adenovirus type 3 (Ad3) was the most frequently isolated serotype from patients with conjunctivitis during the period from 1989 to 1991 in Japan. All Ad3 strains isolated in 1990 had an identical genotype, Ad3f. However, in 1992, the predominant serotype was replaced by Ad4. The genome type was examined to determine whether genetic changes existed in Ad3 isolates in 1992. Ad3 isolated from 55 patients with acute conjunctivitis during the period from June 1992 to February 1993 in Japan was assessed by genome typing with restriction endonucleases BamH I, Bgl II, Hind III, and Sma I recognizing 6-base-pair sequences. The emergence of four new genotypes of Ad3 was identified; one with a new Bam HI site (one isolate), one with a new Bgl II site (two isolates), one with a new Hind III site (three isolates) and one with a new Sma I site (two isolates). This study demonstrates that the emergence of a new genotype of Ad3 may contribute to the replacement of the predominant serotype associated with adenovirus conjunctivitis in Japan.     

Polygon interpolation for serial cross sections

In this paper, a new technique for contour interpolation between slices is presented. We assumed that contour interpolation is equivalent to the interpolation of a polygon that approximates the object shape. The location of each polygon vertex is characterized by a set of parameters. Polygon interpolation can be performed on these parameters. These interpolated parameters are then used to reconstruct the vertices of the new polygon. Finally, the contour is approximated from this polygon using a cubic spline interpolation. This new technique takes into account the shape, the translation, the size, and the orientation of the object's contours. A comparison with regular shape-based interpolation is made on several object contours. The preliminary results show that this new method yields a better contour and is computationally more efficient than shape-based interpolation. This technique can be applied to gray-level images too. The interpolation result of an MR image does not show artifact of intermediate substance commonly seen in a typical linear gray-level interpolation.     

Bioinspired Photo‐Core‐Crosslinked and Noncovalently Connected Micelles From Functionalized Polystyrene and Poly(ethylene oxide) Homopolymers

In this paper, we report a simple and effective method for the preparation of stable core‐crosslinked micelles after the self‐assembly of thymine‐functionalized polystyrene (PVBT) and adenine‐terminated poly(ethylene oxide) (PEO‐A) homopolymers, and subsequent bioinspired photo‐crosslinking of the thymine units in PVBT. We obtained “graft‐like” copolymers from the interactions of PEO‐A with the PVBT chains through complementary multiple hydrogen bonding in a common solvent (dimethylformamide) after the addition of selective solvents (H₂O and MeCN for PVBT and PEO‐A, respectively). Stable micelles featuring PVBT as the core and PEO‐A as the shell were formed via selective solvent pairs; they were clearly visualized using transmission electronic microscopy and staining techniques. The shapes and sizes of the core/shell micelle structures did not change after exposure to UV light, revealing the enhanced dimensional stability of these photo‐core‐crosslinked micelles.     

Use of the Optomap with lid retraction and its sensitivity and specificity#

Background: Optomap uses the ultra‐wide field scanning laser ophthalmoscopy to provide retinal examination. It permits fundus examination without the use of a mydriatic, which is more comfortable for the patients. This paper determines the sensitivity and specificity of the Optomap for detecting retinal signs under non‐mydriatic conditions. Methods: Fifty‐four eyes identified with retinal/choroidal signs and eight normal eyes were recruited from 31 Hong Kong Chinese subjects. Photo‐documentation of fundal changes was obtained with the Optomap under non‐mydriatic conditions before a dilated fundus examination by a clinician using standard procedures. The eyelid was retracted using a cotton bud when necessary. Dilated fundus examinations were performed by another clinician using binocular indirect ophthalmoscopy and slitlamp biomicroscopy with a fundus lens. The Optomap images were evaluated by four other investigators under masked condition. The International Classification of Disease, Ninth Revision (ICD‐9‐CM) was adopted for recording retinal features. Screening results were compared with those obtained using the dilated fundus examination as the gold standard. Results: The cotton bud method for eyelid retraction showed an improvement in the area of retina that could be visualised. The sensitivity and specificity of the Optomap averaged 76.4 and 71.9 per cent, respectively. Some fundal signs were missed by all observers in the Optomap but not with the biomicroscope. These included white‐without‐pressure, lattice degeneration, paramacular drusen and pigmentary changes at central fundus. Conclusion: Optomap serves as a reliable screening tool for fundus examination especially because it covers a much wider area of the peripheral retina than other digital instruments for fundus photography.     

Down-regulation of von Hippel-Lindau protein in N-nitroso compound-induced rat non-clear cell renal tumors

Non-clear cell rat kidney tumors, inducible by N-nitroso compounds but lacking mutations in the von Hippel--Lindau (VHL) coding sequence, were examined for other VHL alterations. Neither mutations nor DNA methylation was detected in a putative promoter region. By immunohistochemistry, however, VHL protein level was evidently reduced in six of the eight eosinophilic renal epithelial tumors and in all the ten nephroblastomas. Immunoblotting of normal kidney detected two VHL proteins of 20 and 22kDa in a 16-day-old fetal rat but only 20kDa protein in an adult rat. This is the first demonstration of VHL alteration at the protein level.     

Early expression of thyroid hormone deiodinases and receptors in human fetal cerebral cortex

Thyroid hormones are known to be important for optimal development of the human central nervous system. Classically, maternal thyroid hormones have not been thought to have a major role in defining central nervous system development. However, recent epidemiological evidence has indicated that subtle deficiencies in circulating maternal thyroid hormones in the first trimester of pregnancy are associated with adverse neurodevelopment. We have used real time PCR to quantitate the expression of mRNAs encoding the thyroid receptor isoforms (TR alpha1, alpha2, beta1 and beta2) and thyronine deiodinase subtypes (5'-DI, 5'-DII and 5-DIII) in human fetal cerebral cortex from the first and second trimesters of pregnancy. Deiodinase subtype activities have also been determined in these tissues and compared to 'normal' adult human cerebral cortex. Iodothyronine deiodinase mRNAs were expressed in human fetal cerebral cortex from 7 to 8 weeks of gestation. The expression of 5'-DI mRNA was variable in fetal life but increased relative to adult cortex (P<0.05), whereas the activity of this enzyme was below the level of assay detection. 5'-DII mRNA and activity in fetal cerebral cortex was detectable from as early as 7-8 weeks but not significantly different from that in adult life except at 15-16 weeks when mRNA expression increased (P<0.05). Fetal cortex 5-DIII mRNA expression was present from the early first trimester but less abundant than in adult tissue (P<0.01) and 5-DIII activity appeared greater in fetal cortex (P<0.01) as compared to adults. Only TR alpha1 mRNA was more abundantly expressed in fetal cortex than adult tissues (P<0.01). In contrast, the TR isoforms (alpha2 and beta1) were expressed significantly less than in adult tissues (P<0.05). Only 26% of fetal cerebral cortex samples expressed TR beta 1. There is evidence that the developing fetal brain, as early as the first trimester, expresses TRs and exhibits the mechanisms of pre-receptor control of thyroid hormone supply.     

Ki-ras and the characteristics of mouse lung tumors

Codon 12 mutations are frequent in the Ki-ras oncogene in human lung adenocarcinomas, but the effects of these alterations have not been well characterized in lung epithelial cells. Murine primary lung tumors derived from peripheral epithelial cells also may present Ki-ras mutations and are useful models for study of early phases of tumor development. One hypothesis is that Ki-ras mutation and/or a Ki-ras p21 increase could enhance Ki-ras p21-GTP and cell-cycle stimulation through raf-1 and extracellularly regulated protein kinases (Erks). We examined lung tumors 1-7 mm in largest dimension initiated in male Swiss mice by N-nitrosodimethylamine for pathologic type, Ki-ras mutations and levels of total Ki-ras p21, Ki-ras p21 bound to GTP, raf-1, Erk1 and Erk2 and their phosphorylated (activated) forms, and proliferating cell nuclear antigen. Total Ki-ras p21 and activated ras-GTP were not significantly greater in tumors than in normal lung or in tumors with versus those without Ki-ras mutations. Carcinomas with Ki-ras mutations were significantly smaller than those without mutations. Carcinomas were significantly larger than adenomas only for tumors without mutations. High levels of Erk2 and correlation of Erk2 amount with ras-GTP were specific characteristics of tumors with Ki-ras mutations. Size of all tumors correlated with ras-GTP but not with proliferating cell nuclear antigen. Raf-1 was expressed mainly in alveolar macrophages in normal lung but was focally upregulated in papillary areas of some tumors. The results indicate that Ki-ras influences the characteristics of lung tumors, but a linear ras-raf-Erk-cell-cycle control sequence does not adequately characterize tumorigenic events in this model. Mol. Carcinog. 28:156-167, 2000.     

Long-term effects of radiotherapy administered in childhood for the treatment of malignant diseases

Background: The use of radiotherapy for the treatment of childhood malignancy has improved long-term survival significantly, and many treated children now survive well into adulthood. As a consequence, long-term effects of childhood irradiation are being seen with increasing frequency. Methods: The medical records of 236 patients who had been treated for malignant disease with radiotherapy during childhood were examined to determine the long-term effect of the radiation on their growth and development. Results: Mean treatment dose was 35.5 Gy; mean age at treatment was 7.2 years; and mean follow-up was 14.5 years. Adjuvant chemotherapy was given to 82%. Some degree of bone deformity (usually with overlying soft-tissue hypoplasia) was seen in 40%; 21% developed some type of endocrine deficiency; 30% developed atrophic skin changes; and 7% developed second malignancies. The incidence of bone deformity and hormonal deficiency increased with the radiation dose; the incidence of second malignancy was independent of dose. Bone deformities were more common when radiation was administered before the age of 2 years. Conclusions: The consequences of radiotherapy in childhood are significant and must be considered when planning treatment. Even when treatment is essential, families should be informed of the possibility of growth disturbance to prevent subsequent misunderstanding.