Global warming, plant paraquat resistance, and light signal transduction through nucleoside diphosphate kinase as a paradigm for increasing food supply.

Light signal transduction was studied in extracts of mycelia of the fungus Neurospora crassa, and the third internodes of dark-grown Pisum sativum cv Alaska. Both processes increased the phosphorylation of nucleoside diphosphate kinase (NDPK). NDPK may function as a carrier of reduction equivalents, as it binds NADH, thereby providing electrons to transform singlet oxygen to superoxide by catalases (CAT). As the C-termini of NDPK interact with CAT which receive singlet oxygen, emitted from photoreceptors post light perception (which is transmitted to ambient triplet oxygen), we hypothesize that this may increase phospho-NDPK. Singlet oxygen, emitted from the photoreceptor, also reacts with unsaturated fatty acids in membranes thereby forming malonedialdehyde, which in turn could release ions from, e.g., the thylacoid membrane thereby reducing the rate of photosynthesis. A mutant of Alaska pea, which exhibited two mutations in chloroplast NDPK-2 and one mutation in mitochondrial localized NDPK-3, was resistant to reactive oxygen species including singlet oxygen and showed an increase in the production of carotenoids, anthocyanine, and thereby could reduce the concentration of singlet oxygen. The reduction of the concentration of singlet oxygen is predicted to increase the yield of crop plants, such as Alaska pea, soybean, rice, wheat, barley, and sugarcane. This approach to increase the yield of crop plants may contribute not only to enhance food supply, but also to reduce the concentration of CO(2) in the atmosphere.

Idiopathic Retroperitoneal Hematoma.

A 34-year-old female presented with sudden onset of severe abdominal pain in a flank distribution. A large mass was palpable in the right upper quadrant on physical examination. Abdominal contrast-enhanced computed tomography showed a well-defined, right-sided, retroperitoneal cystic lesion located between the abdominal aorta and the inferior vena cava (IVC). The tumor size was 55 × 58 mm, and it compressed the gallbladder and the duodenum. Upper gastrointestinal radiography revealed a stricture of the second portion of the duodenum by the tumor. T2-weighted magnetic resonance imaging showed that the whole part was hyperintense with hypointense rims, but the inner was partially hypointense. Based on the radiological findings, the preoperative differential diagnosis included retroperitoneal teratoma, Schwannoma, abscess, and primary retroperitoneal tumor. On laparotomy, the tumor was located in the right retroperitoneal cavity. Kocher maneuver and medial visceral rotation, which consists of medial reflection of the upper part of right colon and duodenum by incising their lateral peritoneal attachments, were performed. Although a slight adhesion to the IVC was detected, the tumor was removed safely. Thin-section histopathology examination detected neither tumor tissues nor any tissues such as adrenal gland, ovarian tissue, or endometrial implants. The final pathological diagnosis was idiopathic retroperitoneal hematoma; the origin of the bleeding was unclear. The patient was discharged without any complication 5 days after the operation.

A tetraploid liveborn neonate: cytogenetic and autopsy findings.

Cytogenetic and autopsy findings of a nonmosaic tetraploid male neonate, alive until shortly after birth at 37 weeks' gestation, are described. Oligohydramnios, intrauterine growth retardation, cranial abnormalities, and Dandy-Walker malformation were noted prenatally. Autopsy findings included cleft lip and palate; overlapping fingers; low-set ears; simian creases; hypoplastic external genitalia with undescended testes; Dandy-Walker malformation; slightly dilated lateral and third ventricles; hypoplasia of the cerebrum, pons, medulla, pituitary gland, thymus, lung, adrenal gland, and kidney; large ventricular septal defect; and enteric cyst behind the urinary bladder. The placenta was hypoplastic and showed no remarkable abnormalities, except for mild syncytial knots. Chromosome analyses of amniotic fluid cells at 31 weeks' gestation and the umbilical cord blood cells at delivery revealed a 92,XXYY karyotype. G-, C-, Q-, and N-banding heteromorphic studies demonstrated duplication of paternal chromosomes 1, 3, and 15, and maternal chromosome 22. In addition, the results of an analysis with 16 CA repeat polymorphic markers were consistent with duplicated inheritance of 1 paternal and 1 maternal haploid sets to the tetraploid patient. Therefore, it is most likely that the tetraploidy was caused by a cytoplasmic cleavage failure at the first mitotic division.

Immunocytochemical study of activin type IB receptor (XALK4) in Xenopus oocytes.

Studies have shown that the activin type IB receptor is specific for activin/nodal signaling. Activin is produced by follicle cells in the ovary, and is incorporated into the oocytes. Antisera against three peptides were prepared, encompassing the extracellular, intracellular and serine/threonine kinase domains of the Xenopus type IB activin receptor (XALK4). Immunocytochemistry was done using these antisera to investigate the distribution of XALK4 in the Xenopus ovary. All three antisera stained the mitochondrial cloud of Xenopus previtellogenic oocytes. Purified antibody against the intracellular domain also recognized the mitochondrial cloud. Immunoelectron microscopy localized XALK4 on the endoplasmic reticulum of the mitochondrial cloud, although not on mitochondria.