Assessment of cerebral pO2 by EPR oximetry in rodents: effects of anesthesia, ischemia, and breathing gas

This report describes experiments designed to assess and illustrate the effectiveness of a new method for the measurement of cerebral interstitial pO2 in conscious rodents. It is based on the use of low frequency electron paramagnetic resonance (EPR) spectroscopy with lithium phthalocyanine as the oxygen sensitive probe. Magnetic resonance imaging was used to document placement of the probe in the brain, and to assess potential cerebral changes associated with the placement. The technique provided accurate and reproducible measurements of localized pO2 in the brains of conscious rodents under a variety of physiological conditions and for time periods of at least 2 weeks. Using this approach we quantitated the depressing effects on cerebral pO2 of three representative anesthetics, isoflurane, ketamine/xylazine, and sodium pentobarbital. The effects of changing the content of oxygen in the breathing gas was investigated and found to change the cerebral pO2. In experiments with gerbils, crystals of lithium phthalocyanine were implanted in each side of the brain and using a one-dimensional magnetic field gradient, simultaneous measurement of pO2 values from normal and ischemic (ischemia induced by unilateral ligation of a carotid artery) hemispheres of the brain were obtained. These results demonstrate that EPR oximetry with lithium phthalocyanine is a versatile and useful method in the measurement of cerebral pO2 under various physiological and pathophysiological conditions.

A clinical and neuroelectrophysiological study of hyperkalemic periodic paralysis

A case of atypical hyperkalemic periodic paralysis is reported. The diagnosis was confirmed by hyperkalemic test, cold water test, and differentiation of attack period and rest period by the measurement of motor nerve conduction amplitude. Etio-pathology of this disease is discussed from the view of neuroelectrophysiology.

Isolation of the protein backbone of an arabinogalactan-protein from the styles of Nicotiana alata and characterization of a corresponding cDNA

Arabinogalactan-proteins (AGPs) from the styles of Nicotiana alata were isolated by ion exchange and gel filtration chromatography. After deglycosylation by anhydrous hydrogen fluoride, the protein backbones were fractionated by reversed-phase HPLC. One of the protein backbones, containing mainly hydroxyproline, alanine, and serine residues (53% of total residues), was digested with proteases, and the peptides were isolated and sequenced. This sequence information allowed the cloning of a 712-bp cDNA, AGPNa1. AGPNa1 encodes a 132-amino acid protein with three domains: an N-terminal secretion signal sequence, which is cleaved from the mature protein; a central sequence, which contains most of the hydroxyproline/proline residues; and a C-terminal hydrophobic region. AGPNa1 is expressed in many tissues of N. alata and related species. The arrangement of domains and amino acid composition of the AGP encoded by AGPNa1 are similar to that of an AGP from pear cell suspension culture filtrate, although the only sequence identity is at the N termini of the mature proteins.

[Surgical removal of macular epiretinal membrane]

Vitreous surgery was used to remove macular epiretinal membranes in 15 eyes of 15 cases of which 7 were idiopathic and 8 secondary. In the period of postoperative follow-up, the visual acuity improved in 14 eyes (93%), in which 57% improved 3 or more than 3 lines. The visual recovery is related to the time of operation chosen. No complication was noted, except development of a paracentral scotoma in 1 eye.

S-RNase gene of Nicotiana alata is expressed in developing pollen

In the solanaceous plant Nicotiana alata, self-incompatibility is controlled by a single, multiallelic locus (S locus) expressed in both pollen and pistil. Previously, we have shown cosegregation between alleles of the S locus and alleles of a gene that encodes a glycoprotein with ribonuclease activity (S-RNase). Furthermore, expression of the S-RNase gene is apparently confined to the pistil and is correlated with the onset of self-incompatibility. In this paper, we report that the S-RNase gene is also expressed at low levels in developing pollen. A transcript in developing pollen hybridized to a cDNA encoding the S2-RNase allele of the parent plant and did not hybridize to cDNAs encoding other S-RNase alleles. Two cDNAs for the S2-RNase were cloned from a library derived from anthers of a plant homozygous for the S2 allele and both corresponded to the coding sequence of the S2-RNase. The product of the S-RNase gene was detected by immunocytochemistry in the intine of mature, hydrated pollen grains. These results are interpreted in the light of current knowledge of the structure of the S locus.

Combinatorial control of touch receptor neuron expression in Caenorhabditis elegans

Six touch receptor neurons with distinctive morphological features sense gentle touch in Caenorhabditis elegans. Previous studies have identified three genes (lin-32, unc-86 and mec-3) that regulate touch cell development. However, since other cell types also require these genes, we suspected that other genes help restrict the expression of touch cell characteristics to the six neurons seen in the wild type. To identify such genes, we have examined mutants defective in genes required for the development of other C. elegans cells for changes in the pattern of touch cell-specific features. Mutations in seven genes either reduce (lin-14) or increase (lin-4, egl-44, egl-46, sem-4, ced-3 and ced-4) the number of touch receptor-like cells. The combinatorial action of these genes, all of which are required for the production of many cell types, restrict the number of cells expressing touch receptor characteristics in wild-type animals by acting as positive and negative regulators and by removing cells by programmed cell death.

Endolaser photocoagulation after vitrectomy on rabbit's eyes

Ophthalmoscopic and histopathologic studies of endolaser photocoagulation after vitrectomy were carried out on rabbit's eyes. The endoprobe was connected to the Coherent "Novus 2,000" argon laser system. Under appropriate application the grayish white retinal lesions produced by argon green and argon all wavelength endolaser photocoagulation were similar ophthalmoscopically at a treatment power of 80-100 mw and exposure duration of 0.2s. Histopathologically, the characteristic changes of the retinal lesions produced by argon all wave-length were more significant than that produced by argon green endolaser photocoagulation. Scattered retinal photocoagulation can be done when the opaque medium is cleared on the operating table.

S-locus products in Nicotiana alata pistils are subject to organ-specific post-transcriptional processing but not post-translational processing

The expression of genes encoding self-incompatibility ribonucleases (S-RNases) in Nicotiana alata were examined at both protein and RNA level for organ specificity. S-RNases recovered from stigmas and styles were indistinguishable by SDS-PAGE, chromatographic behaviour and RNase specific activity. The pistil S transcripts are heterogeneous in size, the stigma transcript being shorter and more heterogeneous than the transcripts in the style and ovary. RNase H analysis shows that this organ-specific difference is mainly in the length of the polyadenylate tail. By sequence analysis of cloned cDNAs we show that the transcript present in the stigma is derived from the same gene as the transcript in the style.

Human transcription factor USF stimulates transcription through the initiator elements of the HIV-1 and the Ad-ML promoters

Earlier in vitro studies identified USF as a cellular factor which activates the adenovirus major late (Ad-ML) promoter by binding to an E-box motif located at position -60 with respect to the cap site. Purified USF contains 44 and 43 kDa polypeptides, and the latter was found (by cDNA cloning) to be a helix-loop-helix protein. In this report, we demonstrate a 25-to 30-fold stimulation of transcription via an upstream binding site by ectopic expression of the 43 kDa form of USF (USF43) in transient transfection assays. More recent data have also revealed alternate interactions of USF43 at pyrimidine-rich (consensus YYAYTCYY) initiator (Inr) elements present in a variety of core promoters. In agreement with this observation, we show here that USF43 can recognize the initiator elements of the HIV-1 promoter, as well as those in the Ad-ML promoter, and that ectopic expression of USF43 can stimulate markedly the corresponding core promoters (TATA and initiator elements) when analyzed in transient co-transfection assays. Mutations in either Inr 1 or Inr 2 reduced the USF43-dependent transcription activity in vivo. In addition, in vitro transcription assays showed that mutations in either or both of the Inr 1 and Inr 2 sequences of the HIV-1 and Ad-ML promoters could affect transcription efficiency, but not the position of the transcriptional start site. These results indicate that USF43 can stimulate transcription through initiator elements in two viral promoters, although the exact mechanism and physiological significance of this effect remain unclear.

[Quality of dihuang (Rehmannia spp.)]

In this paper, the contents of catalpol, water-extract and alcohol-extract materials, ash, total reducing sugar and inorganic elements in Dihuang from different habitats have been measured. The result shows that Huai Dihuang, the genuine drug, excels all those from other habitats in quality. The quality of commercial dry Dihuang may be related closely to the production area, storage time, etc.

A clinical study on diabetic retinopathy

A clinical research on the diabetic retinopathy(DR) is reported. In the 662 cases of diabetes mellitus examined, the prevalence of DR was 51.3%, of which 7.6% were preproliferative and 7% proliferative. The study showed that when the disease progressed to the preproliferative and proliferative DR, laser photocoagulation could be the best treatment of choice, and panretinal photocoagulation was also quite effective in the treatment of pregnant patients with proliferative diabetic retinopathy.

Preparation of lipid emulsions by pressure extrusion

Lipid emulsions consisting of a surface monolayer of phospholipid enclosing a core of neutral lipids have been prepared by repeated extrusion through polycarbonate filters of defined pore size. Particle size, as measured by photon correlation spectroscopy, decreases on successive passes through a 100 nm filter, reaching a near constant value (130-150 nm) after 4 passes. A corresponding decrease in the standard deviation of the particle size distribution occurs during this process. The recovery of lipids, especially of cholesterol and cholesterol ester, is improved if the emulsion is sonicated before extrusion through filters. [31P]-NMR and fluorescence techniques are used to confirm that the resulting structures are emulsions rather than lipid bilayers.

[Prevention of radiation injury of the lungs by Salvia miltiorrhiza in mice]

The lungs and thymus of mice received X-ray irradiation on the right thorax were observed. It was found that lung injury was lighter and got recovered more rapidly in mice given Salvia miltiorrhiza than that in the control group. Microscopic thymus changes showed no difference in the two groups. The results indicated that Salvia miltiorrhiza could prevent radiation-induced pulmonary injury, but could not prevent thymus injury.

Identification of temperature-sensitive DNA- mutants of Chinese hamster cells affected in cellular and viral DNA synthesis

We described a strategy which facilitates the identification of cell mutants which are restricted in DNA synthesis in a temperature-dependent manner. A collection of over 200 cell mutants temperature-sensitive for growth was isolated in established Chinese hamster cell lines (CHO and V79) by a variety of selective and nonselective techniques. Approximately 10% of these mutants were identified as ts DNA- based on differential inhibition of macromolecular synthesis at the restrictive temperature (39 degrees C) as assessed by incorporation of [3H]thymidine and [35S]methionine. Nine such mutants, selected for further study, demonstrated rapid shutoff of DNA replication at 39 degrees C. Infections with two classes of DNA viruses extensively dependent on host-cell functions for their replication were used to distinguish defects in DNA synthesis itself from those predominantly affecting other aspects of DNA replication. All cell mutants supported human adenovirus type 2 (Ad2) and mouse polyomavirus DNA synthesis at the permissive temperature. Five of the nine mutants (JB3-B, JB3-O, JB7-K, JB8-D, and JB11-J) restricted polyomavirus DNA replication upon transfection with viral sequences at 33 degrees C and subsequent shift to 39 degrees C either before or after the onset of viral DNA synthesis. Only one of these mutants (JB3-B) also restricted Ad2 DNA synthesis after virion infection under comparable conditions. No mutant was both restrictive for Ad2 and permissive for polyomavirus DNA synthesis at 39 degrees C. The differential effect of these cell mutants on viral DNA synthesis is expected to assist subsequent definition of the biochemical defect responsible.