Molecular basis of Lewis blood type in Taiwanese.

The Lewis (Le) histo-blood group system comprises two major antigens, Le(a) and Le(b) which are determined by alpha (1,2)-fucosyltransferase (FUT2) and alpha (1,3/1,4)-fucosyltransferase (FUT3). In this study, we analyzed the mutations of FUT2 and FUT3 genes in 101 Taiwanese by molecular biology method and compared them with their serologic phenotypes to explore their relationship. There is at least one wild allele of FUT2 and FUT3 genes in phenotype of Le (a-b+). The phenotypes of Le (a+b-) and Le (a+b+) are caused by mutations of both alleles of FUT2 gene and at least one wild allele of FUT3 gene. The genotypes of Le (a+b-) and Le (a+b+) are the same. Twenty cases are phenotype of Le (a-b-), which are caused by mutations of both alleles of FUT 2 gene and/or FUT 3 gene. Twelve cases were caused by both alleles mutations of FUT 3 gene only, while three cases were caused by mutations of both alleles of FUT2 gene and the rest of the cases were caused by mutations of both alleles of FUT2 and FUT3 genes. Our findings confirm that the Le histo-blood group is determined by the interaction of FUT 2 and FUT 3 genes. Our report is the first study of FUT 2 gene and FUT 3 gene in a Taiwanese population. We suggest that the genetic analysis of Le blood group should include FUT 2 and FUT 3 genes together.

The influence of exogenous nerve growth factor on inferior alveolar nerve regeneration in silicone tubes.

OBJECTIVE: To explore the effects of exogenous nerve growth factor (NGF) in the regeneration of adult white rabbit inferior alveolar nerves within silicone tubes. METHODS: Twenty-four adult white rabbits were selected. Bilateral 8 mm inferior alveolar nerve gaps were created, and the proximal and distal stumps were inserted into a 12 mm silicone tube. The right side silicone tube was filled with exogenous NGF (experimental group) and the contralateral side was filled with saline (control group). Regeneration of the nerves was assessed by histological and nerve eletrophysiological observation. Total number of the regenerated myelinated fibers, conduction velocity of the nerves, thickness of myelin sheaths, and cross-section area of myelinated nerve fibers between the experimental and control groups were compared. RESULTS: The results show that NGF significantly increased the number of myelinated fibers. The experimental group demonstrated more myelinated fibers than the controls at 12 and 18 weeks. At the same time following surgery, the myelin sheath thickness and the cross-section area of myelinated fibers in the experimental group were significantly greater than those in the controls. At 12 and 18 weeks, the conduction velocity of regenerated nerves in the experimental group were greater than those of the control. CONCLUSION: This study suggests that exogenous NGF can enhance regeneration of the inferior alveolar nerves and recovery of their sensory function.

[Investigation and analysis of pregnancy gingivitis in 700 pregnancy women]

OBJECTIVE: To investigate the relation between the incidence of pregnancy gingivitis and pregnancy period as well as oral hygiene of pregnancy women. METHODS: From January 1995 to April 1996,700 pregnancy women were inquired and examinated clinically. RESULTS: The incidence of pregnancy gingivitis is 73.57%,of which,the incidence during the first trimester is 67.49%,the second 74.19% and the third,79.17%.The incidence of pregnancy epulis is 0.43%. CONCLUSION: The incidence of pregnancy gingivitis was increasing following the pregnancy month and sexual hormone.It was important of pregnancy women to consulting about oral hygiene.

[The clinical observation of tetracycline stained teeth covered by composite resin veneer induced of secondary gingivitis]

Using gingival index,sulcus bleeding index and plaque index of 765 tetracycline stained teeth covered by composite resin veneer after 1/2-3 years were observed.It was found that the incidence of gingivitis was over 60%.The reexamination after three months later showed that the three indexes were significantly improved by grinding teeth proper and teaching standard brushing method.

[The clinical observation of 247 tuberculosis cases in Oral Maxillofacial region]

This paper presents a report of clinical observation on tuberculosis of oral and maxillofacial region in 247 patients.Of these which diagnosed by histopathology.94 cases are from mucous membrane of oral cavity,108 subjects from lymph nodes,27 ones from parotid gland,15 persons from facial dermis and 3 from jaw.Among 247 patients.154 cases were male and 93 female.The youngest was 2 years old and the eldest one was 71 of age and the mean age was 32 years old.The shortest course of disease was 15 days and the longest was 30 years,the mean course of time was two and half years.The rate of clinical diagnosis accord with pathology was 41.3%,most error diagnosis were to suspect inflammation,tumors and ulcer.In addition,the etiology,the clinical manifestion,diagnosis and therapies of oral and maxillofacial tuberculosis were analyzed.

[1585 cases of retinal detachment surgery with homologous skin as buckling material]. / Verwendung von homologer Kutis als Plombenmaterial in 1585 Fällen von Ablatiooperation.

From January 1963 to December 1989, 1585 consecutive cases of retinal detachment were operated with homologous skin as buckling material, the rate of operative success being 91.6%. Human skin is easy to obtain, sterilize and preserve; because of its appropriate thickness and firm but elastic consistency it satisfactorily meets the need to produce sufficient height and to maintain necessary duration of the scleral buckling; in addition to a high rate of reattachment, homologous skin implantation was well tolerated, very rarely rejected (0.06%) and infected (0.25%), and no late complications occurred. Therefore, the authors prefer using human skin as buckling agent rather than conventional synthetic material, e.g., silicon sponge etc.

A consecutive ultrastructural study of action of homoharringtonine on fibroblasts in vitro.

The authors studied the effect of homoharringtonine (Hh), a semisynthetic Chinese herb, on the ultrastructure of in vitro cultured human conjunctival fibroblasts (HFb) and its mechanism of action. Preliminary results showed that the main characteristics of HFb damage caused by Hh were invagination of the nuclear membrane, aggregation and margination of chromatin, and massive vacuolization of the cytoplasm. In addition, Hh can inhibit the secretion of collagen fibers and the synthesis of microfilaments. Therefore, Hh might be an effective agent in the prevention and treatment of proliferative eye disorders.

Periodontal conditions in elderly people of Shanghai, People's Republic of China, in 1986.

In a stratified multi-stage random sample, 1600 persons of 60 years and older in Shanghai, People's Republic of China, were investigated for periodontal conditions using the CPITN method. Periodontal conditions seemed to deteriorate steadily but rather slowly with increasing age. In the older age groups, there was a trend for an increased proportion of both subjects and sextants scoring CPITN code 4 (deep pockets). The increase in tooth loss with increasing age was more clearly visible: increasing percentages of edentulousness and decreasing mean numbers of teeth remaining in dentate subjects.

Complementation of a pleiotropic Nif-Gln regulatory mutant of Rhodospirillum rubrum by a previously unrecognized Azotobacter vinelandii regulatory locus.

A spontaneous pleiotropic Nif- mutation in Rhodospirillum rubrum has been partially characterized biochemically and by complementation analysis with recombinant plasmids carrying Azotobacter vinelandii DNA in the vicinity of ORF12 [Jacobson et al. (1989) J. Bacteriol 171: 1017-1027]. In addition to being unable to grow on N2 as a nitrogen source the phenotypic characterization of this and other metronidazole enriched spontaneous mutants showed (a) no nitrogenase activity, (b) the absence of NifHDK polypeptides, (c) a slower growth rate on NH4+, (d) approximately 50% higher glutamine synthetase (GS) activity than the wild-type, which was repressible, (e) an inability to switch-off GS activity in response to an NH4+ up-shift, and (f) an inability to modify (32P-label) the GS polypeptide. The apparent relationship between the absence of nifHDK expression and the absence of GS adenylylation cannot be explained in terms of the current model for nif gene regulation. However, R. rubrum transconjugants receiving A. vinelandii DNA which originated immediately upstream from nifH, restored all aspects of the wild-type phenotype. These data suggest a here-to-fore unrecognized relationship between nif expression and GS switch-off (adenylylation) activity, and the existence of a previously unidentified regulatory locus in Azotobacter that complements this mutation.

Scanning tunnelling microscopic images of amino acids.

We present images of amino acids adsorbed on highly orientated pyrolytic graphite (HOPG) obtained with the scanning tunnelling microscope (STM) in air. Individual molecules can be observed although the majority of adsorbates appear to form clusters. In the case of leucine, methionine, and tryptophan, two molecules often associate together to form a dimer. Single or dimer glycine molecules were not seen, but a cluster of a number of them was observed. The various adsorbed states may be related to the different interactions between the amino acids and the graphite surface. The mechanism of image formation of the amino acids is probably related to charge transfer mechanisms.

Ammonia switch-off of nitrogenase from Rhodobacter sphaeroides and Methylosinus trichosporium: no evidence for Fe protein modification.

In vivo switch-off of nitrogenase activity by NH4+ is a reversible process in Rhodobacter sphaeroides and Methylosinus trichosporium OB3b. The same pattern of switch-off in Rhodospirillum rubrum is explained by ADP-ribosylation of one of the Fe protein subunits, however, no evidence of covalent modification could be found in the subunits from either R. sphaeroides or M. trichosporium. Fe protein subunits from these organisms showed no variant behaviour on SDS-PAGE, nor were they 32P-labeled following switch-off. These observations suggest either that the attachment of the modifying group to the Fe protein in these organisms is quite labile and does not survive in vitro manipulation, or that the mechanism of switch-off is different than that seen in Rhodospirillum.

Inhibition of intraocular proliferation by homoharringtonine. An experimental study.

Homoharringtonine, an alkaloid indigenous to China, was studied for its effect on fibroblast growth in cell culture and on intraocular proliferation produced in rabbits by injecting homologous fibroblasts into the vitreous. The results demonstrate that homoharringtonine reduced the cell growth by 50% at a concentration of 0.005 mg/l in vitro, significantly inhibited vitreous proliferation, and prevented the occurrence of retinal detachment in vivo. Light and electron microscopy revealed no ocular toxicity in drug-treated eyes. Homoharringtonine may be of considerable value in the prevention and treatment of intraocular proliferation in patients.

Changes in amino acid and nucleotide pools of Rhodospirillum rubrum during switch-off of nitrogenase activity initiated by NH4+ or darkness.

Amino acid and nucleotide pools were measured in nitrogenase-containing Rhodospirillum rubrum cultures during NH4+- or dark-induced inactivation (switch-off) of the Fe protein. A big increase in the glutamine pool size preceded NH4+ switch-off of nitrogenase activity, but the glutamine pool remained unchanged during dark switch-off. Furthermore, methionine sulfoximine had no effect on the rate of dark switch-off, suggesting that glutamine plays no role in this process. In the absence of NH4+ azaserine, an inhibitor of glutamate synthate, raised glutamine pool levels sufficiently to initiate switch-off in vivo. While added NH4+ substantially increased the size of the nucleotide pools in N-limited cells, the kinetics of nucleotide synthesis were all similar and followed (rather than preceded) Fe protein inactivation. Darkness had little effect on nucleotide pool sizes. Glutamate pool sizes were also found to be important in NH4+ switch-off because of the role of this molecule as a glutamine precursor. Much of the diversity reported in the observations on NH4+ switch-off appears to be due to variations in glutamate pool sizes prior to the NH4+ shock. The nitrogen nutritional background is an important factor in determining whether darkness initiates nitrogenase switch-off; however, no link has yet been established between this and NH4+ (glutamine) switch-off.