[Rational close planting in raising the seedlings of Panax quinguefolium linn]

It has been found that the effect of planting density is hardly noticeable for one-year-old seedlings, but very apparent for 2-year-old ones. With the increase of planting density, the leaf area gets smaller, stem higher, and root thinner and shorter. The larger the planting density. The smaller the dry weights of canopy and root and the root-canopy ratio. It is thus advocated that rational planting densities be selected according to the proper cultivation systems.

[Reversed-phase HPLC determination of dracorhodin in Daemonorops draco]

A reversed-phase HPLC method for the determination of dracohobin in dragon's Blood is described. The separation was performed on a Nucleosil C18 7 microns (4.0 x 15 cm) column with a mobile phase of acetonitrile-methanol-0.05 mol/L NaH2PO4(30:5:65). Detection was at 270 nm.

[Investigation on the source of burn wound infection due to Staphylococcus aureus in children]

115 children with burn injuries were admitted between April 1988 and February 1989. Samples were taken from burn wounds, anterior nares and hands of every patient: anterior nares and hands of family members within 24 hours after admission. Samples were also taken from anterior nares and hands of medical personnel, air of ward and taps etc. 276 strains of S. aureus were isolated from 1544 samples. The rate of burn wound infection due to S. aureus was 25.2% and nasal carrier rates of patients, family members, nurses, doctors were 30.4%, 18.1%, 27.3% and 18.3%, respectively. S. aureus with the same plasmid profiles (1.6 and 1.9 Md) and phage type (618) as those of the burn wounds was only isolated from the anterior nares and hands of the family members and not from the medical personnel. It indicated that the S. aureus of burn wound infection mainly came from the hands of their family members and not from the medical personnel. This may be due to that care of burn wound was mainly taken by the family members.

[Role of rostral ventrolateral medulla in the "renzhong" induced pressor response in rabbits]

Experiments were performed on 14 rabbits locally anesthetized with procaine. Both vagus nerves were cut. The animals were immobilized with gallamine trithiodide and maintained by artificial ventilation. The effects of electrical stimulation of "Renzhong" area on arterial blood pressure and heart rate were observed before and after microinjection of kainic acid (KA) into rostral ventrolateral medulla (RVL). Electrical stimulation of "Renzhong" area could elicit a very marked increase in arterial blood pressure, before microinjection of KA into RVL. Bilateral microinjection of KA (0.5 microgram, an excitotoxin) into RVL could essentially abolish the pressor effect of stimulation of "Renzhong" area. However, bilateral microinjection of NS into RVL showed no effects on the pressor effect of stimulation of "Renzhong" area. These results suggest that RVL plays a key role in the pressor effect of "Renzhong" area stimulation.

Midazolam as a main anesthesia induction agent--a comparison with thiopental and diazepam

A clinical randomized investigation was undertaken to determine the value of midazolam as a narcotic adjuvant for anesthetic induction. Thirty ASA I-II adult patients undergoing selective surgery were allocated randomly into two groups to receive one of the following agents: midazolam 0.3 mg/kg, thiopental 5 mg/kg, or diazepam 0.4 mg/kg. The induction time as measured from the onset of injection to loss of the eyelash reflex was shortest in the case of thiopental; while a lower frequency of apnea, lesser suppression of circulation, and lack of venous irritation were points favoring midazolam. However, further study is needed to clarify the moderate cardiovascular response seen during intubation in some cases as well as to elucidate any patient population differences.

Dupuytren's disease among the Chinese in Taiwan

A retrospective study was made of 41 cases of Dupuytren's disease observed from 1970 to 1988 at the Veterans General Hospital-Taipei, Taiwan. The patients' ages ranged from 49 to 78 years; 21 patients had only one hand involved; 20 patients showed bilateral involvement. Thirty-three of 35 diseased hands with contracture were treated by regional fasciectomy. A follow-up study was done in 32 hands. The operative results of 30 hands were rated as good (94%); 3 showed extension of the disease and 1 had evidence of recurrence. Treatment was not given to 26 hands without contracture; 14 of these showed no change in the lesions, 3 improved, and 6 were worse when seen on subsequent visits. Seventeen of 33 excised thickened palmar fasciae contained nodules. All histological sections of nodule-free specimens showed dense connective tissues. Based on the fibroblastic activity and the amount of collagen, three easily discernible features of the histological make-up of the nodules were found.

Opening rate of acetylcholine receptor channels

The nicotinic acetylcholine (ACh) receptor is responsible for rapid conversion of chemical signals to electrical signals at the neuromuscular junction. Because the receptor and its ion channel are components of a single transmembrane protein, the time between ACh binding and channel opening can be minimized. To determine just how quickly the channel opens, we made rapid (100-400 microseconds) applications of 0.1-10 mM ACh to outside-out, multichannel membrane patches from BC3H-1 cells, while measuring the onset of current flow through the channels at 11 degrees C. Onset time is steeply dependent upon ACh concentration when channel activation is limited by binding of ACh (0.1-1 mM). At +50 mV, the 20-80% onset time reaches a plateau near 110 microseconds above 5 mM ACh as channel opening becomes rate limiting. Thus, we calculate the opening rate, beta = 12/ms, without reference to specific channel activation schemes. At -50 mV, the combination of a rapid, voltage-dependent block of channels by ACh with a finite solution exchange time distorts onset. To determine opening rate at -50 mV, we determine the kinetic parameters of block from "steady-state" current and noise analyses, assume a sequential model of channel activation/block, and numerically simulate current responses to rapid perfusion of ACh. Using this approach, we find beta = 15/ms. In contrast to the channel closing rate, the opening rate is relatively insensitive to voltage.

Temporal profile of the effects of pretreatment with brief cerebral ischemia on the neuronal damage following secondary ischemic insult in the gerbil: cumulative damage and protective effects

We examined the response of the gerbil brain to secondary ischemic insult following pretreatment with brief ischemia at intervals of 5 min, 1 and 6 h, 1, 2, 4, 7 and 14 days. Two minutes of bilateral carotid artery occlusion produced no histopathological brain damage, whereas 3 min of occlusion caused a moderate to severe reduction in the number of hippocampal CA1 pyramidal cells. Two-minute occlusion followed by 3-min occlusion at 5-min, 1- and 6-h intervals resulted in almost complete destruction of CA1 neurons. Additional neuronal damage was observed in the striatum at a 1-h interval and in the thalamus and the neocortex at 1- and 6-h intervals. The neuronal damage was most severe at a 1-h interval. Two-minute ischemia followed by 3-min ischemia at intervals of 1, 2, 4 and 7 days, however, caused a marked protective effect, and the hippocampal CA1 neurons were preserved. The protective effect was not observed at a 14-day interval and following pretreatment with 1-min ischemia. Thus, pretreatment with brief ischemia leads to complex responses of the brain to secondary ischemic insult; cumulative damage at intervals of 1-6 h and protective effects at intervals of 1-7 days.

[Localization of hepatocellular carcinoma with monoclonal antibodies]

We prepared monoclonal antibodies (MAbs) against hepatocellular carcinoma using cell suspensions isolated from surgical fresh hepatoma specimens as antigen. Totally we got 6 strains of hybridoma cell lines stably secreting MAbs for more than 2 years. Immunocytochemically they stained positively most of the paraffin embedded hepatoma tissues (63.1 to 91.1%) without reaction to the normal liver tissues. Localization of human hepatoma with 125I or 131I labelled MAbs in nude mice was done by IV injection, which showed clear tumor image by ECT radioimmunodetection and autoradiography of tissues. The T/N ratios of different MAbs were 3.1, 3.6, 5.15 and that of HAb 18-F (ab')2 was 14.4. Among 15 patients suspected to have hepatoma and given the labelled MAb, 13 proved pathologically to be hepatocellular carcinoma.

[Protein kinases and phospholipids in human hepatocellular carcinoma]

The activities of protein kinases C (PK-C), protein kinase A (PK-A) and other protein kinases independent of Ca(++)-phospholipid and cAMP in normal human liver and human hepatocellular carcinoma (HCC) xenograft in nude mice were determined. It was found that all the three protein kinases (PK-C, PK-A and the total "other" kinases) increased in HCC as compared with those in the normal liver. The increase was especially marked in PK-C. Its activity in cytosol was increased to 8.5 and 5.9 times as the normal values. It was also revealed that the relative content of phospholipids in the total lipid decreased in HCC. Among the constituent fractions of phospholipid, only lysophosphatidylcholine (LPC) was significantly increased both in absolute amount and its percentage in relation to total phospholipids. The causal relation between the increased PK-C activity and LPC is discussed.

Development of low- and high-serum culture conditions for use of human oral fibroblasts in toxicity testing of dental materials

With the aim of establishing conditions applicable to the testing of dental materials in human target cells, fibroblastic cell lines have been derived and grown from explants of human oral mucosa. Both a high-serum medium (termed "HSM") (CMRL 1066 supplemented with 10% fetal bovine serum) and a low-serum medium (termed "LSM") (a 1:1 mixture of M 199:MCDB 153 supplemented with 1.25% serum) supported radial outgrowths of cells from oral explants, as well as the subsequent transfer and growth of the cells in mass culture and at clonal density. Cells were typically fibroblastic in that they expressed vimentin uniformly, but did not express immunocytochemical markers of epithelial or endothelial cells. Cells derived in either LSM or HSM showed significantly higher colony-forming efficiency and clonal growth rate when transferred in LSM, as compared with HSM. Because cell migration occurred to a lesser extent in LSM, microscopic scoring of colony formation was also markedly facilitated. In both LSM and HSM, cellular low-molecular-weight thiols constituted about 30% of the total amount of sulfhydryls. Glutathione was present in about six- to seven-fold-higher amounts than cysteine--glutathione primarily in its reduced form and cysteine primarily in its oxidized form. A corrosion product of dental amalgam, i.e., Hg2+, decreased cell survival measured as colony-forming efficiency in a dose-dependent manner following either an acute (one h) exposure or continuous exposure (seven days). These studies demonstrated that human oral fibroblasts could be cultured at about one-tenth of the serum content that is commonly used.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of protein kinase C isozymes in rat optic nerves

Light (LM) and electron (EM) microscopic immunocytochemical methods were used to study the distribution of protein kinase C (PKC) isozymes in adult rat optic nerves. In cryostat and vibratome sections examined by LM, type II (beta) isozyme was localized almost exclusively in the axons. In the EM, immunoreaction products were found to associate with microtubules and neurofilaments. The inner surface of axonal membranes were occasionally stained. Analysis of PKC isozyme composition of the optic nerves by using immunoblot techniques revealed that type II (beta) isozyme accounted for approximately 80% of the total immunoreactivity. By contrast, type III (alpha) isozyme, which accounted for the remaining 20% of PKC, was found mainly in the astrocytes. Astrocytic processes next to blood vessels and between myelinated axons were stained. In the EM, immunoreaction products were found in the cytoplasm and along astroglial filaments. Segments of plasma membranes also were stained; but nuclei were unstained. Adult glial cells were not stained by an antibody to type II (beta) isozyme except for the occurrence of a few punctate cytoplasmic densities in occasional astrocytes. Very faint or no immunostaining was observed in sections treated with a monoclonal antibody to type I (gamma) isozyme. Immunoblot analyses also did not reveal this subspecies. The absence of type I (gamma) isozyme in optic nerves is not due to a down-regulation of the enzyme during development. In developing (5 and 11 day) rats, immunoreactivity of protein kinase C was very faint or absent. After 15 days, reaction products of both type III (alpha) and type II (beta) isozymes were found throughout the nerve. These findings suggest that type II (beta) isozyme may be involved in axonal transport whereas type III (alpha) isozyme may play a role in some astrocyte functions in mature optic nerves.

Growth regulation of serum-free cultures of epithelial cells from normal human buccal mucosa

Human buccal epithelial cells have been reared from explants maintained in supplemented MCDB 153 medium. Primary epithelial outgrowths show typical structural features and uniformly express keratins; subunit analyses demonstrate expression of keratins 5, 6, 14, 16/17, and 19. The cells exhibit up to 6% colony forming efficiency and divide at about 0.8 population doublings per day on fibronectin/collagen-coated dishes at clonal density. Studies of markers of proliferation and differentiation in buccal epithelial cells indicate that epidermal growth factor, cholera toxin, retinoic acid, and pituitary extract each exhibit a distinctive ability to enhance growth and variably affect cell migration and cell surface area. Transforming growth factor beta-1 inhibits growth and increases surface area without affecting migration, involucrin expression, and cross-linked envelope formation. Moreover, exposure of cells to fetal bovine serum, the tumor promoting agent 12-O-tetradecanoylphorbol-13-acetate or an elevated Ca2+ concentration (from 0.1 to 1 mM) inhibits growth and induces squamous differentiation as indicated by inhibition of migration, increases in surface area, involucrin expression, or formation of cross-linked envelopes. The results show that epithelial cells can be reproducibly derived from explant cultures of human buccal mucosa specimens and the cells transferred under serum-free conditions. Buccal epithelial cells in culture undergo a pattern of growth and differentiation that mimics parakeratinization in vivo and variably respond to several agents shown to modulate growth of cells that originate from other types of epithelia.

Electron-deficient isoalloxazines: model systems for disulfide prodrug formation

Drugs which contain a thiol functionality may be enzymatically or nonenzymatically oxidized to reactive metabolites, some of which cause adverse reactions. The synthesis of disulfide prodrugs to obviate unwanted drug side effects requires the development of novel catalysis. Herein, we describe the synthesis, structure-activity relationship, and mechanism investigations of the oxidation of model thiophenols with isoalloxazine disulfide formation catalysts. m-Nitrothiophenol reacts with the electron-deficient 8-cyano-N-3-(mercaptoalkyl)-10-phenylisoalloxazines and non-electron-deficient N-3-(mercaptoalkyl)-10-methylisoalloxazines to produce m-nitrothiophenol disulfide. m-Nitrothiophenol reacts with electron-deficient 8-cyano-10-phenyl-3-isoalloxazinepentanoic acid or 10-methyl-3-isoalloxazinepentanoic acid to form m-nitrothiophenol disulfide at a reduced rate, or not at all, respectively. Of the substituted isoalloxazines studied, electron-deficient isoalloxazines containing an N-3-mercaptoalkyl side chain were most efficient at catalyzing m-nitrothiophenol disulfide formation. Non-electron-deficient isoalloxazines without an N-3-alkyl mercaptan side chain did not catalyze m-nitrothiophenol oxidation. Electron-deficient isoalloxazines without N-3-alkyl mercaptan side chains catalyzed m-nitrothiophenol oxidation at 1/20 the rate for isoalloxazine 5. From kinetic and product studies, the differences in catalytic activity of 1-10 were judged to be due to changes in the chemical properties of the isoalloxazines and the ability to stabilize intramolecular thiol attack on the C(4a)-N(5) bond of the isoalloxazine. Electron-deficient isoalloxazines may be useful catalysts for the syntheses of disulfide prodrugs.

Anesthesia for primary hyperparathyroidism

We review the anesthesia used on patients with primary hyperparathyroidism from 1980-1989. As the first choice, nearly two thirds of the operations were performed under cervical epidural block, and about 90% of these obtained satisfactory results. Injury of the spinal cord and nerve root could be avoided by accurate insertion of the epidural needle. Respiratory depression might also be minimized with an alert perioperative course of 5 ml 0.8-1.33% lidocaine as the initial dose followed by 6-8 ml for maintenance. For complicated cases, such as those who had undergone previous cervical operations or were suspected of having ectopic parathyroidomas, general anesthesia was carried out instead.

Location of 43 kD mosquito-larvicidal toxin gene of highly toxic Bacillus sphaericus 10

The direct evidence of the location of the mosquito-larvicidal gene of Bacillus sphaericus 10 (isolated from Jiangsu Province of China) on megaplasmid pFW1 was given by molecular cloning. The clone (pFL109) containing the 1.4 kb HindIII DNA fragment from pFW1 expressed the mosquito-larvicidal toxin protein (43 kD). The location of the gene coding for the 43 kD toxin protein within the XhoI B fragment on the restriction map of pFW1 was confirmed by Southern blotting using the 1.4 kb HindIII DNA fragment as a probe. The non-toxic strains of Bacillus sphaericus were revealed to be 43 kD toxin gene deletion mutants by Southern and Western analyses. The 1.4 kb HindIII fragment of pFL109 can be used as a probe for differentiating the non-toxic strains of Bacillus sphaericus from the toxic ones.

The Saccharomyces cerevisiae genes (CMP1 and CMP2) encoding calmodulin-binding proteins homologous to the catalytic subunit of mammalian protein phosphatase 2B

Saccharomyces cerevisiae genomic clones that encode calmodulin-binding proteins were isolated by screening a lambda gt11 expression library using 125I-labeled calmodulin as probe. Among the cloned yeast genes, we found two closely related genes (CMP1 and CMP2) that encode proteins homologous to the catalytic subunit of phosphoprotein phosphatase. The presumed CMP1 protein (62,999 Da) and CMP2 protein (68,496 Da) contain a 23 amino acid sequence very similar to those identified as calmodulin-binding sites in many calmodulin-regulated proteins. The yeast genes encode proteins especially homologous to the catalytic subunit of mammalian phosphoprotein phosphatase type 2B (calcineurin). The products of the CMP1 and CMP2 genes were identified by immunoblot analysis of cell extracts as proteins of 62,000 and 64,000 Da, respectively. Gene disruption experiments demonstrated that elimination of either or both of these genes had no effect on cell viability, indicating that these genes are not essential for normal cell growth.

Current status of synthetic epikeratoplasty

Many of the deficiencies with human tissue epikeratoplasty might be improved by the use of a suitable synthetic lenticule. Potential biomaterials for epikeratoplasty include collagen (types I, III, or IV), collagen-hydrogel copolymers, bioactive synthetics, and coated hydrogels. The biomaterial must be engineered to achieve strict specifications of optical clarity, support of epithelial migration and adhesion, permeability to solutes, and stability to corneal proteases. Attaching synthetic lenticules to the cornea without cutting Bowman's layer by adhesives, laser welding, or direct adhesion may also improve the efficacy of synthetic epikeratoplasty.