Identification of a putative eukaryotic-like protein kinase family in the developmental bacterium Myxococcus xanthus

Myxococcus xanthus is a gram-negative bacterium which, upon starvation, undergoes a spectacular developmental cycle culminating in the formation of spore-filled fruiting bodies. We recently characterized a protein serine-threonine kinase (Pkn1) that is required for normal development (J. Munoz-Dorado, S. Inouye, and M. Inouye, Cell 67:995-1006, 1991). pkn1 was cloned by polymerase chain reaction amplification with primers designed from conserved sequences in eukaryotic protein kinases. In this study, a fragment of the pkn1 gene and an oligonucleotide corresponding to another highly conserved region were employed as probes for Southern blot analyses, which indicated that there are at least 26 putative kinase genes in M. xanthus. Most of the putative kinase genes were cloned, and complete or partial sequencing of eight clones revealed that they indeed contained highly conserved sequences present in eukaryotic kinases. These results suggest that complex kinase cascades similar to those described for eukaryotes might be involved in regulation of the M. xanthus life cycle.

Negative thyroid hormone control of human growth hormone gene expression is mediated by 3'-untranslated/3'-flanking DNA

The intact human growth hormone (hGH) gene is negatively regulated by triiodothyronine (T3) treatment in transfected rat pituitary tumor cells. We now demonstrate that this responsiveness is mediated by a negative thyroid hormone response element (nTRE) localized to the proximal 3'-untranslated/3'-flanking region (3'-UT/FR). This region binds thyroid hormone receptors specifically and with high affinity. nTRE function was promoter-dependent, since it suppressed the activity of a positive TRE in the human chorionic somatomammotropin promoter, partially repressed activity of the herpes simplex virus TK promoter, but did not function with the human actin or Rous sarcoma virus promoters. T3 treatment did not alter transcript termination sites nor selectively affect the stability of transcripts containing the hGH 3'-UT/FR when transcription was blocked by actinomycin D treatment. The function of the nTRE depended on its location in the 3'-UT/FR; it was inactive when positioned down-stream of the simian virus 40 (SV40) 3'-UT/FR, and it acted as a positive TRE when placed upstream of the hGH promoter. These results demonstrate a novel localization of a TRE with unique properties which suggests expanded mechanisms by which thyroid hormone receptors can affect gene expression.

Complete enzymatic deglycosylation of native sex steroid-binding protein (SBP or SHBG) of human and rabbit plasma: effect on the steroid-binding activity

An enzymatic procedure for the complete removal of the N-linked and O-linked oligosaccharide side chains of the sex steroid-binding proteins (SBP or SHBG) of human and rabbit plasma under native conditions is described. Deglycosylation was catalyzed by N-glycanase, neuraminidase, and O-glycanase and was monitored by SDS-PAGE, lectin blotting, and molecular weight analyses by electrospray mass spectrometry. Digestion of rabbit SBP with N-glycanase generated a major 39,777-Da protein and two minor ones of 39,389 and 39,545 Da. The molecular weight of the major protein agrees with the molecular weight calculated from the sequence of the sugar-free polypeptide monomer (39,769 Da: Griffin, P.R., Kumar, S., Shabanowitz, J., Charbonneau, H., Namkung, P.C., Walsh, K.A., Hunt, D.F., & Petra, P.H., 1989, J. Biol. Chem. 264, 19066-19075), whereas the other two are deglycosylated proteolytic cleavage products lacking the TQR and TQ sequences at the amino-terminus. The N- and O-linked side chains of human SBP were removed by sequential digestion with N-glycanase and neuraminidase/O-glycanase. A 38,771-Da protein was generated, which agrees well with the molecular weight of the sugar-free polypeptide monomer (Walsh, K.A., Titani, K., Kumar, S., Hayes, R., & Petra, P.H., 1986, Biochemistry 25, 7584-7590). N-deglycosylation of human and rabbit SBP has no effect on the steroid-binding activity, but removal of the O-linked side chains of N-deglycosylated human SBP results in an apparent 50% loss of steroid-binding activity and an increase in the Kd for the binding of 5 alpha-dihydrotestosterone from 0.3 mM to 0.9 nM.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of myelinated and unmyelinated fibers of human vagus nerve during the first year of life

As an important component of cardiorespiratory control, the vagus nerve and its maturation were evaluated in normal infants in order to provide standards of comparison with infants with dysfunctional neural control mechanisms. Myelinated and unmyelinated fibers in the cervical vagus nerve were examined in 27 term infants. Number of fibers, axon diameters, and myelin thickness were compared among four age groups. The histograms of axon size exhibited a skewed distribution that persisted during the age range examined for both myelinated and unmyelinated vagus fibers. Fiber size distributions of myelinated fibers, however, already showed an incipient multimodal distribution after 3 months. No major increase was observed in the average axon size of myelinated and unmyelinated fibers. A significant increase was observed, however, in the average content of myelin in myelinated fibers expressed as myelin thickness, number of lamellae or g ratio (internal/external diameter). These results suggest an active myelination during the first 9 months of life without a major change in the axonal characteristics of the fibers. A marginal increase in the density of myelinated fibers with age, both in terms of total number and the relation to unmyelinated fibers, suggests a slow transition from unmyelinated to myelinated fibers during the first year of life, particularly during the first 3 months. The present morphometric parameters indicate an active deposition of myelin before the maturation of cross-axonal dimensions. The distribution of g ratios also suggests that optimal conduction velocity is compromised only in a fraction of all vagal myelinated fibers.

High dose mitomycin C for treatment of advanced gastric cancer

Thirty five patients (26 males and 9 females) with advanced gastric cancer confirmed by pathology were treated by high-dose mitomycin C. According to the following dose and schedules: Mitomycin C 20 mg intravenously per week and a total of 60 mg. Three weeks later, all the patients received FT-207 600 mg daily and a total of 20-40 g. The ages ranged from 24 to 75 years, 11 had cancer of cardia, 6 had cancer of gastric body, and 18 had cancer of gastric antrum. Eleven patients could not have an operation. Seventeen patients were recurrence of post operation. Eighteen of 35 patients received CR (7/35) and PR (11/35), the response rate was 51.43% of the responders, the median duration of remission and survival were 7.3 (range, 2-16) and 12.2 (range, 3-30) months, respectively. Common doses were instilled. The main side effects were leukopenia (10/35) and thrombocytopenia (7/35). None of these patients had liver and kidney function damage.

Nucleic acid related compounds. 74. Synthesis and biological activity of 2'(and 3')-deoxy-2'(and 3')-methylenenucleoside analogues that function as mechanism-based inhibitors of S-adenosyl-L-homocysteine hydrolase and/or ribonucleotide reductase

Treatment of 2-amino-6-chloro-9-(beta-D-ribofuranosyl)purine (21) with TBDMS chloride/imidazole/DMF gave a separable mixture of 5'-O, 2',5'-bis-O (22), 3',5'-bis-O (23), and 2',3',5'-tris-O-TBDMS derivatives. Oxidation of 22 and 23 with CrO3/pyridine/Ac2O, treatment of the respective ketonucleosides with methylenetriphenylphosphorane, and deprotection gave 2-amino-6-chloro-9-[3(and 2)-deoxy-3(and 2)-methylene- beta-D-erythro-pentofuranosyl]purines (28 and 37) that were converted into other 2-amino-6-substituted-purine analogues. Tubercidin was converted into 2'-deoxy-2'-methylenetubercidin (49) by an analogous route. Inactivation of S-adenosyl-L-homocysteine hydrolase by 2'- and 3'-methyleneadenosine analogues was investigated. Mechanism-based inhibition of S-adenosyl-L-homocysteine hydrolase and anticancer and antiviral activities of 2'(and 3')-deoxy-2'(and 3')-methylenenucleoside analogues are discussed.

Measurement of brain perfusion by volume-localized NMR spectroscopy using inversion of arterial water spins: accounting for transit time and cross-relaxation

The theoretical model for perfusion measurement by NMR using arterial labeling of endogenous water is extended to include the effects of transit time and cross-relaxation of tissue water with macromolecules. Water magnetization in rat brain is monitored using the STEAM method to simultaneously determine the transit time, magnetization transfer rate constant, and perfusion. The results show that the transit time in rat brain is quite short, and thus its effect on perfusion measurement is small. It is also demonstrated both theoretically and experimentally that the steady-state effects of cross-relaxation with macromolecules on perfusion measurement are accounted for by a proper control experiment.

Stress distribution and bone density in the lumbar spine

The stress distribution of the lumbar spine was analyzed with a mechanical model of the lumbar motion segment constructed by a three-dimensional finite element method, and the results were compared with the corresponding bone density represented by the value of CT. The results showed that the stress levels in the various parts of the lumbar spine were closely related to the CT values. The authors conclude that the dynamic balance of bone growth is maintained in large part by mechanical stress.

Halothane gene and swine performance

One hundred thirty-one pigs representing seven different breed groups (Minnesota No. 1 [M], Pietrain [P], Yorkshire [Y], and crosses PY, P[PY], P[NP], and P[YP]P) and three halothane gene genotypes (NN, Nn, and nn) were tested for breed, sex, and halothane gene (HAL) effects on growth and carcass performance. Breed effects were significant for all traits measured. Sex effect was significant for most traits except for meat scores. The HAL-locus linkage group explained 20 to 30% of the total variation for meat quality scores and 1 to 10% for meat quantity and growth traits. Pietrain x Yorkshire was the fastest growing breed group and had relatively good carcass quality. Pietrain and its related crosses had the most lean muscle but the lowest meat quality. The HN (HAL negative, genotype Nn) individuals within the PPY and PNP groups grew more quickly and had higher meat quality scores and less muscling than HP (HAL positive, genotype nn) individuals. A second experiment with 40 pigs showed significant differences in fat concentration in the loin muscle between breeds (M, Y, and P) and between genotypes within the NP population (NP[HP] and NP[HN]). The phenotypic correlation between fat percentage and marbling was .59 (P less than .01). The NP(HP) had higher water percentage in lean than the NP(HN). The water percentage was negatively correlated with meat quality scores of color, firmness, and marbling with phenotypic correlations of -.10, -.23, and -.57 (P less than .01), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

N x N to N pattern associative memory by using optoelectronic neurochips

A scheme of N x N to N pattern associations based on a fully connected neural network is proposed. The connection weight matrix of the neural network with N neurons is defined by the input pattern of size N x N through a linear transformation. The point attractor of the system state for this input pattern is then used as the associative output to identify the input pattern. This scheme can be implemented by the optoelectronic neurochips in a simple fashion. The learning algorithm, the simulation results, and the implementation are presented.

The phosphorylation of retinoblastoma gene product in human myeloid leukemia cells during the cell cycle

Counterflow centrifugal elutriation and immunoblotting techniques were used to study the expression of the retinoblastoma (RB) gene during the cell cycle of BV173 chronic myeloid leukemia (CML) cells. Our data showed that Rb protein started to be phosphorylated at early G1 phase, became hyperphosphorylated when cells progressed to late G1 and S phases during cell cycle, and remained hyperphosphorylated throughout S and G2/M phases. Our data suggest that Rb phosphorylation starts at a more distal point to the G1/S phase boundary in human myeloid leukemia BV173 cells rather than at a point more proximal to the G1/S boundary, as seen in HeLa cells.

In vivo muscle 31P nuclear magnetic resonance spectroscopy during treatment of halothane-sensitive and halothane-nonsensitive pigs

In vivo muscle 31P nuclear magnetic resonance spectroscopy was performed on 10 female pigs originating from a homozygous halothane-sensitive line and on 10 female pigs from a homozygous halothane-nonsensitive line. The mean concentration of phosphocreatine in the biceps femoris muscle of the anesthetized pigs decreased to 86% of the initial value after 11 minutes of halothane exposure (3%, oxygen flow 3 L/min). After the next 5.6 minutes, phosphocreatine concentration reached a minimal value of 52%, followed by a mean recovery to 76% of the initial value during the ensuing 11 minutes. Response was not observed in anesthetized homozygous halothane-nonsensitive pigs. Thus, a decrease to 86% of the initial value of phosphocreatine was 100% predictive for homozygous halothane-sensitive pigs with body weight ranging from 10 to 18 kg.

Computer simulation of marker-assisted selection utilizing linkage disequilibrium

The value of marker-assisted selection (MAS) using linkage disequilibrium between genetic markers and quantitative trait loci (QTL) was examined. To simulate the disequilibrium, four base populations were created, F2, F5, F10 and F20, by random mating from a cross between two inbred lines. Selections were on breeding values estimated from: (1) marker QTL (MQTL) associations (MAS); (2) conventional best linear unbiased prediction (BLUP) methods; and (3) a combination of 1 and 2 (COMB). Alternative cases were studied by varying the parameters (heritability, initial linkage disequilibrium, and distribution of QTL effects). A genome with 100 QTL and 100 markers randomly (but equally) spread over 20 chromosomes, each 100 centiMorgans (cM) in length, was generated. Linkage disequilibrium (over 30 replicates) of QTLs with their nearest marker averaged 0.153, 0.104, 0.068, and 0.047 for the four base populations, and fell to 0.035, 0.025, 0.021, and 0.018, respectively, after ten generations of MAS selection (heritability 0.25). The initial linkage disequilibrium had the greatest effect on the genetic gain by MAS with the responses for the base populations F2>F5>F10>F20. Genetic gains by conventional BLUP selection were usually greater than by MAS. However, MAS contributed to the combined selection (COMB) to give appreciably higher genetic responses. Hybridization of selected lines after several generations of selection contributed little to generating further linkage disequilibrium. Detection of markers closer to the QTL will increase the linkage disequilibrium available for selection. Eventually with very close linkage each QTL allele can be uniquely identified in selection, and selection will then be equivalent to selection on the QTLs themselves.

Mammalian expression of the human sex steroid-binding protein of plasma (SBP or SHBG) and testis (ABP). Characterization of the recombinant protein

A full-length 1,209 bp cDNA encoding the human sex steroid-binding protein of plasma (SBP or SHBG) and testis (ABP) was constructed and expressed in BHK-21 cells. The sequence agrees with the published gene and protein sequences. The cells were found to secrete SBP following transfection and G418r selection. The recombinant protein binds 5 alpha-dihydrotestosterone with a Kd of 0.28 nM. It also binds testosterone and 17 beta-estradiol but not progesterone, estrone or cortisol revealing a steroid-binding specificity identical to that of human SBP. SDS-PAGE patterns are less complex than human SBP and show a monomeric molecular weight of about 43 kDa.

Proliferation of hematopoietic cells is accompanied by suppressed expression of heat shock protein 70

In this study, we have examined the synthesis of heat shock protein (HSP70) in leukemia cells from acute myelogenous leukemia (AML) patients and in mononuclear cells from normal individuals, before and after growth factor stimulation. We have shown that the HSP70 protein was expressed in these cells in the absence of temperature elevation. Stimulation of proliferation of AML cells by the growth factors interleukin-3 and granulocyte-macrophage colony-stimulating factor and stimulation of normal lymphocytes by phytohemagglutinin (PHA) resulted in decreased synthesis of HSP70, suggesting that high levels of HSP70 are associated with cellular differentiation.

Elimination of immune tolerance to hepatitis virus in an animal model

Four-day old ducklings were infected with duck hepatitis B virus to simulate perinatal transmission of hepatitis B virus. Immune tolerance was characterized as persistent viremia, antigenemia, without detection of anti-DHBs or anti-DHBc. A synthetic peptide, P125-146, mimicking one of the epitopes of the native DHBV Pre-S protein was used to cross-link to tetanus toxoid or phytohemagglutinin. These 'novel' antigens were used to immunize immune tolerant ducks, aimed at bypassing T cell tolerance. After 5 injections, though no anti-DHBV Pre-S was detected, around 50% of the immunized ducks showed seroconversion to DHBV DNA negative.

Modified CelliGen-packed bed bioreactors for hybridoma cell cultures

This study describes two packed bed bioreactor configurations which were used to culture a mouse-mouse hybridoma cell line (ATCC HB-57) which produces an IgG1 monoclonal antibody. The first configuration consists of a packed column which is continuously perfused by recirculating oxygenated media through the column. In the second configuration, the packed bed is contained within a stationary basket which is suspended in the vessel of a CelliGen bioreactor. In this configuration, recirculation of the oxygenated media is provided by the CelliGen Cell Lift impeller. Both configurations are packed with disk carriers made from a non-woven polyester fabric. During the steady-state phase of continuous operation, a cell density of 10(8) cells per cm3 of bed volume was obtained in both bioreactor configurations. The high levels of productivity (0.5 gram MAb per 1 of packed bed per day) obtained in these systems demonstrates that the culture conditions achieved in these packed bed bioreactors are excellent for the continuous propagation of hybridomas using media which contains low levels (1%) of serum as well as serum-free media. These packed bed bioreactors allow good control of pH, dissolved oxygen and temperature. The media flows evenly over the cells and produces very low shear forces. These systems are easy to set up and operate for prolonged periods of time. The potential for scale-up using Fibra-cel carriers is enhanced due to the low pressure drop and low mass transfer resistance, which creates high void fraction approaching 90% in the packed bed.

[Relationship between different patterns of left ventricular hypertrophy and plasma norepinephrine and hemorheology in patients with essential hypertension]

The changes of plasma norepinephrine (NE) concentration and hemorheology in 60 patients with essential hypertension (EH) with different patterns of left ventricular hypertrophy (LVH) were observed. The results showed that a higher value in whole blood viscosity (WBV) at a shear rate of 230-s was found in concentric hypertrophy (CH) group; a significant increase in plasma NE was found in asymmetric septal hypertrophy (ASH) group. It suggests that CH appear to be a compensation adapting to the increase in afterload. Significant increase in plasma NE concentration may play an important role in the development of ASH in addition to the afterload.

[Preparation of stable W/O/W type multiple emulsion containing water-soluble drugs and in vitro evaluation of its drug-releasing properties]

The stable water-in-oil-in-water (W/O/W) multiple emulsion was prepared by a two-step procedure for emulsification using glyceryl tricaprylate (Panasate-800) as the oil phase. The water-soluble drugs such as cefadroxil, cephradine, 4-aminoantipyrine, and antipyrine were selected and entrapped separately in the inner aqueous phase of W/O/W multiple emulsion. In consideration of parenteral administration, pH 7.4 phosphate buffered saline was used in both inner and outer aqueous phases. Moreover, these multiple emulsions could be significantly stable for a month at room temperature by the addition of hydrophilic polymer like gelatin and of amino acid like lysine to the inner aqueous phase.

Combined treatment with photodynamic therapy and chemotherapy for advanced cardiac cancers

In all, 144 patients with advanced cardiac cancers have been treated by photodynamic therapy (PDT), combined chemotherapy and chemotherapy alone from September 1982 to July 1990. A total of 5 mg kg-1 haematoporphyrin derivative (HpD) was intravenously given 48-72 h prior to PDT. The light source was an argon dye laser with an output beam of 630 nm. The irradiation time varied between 12 and 25 min with a fluence of 100-350 mW cm-2. The entire tumour was irradiated with a light dose of 100-250 J cm-2. The combination of UFT and mitomycin C was used as standard chemotherapy. There were 26 responders out of 55 patients (47.3%) in the group treated with PDT alone, 24 out of 41 (58.5%) in the PDT+chemotherapy group, and 24 out of 48 (50.0%) in the chemotherapy alone group. In the PDT+chemotherapy group 19.5% patients had complete remission, which was better than the other two groups (5.5%, 8.3%, p less than 0.05). The following survey of all patients lasted from six months to seven years. The results suggest that a combination of PDT and chemotherapy may prove effective.

Tumoricidal activity of Kupffer cells augmented by anticancer drugs

The effect of Mitomycin-C (MMC) and Adriamycin (ADM) on the antitumor-associated function of Kupffer cells was examined. MMC and ADM enhanced the production of superoxide by Kupffer cells in cultures at low concentrations likely to occur in clinical use. The expression of interleukin-2 receptor, Ia antigen and asialoGM1 antigen, measured by flowcytometry, was increased by contact with MMC. Growth inhibition of AH130, rat ascites hepatoma, and P815, murine mastocytoma, by Kupffer cells treated with anticancer drugs was greater than that by Kupffer cells alone or anticancer agent alone. These results show that MMC and ADM activate Kupffer cells, leading to synergistic antitumor activity. The results suggest that some anticancer agents act through immunological mechanisms as well as through direct antineoplastic activity.

Improvement of PCR sequencing by formamide

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Polarized distribution of coated pits and coated vesicles in the rat lens: an electron microscopy and WGA-HRP tracer study

The presence and distribution of coated pits (CPs) and coated vesicles (CVs) in the rat lens were studied by thin-section electron microscopy (TEM) and wheat germ agglutinin-horseradish peroxidase (WGA-HRP) as a tracer. TEM revealed that CPs and CVs were approximately 150 nm in diameter, of which the characteristic clathrin coat was approximately 20 nm thick. CPs and CVs were found in both epithelium and superficial fiber cells of the entire lens, and were distributed preferentially along the basal membrane facing the lens capsule. It was estimated that more than 80% of CPs and CVs in the entire epithelium were seen along the basal membrane. The number of CPs and CVs along the basal membrane in the equatorial epithelium (4.4 per 10 microns membrane) was similar to that at the central zone (3.8 per 10 microns membrane), but there was a significant increase along the apical and lateral surfaces of the equatorial epithelium compared to that of the central epithelium, although the overall number was considerably smaller. In the lens fibers, CPs and CVs were usually found within 2-3 superficial layers of fiber cells. The number of CPs and CVs along the basal membrane of young fibers at the post-equatorial region (3.1 per 10 microns membrane) was 3-fold greater than that of the mature fibers at the posterior polar area (1 per 10 microns membrane). Thus, CPs and CVs along the entire basal membrane showed a gradual decrease in number from the anterior (and equatorial) regions to the posterior polar surface of the lens. WGA-HRP experiments showed that approximately 80% of tracer-carrying pits and vesicles were also found along the basal surface of the equatorial epithelium. This study suggests that a polarized distribution of CPs and CVs along the basal surface of epithelium and superficial fiber cells may facilitate receptor-mediated endocytosis of important macromolecules directly from the aqueous humor and vitreous body into metabolically active lens cells.

Effects of naloxone on the changes of pain threshold and contents of monoamine neurotransmitters in rat brain induced by EA

5-HT content in medulla oblongata plus pons and DA level in brain stem obviously increased, while NA concentration in telencephalon markedly decreased in EAA. A previous injection of naloxone, a blocker of opiate receptor, could partially inhibit the EAA, abolish the effects of EA's increasing the 5-HT content in the medulla oblongata plus pons and the DA level in the brain stem, and decrease the NA level in the diencephalon after EA. These results indicate that EA may mediate the metabolism of the central monoamine neurotransmitters partially via opiate receptor to exert its analgesic effect.

Analysis of rice Act1 5' region activity in transgenic rice plants

The 5' region of the rice actin 1 gene (Act1) has been developed as an efficient regulator of foreign gene expression in transgenic rice plants. To determine the pattern and level of rice Act1 5' region activity, transgenic rice plants containing the Act1 5' region fused to a bacterial beta-glucuronidase (Gus) coding sequence were generated. Two independent clonal lines of transgenic rice plants were analyzed in detail. Quantitative analysis showed that tissue from these transgenic rice plants have a level of GUS protein that represents as much as 3% of total soluble protein. We were able to demonstrate that Act1-Gus gene expression is constitutive throughout the sporophytic and gametophytic tissues of these transgenic rice plants. Plants from one transgenic line were analyzed for the segregation of GUS activity in pollen by in situ histochemical staining, and the inheritance and stability of Act1-Gus expression were assayed in subsequently derived progeny plants.

[Releasing properties of water soluble drug in internal water phase of W/O/W multiple emulsions]

A stable water/liquid paraffin system water-in-oil-in-water (W/O/W) multiple emulsion was prepared by the two-step procedure of emulsification using a variety of nonionic emulsifying agents, such as Span 80 and Tween 20. After comparison of the releasing properties of such water soluble drugs as cefadroxil, cephradine, 4-aminoantipyrine and antipyrine which were entrapped separately in the inner aqueous phase of the W/O/W multiple emulsion, a large difference was observed. It was ascertained that the difference in these releasing properties was due to no physical rupture by the microscopic observation and the results of the release test of W/O/W multiple emulsion with two kinds of drugs entrapped simultaneously in an inner aqueous phase. This reason was presumed to be dependent on permeation in the oily phase of the drug itself. It was proved that the differences of releasing properties tended to depend on the molecular weight and were closely related to the drug concentration of outer aqueous phase of W/O/W multiple emulsion containing the drug in both aqueous phases prepared as an experimental model. Therefore, two possible mechanisms for the releasing of drugs in W/O/W multiple emulsion may be interpreted as follows: the first is that the mixed and inversed micelles formed by Span 80 and Tween 20 agents in the oily phase act as a carrier of drugs, and the second is that drug molecules diffuse through small pore existing in very thin lamella of the emulsifying agents partially formed in the oil layer owing to the fluctuation of the thickness.

Image processing of human corneal endothelium based on a learning network

We applied a learning network to a cell's boundary detection of human corneal endothelium photomicrographs measured by specular microscopy. Interconnections between units in our model are constrained to be locally space invariant to meet space-invariant processing. The neural network was trained to extract the cell's boundary by showing part of the photomicrograph and its subjective boundary image, which is an outline drawing made by hand. After training, the network showed good performance with the microphotograph that was not trained. Internal representations of the network were also studied.

The role of oxygen free radicals in myocardial ischemia/reperfusion injury

A series of experiments have been done to investigate the role of oxygen free radicals in ischemia/reperfusion injury. The following results were found: Myocardial MDA content increased significantly after post-ischemic reperfusion in vivo and in vitro. A blockade of the xanthine oxidase pathway for free radical generation could provide effective protection against ischemia/reperfusion injury. Exogenous reactive oxygen intermediates H2O2, .OH and O2- could induce changes in the contractility and electrophysiological properties of myocardial cells similar to those seen in ischemia/reperfusion. An outburst of free radical generation was detected by ESR spectroscopy at low temperature (-173 degrees C) and with the spin trapping technique during the very early phase of reperfusion. The authors emphasize the important role of free radicals in the pathogenesis of myocardial ischemia/reperfusion injury.

A research for the relationship between human papillomavirus and human uterine cervical carcinoma. II. Molecular genetic and ultrastructural study on the transforming activity of recombinant retrovirus containing human papillomavirus type 16 subgenomic sequences

In order to elucidate the role of HPV-16 in the development of genital cancer, NIH3T3 cells were transfected by HPV-16 whole genome and its two early genes, E6-E7. Besides ordinary calcium phosphate/DNA coprecipitation technique, a newly designed recombinant retrovirus containing the HPV-16 genome or subgenomes was used to infect cells for transfer of the target genes. The transforming activities have been demonstrated to be most efficient when a bioengineering technique of this kind is used. HPV-16 DNA was proved to have transforming potential for NIH3T3 cells, and the DNA of HPV-16 was proved to undergo multisite integration into transformed cells and nude mice tumour cells. The E6-E7 open reading frames are sufficient for transforming NIH3T3 cells independently in vitro, which implies that E6-E7 open reading frames are transforming genes or even viral oncogenes of HPV-16. The RNA transcribed by the E6-E7 of HPV-16 was expressed in transformed cells and in tumour cells of nude mice. The use of a recombinant retrovirus for gene transfer in this study is much more efficient than that of calcium phosphate/DNA coprecipitation. The lack of a tissue-culture system suitable for HPV replication in vitro makes HPV gene recombination into a specially engineered retrovirus for viral-mediated gene transfer of particular significance for the possible application of viral carcinogenesis, both in vitro and in vivo, for basic and clinical research.

A research for the relationship between human papillomavirus and human uterine cervical carcinoma. I. The identification of viral genome and subgenomic sequences in biopsies of Chinese patients

Biopsies from 318 cases with squamous cell carcinoma of the uterine cervix, 48 with cervical and vulvar condylomata, 14 with cervical intraepithelial neoplasia (CIN), 34 with chronic cervicitis and 24 with normal cervical epithelium were collected from different geographic regions with different cervical cancer mortalities. The DNA.DNA dot-blot and Southern blot hybridization results show that there is a close relationship between HPV-16 and the uterine cervical squamous cell carcinoma in China. One very interesting observation is that the finding of HPV-16-homologous DNA differs significantly among five geographic regions, and corresponds with the mortalities from cervical cancer of these five regions. HPV-11 was found mainly in benign lesions. The rate of detection of HPV-16 in Chinese women increased from 8.3% in normal cervical epithelium to 20% in chronic cervicitis, 28% in cervical condyloma, 50% in CIN and 60.4% in cervical cancer. It is suggested that HPV-16 infection may be an etiological factor in the development of human cervical carcinoma. From the results of Southern blot hybridization, it appeared that HPV-16 DNA had been integrated into the genome of the host cell in cervical cancer. Whereas the HPV-16 DNA sequence was only present as an episome in normal cervical epithelium and cervical benign lesions. The rate of occurrence of E6-E7 genes is the highest (88.9%) compared with that of other subgenomic fragments of HPV-16 in specimens of human cervical cancer in China. This implies that E6 and E7 may be the oncogenic genes of HPV-16 and play an important role in the carcinogenesis of human cervical epithelial cells. The amplification and rearrangement of the c-myc protooncogene are closely associated with the occurrence of cervical cancer. The results presented here revealed that the activated c-myc oncogene may cooperate with HPV-16 in the carcinogenic processes.

[A clinical and CT analysis of 28 cases of spontaneous cerebellar hemorrhage]

28 cases of spontaneous cerebellar hemorrhage diagnosed with CT scanning were analysed. Based on the findings of the CT scans as well as the clinical manifestations it could be recognized that there were 3 types of cerebellar hemorrhage: 1. Vermis hemorrhage usually complicated with rupture into the fourth ventricle needed immediate operation for alleviating and checking the ventricular hemorrhage and hydrocephalus. 2. Massive hemorrhage in the cerebellar hemisphere resulting in forming a hematoma of less than 10 ml and larger than 5 ml could be treated conservatively under close observation, but for those case with larger hematomas, operative treatment would be mandatory. 3. Small hematomas of less than 5 ml in the cerebellar hemispheres could also be treated conservatively. The authors emphasized that acute obstructive hydrocephalus should be considered to be an important factor in leading to a fatal outcome in these cases.