Clinical neuroimmunology

Clinical research has focused on autoimmune disease (AID) for a couple of decades. More sensitive and specific methods have been developed for neuroimmunological research. Gamma fraction bands (bands separated by electrophoresis and visualized by amino black staining) and IgG fraction bands (bands separated by iso-electric focusing and visualized by immunostaining) are used instead of oligoclonal bands. Myasthenia gravis (MG) mainly involves acetylcholine receptors of the postsynaptic membrane at the neuromuscular junction. Myasthenia gravis has been considered to be a generalized AID, because 7% of patients with myasthenia gravis associate with other AIDs and more than one autoimmune antibody is detected in 52.5% patients with myasthenia gravis. Pyramidal signs in myasthenia gravis patients are described; the possible mechanism may at least be partly due to the acetylcholine receptor antibody. P2 protein and its antibody are studied in patients with acute and chronic inflammatory demyelinating polyneuropathy.

The evolution and current status of China's Tibetan population

"Through analyses on the changes in the mortality rate, total population size, regional population distribution, gender-specific age structure, and the population nationality structure in major habitats of Tibetan residents since the founding of the People's Republic, this article shows that the Tibetan population size has been on the steady increase, mortality rate has seen marked decrease, and the rights of existence of Tibetan people have been fully guaranteed since the establishment of the Communist Government in 1949."

[Prognostic factors affecting the results of surgical treatment of cervical cancer]

From October, 1963 to December, 1992, 1,213 cases with cervical cancer were treated surgically in our hospital, among whom 922 cases, including 305 in stage 0, 123 in stage IA, 212 in stage IB, 265 in stage IIA, 17 in stage IIB, were operated before February, 1990. Among the 617 evaluable cases, excluding those in stage ), the five-year survival rates were 95.1% in stage IA, 91.0% in stage IB, 83.1% in stage IIA and 59.0% in stage IIB, respectively. The results showed that cervical tumour greater than 4 cm in diameter, invasion in muscular layers, lower degree of differentiation and pelvic lymph nodes metastasis would lead to worse therapeutic effects. The method of pelvic lymphadenectomy, pathological types, and ages of the patients, however, did not at all correlate with the survival rates of the patients. For those who have above-mentioned risk factors active adjuvant treatments are indicated.

[Endoscopic sinus surgery, clinical aspect with 69 cases]

Sixty-nine patients (121 sides) received endoscopic sinus surgery between May, 1993 and October, 1994. All of the patients exhibited following clinical signs: bilateral or unilateral nasal polyps and paranasal sinusitis. There were 43 men and 26 women, ranging in age from 14 to 68 years. Among the patients, 14 (25 sides) were treated with functional ethmoidectomy; 33 (59 sides) with total ethmoidectomy; and 21 (36 sides) with sphenoethmoidectomy. 23 patients (36 sides) were treated simultaneously with radical maxillary sinus surgery. According to the data of postoperative follow-up, nasal obstruction disappeared completely in 57 cases (57/59); headache remitted in 51 (51/56); and 35 (35/54) were free of purulent nasal discharge. No severe complications were observed. The incidence of residual and recurrent polyp were 12.39% (15/121 sides). The curative effect of endoscopic sinus surgery was analysed. The indications of operation, the preoperative CT scan of paranasal sinuses, and the endoscopic techniques were discussed.

Preparation of Tyr-C-peptide from genetically altered human insulin precursor

C-peptide radioimmunoassay (C-peptide RIA) is widely used in determination of pancreatic B-cell secretion activity. 125I labeled Tyr-C-peptide is indispensable in C-peptide RIA kit. Herein we discuss a way of obtaining recombinant Tyr-C-peptide. Arg32Tyr human pro-insulin mutant (R32Y-proinsulin) gene was constructed by site-directed mutagenesis and overexpressed in Escherichia coli. Purified R32Y-proinsulin was converted to insulin and Tyr-C-peptide by trypsin and carboxypeptidase B codigestion. Tyr-C-peptide was isolated through reverse-phase HPLC (RP-HPLC) and identified by C-peptide RIA and amino acid analysis.

Expression of type V adenylyl cyclase is required for epidermal growth factor-mediated stimulation of cAMP accumulation

Previously, this laboratory has demonstrated that epidermal growth factor (EGF) increases adenylyl cyclase activity in cardiac membranes and elevates cAMP accumulation in hearts and cardiac myocytes. Since EGF does not increase cAMP accumulation in all tissues, we investigated the possibility that the expression of a specific isoform of adenylyl cyclase (AC) was necessary to observe EGF-elicited stimulation of cAMP accumulation. HEK 293 cells were transfected with different isoforms of AC, and the ability of EGF to increase AC activity as well as elevate cAMP accumulation was determined. In cells transfected with AC I, II, V, and VI cDNAs, neither the expression nor the amount of the two isoforms of Gs alpha (45 and 52 kDa) were altered. Similarly, EGF-elicited phosphorylation of cellular proteins on tyrosine residues in various transfectants was unaltered. However, EGF increased AC activity and elevated cAMP accumulation only in cells expressing the rat and canine ACV. EGF did not alter either AC activity or cAMP accumulation in cells overexpressing types I, II, and VI isozymes. As assessed by the ability of an anti-Gs alpha antibody to obliterate the effect, stimulation of AC activity in AC V transfectants involved the participation of Gs alpha, a finding consistent with previous data concerning EGF effects on cardiac AC (Nair, B. G., Parikh, B., Milligan, G., and Patel, T. B. (1990) J. Biol. Chem. 265, 21317-21322). Thus we conclude that the expression of AC V isoform confers specificity to the ability of EGF to stimulate AC activity.

Theory of the effect of the laser-field-induced index grating on wavelength increment and gain saturation in semiconductor lasers

A simple theory considering the laser-field-induced complex index grating is presented for what is to the author's knowledge the f irst time to explain and calculate the observed wavelength increment in semiconductor lasers as their output light power increases and to calculate the gain saturation in semiconductor lasers. The calculation results agree with the commonly accepted results.

Three-dimensional structure of CA1 pyramidal cells in rat hippocampus--optical recording of LSM and computer simulation of fractal structure

The optical recording of three-dimensional (3-D) reconstruction of CA1 pyramidal cells was derived from the studies on the CA1 region of the hippocampus in adult male Wistar rats. The recording was produced by the Confocal Laser Scan Microscope (LSM-10). The attemption was to outline the morphological neural network of CA1 pyramidal cells organization, following the trail of axo-dendritic connections in 3-D spatial distributions among neurons. The fractal structure of neurons with their dendritic and axonal trees using fractal algorithm was noticed, and 2-18 simulated cells were obtained using PC-486 computer. The simulational cells are similar in morphology to the natural CA1 hippocampal pyramidal cells. Therefore, the exploitation of an advanced neurohistological research technique combining optical recording of the LSM-10 and computer simulation of fractal structure can provide the quantitative fractal structural basis for chaosic dynamics of brain.

Simple theory on the effect ofn photon-density longitudinal nonuniformity in a two-section semiconductor laser

A simple theory is presented to study the operation state of a two-section semiconductor laser by the consideration of the difference between the two photon densities in the two sections. It is shown that the ratio of the two photon densities in the two sections can be 1.6 or even larger and is a function of the reflectivity of the laser facets. This photon-density ratio affects the photon-density level of bistable or pulsation operation, as well as the width of the bistable-operation range of the laser. However, the threshold condition and the stable-operation criterion of the laser are not affected.

The expression pattern of the Distal-less homeobox-containing gene Dlx-5 in the developing chick limb bud suggests its involvement in apical ectodermal ridge activity, pattern formation, and cartilage differentiation

Here we report the isolation from a chick limb bud cDNA library of a cDNA that contains the full coding sequence of chicken Dlx-5, a member of the Distal-less (Dlx) family of homeobox-containing genes that encode homeodomains highly similar to that of the Drosophila Distal-less gene, a gene that is required for limb development in the Drosophila embryo. The expression pattern of Dlx-5 in the developing chick limb bud suggests that it may be involved in several aspects of limb morphogenesis. Dlx-5 is expressed in the apical ectodermal ridge (AER) which directs the outgrowth and patterning of underlying limb mesoderm. During early limb development Dlx-5 is also expressed in the mesoderm at the anterior margin of the limb bud and in a discrete group of mesodermal cells at the mid-proximal posterior margin that corresponds to the posterior necrotic zone. These mesodermal domains of Dlx-5 expression roughly correspond to the anterior and posterior boundaries of the progress zone, the group of highly proliferating undifferentiated mesodermal cells underneath the AER that will give rise to the skeletal elements of the limb and associated structures. The AER and anterior and posterior mesodermal domains of Dlx-5 expression are regions in which the homeobox-containing gene Msx-2 is also highly expressed, suggesting that Dlx-5 and Msx-2 might be involved in regulatory networks that control AER activity and demarcate the progress zone. In addition, Dlx-5 is expressed in high amounts by the differentiating cartilaginous skeletal elements of the limb, suggesting it may be involved in regulating the onset of limb cartilage differentiation.

Immunoregulatory effects of the herba Epimediia glycoside icariin

The in vitro effects of the Chinese Herba Epimediia glycoside icariine (ICA), a chinese herbal extract, on human immune responses were investigated. ICA induced a weak and delayed proliferation of peripheral blood mononuclear cells from healthy donors when compared to phytohemagglutinin. Both T- (TCR alpha beta+) and B cells were the ICA-responding cells. Within T-cells, the relative proportion of CD4-8+ cells increased but that of CD4+8- cells decreased. ICA in certain concentrations could increase lymphokine-activated killer cell (LAK) activity (0.1 to 1.0 microgram/ml) in both tumor patients and healthy donors, and natural killer cell (NK) activity (1.0 to 5.0 micrograms/ml) in tumor patients. Moreover, ICA stimulated the production of tumor necrosis factor-alpha in monocytes from healthy donors. These findings provide evidence that ICA could be applied to adoptive immunotherapy. Generation of LAK cells in presence of an appropriate dose of ICA might be superior to interleukin-2 alone.

Transforming growth factor-beta 1 modulates adenylyl cyclase signaling elements and epidermal growth factor signaling in cardiomyocytes

Studies presented in this report were designed to investigate the effects of transforming growth factor-beta 1 (TGF-beta 1) on epidermal growth factor (EGF)-mediated stimulation of cAMP accumulation in cardiac myocytes and elucidate the mechanism(s) involved in this modulation. TGF-beta 1 (20 pM) treatment of cardiac myocytes, in a time-dependent manner, decreased the ability of EGF (100 nM) to increase cAMP accumulation. Significant attenuation of EGF-elicited cAMP accumulation was observed 2 h after exposure to TGF-beta 1 and 18 h after addition of TGF-beta 1, the ability of EGF to increase cAMP accumulation was completely obliterated. TGF-beta 1 neither decreased immunoprecipitable EGF receptors in membranes from cardiomyocytes nor altered the specific binding of [125I]EGF to cardiomyocyte membranes. However, TGF-beta 1 decreased the ability of EGF to phosphorylate membrane proteins on tyrosine residues. TGF-beta 1 treatment of cardiomyocytes also decreased the ability of forskolin to augment cAMP accumulation in intact cells and stimulate adenylyl cyclase activity. Similarly, in membranes of TGF-beta 1-treated cells, neither isoproterenol nor EGF stimulated adenylyl cyclase activity. Interestingly, as assessed by the ability of A1F4- to stimulate adenylyl cyclase, TGF-beta 1 did not alter the coupling between Gs and catalytic subunits. Likewise, TGF-beta 1 did not alter the functional activity of the inhibitory regulatory element of the system, Gi. Western analysis of cellular proteins revealed that TGF-beta 1 did not alter the amounts of Ga alpha, Gi alpha 2, and Gi alpha 3. We conclude that TGF-beta 1 attenuates EGF-elicited cAMP accumulation in cardiomyocytes, in part, by decreasing the EGF receptor kinase function and that TGF-beta 1-mediated alterations in the activity of adenylyl cyclase catalytic subunit also contribute toward the regulation of adenylyl cyclase by various agonists.

[Placental ureaplasma urealyticum infection and low birth weight]

Ureaplasma urealyticum (UU) infection during pregnancy may result in poor outcome. Placentae from 116 normal healthy pregnancies were cultured for UU with a recovery rate of 28.45%. 94 cases ended by normal vaginal delivery had a UU positive rate of 29.79%. The UU positive rate of 22 placenta from cases by cesarean section was 22.73%. The 2 positive rates showed no difference of significance (P > 0.05). This result indicated that UU infection of the placenta was present before passing through the birth canal and not due to contaminant during delivery. The birth weight of the neonates with positive UU infection was on the average 2,919g, while that in the negative UU cases was 3,490g, being 571g higher than in the positive group (P < 0.01). This study showed that placental infection with UU is associated with a low birth weight.

Effect of levonorgestrel-releasing intrauterine device on hormonal profile and menstrual pattern after long-term use

In the present study 14 women after 6 years' use of levonorgestrel-releasing IUD were investigated for the changes of LH, progesterone (P), estradiol (E2), prolactin (PRL) and serum binding globulin (SHBG) in relation to the levonorgestrel levels throughout a segment of 26-40 days with the aim of comparing the hormonal profiles with those during the first year of use of Lng-IUD. Ultrasound scanning was used to follow the development of follicles along with the RIA measurement of hormones. The results of serum LH, P and E2 showed ovulation in 11 cases with either normal menstrual cycles (5 cases), prolonged or irregular cycles (4 cases) or with amenorrhea for 2-3 years (2 cases). One case showed insufficiency of luteal function and 2 cases showed anovulation but with follicular hyperactivity. Higher percentages of ovulatory cycles (78.5%) were found after 6 years of use. No case of complete suppression of ovulation was found. Anovulatory cycles only constituted 14.3%. Clinically, the development of follicles followed by ultrasound scanning further confirmed the hormonal findings. The persistent enlargement of follicles coincided with high levels of E2. After 6 years of use, the serum levels of levonorgestrel were still maintained at mean levels of 314.26 pmol/L and 470.63 pmol/L in the ovulatory and anovulatory groups, respectively. It is concluded that over two-thirds of the cases have ovulatory cycles after long-term use of Lng-IUD; the contraceptive effect is mainly due to its local action on the endometrium, with much less effect on the ovarian function.

Alterations in messenger RNA encoding atrial natriuretic hormone receptor A and C subtypes during hepatic regeneration

Previously, we demonstrated that, 48 hours after partial hepatectomy, in the regenerating liver the number of both atrial natriuretic hormone (ANF) receptor subtypes, the guanylyl cyclase-linked and ANF-C receptors, is increased twofold. Subsequently, we demonstrated that activation of ANF-C receptors inhibits growth of hepatocytes. Therefore, studies were performed to determine whether, during hepatic regeneration, the increase in ANF receptor subtypes is accompanied by an increase in their respective transcripts. Our data demonstrate that in the normal and regenerating rat liver, the predominant guanylyl cyclase-linked ANF receptor is of the ANF-A subtype. Moreover, messenger RNA (mRNA) encoding the ANF-A and ANF-C receptors are transiently increased after surgery; the levels of mRNA encoding both receptor subtypes remain unchanged in livers of sham-operated animals. ANF-A receptor mRNA is maximally increased 12 hours after partial hepatectomy, whereas the maximal increase in ANF-C receptor mRNA is observed between 0.5 hour and 4 hours after hepatectomy. The increase in ANF-C receptor transcript is accompanied by increased expression of protein, 4 hours after hepatectomy. However, the ANF-C receptor protein is also elevated 48 hours after partial hepatectomy when ANF-C receptor mRNA levels are not different from controls. Likewise, although ANF-A receptors are increased when hepatic levels of mRNA encoding the protein are maximally elevated, the maximal increase in ANF-A receptor protein occurs at times when transcript levels are low and similar to those in sham-operated controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Constitutive MAP kinase phosphatase (MKP-1) expression blocks G1 specific gene transcription and S-phase entry in fibroblasts

MAP kinase (mitogen activated protein kinase) represents a ubiquitously expressed family of kinases whose long term activation via phosphorylation is essential for the mitogenic response in fibroblasts. Two family members, p42 and p44 MAP kinase are cytosolic proteins in quiescent cells, but become nuclear following mitogenic stimulation. Inactivation of MAP kinases occurs via a specific phosphatase, MKP-1. Hence, we examined the localisation of this phosphatase, to determine the cellular site of MAP kinase inactivation. Transient transfection of CCL39 fibroblasts with epitope-tagged MKP-1 showed the protein to be entirely nuclear in both quiescent and mitogen stimulated cells, whereas a catalytically inactive mutant in which the essential cysteine was mutated to serine (MKP-1CS) was predominately cytoplasmic and again serum stimulation failed to alter the protein's localisation. Expression of either wild type or inactive MKP-1 did not alter the cytosolic localisation of p44 MAP kinase in quiescent cells nor the ability of MAP kinase to translocate to the nucleus following mitogen stimulation. Expression of wild type MKP-1 inhibited serum stimulated early (c-fos promoter) and late (dhfr promoter) transcriptional events as well as entry into S-phase. This inhibition was reversed by the co-expression of an active MAP kinase. We conclude that in the continual expression of MKP-1, the cellular localisation of MAP kinase is unaffected and that inactivation of MAP kinase by MKP-1 is a nuclear process leading to the inhibition of cell division.

African swine fever virus gene j13L encodes a 25-27 kDa virion protein with variable numbers of amino acid repeats

The African swine fever virus (ASFV) j13L gene encodes a 177 amino acid protein (19.0 kDa) with a putative transmembrane domain between residues 32 and 52. There is a potential signal peptide cleavage site at residue 54 and several possible motifs for phosphorylation and myristylation. Rabbit antisera raised against a synthetic peptide from the C terminus of the j13L ORF identified proteins of 25-27 kDa in cells infected with a recombinant vaccinia virus expressing the j13L ORF, in ASFV-infected cells and in purified extracellular ASF virions. In ASFV-infected cells the j13L protein was expressed late during infection and exhibited size variation (25-27 kDa) between the different ASFV strains. Nucleotide sequence analysis of the gene in these strains showed that these size differences were due to variation in the number and sequence of tandemly repeated amino acid repeats. Although ASFV-infected animals made antibodies to the j13L protein, no protection was observed when pigs were vaccinated with a recombinant vaccinia virus expressing the j13L ORF.

A method of determining the in vivo drug release rate constant of sustained-release preparation

Assuming a one-compartment model and first-order processes for drug release, absorption, and elimination, a new equation to describe the fraction of drug to be absorbed (1-Ft) for a sustained-release product is derived. Based on this equation, when In(1-Ft) vs. time is plotted, the slopes yield the drug release rate constant (Kr), the drug absorption rate constant (Ka), and two intercepts that are a mixed function of Ka, Kr, and the fraction of sustained-release (Fs). The accuracy of this equation to generate pharmacokinetic parameters, such as Ka, Kr, Fs, and the bioavailability-volume of distribution ratio (FD/V) was tested by fitting this equation to multiple simulated plasma concentration-time data (5 sets errorless and 75 sets errant data). The absolute percentage error of Ka and FD/V estimated by this equation is much less than that of traditional polyexponential equation, whereas the absolute percentage error of Kr estimated by this equation is statistically significantly less than that of traditional polyexponential equation. Furthermore, with this equation, it is easier to estimate Fs than with traditional equation. An application of this equation in generating these parameters is illustrated for a quinidine sustained-release dosage form-quinidex.

Monte Carlo simulation of radon emanation from dry building materials

Prediction of radon release from building materials is a general problem. Since it is impractical to follow each recoil radon path and measure the surface area of porous texture by experimental methods, a powerful computer simulation approach is conducted in this paper. The Monte Carlo simulation program TRIM, based on the momentum and energy conservation of the ion transport in matter, is modified to simulate the recoil path in a 3-D frame. A follow-up Monte Carlo program was established further to calculate the detailed recoil range distribution and the recoil probability (emanating power). The powerful Turning Bands Method (TBM) of random field is applied to simulate the 3-D porous texture based on the porosity and the correlation function of the porous texture. Based on the simulated porous texture, the fractal dimension of the surface is calculated and used to calculate the effective surface area for radon recoil. The relations between the air buffer thickness, embedding effect of recoil, and the measuring scale of the surface area for the porous texture are discussed and numerically calculated. After these calculations are performed, the relations between the emanating rate, surface area, material density, and porosity are established to calculate the radon emanation rate from porous materials. This paper provides a clear theoretical picture of the mechanism of radon release from the building materials. It has also potential application to the recoil release calculations of other radioactive elements from solid materials.

A region in the cytosolic domain of the epidermal growth factor receptor antithetically regulates the stimulatory and inhibitory guanine nucleotide-binding regulatory proteins of adenylyl cyclase

Epidermal growth factor (EGF) stimulates adenylyl cyclase in the heart via activation of the stimulatory GTP-binding protein Gs. Therefore, employing peptides corresponding to regions in the cytosolic domain of the EGF receptor, we have investigated the ability of sequences within the EGF receptor to activate Gs. A 13-aa peptide (EGFR-13) corresponding to the juxtamembrane region in the cytosolic domain of the EGF receptor stimulated GTP binding and GTPase activity of Gs. This peptide did not stimulate GTP binding to Gi but increased the GTPase activity of this protein. Additionally, phosphorylation of the protein kinase C site (threonine residue) within EGFR-13 decreased the ability of the peptide to stimulate Gs and increase GTPase activity of Gi. Further, in functional assays of Gs employing S49 cyc- cell membranes, EGFR-13 increased the ability of Gs to stimulate adenylyl cyclase; phospho-EGFR-13 and a 14-aa peptide corresponding to a sequence in the cytosolic domain of the EGF receptor did not alter the functional activity of Gs. Hence, the juxtamembrane region of the EGF receptor can activate Gs and, by stimulating GTPase activity of Gi, inactivates this latter G protein. Phosphorylation of the threonine residue within this region attenuates the activity of the peptide as a modulator of G-protein function.