TGF beta signals through a heteromeric protein kinase receptor complex

Transforming growth factor beta (TGF beta) binds with high affinity to the type II receptor, a transmembrane protein with a cytoplasmic serine/threonine kinase domain. We show that the type II receptor requires both its kinase activity and association with another TGF beta-binding protein, the type I receptor, to signal growth inhibition and early gene responses. Receptors I and II associate as interdependent components of a heteromeric complex: receptor I requires receptor II to bind TGF beta, and receptor II requires receptor I to signal. This mode of operation points to fundamental differences between this receptor and the protein-tyrosine kinase cytokine receptors.

[Anti-lipid peroxidation and protective effects of phenytoin sodium on ischemic myocardium of mice]

Isoproterenol (Iso, 20 mg.kg-1 x d-1 x 2 d) induced widespread and severe myocardial damages at ultrastructural level, decreased the myocardial Se-glutathione peroxidase (Se-GSH-Px) and superoxide dismutase (SOD) activities, increased the serum creatine phosphokinase (CPK) concentration and myocardial malondialdehyde (MDA) content. Phenytoin sodium (Phe) 15 or 30 mg.kg-1 ip pretreatment diminished the CPK release and MDA production, protected the Se-GSH-Px activity in the Iso-induced damage of mouse heart. The pretreatment with 30 mg.kg-1 abated the reduction of SOD activity. However, Phe 15 mg.kg-1 did not show such an effect. Phe (15 or 30 mg.kg-1) reduced the ultrastructural cardiotoxicity of Iso, and the membrane structure of ischemic myocardium was protected. The protective effects of verapamil pretreatment 3 mg.kg-1 ip were weaker than those of Phe on ultrastructural changes, but biochemical changes were similar to those of Phe. The results suggested that Phe possessed anti-lipid peroxidation and protective effects on ischemic myocardium.

The relationship between intracardiovascular smoke-like echo and erythrocyte rouleaux formation

Intravascular smoke-like echo always appears in regions of stasis, but the exact mechanism of its production is unclear. We investigated its appearance in relation to erythrocyte rouleaux formation. To study this relationship we performed a series of in vitro and animal experiments. In the in vitro study, we observed an erythrocyte suspension by ultrasonography and found it to be echo-free. Under the microscope, red blood cells were observed in a dispersed state. If an equal amount of lymphocyte separation solution was added to the suspension, smoke-like echo appeared, and red blood cells were seen in a rouleaux pattern. In animal (mongrel dogs) experiments, under physiologic conditions with normal blood flow velocity, all cardiac cavities and the inferior vena cava were echo-free. When stasis was induced experimentally in the inferior vena cava, red blood cells aggregated to form rouleaux and smoke-like echo appeared. On resumption of normal blood flow, the rouleaux dispersed to form erythrocytes again. The mechanism of production of intracardiovascular smoke-like echo is closely related to the formation of erythrocyte rouleaux. When rouleaux are formed, they become larger and appear nearer or larger than the ultrasonic wavelength. Thus reflections are produced and smoke-like echo appears.

Expression cloning of TGF-beta receptors

Using a powerful expression cloning method in COS cells, we have cloned the TGF-beta types II and III receptors. The type III TGF-beta receptor is a membrane-bound proteoglycan with a core protein of about 110 kDa. Stable expression of the type III receptor in L6 myoblasts leads to an apparent increase in the ability of the type II receptor to bind iodinated TGF-beta 1. The cloned type II receptor has a predicted protein core of about 60 kDa with a cysteine-rich extracellular domain, a single transmembrane domain, and a functional serine/threonine kinase domain that is homologous to the activin receptor and to the C. elegans protein daf-1. These results implicate serine/threonine phosphorylation as an important mechanism of TGF-beta action.

Unit activity to click CS changes in dorsal cochlear nucleus after conditioning

Recordings were made of single unit activity (n = 360 units) from the dorsal cochlear nucleus of cats. Different patterns of activity were elicited by acoustic stimuli before and after Pavlovian conditioning. The peak response to a forward paired click conditioned stimulus (CS) increased whereas that to a backward paired hiss discriminative stimulus (DS) did not. The percentage of units responding to the CS increased from 34% to 46% after conditioning. The findings do not support the widely accepted hypothesis that learning has no effect on transmission through the first brain stem relay of the auditory system and indicate, instead, that the cochlear nucleus can participate in complex adaptive acoustic signal processing.

Biplane transesophageal echocardiography: an anatomic-ultrasonic-clinical correlative study

In 427 subjects TEE was performed with either a uniplane or biplane transducer; in seven cadavers the cardiac anatomic segments were observed in several levels and directions. Nine transverse and six longitudinal views were compared with the corresponding cardiac anatomic segments. Based on this correlative study, the levels of segments, insertion depth, anatomic structure identification, image characteristics, clinical applications, and the advantages as well as the limitations of biplane TEE are discussed.

Expression cloning of the TGF-beta type II receptor, a functional transmembrane serine/threonine kinase

A cDNA encoding the TGF-beta type II receptor protein has been isolated by an expression cloning strategy. The cloned cDNA, when transfected into COS cells, leads to overexpression of an approximately 80 kd protein that specifically binds radioiodinated TGF-beta 1. Excess TGF-beta 1 competes for binding of radioiodinated TGF-beta 1 in a dose-dependent manner and is more effective than TGF-beta 2. The predicted receptor structure includes a cysteine-rich extracellular domain, a single hydrophobic transmembrane domain, and a predicted cytoplasmic serine/threonine kinase domain. A chimeric protein containing the intracellular domain of the type II receptor and expressed in E. coli can phosphorylate itself on serine and threonine residues in vitro, indicating that the cytoplasmic domain of the type II receptor is a functional kinase. This result implicates serine/threonine phosphorylation as an important mechanism of TGF-beta receptor-mediated signaling.

Expression cloning and characterization of the TGF-beta type III receptor

The rat TGF-beta type III receptor cDNA has been cloned by overexpression in COS cells. The encoded receptor is an 853 amino acid protein with a large N-terminal extracellular domain containing at least one site for glycosaminoglycan addition, a single hydrophobic transmembrane domain, and a 41 amino acid cytoplasmic tail with no obvious signaling motif. Introduction of the cDNA into COS cells and L6 myoblasts induces expression of a heterogenously glycosylated 280-330 kd protein characteristic of the type III receptor that binds TGF-beta 1 specifically. In L6 myoblasts lacking the endogenous type III receptor, expression of the recombinant receptor leads to an increase in the amount of ligand bound and cross-linked to surface type II TGF-beta receptors. This indicates that the type III receptor may regulate the ligand-binding ability or surface expression of the type II receptor.

The dentate nucleus is a short-latency relay of a primary auditory transmission pathway

Recordings of unit activity showing 4-6 ms latency responses to a click stimulus provided evidence that the dentate nucleus could function as a short-latency auditory relay. On the basis of these findings, plus fiber fillings from injections of phaseolus leucoagglutinin into the dentate, a new auditory pathway between dorsal and ventral cochlear nuclei, dentate nucleus, and rostral thalamus is proposed. The pathway could provide direct, short-latency transmissions to the motor cortex that bypass the classical auditory receptive cortex.

Biplane transesophageal echocardiography: imaging sections and anatomic segments

In order to recognize correctly the images of transesophageal echocardiography (TEE), in 410 subjects TEE was performed with uniplane or biplane transducer, and in 7 corpses the cardiac anatomic segments were observed, at various levels and in different directions, 9 transverse and 6 longitudinal views were compared with the corresponding cardiac anatomic segments. Based on this study, the authors reported the levels of segments, insertion depth, anatomic structure identification, image characteristics and clinical application of TEE, and the advantages of biplane TEE are discussed.

Hydrogen peroxide contrast hepatosonography

Hydrogen peroxide contrast hepatosonography (HPCH), a new technique, was developed for liver examination. On examination, 5-10 ml of 2-3% hydrogen peroxide was injected into the rectum through a dual-channel rubber tube. When hydrogen peroxide passed through the mucosa into the portal vein, the fast flowing contrast echoes were seen, and the liver parenchyma was covered by enhanced echoes. A total of 297 subjects were examined by HPCH with a successful contrast rate of 95.6%. In normal subjects, dense contrast echoes were visible throughout the liver. But in patients with hepatoma, hemangioma, cyst and abscess, contrast echo defects were noted. We conclude that HPCE is of great value in the differentiation of space-occupying lesions and measurement of portal circulation time and blood flow velocity in spite of its untoward reactions.

Preliminary study of quantification of regurgitant volume in mitral regurgitation by color Doppler echocardiography

A method for quantification of regurgitant volume in mitral regurgitation (MR) was studied. 31 cases of MR were investigated with color Doppler. The reliability of measuring velocity by Doppler and the influence of pressure gradient on MR were assessed and confirmed by experimental device. The results suggested that the best method in quantification of the regurgitant volume was "calibrating method" (r = 0.99; P less than 0.01), the next to the best was "volume method" (r = 0.74; P less than 0.01), whereas the regurgitant volume evaluated by multiplication of area, velocity and time was far from the actual regurgitant volume (r = 0.47; P greater than 0.05). The velocity of blood flow measured by Doppler is closely correlated to results obtained from experiments (r = 0.69; P less than 0.05). We believe that the ratio of back flow area and average area of left atrium calculated by Helmcke's method reflects the severity of the disease to a certain degree, bu there are many problems unsolved, e.g. the determination of the velocity of blood flow by color Doppler is dependent on the degree of brightness of coloration; the brighter the color, the quicker the speed it represents, whereas the darker coloration speaks for slower speed.

[Effect of fluoroquinolones made in China in the treatment of acute bacillary dysentery. A report of 212 cases]

212 cases of acute bacillary dysentery were treated with enoxacin and norfloxacin, another 15 cases were treated by chujunsheng. The cure rate in enoxacin group was 99.1%, in norfloxacin group 98.04% and in chujunsheng group 63.64%. The isolated pathogens were tested for susceptibility with disk diffusion and MIC determination. The results showed that both enoxacin and norfloxacin are better than gentamycin, ampicillin, chloramphenicol and trimethoprim-sulfamethoxazole. Side effects of enoxacin group and norfloxacin were noted in are 2.7% and 3.0% of the patients respectively. This study suggests that enoxacin and norfloxacin are highly effective, quite convenient for use and have few adverse reactions. They are considered to be drugs of choice for the treatment of acute bacillary dysentery.

Measurement and study of the nose and face and their correlations in the young adult of Han nationality

The measurement of 13 items in the face and nose of 220 young adults (110 males and 110 females) of the Han nationality between the ages of 18 and 21 years has been done in the Henan Province of China. The means and standard deviations have been obtained, and the significant differences in many items between males and females have been proved. Some items influencing outer nasal shape have been analyzed. The correlations between nose height, nose length, and morphologic facial height and physiognomic facial height have been discussed. The ratio and amount of nasal breadth to facial breadth and nasal breadth to interocular breadth have been compared and analyzed, and the differences among the different races and between the sexes have been explained.

Application of two-dimensional echocardiography in location of balloon of the Swan-Ganz catheter

Two-dimensional echocardiography was used to guide and locate the balloon of Swan-Ganz catheter during catheterization in 43 patients. The echoes of balloon appeared as a series of strong light spots, with a rate of detection of 100%. Under monitoring of two-dimensional echocardiography, the site of balloon and its moving route could be determined. The coincidence of echographic findings and X-ray findings showed that it can be used instead of X-ray monitoring to lessen irradiation during catheterization. The depth of catheter inserted was measured. The differential points between the echoes of balloon and tubing, the terminology of the balloon site in echocardiography and fluoroscopy, its clinical value and limitation are discussed.

Diagnosis and treatment of retrocaval ureter

34 cases of retrocaval ureter of our country, including 2 of our hospital, were studied. The embryologic pathology, diagnosis and treatment of the disorder are discussed. The choice of operative methods and 'vena cava supporter' are also described.

Progression to development of lymphoma in the thymus of AKR mice treated neonatally with SL 3-3 virus

All AKR mice develop thymic lymphoma between 60 and 90 days of age after neonatal treatment with the oncogenic retrovirus SL 3-3. At 40-50 days of age, in the normal-sized thymus of virus-treated mice, cells appear that produce lymphoma when inoculated intrathymically but not when inoculated s.c. These cells are designated as thymus-dependent (TD) lymphoma cells. TD cells progress to cells that form tumors after both intrathymic and s.c. inoculation; these are designated as thymus-independent (TI) lymphoma cells. In this report, we show that the TD and TI cells can be distinguished as two distinct cell populations. Experiments show that the TD cells reside within the immature CD4- CD8- thymocyte population of the virus-treated mice. In addition, we also show that CD4- CD8- thymocytes from SL 3-3 virus-treated mice do not mature in fetal thymic stromal rudiments. Using three-color flow cytometry to trace maturation of CD4- CD8- thymocytes after intrathymic inoculation into irradiated syngeneic hosts, disregulated thymocyte maturation of this population from virus-treated mice is demonstrated. Thus, altered maturation of and the appearance of TD lymphoma cells in, the most immature population of thymocytes appears to be a first step in a multistep process of thymic lymphomagenesis caused by SL 3-3 virus.

[Estimation of plasma protein C, protein S and antithrombin III in patients with chronic liver diseases and its clinical significance]

The paper reports the results of estimation of plasma protein C (PC), protein S (PS) and antithrombin III (AT III) in 39 normal controls and 70 patients with various chronic liver diseases and concludes that the plasma values of PC, PS and AT III decrease in patients with chronic liver diseases and the decrease seems to be related to the severity of liver diseases.

Color Doppler echocardiography, two-dimensional echocardiography and signs in diagnosis of aortic regurgitation

To assess the diagnostic significance of color Doppler and two-dimensional echocardiography and signs in aortic regurgitation (AR), we studied 48 patients with AR confirmed by color Doppler. On color Doppler, an abnormal diastolic flow originating from the aortic valve was visualized in the left ventricular outflow tract in the 48 cases. The maximal regurgitant jet area was 0.8-23.3 cm2. On two-dimensional echocardiography, the appearance of cardiac chamber and valves did not offer a clue to the existence of AR in 12 patients (25%). On physical examination, diastolic murmur was inaudible in 18 of 45 patients. Peripheral signs of AR were not found in 20 of 45 patients. In slight AR, signs were usually not detected. From the above we are led to conclude that of the patients with AR confirmed by color Doppler echocardiography, only 75% could be detected by two-dimensional echocardiography and about 55% diagnosed by physical examination.

[Preliminary study on crystals of calcium oxalate in 57 Chinese medicines]

This paper reports the results of a study on 57 Chinese medicinal materials, including the distribution of crystals, types of crystal morphology, size or degree of distinctness. Based on the crystal morphology a checking-index diagram has been compiled as foundations for classifying medicinal plants and micro-identifying the tissue powder of medicinal materials.