CD3 delta deficiency arrests development of the alpha beta but not the gamma delta T cell lineage

The CD3 complex found associated with the T cell receptor (TCR) is essential for signal transduction following TCR engagement. During T cell development, TCR-mediated signalling promotes the transition from one developmental stage to the next and controls whether a thymocyte undergoes positive or negative selection. The roles of particular CD3 components in these events remain unclear. Indeed, it is unknown whether they have specialized or overlapping roles. However, the multiplicity of CD3 components and their evolutionary conservation suggest that they serve distinct functions. Here the developmental requirement for the CD3 delta chain is analyzed by generating a mouse line specifically lacking this component (delta-/- mice). Strikingly, CD3 delta is shown to be differentially required during development. In particular, CD3 delta is not needed for steps in development mediated by pre-TCR or gamma delta TCR, but is required for further development of thymocytes expressing alpha beta TCR. Absence of CD3 delta specifically blocks the thymic selection processes that mediate the transition from the double-positive to single-positive stages of development.

[Evaluation on ISGP classification of endometrial hyperplasia in clinical application]

To evaluate clinical application of International Society of Gynecologic Pathologists Classification of endometrial hyperplasia 424 patients with endome trial hyperplasia were treated in our hospital from Sept. 1989 to Feb. 1995. Our of these cases, 339 were simple hyperplasia, 28 were complex hyperplasia and 57 atypical hyperplasia. We made an analysis of the cases of complex and atypical hyperplasia in terms of the ISGP classification. The total rate of curettage was 63.5%. The agreement rate for pathologic diagnoses before and after operation was 78%. Under the age of 40, 18 patients had atypical hyperplasia and 15 of them underwent hysterectomy. Eight patients had complex hyperplasia and 3 of them underwent hysterectomy. Above the age of 40, 39 patients had atypical hyperplasia and 30 of them had uterus removed. Twenty patients had complex hyperplasia and 12 of them had uterus removed. These suggest that the ISGP pathologic diagnostic method is good to avoid overdiagnosis and overtreatment. Yet, diagnostic curettage is still the best means in diagnosis before operation.

[The inhibitory effect of hydroprednisolone on tumor necrosis factor in rabbits' temporomandibular joint disturbance syndrome]

In order to study the mechanism of hydroprednisolone for temporomandibular joint disturbance syndrome (TMJDS), 12 white rabbits were injected TNF into the rabbits' right TMJDS for 2 to 3 times, 90,000 u each time, then another drug, 2 mg hydroprednisolone, was injected into these TMJDS again. The rabbits were killed after 8 to 18 days and the TMJDS were examined by microscope. We found the articular tissues only destroyed slightly and sometimes the cartilages were nearly normal. So, the study suggested that hydroprednisolone can reduce the destruction of TNF on rabbit's TMJ obviously. This may be the cause why hydroprednisolone is useful to TMJDS.

Nucleation and polymerization of sickle hemoglobin with Leu beta 88 substituted by Ala

We have measured the solubility, and the rates of homogeneous and heterogeneous nucleation on sickle hemoglobin (HbS beta 6 Glu-->Val) additionally modified by site-directed mutagenesis to possess Ala rather than Leu at beta 88, which forms part of the receptor site for beta 6 Val in the sickle polymer. The solubility of the hemoglobin is increased at all temperatures, and is about 29 g/dl at 25 degrees C. Polymerization kinetics, induced by laser photolysis and observed by light-scattering intensity, showed exponential growth with rates about 300 times slower than experiments done on similar concentrations of HbS. When polymerization is carried out in small volumes, the time of measurable light-scattering signal to reach one-tenth of its final value (denoted as the tenth time) showed stochastic fluctuations, as is seen in pure HbS. Homogeneous nucleation rates were measured by observing distributions of tenth times and these rates were slowed by the mutation by almost 1000-fold relative to pure HbS. The kinetics, including the exponential progress curves and shape of the tenth time distributions, are well described by the double nucleation mechanism for polymerization. Analysis of the homogeneous nucleation rates leads to the surprising conclusion that the mutation has scarcely changed the energy of the intermolecular contacts despite the increase in solubility of the double mutant. This conclusion is supported by the stereochemistry of the modified contact site, in which the amount of exposed hydrophobic surface appears to be unchanged by the mutation. The increased solubility must therefore result from decreased motional freedom of molecules within the polymer, which could arise from tighter packing into the enlarged receptor pocket. This points up the ability of kinetic analysis to reveal important thermodynamic properties of assembly, and underlines the importance of the vibrational degrees of freedom in setting the final equilibrium constant. Chemical modifications to restrict vibrations and enhance the cost of polymerization may prove useful in constructing compounds to act as inhibitors of sickle cell gelation.

Pathogenesis of Acanthamoeba keratitis: carbohydrate-mediated host-parasite interactions

Acanthamoeba keratitis is a sight-threatening corneal infection. In a recent study, the saccharide mannose has been shown to inhibit the binding of Acanthamoeba organisms to the epithelium of the cornea (L. D. Morton, G. L. McLaughlin, and H. E. Whiteley, Infect. Immun. 59:3819-3822, 1991). In an attempt to determine the molecular mechanism by which acanthamoebae adhere to the surface of the cornea, the present study was designed to determine whether Acanthamoeba castellanii derived from an infected human cornea (i) binds to mannose-containing glycoproteins (mannose-GPs) of corneal epithelium and (ii) expresses one or more mannose-binding proteins. Mannose-GPs of primary cell cultures of rabbit corneal epithelium were isolated by using three different agarose-conjugated, mannose-specific lectins. By electrophoresis blot-overlay assays, 35S-labeled acanthamoebae were shown to bind to mannose-GPs of corneal epithelium and to a neoglycoprotein, mannose-bovine serum albumin (mannose-BSA). 35S-labeled acanthamoebae also bound to microtiter wells coated with mannose-BSA in a concentration-dependent manner. The binding of amoebae to mannose-GPs was blocked by free methyl-alpha-D-mannopyranoside. The parasites did not bind to galactose-BSA or to many other proteins lacking mannose residues. A membrane-associated mannose-binding protein (136 kDa) of A. castellanii was isolated by affinity chromatography of detergent extracts of unlabeled parasites and of cell surface biotin-labeled parasites on a p-aminophenyl alpha-D-mannopyranoside-agarose column. The affinity-purified protein of the amoeba was shown to bind specifically to mannose-BSA. In summary, a mannose-binding protein is present on the surface membranes of Acanthamoeba, and corneal epithelial cells express Acanthamoeba-reactive GPs. One of the mechanisms of Acanthamoeba adhesion to the corneal surface may involve interactions between the mannose-binding protein of Acanthamoeba and mannose-GPs on the surface of corneal epithelium.

Electrochemical and histomorphometric evaluation of the TiNiCu shape memory alloy

By means of electrochemical and quantitative histomorphometric methods, the corrosion resistance and tissue biocompatibility of Ti50Ni50 and Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) were investigated. It is discovered that the repassivation potential of Ti50Ni50-xCux (x = 2, 4, 6, 8) alloys is about 200 mV higher than that of Ti50Ni50 alloy. Namely, the addition of Cu raises the repassivation potential of TiNi shape memory alloys and improves their corrosion resistance. Pitting potentials of Ti50Ni50 and Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) alloys increase with solution pH value, but the repassivation potentials keep constant. The adding of Cu has no obvious influence on pitting potential (Epit) of TiNi alloys, meanwhile, the corrosion potential and corrosion rate of Ti50Ni50-xCux (x = 1, 2, 4, 6, 8) alloys are irrelevant to its Cu content and the values are almost the same as those of TiNi alloys. The connective tissue layer covering the plates is statistically significantly thicker for Ti50Ni42Cu8 plates (p < 0.05) than that of Ti50Ni50, Ti50Ni48Cu2, Ti50Ni44Cu6 plates after one month. The numbers of connective tissue cells, polynucleated cells, macrophages and round cells are higher for Ti50Ni42Cu8 plates than those of the other three types of plates, but no statistically significant differences are detected. There are no significant differences on tissue reaction parameters after two and three months among four alloys. After one, two and three months implantation, no corrosion is observed on the plates surfaces. A preliminary conclusion can be drawn that Ti50Ni50-xCux (x = 2, 6, 8) shape memory alloys have good biocompatibility.

Homogeneous nucleation in sickle hemoglobin: stochastic measurements with a parallel method

The homogeneous nucleation rate for sickle hemoglobin polymerization has been measured for concentrations from 3.9 to 4.9 mM and temperatures from 13 degrees C to 35 degrees C by observing the stochastic fluctuations of the time to complete 10% of the reaction after photolysis of the carboxy derivative. To allow efficient data collection, a mesh was used to divide the photolysis beam into an array of smaller beams, which allowed parallel observation of about 100 different regions. Nucleation rates measured here are consistent with more restricted previously published data and, when combined with directly measured monomer addition rates, are consistent with previous analysis of progress curves. By describing these rates with equilibrium nucleation theory, the concentration of nuclei and hence their stability can be ascertained. Consequently, the chemical potential by which a monomer is attached to the polymer is determined. This attachment energy ranges from -6.6 to -8.0 kcal/mol between 15 degrees C and 35 degrees C. The enthalpic part of that chemical potential is found to be equal to the enthalpy determined by solubility measurements, as expected from thermodynamic considerations. The entropic portion of the contact chemical potential contributes from -21.4 to -8.7 kcal/mol. The vibrational chemical potential of monomers in the polymer ranges from -25.7 to -27.4 kcal/mol over the same temperatures.

Comparison of continuous step-and-shoot versus step-and-shoot acquisition SPECT

This study compared the quality of SPECT images obtained with step-and-shoot mode (SSM) and continuous step-and-shoot mode (CSSM).

METHODS

Computer simulations of SSM and CSSM were performed with a two-dimensional Shepp-Logan head phantom and a high-resolution parallel-hole collimator. The effects of noise and photon attenuation were examined.

RESULTS

Without noise and without attenuation, small structures in reconstructed images obtained using fast CSSM (less than 4 sec per view plus the moving time from one view to the next) were slightly blurred and rotated in the opposite direction of detector motion. With both noise and attenuation, these artifacts were not visible, and the image quality obtained from CSSM, especially from fast CSSM, was improved as compared to that resulting from the corresponding SSM due to the increasing number of counts. The improvement of image quality became less significant with increasing acquisition time and in the presence of attenuation.

CONCLUSION

For fast SPECT, CSSM provided better image quality than the corresponding SSM, especially when attenuation effects were not present. For relatively long time SPECT without attenuation compensation that is typical for clinical studies, the image quality of CSSM was similar to that of SSM.

Phantom evaluation of simultaneous thallium-201/technetium-99m aquisition in single-photon emission tomography

This study investigated downscatter effects in cardiac single-photon emission tomographic studies with simultaneous thallium-201/technetium-99m acquisition, and evaluated a previously proposed subtraction technique for downscatter compensation. Ten studies were carried out with different defect sizes and locations and varying activity distributions using four energy windows: 70+/-10% keV, 140+/-10% keV, 100+/-10% KeV, and 103+/-16% keV. The subtraction technique used the 100- or 103-keV data to remove scattered 99mTc counts from the 70-keV data. The size and contrast of infarcts in the dual-isotope 70-keV image were artificially decreased compared to those in the 140-keV image, caused by scattered 99mTc counts that were comparable to the primary 201Tl counts in the 70-keV window. The subtraction technique produced larger defects and more heterogeneous activity in the myocardial wall in dual-isotope 70-keV images compared to the corresponding 201Tl-only images. These artifacts were caused by the markedly different spatial distributions of scattered 99mTc counts in the 100-keV (or 103-keV) window as compared with the 70-keV window. It is concluded that scattered 99mTc photons may cause overestimation of ischemia and myocardial viability in simultaneous dual-isotope patient studies. The proposed subtraction technique was inaccurate and produced image artifacts. Adequate downscatter compensation methods must be developed before applying simultaneous 201Tl/99mTc acquisition in clinical practice.

The role of betagamma and alphagamma complexes in the assembly of human fibrinogen

The role of alphagamma and betagamma dimers as intermediates in the assembly of fibrinogen was examined in cell fusion experiments using stably transfected baby hamster kidney cell lines expressing one or combinations of fibrinogen chains. Fibrinogen was readily formed and secreted into the culture media when cells co-expressing beta and gamma chains and generating betagamma complexes were fused with cells expressing only the alpha chain. Likewise, when cells co-expressing alpha and gamma chains and generating alphagamma complexes were fused with cells expressing only the beta chain, fibrinogen was also formed and secreted. The relative amounts of alphagamma or betagamma intermediates observed during fibrinogen biosynthesis were determined by the levels of the component chains; i.e. when the beta chain was limiting, the alphagamma dimer was the predominant intermediate; likewise, when the alpha chain was limiting, the betagamma complex was the predominant intermediate. The incorporation of preformed alphagamma and betagamma complexes into secreted fibrinogen did not require concurrent protein synthesis, as shown by experiments employing cycloheximide. These data strongly support the role of alphagamma and betagamma complexes as functional intermediates in the assembly of fibrinogen.

TRAF6 is a signal transducer for interleukin-1

Many cytokines signal through different cell-surface receptors to activate the transcription factor NF-kappaB. Members of the TRAF protein family have been implicated in the activation of NF-kappaB by the tumour-necrosis factor (TNF)-receptor superfamily. Here we report the identification of a new TRAF family member, designated TRAF6. When overexpressed in human 293 cells, TRAF6 activates NF-kappaB. A dominant-negative mutant of TRAF6 inhibits NF-kappaB activation signalled by interleukin-1 (IL-1) but not by TNF. IL-1 treatment of 293 cells induces the association of TRAF6 with IRAK, a serine/threonine kinase that is rapidly recruited to the IL-1 receptor after IL-1 induction. These findings indicate that TRAF proteins may function as signal transducers for distinct receptor families and that TRAF6 participates in IL-1 signalling.

Optimal number of views in 360 degrees SPECT imaging

This study examined SPECT-reconstructed image quality as a function of the number of views, and determined the minimum number of views necessary to remove aliasing artifacts in 360 degrees SPECT.

METHODS

Computer simulation was performed using a two-dimensional Shepp-Logan head phantom and a high-resolution parallel-beam collimator with and without photon attenuation.

RESULTS

In 360 degrees SPECT, aliasing artifacts were reduced by changing the number of views from an even number 16 to its neighboring odd numbers 15 or 17, from 32 to 31 or 33 and from 64 to 63 or 65. Image quality of 15 or 17 views, 31 or 33 views and 63 or 65 views was similar to that of 32, 64 and 128 views, respectively.

CONCLUSION

Replacing an even number of views by its neighboring odd numbers in 360 degrees SPECT significantly decreased aliasing artifacts. Thirty-one or 33 views are sufficient to remove most of the aliasing artifacts in 360 degrees SPECT with a matrix of 64 x 64 pixels. This method can be applied to fast 360 degrees SPECT since fewer views are used.

A one-hand operation gun for transrectal prostate biopsy

OBJECTIVE

To develop a new automatic biopsy device (ABD) that enables a radiologist to obtain multiple samples with one hand and free the other hand to handle the ultrasonic scanner for continuous monitoring.

MATERIALS AND METHODS

The new ABD developed by us in April 1994 enabled a radiologist to complete all the biopsy procedures including loading and reloading the spring system, firing the device, emptying the specimen, selecting the depth of needle advancement, and multiple sampling, simply by pressing 3 buttons in turn with his/her right thumb. Using this new ABD, transrectal prostate biopsy under the guidance of transrectal ultrasonic imaging was performed in 60 consecutive cases of prostate diseases. Each biopsy procedure was completed by a single radiologist, who was able to obtain multiple specimens with one biopsy needle, using only one hand and freeing the other hand for the manipulation of the ultrasonic scanner for guidance.

RESULTS

A total of 265 satisfactory core tissue specimens of 285 needle passes (93%) were obtained from the 60 patients. Definite pathologic diagnoses were made for all the 60 patients (100%). No serious biopsy-related complications were observed. The main complications were hematuria in 24 of 60 (40%) patients and fever in 5 (8.3%).

CONCLUSION

On the basis of our experience with the 60 patients, this new ABD can be operated smoothly and effectively with the right hand, while the left hand is freed to handle the ultrasonic transducer for continuous monitoring.

Vascular hypertrophy and albumin permeability in a rat model combining hypertension and diabetes mellitus. Effects of calcium antagonism, angiotensin converting enzyme inhibition, and angiotensin II-AT1-receptor blockade

The aim of this study was to compare the effects of angiotensin converting enzyme (ACE) inhibition, angiotensin II (AII) AT1-receptor blockade, and dihydropyridine calcium antagonism on hypertrophy and on vascular albumin permeability in kidney, heart, and mesenteric artery in a model combining genetic hypertension and diabetes mellitus. Diabetes mellitus was induced by streptozotocin in 8-week-old spontaneously hypertensive rats. The animals were randomized to receive no treatment, the angiotensin converting enzyme inhibitor ramipril, the AII AT1-receptor blocker valsartan, or the dihydropyridine calcium antagonist lacidipine for 3 weeks. Vascular albumin permeability was measured as the tissue content of intravenously injected Evans blue dye (EB) in kidney, heart, and mesenteric artery and the tissue/plasma EB ratio was calculated. Systolic blood pressure was reduced by all three antihypertensive regimens. Glycemic control was similar in all diabetic groups. Kidney hypertrophy was not affected by any of the antihypertensive drugs. Hypertrophy of the mesenteric artery was enhanced by lacidipine but was not affected by ramipril or valsartan. Relative heart weight was also increased by lacidipine. Vascular albumin permeability, expressed as EB content in micrograms/gram dry weight or as tissue/plasma EB ratio, was higher in the kidneys of lacidipine-treated rats than in any other group of diabetic rats. There was a positive correlation between kidney weight/body weight and kidney/plasma EB ratio in the diabetic rats. These findings indicate that the dihydropyridine calcium antagonist lacidipine is associated with an unfavorable effect on vascular hypertrophy and on vascular albumin permeability in the kidneys in rats with hypertension and diabetes mellitus. Furthermore, there seems to be a coupling in the diabetic kidney between hypertrophy and increased vascular albumin permeability.

[The value of CA125 and LDH assays in assisting diagnosis of epithelial ovarian carcinoma]

40 first-treated cases of epithelial ovarian cancer, 13 cases of cervical cancer, 13 cases of corpus cancer and 50 cases of benign tumor were included in this study from Jan. 1991 through May 1992 to evaluate the significance of the blood CA125, LDH, CR and SA levels in assisting diagnosis of epithelical ovarian cancer. The CA125 levels of the 40 canses of ovarian cancer were higher than those of cervical cancer and corpus cancer (P < 0.05); the SS, PLR and AC of CA125 in ovarian cancer were higher than those of LDH, SA and CR (P < 0.05); the SS of CA125 in ovarian cancer was higher than that of LDH isoenzyme (P < 0.05). The results show that CA125 may be the best tumor marker in assisting ovarian cancer; CA125 is more informative than LDH, CR and SA; when CA125 is used incombination with other tumor markers, SS, SP, NPV and PPV can be greatly raised.

[Persistent and recurrent gynecologic malignant tumor treated within one year: analysis of 1,753 cases from 61 hospitals in China]

OBJECTIVE

To analyze the causes of persistent and recurrent gynecologic malignant tumors treated within 1 year.

METHODS

20,974 cases of gynecologic malignant tumors from 61 hospitals in 24 provinces admitted between 1983-1993 were collected. Out of the total, 1753 cases treated within 1 year with tumor persistence, recurrence or death were retrospectively analysed.

RESULTS

The ovarian carcinoma and vaginal cancer had the highest rates of tumor persistence, recurrence or death. Among the 1587 cases of tumor persistence or recurrence, pathological grading were not performed in 56.52% of the cases. For surgical treatment, inappropriate operation were done in 81.68% (767/939) of the ovarian carcinoma, 64.38% (103/160) of the cervical carcinoma, and 70.08% (89/127) of the endometrial cancer. 55.47% (532/959) of ovarian cancer and 38.31% (59/154) of choriocarcinoma and malignant mole had insufficient chemotherapy. For cervical cancer, 54.90% (235/396) of the cases did not receive enough doses of radiotherapy.

CONCLUSION

Accurate staging and standardized therapy are important for improving 1 year survival rate in malignant gynecologic tumors.

The beta 1 sodium channel subunit modifies the interactions of neurotoxins and local anesthetics with the rat brain IIA alpha sodium channel in isolated membranes but not in intact cells

Mammalian brain sodium channels consist of an alpha subunit and two smaller beta subunits. The role of the beta 1 subunit in modulating ligand interactions at these channels was examined using a cell line stably expressing human beta1 and rat brain IIA alpha subunits. Coexpression of the beta 1 subunit had no effect on the potencies of sodium channel blockers in inhibiting whole cell [3H]batrachotoxinin A benzoate ([3H]BTX) binding or veratridine-stimulated [14C]guanidinium influx. Coexpression of the beta 1 subunit also had no effect on the potencies of alpha scorpion toxin, brevetoxin, or RU 39568 in stimulating [14C]guanidinium influx. By contrast, coexpression of the beta 1 subunit had dramatic effects on ligand interactions in isolated membranes. In isolated membranes of cells expressing only the alpha subunit, the neurotoxins had no stimulatory effect on [3H]BTX binding and the potencies of local anesthetic-like channel inhibitors were 10-100-fold lower than those at native sodium channels. Whereas in membranes of cells coexpressing the beta 1 subunit, the neurotoxins increased [3H]BTX binding 30-fold and the potencies of the sodium channel inhibitors closely matched those found at native sodium channels. These findings indicate that the beta 1 subunit is not required for the binding of sodium channel activators or inhibitors but rather, that the beta 1 subunit may stabilize the alpha subunit in a functional conformation thereby allowing detection of these interactions in disrupted membranes.

A perfume odour-sensing system using an array of piezoelectric crystal sensors with plasticized PVC coatings

Using PVC polymer as membrane matrix and di-n-octylphenyl phosphate (DOPP) as plasticizer, a piezoelectric crystal sensor (PCS) array with 12 adsorptive materials selected from 68 compounds by cluster analysis has been constructed as a perfume odour-sensing system. The frequency shift data obtained from the sensor array responding to four commercial perfume odours are first autoscaled and then treated by principal component analysis. The experimental results show that the plasticized PVC membrane PCS array provides improved performance of pattern recognition compared with the single adsorptive coating PCS array. The frequency shift response characteristics of these sensors have been investigated experimentally. The proposed sensor array has also been applied to the classification of commercial spirituous liquor, wine and soft drink samples, as well as aliphatic alcohol homologues and isomers.

[A study of intraarticular irrigation-injection therapy of temporomandibular joint and its mechanism]

According to the research that there were some immune and inflammatory substances in the synovial fluid of temporomandibular joint disturbance syndrome (TMJDS), we improved the traditional intraarticular injection and developed an intraarticular irrigation-injection therapy to treat 43 cases of TMJDS and got a good result. The controls include two groups, the simple rinsing and the traditional injection. Statistical analysis showed a highly significant difference in the effects between test and control groups. In order to study the mechanism of the therapy, the tumor necrosis factor (TNF) in synovial fluid of 8 cases were assessed. It was found that the concentration of TNF was reduced markedly after treatment. We think that the new therapy is effectable for TMJDS and could be used widely.