[A study on relationship between hypertension and polymorphism of ACE gene in male Yi people in Liangshan Yi autonomous prefecture, Sichuan]

OBJECTIVE

To explore relationship between polymorphism of ACE gene and hypertension.

METHODS

A cross-sectional study was conducted and PCR technique was used to analyze gene polymorphism.

RESULTS

Genotypes DD, ID and II of ACE gene accounted for 13.0% and 9.7%, 50.9% and 48.4%, and 36.1% and 41.9%, respectively, in the normotensives and hypertensives. Frequencies of I and D alleles for ACE gene were 61.6% and 66.1%, and 38.4% and 33.9%, respectively, in the normotensives and hypertensives. There was no significant difference in distribution of II, ID and DD genotypes and I/D allele frequencies of ACE gene between the hypertensives and normotensives in male Yi people.

CONCLUSION

Association between polymorphism of ACE gene and hypertension was uncertain.

A mutation in a methionine tRNA gene suppresses the prp2-1 Ts mutation and causes a pre-mRNA splicing defect in Saccharomyces cerevisiae

The PRP2 gene in Saccharomyces cerevisiae encodes an RNA-dependent ATPase that activates spliceosomes for the first transesterification reaction in pre-mRNA splicing. We have identified a mutation in the elongation methionine tRNA gene EMT1 as a dominant, allele-specific suppressor of the temperature-sensitive prp2-1 mutation. The EMT1-201 mutant suppressed prp2-1 by relieving the splicing block at high temperature. Furthermore, EMT1-201 single mutant cells displayed pre-mRNA splicing and cold-sensitive growth defects at 18 degrees. The mutation in EMT1-201 is located in the anticodon, changing CAT to CAG, which presumably allowed EMT1-201 suppressor tRNA to recognize CUG leucine codons instead of AUG methionine codons. Interestingly, the prp2-1 allele contains a point mutation that changes glycine to aspartate, indicating that EMT1-201 does not act by classical missense suppression. Extra copies of the tRNA(Leu)(UAG) gene rescued the cold sensitivity and in vitro splicing defect of EMT1-201. This study provides the first example in which a mutation in a tRNA gene confers a pre-mRNA processing (prp) phenotype.

Metastasis-related genes in prostate cancer

The identification of genes specifically related to the development of metastatic disease in prostate cancer is complicated by tumor cell heterogeneity and the presence of expressed sequences that are not related to metastasis. A system was designed to minimize these complications using differential display-polymerase chain reaction (DD-PCR) together with genetically paired cell lines derived from primary mouse prostate cancer and their associated metastases generated in vivo by the metastatic mouse prostate cancer reconstitution model. Using this system, a number of metastasis-related sequences were identified, including a cDNA that encodes caveolin-1.

[The development of a hemorrhologity observating and measuring instrument]

A new instrument for observing blood cell state and the process of variation on hemorrheology has been developed. There are three ways of shear rate: setting by hand, automatically setting and simulating pulsative state. It can provide different variable flow fields. The shear rate can be set in the range from 0.1 to 1000 s-1. It needs only a little blood. It can be easyly and rapidely operated. it has clear images. The hemorrheology state of blood cells can be directly perceived through thd instrument by eyes. The display and measurement and record of blood cell's hemorrheology state can be finished in real time dynamically and simultaneously.

[Systemic inflammatory response syndrome in critical patients - an analysis of 1,292 cases]

OBJECTIVE

To study the significance of the occurrence and the development of systemic inflammatory response syndrome (SIRS) in critical patients.

METHODS

The clinical data of 1292 patients accepted by our hospital in ten months from October 1995 to July 1996 were analyzed. The patients met at least two of the criteria for SIRS such as fever, hypothermia, tachycardia, tachypnea or abnormal white blood cell count.

RESULTS

1292 (67.7%) of the 1909 patients investigated met two or more of the criteria for SIRS. In the 1292 cases, those who met two, three or four of the criteria were respectively 467 (36.1%), 526 (40.7%) and 299 (23.1%). 149 patients (11.5%) in the 1292 cases died of multiple organ dysfunction syndrome (MODS). In which 33 (7.1%), 57 (10.8%) and 59 (19.7%) respectively in patients with two, three and four of the criteria for SIRS. The proportion of patients suffering from acute respiratory distress syndrome, metabolic function dysfunction, disseminated intravascular coagulation and acute renal failure increased with the increase in the number of SIRS criteria that the patients met and with the increase in the proportion of patients progressing from SIRS to septic shock. The mortality rate of the patients also gradually increased while the patients with SIRS were developing sepsis, severe sepsis and septic shock, but there was no statistical significance (P > 0.05).

CONCLUSION

It is suggested that bacterial infection, severe trauma and acute pancreatitis might cause SIRS and compensatory anti-inflammatory response syndrome might play an important role in the maintenance of internal environment of the body. A comprehensive understanding of SIRS might be of help to the management of critical diseases.

Suppression of caveolin expression induces androgen sensitivity in metastatic androgen-insensitive mouse prostate cancer cells

Although prostate cancer cells are often initially sensitive to androgen ablation, they eventually lose this response and continue to survive, grow and spread in the absence of androgenic steroids. The mechanism(s) that underlie resistance to androgen ablation therapy remain mostly unknown. We have demonstrated that elevated caveolin protein levels are associated with human prostate cancer progression in pathological specimens. Here we show that suppression of caveolin expression by a stably transfected antisense caveolin-1 cDNA vector converted androgen-insensitive metastatic mouse prostate cancer cells to an androgen-sensitive phenotype. Orthotopically grown tumors and low-density cell cultures derived from antisense caveolin clones had increased apoptosis in the absence of androgenic steroids, whereas similarly grown tumors and cells from vector (control) clones and parental cells were not sensitive to androgens. Studies using a representative antisense caveolin clone showed that selection for androgen resistance in vivo correlated with increased caveolin levels, and that adenovirus-mediated caveolin expression blocked androgen sensitivity. Our results identify a new candidate gene for hormone-resistant prostate cancer in man and indicate that androgen insensitivity can be an inherent property of metastatic prostate cancer.

Elevated expression of caveolin is associated with prostate and breast cancer

To identify genes associated with prostate cancer progression, we developed a strategy involving the use of differential display-PCR with a panel of genetically matched primary tumor- and metastasis-derived mouse prostate cancer cell lines. We isolated a cDNA fragment with homology to the mouse caveolin-1 gene. Northern blotting with this fragment revealed increased caveolin expression in metastasis-derived cell lines relative to primary tumor-derived cell lines. Western blotting with a polyclonal caveolin antibody confirmed increased caveolin protein in metastasis-derived mouse cell lines and expression in three of four human prostate cancer cell lines. Immunohistochemical analysis of a human prostate cancer cell line demonstrated a prominent granular pattern of caveolin accumulation. Subsequent analysis of mouse and human prostate specimens revealed minimal caveolin expression in normal epithelium with abundant staining of smooth muscle and endothelium. The frequency of caveolin-positive cells was increased in prostate cancer with markedly increased accumulation of caveolin and a granular staining pattern in lymph node metastatic deposits. In human breast cancer specimens, increased caveolin staining was detected in intraductal and infiltrating ductal carcinoma as well as nodal disease. Caveolin therefore appears to be associated with human prostate cancer progression and is also present in primary and metastatic human breast cancer.

[CYP2D6 and GSTM1 genetic polymorphism and lung cancer susceptibility]

OBJECTIVE

To evaluate the relationship between CYP2D6 and GSTM1 genetic polymorphism and lung cancer susceptibility among Cantonese in China.

METHODS

In a case-control study, PCR was used to identify CYP2D6 and GSTM1 genotypes and restriction enzyme BstNI was used to identify a specific point mutation of CYP2D6.

RESULTS

Between lung cancer patient group and normal control group CYP2D6 genetic polymorphism did not show frequency distribution differences but that of GSTM1 did (58.7% n = 46, 35.7%, n = 70, P < 0.05) OR = 2.56(1.11-2.44).

CONCLUSION

There is no association between CYP2D6 G-A mutation and lung cancer susceptibility, while individuals with GSTM1 -/- genotype are susceptible to lung cancer.

Reduced lysyl oxidase messenger RNA levels in experimental and human prostate cancer

To identify genes associated with prostate cancer progression, we developed a strategy involving the use of differential display PCR and a panel of genetically matched primary tumor- and metastasis-derived mouse prostate cancer cell lines. We analyzed sequences that were differentially stimulated by transforming growth factor-beta1 in primary tumor-versus metastasis-derived cell lines, based on our previous studies indicating that acquisition of differential responses to this growth factor could result in phenotypic traits that facilitate tumor metastasis from specific cell clones within the primary tumor. Using this system, we isolated and sequenced a cDNA fragment that encoded mouse lysyl oxidase (LO) and was induced by transforming growth factor-beta1 in primary tumor but not in metastasis-derived cells. Northern blotting analysis revealed increased LO expression in a panel of primary tumor cell lines but significantly reduced or nondetectable expression in their matched metastatic counterparts. Further in situ hybridization analysis revealed LO expression in normal mouse prostate epithelium but, in most cases, progressive loss of expression in primary prostate cancer and associated metastatic lesions. Importantly, in situ hybridization studies of normal human prostate and prostate malignancies revealed a similar loss of expression during progression to metastasis. The progressive loss of LO expression during prostate cancer progression provides information that may increase our understanding of the mechanisms that underlie this disease. In addition, LO may provide a useful molecular marker and/or establish a novel therapeutic target for prostate cancer.

[A deep regional impedance method measuring the blood distribution in the lung]

A new deep regional impedance method to measure the blood distribution in the lung has been developed. Using a multi-electrode system, the method simultaneously detects impedance information of chest, and back including lung and the thorax, then extracts the impedance information directly from lung with a special data processing approach in order to eliminate thorax effect on the measurement. The salt pool experiment and the preliminary application of measuring the blood distribution in the lung have been made. The results show that the method raises the relative sensitivity and the distinguishability of the blood measurement in the lung, and as a new deep regional impedance measurement method, it has a good prospects of clinical application in the future.

[The development of a multifunction shear flow field generating device]

A new shear flow field generating device has been developed. It can be widely used in the basic research of hemorheology, clinical test and measurement. It has rich functions and can make dynamic measurement of hemorheology parameters. There are three work ways of shear rate: setting by hand, automatically setting and simulating pulsative state. It can provide different variable flow fields. The shear rate can be set in the range from 0.1 to 1000 s-1.

[Antioxidative effect of constituents of herba Epimedii (ESPS)]

Herba Epimedii is a traditional Yang invigorating Chinese herb widely used in clinic. The experimental results have shown that ESPS obviously increases superoxide dismutase(SOD) activity of red cells and liver in aged mice and rats, and increases glutathione peroxidase(GSH-Px) activity of red cells in aged mice. On the other hand, ESPS obviously helps to reduce the content of serum and liver lipoperoxide(LPO) in aged mice and rats, as well as the content of lipofuscin(LF) in cardiac muscle of aged mice. The results suggest that being helpful in increasing SOD and GSH-Px activities and inhibiting the formation of LPO and LF, ESPS may be a good antiageing agent.

[Experimental study on bone formation in a denser coral used for repairing cortical defects in dogs]

The present study was designed to investigate a coral skeleton, Favites, which was originated from the reef builders in Hainan island, as a bone substitute. The coral Favites, like porites, is composed of anagonite (CaCO3), but contains less volume of porosity, higher strength and denser construction than Porites. After implanted into cortical bone defects in mandibles and femurs of dogs, skeleton fragment of coral Favites demonstrated good biocompatibility and biodegradability. A resorption of the implant and a simultaneous apposition of new bone was observed. Coral Favites was totally replaced by newly formed bone after a period of time from 6-8 months. Compared to Porites, Favites has a lower rate of resorption and therefore the defects of host bone are repaired completely without any lost of bone volume. The results showed that coral Favites may be used as a bone substitute for the segmental defects of mandibles.

[Effect of active constituents of Herba Epimedii on hypothalamic monoamine neurotransmitters and other brain functions in aging rats]

The active constituents of Herba Epimedii can raise the hypothalamic monoamine neurotransmitters levels in aging male rats and improve the learning and memory in aging rats and mice. It can also inhibit the activities of AchE both in brain tissues and whole blood in mice.

A novel electric design for electromagnetic stimulation--the Slinky coil

A novel coil design for inductive electromagnetic stimulation of neural cells has been simulated and experimentally tested. This coil improves the focal effect of a magnetic stimulator, and it reduces its inductance, hence the efficiency of the system is improved. The basic structure of the device is derived from the popular "Slinky" toy. The actual device is formed by winding different numbers of loops forming a helical coil on a half torus. The loops are bunched at the axis of the torus. The coil, due to its geometry, generates a unique distribution of eddy currents in nearby tissues which is favorable compared to a solenoid type stimulator. This renders the Slinky coil more selective than conventional coils used for magnetic stimulation. The distribution of eddy currents was analyzed using Matlab, following Faraday's Law of Induction. Improved focality permits the current through the coil to be reduced for the same effect. In addition, the reduced inductance of the Slinky coil decreases the power requirement; thus, the improved efficiency of the system may allow the generation of bursts of pulses, and expand the utilization of the system to possible functional activation of certain neuro-muscular structures when peripheral nerves are stimulated.

Loss of p53 function leads to metastasis in ras+myc-initiated mouse prostate cancer

To study the interactions between dominantly acting oncogenes and tumor suppressor genes we used p53 'knockout' mouse urogenital sinus tissue for retroviral transduction of ras and myc in the mouse prostate reconstitution (MPR) model system. Epithelial hyperplasia was observed in all wild-type p53 MPRs with one small focal cancer and no evidence of metastasis. Prostatic cancer was found in 100% of the heterozygous and homozygous p53 mutant MPRs with metastatic deposits in 95% of the mice. The pattern of metastasis was remarkably similar to that in human prostate cancer with gross metastatic deposits in the lung, lymph nodes, bone and liver of many animals. Progression of carcinomas in the ras+myc-initiated heterozygous p53 mutant MPRs was invariably associated with either complete loss, partial deletion or loss of expression of the wild-type p53 allele. Southern blotting analysis of proviral-cellular DNA junction fragments in primary carcinomas and cell lines derived from metastatic deposits revealed that metastases do not necessarily seed out from the most abundant clone in the primary carcinoma.

Hypotension preferentially induces c-fos immunoreactivity in supraoptic vasopressin neurons

Immunoreactivity to Fos protein (Fos-IR) was detected in rat hypothalamic neurons within 1 h of onset of hemorrhage by withdrawing 4-5 ml of blood, which lowered the arterial blood pressure to 50-70 mm Hg. About 70% of vasopressin (AVP)-containing neurons in the supraoptic nucleus (SON) and 20% in the paraventricular nucleus (PVN) expressed Fos-IR. In contrast, 5% of oxytocin (OXY)-containing neurons in the SON and < 1% in PVN were Fos-IR. Intravenous infusion of the vasodilating agent, nitroprusside, which lowered the blood pressure to levels comparable to that attained by hemorrhage, induced Fos-IR in greater than 65% of AVP-containing neurons in the SON, while relatively few AVP neurons in the PVN were Fos positive. These results suggest that hemorrhage or hypotension preferentially induces c-fos expression in supraoptic AVP-containing neurons.

Synaptic mechanisms in sympathetic preganglionic neurons

Intracellular recordings from sympathetic preganglionic neurons (SPNs) in adult cat and neonatal rat spinal cord slices reveal four types of synaptic potentials, namely, excitatory postsynaptic potentials (EPSPs), inhibitory postsynaptic potentials (IPSPs), and slow EPSPs in both preparations, and a slow IPSP in cat SPNs. Pharmacological studies show that glutamate or a related excitatory amino acid and glycine are the probable mediators of EPSPs and IPSPs. There may be heterogenous mediators of slow EPSPs; substance P, serotonin, norepinephrine, and epinephrine are all probable mediators of slow EPSPs in subpopulations of SPNs. In the case of slow IPSPs, norepinephrine appears to be the likely transmitter. Finally, stimulation of ventral roots elicits a synaptic potential that appears to be caused by glutamate released from afferent fibers in the ventral roots. Our results indicate that a multitude of synaptic mechanisms exist in the rat SPNs by means of which inputs arising from sensory and supraspinal neurons are processed in a timely and orderly manner, thus ensuring highly organized but differentiated outputs to multiple peripheral target cells.

Hypovolemia induces Fos-like immunoreactivity in neurons of the rat supraoptic and paraventricular nuclei

Immunoreactivities to Fos proteins were detected in numerous neurons in the supraoptic, paraventricular and accessory neurosecretory nuclei 1 h following withdrawal of 4-5 cc of blood from the rat femoral arteries. Few or no positive cells were observed in the same nuclei in sham-operated or control animals. It is concluded that hypovolemia induces c-fos expression in hypothalamic neurons known to be associated with blood volume/pressure regulation.