Sublingual capnometry for diagnosis and quantitation of circulatory shock

We investigated sublingual tissue PCO2 during hemorrhagic and septic shock. Hemorrhagic shock was induced in 10 rats. Sublingual PCO2 increased from 45 to 125 mm Hg and arterial pressure declined from 138 to 49 mm Hg, end-tidal PCO2 decreased from 35 to 13 mm Hg, and cardiac index fell from 290 to 77 ml/min/kg. Arterial blood lactate increased from 0.9 to 15.8 mmol/L. Gastric PCO2 was measured in five animals and it increased from 46 to 87 mm Hg. No significant changes were observed in eight "sham" bled animals including the five animals in which gastric PCO2 was measured. Highly significant linear correlations (p < 0.001) between sublingual PCO2 and gastric PCO2 (r = 0.71), cardiac index (r = -0.74), and arterial lactate (r = 0.59) were documented. We subsequently investigated sublingual PCO2 in five animals in which sepsis was induced by intravenous infusion of live Staphylococcus aureus. Like hemorrhagic shock, highly significant linear correlations were observed between end-tidal PCO2 and cardiac index and between sublingual PCO2 and arterial blood lactate. Sublingual PCO2 promises to serve as a technically simple, noninvasive, and rapid response quantitator of severity of circulatory shock states.

The structure and function of A1 and A2B adenosine receptors

Of the four G protein coupled adenosine receptor (AR) subtypes, the A1 is best suited for studies of reconstitution with G proteins. Recombinant A1 receptors extended with hexahistidine and FLAG have been purified to near homogeneity. In reconstitution assays using pure recombinant G protein subunits, the composition of the gamma subunit influences coupling to purified A1ARs. The least well characterized AR is the A2B. New data indicate that A(2B)ARs can trigger the degranulation of canine and human mast cell lines. Recombinant human A(2B)ARs are blocked by the anti-asthma drugs theophylline and enprofylline at concentrations that are used therapeutically to treat asthma. Although A(2B)ARs have long been known to stimulate adenylyl cyclase, they also can activate phospholipase C and mobilize Ca2+ by signaling through Gq/11. There is great potential for new therapies based on compounds that selectively target individual AR subtypes.

Studies in a modified auxiliary abdominal rat heart transplantation model: preservation with colloid-free University of Wisconsin solution

BACKGROUND

Current clinical heart preservation is still limited to 6 hours. A suitable heart transplantation model to rapidly screen the effectiveness of new solutions is essential. This study examines a new screening test-a modification of the conventional abdominal rat heart transplantation model that overcomes its serious limitation of lack of quantitative evaluation of function.

METHODS

Rat hearts, with an externalized intraventricular balloon-tipped catheter, were transplanted immediately (controls) or flushed and stored in colloid-free University of Wisconsin solution in ice for 6, 9, or 12 hours before transplantation. One and 7 days later this catheter was connected to a pressure transducer and a calibrated syringe. Heart rate, maximum developed pressure, and maximum rate of left ventricular pressure rise were determined. Grafts were prepared for histologic study on day 7.

RESULTS

All preserved hearts commenced beating within 2 minutes (controls beat within 20 seconds). On day 1 the heart rate and chamber stiffness (deltaP/deltat) were similar in all groups. The 9- and 12-hour-preserved hearts had significantly (p < 0.05) diminished developed pressure and contractility. On day 7 contractility and developed pressure improved in 9- and 12-hour-preserved grafts. There was extensive muscular atrophy and necrosis, with extensive cellular infiltrate in the 9- and 12-hour-preserved grafts; other grafts showed no damage.

CONCLUSION

This quantitative model provides an ischemia-related gradation of function and greater discrimination than conventional methods. It has refuted previous studies suggesting effective preservation for 20 hours and demonstrated that functional testing is essential in evaluating preservation regimens.

[An experimental research of recombinant human epidermal growth factor on corneal wound healing]

OBJECTIVE

To investigate the effects of recombinant human epidermal growth factor (rhEGF) eye drops on corneal wound healing.

METHODS

Twenty-four white rabbits were randomly divided into 4 groups, 6 rabbits 12 eyes each. Anterior keratectomy of 8 mm in diameter and 1/3 cornea in thickness was performed on each eye. Each of the following concentrations of rhEGF: 1, 10, 100 microg/ml eye drops or normal saline (control) was applied four times daily for a week respectively for one group. The wound area was determined by computer imaging analysis.

RESULTS

The mean epithelial healing rate of rhEGF 1, 10, 100 microg/ml groups was 9.31, 9.96, 9.31 mm(2)/day respectively, significantly greater than 8.11 mm(2)/day of the control group. The action of rhEGF of 10 microg/ml was somewhat better than that of 1 or 100 microg/ml, and no significant difference was noticed among the three rhEGF groups. Moderate inflammation and corneal neovascularization were induced in the rhEGF 100 microg/ml treated group.

CONCLUSION

rhEGF 1 - 10 microg/ml can accelerate corneal wound healing in the rabbit with no adverse side-effects. It may be used to treat serious corneal trauma and ulcer clinically.

Isolation of two functional retinoid X receptor subtypes from the Ixodid tick, Amblyomma americanum (L.)

Retinoid X receptors (RXR) play a central role in a variety of nuclear signaling pathways in both vertebrates and invertebrates. Vertebrate RXRs are encoded by a multigene family whereas the insect RXR homologue, ultraspiracle (USP), is encoded by a single gene. To determine if acarines possess an RXR homologue similar to insect USPs, we isolated cDNAs encoding two distinct RXR genes, AamRXR1 and AamRXR2, from the ixodid tick, Amblyomma americanum (L.). The DNA binding domains share 95 and 87% identity, respectively, with DNA binding domains from insect USP and vertebrate RXR proteins. However, the ligand binding domains of the AamRXRs are more similar to vertebrate RXRs than to insect USP ligand binding domains (approximately 71 vs approximately 52%). Northern blot and RT-PCR analysis reveal both unique and overlapping patterns of AamRXR1 and AamRXR2 expression. Transactivation analysis show that both AamRXRs encode proteins which can form functional ecdysteroid receptors but are unlikely to bind retinoic acids.

Persistent antibody responses but declining cytotoxic T-lymphocyte responses to multiple human immunodeficiency virus type 1 antigens in a long-term nonprogressing individual with a defective p17 proviral sequence and no detectable viral RNA expression

Long-term nonprogressor AD-18 has been infected with human immunodeficiency virus type 1 (HIV-1) for at least 16 years. During the past 5 years, he has had undetectable levels of plasma viremia, and HIV-1 cannot be isolated from him. Sequencing of proviral DNA indicates that the only HIV-1 sequences that can be identified in AD-18 have gross defects in the p17-encoding regions of the gag gene (Y. Huang, L. Zhang, and D. D. Ho, Virology 240:36-49, 1998). However, AD-18 has strong, sustained antibody responses to several HIV-1 antigens, including p17. Cytotoxic T-lymphocyte responses to Env and Gag antigens have gradually diminished over the past 4 years, at a time when the titers of antibodies to the same proteins have remained stable. We discuss what these observations might mean for the generation and maintenance of immunological memory.

Quantitation of HIV-1-specific cytotoxic T lymphocytes and plasma load of viral RNA

Although cytotoxic T lymphocytes (CTLs) are thought to be involved in the control of human immunodeficiency virus-type 1 (HIV-1) infection, it has not been possible to demonstrate a direct relation between CTL activity and plasma RNA viral load. Human leukocyte antigen-peptide tetrameric complexes offer a specific means to directly quantitate circulating CTLs ex vivo. With the use of the tetrameric complexes, a significant inverse correlation was observed between HIV-specific CTL frequency and plasma RNA viral load. In contrast, no significant association was detected between the clearance rate of productively infected cells and frequency of HIV-specific CTLs. These data are consistent with a significant role for HIV-specific CTLs in the control of HIV infection and suggest a considerable cytopathic effect of the virus in vivo.

Determination of the sites of posttranslational modifications in the charge isomers of bovine myelin basic protein by capillary electrophoresis-mass spectroscopy

The posttranslational modifications in each of the 18.5 kDa bovine myelin basic protein charge isomers C-1 to C-6 have been determined by the use of capillary electrophoresis-mass spectroscopy. The pattern of modifications is viewed as being unique to each charge isomer and is thought to reflect a specific placement and function for each isomer in the myelin membrane. Several of the sites of posttranslational phosphorylation were found to differ from a number of the reported sites that were phosphorylated in vitro by various kinases. These differences suggest that an extremely cautious approach be taken in identifying in vivo posttranslationally modified amino acid residues from residues that have been modified in vitro by various kinases. We have identified the following posttranslationally phosphorylated and deamidated, modified sites in the bovine MBP components C1-C6. C1 has no modification; C2 represents a deamidation of Gln 146; in C3, Thr 97 and Ser 164 are phosphorylated; in C4, Ser 54, Thr 97, and Ser 160 are phosphorylated; in C5 Ser 7, Ser 54, Thr 97, and Ser 164 are phosphorylated; and in C6, Ser 7, Ser 54, Thr 97, Ser 160, and Ser 164 are phosphorylated.

Expression of p16 induces transcriptional downregulation of the RB gene

The RB and p16(INK4A) tumor suppressor genes function in the same pathway of cell cycle control. Previous evidence indicates that the p16(INK4A) gene is transcriptionally repressed by the RB gene product, pRB. In this study using human ovarian cancer cell lines, we found that RB protein and mRNA were expressed at higher levels in cell lines lacking p16 than in those with normal p16. Since this suggests a potential role of p16 in regulating the cellular level of pRB, we studied the effect of wild-type p16(INK4A) on expression of the RB gene. Introduction of p16(INK4A), carried by an adenovirus vector, into p16-negative cell lines dramatically decreased expression of RB protein and mRNA. Nuclei run-off assays demonstrated that p16 expression induced transcriptional downregulation of the RB gene. These results indicate that expression of RB is inversely regulated by p16. The findings reveal a new dimension of pRB-p16 interaction and should have implications for p16(INK4A)-mediated gene therapy.

Surface micromachined capacitive ultrasonic transducers

The current state of novel technology, surface microfabricated ultrasonic transducers, is reported. Experiments demonstrating both air and water transmission are presented. Air-coupled longitudinal wave transmission through aluminum is demonstrated, implying a 110 dB dynamic range for transducers at 2.3 MHz in air. Water transmission experiments from 1 to 20 MHz are performed, with a measured 60 dB SNR at 3 MHz. A theoretical model is proposed that agrees well with observed transducer behavior. Most significantly, the model is used to demonstrate that microfabricated ultrasonic transducers constitute an attractive alternative to piezoelectric transducers in many applications.

[Treatment of man's voice disorder (gynecophonus) by microcomputer]

Using the microcomputer, as a voice training method in the treatment of gynecophonus was presented in 2 cases, to further study the treatment of this kind of voice disorder. Satisfactory results were gained. Meanwhile, the method and effect were also discussed.

[Accumulation sites of kanamycin in the organ of Corti by microautoradiography]

The accumulation sites of the 3H-labelled kanamycin in the organ of Corti were observed with electron microscope. The results showed that the accumulation of kanamycin was mainly in the mitochondria, cell membrane and stereocilia of the hair cells. The possible mechanism of the kanamycin accumulation in the mitochondria is their similarity with bacteria in the protein synthesis, i.e. the way that kanamycin might inhibit the protein synthesis in the mitochondria is similar to that of bacteria. The kanamycin accumulation in the cell membrane may indicate the entrance of kanamycin into the hair cells. The kanamycin deposition in the stereocilia was most likely related to its high chemical affinity with glycocalyx.

Inosine binds to A3 adenosine receptors and stimulates mast cell degranulation

We investigated the mechanism by which inosine, a metabolite of adenosine that accumulates to > 1 mM levels in ischemic tissues, triggers mast cell degranulation. Inosine was found to do the following: (a) compete for [125I]N6-aminobenzyladenosine binding to recombinant rat A3 adenosine receptors (A3AR) with an IC50 of 25+/-6 microM; (b) not bind to A1 or A2A ARs; (c) bind to newly identified A3ARs in guinea pig lung (IC50 = 15+/-4 microM); (d) lower cyclic AMP in HEK-293 cells expressing rat A3ARs (ED50 = 12+/-5 microM); (e) stimulate RBL-2H3 rat mast-like cell degranulation (ED50 = 2.3+/-0.9 microM); and (f) cause mast cell-dependent constriction of hamster cheek pouch arterioles that is attenuated by A3AR blockade. Inosine differs from adenosine in not activating A2AARs that dilate vascular smooth muscle and inhibit mast cell degranulation. The A3 selectivity of inosine may explain why it elicits a monophasic arteriolar constrictor response distinct from the multiphasic dilator/constrictor response to adenosine. Nucleoside accumulation and an increase in the ratio of inosine to adenosine may provide a physiologic stimulus for mast cell degranulation in ischemic or inflamed tissues.

Canine mast cell adenosine receptors: cloning and expression of the A3 receptor and evidence that degranulation is mediated by the A2B receptor

We cloned and characterized the canine A3 adenosine receptor (AR) and examined AR-induced degranulation of the BR line of canine mastocytoma cells. Canine A3AR transcript is found predominantly in spleen, lung, liver, and testes and encodes a 314-amino acid heptahelical receptor. 125I-N6-Aminobenzyladenosine binds to two affinity states of canine A3AR with KD values of 0.7 +/- 0.1 and 16 +/- 0.8 nM, reflecting G protein-coupled and -uncoupled receptors, respectively. Xanthine antagonists bind with similar affinities to human, canine, and rabbit receptors but with 80-400-fold lower affinities to rat A3AR. Although canine BR mastocytoma cells contain A1AR, A2BAR, and A3AR, degranulation seems to be mediated primarily by A2BARs stimulated by the nonselective agonist 5'-N-ethylcarboxamidoadenosine (NECA) but not by the A3-selective agonist N6-(3-iodobenzyl)adenosine-5'-N-methylcarboxamide. NECA-stimulated degranulation is not prevented by pertussis toxin and is blocked by enprofylline (Ki = 7 microM), an antiasthmatic xanthine with low affinity (Ki > 100 microM) for A1AR, A2AAR, and A3AR. NECA increases canine mastocytoma cell cAMP, Ca2+, and inositol trisphosphate levels; these responses are antagonized half-maximally by 7-15 microM enprofylline. The results suggest that (i) the cloned canine A3AR is structurally and pharmacologically more similar to human than to rat A3AR; (ii) the A2BAR, and not the A1AR or A3AR, is principally responsible for adenosine-mediated degranulation of canine BR mastocytoma cells; and (iii) the BR cell A2BAR couples to both Ca2+ mobilization and cAMP accumulation. Although A2B receptors play a major role in the regulation of BR mast cell degranulation, multiple AR subtypes and G proteins may influence mast cell functions.

[Interleukin-6 and tumor necrosis factor-alpha in middle ear effusions]

Using enzyme-linked immunosorbant assay (ELISA), we measured levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in middle ear effusions (MEE) from patients with secretory otitis media (SOM) undergoing auripuncture to study the role of cytokines in the pathogenesis of the disease. Significant levels of IL-6 (> 62.5 ng/L) were found in 19 (86.36%) of 22 MEEs and those of TNF-alpha (> 37.5 ng/L) in 19 (70.37%) of 27 MEEs. The mean (+/- s) levels of IL-6 and TNF-alpha were 507.68 +/- 813.11 ng/L and 186.86 +/- 166.93 ng/L, respectively. It revealed that the shorter the course, the higher the concentration of IL-6 in MEE: the longer the course, the higher the concentration of TNF-alpha in MEE. These findings suggested that during the early stages of SOM, IL-6 might participate in the defensive reaction of organism, while TNF-alpha might be closely related to the persistence of SOM, resulting in an excessive inflammatory reaction with a potential for pathological changes. It is concluded that the immunological mechanisms probably play a significant role in the pathogenesis of SOM.

[Analysis of risk factors for infant deaths in urban and rural areas of Shandong Province]

Data of infant deaths in 1984 and 1994 were collected from the disease surveillance system in Shandong Province and 13 risk factors contributing infant death were analyzed with unconditional logistic regression to reveal their change in urban and rural areas in recent ten years. Results showed that risk factors for infant death in urban areas were birth weight, mother's age of childbirth, length of gestation and maternal health status, with comprehensive population attributable risk proportions (PARP) of 92.24 and 93.81 percent in 1984 and 1994, respectively. In addition to the risk factors mentioned above in urban areas, infant death in rural areas was also affected by ways of delivery and unhealthy events during pregnancy, with a comprehensive PARP of 98.07 percent in 1994. Risks for infant death delivered by family midwives reduced greatly in recent ten years, with an odd ratio (OR) of 4.145 in 1984, but it could not be entered a multivariate regression model in 1994.

The long-term effect of captopril treatment on endothelial function in spontaneously hypertensive rats

The aim of this study is to elucidate the long term effect of captopril treatment on the endothelial function to release nitric oxide (NO) in spontaneously hypertensive rats (SHR). The properties of endothelium were determined with a model of hindquarter perfusion in response to alpha 1 adrenergic agonist, phenylephrine, at the age of 40 weeks of SHR which was administrated with captopril (100 mg/kg/day) from intrauterine and withdrawn at 16 weeks of age. Furthermore, in the presence of N omega-nitro-L-arginine methyl ester (LNAME), or L-arginine, the responses to phenylephrine were studied. From the curve of perfusion pressure, the minimal, maximal perfusion pressure (PPmin, PPmax) and the maximal slope (slope), as well as the 50% of effective concentration (EC50) were obtained. The data show that in captopril treated SHR, PPmin, PPmax and slope were markedly lower, but EC50 higher than those of untreated SHR. The curve induced by phenylephrine was significantly right shift compared with that of untreated SHR. Like WKY, the intensive reactivity to phenylephrine in the presence of LNAME was much lower than that of untreated SHR. In the presence of L-arginine, however, the right shift of curves was seen only in captopril treated SHR and WKY rats, but not in control SHR. In conclusion, endothelium does involve in the response of resistant vessel to phenylephrine. The mechanism of enhanced reactivity in untreated SHR may be, at least in part, due to the diminished capacity of producing NO from endothelium, and the effect of sustained hypotension of early captopril treatment might be relevant to the improved ability of endothelium.

Tetrandrine inhibited chronic "inflammatory" pulmonary hypertension in rats

AIM

To study the effects of tetrandrine (Tet), on pulmonary hypertension.

METHODS

An "inflammatory" chronic pulmonary hypertension induced by monocrotaline (Mon) in rats was used.

RESULTS

Tet 50, 100, and 150 mg.kg-1.d-1 i.g. 3 wk inhibited Mon-induced increase of pulmonary artery pressure (PAP) by 23.8%, 34.9% (P < 0.05), and 42.0%, (P < 0.05); the right heart index by 2.0%, 25.0%, and 30.0% (P < 0.05) respectively compared with those from Mon group, without significant influence on the systemic artery pressure (SAP). Using histological exam by Verhoeff elastic stain and computer scanning analysis, it was found that Tet (100 mg.kg-1.d-1) for 3 wk, inhibited the increase of medial thickness and cross sectional area by 57.8% (P < 0.01) and 54.6% (P < 0.01), respectively vs Mon group.

CONCLUSION

Tet ameliorated the development of pulmonary vascular and lung tissue injury induced by Mon in rats.

Seven outbreaks of trichinosis in China (1992-1996)

Seven outbreaks of trichinosis occurred in Zhengzhou (central China) from 1992 to 1996, 250 patients were diagnosed. Trichinella larvae were found in 3 of 4 portions of the pork examined and in 5 of 7 cases by muscle biopsy. There was a higher occurrence of outbreaks in winter. Young and middle-aged workers, cadres and merchants were the majority of patients, (higher in males than in females). The most important clinical manifestations were fever, eyelid edema, tiredness and eosinophilia without any gastrointestinal symptoms, rash and with less myalgia. Anti-Trichinella antibodies were detected by IF in 62.6% individuals with the history of infection. The specific antibodies were only observed in 78% patients one week after onset of disease, while the antibody positive rate was increased to 92.5%, 97.6% and 100% two, three, four and five weeks after the onset and evidently increased from 89.6% before therapy to 100% one week after therapy, and decreased to 74.6% and 23.7% one and four months after therapy respectively, which suggested that IF was a useful tool for immunodiagnosis and checking up therapeutic effect of trichinosis.

High-energy defibrillation increases the severity of postresuscitation myocardial dysfunction

BACKGROUND

The fatal outcome of victims after initially successful resuscitation from cardiac arrest has been attributed both to global myocardial ischemia during the interval of cardiac arrest and to the adverse effects of reperfusion. The present study was prompted by earlier experimental observation that the magnitude of myocardial dysfunction was in part related to the energy delivered during electrical defibrillation.

METHODS AND RESULTS

Ventricular fibrillation (VF) was induced in 15 Sprague-Dawley rats. Precordial compression was begun together with mechanical ventilation after 4 minutes of untreated VF and continued for 6 minutes. Spontaneous circulation was restored in each animal after external defibrillation with a single stored 2-, 10-, or 20-J countershock. Cardiac index and the rate of left ventricular pressure rise at left ventricular pressure of 40 mm Hg (dP/dt40) and fall (negative dP/dt) during the 240-minute interval after successful resuscitation were decreased, and left ventricular diastolic pressure was increased. These decreases in myocardial function were closely related to the energy of electrical defibrillation. After a 20-J shock, animals survived for only 5+/-3 hours; after a 10-J shock, animals survived for 15+/-4 hours; and after a 2-J shock, all animals survived for >24 hours.

CONCLUSIONS

The severity of postresuscitation myocardial dysfunction is related, at least in part, to the magnitude of the electrical energy of the delivered shock.

Molecular dissection of two distinct actions of melatonin on the suprachiasmatic circadian clock

The pineal hormone melatonin elicits two effects on the suprachiasmatic nuclei (SCN): acute neuronal inhibition and phase-shifting. Melatonin evokes its biological effects through G protein-coupled receptors. Since the Mel1a melatonin receptor may transduce the major neurobiological actions of melatonin in mammals, we examined whether it mediates both melatonin effects on SCN function by using mice with targeted disruption of the Mel1a receptor. The Mel1a receptor accounts for all detectable, high affinity melatonin binding in mouse brain. Functionally, this receptor is necessary for the acute inhibitory action of melatonin on the SCN. Melatonin-induced phase shifts, however, are only modestly altered in the receptor-deficient mice; pertussis toxin still blocks melatonin-induced phase shifts in Mel1a receptor-deficient mice. The other melatonin receptor subtype, the Mel1b receptor, is expressed in mouse SCN, implicating it in the phase-shifting response. The results provide a molecular basis for two distinct, mechanistically separable effects of melatonin on SCN physiology.

[The mechanisms of progesterone treatment on endometrial carcinoma]

OBJECTIVE

To study the mechanisms of the exogenic progestrerone treatment on endometrial carcinoma.

METHODS

We observed the morphologic changes of the endometrial cancer cells treated by exogenic progesterone with light and electronic microscopy.

RESULTS

The main changes of the tumor cell treated were well differentiation, increase in secretory activity and apoptosis of tumor cells.

CONCLUSIONS

Progesterone may directly affect tumor cells, inhibit the growth of tumor cells and lead to well differentiation. Clinically with preoperative and postoperative progesterone therapy, it can decrease the peritoneum implantation and metastasis, and also decrease the recurrence after operation.

[Clinical observation on 206 cases with lower limb deep venous thrombosis treated by integrated traditional Chinese and Western medicine]

OBJECTIVE

To study the pathogenetic mechanism of lower limb deep venous thrombosis (DVT).

METHODS

Thrombosis test in vitro of 206 cases with lower limb DVT was measured. All of them were treated by integrated traditional Chinese and Western medicine (TCM-WM).

RESULTS

The indexes of thrombosis test in vitro of patients were much higher than those of normal subjects (P < 0.001). The relevent indexes were different in types distribution according to differentiation of symptoms and signs (P < 0.01-0.001) and between before and after treatment (P < 0.001). It showed that hypercoagulability of blood occurred even if after the occurence of DVT. Changes of indexes might be objective parameters for Syndrome Differentiation in TCM. The indexes became lower when state of illness was improving.

CONCLUSION

The therapy of TCM-WM has good efficacy for DVT.

[Operative treatment of vesical diverticula]

We reviewed the results of operative management of 31 patients with vesical deverticula, and introduce a simple technique for treating large bladder diverticula. In the 31 patients with vesical diverticula analysed, 23 were followed up for at least six months. Of the 31 patients, 25 were male and 6 female. The average age was 54.2 years. Diverticula was secondary to bladderoutlet obstruction. Seven cases had intradiverticular tumors, and 9 stones in the sac. The diagnosis of vesical diverticula was usually made by cystogram or ultrasonography. The operative indications for vesical diverticula included stone formation, intradiverticular tumor, ureteral obstruction, incomplete empting diverticulum and urine retention due to large diverticula. The combined extravesical and intravesical method was often used. 26 patients underwent both operations for outlet obstruction and vesical diverticula at the same time. Of the 23 followed-up cases, 21 had no symptoms of the urinary tract. Five of the 7 patients with intradiverticular tumor died within 2.5 years; one of the rest survived for 2 years, and the others for 6 years. Two patients with large vesical diverticula received intravesical separation of diverticula. No complications encountered in this simple, time-saving and safe procedure. Cystograms revealed normal condition. The choice of operative techniques to treat vesical diverticula varies with each individual patient. The technique of intravesical separation of vesical diverticula is suitable for large, adhesive and posterior diverticula.

Action of autonomic drugs on the in vivo bladder base and proximal urethra in dog

OBJECTIVE

To investigate the effects of autonomic drugs on the in vivo bladder base and proximal urethra in order to provide some reference materials for clinical usage of these drugs in the treatment of bladder outlet dysfunction.

METHODS

In 35 dogs, the bladder base was separated from the bladder body and closed to constitute a small chamber. The changes of the pressure in the bladder base chamber and proximal urethra were recorded synchronously before and after administration of autonomic drugs. All data were analyzed with Student's t test.

RESULTS

The bladder base had little response to acetylcholine (Ach) which however promoted a contraction of the proximal urethra. The effect of Ach on the proximal urethra was antagonized by phentolamine, but not by atropine. Isoprenaline resulted in relaxation of the bladder base, though it had little effect on the urethra. Norepinephrine (NE) produced contraction of the bladder base and urethra, while phentolamine caused a reduction in the bladder base and urethral pressure, and blocked the response of the bladder outlet region to NE. Angiotensin amide (AII) caused contraction of the bladder base and urethra, which was not obliterated by phentolamine.

CONCLUSIONS

The cholinergic drug has no influence on the in vivo canine bladder base, but causes a contraction of the proximal urethra through indirect activation of alpha-receptors. The alpha-adrenergic agents have great effects on the bladder base and urethra by acting on alpha-receptors within the musculature in the outlet region. The beta-adrenoceptor agonist results in relaxation of the bladder base, but it has no effect on the urethra.

[Preliminary study on the arsenic trioxide-induced NB4 cell apoptosis and its molecular mechanisms]

OBJECTIVE

To illustrate the possible cellular and molecular mechanisms of arsenic trioxide (As2O3) in the treatment of acute promyelocytic leukemia (APL).

METHODS

APL cell line NB4 was used for in vitro studies. The effect of As2O3 on APL was studied by using flow cytometry, DNA electrophoresis, Narthern blotting and Western blotting.

RESULTS

As2O3 induced NB4 cell apoptosis, while not inhibiting the growth and survival of two other leukemic cell lines (HL-60 and U937). Furthermore, As2O3 effectively down-regulated the expression of bcl-2 gene without changing the mRNA levels of other apoptosis-associated genes (including p53, c-myc, bax and bcl-XL).

CONCLUSION

These might be one of the molecular mechanisms of As2O3 induced NB4 cell apoptosis.

Analysis of the human env-specific cytotoxic T-lymphocyte (CTL) response in natural human immunodeficiency virus type 1 infection: low prevalence of broadly cross-reactive env-specific CTL

Major histocompatibility complex-restricted cytotoxic T lymphocytes (CTL) are part of the cellular immune response to persistent virus infections. Candidate vaccines against human immunodeficiency virus type 1 (HIV-1) should elicit broad cross-reactive immunity to confer protection against different strains of HIV-1. As it is likely that candidate vaccines will include the envelope gene product Env, we determined the proportion of CTL clones which recognized variable and conserved determinants in three env variants during natural infection. Limiting dilution analysis was used to characterize numerous short-term CTL clones derived from peripheral blood of HIV-1-infected subjects, using split-well analysis to assay cytotoxicity against target cells expressing gp160env of HIV-1 strains IIIB, MN, and RF. In 9 of 12 HIV-1-infected subjects, at the clonal level most env-specific CTL recognized determinant(s) within one env variant but not in the other variants. In some subjects, CTL recognized multiple nonconserved determinants in different variants. The pattern of recognition of different env variants was relatively stable over time. In most of the patients studied, the proportion of CTL which showed cross-recognition of conserved determinants shared among the three strains was low. Two novel CTL epitopes within gp41 were identified by using 15-mer peptides of the HIV-SF2 sequence. When specific peptide was used to stimulate CTL precursors in vitro, the frequency of peptide-specific CTL precursors was very high, but the CTL elicited by this stimulation were highly strain specific. We conclude that the use of a single HIV env variant to detect CTL activity can underestimate the magnitude and complexity of the env-specific CTL response. The low prevalence of CTL clones which show cross-recognition of conserved determinants may have implications for immunization strategies based solely on env; to elicit broadly cross-reactive CTL other, more conserved viral antigens are likely to be needed in addition to env. Because of its capacity to distinguish CTL responses against different virus strains, limiting dilution analysis is particularly appropriate to quantitate the immune responses generated by candidate env-based vaccines.

[Preventive effects of tetrandrine on pulmonary hypertension and right ventricular hypertrophy in rats induced by monocrotaline]

Pulmonary hypertension and right ventricular hypertrophy in rats were developed 3 weeks after administration of monocrotaline 50 mg/kg i.p. Tetrandrine 10 mg/kg and 15 mg/kg bid p.o. could prevent the above-said effects produced by monocrotaline.

Inhibition of esophageal cancer proliferation by adenovirally mediated delivery of p16INK4

We have been investigating the molecular basis of esophageal carcinogenesis in an attempt to develop gene therapy of established esophageal cancers and premalignant esophageal lesions. In this report we demonstrate the efficacy of adenovirally mediated p16 gene replacement in esophageal squamous cell cancers. Adenoviral p16 efficiently transduced epidermoid cancer cells containing p16 mutations, and expression of exogenous p16 in these cells correlated with G1 cell cycle arrest and profound growth inhibition. No effects were observed in esophageal adenocarcinoma cells due to extremely poor transduction of these cells by adenovirus. These results may have implications regarding the design of clinical trials using p16 gene replacement strategies for intervention in esophageal cancers.

The human cytotoxic T-lymphocyte (CTL) response to cytomegalovirus is dominated by structural protein pp65: frequency, specificity, and T-cell receptor usage of pp65-specific CTL

Cytotoxic T lymphocytes (CTL) appear to play an important role in the control of human cytomegalovirus (HCMV) in the normal virus carrier: previous studies have identified peripheral blood CD8+ CTL specific for the HCMV major immediate-early gene product (IE1) and more recently, by bulk culture and cloning techniques, have identified CTL specific for a structural gene product, the lower matrix protein pp65. In order to determine the relative contributions of CTL which recognize the HCMV proteins IE1, pp65, and glycoprotein B (gB) to the total HCMV-specific CTL response, we have used a limiting-dilution analysis system to quantify HCMV-specific CTL precursors with different specificities, allowing the antigenic specificity of multiple short-term CTL clones to be assessed, in a group of six healthy seropositive donors. All donors showed high frequencies of HCMV-specific major histocompatibility complex-restricted CTL precursors. There was a very high frequency of CTL specific for pp65 (lower matrix protein); IE1-specific CTL were also detectable at lower frequencies in three of five donors, while CTL directed to gB were undetectable. A pp65 gene deletion mutant of HCMV was then used to estimate the contribution of pp65-specific CTL to the total HCMV-specific CTL response; this showed that between 70 and 90% of all CTL recognizing HCMV-infected cells were pp65 specific. Analysis of the peptide specificity of pp65-specific CTL showed that some donors have a highly focused response recognizing a single peptide; the T-cell receptor Vbeta gene usage in these two donors was shown to be remarkably restricted, with over half of the responding CD8+ T cells utilizing a single Vbeta gene rearrangement. Other subjects recognized multiple pp65 peptides: nine new pp65 CTL peptide epitopes were defined, and for five of these the HLA-presenting allele has been identified. All four of the HLA A2 donors tested in this study recognized the same peptide. This apparent domination of the CTL response to HCMV during persistent infection by a single structural protein, irrespective of major histocompatibility complex haplotype, is not clearly described for other persistent virus infections, and the mechanism requires further investigation.

[The trend of changes in etiologic types of heart diseases in Shanghai from 1948 to 1989]

Analysis of the data from 7188 cases seen in the 1980s two general hospitals in Shanghai and comparison of the data with those in the 1950s, 1960s and 1970s revealed that the percentage of heart diseases among the inpatients in medical wards increased in each decades, from 9.89%, 15.69% 20.91% to 23.54% respectively. The constituent ratios of different etiologic types of heart diseases changed. Coronary heart disease constituted the largest proportion, next in number was rheumatic heart disease and congenital heart disease was in the third place. The incidence of congenital heart diseases, myocarditis, cardiac dysrhythmias without organic heart diseases, cardiomyopathy and endocarditis increased and that of rheumatic heart disease, pulmonary heart disease and hypertensive heart disease apparently decreased, syphilitic heart disease was rarely encountered.

[The epidemiological and clinical features of 208 patients with trichinosis]

In order to know the epidemiological and clinical features of trichinosis, the data of 208 patients with trichinosis from 1992 to 1994 were analysed. The results showed that these patients came from 11 districts, and acquired the infection mainly by tasting the raw pork filling for dumplings or ingesting instant-boiled pork or mutton. The incidence of trichinosis is high in winter. Young and middle-aged workers and cadres constituted the majority of the patients and the infection was more common in the males than in females. The main clinical manifestations of trichinosis were prolonged fever, general myalgia, muscle weekness and eosinophilia. Most of the patients had no gastrointestinal symptoms and skin eruption. Eyelid edema was only seen in the early stage. Serological tests were significant value in the diagnosis of trichinosis. The key measures to prevent trichinosis were that meat inspection should be strictly carried out and bad eating habit changed.

[Role of sensory neuropeptides in the responses of pulmonary and cerebral blood vessels to acute hypoxia in rats]

OBJECTIVE

To study the effects of sensory neuropeptides on pulmonary circulation and cerebral blood flow during acute hypoxia in SD rats.

METHODS

The changes in hypoxic pulmonary vasoconstriction (HPV) and hypoxic cerebral vasodilatation (HCVD) were observed in mature SD rats pretreated with capsaicin (50 mg/kg) when they were newborn. The hypoxic changes of plasma substance P in the pulmonary circulation and the peptidergic nerve fibers in the lungs were determined with radioimmunoassay and immunohistochemical staining respectively. The effects of exogenous SP on HPV and HCVD were studied as well.

RESULTS

The mean pulmonary artery pressure (2.46 +/- 0.07kPa), pulmonary vascular resistance (3665.09 +/- 164.08kPa.s/L) and the percentage change of pulmonary vascular resistance (delta PVR%) during hypoxia (98.67% +/- 4.07%) in group capsaicin (Caps) were higher than those in group Veh (vehicle control) (2.22 +/- 0.04 kPa, 2945.14 +/- 119.23kPa.s/L and 41.21% +/- 2.08% respectively) (t = 2.89, 3.49 and 12.18, P < 0.01) and those in group NC (normal control) (2.22 +/- 0.03 kPa, 2908.19 +/- 130.85 kPa.s/L and 39.13% +/- 1.48%) (t = 3.09, 3.59 and 13.48, P < 0.01). The wave amplitude in rheoencephalogram (H) in group Caps (11.27 +/- 1.02 m omega) was less than those in group Veh (14.96 +/- 1.08 m omega) (t = 2.49, P < 0.05) and group NC (15.86 +/- 1.33 m omega) (t = 2.69, P < 0.05) during normoxia. It increased significantly in groups Veh (41.36% +/- 6.74%) (t = 9.44, P < 0.01) and NC (48.79 +/- 6.10%) (t = 11.21, P < 0.01) during acute hypoxia, however it dropped in group Caps (-23.55 +/- 2.38%). The plasma SP-like immunoreactivity level in the outflow blood of pulmonary circulation increased in hypoxic rats (SPop-SPip = 139.04 +/- 27.97 pmol/L) while it decreased in group Caps (SPop-SPip = -45.84 +/- 6.52 pmol/L) (t = 5.41, P < 0.01). The SP- and CGRP-immunoreactive fibers in lungs appeared to be sparser and thinner during hypoxic inspiration for 3-5 min. SP decreased delta PVR% from 47.42% +/- 4.70% to 20.58% +/- 2.66% (t = 6.84, P < 0.01) while it increased delta H% from 12.51% +/- 4.31% to 37.66% +/- 5.17% (t = 3.93, P < 0.01) during hypoxia.

CONCLUSIONS

Sensory neuropeptides might contribute to the modulation of the basic tone of pulmonary and cerebral vessels. They could be released during acute hypoxia modulating HPV and mediating HCVD.

[The role of hypergastrinemia in the pathogenesis of intussusception in infants]

From 1988 to 1992 the serum gastrin levels of 124 patients with intussusception and 20 normal infants and 15 patients with intestinal obstruction under 3 years of age were measured. Serum cAMP levels of 10 normal infants and 10 patients with intussusception were determined. In animal experiment study, the pressures of ileum cavity and ileoceal valve were determined before and after injectting pentagastrin into the veins of 8 young dogs. The levels of gastrin (219.9 +/- 100.6 pg/ml) and cAMP (32.4 +/- 7.6 pmol/ml) were higher in patient group than in the control group. (89 +/- 3 pg/ml, P < 0.05 and 22.2 +/- 7.5 pmol/ml P < 0.05). The result of animal experiment showed that the effect of gastrin and etiology of intussusception are identical. The main physiological funcitons of gastrin is to increase the intestinal peristalsis and relax the ileocecal sphincter. Our study showed that hypergastrinemia may be the basis etiologic factor of intussusception. Main clinical feactures were explained by this new theory.

Comparative study of nickel toxicity to growth and photosynthesis in nickel-resistant and -sensitive strains of Scenedesmus acutus f. alternans (Chlorophyceae)

Nickel (Ni) toxicity to growth and photosynthesis was studied in four strains of Scenedesmus acutus f. alternans. Effects of Ni dosage and duration of exposure on growth and photosynthesis were strain specific. Large differences in responses of both growth and photosynthesis to Ni were detected between three resistant strains (B4, Cu-Tol, and Ni-Tol) and one sensitive strain (UTEX 72). Growth of UTEX 72 was ≥ 18 times more sensitive to Ni than those of the three resistant strains. The order of Ni dosages (fmol Ni/pg cell dry weight) causing 50% inhibition (D150) of growth rates in the four strains was Ni-Tol (10.5) > B4 (8.19) > Cu-Tol (4.60) > UTEX 72 (0.25). The effect of Ni dosage on photosynthetic rate as percentage of control corresponded to a saturation curve and was a strong function of duration of exposure. The DI50s of photosynthetic rates were ≥3.5 times lower in UTEX 72 than in the three resistant strains, and in all four strains they decreased sharply with the increase in duration of exposure. The order of the four strains in DI50s of photosynthetic rate was B4 (58.2) > Cu-Tol (38.0) > Ni-Tol (28.9) > UTEX 72 (8.24) for 6-h exposure and Ni-Tol (2.88) > Cu-Tol (1.30) > B4 (1.01) > UTEX 72 (0.15) for 24-h exposure. The DI50s of photosynthetic rate for 6-h exposure were higher than those of growth rate in all four strains, and for 24-h exposure they were lower, except in UTEX 72. Thus, the relative Ni sensitivity of growth and photosynthesis of the four strains depends on the duration of exposure. The results of factorial analysis of variance suggested that Ni toxicity to photosynthesis is a consequence of a strong interaction among strain, Ni dosage, and duration of exposure.

Factors accounting for different responses of pulmonary and cerebral vessels to hypoxia

The roles of sympathicus, sensory neuropeptides (SNP), cyclooxygenase metabolites (COX-M), lipoxygenase metabolites (LOX-M), endothelium derived relaxing factor (EDRF), reactive oxygen (ROS) and potassium channels (PC) in the hypoxic pulmonary vasoconstriction (HPV) and hypoxic cerebral vasodilation (HCVD) were investigated in intact rats, rabbits and dogs. The results showed that during hypoxia, the excitation of sympathicus caused a constriction of both pulmonary and cerebral vessels, while SNP, EDRF and the opening of voltage sensitive PC caused the dilation of both of them; LOX-M mediated HPV and HCVD, COX-M might serve as their modulators; the blockade of ATP sensitive PC induced by hypoxia mediated HPV, but had no effect on HCVD; the reduction of O2-. in the lung might potentiate HPV, however, O2-. remained unchanged in brain during hypoxia. It is suggested that the alterations of LOX-M, ROS and the ATP sensitive PC are the factors accounting for the difference in the response of pulmonary and cerebral vessels to hypoxia.

Stopped-flow kinetic study of the reaction of ascorbic acid with peroxynitrite

A new mechanism is presented for the oxidation of ascorbate by peroxynitrite. Our mechanism involves the reaction of ascorbate both with ground-state peroxynitrous acid (HOONO) and with a reactive intermediate (HOONO*); the reactive intermediate is postulated to be formed in the decay of HOONO to form nitrate. At physiological pH, the ascorbate monoanion (AH-) is the predominant ascorbate species. The plot of the observed rate constant for peroxynitrite decay (kobs) vs AH- for the reaction of peroxynitrite with AH- shows two regions, one linear and one curved. In the linear region, which involves high AH- concentrations, the reaction is dominated by the bimolecular reaction between HOONO and AH-. At lower AH- concentrations, this bimolecular reaction slows and reactions with both HOONO and HOONO* produce the observed curvature. Analysis of the data leads to the estimation of the ratio of rate constants for the reaction of AH- with HOONO* (k2*) and the decay of HOONO to nitrate (kN), giving the value of k2*/kN = 3158 +/- 505 M-1; and of the rate constant (k2) for the reaction between AH- and HOONO, k2 = 236 +/- 14 M-1 s-1. Ascorbate displays higher selectivity for HOONO* than does methionine or 2-keto-4-thiomethylbutanoic acid, two substrates whose reactivity toward HOONO and HOONO* has previously been reported. The biological relevance of the reaction of ascorbate with peroxynitrite is discussed in terms of the rate constants and the concentrations of AH- typically found in biological systems; ascorbate may react with HOONO*, although the reaction with ground-state HOONO probably is too slow to occur in vivo.