[The different responses to anoxia in cultured CA1 and DG neurons from newborn rats]

Tissue culture from hippocampal CA1 or dentate gyrus (DG) region was established on the basis of previous neuronal culture technique. The viability, intracellular calcium concentration and brain-derived neurotrophic factor (BDNF) mRNA expression of the two kinds of neurons after anoxia were observed in the counting in the confocal microscopic field and in situ hybridization. It is found that DG neurons are not only more resistant to anoxia, but also have a stronger ability to keep calcium homeostasis and to express BDNF mRNA than CA1 neurons.

Design of potent and selective human cathepsin K inhibitors that span the active site

Potent and selective active-site-spanning inhibitors have been designed for cathepsin K, a cysteine protease unique to osteoclasts. They act by mechanisms that involve tight binding intermediates, potentially on a hydrolytic pathway. X-ray crystallographic, MS, NMR spectroscopic, and kinetic studies of the mechanisms of inhibition indicate that different intermediates or transition states are being represented that are dependent on the conditions of measurement and the specific groups flanking the carbonyl in the inhibitor. The species observed crystallographically are most consistent with tetrahedral intermediates that may be close approximations of those that occur during substrate hydrolysis. Initial kinetic studies suggest the possibility of irreversible and reversible active-site modification. Representative inhibitors have demonstrated antiresorptive activity both in vitro and in vivo and therefore are promising leads for therapeutic agents for the treatment of osteoporosis. Expansion of these inhibitor concepts can be envisioned for the many other cysteine proteases implicated for therapeutic intervention.

Determinants of plasma platelet-activating factor acetylhydrolase: heritability and relationship to plasma lipoproteins

Plasma platelet-activating factor acetylhydrolase (PAF-AH) is the enzyme that inactivates PAF (1-alkyl-2-acetyl-sn-glycero-3-phosphocholine). We determined the relative contributions of genetic and environmental factors to variation in plasma PAF-AH activity in 240 individuals from 60 nuclear families. Regression of mean-offspring PAF-AH activity on the mid-parent value indicated that 62% of the variation in plasma PAF-AH activity was heritable. Spousal values were weakly negatively correlated, indicating that familial aggregation of PAF-AH activity is due to genetic rather than to environmental factors. Among normolipidemic individuals, plasma PAF-AH activity was strongly correlated with the plasma concentration of low density lipoprotein cholesterol (LDL-C), and treatment with lovastatin resulted in proportional decreases in plasma PAF-AH activity and LDL-C concentrations. To further elucidate the relationship between PAF-AH and plasma concentrations of LDL, plasma PAF-AH activity was measured in families with well-defined, monogenic disorders of LDL metabolism. Plasma PAF-AH activity cosegregated with plasma LDL-C concentrations in familial hypercholesterolemia, but not in familial hypobetalipoproteinemia. We speculate that the rate of removal of LDL from the circulation may determine the clearance rate of PAF-AH, thereby modulating the activity of PAF-AH in blood.

A new distinctive variation of renal arterial vascularization

In addition to the usual renal arteries, a bilateral artery branching from the aorta was found connecting the aorta to both kidneys in an 82 year-old Caucasian man. By creating an additional blood supply to the kidneys this artery may have had an effect on renal perfusion.

Path test reactions to the Chinese Standard Screening Allergens in 1,135 patients investigated for allergic contact dermatitis

BACKGROUND

The patch test has become the standard method of investigating patients with allergic contact dermatitis. Many countries have developed standard screening allergens to make patch testing more efficient. A series of the Chinese Standard Screening Allergens were studied and modified.

OBJECTIVE

This study investigated the frequency of contact allergies in suspected allergic contact dermatitis and tested the practicality of the Chinese Standard Screening Patch Test Allergens.

METHODS

A total of 1,135 patients suspected of having allergic contact dermatitis were patch tested. Three hundred twelve (27.5%) were men, and their age ranged from 2 to 75 years old (mean age, 34.3 years), 823 (72.5%) were women, and their age ranged from 2 to 76 years old (mean age, 33.0 years). Nanjing Medical University supplied the Chinese Standard Screening Allergens and Finn-Chamber. All patients were patch tested according to the Chinese Standard Screening Patch Test Allergens with Finn-Chamber the protocol as established by the International Contact Dermatitis Research Group (ICDRG).

RESULTS

From the 1,135 patients suspected to have allergic contact dermatitis, 650 (57.3%) had at least one positive reaction. Nineteen (95%) of the Chinese Standard Screening Patch Test Allergens had positive reactions higher than 1%. Of 485 patients with negative reaction to the Standard Allergens, 106 patients were tested with other suspected contactants according to history. Thirty-nine (36.8%) had positive reactions to the contactants they provided. The total positive rate therefore increased by 3.4%.

CONCLUSIONS

Our study results indicate that the Chinese Standard Screening Patch Test Allergens are suitable for use in routine clinic in China.

Involvement of activator protein-1 (AP-1) in induction of apoptosis by vitamin E succinate in human breast cancer cells

The purpose of this study was to document induction of apoptosis by vitamin E succinate (VES; RRR-alpha-tocopheryl succinate) in human breast cancer cells in culture and to characterize potential c-jun involvement. VES at 18.8 microM (10 micrograms/mL) induced DNA synthesis arrest, reduced total cell numbers, and induced apoptosis in estrogen receptor-positive and estrogen-responsive MCF-7 human breast cancer cells. VES at 10 micrograms/mL induced apoptosis in greater than 60% of cells within 3 d of treatment. Apoptosis was documented by detection of fragmented or condensed nuclei in 4',6-diamindino-2-phenylindole-stained cells, detection of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeled DNA, and DNA laddering. Analyses of mRNA and protein levels of candidate molecules involved in apoptosis showed that MCF-7 cells treated with VES exhibited elevated and persistent expression of c-jun. MCF-7 cells stably transfected with a dominant-negative interfering mutant c-jun, TAM-67, and expressing high levels of mutant jun exhibited approximately 50% blockage of VES-mediated apoptosis. In addition to increased c-jun expression after VES treatment, VES-treated MCF-7 cells exhibited elevated activator protein-1 (AP-1) binding activity. Comparisons of AP-1 binding factors by super-shift analyses with jun-specific antibodies in cells sensitive to VES-induced apoptosis (empty-vector control 7-1 cells) and cells resistant to VES-induced apoptosis (TAM-67-containing TAM-9 cells) showed that the sensitive cells expressed c-jun and jun D and the resistant cells TAM-67 AP-1 binding proteins after VES treatment. These studies suggested that c-jun may be involved in the apoptotic process initiated by VES treatment of human MCF-7 breast cancer cells.

Processing of Alzheimer's amyloid precursor protein during H2O2-induced apoptosis in human neuronal cells

The processing of Alzheimer's amyloid precursor protein was studied by Western blotting during H2O2 induced apoptosis in cultures of human neuroblastoma cells. A new 5.5 kDa fragment putatively containing intact A beta was detected and found to be highly associated with apoptosis. The results suggest a possible vicious cycle involving H2O2, A beta and apoptosis which may contribute to the neuronal death mechanism in Alzheimer's Disease.

Effects of gamma interferon and nitric oxide on the interaction of Mycobacterium avium subsp. paratuberculosis with bovine monocytes

In this study, we examined the effects of recombinant bovine gamma interferon (rIFN-gamma) and nitric oxide (NO) on the interaction of M. avium subsp. paratuberculosis with bovine monocytes. Monocytes pretreated with rIFN-gamma exhibited slightly increased phagocytosis of M. avium subsp. paratuberculosis and modest inhibition of the intracellular growth of this microorganism. The number of viable intracellular bacilli decreased earlier in rIFN-gamma-pretreated monocytes than in control monocytes. After infection with M. avium subsp. paratuberculosis, NO was not constitutively released, but NO release from infected monocytes was induced by treatment with rIFN-gamma or with rIFN-gamma and lipopolysaccharide (LPS). Release of nitric oxide was inhibited by addition of N(G)-monomethyl-L-arginine; however, inhibition of nitric oxide did not alter the pattern of intracellular survival of M. avium subsp. paratuberculosis in rIFN-gamma-treated bovine monocytes. Although chemically generated nitric oxide killed M. avium subsp. paratuberculosis in a cell-free system in vitro, the amount of nitric oxide required was far greater than that released from infected monocytes stimulated with rIFN-gamma and LPS. Our data suggest that rIFN-gamma activates M. avium subsp. paratuberculosis-infected bovine monocytes to release nitric oxide but only modestly increases antimycobacterial activity of monocytes against this organism. This may be due, in part, to the fact that the amount of nitric oxide produced by rIFN-gamma-activated bovine monocytes is insufficient to kill intracellular M. avium subsp. paratuberculosis bacilli in vitro.

[Facial proportions of the young with the beautiful faces of Sichuan descent]

In this study, eighteen indexes of facial proportions were established in 72 youngsters with beautiful faces of Sichuan descent, who haven't been done operation on and orthodontics in our country. The results indicated that there were not most sexual difference of the facial proportions between male and female in most indexes, and also were not national difference of facial proportions between Chinese and Japanese. It also showed some progresses in clinical practice.

Effect of quantization error on the computed phase of phase-shifting measurements

The effect of the quantization of fringe intensity on the phase error in phase-shifting measurements is formulated by a characteristic polynomial method. A numerical simulation is performed, and its result is in good agreement with the analytical one. Several factors influencing the quantization effects are investigated.

[Impact of nitric oxide on endothelin gene expression in intrapulmonary arteries of chronic hypoxic rats]

OBJECTIVE

To investigate the impact of nitric oxide on endothelin-1 (ET-1) mRNA expression in pulmonary artery endothelial cells and pulmonary artery smooth muscle cells of chronic hypoxic rats.

METHODS

In situ hybridization was performed on lung sections from 40 chronic hypoxic rats treated either with L-Arginine (L-Arg) or N omega-nitro-L-arginine methyl ester (L-NAME) by using cRNA probe for ET-1.

RESULTS

Most intrapulmonary arteries had 1%-50% of the endothelial cells expressing ET-1 mRNA in both one-week and two-week hypoxic rats (75% +/- 3% and 71% +/- 6%, respectively), which was significantly inhibited by L-Arg but augmented by L-NAME administration. Most pulmonary artery smooth muscle cells showed no ET-1 mRNA signals in both one-week and two-week hypoxic rats (85% +/- 6% and 98% +/- 2%, respectively). However, L-NAME increased ET-1 mRNA expression in pulmonary artery smooth muscle cells of hypoxic rats.

CONCLUSION

Nitric oxide inhibited ET gene expression in both pulmonary artery endothelial cells and smooth muscle cells of rats exposed to chronic hypoxia.

Acute acalculous cholecystitis with a decrease in CD4/CD8 ratio

Acute acalculous cholecystitis (AAC) usually occurs in the elderly and in those with severe pre-existing pathological conditions. However, there have recently been reports of AAC in relatively young immunosuppressed patients, such as those with acquired immunodeficiency syndrome (AIDS). We report here a 27-year-old woman with AAC who received an emergent cholecystectomy. Although anti-human immunodeficiency virus antibody (anti-HIV) was not detected, a decrease in the CD4/CD8 ratio in sera was found. This rare case of AAC in a patient with decreased CD4/CD8 ratio who showed no other related diseases suggests that surgeons should keep in mind the possible presence of immunosuppression in this condition.

Appleby operation for carcinoma of the body and tail of the pancreas

Long-term survival of carcinomas in the body and tail of the pancreas after surgery is still rare. One of the major reasons for unresectability is cancerous invasion to major vessels, such as the common hepatic and splenic arteries. Resection of the involved arteries can increase resectability and thus might increase post-operative survival. The aim of this study was to clarify the importance of the Appleby operation for carcinoma of the body and tail of the pancreas. A Case Report was carried out with a 54 year-old man, had suffered back pain and loss of body weight for six months. Imaging procedures such as US, CT or angiography showed a carcinoma in the body of the pancreas, about 3 cm in size, and both the common hepatic and splenic arteries were invaded by the tumor. The Appleby operation was used for this patient, since firstly there was no invasion to the head of the pancreas, secondly neither the proper hepatic artery nor the SMA was involved, thirdly the root of the CA was free of carcinoma, and finally because clear pulsation of the proper hepatic artery could be felt one or two minutes after occlusion of the CHA, which indicated that resection of the CHA would not lead to hepatic ischemia. The postoperative course was uneventful. His appetite recovered well and his body weight increased to the level before the disease. The patient was relieved from back pain and has returned to work 18 months after the operation, although he had a local recurrence eight months after the operation. In addition, eleven cases with carcinoma of the body and tail of the pancreas were used for a literature review. The average survival time after the Appleby operation is 6.6 months, and four patients are still alive. One patient has survived 13 years after the operation. It was concluded that although the prognosis after Appleby procedure is still not satisfactory that this operation can at least offer patients a better quality of life.

Renal cell carcinoma of the spindle cell type with metastasis to the pancreas: a case report

We report a case of renal cell carcinoma in a 49-year-old man with multiple metastases, including some to the pancreas which were initially diagnosed as primary pancreatic carcinoma. The first clinical manifestation was jaundice caused by a large metastatic lymph node. Computed tomography showed tumors in the body and tall of the pancreas as well as in the left kidney. Angiography showed that all of the lesions were hypervascular. The patient was finally diagnosed as having renal cell carcinoma. Cholecystectomy and choledochojejunostomy were performed. Intraoperative biopsy of the lymph nodes along the common hepatic artery showed spindle cell carcinoma which was compatible with renal cell carcinoma. Since renal cell carcinoma with pancreatic metastasis is rare, special attention should be paid to its differentiation from primary pancreatic carcinoma in patients with tumors in both the pancreas and kidneys.

Expression of mutant amyloid precursor proteins induces apoptosis in PC12 cells

The cause of neuronal loss in Alzheimer disease is unknown. We investigated the effects on survival of PC12 cells expressing A692G, E693Q, and V717F mutant amyloid precursor proteins (APP). Differentiated cells expressing mutant APPs exhibited somal shrinkage, followed by cell detachment from the plates. Increased levels of oligonucleosome-sized DNA ladders and TUNEL-positive nuclei were observed, and electron microscopy revealed extensive plasma membrane blebbing, margination of condensed chromatin, and well-preserved organelles in these transfectants. The levels of TUNEL-positive cells, analyzed by a flow-cytometric method, were increased by four- to sevenfold in mutant APP transfectants, but less than twofold in wild-type APP transfectants relative to untransfected cells. Our results provide evidence that expression of mutant APPs in differentiated PC12 cells induces cell death via an apoptotic pathway.

Effect of dexamethasone on rat plasma platelet activating factor acetylhydrolase during the perinatal period

It has been previously reported that the administration of dexamethasone (DEX) to adult rats increases the activity of plasma platelet-activating factor acetylhydrolase (PAF-AH) and prevents the development of intestinal necrosis caused by platelet activating factor (PAF) injection. In this report, we examined the effect of DEX administration on plasma PAF-AH activity during the perinatal period. Timed-pregnant rats received DEX (0.2-1.0 mg/kg/d) or normal saline (controls) on days 16-18 (early group) or days 18-20 (late group) of gestation. Maternal plasma PAF-AH activity was lower in late gestation than in postpartum period (P < 0.001). Fetal and neonatal plasma PAF-AH activity was higher than maternal values (P < 0.05). No changes of PAF-AH activity were seen in maternal, fetal or neonatal plasma after prenatal DEX administration at the aforementioned doses. A higher dose of DEX (1.3 mg/kg/d x 4d) or cortisone (200 mg/kg/d) produced an elevation of maternal plasma PAF-AH activity (DEX 79.2+/-3.0, cortisone 70.5+/-1.9 vs. controls 49.4+/-2.3 nmol/min/ml, P < 0.01), but resulted in a high fetal mortality. Treatment of newborn rats with DEX (0.5 mg/kg/d) on days 1-3 after birth, increased plasma PAF-AH activity on day 4 (DEX 292+/-5 versus controls 140+/-9 nmol/min/ml, P < 0.001) and day 6 (DEX 302+/-12 versus controls 136+/-6 nmol/min/ml, P < 0.001). Postnatal administration of DEX increases the plasma PAF-AH activity in the rat. Only high doses of prenatal corticosteroids that cause fetal death can elevate maternal plasma PAF-AH activity.

Oxidized low-density lipoprotein increases endothelial intracellular calcium and alters cytoskeletal f-actin distribution

Central to the pathogenesis of atherosclerosis is an abnormally functioning endothelium and a consequent loss of vascular integrity. These abnormalities may be induced by haemodynamic factors, biochemical substances, and also by oxidatively modified low-density lipoprotein (LDL). To understand the mechanism by which oxidized LDL causes endothelial dysfunction, human umbilical vein endothelial cells (HUVECs) were loaded with FURA-2, and intracellular calcium mobilization was studied in acute (seconds after LDL was injected) or chronic (24 h after LDL was injected) preparations. Our results demonstrate that 100 microg mL(-1) oxidized LDL increases HUVEC intracellular calcium. In contrast, native LDL at this same concentration had no effect. In addition, chronic exposure (24 h) of HUVECs to oxidized LDL significantly increases HUVEC intracellular calcium. Fluorescent photomicrographs of HUVECs stained with BODIPY-phalloidin f-actin indicates that oxidized LDL causes a reorganization of microfilaments. The results of this study demonstrate that the mechanism by which oxidized LDL causes a loss of vascular integrity could be through activation of endothelial cells to increase cytosolic calcium, which alters the endothelial barrier by reorganizing the cytoskeleton.

Studies on protective mechanisms of four components of green tea polyphenols against lipid peroxidation in synaptosomes

The comparison of the protective effects of four components of "green tea polyphenols' (GTP) - (-)-epigallocatechin gallate, EGCG; (-)-epicatechin gallate, ECG; (-)epigallocatechin, EGC; and (-)epicatechin, EC - against iron-induced lipid peroxidation in synaptosomes showed that: (1) the inhibitory effects of those compounds on TBA reactive materials from lipid peroxidation decreased in the order of EGCG > ECG > EGC > EC; (2) the scavenging effects of those compounds on lipid free radicals produced by lipid peroxidation could be classified as follows: ECG > EGCG > EC > EGC. Furthermore, we investigated the iron-chelating activity and the free radical scavenging activity of those compounds as their protective mechanisms against lipid peroxidation in synaptosomes. As for the iron-chelating activity, the ratio of EGC, EGCG, ECG or EC to iron(III) was 3:2, 2:1, 2:1 and 3:1, respectively. The hydroxyl radical (HO) scavenging activity of those compounds was investigated in a photolysis of the H2O2 system. It was found that their ability to scavenge hydroxyl radicals decreased in the order of ECG > EC > EGCG >> EGC. It was also found that they could scavenge lipid free radicals in the lecithin/lipoxidase system and their scavenging activity was classified as follows: ECG > EGCG >> EGC > EC. Moreover, we found that their antioxidant active positions were different from each other and the stability of the semiquinone free radicals produced by those compounds in NaOH solution decreased in the order of EGCG > ECG >> EC. The results indicated that the ability of those compounds to protect synaptosomes from the damage of lipid peroxidation initiated by Fe2+/Fe3+ was dependent not only on their iron-chelating activity and free-radical scavenging activity, but also on the stability of their semiquinone free radicals.

Participation of presenilin 2 in apoptosis: enhanced basal activity conferred by an Alzheimer mutation

Overexpression of the familial Alzheimer's disease gene Presenilin 2 (PS2) in nerve growth factor-differentiated PC12 cells increased apoptosis induced by trophic factor withdrawal or beta-amyloid. Transfection of antisense PS2 conferred protection against apoptosis induced by trophic withdrawal in nerve growth factor-differentiated or amyloid precursor protein-expressing PC12 cells. The apoptotic cell death induced by PS2 protein was sensitive to pertussis toxin, suggesting that heterotrimeric GTP-binding proteins are involved. A PS2 mutation associated with familial Alzheimer's disease was found to generate a molecule with enhanced basal apoptotic activity. This gain of function might accelerate the process of neurodegeneration that occurs in Alzheimer's disease, leading to the earlier age of onset characteristic of familial Alzheimer's disease.

[Determination of puerarin in gegen ginlian tablets by RP-HPLC]

A quantitative method was developed for the determination of puerarin in Gegen Qinglian Tablets by reversed phase HPLC. Chromatographic conditions included column ODS-C18, column temperature: 35 C, UV detector: 250 nm, mobile phase: EtOH-H2O (23:77), flow rate: 1 ml/min. The number of theoretical plates calculated for puerarin peak was no less than 2000. The standard curve was linear in the concentration range of 5-80 micrograms/ml, and the correlation coefficient was 0.9999. The average recovery and the relative standard deviation were 97.6% and 1.8% respectivily.

Effects of nicotinamide on prevention and treatment of streptozotocin-induced diabetes mellitus in rats

OBJECTIVE

To study the effect of nicotinamide (NAA) on prevention and treatment of STZ-induced diabetes mellitus in rats.

MATERIAL AND METHODS

30 Sprague-Dawley rats were randomly divided inot three groups: 20 rats were given NAA 1 g/kg/day intramuscularly (10 rats) or orally (10 rats) as experimental groups and the other 10 rats by normal saline orally as control group. Three days later, all 30 rats received streptozotocin (STZ) 55 mg/kg by intraperitioneal injection and took NAA or normal saline continuously as described above for 14 days. During the study, fasting blood glucose (FBG) was measured before and 72 hours after STZ injection and every 2-3 days later on with Glucometer, 24 hours urinary glucose excretion (UGE) was determined once every 4 days with glucose oxidase, body weight was determined every week, the volume of 24-hour water intake and urine excretion were determined twice and once a week respectively.

RESULTS

Two weeks after STZ injection, FBG and 24 hours UGE of all rats taking NAA were normal or nearly normal, islet function and morphology revealed no significant differences compared with those of the normal, whereas all rats of control group remained hyperglycemic (> 16.6 mmol/L) and markedly higher 24 hours UGE as compared with the normal islets appeared atrophic with decrement of B cell population.

CONCLUSIONS

The results showed that NAA may effectively prevent the occurrence of STZ-induced diabetes mellitus in rats, suggesting that NAA may be an effective agent for prevention and treatment of insulin-dependent diabetes mellitus (IDDM) in prediabetic and early stage of IDDM.