[Experiment study on biological and immunological characteristics of modified DNL of oral squamous cell carcinoma with TNF-alpha gene]

Growing characteristic of gene-transduced and nontransduced DNL in medium of containing rIL-2 was compared,and growing characteristic of gene-transduced DNL in medium of non containing rIL-2 was analyzed.DNA index (DI),cell cycle and immunologic phenotypes of gene-transduced and nontransduced DNL were analyzed with FACS.The results revealed interfered with growth,DL,cell cycle and immunologic phenotypes of DNL,and gene-transduced DNL couldn't growing infinitely.

P53-independent apoptosis: a mechanism of radiation-induced cell death of glioblastoma cells

PURPOSE

Radiation therapy, though routinely used in the treatment of patients with glioblastoma multiforme, is of limited efficacy in extending patients' lives. In this study we investigated the mechanism by which ionizing radiation causes death of glioblastoma cells in the hope of ultimately altering the intrinsic radioresistance of glioblastoma tumors.

METHODS

Radiation survival in vitro was quantitated using linear quadratic and repair-saturation mathematical models. Radiation-induced apoptosis was assayed by fluorescence-activated cell sorter analysis, terminal deoxynucleotide transferase labeling technique, and chromatin morphology. Cellular distribution within the cell cycle was quantitated by dual labeling with propidium iodide and bromodeoxyuridine.

RESULTS

We examined whether in vitro clonogenic radioresistance of glioblastoma would reflect their susceptibility to radiation-induced apoptosis and their ability to undergo a G1 arrest--two cellular functions associated with wild-type p53 expression. We demonstrated that apoptosis contributed to the cytocidal effect of ionizing radiation on glioblastoma cells. The apoptosis observed in glioblastoma cell lines occurred in the absence of wild-type p53 expression. We identified a glioblastoma cell line expressing wild-type p53 and found that it did not exhibit radiation-induced apoptosis but rather underwent a prolonged G1 arrest not observed in any glioblastoma cell line lacking wild-type p53 expression.

CONCLUSION

Apoptosis is an important component of the lethal effect of ionizing radiation on glioblastoma cells and does not require wild-type p53 expression. Glioblastoma expressing wild-type p53 exhibited no apoptosis, even after high radiation doses, but rather underwent a prolonged G1 arrest. The observation of p53-independent apoptosis and p53-dependent Gi arrest in glioblastoma cells have important radiobiologic and clinical implications.

[The PCR amplification, cloning, sequencing, expression in E. coli of gene encoding endoflagella subunit protein (fla B) from Leptospira interrogans serovar lai]

A pair of oligonucleotide primers were designed by ourselves to amplify the endoflagella gene of L. interrogans serovar lai. A fragment about 840 bp was generated with PCR and inserted into plasmid pUC8 after the fragment and pUC8 were digested respectively with Bam HI and Pst I. A recombinant plasmid (designated as pLF1) was obtained. SDS-PAGE analysis indicated that a 33 kd was expressed in E. coli JM103 harboring pLF1 and the expression level of the protein was 11% of total bacterial soluble proteins. Western blot analysis showed that the protein band could be recognized by the antiserum against the endoflagella (Axiall filament) of Leptospira interrogans serovar lai. Nucleotide seguence data showed an open reading frame encoding 282 aminoacids residues, corresponding to a protein of molecular weight 33.6 kd. The G + C content of endoflagella subunit protein gene was 48 mol%. Therefore, the G + C content of the leptospiral fla B Gene is significantly higher than the reported 39 mol% G + C content of leptospiral genome of L.interrogans serovar lai but similar to the G + C of the Treponema pallidum genome. Comparison of the deduced endoflagellar subunit protein (fla B) amino acid sequence with flagellins from other bacteria revealed a high level of identity with the Treponema pallidum fla B proteins. Immunization/protection experiment was performed on the model of BALB/c mice and showed that the survival rate in the group JM103-pLF1 was higher than that in the group JM103-pUC8, but statistically the difference between them was significant (P < 0.05) and pLF1 did not induce significant levels of agglutinating antibodies against L.interrogans serovar lai.

Substrate specificity of the Escherichia coli 4-aminobutyrate carrier encoded by gabP. Uptake and counterflow of structurally diverse molecules

Transport of 4-aminobutyrate into Escherichia coli is catalyzed by gab permease (GabP). Although published studies show that GabP is relatively specific, recognizing the common alpha-amino acids with low affinity, recent work from this laboratory indicates that a number of synthetic compounds are high affinity transport inhibitors (50% inhibition at 5-100 microM). Here we present evidence that many of these structurally heterogeneous compounds not only inhibit transport but also function as alternative GabP substrates (i.e. a set of observations inconsistent with the idea that the core of the GabP transport channel exhibits rigid structural specificity for the native substrate, 4-aminobutyrate.

Study on the column process of adsorption decolorization for monosodium glutamate solution in fluidized beds

The adsorption decolorization of monosodium glutamate solution employed in multiple column fluidized beds in a series is studied. The equilibrium data, the mass transfer kinetics, and fluid flow parameters are determined. A mathematics model taking into account the effects of particle size classification, particle size distribution, external and internal diffusions, and axial mixing in the liquid and solid phases is proposed, and the simulated results are in good agreement with the experimental data.

Hypocalcemia, morbidity, and mortality in end-stage renal disease

BACKGROUND

Hypocalcemia and hyperphosphatemia with secondary hyper-parathyroidism are characteristic of end-stage renal disease (ESRD). Although calcium levels critically affect almost all cellular processes, the impact of chronic hypocalcemia and other abnormalities of calcium-phosphate homeostasis on the prognosis of ESRD patients is unknown.

METHODS

An inception cohort of 433 patients starting ESRD therapy was followed prospectively for an average of 41 months. Serum calcium and other parameters were measured monthly. The mean calcium levels were 9.4 +/- 0.7 mg/dl. 23% of the patients had mean calcium levels < 8.8 mg/dl. After adjusting for baseline age, diabetes mellitus, ischemic heart disease, smoking and cholesterol levels, as well as serial albumin, hemoglobin, mean arterial blood pressure, phosphate and alkaline phosphatase levels, chronic hypocalcemia was strongly associated with mortality (RR 2.10, p = 0.006 for a mean calcium level < 8.8 mg/dl). The association with mortality was similar in hemodialysis (RR 2.10, p = 0.006) and peritoneal dialysis patients (2.67, p = 0.034). Using similar covariate adjustment, chronic hypocalcemia was associated with de novo ischemic heart disease (RR 5.23, p < 0.001), recurrent ischemic heart disease (RR 2.46, p = 0.006), de novo cardiac failure (RR 2.64, p < 0.001), and recurrent cardiac failure (RR 3.30, p < 0.001). Hypocalcemia retained its independent impact on morbidity and mortality when analyzed as a time-dependent covariate.

CONCLUSIONS

Chronic hypocalcemia, a very common, reversible feature of chronic uremia, is independently associated with morbidity and mortality in ESRD patients.

Prolactin release from subpopulations of rat lactotrophs in the presence and absence of dopamine

In this study we examined the effects of dopamine (DA) and its withdrawal on in vitro prolactin (PRL) release from subpopulations of lactotrophs from two regions of the anterior pituitary obtained from untreated ovariectomized (OVX) rats or OVX rats treated with estrogen, progesterone or a combination of the two. Anterior pituitaries were cut horizontally into an inner (dorsal) zone and an outer (ventral) zone. Each of these regions was enzymatically dispersed and the resulting cells were otherwise untreated (unseparated) or centrifuged through a discontinuous Percoll gradient to separate the cells into two subpopulations (light and heavy cells). Each of these types of cells was perifused for 1 h with culture medium containing 1 microM DA followed by medium devoid of DA for 1 h. Prolactin released into the perifusion medium, collected as 5-min fractions, was measured by radioimmunoassay and normalized to the number of lactotrophs in the cellular pools as determined by immunocytochemistry. In the presence of DA, PRL release from unseparated cells of the outer zone was significantly increased by estradiol treatment compared with the release from similar cells from OVX rats. (Differences were considered significant where P < 0.05.) However, no effect of estradiol treatment was observed with unseparated cells of the inner zone or light or heavy cells from either zone. Progesterone had no effect on any cell type when administered alone. However, when progesterone was given following estradiol, PRL release from unseparated cells of the inner zone was increased significantly compared with similar cells from the other steroid-treated groups. Similar significant increases were observed with light and heavy cells of the outer zone, but there was no effect of the combined steroid treatment on light or heavy cells from the inner zone. When DA was withdrawn, prolactin release was significantly increased from all cells except unseparated cells of the outer zone of OVX rat pituitaries. However, when the cells of the outer zone from OVX rats were separated into light and heavy cells, they responded to the withdrawal of DA with significant and equivalent increases in prolactin release. Light cells of the inner zone of pituitaries from OVX rats were more responsive to DA withdrawal than were heavy cells. Estradiol increased the response to the withdrawal of DA by light and heavy cells of the outer zone and heavy cells of the inner zone. Progesterone significantly reversed these effects of estradiol on separated cells. These results suggest that lactotrophs in two regions of rat pituitaries respond differently to dopamine and to its withdrawal, that subpopulations of lactotrophs within these regions also respond differently and that steroids modulate these responses.

Monobromobimane as an affinity label of the xenobiotic binding site of rat glutathione S-transferase 3-3

Monobromobimane (mBBr), besides being a substrate in the presence of glutathione, inactivates rat liver glutathione S-transferase 3-3 at pH 7.5 and 25 degrees C as assayed using 1-chloro-2,4-dinitrobenzene (CDNB). The rate of inactivation is enhanced about 5-fold by S-methylglutathione. Substrate analogs bromosulfophthalein and 2,4-dinitrophenol decrease the rate of inactivation at least 20-fold. Upon incubation for 60 min with 0.25 mM mBBr and S-methylglutathione, the enzyme loses 91% of its activity toward CDNB and incorporates 2.14 mol of reagent/mol of subunit, whereas incubation under the same conditions but with added protectant 2,4-dinitrophenol yields an enzyme that is catalytically active and contains only 0.89 mol of reagent/mol of subunit. mBBR-modified enzyme is fluorescent, and fluorescence energy transfer occurs between intrinsic tryptophan and covalently bound bimane in modified enzyme. Both Tyr115 and Cys114 are modified, but Tyr115 is the initial reaction target and its modification correlates with loss of activity toward CDNB. The fact that the activity toward mBBr is retained by the enzyme after modification suggests that rat isozyme 3-3 has two binding sites for mBBr.

Role of nitric oxide in regulation of long-term pressure-natriuresis relationship in Dahl rats

The aim of this study was to determine the role of nitric oxide (NO) in the development of salt-induced hypertension in the Brookhaven strain of Dahl rats. Six- to seven-week-old conscious salt-sensitive (S) and salt-resistant (R) rats with indwelling arterial and venous catheters received low-, normal-, and high-sodium intakes sequentially over a 16-day period, and L-arginine was infused intravenously at 2 or 4 mg.kg-1.min-1 over this time. The S rats had an impaired NO production as evidenced by a decreased urinary nitrate plus nitrite excretion. The administration of the low or high dose of L-arginine increased the whole body NO production of the S rats to that of the control R rats, and the high dose of L-arginine prevented the shift of long-term pressure-natriuresis relationship, the elevation of arterial pressure, and the increase in salt sensitivity of arterial pressure in the S rats. The sodium and water balances were not different between the age-matched R and S rats. In conclusion, a continuous infusion of L-arginine prevented both the changes in the pressure-natriuresis relationship and the development of salt-induced hypertension in Dahl S rats.

Typing of Staphylococcus epidermidis colonizing in human nares by pulsed-field gel electrophoresis

From the nares of 11 healthy adults, 253 strains of coagulase negative staphylococcus were isolated and 88% of them were identified as Staphylococcus epidermidis using the API STAPH system. Chromosomal DNA fingerprinting of the isolated strains revealed that each person carried multiple types of S. epidermidis in his or her nares. The colonization of the strains was not stable; the types of the isolates changed in the first and the second examinations 5 months apart. The results contrasted with previous findings in which only one strain of S. aureus colonized persistently in the nares of healthy adults.

Typing of Staphylococcus aureus colonising human nasal carriers by pulsed-field gel electrophoresis

Colonisation by Staphylococcus aureus in the nares of 120 outpatients and 63 healthy adults was studied for c. 2 years. Two states of carriage of S. aureus were confirmed: persistent carriage and persistent non-carriage. The states of carriage and non-carriage were quite stable and > 60% of the population of any of the study groups were stable non-carriers. The results of typing the strains isolated from the same individuals at different times with DNA fingerprinting by digestion with SmaI enzyme showed that all the stable carriers were persistently infected with the same strain and that changes in the strain seldom occurred.

Radiation-induced changes in nucleoid halo diameters of aerobic and hypoxic SF-126 human brain tumor cells

Nucleoid halo diameters were measured to assay changes in DNA supercoiling in human brain tumor cell line SF-126 after irradiation under aerobic or hypoxic conditions. In unirradiated aerobic cells, a typical propidium iodide titration curve showed that with increasing concentrations of propidium iodide, the halo diameter increased and then decreased with the unwinding and subsequent rewinding of DNA supercoils. In irradiated cells, the rewinding of DNA supercoils was inhibited, resulting in an increased halo diameter, in a radiation dose-dependent manner. To produce equal increases in halo diameter required about a threefold higher radiation dose in hypoxic cells than in aerobic cells. Quantitatively similar differences in the radiation sensitivities of hypoxic and aerobic cells were demonstrated by a colony-forming efficiency assay. These findings suggest that the nucleoid halo assay may be used as a rapid measure of the inherent radiation sensitivity of human tumors.

[An epidemiological study on the characteristics of smoking behaviors among 910 young workers in Shangqiu City, Henan Province]

This paper dealt with an epidemiological investigation on the smoking behaviors of the young people in Shangqiu city, Henan province. The period of their working history was less than 5 years and their ages younger than 30 years. The interviewees were chosen from the hospitals, middle or professional schools, and large factories in the city. There were 587 males and 339 females included in this sample. Everyone was asked to complete the self-administered questionnaire in the workplace. The total number of sample was 926. The rate of respondence was 98.3%. Of the 926 questionnaires, 910 (98.3%) were identified as qualified. The investigation showed that the overall smoking rate was 32.1%, with male 64.2% and female 1.5%, respectively. The smoking rate of male was approaching the highest rate of adult males in our country, much higher than that of adolescents in school. The rates were parallelly increasing with years of working. About 50% of the young smokers began to be habitual since started their job, especially from the first four years of work. More than 80 percent of the smoking young workers were mild or light smokers, and did not smoke in "Ban Smoking Place". However, the most popular places for smoking were the place where there is a sign at their workplaces. They smoke most often with their colleagues and friends.

p53 controls proliferation of early B lineage cells by a p21 (WAF1/Cip1)-independent pathway

We examined a role of p53 in early B cell development using fetal liver (FL) cells from p53 deficient (-/-) mice. Expression of p53 was detected in early B lineage (pre-B) cells developed in the stromal cell-dependent FL cell culture. Proliferation of the pre-B cells from the p53(-/-) mice was augmented, suggesting that p53 negatively regulates proliferation of pre-B cells. Although p21 (WAF1/Cip1) is a downstream effector of p53 and mediates growth arrest by inhibiting the action of cyclin-dependent kinases, expression of p21 was also induced in the pre-B cells from p53(-/-) mice. These results indicate that expression of the p21 in pre-B cells is independent of p53 and that the regulatory effect of p53 on proliferation of pre-B cells is mediated by a p21-independent pathway.

Type VII collagen specifically binds fibronectin via a unique subdomain within the collagenous triple helix

Type VII collagen is the major component of anchoring fibrils, structures within basement membranes beneath stratified squamous epithelium thought to mediate the adherence of the epidermis to the dermis of human skin. Type VII collagen has affinity for fibronectin. The interaction between type VII collagen and fibronectin is mediated through the collagen-binding domain on the amino terminus of fibronectin. Heretofore, the domain on the type VII collagen molecule that binds to fibronectin was not known. In this study, we mapped the binding site of fibronectin to a specific subdomain of the triple helical collagenous region of type VII collagen, immediately adjacent to the small carboxyl terminal non-collagenous domain. This fibronectin-binding site within the type VII collagen molecule lies between nucleotide residues 615 and 1161.

Neuropeptide Y N-terminal deletion fragments: correlation between solution structure and receptor binding activity at Y1 receptors in rat brain cortex

N alpha-Acetyl (Ac), N-terminal deletion fragments of porcine neuropeptide Y (NPY) have been synthesized and characterized for solution conformation properties by circular dichroism and for receptor binding activity at benextramine-sensitive Y1 binding sites in rat brain cortex. Sequential deletion of Tyr1, Pro2, and Ser3 had no effect on the structural (alpha-helical content of 32.5, 30.6, and 30.7%, respectively, at 1 x 10(-5) M) or aggregation (monomer to dimer transition for N alpha-Ac-NPY3-36 and N alpha-Ac-NPY4-36) properties of NPY. In contrast, deletion of Tyr1 decreased receptor binding activity in rat brain cortex by 4-fold (IC50 = 13.0 nM versus 3.75 nM for NPY), but further deletion of Pro2-Ser3 had no additional detrimental effect on receptor binding activity relative to the desTyr1 analog. Thus, Pro2 and Ser3 do not contribute either to the stability of the NPY tertiary structure nor directly to the receptor-ligand interactions. Additional removal of N-terminal amino acids Lys4-Pro5 decreased the helical content and abolished aggregation to a dimeric form of the resultant analog, results suggesting that the residues around Pro5 are important for formation of NPY's compact, pancreatic polypeptide (PP)-fold structure. This loss in structure also correlated with a further 2-3 fold drop in receptor binding activity. These structure-activity correlations provide evidence for the importance of the PP-fold structure in the activity of NPY at Y1 receptors in rat brain cortex.

Identification of the epitopes on human type VII collagen for monoclonal antibodies LH 7.2 and clone I, 185

Type VII collagen is the major component of anchoring fibrils, structures in human skin that mediate the adherence of the epidermis to the underlying dermis. Dystrophic forms of epidermolysis bullosa, a group of inherited mechanobullous disorders of the skin, are linked to the type VII collagen gene. Several mutations in the recessive form of this inherited disorder have been delineated. In this study, we mapped the epitopes of two commercially available monoclonal antibodies (clone I, 185 and LH 7.2) within the amino-terminal, non-collagenous domain of type VII (anchoring fibril) collagen. The precise localizations of the epitopes for these two monoclonal antibodies which are widely used to diagnose dystrophic epidermolysis bullosa, will be useful for the confirmation of gene mutations at the protein level.

Expression of Ki67 antigen, epidermal growth factor receptor and Epstein-Barr virus-encoded latent membrane protein (LMP1) in nasopharyngeal carcinoma

The expression of Ki67 antigen, epidermal growth factor receptor (EGFR) and the Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP1) in nasopharyngeal carcinoma (NPC) was immunohistochemically determined. In cases with sufficient material western blot analysis was applied to analyse the LMP1 expression. Biopsies from 20 Chinese and 3 Swedish patients with NPC were included in the study. Our results demonstrated a nuclear Ki67 staining, a membrane EGFR staining, and a dot-like cytoplasmic and/or membrane LMP1 staining pattern in tumour cells of NPC. The proportion of Ki67-positive cells correlated with tumour stage. A strong expression of EGFR was frequently seen in patients with tumour stages III and IV and was paralleled by a higher proportion of Ki67-positive cells. The majority of the LMP1-positive cases strongly expressed EGFR and had a higher proportion of Ki67-positive cells, indicating a possible effect of EBV LMP1 on the proliferation of tumour cells in NPC. The increased expression of EGFR and Ki67 in NPC at late tumour stage indicates their possible use in malignancy grading of NPC.

Mechanisms involved in the cardiovascular-renal actions of nitric oxide inhibition

The roles of the sympathetic nervous system, angiotensin II, and arginine vasopressin in the cardiovascular-renal responses to nitric oxide synthesis inhibition were examined in eight conscious dogs equipped with arterial and venous catheters and a nonoccluding bladder catheter. Nitric oxide inhibition was achieved by intravenous infusion of NG-nitro-L-arginine methyl ester (L-NAME) at 37.1 nmol/kg per minute for 140 minutes in the control group. The same dogs, after a 1-week recovery, were pretreated for 2 days with either prazosin for alpha 1 blockade, prazosin plus propranolol for alpha 1 plus beta blockade, L-158,809 for angiotensin receptor blockade, or d(CH2)Tyr(Me)arginine vasopressin for vasopressin-V1 blockade, and the L-NAME infusion was repeated. After 140 minutes of L-NAME infusion into the control group, mean arterial pressure and renal vascular resistance had increased 16% and 71%, and renal blood flow, glomerular filtration rate, urine flow, and urinary sodium excretion had decreased 33%, 16%, 61%, and 64%, respectively. The decrement in renal blood flow and glomerular filtration during L-NAME administration was unaffected by any of the neurohumoral blockers. During V1 blockade L-NAME resulted in only a 3% increase in arterial pressure, attenuation of the renal vascular resistance response, and almost total elimination of the decrease in urine flow. During angiotensin blockade the L-NAME-induced increase in arterial pressure was markedly attenuated, and the decrease in urinary sodium excretion was attenuated in the alpha 1 plus beta blockade group.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of beta-lymphocyte- and NPC-derived EBV-LMP1 gene expression on in vitro growth and differentiation of human epithelial cells

The effect of expression of the Epstein-Barr-virus (EBV) latent membrane protein (LMP1) derived from B-lymphocytes (B) and nasopharyngeal carcinoma (NPC) (C) on the in vitro growth and differentiation of a human keratinocyte line, Rhek-1, was analyzed in clonal growth and in in vitro differentiation assays. In contrast to the polygonal parental cells, the B-LMP1-expressing sublines were spindle-shaped while the C-LMP1-expressing cells were pleomorphic. Both B- and C-LMP1-expressing sublines showed increased proliferation as evidenced by: (1) higher colony-forming efficiency (CFE) and larger colony size at reduced serum levels; (2) an increased number of epithelial cell layers formed in the air-liquid-interface culture system and (3) increased expression of proliferative cell nuclear antigen (PCNA). At low serum concentration, the C-LMP1-expressing sublines formed larger colonies than those expressing B-LMP1. In the air-liquid-interface culture system, both B- and C-LMP1-expressing lines showed reduced epithelial differentiation resulting in reduced stratification and reduced involucrin expression similar to those of the cancer cell line, Siha. The results of the present study indicate that the expression of LMP1 in human keratinocytes is associated with morphological transformation and predisposes these cells to a more neoplastic phenotype. The structural difference between the 2 genes responsible for the functional differences and transforming ability will be pinpointed in further experiments.

Nitric oxide regulates renal hemodynamics and urinary sodium excretion in dogs

The goal of this study was to determine whether nitric oxide has a long-term role in the control of renal hemodynamics and the relation between arterial pressure and urinary sodium excretion. Studies were conducted over a 25-day period in seven conscious dogs equipped with indwelling vascular catheters and an electromagnetic flow probe on the iliac artery. Nitric oxide synthesis was inhibited by continuous intravenous infusion of NG-nitro-L-arginine methyl ester at 37.1 nmol/kg per minute, and the effects of low, normal, and high sodium intakes were determined. Significant nitric oxide synthesis inhibition was evidenced by a decrease in the depressor and flow responses to systemic acetylcholine administration. During the normal sodium intake plus nitro-arginine period, arterial pressure increased to hypertensive levels, averaging 120 +/- 4% of control; renal vascular resistance increased to an average of 134 +/- 8% of control; glomerular filtration rate and renal plasma flow decreased to 83 +/- 3% and 81 +/- 3% of control, respectively; and no changes occurred in filtration fraction, plasma renin activity, plasma concentrations of aldosterone and cortisol, urinary sodium excretion, sodium balance, fractional excretion of sodium, urine volume, and volume balance. Arterial pressure increased further to 130 +/- 3% of control during high salt intake, and sodium balance was achieved at each sodium intake despite the increase in arterial pressure because of a hypertensive shift in the relation between urinary sodium excretion and arterial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Reinfection with Schistosoma japonicum after treatment with praziquantel in Poyang lake region, China

The study on reinfection with Schistosoma japonicum after treatment was carried out in a cohort of subjects in a heavy endemic village of Poyang lake region, China. After mass treatment with praziquantel in non-transmission time, detailed observations of water contact were estimated using the mean area of skin exposed daily. One year after treatment, the prevalence of infection in study subjects was 54.48%, returning to 83% of initial prevalence. The peak prevalence occurred the 11-15 year age class, but intensity of exposure also varies with age and that age group supporting the higher prevalence of reinfection had high levels of exposure. Among groups of subjects with a similar exposure stratum, young subjects under the age of 21 years were more heavily reinfected, while no heavy reinfection was observed in adults (> or = 25 years). These observations suggest that subjects in this area slowly acquire an increasing degree of immunity to lighten the intensity of infection with S. japonicum.

Long-term cardiovascular role of nitric oxide in conscious rats

The goal of this study was to determine the arterial pressure and renal excretory responses to a continuous intravenous infusion of 7.4 nmol/kg per minute of the nitric oxide synthesis inhibitor NG-nitro-L-arginine methyl ester (L-NAME) in conscious rats. Studies were conducted in six groups of Sprague-Dawley rats with indwelling arterial and venous catheters over periods lasting 12 to 26 days. In the first group of rats, L-NAME infusion for 9 days caused a sustained increase in arterial pressure, and on the ninth day arterial pressure was increased 29 mm Hg. Infusion of L-NAME at the higher dose of 37 nmol/kg per minute for 9 days caused no greater increase in arterial pressure than the lower dose. Sodium and volume balances and phenylephrine pressor sensitivity were unchanged during L-NAME administration at 7.4 nmol/kg per minute; plasma renin activity increased 2.5-fold, but the vasodepressor and vasodilator responses to acetylcholine and bradykinin were unchanged. Arterial pressure remained significantly increased 7 days after L-NAME was stopped, but in another group of rats, intravenous L-arginine infusion caused arterial pressure to return to control within 1 day. This same dose of L-arginine was administered for 7 days intravenously, and neither arterial pressure nor sodium balance changed. In other groups of rats, L-arginine was administered in conjunction with L-NAME; this prevented any change in arterial pressure, whereas D-arginine did not. In conclusion, the data suggest that continuous intravenous infusion of L-NAME causes sustained increases in arterial pressure in conscious rats without any sodium or water retention. The hypertension is accompanied by increases in plasma renin activity and can be prevented with intravenous L-arginine administration.

[A new natural focus of scrub typhus found in Hunchun]

From May to June 1992, Apodemus agrarius and Apodemus speciosus were captured in Hunchun, Jilin Province. Four strains of Rickettsia tsutsugamushi were isolated from viscera of rats and trombiculid mites. At the same time, the antibody against Rickettsia tsutsugamushi was assayed in the sera of the local people and the wild rats. The positive rates were 15.2% and 16.4%, respectively. The above results showed that a natural focus of scrub typhus exists in Hunchun area.

Hippocampal synaptic pathology in patients with temporal lobe epilepsy

Immunostaining of synaptic terminals was studied in the hippocampus of 26 patients who had surgical resections for intractable temporal lobe epilepsy. Two monoclonal antibodies (EP10 and SP12) reactive with distinct synaptic antigens were used on paraffin-embedded tissues. The results indicated qualitative reductions on synaptic terminals in CA4 and other regions where cell loss is reported. The inner molecular layer of the dentate gyrus was observed to have increased synaptic immunostaining. Synaptic terminal loss in CA4 and redistribution in the molecular layer were most frequent in cases with hippocampal sclerosis. However, both forms of synaptic pathology were also noted in most cases where the pathological findings were classified as indefinite, and in some cases associated with mass lesions of the temporal lobe. These results support the importance of neuronal loss and synaptic reorganization as possible mechanisms of illness in epilepsy. They also indicate that synaptic immunostaining may be a useful adjunct to routine neuropathological diagnostic techniques.

Activation of keratin 19 gene expression by a 3' enhancer containing an AP1 site

We previously reported that the human keratin 19 (K19) gene was expressed in nonkeratinizing oral epithelial subtypes, and that the steady state K19 mRNA levels in different normal epithelial subtypes correlated with the levels of the retinoic acid receptor (RAR) beta-mRNA (Hu, L., Crowe, D. L., Rheinwald, J. G., Chambon, P., and Gudas, L. J. (1991) Cancer Res. 51, 3972-3981). To elucidate the mechanisms by which the K19 gene is differentially expressed in various epithelial subtypes, we isolated phage containing human K19 genomic DNA from a human placental library. Through transient transfection assays with various K19/CAT constructs that contain different portions of K19 genomic DNA, an enhancer sequence has been identified in the K19 3'-flanking region. In normal human epithelial cell strains, the activity of this enhancer correlates with K19 mRNA abundance. This enhancer activates both the K19 and TK basal promoters in HeLa cells. A high level of K19/CAT fusion mRNA was detected when this K19 3' enhancer sequence was present at the 3' end of the fusion gene whereas no K19/CAT fusion transcript was detected if this 3' K19 enhancer sequence was absent, suggesting that the 3' K19 enhancer is crucial for the positive regulation of K19 expression. Deletion analysis has permitted the localization of the enhancer to a 19-base pair sequence which contains an AP1 binding site (AGTCATCT). Point mutations within this AP1 site completely abolished K19 enhancer activity in HeLa cells. Co-transfections of a c-jun expression vector with K19/CAT reporter constructs demonstrated that c-jun was able to activate the K19 promoter via the 3' K19 enhancer. Collectively, these data indicate that a cis-acting AP1 element and its associated trans-acting effector proteins regulate expression of lineage-specific genes in epithelial cells.

Neuropeptide Y acylation chemistry in aqueous solution: significance to synthesis of a peptide-based photoaffinity label

Treatment of neuropeptide Y (NPY, 1) for 20 hr with a 20 equivalent excess of N-propionyl succinimide (2) in 10 mM phosphate buffer, pH 6.0, yields NPY and N alpha-propionyl-NPY (3) as major products, and at pH 7.5 the major product is N alpha, N epsilon-dipropionyl-NPY. However, acylation of NPY with one equivalent of N-(5-azido-2-nitrobenzolyloxy)-succinimide (5) is more rapid, yielding N alpha-(5-azido-2-nitrobenzoyl)-NPY (6) in 70% conversion yield after only 5 min. Thus, in spite of its increased reactivity, the N-hydroxysuccinimide active ester shows enhanced alpha- vs. epsilon-NH2 selectivity relative to 2. The activities of 3, 4, and 6 as reversible, competitive ligands at rat brain NPY binding sites and of 6 as an irreversible photoaffinity label are reported.

Distribution of lactotroph subpopulations in different regions of the rat pituitary

In this study, we examined the distribution of lactotrophs in different regions of pituitaries of ovariectomized (OVX) rats either untreated or treated with estradiol, progesterone or a combination of estradiol and progesterone. Anterior pituitaries were cut into inner and outer zones. Each of these regions was enzymatically dispersed and the resulting cells subjected to density sedimentation through a discontinuous Percoll gradient. The light and heavy cell subpopulations obtained were compared with cells not subjected to Percoll (unseparated cells). Cell numbers were determined and prolactin positive cells were assessed by immunocytochemistry. In OVX rats, the percentage of lactotrophs in the unseparated cell fraction of the outer zone was significantly (P < 0.05) lower than that in the inner zone. Estradiol increased the percentage of PRL cells in all cell populations, but the effect on inner zone light cells was significantly less than on any other type of cells. Progesterone given alone did not affect the percentage of lactotrophs in pituitary compared to untreated OVX rats nor did it alter the effects of estradiol. When the number of lactotrophs was calculated, the unseparated cells of inner and outer zone were equivalent except in the untreated OVX group where there was a significantly greater number of lactotrophs in the outer zone. In untreated OVX rats there was an equal distribution of lactotrophs between light and heavy cells in both inner and outer zones. Estradiol significantly increased the number of PRL cells in both zones and the effect was greater in the heavy cell fractions especially in the outer zone. In contrast, progesterone decreased the number of PRL positive cells in both zones and across cell types, but this effect was most pronounced in the outer zone. Progesterone also decreased the total pituitary cell number and this effect was greater than could be accounted for by the decrease in lactotroph numbers. We conclude that, except in untreated OVX rats, the numbers of lactotrophs in inner and outer zones are similar. The results also indicate that estradiol and progesterone can significantly alter the proportion and/or numbers of PRL positive cells within pituitary zones and may also affect cells that are not identified as PRL positive.

Individualizing drug dosage regimens: roles of population pharmacokinetic and dynamic models, Bayesian fitting, and adaptive control

The role of population pharmacokinetic modeling is to store experience with drug behavior. The behavior of the model is then correlated with the clinical behavior of the patients studied, permitting selection of a specific serum level therapeutic goal that is based on each individual patient's need for the drug and on the risk of adverse reactions, both of which must be considered. A dosage regimen is then computed to achieve that goal with maximum precision. The patient should not run a greater risk of toxicity than is justified, and should obtain the maximum possible benefit within the acceptable risk. The regimen is given and the patient monitored.

[The distribution of normal oral flora in 49 healthy children and juvenile]

The frequencies and proportions of predominant cultiv ableoral bacteria associated with 49 healthy children and juvenile (6-25 yr old) were studied. A total of 72 bacterial species belonging to 28 genus were detected in 195 samples of saliva, fissure plaque, supragingival plaque, and subgingival plaque. The predominant bacteria were Oral streptococci, Neisseria, Actinomyces, Capnocytophaga, Bacteroides and Fusobacterium in the normal oral cavity of healthy children and juvenile. There were differences in the distribution of the predominant flora, e.g. Fusobacterium and Bacteroides had higher incidence and proportion in the subgingival plaque than in the fissure plaque.

The contribution of helical potential to the in vitro receptor binding activity of a neuropeptide Y N-terminal deletion fragment

In its dimeric form neuropeptide Y (NPY) folds into a compact structure in which the antiparallel oriented proline and alpha-helices apparently associate to form a primitive hydrophobic core. To investigate the contribution of helical stability to the receptor binding activity of NPY and its N-terminal deletion fragments, we synthesized and studied the solution conformational properties and in vitro activities of NPY, N alpha-acetyl-NPY2-36, NPY15-36, N alpha-propionyl-NPY15-36, and N alpha-succinyl-NPY15-36. NPY15-36 is significantly less helical than both NPY and N alpha-acetyl-NPY2-36, and this decreased helical potential is attributed to the absence of the intramolecular stabilizing interaction afforded by the proline helix in the latter analogues. However, in accord with the helix dipole model, the helical potential of NPY15-36 is significantly increased by N-terminal succinylation, whereas propionylation has no effect. In addition to an increase in helical potential, N alpha-succinyl-NPY15-36 is 2.5 and 4.6 times more active than NPY15-36 and N alpha-propionyl-NPY15-36, respectively, and is equipotent with N alpha-acetyl-NPY2-36 in displacing 1 nM [3H]-NPY from specific binding sites in rat brain membranes. The demonstration of a positive correlation between % alpha-helix content and in vitro binding activity suggests that the helical potential of N-terminal NPY deletion fragments contributes to their in vitro activity in the rat brain, and that a second role of the proline helix might be to stabilize the receptor-active conformation of the NPY alpha-helix.

Cardiovascular responses to long-term blockade of nitric oxide synthesis

The goal of this study was to determine if there is a basal release of nitric oxide that affects long-term arterial pressure regulation in dogs. Studies were conducted over a 23-day period in eight conscious dogs with indwelling catheters. Nitric oxide synthesis was blocked by continuous intravenous infusion of nitro-L-arginine-methyl ester at 37.1 nmol/kg per minute for 11 days. Arterial pressure increased to 120 +/- 4% of control on the first day, decreased for a few days, and then increased to a maximum value of 122 +/- 6% of control on day 7. Bradycardia was sustained throughout the entire nitro-arginine period. Blockade of nitric oxide synthesis was evidenced by attenuated pressure and flow responses to systemic acetylcholine infusion. The pressor response to phenylephrine was increased for only 1 day, and the hypotensive effects of nitroprusside were enhanced. Also, the variability of arterial pressure was significantly increased during nitro-arginine. Sodium and water balances were positive the first day of nitro-arginine infusion but were unchanged for the entire nitro-arginine period. In conclusion, the data suggest that blockade of the basal release of nitric oxide in dogs causes an increase in the long-term level of arterial pressure without any sustained sodium or water retention.

Role of nitric oxide in long-term angiotensin II-induced renal vasoconstriction

In vitro studies have indicated that nitric oxide may play an important role in modulating the renal vascular actions of angiotensin II (Ang II). However, the physiological importance of this interaction in the long-term regulation of renal hemodynamics is unknown. Therefore, the goal of this study was to determine if long-term Ang II-induced renal vasoconstriction was potentiated by nitric oxide synthesis inhibition. The intrarenal effects of Ang II were examined in eight unilaterally nephrectomized, conscious dogs before and after systemic inhibition of nitric oxide synthesis. Ang II infusion into the renal artery at 0.5 ng/kg per minute resulted in decreases in renal plasma flow of 15% and 9% after 3 and 5 days, respectively. During this time, glomerular filtration rate decreased 12% after 3 days of angiotensin but was not significantly changed after 5 days. After 4 days of recovery from Ang II, nitric oxide synthesis was inhibited with intravenous NG-nitro-L-arginine-methyl ester (L-NAME) at 10 micrograms/kg per minute for 5 days, and this caused a significant decrease in renal plasma flow but no change in glomerular filtration rate. Infusion of Ang II into L-NAME-pretreated dogs for an additional 5 days further decreased renal plasma flow and glomerular filtration 14% and 11%, respectively. However, the effects of Ang II and L-NAME on renal plasma flow were only additive on days 3 and 5 of this period, and the effects on glomerular filtration were additive on day 3 but were potentiated on day 5.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of galactose regimen on glomerular heparan sulfate synthesis and albumin excretion in diabetic rats

Decreased glomerular heparan sulfate synthesis could account for the increased albuminuria observed in experimental diabetes. A similar albuminuria has been observed in galactose-fed animals. To test whether heparan sulfate synthesis is also decreased in galactosemic animals we measured the heparan sulfate synthesis in isolated renal glomeruli from streptozotocin diabetic and normal rats fed regular diets or 30% galactose diets for 11-12 weeks. Albumin excretion and glomerular heparan sulfate synthesis were determined at the time of sacrifice. As predicted by this hypothesis glomerular heparan sulfate synthesis was significantly lower in the diabetic group than in normals given regular diets (309 +/- 23 vs 487 +/- 56 dpm/mg glomerular wt.; P < 0.01), and albumin excretion greater in these diabetics than in the normals (20 +/- 4.3 vs 2.0 +/- 0.7 mg/24 hr; P < 0.002). Albumin excretion and glomerular heparan sulfate synthesis were also consistent with the hypothesis, but unpredictably reversed, in the galactose-fed diabetic group. Glomerular heparan sulfate synthesis was significantly increased in this group (713 +/- 67 dpm/mg glomerular wt.) and albumin excretion decreased (10.7 +/- 3.6 mg/24 hr) compared to the diabetic on regular diet. Some possible explanations are discussed, but the galactose effect described here remains phenomenological.

Human synaptic proteins with a heterogeneous distribution in cerebellum and visual cortex

Synaptic pathology is likely to be an important feature of a number of neuropsychiatric illnesses. An antibody called EP10 was used previously to demonstrate a regional reduction in a 38 kDa synaptophysin-like protein in Alzheimer's disease. The SP antibodies were developed for further study of this and other synaptic proteins in human brain. Human brain proteins immunoprecipitated with EP10 were used as the immunogen. Hybridoma screening was carried out with a sequential ELISA-immunocytochemical approach. Sixteen antibodies were obtained, the antigens clustered into five groups. Five antibodies were reactive with a 38 kDa synaptophysin-like protein. Another two antibodies were reactive with a 16 kDa antigen which may be synaptobrevin. Immunocytochemical studies indicated these two antigens appeared to be co-localized in human brain. Four antibodies were reactive with a distinct, 34-36 kDa antigen. In the cerebellum, this antigen was restricted to terminals in the molecular layer, putatively in the parallel fibre synapses. Two antibodies were reactive with a 26-27 kDa antigen. In the cerebellum, this antigen localized to a subset of terminals which included the axo-axonal contacts of the Basket and Purkinje cells. The final group of three antibodies detected a complex group of 38 kDa. 40 kDa and higher molecular weight antigens. The results suggest that heterogeneity among synapses can be defined through antibodies directed against distinct proteins. The SP antibodies may be useful probes for studies of human synaptic proteins, and for studies of pathological conditions which disrupt these molecules.

[Study on analysis of peimisine in bulbus fritillariae by HPLC]

A new method for the determination of peimisine in bulbus Fritillariae by ion-pair HPLC has been developed. The chromatographic system consists of ODS column and mobile phase of methanol--water (69:31) containing 7.5 mmol/L of SDS (pH 4.5 +/- 0.1). Twelve samples of different species in the family of Fritillaria have been analyzed by this method. The results show that all samples contain peimisine and the contents of peimisine are correlative to those of total alkaloids.

Benextramine-neuropeptide Y (NPY) binding site interactions: characterization of 3H-NPY binding site heterogeneity in rat brain

Pre-incubation of rat brain membranes with 200 microM benextramine followed by extensive dilution and washing to remove unbound ligand reduced Bmax for N-[propionyl-3H]-NPY (3H-NPY) specific binding by 61% relative to control membranes treated identically but in the absence of benextramine. When rat brain membranes were co-incubated with 3H-NPY and 57 microM benextramine, there was a significant shift to the right; the apparent Kd for 3H-NPY binding increased two-fold relative to control membranes. These data are consistent with the hypothesis that benextramine is a competitive and irreversible ligand for a population (60-65%) of rat brain NPY binding sites. 'Paired tube' assays were then used to determine the selectivity of these benextramine-sensitive and insensitive 3H-NPY binding site populations. PYY, NPY and NPY13-36 each displaced 100% of 3H-NPY from rat brain membrane binding sites both in the absence and presence of 1 mM benextramine. In contrast, [Leu31,Pro34]NPY displayed the same binding site selectivity as benextramine in displacing 65% of 3H-NPY from specific binding sites on untreated rat brain membranes, and it failed to displace 3H-NPY from membranes treated with 1 mM benextramine. Thus the selectivity of the benextramine-insensitive 3H-NPY binding site population--PYY > = NPY > NPY13-36 >> [Leu31,Pro34]NPY--is characteristic of a Y2-like NPY binding site population, while the benextramine-sensitive 3H-NPY binding sites appear to be a Y1-like binding site population.

[Studies of outer membrane protein profiles by SDS-PAGE for Campylobacter jejuni in an epidemiological investigation]

The characteristics of outer membrane protein profiles of 41 strains of Campylobacter jejuni from various sources by SDS-PAGE was studied. Seven and nine OMP patterns were differentiated respectively by the presence or absence of six outer membrane protein bands and by the number and size of the molecular weight of the major protein bands. Comparing the OMP patterns of the strains from human with those from animals, the authors inferred that chickens and other animals might be one of the sources for the human infection of Campylobacter jejuni in this district. A comparison between the OMP patterns of the strains from diarrheic children and those from healthy carriers suggested that the pathogenesis of Campylobacter jejuni be possibly associated with the outer membrane proteins. Using the techniques, the authors studied the infection of Campylobacter jejuni in a nursery. The result showed the infection was sporadic and of multi-sources, as evidenced by the multi-patterns of the outer membrane protein profiles. It also indicates that the person-to-person transmission plays a significant role in the infection of Campylobacter jejuni.

Transcriptional regulation of the human placental-like alkaline phosphatase gene and mechanisms involved in its induction by sodium butyrate

The human alkaline phosphatases constitute a multigene family with at least four members. Placental-like alkaline phosphatase (PLAP) is of particular interest because it is frequently present in tumors, where it serves as a marker of malignant transformation. Moreover, its expression is highly inducible by differentiating agents such as sodium butyrate. In the present study we have examined the PLAP gene promoter in order to better understand the mechanisms involved in its expression and induction. The PLAP promoters from four colon cancer cell lines with widely varied butyrate-inducible alkaline phosphatase activity were thermally amplified and sequenced. The overall sequence similarity of this region was found to be 99% between cell lines; thus, sequence variation of the promoter does not appear to account for the differential expression of this marker. We therefore analyzed the activity of the LS174T cell PLAP promoter using transient transfection experiments. Here, the 5'-flanking region of the gene was found to have positive regulatory elements in nucleotides -1 to -170 and -363 to -512 (relative to the start of transcription). A negative control element was also found to be present in the region between nucleotides -170 and -363. Mobility shift electrophoresis indicated that a nuclear factor bound to the promoter between bases -182 and -341. Furthermore, the activity of the PLAP promoter was found to be inducible by sodium butyrate. In contrast, the closely related placental alkaline phosphatase gene promoter exhibited almost no response to this agent. These results confirm that the activity of the PLAP promoter is stimulated by sodium butyrate and delineate regions that control this induction process.

Bovine tracheal serous cell secretion: role of cAMP and cAMP-dependent protein kinase

The role of adenosine 3',5'-cyclic monophosphate (cAMP) and protein phosphorylation during beta-adrenergic receptor stimulation of bovine tracheal gland serous cells was investigated in vitro. Isoproterenol, a beta-adrenergic agonist, increased the secretion of 35S-labeled molecules. Intracellular cAMP levels were increased within 1 min after stimulation of bovine tracheal gland serous cells with isoproterenol. The dose-response relationship for isoproterenol-stimulated generation of cAMP correlated with the dose-response relationship for isoproterenol-stimulated secretion of 35S-labeled molecules. The phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine potentiated both isoproterenol-evoked secretion of 35S-labeled molecules and the production of intracellular cAMP, and the beta-adrenergic receptor antagonist propranolol completely blocked both effects. The secretory response of the cells to isoproterenol could be mimicked by the cAMP analogues 8-bromoadenosine 3',5'-cyclic monophosphate and dibutyryl adenosine 3',5'-cyclic monophosphate. Activity of cAMP-dependent kinase was measured in soluble and particulate cell extracts. cAMP effected the state of phosphorylation of proteins associated with the soluble but not the particulate fraction. These studies are consistent with the hypothesis that beta-adrenergic stimulation of secretion from bovine tracheal gland serous cells occurs via a cAMP-mediated pathway and that one of the molecular events in this pathway is cAMP-dependent protein phosphorylation.

[The effect of gu chi wan on enzyme histochemistry changes in diabetic rats with experimental periodontal disease]

This study observed the effect of Gu Chi Wan on the enzyme histochemistry changes of diabetic rats with experimental periodontal disease. The results indicate that the experimental group has not the decrease of oxidase-reductase and alkaline phosphatase as seen in control group and demonstrate the protective effect of Gu Chi Wan perhaps acts through regulating metabolism of periodontium of rats with experimental periodontal disease, and then improving the immune response of the host.

Prophylactic and therapeutic effects of acupuncture on simple obesity complicated by cardiovascular diseases

In order to understand the prophylactic-therapeutic effects of acupuncture and moxibustion in simple obesity complicated by cardiovascular diseases, we have observed in 102 cases the changes of pathogenetic and hazardous factors and the regulating function of vegetative nerves on cardiovascular activities. The results showed that the therapeutic effect of acupuncture and moxibustion was good with a total effective rate of 88.24%. At the same time, acupuncture and moxibustion were found to have a benign conversion effect on the loin hip ratio (the pathogenetic factor), the arteriosclerotic index (the hazardous factor), and the vegetative nerve function of regulating the heart and blood vessels (the equilibrium indices of the vegetative nervous system). All this suggests that acupuncture is a treatment of choice for obesity and an important method of preventing and treating complicating cardiovascular diseases.