Three-dimensional pharmacophore hypotheses for the locust neuronal octopamine receptor (OAR3). Part 2: agonists

Three-dimensional pharmacophore hypotheses were built from a set of 43 agonists against octopamine receptor class 3 (OAR3) in locust nervous tissue. Among the 10 chemical-featured models generated by program Catalyst/Hypo, a hypothesis including hydrogen-bond acceptor (HBA), hydrophobic (Hp), and hydrophobic aliphatic (HpA1) features was considered to be important and predictive in evaluating OAR3 agonists. While the ideal and null hypotheses had a cost of 156.40 and 239.20, respectively, the 10 resulting hypotheses possessed costs from 169.89 to 175.81. The best hypothesis that was confirmed to have a 95% chance of true correlation yielded a low RMS of 0.757 and high regression r of 0.933. Active agonists mapped well onto all the features of the hypothesis such as HBA, Hp, and HpA1. On the other hand, inactive compounds were shown to be difficult to achieve the energetically favorable conformation which is found in the active molecules in order to fit the 3-D chemical feature pharmacophore models.

Three-dimensional molecular field analyses of octopaminergic agonists and antagonists for the locust neuronal octopamine receptor class 3

The quantitative structure-activity relationship (QSAR) of a set of 70 octopaminergic agonists and 20 antagonists against octopamine receptor class 3 (OAR3) in locust nervous tissue was analyzed by molecular field analysis (MFA). MFA of these compounds evaluated effectively the energy between a probe and a molecular model at a series of points defined by a rectangular grid. Contour surfaces for the molecular fields are presented. These results provide useful information in the characterization and differentiation of octopaminergic receptor types and subtypes.

[Clinical and experimental study of jianruling in treating hyperplasia of mammary gland]

OBJECTIVE

To observe the therapeutic effect of Jianruling (JRL) on hyperplasia of mammary gland (HMG) and to explore its mechanism in regulating sex hormones.

METHODS

Clinical changes of HMG were observed and serum sex hormones measured before and after JRL treatment. In experimental study, the effect of JRL was estimated by using electron microscope, pathologic and radioimmunoassay.

RESULTS

JRL could not only cure HMG, but also regulate the sex hormone secretion both in HMG patients and in rats. Clinical study showed that the clinical cure rate was 72.5%, and the total effective rate was 90.8%, it demonstrated a significant difference in comparing with the control group, P < 0.01. The estradiol and prolactin levels of patients lowered significantly after JRL treatment, P < 0.05, while progestogen and testosterone increased significantly, P < 0.05, but no significantly change of follicle-stimulating hormone and luteinizing hormone was found. JRL showed marked effect in treating and preventing experimental HMG in rats, it could modulate the secretive function of sex hormone, and improve the construction of mammary gland.

CONCLUSION

JRL has significant effect in treating HMG, it can adjust the endogenous sex hormone level, delay the development of chronic cystic hyperplasia of mammary gland.

[Analysis of T cell subgroup in children with allergic rhinitis]

OBJECTIVE

To observe the different distribution of T cell in peripheral blood between normal children and children with allergic rhinitis.

METHOD

We use the indirect immunofluorescence to make a statistical analysis randomly in 16 children with allergic rhinitis and 20 in control group.

RESULT

CD3, CD4, CD8 in peripheral blood of patients are a lot less than those in normal children.

CONCLUSION

The change of T cell subgroup's distribution is an important process of immune mechanism disturbance and can be used as a monitoring standard in allergic diseases.

[Heat strain for personnel wearing three levels of protective ensembles at moderate and heavy workloads]

The effects of individual protective ensembles and workloads on personnel's physiological heat strain were experienced by personnel in a hot environment (35 degrees C, 55% relative humidity). Six young males performed treadmill tests at both moderate (ML: 1.11 m/s, 5% grade) and heavy (HL: 1.34 m/s, 5% grade) workloads. They wore three levels of protective ensembles: protective mask only (PM), protective clothing only (PC), and full protective ensembles (FP). Tests lasted 60 min and 45 min, respectively, for ML and HL. Physiological measurements included heart rate (HR), rectal (Tre) and skin (Tsk) temperature, sweat rate (SR), and sweat evaporative rate (ER). Differences between the ensembles and the workloads were significant for HR responses. The increase rate in Tre and Tsk, and SR, ER were significantly reduced from PM and PC to FP condition during ML and Hl tests. The sweat evaporation restriction of ensembles and the increase of heat production from exercise are the main factors of enhancing the heat strain.

[Correlations between factors and intraocular pressure following photorefractive keratectomy]

OBJECTIVE

To evaluate the factors related to intraocular pressure (IOP) after excimer laser photorefractive keratectomy (PRK).

METHODS

86 cases 150 eyes of myopia followed over six months after PRK were studied with noncontact tonometer (NCT).

RESULT

After PRK, a decrease in the IOP was observed. Post-operatively, the IOP reading at 1st month was the highest. The reduction of IOP may be related to the decrease in corneal thickness and corneal curvature (r = 0.361, P < 0.01; r = 0.188, P < 0.05). Regression equation for IOP drop (kPa) = - 0.059 - 0.038X(1) + 0.009X(2)[X(1) = ablation depth (microm), X(2) = decrease in corneal curvature (D)].

CONCLUSION

IOP readings after PRK are influenced by corneal thickness, corneal curvature and eye drug times.

[The treatment of rat fulminant hepatic failure by auxiliary partial heterotopic liver transplantation: experimental study]

OBJECTIVE

To confirm the effect of auxiliary partial heterotopic liver transplantation (APHLT) in the treatment of fulminant hepatic failure (FHF).

METHOD

On 30 rat models of FHF, 62% of partial liver grafts were implanted below the host residual liver with 28 successful operations. The survival rate, biochemical test for liver function, (99m)Tc-HIDA liver scintigraphy and pathological changes of the grafts and host livers were studied.

RESULT

The survival rate in 48 hours was 71.4% compared with 0% in 15 FHF animals. 14 days after the operation, the host liver regenerated obviously and the liver function recovered while the graft shrank gradually. 30 days later, the graft became fibrosis completely.

CONCLUSION

Depending on the temporary function support of the graft, the native residual liver could regenerate and restore its function while the graft tended to atrophy.

Quantitative structure-activity studies of octopaminergic agonists and antagonists against nervous system of Locusta migratoria

The quantitative structure activity relationship (QSAR) of octopaminergic agonists and antagonists against the thoracic nerve cord of the migratory locust, Locusta migratoria L., was analyzed using physicochemical parameters and regression analysis. The hydrophobic effect, dipole moment, and shape index were important in terms of Ki: the more hydrophobic, the greater dipole moment, and the smaller shape index of the molecules, the greater the activity. A receptor surface model (RSM) was generated using some subset of the most active structures. Three-dimensional energetics descriptors were calculated from RSM/ligand interaction and these three-dimensional descriptors were used in QSAR analysis. This data set was studied further using molecular shape analysis.

[Expression of nitric oxide synthase in squamous cell carcinoma of tongue and its prognosis]

OBJECTIVE

To study the expression of nitric oxide synthase (NOS) in squamous cell carcinoma of tongue and its prognosis.

METHODS

The NOSI, NOSII and NOSIII of 55 cases of squamous cell carcinoma of tongue were detected by immunohistochemistry.

RESULTS

The expressive rates of NOSI, NOSII and NOSIII were 30.9%, 40.0% and 38.2% respectively. There were significant differences between the patients with and without neck nodal metastasis, and between the patients survival more than 5 years and less than 5 years (P < 0.01), There were differences between G1, G2 and G3 and the clinical stages in NOSII (P < 0.05).

CONCLUSION

The expression of the NOSI, NOSII and NOSIII in squamous cell carcinoma of tongue is raleted to its prognosis and the NOSII plays a more important role in growth, differentiation, metastatic capability and prognosis of the tumor.

[Effect of interleukin-1, interleukin-6 on the intercellular communication of rat thyroid FRTL-5 cells]

We observed the effects of thyrotropin (TSH), interleukin (IL)-1 beta and IL-6 on the intercellular communication of FRTL-5 cells with fluorenscence redistribution after photobleaching (FRAP) analysis. FRTL-5 cells were cultured and exposed to the different concentrations of TSH, IL-1 beta and IL-6 for 12 hours. The mean fluorescence recovery rate (MFRR, %/min) of the cells labelled with carboxyfluocein diacetate (CFDA) after photobleaching was measured with laser scanning cytometry. The MFRR (%/min) of the cells after exposure to TSH was 0.445 +/- 0.033 at the control group, 0.679 +/- 0.054 at the group of 0.1 U/L, 0.950 +/- 0.073 at the group of 1 U/L, and 0.799 +/- 0.082 at the group of 5 U/L, respectively (F = 11.44, P < 0.01). The indicated that TSH could enhance the intercellular communication of FRTL-5 cells. The MFRR after exposure to IL-1 beta was 0.564 +/- 0.032 at the control group, 0.485 +/- 0.042 at the group of 10(3) U/L, 0.445 +/- 0.043 at the group of 10(4) U/L and 0.405 +/- 0.029 at the group of 10(5) U/L, respectively (F = 3.58, P < 0.01). The suggested that IL-1 beta could inhibite the intercellular communication of FRTL-5 cells. IL-6 had no obvious effect on the intercellular communication of FRTL-5 cells.

[The preparing of Bacillus penetrans preparation and their controlling to root-knot nematodes]

In order to make use of B. penetrans the preparation of these bacteria was prepared successfully. Each gram of the specimen contains more than 3.1 x 10(8) spores according to determination by bloodcount plate. The method of its production are: First, infect the larvae of root-knot nematodes with the spores of B. penetrans. Second, inoculate infectable plants with the infected larvae. Third, beat the root-systems of inoculated plants after adding some water. The flowed liquid from a bronze sieve was mixed with the clear water, filtered, precipitated, air-dried under 5-10 degrees C, and grinded into fine powder, When these powder was added into the water which contained the larvae of root-knot nematodes, the spores of B. penetrans adhered to the cuticles of these larvae in 24 h. The pot experiments of tomato, chilli and cockscomb showed that the galls, egg-sacs, females, males and all-stages of larvae produced by the plant inoculated with the larvae infected with B. penetrans are about 75%-80% less than that without these bacteria. Thus it can be seen that the spores of B. penetrans can depress the populations of root-knot nematodes obviously. Therefore, it is a promising preparation for biological control.

Quantitative structure-activity studies of octopaminergic 2-(arylimino)thiazolidines and oxazolidines against the nervous system of Periplaneta americana L

The quantitative structure-activity relationship (QSAR) of octopaminergic 2-(arylimino)thiazolidines (AITs) and 2-(arylimino)oxazolidines (AIOs) against the thoracic nerve cord of the American cockroach, Periplaneta americana L., was analysed using reported physicochemical parameters and regression analysis. The more electron-donating, the less bulky at m-position, and the more hydrophobic the substituent, the greater the activity. The plots of observed log Vmax values against calculated log Vmax values having substituents on the m-position deviated downwards from those of compounds having substituents at the 0- and/or p-positions. The more hydrophobic and the more electron-withdrawing the substituent, the greater the activity. AIO with a 2, 3, 4-trichlorophenyl group (58) was more active than its thiazolidine derivative, 2-(2,3,4-trichlorophenylimino)thiazolidine (38) in terms of Vmax:Vmax of 58 was 30% relative to octopamine (OA), whereas that of 38 has been 9% relative to OA, respectively. Superimposition of energy-minimized OA and 58 revealed structural and conformational similarities that might account for the high activity of 58.

[24 hours ambulatory blood pressure in impaired glucose tolerance patients]

We investigated the change of 24 hours ambulatory blood pressure (ABPM) in impaired glucose tolerance (IGT) patients. 40 IGT patients were divided into two group: normotension and hypertension groups. Each group was matched with normal glucose tolerance (NGT) and non-insulin-dependent diabetes mellitus (NIDDM) group. All the patients were subjected to ABPM and biochemical index examination. The profile of ABPM in IGT patients with or without hypertension was investigated. The change of the 24 hours blood pressure in both normotensive and hypertensive IGT patients was similar with NGT, but there was a tendency that night blood pressure was increased and nocturnal blood pressure was decreased in IGT. The change of ABPM in those with abnormal circadian rhythm was elevated night blood pressure.

Adaptive modification of treatment planning to minimize the deleterious effects of treatment setup errors

PURPOSE

Using daily setup variation measured from an electronic portal imaging device (EPID), radiation treatment of the individual patient can be adaptively reoptimized during the course of therapy. In this study, daily portal images were retrospectively examined to: (a) determine the number of initial days of portal imaging required to give adequate prediction of the systematic and random setup errors; and (b) explore the potential of using the prediction as feedback to reoptimize the individual treatment part-way through the treatment course.

METHODS AND MATERIALS

Daily portal images of 64 cancer patients, whose treatment position was not adjusted during the course of treatment, were obtained from two independent clinics with similar setup procedures. Systematic and random setup errors for each patient were predicted using different numbers of initial portal measurements. The statistical confidence of the predictions was tested to determine the number of daily portal measurements needed to give reasonable predictions. Two treatment processes were simulated to examine the potential opportunity for setup margin reduction and dose escalation. The first process mimicked a conventional treatment. A constant margin was assigned to each treatment field to compensate for the average setup error of the patient population. A treatment dose was then prescribed with reference to a fixed normal tissue tolerance, and then fixed in the entire course of treatment. In the second process, the same treatment fields and prescribed dose were used only for the initial plan and treatment. After several initial days of treatments, the treatment field shape and position were assumed to be adaptively modified using a computer-controlled multileaf collimator (MLC) in light of the predicted systematic and random setup errors. The prescribed dose was then escalated until the same normal tissue tolerance, as determined in the first treatment process, was reached.

RESULTS

The systematic setup error and the random setup error were predicted to be within +/-1 mm for the former and +/-0.5 mm for the latter at a > or = 95% confidence level using < or = 9 initial daily portal measurements. In the study, a large number of patients could be treated using a smaller field margin if the adaptive modification process were used. Simulation of the adaptive modification process for prostate treatment demonstrates that additional treatment dose could be safely applied to 64% of patients.

CONCLUSION

The adaptive modification process represents a different approach for use of on-line portal images. The portal imaging information from the initial treatments is used as feedback for reoptimization of the treatment plan, rather than adjustment of the treatment setup. Results from the retrospective study show that the treatment of individual patient can be improved with the adaptive modification process.

Functional analysis of ribosomal protein L2 in yeast mitochondria

The yeast nuclear gene RML2, identified through genomic sequencing of Saccharomyces cerevisiae chromosome V, was shown to encode a mitochondrial homologue of the bacterial ribosomal protein L2. Immunoblot analysis showed that the mature Rml2p is a 37-kDa polypeptide component of the mitochondrial 54 S large ribosomal subunit. Null mutants of RML2 are respiration-deficient and convert to [rho-] or [rho degrees ] cytoplasmic petites, indicating that Rml2p is essential for mitochondrial translation. RML2 is regulated transcriptionally in response to carbon source and the accumulation of Rml2p is dependent on the presence of the 21 S large rRNA. Site-directed mutagenesis showed that a highly conserved 7-amino acid sequence (Val336 to Asp342) of Rml2p is essential for function. Substitution of Gln for His-343, the most highly conserved histidine in the L2 protein family, caused cold-sensitive respiratory growth but did not affect the assembly of 54 S ribosomal subunits. Mitochondrial protein synthesis was normal in the His343 to Gln (H343Q) mutant grown at the permissive temperature (30 degrees C) and was severely impaired after growth at the nonpermissive temperature (18 degrees C). His343 corresponds to His229 in Escherichia coli L2, which has been implicated in a direct involvement in peptidyl transferase activity. The conditional phenotype of the H343Q mutant indicates that His343 is not essential for peptidyl transferase activity in yeast mitochondria.

Changes in telomerase activity and telomere length during human T lymphocyte senescence

It has been proposed that telomeres shorten with every cell cycle because the normal mechanism of DNA replication cannot replicate the end sequences of the lagging DNA strand. Telomerase, a ribonucleoprotein enzyme that synthesizes telomeric DNA repeats at the DNA 3' ends of eukaryotic chromosomes, can compensate for such shortening, by extending the template of the lagging strand. Telomerase activity has been identified in human germline cells and in neoplastic immortal somatic cells, but not in most normal somatic cells, which senesce after a certain number of cell divisions. We and others have found that telomerase activity is present in normal human lymphocytes and is upregulated when the cells are activated. But, unlike the immortal cell lines, presence of telomerase activity is not sufficient to make T cells immortal and telomeres from these cells shorten continuously during in vitro culture. After senescence, telomerase activity, as detected by the TRAP technique, was downregulated. A cytotoxic T lymphocyte (CTL) cell line that was established in the laboratory has very short terminal restriction fragments (TRFs). Telomerase activity in this cell line is induced during activation and this activity is tightly correlated with cell proliferation. The level of telomerase activity in activated peripheral blood T cells, the CTL cell line, and two leukemia cell lines does not correlate with the average TRF length, suggesting that other factors besides telomerase activity are involved in the regulation of telomere length.

Molecular genetics of the peptidyl transferase center and the unusual Var1 protein in yeast mitochondrial ribosomes

Mitochondria possess their own ribosomes responsible for the synthesis of a small number of proteins encoded by the mitochondrial genome. In yeast, Saccharomyces cerevisiae, the two ribosomal RNAs and a single ribosomal protein, Var1, are products of mitochondrial genes, and the remaining approximately 80 ribosomal proteins are encoded in the nucleus. The mitochondrial translation system is dispensable in yeast, providing an excellent experimental model for the molecular genetic analysis of the fundamental properties of ribosomes in general as well as adaptations required for the specialized role of ribosomes in mitochondria. Recent studies of the peptidyl transferase center, one of the most highly conserved functional centers of the ribosome, and the Var1 protein, an unusual yet essential protein in the small ribosomal subunit, have provided new insight into conserved and divergent features of the mitochondrial ribosome.

[A study of insulin sensitivity and its related factors in patients with non-insulin dependent diabetes mellitus and impaired glucose tolerance]

In order to evaluate insulin sensitivity and its related factors in abnormal glucose tolerance, 572 cases of non-insulin dependent diabetes mellitus (NIDDM), 647 cases of impaired glucose tolerance (IGT) and 543 normal controls were studied. The results showed that fasting insulin levels (FIns) and the prevalence of hyperinsulinemia were higher in NIDDM than that in IGT and higher in IGT than that in normal controls (P < 0.01). Insulin sensitivity index (ISI) [-ln(FInx x fasting blood glucose)] ranked from high to low in the order of normal controls, IGT subjects, newly-diagnosed NIDDM patients and patients with known NIDDM (P < 0.01). In each group ISI was smaller in obese subjects or patients than in non-obese ones. Mono-factor analysis demonstrated that ISI in each group was negatively related to body mass index (BMI) and positively related to high density lipoprotein (HDL)-cholesterol. ISI in NIDDM and IGT group was negatively related to blood pressure. Multiple analysis showed that the ISI had significantly negative correlation with BMI and some correlation with blood pressure and blood lipids. In conclusion, the patients with abnormal glucose tolerance had hyperinsulinemia and insulin resistance. ISI was related to some risk factors of vascular diseases.

[The influence of perindopril on intrarenal RAS in experimental diabetic rats]

OBJECTIVE

To examine the effect of perindopril on the intrarenal renin angiotensin system (RAS) in diabetic rats.

METHODS

Diabetes of rats was induced by a single injection of STZ. The rats were treated with perindopril (1 mg.kg-1.d-1) and the controls were given insulin only. Plasma and intrarenal renin activity (PRA, TRA) and angiotensin I (PAT I, TATII) were measured by radioimmunoassay in the diabetic rats at 1, 3, 6 months. Message RNA (mRNA) expression of renal angiotensinogen (TATO) and TATII receptor (TATII R) was assessed by slot blot hybridization.

RESULTS

At 6 month, TATII levels in the control group were significantly decreased compared with those of normal controls (P < 0.05), and TATII levels in perindopril treated rats were decreased remarkedly compared with those of the control group (P < 0.01). TRA was not different among the three groups at 3 to 6 months (P > 0.05). In slot blot hybridization TATII R mRNA expression in the control group was markedly increased compared with that of perindopril treated and normal control groups (P < 0.05, P < 0.01). TATO mRNA expression was not different among the three groups (P > 0.05) during the experimental period.

CONCLUSION

The abnormalities of intrarenal RAS existed in STZ induced diabetic rats, including the decrement of TATII content and the enhancement of TATII R mRNA expression. Perindopril could further decrease the level of intrarenal TATII, and inhibit its receptor mRNA expression.

Engineering of DNA binding proteins into site-specific cutters: reactivity of Trp repressor-1,10-phenanthroline chimeras

Trp repressor (TrpR) can be converted into a site-specific nuclease by chemical modification of the cysteine mutants TrpR D46C or TrpR E49C with 5-iodoacetamido-1,10-phenanthroline (OP). In the presence of cupric ion and 3-mercaptopropionic acid, TrpR-regulated operators are cleaved. The properties of these semisynthetic scission reagents have been compared. The E49C construct cleaves efficiently at two sites within the operator and the D46C cleaves at multiple sites. Molecular modeling indicates that the reason for the focused reactivity of E49C is that the OP is rigidly oriented in the protein-DNA complexes whereas the OP can adopt several orientations in TrpR D46C. Mutations and reaction conditions that increase the affinity of the repressor enhance the scission efficiency which approaches 100% within the acrylamide matrix. TrpR E49C-OP smoothly cleaves the trpEDCBA operator in a plasmid in a reaction dependent on the corepressor L-tryptophan. In the absence of tryptophan, non-specific cleavage of the plasmid is observed under the same conditions. Therefore, tryptophan not only directs cleavage to a specific site but also blocks it at non-specific sites. The analysis of the cleavage pattern of the trpEDCBA operator provides strong evidence for the tandem binding model in which protein-protein interactions stabilize binding on the DNA. TrpR E49C-OP should serve as the basis for the engineering of a family of highly specific semisynthetic scission reagents.

[Prevalence and risk factors of hypertension and coronary heart disease in the subjects with abnormal glucose metabolism]

The prevalence and risk factors of hypertension and coronary heart disease (CHD) in subjects with abnormal glucose metabolism (AGM) were studied in a population of 29,960 in the Capital Iron and Steel Corporation. The results showed that the prevalences of hypertension and CHD were 37.37% and 9.32% in diabetes group and 29.88% and 6.25% in impaired glucose tolerance group respectively. Both aging and obesity were the risk factors for AGM, hypertension and CHD. Hyperglycemia and hyperlipidemia were related to the occurrence of hypertension and CHD. Our results indicate that the prevalence of CHD and hypertension is significantly increased in AGM subjects, and they have many other risk factors of cardiovascular disease.

[Effects of insulin and captopril on growth of glomerular mesangial cells in STZ-induced diabetic rats]

OBJECTIVE

To observe the effects of insulin and captopril on growth of mesangial cells and on production of interleukin-6 (IL-6) and tumor necrosis factor (TNF) in culture media of glomerular cells.

METHOD

Streptozocin induced diabetic rats (DM rats) were compared with normal wistar rats.

RESULTS

The CPM value of 3H-TdR incorporated into mesangial cells in DM rats was significantly higher than that in Wistar rats. When the culture media was added by 5 x 10(-4) U/ml, 5 x 10(-3) U/ml and 5 x 10(-1) U/ml of insulin, the CPM value incorporated into mesangial cells and the concentration of IL-6 in the culture media of both DM and wistar rats were significantly higher than those of the control (no insulin). When captopril (10(-6) mol/L, 10(-4) mol/L, 10(-3) mol/L) was added into the media in different concentration, the cpm value of 3H-TdR and the concentration of TNF in DM rats were significantly lower than those of the control (no captopril). But the CPM value of 3H-TdR in Wistar rats was lower than that in the control, which was only seen in the concentration of 10(-3)M captopril.

CONCLUSION

Ins could promote 3H-TdR in corporation and increase the production of IL-6, and captopril inhibited 3H-TdR in corporation and decrease the production of TNF.

Identification of the yeast nuclear gene for the mitochondrial homologue of bacterial ribosomal protein L16

An open reading frame encoding a member of the L16 family of ribosomal proteins is adjacent to the URA7 gene on the left arm of chromosome II in Saccharomyces cerevisiae. The predicted L16-like polypeptide is basic (pl 11.12), contains 232 amino acids (26.52 kDa) and has 36% amino acid sequence identity to E. coli L16. Immunoblot analysis with polyclonal antibodies to the L16-like polypeptide showed specific cross-reaction with a 22,000 Mr mitochondrial polypeptide that co-sediments with the large subunit of the mitochondrial ribosome in sucrose density gradients. The levels of the L16 mRNA and protein varied in response to carbon source. In [rho degree] cells lacking mitochondrial rRNA, the L16 mRNA accumulated at normal levels, but the protein was barely detectable, indicating RNA-dependent accumulation of the L16 protein. Gene disruption experiments demonstrated that the yeast mitochondrial L16 is an essential ribosomal protein in vivo.

[Epidemiology of adult diabetes mellitus in a population of Capital Iron and Steel Company in Beijing]

To prevent the development of DM in susceptible individuals, 29859 subjects, aged from 30 to 64 years, from 32 units of the Company were studied by using WHO protocal and diagnostic criteria. The results showed that the average prevalence of DM and IGT was 3.63% and 4.19% respectively, standardized by census 1990 in Beijing, and it was increased with age. No sex difference in the prevalence of DM was found, but the prevalence of IGT was higher in females (5.55%) than in males. The obesity, overweight, positive DM family history and giant baby history, as well as high daily intake of protein were closely related to the prevalence of the disease. Smoking was in effective.

Discrimination of envelope frequency in one spectral region in the presence of modulation in another

This paper examines how discrimination of envelope frequency in one spectral region is affected by the presence of either correlated or uncorrelated modulation in another spectral region. Envelope-frequency discrimination thresholds, delta fe's, for a 60-dB SPL two-tone complex centered at 2 kHz were measured in the presence or absence of an auxiliary two-tone complex at another frequency. When present, the auxiliary complex had either the same envelope as the standard signal or an envelope that was uncorrelated with both the standard and variable signal. The results show that listeners can take advantage of correlation between simultaneous envelopes in different frequency regions to improve discrimination of a small change in envelope frequency, whereas the presence of uncorrelated envelopes causes interference with discrimination. Except when the auxiliary complex and the signal are close together in frequency, the discrimination advantage afforded by the correlated auxiliaries appears to reflect across-channel envelope processing. The discrimination interference caused by the uncorrelated auxiliaries, on the other hand, may reflect primarily within-channel interaction such as peripheral masking, although a small amount of across-channel masking also is apparent.

Absorption of fluorescein given under the upper lid

BACKGROUND

The need for a more efficacious approach to administer topical ocular medications prompted the authors to consider applying conventional eye drops under the upper lid rather than beneath the lower lid. Preliminary observations on patients with glaucoma using a beta-blocker beneath the upper lid suggested a drop in intraocular pressure into the normal range in some previously refractory patients being treated with the same medications. To test this clinical observation, the authors observed if there were any physiologic differences in topical fluorescein absorption into the anterior chamber when given beneath the upper lid versus the lower lid.

METHODS

A 5-microliters drop of fluorescein solution was placed under the upper-lid fornix of one eye and under the lower-lid fornix of the other eye in human volunteers, and absorption into the anterior chamber was measured at hourly intervals, for a total of 3 hours.

RESULTS

Hotelling T2 multivariate analysis for all 3 hours demonstrates that upper-lid administration of fluorescein results in significantly higher absorption of fluorescein into the anterior chamber than does lower-lid administration (P = 0.0088; for hours 2 and 3, the statistical differences is even more dramatic: P < 0.0044).

CONCLUSION

Using conventional eye drops beneath the upper lid, the authors observed increased absorption of fluorescein into the anterior chamber when compared with lower-lid administration. Profuse tearing, especially by younger subjects, significantly and rapidly diminished anterior chamber absorption of fluorescein. It is reasonable to consider further clinical studies to test this new approach to drug delivery.

Ion formation processes in the afterpeak time regime of pulsed glow discharge plasmas

The formation of ions following the termination of power in a pulsed glow discharge ion source is investigated. The populations of ionized species containing sputtered atoms M(+), M 2 (1) :, and MAr(+) are observed to maximize after the termination of discharge power. Collisions involving sputtered atoms and metastable argon atoms, Penning and associative ionization, are considered to be responsible for the formation of ions in the discharge afterpeak time regime. The domination of these ion formation processes during the afterpeak time regime is supported by the results from investigations of discharge operating parameters, metastable argon atom quenching, and ion kinetic energy distributions.

Activated C3 (C3b) in the nephritic glomerulus

An autoradiographic technique was developed to assess in the nephritic glomerulus the relative amount of C3 which is in the activated form, C3b, compared with the inactivated form, iC3b. Frozen renal biopsy sections from children and young adults with glomerulonephritis were assessed for the C3b fraction of total C3, using a radiolabeled monoclonal anti-C3c. Grain counts with this antibody, before and after reacting the section with 0.0002% trypsin, gave the relative amounts of total C3 and C3b, respectively. C3b was found in all diseases studied. To explain its presence, glomerular C3b acceptors which would restrict C3b inactivation were sought by immunofluorescence studies. C3b acceptor candidates were: IgG in aggregated form, IgA as found in the IgA nephropathies and the C3/C5 convertase, C4b,2a,3b. In acute post-streptococcal glomerulonephritis and membranoproliferative glomerulonephritis type III, diseases in which these acceptors were lacking, it is postulated that the nephritis strain-associated protein and absence of membrane cofactor protein, respectively, may be responsible for C3b deposition. The phlogistic effect of C3b is mediated largely by one of its products, C5b-9. However, the C3b: total C3 ratio failed to correlate with indices of glomerular inflammation, probably in part because the ratio is not a measure of total glomerular C3b.

Feedback inhibition of fully unadenylylated glutamine synthetase from Salmonella typhimurium by glycine, alanine, and serine

Bacterial glutamine synthetase (GS; EC 6.3.1.2) was previously shown to be inhibited by nine end products of glutamine metabolism. Here we present four crystal structures of GS, complexed with the substrate Glu and with each of three feedback inhibitors. The GS of the present study is from Salmonella typhimurium, with Mn2+ ions bound, and is fully unadenylylated. From Fourier difference maps, we find that L-serine, L-alanine, and glycine bind at the site of the substrate L-glutamate. In our model, these four amino acids bind with the atoms they share in common (the "main chain" +NH3-CH-COO-) in the same positions. Thus on the basis of our x-ray work, glycine, alanine, and serine appear to inhibit GS-Mn by competing with the substrate glutamate for the active site.

Effect of morphine on uptake of immunoglobulin G complexes by mesangial cells and macrophages

Focal glomerular sclerosis is the predominant renal lesion in heroin addicts. We studied whether morphine, a metabolite of heroin, could directly affect the uptake of immunoglobulin G (IgG) complexes by cultured mesangial cells (MC) and macrophages (MP). Pre-incubation of morphine (10(-6) M) decreased uptake of IgG complexes [morphine, 66,577 +/- 6,248 vs. control, 95,735 +/- 5,227 counts.min-1 (cpm).mg protein-1; P < 0.02] by MC. Morphine (10(-4)-10(-6) M) also inhibited (P < 0.01) uptake of 1,1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate-labeled low-density lipoprotein by MC. MP pretreated with morphine (10(-6) M) also showed significantly (P < 0.02) lower uptake of IgG complexes (control 94,959 +/- 4,980 vs. morphine, 58,360 +/- 11,608 cpm/mg protein). Binding studies carried out at 4 degrees C on MC and MP indicated that morphine did not modulate surface binding of IgG complexes. Naloxone, a morphine antagonist, also produced a rather decreased (P < 0.05) uptake of IgG complexes by both MP and MC and did not inhibit the effect of morphine on the uptake of IgG complexes. In vivo studies indicated that morphine-treated rats had a higher (P < 0.05) accumulation of aggregated human IgG complexes (125I-labeled ahIgG) in their glomeruli when compared with untreated rats (control rats, 256,929 +/- 40,008 cpm/g protein vs. experimental rats, 398,317 + 51,512 cpm/g). Increased accumulation of 125I-ahIgG in the glomeruli from morphine-treated rats may either be related to increased delivery of 125I-ahIgG into the mesangium or be a result of decreased drainage of 125I-ahIgG from the mesangium.(ABSTRACT TRUNCATED AT 250 WORDS)

Mesangial cell immune injury. Synthesis, origin, and role of eicosanoids

The synthesis, cell origin, and physiologic role of eicosanoids were investigated in a model of mesangial cell immune injury induced by a monoclonal antibody against the rat thymocyte antigen Thy 1.1 also expressed in rat mesangial cells. A single intravenous injection of the antibody resulted in enhanced glomerular synthesis of thromboxane (Tx)B2, leukotriene (LT)B4, and 12-hydroxyeicosatetraenoic acid (HETE), whereas that of PGE2 and PGF2 alpha was either unaltered or impaired. The enhanced eicosanoid synthesis was associated with decrements in glomerular filtration rate (GFR) and renal blood flow (RBF). Complement activation mediated both the increments in TxB2, LTB4, and 12-HETE and the decrements in GFR and RBF. The decrements in GFR were abolished by the TxA2 receptor antagonist SQ-29,548. Although both neutrophiles and Ia (+) leukocytes infiltrated glomeruli, glomerular LTB4 originated mainly from the latter. Platelets entirely accounted for the enhanced 12-HETE synthesis in isolated glomeruli and to a lesser extent for that of LTB4 and TxB2. Glomerular PGE2 and PGF2 alpha originated from mesangial cells as their impaired synthesis coincided with extensive mesangial cell lysis. The observations indicate that in mesangial cell immune injury vasoactive and proinflammatory eicosanoids originate from recruited or activated Ia (+) leukocytes and platelets and may exert paracrine effects on mesangial cells.

Soft filamentous woven polyester arterial prosthesis from China

Woven polyester arterial prostheses have traditionally been known for their tight construction and smooth surface which has limited their healing capacity and resulted in poor attachment of their internal and external capsules. A new woven prototype has recently been developed in the Peoples' Republic of China. Among its unique features are its high physical porosity, softness and flexibility. This study undertook a series of in vitro tests to characterize its structure and physical properties in comparison with four commercial polyester grafts of North American origin. In addition, an animal trial was completed in which the new prototype was implanted as an infrarenal aortic substitute in 20 dogs for periods ranging from 4 h to 12 month. The in vitro tests confirmed a unique lightweight, highly porous, satin weave construction. Because of its high water permeability, preclotting was necessary before implantation. Once preclotted and installed, no significant blood loss was observed, and 19 of the 20 grafts remained patent at the sacrifice. Rapid full-width healing was achieved with tightly bound capsules, and more extensive tissue ingrowth was observed. Further work is needed to evaluate its long-term durability as an arterial substitute.

The prevalence of subclinical hypothyroidism in adults with low-normal blood thyroxine levels

The purpose of this study was to determine whether subclinical hypothyroidism, defined as the state in which there is an elevation of thyrotropin blood level (TSH) with a low-normal blood thyroxine level (T4), can be found in clinically healthy subjects. We identified, by screening of adults in an ambulatory patient care facility, 67 persons with T4 at the lower range of normal (4.5-6.0 micrograms/dL) who were free of acute nonthyroidal illness and who were not on medications known to affect T4, other than long term thyroxine therapy. TSH was determined in all 67 persons, whose ages ranged from 25 to 87 years. Nineteen persons in this population had a history of thyroid disease and 48 did not. Elevation of TSH was found in 13 subjects (19%), seven of whom had a history of thyroid disease. The prevalence of TSH elevation was 50% in those with T4 of 4.5- less than 5.0 micrograms/dL, 26% in those with T4 of 5.0-5.5 micrograms/dL, and 8% in those with T4 of greater than 5.5-6.0 micrograms/dL (p less than 0.02). Three of these 13 patients had been on thyroxine therapy at the time of the survey, and their thyroxine doses were adjusted, whereas five others were started on thyroxine therapy subsequent to the survey. Treatment doses as low as 0.05 mg/day increased the T4 and returned the TSH to normal in six patients. In two of five patients who went untreated, there was a substantial fall in T4 and/or a rise in TSH.(ABSTRACT TRUNCATED AT 250 WORDS)

Refractive index measurement using a standard compensating method

The first three significant digits of a sample's refractive index are compensated by a standard, therefore a precise measurement, which is the same as the refractive index of the standard, can be obtained. The method only needs a thin sample.