[New species of Natronobacterium]

An extreme haloalkalophilic bacterium HAM-2 with pleomorphic rods was isolated from Hamatai soda lake in Inner Mongolia Autonomous Region. Growth occurs in 12%-30% NaCl, no growth below 12%, optimum 17.5%. pH range for good growth 7.8-10.4, optimum 9.0-9.5. The strain HAM-2 is non-motile, Gram-negative, pleomorphic, cell of which were 1.0-2.0 by 2.0-5.0 microns in size in liquid medium. The major polar lipids of the organisms are phosphatidylglycerol phosphate and phosphatidyglycerol and contains an unidentified phospholipid as a minor component PL4. G + C contant of DNA is 59.5 mol%. Based on the characteristics, the strain HAM-2 could be included in the genus Natronobacterium, but since HAM-2 differs from reported four species of this genus in cell shape, polar lipids and biochemical features. The name Natronobacterium innemongoliae sp. nov. is proposed. The type strain is designated HAM-2.

Reduction of choline acetyltransferase mRNA in the septum of developing rat exposed to inorganic lead

We previously reported that perinatal exposure to low levels of lead (Pb) results in a pronounced reduction of choline acetyltransferase (ChAT) activity in the septohippocampal pathway of the rat. In the present study we employed a ChAT specific 43-base oligonucleotide hybridization probe to compare the developmental expression of ChAT mRNA and ChAT activity in the septum of normal and Pb-exposed rats. Rats were exposed to Pb via maternal administration of 0.2% solution of Pb acetate in drinking water from one week before birth through postnatal day 21 (PN21). In normal animals, the developmental changes in the ChAT mRNA and activity levels were temporally correlated and approached adult levels by PN21. In the Pb-exposed pups, ChAT mRNA and activity levels were reduced respectively by 69% and 50% at PN7, 47% and 33% at PN14, and 47% and 22% at PN21. In contrast, Pb exposure had no significant effect on either ChAT mRNA or ChAT activity in the dams. These results indicate that cholinotoxicity of Pb in the septohippocampal pathway of the rat involves developmental stage-dependent disruption of ChAT gene expression.

Synthesis and antitumor activity of spin labeled derivatives of podophyllotoxin

Three new nitroxyl labeled derivatives of podophyllotoxin 4-6 have been synthesized and evaluated for their antitumor activity in vitro. Compounds 4-6 showed significant inhibitory activity against human nasopharyngeal carcinoma KB,lung cancer A549 and stomach carcinoma SGC-7901 cells, as well as mouse leukemia L1210 and P388 cells. Compounds 4 and 5 exhibited comparable or superior activity to clinically used etoposide (VP-16,2) in their inhibition of these cell lines.

Changes in average blood pressure and incidence of high blood pressure 1983-1984 to 1987-1988 in four population cohorts in the People's Republic of China. The PRC-USA Cardiovascular and Cardiopulmonary Epidemiology Research Group

OBJECTIVE

To assess comparative changes in systolic and diastolic blood pressure and incidence of high blood pressure over 4 years, and factors related to these changes, in northern and southern, urban and rural adults in the People's Republic of China.

SETTING

This is a prospective study of populations surveyed by standardized methods in 1983-1984 and 1987-1988 in north China, Beijing area steel mill workers and farmers, and south China, Guangzhou area shipyard workers and farmers.

SUBJECTS

The subjects were 8805 men and women aged 35-54 years at baseline (1983-1984), of whom 7338 were non-hypertensive (systolic blood pressure < 140, diastolic blood pressure < 90 mmHg, not being administered antihypertensive drugs).

MAIN OUTCOME MEASURES

The main outcome measures were 4-year changes in systolic and diastolic blood pressures and the 4-year incidence of high blood pressure in persons not hypertensive at baseline.

RESULTS

At baseline, the average systolic and diastolic blood pressures were higher for Beijing than for Guangzhou cohorts. At resurvey the average systolic blood pressure had increased for seven of eight sex-city-setting cohorts (all but Guangzhou urban men). The Beijing urban cohorts had the greatest increases (men 6.2 mmHg, women 4.9 mmHg, slopes of 1.6 and 1.2 mmHg/year). The incidence of high blood pressure was higher for Beijing than for Guangzhou cohorts in all four comparisons (men and women, urban and rural). Beijing men, urban and rural, had the highest incidence rates (about 21%). In multiple logistic analyses by sex, variables significantly related to 4-year high blood pressure incidence were city, baseline systolic blood pressure and body mass index, change in weight, and, for men, baseline alcohol use and heart rate.

CONCLUSION

Modifiable lifestyle traits, previously shown to be related to blood pressure and high blood pressure in cross-sectional studies, also relate to the incidence of hypertension.

Enhanced sympathetic neurite outgrowth on rat hippocampal tissue sections following septal lesions

Cryostat sections of the rat hippocampus were used as tissue culture substrates for embryonic chick sympathetic explants. Neurite outgrowth from these explants was found to be significantly greater on sections taken from animals with septal lesions as compared to those receiving sham operations. This finding suggests that septal denervation leads to hippocampal substrate changes that enhance sympathetic neurite outgrowth in vitro, perhaps analogous to the sympathetic sprouting response that occurs in vivo.

Developmental age-dependent upregulation of choline acetyltransferase and vesicular acetylcholine transporter mRNA expression in neonatal rat septum by nerve growth factor

We examined the effect of intraventricular injection of nerve growth factor (NGF) on the choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) mRNA expression in the septa of neonatal rats. Rat pups were injected with 2.5 S NGF or cytochrome-c (control) on postnatal days (PN) 4 and 18, and sacrificed 3 days after injections for analysis of ChAT and VAChT mRNA levels by dot-blot hybridization of total septal RNA. In the NGF-treated pups, the ChAT and VAChT mRNA levels were elevated 3- and 2-fold, respectively, at PN7, and 1.8- and 1.3-fold at PN21. These results indicate that (1) NGF upregulates the expression of both ChAT and VAChT genes, (2) NGF has a greater effect on the expression of ChAT mRNA than VAChT mRNA, and (3) the effect of exogenous NGF on the expression of both genes diminishes with developmental age.

[The effect of cytokines on the liver necrosis]

OBJECTIVE

To investigate the effect of cytokines on liver necrosis.

METHODS

We injected IL-1, IL-6, IFN gamma, TNF alpha with or without D-galactosamine (D-GAL) into the abdominal cavity of mice separately.

RESULTS

There was no effect on hepatocyte of normal mice after injection of IL-1, IL-6, IFN gamma alone or together. The serum total bilirubin (TBIL) and liver necrosis of mice increased more markedly by using of TNF alpha, IL-6 or IFN gamma separately with D-GAL (TBIL: 46.2 +/- 10.6 micromol/L, 44.6 +/- 12.9 micromol/L, 41.9 +/- 14.9 micromol/L), then by D-GAL alone (TBIL: 27 +/- 11 micromol/L) also the serum TBIL of mice and liver necrosis also increased after injection of IL-1, IL-6 with D-GAL and TNF alpha.

CONCLUSION

Cytokines like IL-1, IL-6, IFN gamma and TNF alpha joined the process of hepatocyte necrosis. They can enhance the degree of liver necrosis induced by D-GAL.

Cholinergic denervation-like changes in rat hippocampus following developmental lead exposure

We investigated the effects of developmental lead exposure from embryonic day 16 (E16) through postnatal day 28 (PN28), on cholinergic and catecholaminergic markers in the septohippocampal pathway in rats through fourth month of age. Lead exposure resulted in a persistent 30-40% reduction of [3H]hemicholinium-3 ([3H]HC-3) binding in the hippocampus through PN120, and 20-30% reduction of septal and hippocampal choline acetyltransferase (ChAT) activity which persisted through PN84 but returned to control levels in both septum and hippocampus at PN112. The muscarinic ligand [3H]quinuclidinyl benzylate ([3H]QNB) binding was reduced in the septum at PN28 but did not differ significantly from controls at PN56-PN112. Neither short- nor long-term effects of Pb exposure on [3H]QNB binding were seen in the hippocampus. Similar to the effects of fimbria-fornix transection, Pb exposure resulted in a long-term 50-90% increase of tyrosine hydroxylase(TH) activity in the hippocampus, although neither treatment affected TH activity in the septum. The lead-induced increase in hippocampal TH was significantly attenuated by superior cervical ganglionectomy. It is concluded that the effects of perinatal lead exposure resemble in several respects those seen following surgical disruption of the septohippocampal pathway in adult animals. The denervation-like effects in the hippocampus may be an important factor in long-term learning and cognitive impairments following developmental exposure to low-levels of lead.

Simple algorithm for large-grid phase reconstruction of lateral-shearing interferometry

A simple zonal approach is proposed for estimating phase distribution on large grids. The estimation is based on phase differences that are precisely measured in two orthogonal directions by a lateral-shearing interferometer. It requires only O(N(2)) operations for reconstructing a phase distribution on an N × N grid. Computer simulation and experimental results are demonstrated to show the effectiveness of the new algorithm.

[Study on the relationship between uterine bleeding with intrauterine device and viral infection]

OBJECTIVE

To study the relationship between uterine bleeding with intrauterine device (IUD) and virus infection.

METHODS

Virus isolation from endometrium samples both with IUD and without IUD was performed with rabbit kidney cell. The cell pathogen effect (CPE) directed the positive isolation. All isolated viruses were further identified by polymerase chain reaction (PCR) for human cytomegalovirus (HCMV) and by neutralizing test for herpes simplex virus type II (HSV-II).

RESULTS

The endometrial samples were obtained from four groups: 113 patients with uterine bleeding with IUD; 109 healthy women, without uterine bleeding with IUD; 24 healthy women without IUD and 11 patients with uterine bleeding without IUD. The rates of virus isolation in four groups mentioned above were 59.29%, 19.27%, 16.67% and 63.64% respectively. The positive rates for HCMV and HSV-II in the four groups were 38.81%, 19.05%, 1/4, 3/7 and 23.88%, 23.87%, 1/4, 0.00% respectively. The unidentified viruses were 37.31%, 57.14%, 2/4 and 4/7 respectively.

CONCLUSIONS

These results showed that some endometrial samples from both the bleeding groups and the controls were infected by HCMV and HSV-II. The incidence of virus infection in women with uterine bleeding with IUD was much higher than that of the controls, but similar to that is the patients with uterine bleeding without IUD. The results suggested that IUD could activate latent viruses (HCMV, HSV-II) infection and induce bleeding in certain conditions.

[An experimental study on homoharringtonine and glaucoma surgery]

PURPOSE

To test the inhibiting effect of a Chinese herbal drug. Homoharringtonine (HH) on the wound healing process at the filtering site in an experimental model.

METHODS

Posterior sclerectomies were performed in 20 rabbits. Postoperatively one eye of each rabbit received subconjunctival injections of HH and fellow eye received saline injections in a randomized masked fashion.

RESULTS

14 days after operation, intraocular pressure decreased significantly compared with that of control (P < 0.05). The number of filtration blebs was greater than that of control (14/6). On pathological examination, the number of fibroblasts per square measure of cross section of tissue cut from filtration region that was diminished significantly compared with that of control (P < 0.01). There were no serious and permanent ocular toxic and side effects.

CONCLUSIONS

The study suggests that the HH can inhibit cicatrization at the glaucoma filtering site, promote the formation of filtering blebs and provide a sufficient evidence for the further clinical use of HH.

Reduced densities of sodium-dependent [3H] hemicholinium-3 binding sites in hippocampus of developmental rats following perinatal low-level lead exposure

We investigated the effect of perinatal, low-level lead exposure on [3H]hemicholinium-3 (HC-3) binding in the hippocampus of postnatal rat. Rat pups were maternally lead-exposed from gestational day 16 through postnatal day 28 (PN28). In control animals, the [3H]HC-3 binding sites increased from 7 fmol/mg protein at postnatal day 1 (PN1) to 14 and 35 fmol/mg protein at PN7 and PN14, respectively, and reached adult values of 50 fmol/mg protein, at PN21 and PN28. In lead-exposed litters, the [3H]HC-3 binding was reduced by 30-40% throughout the early postnatal development and remained 40% below control values in PN60 animals, one month after termination of lead exposure. The Pb-induced reduction in HC-3 binding was associated with a similar decrease in ChAT activity and was comparable to the effect of localized lesion of medial septum. Septal cell counts in the lead-exposed PN21 rats indicated a 22% reduction in the number of ChAT-immunoreactive cells in the medial septum/vertical diagonal band (MS/vDB) complex although cell numbers in the horizontal limb of the diagonal band (hDB) were not altered. These results suggest that perinatal, low-level lead exposure results in a reduced density of cholinergic nerve terminals in the hippocampus, either due to impaired development or degeneration of the cholinergic projection neurons in the MS/vDB complex.

Biochemical and biophysical characteristics of mitochondria in the hypertrophic hearts from hypertensive rats

A comparative study of the biochemical and biophysical characteristics of myocardial mitochondria was conducted in 16-weeks-old male stroke-prone spontaneously hypertensive rats (SHRsp) and normotensive Wistar-Kyoto control rats (WKY) (n = 6-12). Cardiac and ventricular weights of SHRsp were significantly higher than those of the WKY group. The average amounts of mitochondria (Mit) and sarcoplasmic reticulum (SR) proteins isolated from the ventricle of SHRsp were 37% and 25% greater, respectively, when compared with those of WKY. Mit cytochrome c oxidase activities (mumol/min/mg) were 4.63 +/- 0.71 for SHRsp and 5.55 +/- 0.50 for WKY myocardium (mean +/- s), so that the activity of the former was significantly reduced by 17% (P < 0.01). Mit Ca2+, Mg(2+)-ATPase activity (mumol/min/mg) of SHRsp was 24% lower than that of WKY myocardium (P < 0.01). The fluorescence polarization of myocardial Mit membrane labelled with DPH (1, 6-diphenyl-1, 3, 5-hexatriene) in hypertensive rats was not different from that in control rats. The spectra of intrinsic protein fluorescence in 300-380 nm at an excitation wavelength of 290 nm were also identical in the Mit or SR between SHRsp and WKY myocardium. An ultrastructural analysis showed that there were more new-born Mit with smaller volumes and an increased number of isolated Mit in vitro from SHRsp myocardium, while there were larger Mit volumes isolated from WKY myocardium. These results demonstrated the disorder of mitochondrial energy metabolism in hypertrophied myocardium from SHRsp, which may be involved in the abnormality of myocardial calcium metabolism.

Morphometric evaluation on myocardial protection of cold crystalloid versus warm blood cardioplegia

Twenty patients undergoing open-heart valve replacement were divided randomly into two groups in this study; intermittent perfusion of cold crystalloid (St. Thomas Hospital solution) with hypothermic cardiopulmonary bypass (CPB) (hypothermic group) and continuous administration of warm blood cardioplegia with normothermic CPB (normothermic group) respectively. Tissue samples were taken from the right atrium before weaning from CPB and from the right appendage 30 minutes after removal of the cross-clamp. The results of pathological study in these two groups were as follows: the structural alterations were most severe during the ischemic period in the hypothermic group. Damages of the myocardial mitochondria examined with transmission electron microscope were found more severe in the hypothermic group than in the normothermic group, and in the reperfusion period than in the ischemic period. Loss of integrity of the mitochondrial membrane could be noted during reperfusion in the hypothermic group. The surface to volume ratios of mitochondria of each period of the two groups were calculated by computerizing the microphotographs of the myocardium. It was shown that the average of the surface to volume ratios was smallest in the reperfusion period in the normothermic group. It seemed that the volumes of the mitochondria were larger in the warm group than in the cold one. Probably the results were due to more severe damages of the mitochondrial membranes in the hypothermic group, which led to the release of the contents out of the mitochondria while in the normothermic group, the sodium-pump was disordered and it made the mitochondria swell. Pathologically, blood cardioplegic perfusion with the use of normothermic CPB is a feasible method for myocardial protection in open-heart surgery.

Morphology and morphogenesis of hepatitis E virus (strain 87A)

The morphology and morphogenesis of isolated hepatitis E virus (HEV, strain 87A) were observed by electron microscopy (EM) and immune electron microscopy (IEM). Progressively developing local vesicles, virions accumulation in crystalline arrays and viroplasmic focus were seen in cytoplasm of infected cells. Replication and assembly of the new generation viruses were closely associated with rough endoplasmic reticulum (RER), inclusion body (IB) and microfibrils. Condensation and margination of chromatin, dispersion of nucleolar material, nuclear membrane alteration and masses of threads, granular material, and fibrillar component of the nucleus were frequently found. These changes revealed that this strain virus was confirmed as a RNA virus. The shape of the virus particles appeared approximately spherical whether the specimens were from the tissue culture crude suspension or purified highly concentrated preparations. The size of the virion was about 30 nm in diameter. The viral particles appeared unsmooth and irregular in outline. The spike-like structures may be occasionally observed on the surface of some viral capsides. The diameter of the strain 87 A virus is larger than the picornavirus and smaller than the calicivirus. This strain virus is different from classical calicivirus in without the cup-shaped surface depressions. The new genus, heparnavirus genus of caliciviridae family should be proposed for HEV.

Neurite degeneration elicited by apolipoprotein E peptides

Apolipoprotein E (apoE) has been localized to the neurofibrillary tangles and beta-amyloid-containing plaques found in the cortex of patients with Alzheimer's disease (AD) (14, 28), suggesting that apoE may play a role in this disorder. Recently, synthetic peptides containing a sequence within apoE (amino acids 141-155) were found to be cytotoxic to T lymphocytes in culture. In the present study, tandem presentation of the apoE sequence E141-155, as well as longer monomeric peptides that include this domain, was found to cause extensive and specific degeneration of neurites from embryonic chick sympathetic ganglia in vitro. These results, together with the observation of strong beta A4/apoE binding in vitro and the disproportionate occurrence of the epsilon 4 allele in both familial and sporadic AD patients, suggest that peptide sequences associated with apoE may contribute directly to neurodegenerative processes.

A parathyroid hormone antagonist stimulates epidermal proliferation and hair growth in mice

The biologic action of parathyroid hormone (PTH)-related peptide (PTHrP) in normal skin was investigated in cultured human keratinocytes and in SKH-1 hairless mice. The results indicate that the PTHrP agonists human PTHrP-(1-34) and PTH(1-34) are potent inhibitors of epidermal cell proliferation. [Nle8,18,Tyr34]bovine PTH-(7-34)-amide, an antagonist of the PTH/PTHrP receptor, blocked the inhibitory effect of PTH-(1-34) in cultured keratinocytes. In the SKH-1 mice, PTH-(7-34) caused a 244% increase of [3H]thymidine incorporation into isolated epidermal DNA and 246% and 180% increases in the number and length of hair shafts, respectively. Thus, PTH and PTHrP may play an important role in the normal physiology of skin, and their agonists and antagonists have potentially wide therapeutic applications in the treatment of hyperproliferative skin disorders and aging skin and could also be effective in stimulating and maintaining hair growth.

[Mapping of full-length murine renin-2 gene]

A 24kb fragment containing full-length renin-2 gene and its flanking sequence was obtained by digesting the pKG-R2D with XhoI. This fragment was cleaved with single enzyme (EcoRI, KpnI and BamHI), and combined enzymes (EcoRI/KpnI, KpnI/BamHI and BamHI/EcoRI), respectively. The digests were electrophoresed on 0.8% agarose plates and transferred onto NC membranes. Radioactive probes of 735bp and 1400bp, templates of which were from half and full-length of renin-1 cDNA, respectively were used for Southern hybridization. On the basis of electrophoresis and hybridization patterns, a restriction map was constructed in this paper.

[Laser suture lysis following trabeculectomy]

Trabeculectomies with tightly sutured scleral flap was performed on 49 eyes of 45 patients with angle closure or open angle glaucomas, the experimental group, of which 41 eyes underwent laser suture lysis subsequently. After a mean period of follow-up 14.7 months (12-36 months), the average intraocular pressure was decreased from pre-operative 5.93 kPa (44.5 mmHg) to post-operative 1.96 kPa (14.7mmHg). The experimental group of patients was compared with the control group, 41 eyes of 39 cases at the same period randomly undergoing trabeculectomy without laser suture lysis. The control rate of intraocular pressure is higher (89.8%:73.2%) and the incidence of ocular complications (such as, shallow anterior chamber, choroid detachment, hyphema, lens opacity) is significantly lower in the former group, showing that trabeculectomy with following laser suture lysis is a safe and effective anti-glaucoma surgery. The advantages, points for attention and experiences of laser suture lysis have been introduced in the paper.

Infection of human endothelial cells by Rickettsia rickettsii causes a significant reduction in the levels of key enzymes involved in protection against oxidative injury

The activities of glucose-6-phosphate dehydrogenase, catalase, and glutathione peroxidase were significantly decreased in human endothelial cells infected with the obligate intracellular bacterium Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. This observation lends additional support to our hypothesis implicating oxidative damage in endothelial cell injury caused by this microorganism.