Disposable 1-day Acuvue contact lenses for the delivery of lomefloxacin to rabbits' eyes

PURPOSE

To investigate the ability of a disposable soft contact lens (1-Day Acuvue) to deliver lomefloxacin, a fluoroquinolones antibiotic, into the cornea and aqueous humor of rabbits.

METHODS

Experiments were conducted on adult albino rabbits. 1-Day Acuvue lenses were immersed for 1 hour in commercially-available lomefloxacin eye solution and then placed on the cornea. After 0.5, 2, 4,6, and 8 hours, the animals were killed and the lenses were removed and placed into a 20 mL saline bath. Corneal tissue and aqueous humor samples were also obtained at these times. The release of lomefloxacin from the lenses was calculated by measuring the amount of drug remaining in the lenses after removal from the rabbit eyes. The concentration of lomefloxacin in the cornea and anterior chamber following the wearing of lomefloxacin-loaded lenses was compared with the concentrations following frequent-drop therapy (one drop of lomefloxacin hourly for 8 hours).

RESULTS

In vivo, lomefloxacin was released from 1-Day Acuvue lenses gradually over 8 hours. The cornea and aqueous humor levels in the eyes following the wear of lomefloxacin-loaded lenses were significantly higher than those achieved by frequent-drop therapy. The drug levels in the cornea and aqueous humor generally remained above the 90% minimal inhibitory concentration for 8 hours in the 1-Day Acuvue lens group.

CONCLUSIONS

1-Day Acuvue contact lenses soaked in 0.3% lomefloxacin can release sufficient amounts of lomefloxacin and in this study produced higher levels in both the cornea and aqueous humor than that achieved by frequent-drop therapy for up to 8 hours. We conclude that 1-Day Acuvue contact lens can be used as a drug delivery system for lomefloxacin.

Enmein type diterpenoids from Isodon japonica

Two enmein type diterpenoids, taibaijaponicains A and B, were isolated from the ethanol extract of the leaves and branches of Isodon japonica. Their structures are designated as 6beta,11alpha-dihydroxy-16alpha-methoxymethyl-6,20-epoxy-6,7-seco-ent-kaur-15-one-1,7-olide and 3beta-acetoxy-6beta,11alpha-dihydroxy-16alpha-methoxymethyl-6,20-epoxy-6,7-seco-ent-kaur-15-one-1,7-olide, respectively, on the basis of detailed spectroscopic analyses.

Cloning and analysis of mold-specific genes in the dimorphic fungus Histoplasma capsulatum

A critical feature in the pathogenesis of the respiratory pathogen Histoplasma capsulatum is the conversion from the mold form (found in soil) to the yeast form in the lungs of the host. Little is known about the molecular biology of Histoplasma dimorphism. In particular, the possible roles of genes which are transcriptionally silent in yeast (i.e. mold-specific) have not been studied. We have produced a cDNA library highly enriched for mold-upregulated clones by fragmenting cDNA and removing yeast-specific and common sequences with a highly efficient enzyme degrading subtraction method. Screening of randomly selected clones identified cDNA fragments representing 16 different mold-upregulated genes. Because multiple cDNA fragments can be treated as alleles in a genetic screen, we were able to apply probability analysis to estimate the total number of mold-upregulated genes. We estimate that there are 27 upregulated genes; cDNA fragments of 16 have been isolated. Here we report the first isolation and analysis of cDNA from two mold-specific genes, MS8 (GenBank AF292398) and MS88 (GenBank AF357882). The MS8 transcript was very strongly expressed in mold but not detected on Northern blots with yeast RNA. The putative MS8 protein was predicted to be 21.3 kDa (203 aa), very rich in glutamine and glycine and had a calculated pI of 6.76. The MS88 transcript was weakly expressed in mold and not detected in yeast. The putative MS88 protein was predicted to be 22.5 kDa (219 aa) with a pI of 4.46. GenBank similarity searches revealed that the putative MS8 protein was similar to a glutamine-rich protein, of unknown function, from the fungus Colletotrichum gloeosporioides (GenBank U94186). No significant matches were found for the putative MS88 protein.

Variations in cardiac diastolic function in hypertensive patients with different left ventricular geometric patterns

To evaluate the alteration of cardiac function in hypertensive patients with different left ventricular geometric patterns. Echocardiography was used to study left ventricular geometry and cardiac diastolic function in 117 cases of essential hypertension, with 45 normal cases as controls. Echocardiographic date were used to calculated the left ventricular mass index (LVMI) and relative wall thickness (RWT), which values in turn were used to divide the subjects into four groups. The left atrial dimension of the group, with the exception of these hypertensives who showed normal geometry, was larger than that of the control group. The damage of peak of E velocity, peak of A velocity, E/A and the slope between the E and F points (E to F slope) were greater than in hypertension than in the control group. The concentric hypertrophy group and eccentric hypertrophy group suffered more serious damage of left ventricular diastolic function than the concentric remodeling group, and damage of left ventricular diastolic function in the concentric remodeling group was greater than that in the normal geometry group. The degree of cardiac diastolic function damage differed among patients with different left ventricular geometric patterns, when the cardiac structure was changed, the degree of cardiac diastolic function damage increased.

[Magnetic stimulation: theory and advance]

Magnetic stimulation is a noninvasive diagnostic and therapeutic technique. The basic theory of magnetic stimulation is presented briefly. Its advances are elaborated in three aspects of mechanism, instrumentation and applications. The problems in focality, location, safety and its trend are discussed.

Separation and determination of podophyllum lignans by micellar electrokinetic chromatography

A micellar electrokinetic chromatography method was established for the quantitative analysis of seven podophyllum lignans in Podophyllum emodi Wall. var. chinesis sprague. The optimum buffer system was 10 mM NaH2PO4-5 mM borate-100 mM sodium dodecylsulfate-30% isopropanol (pH 7.20). Voltage was 18 kV and detection at 214 nm. The second derivative chromatogram was used to determine a low-content component and those not fully separated from adjacent ones. The RSD values of migration times and peak areas were <2.2 and <5.5%, respectively. The effects of several CE parameters on the resolutions were studied systematically.

Vascular endothelial growth factor: acting as an autocrine growth factor for human gastric adenocarcinoma cell MGC803

Vascular endothelial growth factor (VEGF) is known to be a highly specific mitogen for endothelial cells through two high-affinity tyrosine kinase receptors, VEGFR-1 and VEGFR-2, which are almost specifically expressed in endothelial cells. However, recent findings showed that VEGF receptors may also expressed by nonendothelial cells, especially by tumor cells. To further understand the functional expression of VEGF receptors by nonendothelial cells, our preliminary screening detected the expression of VEGFR-2 in 115 different paraffin-embedded cancer specimens including 35 cases of bladder tumor, 30 cases of breast cancer, 25 cases of intestinal cancer, and 25 cases of lung cancer with immunohistochemistry. The results showed that VEGFR-2 was widely expressed in different tumor tissues. By reverse transcription PCR, NCI-H23, NCI-H460, MGC803, MDA-MB-231, 293, and MCF7 cells were evaluated for the mRNA expression of both VEGF and VEGFR-2. The data indicated that all these tumor cell lines expressed detectable amounts of VEGF mRNA, but only 293, MCF7, and MGC803 cells coexpressed VEGFR-2. Immunoblot analysis also demonstrated the expression of VEGFR-2 at protein level. We further demonstrate that exogenous rhVEGF(165) could stimulate cell growth in MGC803, a tumor cell line derived from gastric adenocarcinoma, in a dose- and time-dependent manner. Furthermore, the antibodies against rhVEGF(165) and VEGFR-2 could block rhVEGF(165)-mediated proliferation of MGC803 cells. These unexpected results provided direct evidence that VEGF may act as an autocrine growth factor to induce the proliferation of gastric adenocarcinoma cells as well as tumor angiogenic cells, thus suggesting a promising tumor therapeutic application based upon the VEGF system.

[Study on the construction of standard D1S549 allelic ladder via molecular cloning and its genetic polymorphism in Chinese three populations]

OBJECTIVE

To resolve the problem of the accuracy and standardization of STR-PCR typing in forensic practice, we have designed a new method to produce standard D1S549 allelic ladder.

METHODS

Eight different PCR amplified D1S549 allelic fragments were isolated from the gel, eluted into the distilled water and re-amplified by PCR. The purified allelic fragments were then blunt-end subcloned individually into the pUC plasmid vectors and transfected into competent E. coli DH5 alpha cells.

RESULTS

The sequencing results confirmed that the size and the construe of the inserts were correct. The recombinant plasmids DNA with 8 inserts were then used as templates for re-amplification to generate D1S549 standard ladder, with which the genetic polymorphisms of D1S549 locus in Chinese Han population in chengdu, Hui population in Gansu and Wei population in Xinjiang were studied.

CONCLUSION

The results showed that the standard ladder made via this method is excellent, and D1S549 locus is robust for genetic research and forensic application.

Triterpenoid saponins from Clematis tangutica

Two new triterpenoid saponins, tanguticoside A and B along with seven known saponins vitalboside B, alpha-hederin, saponin PK, beta-hederin, saponin PJ3, saponin PE, and ciwujianoside A were isolated from aerial part of Clematis tangutica. By chemical and spectral evidences methods, the structures of tanguticoside A and B were elucidated as 3-O-beta-D-glucopyranosylhederagenin 28-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside and 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosylhederagenin 28-O-alpha-D-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranoside, respectively.

Intrathecal injection with methotrexate plus dexamethasone in the treatment of central nervous system involvement in systemic lupus erythematosus

OBJECTIVE

To investigate the effect of intrathecal injection (i.t.) with methotrexate (MTX) plus dexamethasone (DXM) in treating central nervous system involvement in systemic lupus erythematosus (CNS lupus).

METHODS

Twenty-four CNS lupus patients that were refractory to conventional steroid therapy were selected for i.t. with MTX 10-20 mg plus DXM 10-20 mg. The effects and side effects of i.t. were closely observed.

RESULTS

The symptoms and signs of 22/24 (91.7%) CNS lupus patients receiving i.t. improved considerably. Cerebrospinal fluid pressure, protein and WBC levels declined from 201.5 +/- 155.4 mm H2O, 145.2 +/- 87.6 mg/dl and 25.1 +/- 14.3/mm3 to 128.7 +/- 108.1 mm H2O, 60.8 +/- 38.3 mg/dl and 6.8 +/- 2.1/mm3 respectively. Transient side effects were observed in 4 patients: 1 with itching sensation of lower limbs, 2 with headache and 1 with incontinence.

CONCLUSION

I.t. with MTX plus DXM is a promising method for treating CNS lupus and deserves further investigation.

Extracellular domain of YWK-II, a human sperm transmembrane protein, interacts with rat Mullerian-inhibiting substance

The YWK-II protein in human spermatozoa is structurally related to the betaA4-amyloid precursor protein of Alzheimer disease and has high similarity with amyloid precusor homologues. Antibodies to the YWK-II protein agglutinate human spermatozoa and may be a potential cause of infertility. In the present study, a yeast two-hybrid system (MATCHMAKER Two-Hybrid System 2; Clontech, Palo Alto, CA) was used to screen a rat ovary cDNA library for potential ligands capable of interacting with the YWK-II component. Mullerian-inhibiting substance was found to interact with the extracellular domain of YWK-II protein. The interaction was confirmed by a binding experiment in vitro and surface plasmon resonance assays. The recombinant Mullerian-inhibiting substance can significantly increase the viability and longevity of human spermatozoa after 5 and 22 h of incubation, presumably through binding the YWK-II component on the sperm membrane. The results of this study indicate that the YWK-II sperm membrane protein may function as a receptor for Mullerian-inhibiting substance.

Magnetic tracker calibration for an augmented reality system for therapy

Magnetic trackers are widely used position/orientation measurement devices in interactive computer systems. These trackers output six-degree-of-freedom position and orientation of their receiver coordinates with respect to their transmitter coordinates. It is a potential solution for real-time position/orientation measurement in an augmented reality system for therapy (ART). However, an obstruction to be overcome is that a magnetic tracker is vulnerable to measurement inaccuracy caused by magnetic field distortions (including ferric and non-ferric distortions) when it is used in metallic environments. The purpose of this paper is to discuss calibration methods used to compensate distortions produced by metallic objects which are moving during the measurement procedure, but fixed with a receiver. Past work on the calibration of magnetic trackers has concentrated on static distortions, which are produced by stationary metallic objects in the environment. Compared with static distortions, in this paper a relatively dynamic situation is considered where the distortion is not constant with time. However, the location of the metallic objects is reflected in the outputs of the receiver so that the distortion can be compensated. This type of distortions, which is called 'quasi-static distortion' in this paper, is common in an ART. Compensation of quasi-static distortion is more complicated than that of static distortion and has not been mentioned in past publications. Some new compensation methods for quasi-static distortion will be introduced here. The results demonstrate that the methods are capable of significantly reducing quasi-static distortions.

[Water quality of closed polyculture of penaeid shrimp with tilapia and constricted tagelus]

A variety of water quality parameters were monitored in enclosures for the polyculture of penaeid shrimp with tilapia and constricted tagelus. The result showed that the environment of the polyculture systems was better than that of monoculture one. The fluctuation of DO in the water of polyculture enclosures was less violent, and their lowest values were obviously higher than those in monoculture ones. The value of COD and the number of bacteria in the water of polyculture enclosures were significantly lower than those in monoculture ones(t-test, alpha < 0.05), showing that the amount of organic matter in the water of polyculture systems was less than that in monoculture one. The biomass of plankton and the concentration of chlorophyll-a in the polyculture enclosures were also lower, showing that the suppression of the filtering animals to the plankton was obvious. The accumulation of N and P in the sediment of polyculture enclosures was 39.76% and 51.26%, lower than those of monoculture ones, respectively; and the number of bacteria in the sediment was 7.63% lower. Therefore, it is obvious that closed culture system can greatly decrease the effluent to the coastal waters caused by the pond culture industry, and decrease the pollution to the coastal waters.

Regulation of Ras signaling specificity by protein kinase C

Ras proteins have the capacity to bind to and activate at least three families of downstream target proteins: Raf kinases, phosphatidylinositol 3 (PI 3)-kinase, and Ral-specific guanine nucleotide exchange factors (Ral-GEFs). We have previously shown that the Ras/Ral-GEF and Ras/Raf pathways oppose each other upon nerve growth factor stimulation, with the former promoting proliferation and the latter promoting cell cycle arrest. Moreover, the pathways are not activated equally. While the Ras/Raf/Erk signaling pathway is induced for hours, the Ras/Ral-GEF/Ral signaling pathway is induced for only minutes. Here we show that this preferential down-regulation of Ral signaling is mediated, at least in part, by protein kinase C (PKC). In particular, we show that PKC activation by phorbol ester treatment of cells blocks growth factor-induced Ral activation while it enhances Erk activation. Moreover, suppression of growth factor-induced PKC activation enhances and prolongs Ral activation. PKC does not influence the basal activity of the Ral-GEF designated Ral-GDS but suppresses its activation by Ras. Interestingly, Ras binding to the C-terminal Ras binding domain of Ral-GDS is not affected by PKC activity. Instead, suppression of Ral-GDS activation occurs through the region N terminal to the catalytic domain, which becomes phosphorylated in response to phorbol ester treatment of cells. These findings identify a role for PKC in determining the specificity of Ras signaling by its ability to differentially modulate Ras effector protein activation.

[Measurement of microvessel density in laryngeal carcinoma and its clinical significance]

OBJECTIVE

To determine the microvessel density (MVD) in laryngeal carcinoma and its clinical significance.

METHOD

Thirty-eight tumor specimens were selected from laryngeal cancer patients from January, 1994 to March, 1996. Histological sections of the tumors were stained immunohistochemically for factor VIII. Using light microscopy, we counted microvessels per 400 x field in the most active areas of tumor angiogenesis.

RESULT

1. The tumor blood vessels, composed of only one layer of endothelium were mainly distributed heterogeneously in the interstitial tissue of laryngeal carcinoma with irregular lumen, poorly developed structure. 2. The MVD in the cancer tissues were statistically higher than that in peritumoral tissues (P < 0.01). 3. The MVD in the cancer tissues in group of patients with metastasis to cervical lymphonodes were statistically higher than in group without metastasis (P < 0.01), the MVD in the cancer tissues in group of advanced cases (III, IV stages) were statistically higher than that in group of early cases (I, II stages, P < 0.01). 4. There was no statistically difference in MVD in the cancer tissue between supraglottic and glottic laryngeal carcinoma patients (P > 0.05). 5. There was no statistically difference in MVD in the cancer tissue among the G1, G2 and G3 group (P > 0.05).

CONCLUSION

The laryngeal cancer blood vessels have some characteristics that don't appear in normal vessels. It is suggested that tumor angiogenesis can promote tumor growth and metastasis and MVD may be a new prognostic indicator of laryngeal carcinoma.

The development of a potential single photon emission computed tomography (SPECT) imaging agent for the corticotropin-releasing hormone receptor type

A high-affinity radioligand for CRHR1 has been prepared that can serve as a template for the development of SPECT imaging agents. The 5-chloro-N-cyclopropylmethyl-N-(2,6-dichloro-4-iodophenyl)-2-methyl-N-propylpyrimidine-4,6-diamine (6b, Ki = 14 nM), and the corresponding 4-bromophenyl analogue (6a, Ki = 21 nM), were synthesized in four steps from compound 3.

Lymphocytes and perforin expression in endometrium during the menstrual cycle

OBJECTIVE

To study the lymphocytes, perforin protein and mRNA expression in endometrium of different phases in the menstrual cycle and to explore the regularity and role of the lymphocytes and perforin in the reproductive system.

METHODS

Immunohistochemical and in situ hybridization techniques were employed to demonstrate the population, phenotype and mediator (perforin) of lymphocytes in the proliferative and secretory endometrium.

RESULTS

In different phases of the endometrium, there were very few CD3+ typical T lymphocytes, CD4+ helper lymphocytes and CD8+ suppressor/cytotoxic T lymphocytes, while CD56+ lymphocyte (also named NK-like cell) were abundant. CD56+ lymphocytes were absent in postmenopausal endometrium. A double immunohistochemical labelling method demonstrated the co-expression of perforin protein and CD56 antigen of cells in different phases of the endometrium. Quantitative analysis of CD56+ lymphocytes and perforin-positive cells increased in number from the proliferative to the secretory endometrium (P < 0.05). In situ hybridization analysis showed that perforin mRNA positive cells formed islands in proliferative endometrial stroma, but were scattered in secretory endometrium. There was difference between perforin gene expression and protein expression in the proliferative endometrium.

CONCLUSIONS

Lymphocytes and perforin expression in the endometrium at different phases of the menstrual cycle are specific and may play an important role in the reproductive system. They may exert a positive influence on embryo implantation and be involved in endometrial stroma breakdown during menstruation.

p130Cas regulates the activity of AND-34, a novel Ral, Rap1, and R-Ras guanine nucleotide exchange factor

We previously identified a novel murine protein, AND-34, with a carboxyl-terminal domain homologous to Ras family guanine nucleotide exchange factors (GEFs), which bound to the focal adhesion docking protein p130(Cas). Work by others has implicated both the human homologue of AND-34, BCAR3, and human p130(Cas), BCAR1, in the resistance of breast cancer cells to the anti-estrogen tamoxifen. Here we report that AND-34 displays GEF activity on RalA, Rap1A, and R-Ras but not Ha-Ras GTPases in cells. In contrast to several other Ral-GEFs, the Ral GEF activity of AND-34 is not augmented by constitutively active Ha-Ras(Val-12), consistent with the absence of a detectable Ras-binding domain. Efficient binding to AND-34 required both the Src-binding domain and a flanking carboxyl-terminal region of p130(Cas). The p130(Cas)-binding site mapped to a carboxyl-terminal sequence within the AND-34 GEF domain. Overexpression of p130(Cas), but not an AND-34-binding mutant of p130(Cas), inhibited the Ral GEF activity of co-transfected AND-34. This work identifies a new potential function for p130(Cas) and a new regulatory pathway involved in the control of Ral, Rap, and R-Ras GTPases that may participate in the progression of breast cancer cells to tamoxifen resistance.

Upregulation of tyrosine hydroxylase and downregulation of choline acetyltransferase in lead-exposed PC12 cells: the role of PKC activation

The effects of lead (Pb) on the expression of tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT) were compared in relation to Pb-activation of cPKC in the PC12 cells. Exposure to 0.53 microM Pb (0.1094 ppm) increased TH but reduced ChAT activity and mRNA levels. The increase of TH activity was detectable as early as 0.5 h of exposure, reached a maximum 150% of control after 2 h, and then diminished to a steady state 135% of control between 12 and 48 h of exposure. The decrease of ChAT activity was first detectable after 2 h of Pb exposure, reached a 45% reduction after 6 h, and remained stable thereafter through 48 h of exposure. PKC activity increased 200% after 2 h and then reverted to control levels by 48 h of Pb exposure. The increase of TH activity after 2 h but not 48 h of exposure exceeded that of its mRNA. PKC inhibitor Rö32-0342 suppressed TH activity increase after 2 h of Pb exposure by 80% without affecting TH mRNA. The decrease of ChAT activity correlated with the reductions in steady-state ChAT mRNA levels at 2 and 48 h of Pb exposure and Rö32-0342 had no effect on the Pb-induced decrease of either ChAT activity or mRNA. These results demonstrate that Pb alters TH and ChAT expression in PC12 cells in a reciprocal manner, i.e., upregulates the former but downregulates the latter. PKC is not involved in Pb-induced downregulation of ChAT but does mediate the early phase of Pb-induced augmentation of TH activity, presumably through postranslational modification (phosphorylation) of the enzyme. However, this effect is short-lived due to downregulation of PKC in the course of prolonged (48 h) Pb exposure. It is concluded that, in the course of prolonged exposure, both upregulation of TH and downregulation of ChAT reflect primarily the effects of Pb at the level of gene expression through mechanisms that are not related to Pb activation of PKC.

[An analysis of precision and accuracy of the phonocardiogram exercise test]

Phonocardiogram exercise testing (PCGET) is a recently developed method to evaluate cardiac contractility and the cardiac reserve of patients with heart disease and of healthy subjects. In order to test the reliability of PCGET method, the present author conducted a study on its precision and accuracy. Thirty volunteers underwent PCGET. When different examiners measured the S1 amplitude in the same cardiac cycle of the same subject, the data obtained by examiner A were: x +/- s = 5.05 +/- 0.0451; the data obtained by examiner B were: x +/- s = 4.95 +/- 0.0346, F = 1.699, P > 0.05. When different examiners measured the same cardiac cycle of the same subject, the data obtained by examiner A were: x +/- s = 0.789 +/- 0.0018; the data obtained by examiner B were: x +/- s = 0.787 +/- 0.0017, F = 1.167, P > 0.05. The results suggest that PCGET is a nonivasive, convenient, and inexpensive technique to quantitatively evaluate cardiac reserve for abnormal or normal persons.

[Selection and characterization of human antibodies against vascular endothelial growth factor from human phage display antibody library]

OBJECTIVE

To select anti-VEGF (vascular endothelial growth factor) antibodies (Fab fragments) from human phage display antibody library and to identify their specification and activities.

METHODS

Human immunoglobulin heavy chain and light chain genes were separately amplified by RT-PCR from human peripheral lymphocytes using family specific primers and signal sequences of immunoglobulin. Human antibody library was constructed by phage display technology, and phage Fab antibodies to VEGF were screened from this library. ELISA, Western blot and (3)H-thymidine incorporation assays were used for the specification and neutralization activities of these Fab antibodies. Sequencing analysis was carried out for further identification of the antibodies.

RESULTS

The repertoire of human phage display Fab library was 1.5 x 10(8). After 4 round panning with VEGF(121), 280 clones were checked for their binding activities with ELISA and 12 clones could bind to VEGF(121) specifically. Western blot demonstrated that bacterially expressed soluble Fab could specifically recognize VEGF. Results of (3)H- thymidine incorporation showed that one clone of soluble Fab could neutralize the mitogenic activity of VEGF(165) on HUVEC. Sequencing analysis showed that the obtained V(H) gene belonged to human VH6 subgroup and the light chain was VJC rearranged human VL4 gene.

CONCLUSIONS

Human anti-VEGF antibodies can be obtained from human phage display library, which provides a basis for preparation of high affinity human anti-VEGF monoclonal antibodies through antibody engineer technique.

Relation between left ventricular geometric alteration and extracardiac target organ damage in hypertensive patients

To study the relation between left ventricular geometric alteration and extracardiac target organ damage in hypertensive patients. A retrospective study of 298 patients with essential hypertension was performed. Left ventricular mass index (LVMI) and relative wall thickness (RWT) were calculated using echocardiographic data. Patients were divided into four groups based on their left ventricular geometric pattern as determined using LVMI and RWT. Each of the four left ventricular geometric patterns was associated with a different degree of extracardiac organ damage. In multivariate analysis, LVMI and RWT showed strong, significant correlation to retinal changes and increases in serum creatinine levels, respectively. Alteration of left ventricular geometry resulted in an increase in the degree of extracardiac target organ damage. Echocardiographic classification of left ventricular geometry can further stratify hypertensive patients according to risk, and possibly according to the indications for intensive treatment.

Developmental stage-dependent protective effect of NGF against lead cholinotoxicity in the rat septum

The ability of nerve growth factor (NGF) to ameliorate developmental cholinotoxicity of inorganic lead (Pb) for the septal neurons was investigated by making intracerebroventricular injections of single doses of 30 microg 2.5S NGF into maternally lead-exposed suckling rats on postnatal days P2, P4, P11, or P18. Administration of NGF on P4 or later induced septal choline acetyltransferase (ChAT) activity to the same relative extent in both Pb-exposed as in control rats but failed to reverse the net reductions of ChAT activity induced by Pb. In contrast, injection of NGF at P2 completely restored ChAT activity in Pb-exposed pups to control levels by preventing the loss of ChAT-immunoreactive cells in the septum. It is concluded that although NGF retains the capacity to upregulate ChAT throughout the period of Pb exposure, it protects against the Pb-induced loss of septal cholinergic neurons only when applied within the critical period of Pb-vulnerability between postnatal days 2 and 4.

[Isolation and identification of HN-98 strain of spotted fever group rickettsiae]

OBJECTIVE

One strain of rickettsiae was isolated from a patient with unknown fever from Qiongzhong county in Hainan Province in 1998, using embryonated hen eggs and proved to be the member of rickettsiae by the methods of morphology. It was named HS-98 strain after the name of the place and the year it was isolated.

METHODS

The isolate was identified by methods of Microcomplement fixation assay and OCR/RFLP and compared with known species and strains of SFGR by DNA polymerase chain reaction and DNA polymerase chainreaction and was followed by restriction endonuclease fragment length polymorphism analysis.

RESULTS

Results demonstrated that HN-98 strain was antigenically and genotypically identical to R. sibirica 246.

CONCLUSION

The results suggested that there existed natural foci of spotted fever in Qiongzhong Area of Hainan Province.