[Vitrectomy combined with scleral buckling for the treatment of complicated retinal detachment]

PURPOSE

To raise operative successful rate of complicated retinal detachment, we used the methods of vitrectomy combined with scleral buckling for the treatment of complicated retinal detachment.

METHODS

The operative methods included: scleral buckling, vitrectomy, membrane peeling, intraocular and extraocular drainage, gas and silicone oil tamponade.

RESULT

Being followed up for 1-16 months, 22 eyes got anatomic reattachment in 29 eyes, the operative successful rate was 75.8%; 15 eyes were injected with silicone oil intraocular tamponade, with 12 eyes getting reattachment. The successful rate was 80%.

CONCLUSION

Since the vitreous surgery is used, it is possible for the treatment of complicated retinal detachment, the operative successful rate can be raised. The technique of membrane peeling and intraocular tamponade was very important. Silicone oil has been accepted by more and more ophthalologists in the world, which acts as an effective material of intraocular tamponade.

[Des-Tyr1]dynorphin A-(2-17) has naloxone-insensitive antinociceptive effect in the writhing assay

The dynorphin family of peptides stands out among the opioids in that its members are not antinociceptive after central administration in the common antinociceptive assays. In addition, reports of spinal antinociception have been conflicting. We have tested the antinociceptive activity of i.v. dynorphin A-(1-13) in the writhing assay and have found it to be very potent, with an ED50 of 1.0 (0.99-1.02) mumol/kg. Remarkably, [des-tyr1]dyn A-(2-17) was equally active with an ED50 of 1.1 (0.99-1.20). This activity was also retained by several smaller, non-opioid dynorphin A fragments and was not affected by the presence of either 50 mumol/kg naloxone or 20 mumol/kg Nor-BNI. Further, ED50 values were not different in morphine-dependent mice. The peak effect of dyn A-(1-13) and A-(2-17) was observed 5 min after administration and the effect of dyn A-(1-13) or dyn A-(2-17) was still measurable 1 hr after i.v. administration with a 5- to 6-fold increase in ED50 at this time. The ED50 values after i.c.v. and i.t. administration of dyn A-(1-13) were similar to those reported previously. Dyn A(2-17) was also effective by these routes with ED50 values not significantly different from those of dyn A-(1-13). Both dyn A-(1-13) and A-(2-17) were also active when injected i.p., whereas ED50 values increased substantially after s.c. administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Cellubrevin is a resident protein of insulin-sensitive GLUT4 glucose transporter vesicles in 3T3-L1 adipocytes

Insulin stimulates glucose transport in muscle and fat cells by inducing translocation of GLUT4 glucose transporters from a storage site to the cell surface. The mechanism of this translocation and the identity of the storage site are unknown, but it has been hypothesized that transporters recycle between an insulin-sensitive pool, endosomes, and the cell surface. Upon cell homogenization and fractionation, the storage site migrates with light microsomes (LDM) separate from the plasma membrane fraction (PM). Cellubrevin is a recently identified endosomal protein that may be involved in the reexocytosis of recycling endosomes. Here we describe that cellubrevin is expressed in 3T3-L1 adipocytes and is more abundant in the LDM than in the PM. Cellubrevin was markedly induced during differentiation of 3T3-L1 fibroblasts into adipocytes, in parallel with GLUT4, and the development of insulin regulated traffic. In response to insulin, the cellubrevin content decreased in the LDM and increased in the PM, suggesting translocation akin to that of the GLUT4 glucose transporter. Vesicle-associated membrane protein 2 (VAMP-2)/synaptobrevin-II, a protein associated with regulated exocytosis in secretory cells, also redistributed in response to insulin. Both cellubrevin and VAMP-2 were susceptible to cleavage by tetanus toxin. Immunopurified GLUT4-containing vesicles contained cellubrevin and VAMP-2, and immunopurified cellubrevin-containing vesicles contained GLUT4 protein, but undiscernible amounts of VAMP-2. These observations suggest that cellubrevin and VAMP-2 are constituents of the insulin-regulated pathway of membrane traffic. These results are the first demonstration that cellubrevin is present in a regulated intracellular compartment. We hypothesize that cellubrevin and VAMP-2 may be present in different subsets of GLUT4-containing vesicles.

Dynorphin A modulates acute and chronic opioid effects

A single dose of dynorphin A-(1-13) [dyn A(1-13)] is effective in suppressing the expression of opioid withdrawal and tolerance in morphine-dependent mice. In addition, this modulatory activity is retained by the corresponding non-opioid [des-Tyr1]-dynorphin A peptide [dynA(2-17)]. We have further investigated the non-opioid nature of this activity by comparing the efficacies of dyn A(1-13) and (2-17) under different experimental protocols with a variety of dosing regimens. The effect of dyn A(1-13) on withdrawal and tolerance expression was dose-dependent and could be enhanced by repeated dosing. Thus, the ED50 of naloxone to precipitate withdrawal jumping was increased 1.8-fold when morphine-dependent mice were treated with 4.2 mumol/kg dyn A(1-13) on the fourth day after pellet implantation and 2.4-fold on the sixth day with continued daily dyn A(1-13) treatment. The maximal effect was observed on day 6 when the ED50 of mice treated with 8.4 mumol/kg of dyn A(1-13) was increased nearly 6-fold over that of saline controls. Dyn A(2-17) proved to be nearly as effective as dyn A(1-13).

Induction of geranyl pyrophosphate pyrophosphatase activity by cholesterol-suppressive isoprenoids

Diets supplemented (1 mmol/kg) with thymol, carvacrol, and beta-ionone significantly decreased the serum cholesterol levels of cockerels. These mevalonate-derived end products of plant secondary metabolism (isoprenoids) had no impact on two cytosolic prenyl alcohol (and ethanol) dehydrogenase activities; each treatment increased microsomal geranyl pyrophosphate pyrophosphatase activity by greater than twofold. The structural diversity of the isoprenoids which suppress cholesterol synthesis may be reconciled by their ability to increase pyrophosphatase activity, thus leading to the production of the endogenous, post-transcriptional regulator of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity.

Three-dimensional reconstruction of the rubrocerebellar premotor network of the turtle

Neuroanatomical studies have demonstrated that the organization of the reptilian rubrocerebellar limb premotor network is similar to that of mammals. This network is composed of prominent recurrent connections among the red nucleus, lateral cerebellar nucleus and lateral reticular nucleus. In this paper the rubrocerebellar system of the turtle was three-dimensionally reconstructed to permit detailed examination of its anatomical organization. Each nucleus and its major efferent pathway was imaged and reconstructed from separate anatomical cases. Section images were used to draw tissue boundaries, mark cell positions and locate axonal trajectories. For each nucleus, drawings of section images containing labeled cells were stacked in the rostrocaudal direction using anatomical landmarks, and a graphic model of the surface was constructed using the method of triangulation. An ellipsoid of equal concentration was computed for each nucleus to ascertain their three-dimensional boundaries and location within the brainstem. To examine the entire rubrocerebellar network, a template of the turtle brainstem and cerebellum was constructed. The component nuclei of the rubrocerebellar network and their axonal projections were then spatially warped onto the template reconstruction on a section by section basis. The final three-dimensional reconstruction of the turtle rubrocerebellar limb premotor network could be rotated in space, allowing proper visualization of the anatomical details of this system. Furthermore, we were able to mathematically section through the reconstruction to obtain brainstem slices with differing orientations and thickness.

P-glycoprotein expression in primary breast cancer

In a retrospective study, liquid nitrogen preserved specimens from 50 women with primary breast cancer, who underwent surgery at the Beijing Institute for Cancer Research between June, 1986 and September, 1988, were investigated. All patients under this study were staged in TNM II or later, involved with axillary lymph node metastasis, and treated with systemic postoperative adjuvant chemotherapy. The median length of follow-up was 69 months. The expression of P-glycoprotein was investigated by means of immunohistochemistry, using a monoclonal antibody C219 specifically against P-glycoprotein and avidin-biotin peroxidase method. Positive staining for P-glycoprotein was found in 23 (46%) of the 50 patients. The P-glycoprotein expression negative group fared better than the group that was P-glycoprotein positive in overall survival curves (p = 0.0008, by the generalized Wilcoxon test). The prognostic effect of P-glycoprotein expression remained statistically significant (p = 0.0007) after adjustment by multivariate analysis (Cox's model) for other prognostic factors. It is demonstrated that P-glycoprotein expression is a significant and independent predictor of postoperative survival in breast cancer patients. The results of the present study suggest that P-glycoprotein expression might also influence the biological behavior of breast cancers.

Phosphorylation of the C-terminal domain of RNA polymerase II by the extracellular-signal-regulated protein kinase ERK2

Rat ERK2, an extracellular-signal-regulated protein kinase family member, phosphorylates RNA polymerase II in vitro. Phosphorylation occurs within the heptapeptide repeats of the C-terminal domain of the largest subunit, in a region important for regulation of transcriptional activity. Analysis of deletion mutants and synthetic peptides showed that ERK2 phosphorylation occurs at multiple serine residues throughout the C-terminal domain, with no marked preference for consensus repeats versus naturally occurring variants. Our results are consistent with the idea that protein kinases in the extracellular-signal-regulated protein kinase family regulate transcription by direct phosphorylation of RNA polymerase II, but do not support a model where particular portions of the C-terminal domain are special targets of ERK phosphorylation.

Expression of vesicle-associated membrane protein 2 (VAMP-2)/synaptobrevin II and cellubrevin in rat skeletal muscle and in a muscle cell line

Molecular studies have identified a family of synaptic vesicle-associated membrane proteins (VAMPs, also known as synaptobrevins) which have been implicated in synaptic vesicle docking and/or fusion with plasma membrane proteins. Here we demonstrate the expression of two members of this family, VAMP-2/synaptobrevin II and cellubrevin, in skeletal muscle, a tissue with both constitutive and regulated membrane traffic. The 18 kDa VAMP-2 polypeptide was detected in purified membrane fractions from adult skeletal muscle and from L6 myotubes in culture, demonstrating that the presence of this protein in the isolated muscle membrane fractions is not the result of contamination by ancillary tissues such as peripheral nerve. Furthermore, skeletal muscle and the muscle cell line also expressed cellubrevin, a VAMP-2 homologue of 17 kDa; which is much less abundant in brain cells. Both VAMP-2 and cellubrevin were preferentially isolated in membrane fractions rich in plasma membranes, and were less concentrated in light microsomes and other internal membrane fractions of mature muscle or muscle cells in culture. Interestingly, both VAMP-2 and cellubrevin were much more abundant in the differentiated L6 myotubes than in their precursor myoblasts, suggesting that they are required for functions of differentiated muscle cells. The identity of both polypeptides was further confirmed by their susceptibility to proteolysis by Clostridium tetanus toxin. Expression of these products was further established by the presence of mRNA transcripts of VAMP-2 and cellubrevin, but not of VAMP-1, in both skeletal muscle and L6 myotubes. In contrast, other synaptic vesicle and docking/fusion components were undetectable, such as VAMP-1, SNAP25 and syntaxin 1A/1B, as were synaptophysin and synapsin Ia/Ib, proteins which are believed to be involved in sensing the signal for neuronal exocytosis. It is concluded that VAMP-2 and cellubrevin are expressed in skeletal muscle cells and may each participate in specific processes of intracellular membrane traffic.

[Chemical constituents of flower of David lily]

Three compounds were isolated from the flower of Lilium devidii. On the basis of chemical reaction, UV, MS, 1HNMR and 13CNMR spectral data, they were identified as beta-sitosterol, stigmasterol and emodin. These compounds are obtained from the plant for the first time.

[Therapeutic effectiveness of zuzhongping on patients with arteriosclerostic cerebral infarction]

Forty-six patients with acute arteriosclerostic cerebral infarction were randomly divided into two groups: control group and treatment group. Each of them included 23 patients respectively. The patients in the control group were given Dextran-40 but the ones in the treatment group were given the mixture of Zuzhongping. The course of treatment was 3 weeks. It was found that there was a significant difference (P < 0.01) in the score percentage, before and after treatment of neurological defects, between the control group and the treatment group, and the former (29.70 +/- 33.52) was much lower than the latter (45.40 +/- 27.60). The total curative rate of the treatment group (87.0%, 20/23) was significantly higher than that of the control group (60.9%, 14/23). There was an obviously prolonged KPTT (kaolin partial thromboplastin time) value and a decreased Fb (fibrinogen) level in the treatment group. Before treatment they were 32.43 +/- 4.03 sec and 6.18 +/- 1.77 g/L respectively, but after treatment, 52.96 +/- 10.50 sec and 4.5 +/- 0.95 g/L respectively. The authors suggest that the significant therapeutic efficacy of Zuzhongping in the patients with acute arteriosclerostic cerebral infarction is related to its action of anticoagulation, modification of PGI2 and TXA2 level in the body, decreased blood Fb level, hyperglycemia, etc.

Involvement of mu opioid receptors of periaqueductal gary (PAG) in acupuncture inhibition of noxious blood pressure response in rabbits

Strong electric shock stimulation of the rabbit front paw elicited a pressor blood pressure response regarded as noxious response. Ligands of mu opioid receptors were microinjected into the PAG to observe their effects on acupunture inhibition of the pressor response. (1) Ohmefentanyl (OMF), a mu agonist, significantly attenuated the pressor response. Mu antagonist TCTAP greatly enhanced the pressor response. (2) Electroacupuncture (EA) significantly inhibited the pressor response, the inhibition being readily reversed by TCTAP. The response after TCTAP was significantly greater than that of the control before EA. The results suggest that noxious stimulation is able to activate the mu opioid receptor of the PAG to modulate the noxious response and EA is able to enhance the activation.

Beneficial effect of an ACTH-(4-9) analog (Org2766) in the treatment of experimental cortex lesion in rats

This paper reports that lesions of the medial frontal cortex (MFC) caused behavioral deficit in rats and that this deficit could be attenuated by a well formulated treatment with Org2766, an analog of ACTH-(4-9). Wistar rats were distributed in 3 groups: MFC lesion treated with saline (M-N); MFC lesion treated with Org2766 (M-O); and sham-operation treated with saline (S). Repeated Org2766 or saline injection commenced from the day of surgery and lasted for 13 days. After surgery, the rats were trained in a passive avoidance task and then in an active avoidance task. MFC lesions were found to be strongly associated with behavioral deficits. The M-N group rats displayed poor retention of the passive avoidance response and showed much slower learning of the active avoidance task as compared to S group rats. The result showed that chronic Org2766 administration improved the behavioral performance of both tasks in MFC lesioned rats. The also revealed that the superoxide dismutase (SOD) activity was significantly increased in the M-O group as compared to the M-N group 15 days after surgery. The possible mechanisms related to the beneficial effect of Org2766 on cortex damage are discussed.

Body mass, fat distribution and cardiovascular risk factors in a lean population of south China

The associations of body mass index and abdominal adiposity, represented by an elevated waist/hip circumference ratio, with cardiovascular risk factors were examined in men and women, aged 28-69 years, from urban and rural areas of Guangzhou, China. Mean body mass index ranged from 20.1 to 21.9 kg/m2 across the four sex- and area-groups. Mean waist/hip ratio was 0.84 in men and 0.80 in women. After accounting for age and body mass index, waist/hip ratio was associated negatively (p < 0.05) with fasting serum HDL cholesterol (both sexes), and positively with serum triglycerides (both sexes), total and LDL cholesterol (men only), uric acid (both sexes), glucose (women only), and mean systolic blood pressure (women only). Body mass index was associated in a similar direction with most of these risk factors. These data confirm that abdominal adiposity is independently associated with cardiovascular disease risk factors, even in a lean Asian population.

Release of gonadotropin-releasing hormone (GnRH) from the medio-basal hypothalamus induced by electroacupuncture in conscious female rabbits

In electroacupuncture (EA) treatment, successful induction of ovulation is usually accompanied with the facilitation of pulsatile secretion of gonadotropin. The present work studied the release of GnRH from the mediobasal hypothalamus (MBH) using push-pull perfusion technique in conscious New Zealand female rabbits before, during and after EA stimulation. EA (4Hz, 5mA, 30 min) of Guanyuan (Ren 4), Zhongji (Ren 3), bilateral Sanyinjiao (SP 6) and Zigong (Extra 16) was given at the end of the 1st, 3rd and 5th hour during 6 hours' perfusion (EA group, n = 6). Cupric acetate (CuAC) was given (1%, 0.9 ml, i.v.) at the end of the 1st hour perfusion (CuAC group, n = 5) as a control since it is known as a stimulant for the release of GnRH. Rabbits in the control group (n = 4) were under the same perfusion condition except with no CuAC injection or EA stimulation. It was found that GnRH level was elevated immediately and significantly (4.64 +/- 0.98 v.s. 2.08 +/- 0.01 pg/ml, P < 0.05) after EA stimulation. In the CuAC group, GnRH level was also significantly elevated (3.84 +/- 0.37 v.s. 2.08 +/- 0.001 pg/ml, P < 0.05) one hour after CuAC injection. In addition, corpus lutein were observed both in the EA group (2/6) and the CuAC group (5/5). No similar changes were found in the control group. The data suggest that EA is capable of facilitating GnRH release from the MBH.

Mu opiate receptor antagonist blocks electroacupuncture inhibition on noxious blood pressure response in rabbits

A pressor blood pressure response was elicited by strong electric shock stimulation of the front paw in rabbits anesthetized with chloralose and urethane, immobilized by gallamine triethiodide and maintained by artificial ventilation. The pressor response showed a gradual decline in 3-4 successive trials. Naloxone or TCTAP, a specific mu receptor antagonist, administered intraventricularly (icv) at that time could facilitate the pressor response (n = 8, P < 0.02; n = 7, P < 0.01), suggesting the involvement of mu receptors in the declination of the pressor response. Electroacupuncture could inhibit the pressor response (n = 7, P < 0.01), and the inhibition was readily blocked by TCTAP (n = 7, P < 0.01). No obvious changes were observed in the normal saline control group. The results suggest that acupuncture is able to inhibit the pressor response via the activation of the opioid peptidergic system, of which the mu receptor is an important component.

High-performance liquid chromatographic separation of ondansetron enantiomers in serum using a cellulose-derivatized stationary phase and solid-phase extraction

R(-)-Ondansetron and S(+)-ondansetron in human serum were resolved and quantified using a stereospecific HPLC method. Each enantiomer and the internal standard prazosin were isolated from serum using a solid-phase extraction procedure on a cyanopropyl column. Recoveries of 97, 96 and 88% were obtained for the R(-)-enantiomer, the S(+)-enantiomer, and the internal standard, respectively. A cellulose-based chiral analytical column (Chiralcel OD) was used with a mobile phase consisting of hexane-95% ethanol-2-propanol-acetonitrile (65:25:10:1, v/v). Linear calibration curves were obtained for each enantiomer in serum in the concentration range 10-200 ng/ml. The limit of quantitation of each enantiomer was 10 ng/ml. The detection limit for each enantiomer in serum using UV detection at 216 nm was 2.5 ng/ml (signal-to-noise ratio of 3).

Transformation-sensitive cells in G2/M-phase are not promoted by TPA following 137Cs gamma-rays

Mouse C3H 10T1/2 cells are most sensitive to radiation-induced neoplastic transformation in the G2/M-phase of the cell cycle. When synchronized 10T1/2 cells were exposed to phorbol 12-myristate 13-acetate (TPA) after irradiation, transformation of cells not in the transformation-sensitive window was enhanced, but transformation of cells already in the transformation-sensitive window was not. Earlier work showed that (a) TPA enhances the frequency of transformation of both high and low dose-rate gamma-irradiated cells by about the same factor, but that (b) TPA enhances the transformation of cells exposed to low dose-rate fission spectrum neutrons appreciably less than cells exposed to high dose-rate fission spectrum neutrons. The latter observation is consistent with the inability of TPA to promote cells in the transformation-sensitive window and with the role of such cells in enhancing transformation by protracted doses of neutrons. The data provide a cellular basis for studying the biochemical/molecular aspects of TPA promotion in vitro.

Liquid chromatographic separation of praziquantel enantiomers in serum using a cellulose-based chiral stationary phase

R(-) and S(+) praziquantel (PZQ) in human serum were resolved and quantified using a stereospecific LC method. Each enantiomer and the internal standard 2-methylamino-5-chlorobenzophenone were isolated from serum using a solid-phase extraction procedure on a cyanopropyl column. Recoveries of 98.8, 93.3 and 35.4% were obtained for R(-) PZQ, S(+) PZQ, and the internal standard, respectively. A cellulose-based chiral analytical column (Chiralcel OD) was used with a mobile phase consisting of hexane-2-propanol (70:30, v/v). Linear calibration curves were obtained in the concentration range 50-1000 ng ml-1 for each enantiomer in serum. The detection limit for each enantiomer in serum using UV detection at 212 nm was 5 ng ml-1 (S/N = 3). The limit of quantitation of each enantiomer was 25 ng ml-1.

Lignification in cell suspension cultures of Pinus taeda. In situ characterization of a gymnosperm lignin

Pinus taeda suspension cultures grown in medium containing 2,4-dichlorophenoxyacetic acid showed only primary cell wall formation and essentially no lignification, as determined by histochemical, ultrastructural, chemical, and NMR spectroscopic analyses. However, these cultures maintained a functional phenylpropanoid pathway as demonstrated by formation of the lignans (-)-matairesinol and (-)-pinoresinol. Administration of [1-13C]Phe to these cultures, followed by solid-state carbon-13 NMR spectral analysis of their cell walls, demonstrated that the phenylalanine incorporated into the cell wall matrix was primarily as protein, rather than lignin. Successive transfer of the 2,4-dichlorophenoxyacetic acid-grown cultures to alpha-naphthaleneacetic acid-containing medium induced cell wall thickening concomitant with lignification. The presence of lignin was confirmed by histochemical, ultrastructural, chemical, biochemical, and NMR spectroscopic analyses. Specific labeling of the lignin polymer in situ with [1-13C]-, [2-13C]-, and [3-13C]Phe and analysis of the cell wall preparations by solid-state carbon-13 NMR spectroscopy permitted the first direct determination of the in situ bonding patterns in a gymnosperm lignin. Several dominant interunit linkages were observed, including beta-O-aryl, furanofuran, phenylcoumarin, and phenolic-linked monolignols, consistent with those predicted but hitherto not proven. Finally, milled wood lignin derivatives prepared from these 13C-specifically enriched lignin tissues gave a relatively high fidelity copy of the native lignin.

[An experimental study on accelerating regeneration of meniscus with synovial flap implant in the rabbit knee]

Twenty-three rabbits were used in this study. In each animal the right knee was used for experimental group in which the synovial flap was implanted in after meniscectomy and the left knee for control group, in which only meniscectomy was done. Samples were collected 3, 6, 12, and 24 weeks after operation. The regenerated meniscus in two groups were evaluated grossly. Histologically by light microscopy, and subcellularly by transmission electron microscopy. It was showed that the regenerated meniscus of the experimental group were better than those of the control group both morphologically and qualitatively. In the experimental group fibrocartilage cells appeared 6 weeks after operation, cartilage cells became more mature at 12 weeks, and articular cartilage was normal at 24 weeks. The result shows that the synovial flap implant obviously accelerates the meniscus regeneration and has an affect on prevention articular cartilage from degenerating.

Loss of function of Saccharomyces cerevisiae kinesin-related CIN8 and KIP1 is suppressed by KAR3 motor domain mutations

The kinesin-related products of the CIN8 and KIP1 genes of Saccharomyces cerevisiae redundantly perform an essential function in mitosis. The action of either gene-product is required for an outwardly directed force that acts upon the spindle poles. We have selected mutations that suppress the temperature-sensitivity of a cin8-temperature-sensitive kip1-delta strain. The extragenic suppressors analyzed were all found to be alleles of the KAR3 gene. KAR3 encodes a distinct kinesin-related protein whose action antagonizes Cin8p/Kip1p function. All seven alleles analyzed were altered within the region of KAR3 that encodes the putative force-generating (or "motor") domain. These mutations also suppressed the inviability associated with the cin8-delta kip1-delta genotype, a property not shared by a deletion of KAR3. Other properties of the suppressing alleles revealed that they were not null for function. Six of the seven were unaffected for the essential karyogamy and meiosis properties of KAR3 and the seventh was dominant for the suppressing trait. Our findings suggest that despite an antagonistic relationship between Cin8p/Kip1p and Kar3p, aspects of their mitotic roles may be similar.

PcnB is required for the rapid degradation of RNAI, the antisense RNA that controls the copy number of ColE1-related plasmids

The replication of ColE1-related plasmids is controlled by an unstable antisense RNA, RNAI, which can interfere with the successful processing of the RNAII primer of replication. We show here that a host protein, PcnB, supports replication by promoting the decay of RNAI. In bacterial strains deleted for PcnB a stable, active form of RNAI, RNAI*, which appears to be identical to the product of 5'-end processing by RNAase E, accumulates. This leads to a reduction in plasmid copy number. We show, using a GST-PcnB fusion protein, that PcnB does not interfere with RNAI/RNAII binding in vitro. The fusion protein, like PcnB, has polyadenylating activity and is able to polyadenylate RNAI (and also another antisense RNA, CopA) in vitro.

The pcnB gene of Escherichia coli, which is required for ColE1 copy number maintenance, is dispensable

The pcnB gene product of Escherchia coli is required for copy number maintenance of plasmids related to ColE1 and also for that of the IncFII plasmid R1. Because PcnB is similar to the tRNA-binding protein tRNA nucleotidyltransferase, we have suggested that the protein would be required only for processes in which an RNA is a prominent regulatory component. This appears to be so; strains deleted for pcnB, although defective in ColE1 and R1 plasmid maintenance, maintain the iteron-regulated plasmids F and P1 normally. We also find that strains deleted for pcnB grow normally, demonstrating that PcnB has no essential cellular role under the conditions tested and suggesting that regulation by antisense RNAs similar to RNAI has no critical role in any essential host process. We confirm by immunological tests that PcnB is likely to be the commercially available enzyme poly(A) polymerase.

[Memory function of patients with cerebral arteriosclerosis evaluated by Rivermead behavioural memory test]

Using Rivermead behavioural memory test, we examined 142 patients with cerebral arteriosclerosis. The results showed that the rate of anomalies of screening score in patients with cerebral arteriosclerosis were significantly higher than that of the control group (P < 0.01). The patients and control scores were significantly different (P < 0.05) in all items except the picture and face recognition. Comparing the screening score with brain CT scan, we found a relationship between brain damage and behavioural memory declination. Also, many persons of control group got low scores with behavioural memory test, suggesting that the Rivermead behavioural memory test be sensitive to memory declination. With its simplicity and sensitivity the Rivermead behavioural memory test may have some practical value in China.

Highly sensitive object location in tissue models with linear in-phase and anti-phase multi-element optical arrays in one and two dimensions

Based upon previous observations of low-frequency photon diffusion waves within highly scattering tissue, this paper explores the "near-field" phenomena of such waves of approximately 10-cm wavelength with 200-MHz phase modulation equipment. Multiple-element source arrays consist of laser diode sources modulated at 180 degrees out of phase with respect to the other sources. The diffusing waves originating from the out-of-phase sources give, in the midplane, an amplitude null and a sharp phase transition. These may be observed in a highly scattering intralipid medium simulating the breast or brain (0.5% intralipid), 3-5 cm from the transmitting laser diodes. In the plane containing the array, there is a high sensitivity for a small volume of a hidden absorber (indocyanine green) deep within a highly scattering medium; 20 pmol in a volume of 70 microliters can be detected. Two-dimensional arrays consisting of four or more elements in two orthogonal planes give sensitivity on both axes similar to the one-dimensional array. Measurements show that in the presence of a light-absorbing object, the amplitude null and the interference plane becomes a curved surface which is deflected toward the heterogeneity. The degree of deflection is related to the volume and the absorption characteristics of the heterogeneity and provides detection of the heterogeneity, and thereby may provide localization information for the detection of small tumors within the human breast, or stroke volumes, aneurysms, and tumors in the human brain.

Aberrations of p53 gene in human hepatocellular carcinoma from China

Allele losses and mutations have been examined in 38 cases of primary hepatocellular carcinomas (HCC) from different geographic areas of China by Southern, single-strand conformational polymorphism (SSCP) and direct DNA sequencing analyses. Two of 12 samples from Qi-Dong and six of 18 HCCs from Shanghai showed loss of heterozygosity (LOH) at the loci on chromosome 17p13.3. All of the nine mutations in the p53 gene detected in HCC from Qi-Dong were clustered at the third base of codon 249, i.e. G:C to T:A, leading to an arginine to serine change. In contrast, 18 HCC samples from Shanghai contained three mutations at codons 249, 255 and 279. These results suggested a relationship between the spectrum of p53 aberration and environmental risk factors in these two geographic areas. Since no correlation between the state of HBV DNA and p53 aberration was observed, other factors such as dietary exposure to aflatoxin B1 (AFB1) might be responsible for the mutational hotspot at codon 249 in HCCs from Qi-Dong area.

Mechanisms underlying chemoreceptor inhibition induced by atrial natriuretic peptide in rabbit carotid body

1. Previous studies in our laboratory revealed the presence of atrial natriuretic peptide (ANP) in preneural chemosensory type I cells of the cat carotid body, and demonstrated that submicromolar concentrations of the peptide inhibited carotid sinus nerve (CSN) activity evoked by hypoxia. In the present study, we have evaluated the role of the cyclic nucleotide second messenger, cyclic GMP (cGMP), and the involvement of type I cells in rabbit chemosensory inhibition. 2. Submicromolar concentrations of the potent ANP analogue, APIII, greatly elevated both the content and release of cGMP from the carotid body. Denervation experiments confirmed earlier immunocytochemical studies which suggested that APIII-induced cGMP production occurs almost exclusively in type I cells; these experiments also indicate that both the sympathetic and sensory innervation to the carotid body exert a trophic influence on the metabolism of this second messenger. 3. Submicromolar concentrations of APIII inhibited the CSN activity evoked by hypoxia (79.8 +/- 3.2% (mean +/- S.E.M.) inhibition with 100 nM APIII) and nicotine (74.5 +/- 3.6% inhibition with 100 nM APIII), but did not affect basal CSN activity established in 100% O2-equilibrated superfusion solutions. 4. The biologically inactive analogue of ANP, C-ANP, failed to produce CSN inhibition; however, the inhibitory effects of APIII were mimicked by cell-permeant analogues of cGMP (dibutyryl-cGMP and 8-bromo-cGMP, 2 mM), which likewise did not alter basal CSN activity. Because we found that unmodified cGMP was an ineffective inhibitor of CSN activity, our data suggest that APIII inhibition is mediated intracellularly by cGMP produced within the type I cells. 5. APIII does not inhibit the CSN activity produced by 20 mM K+ (in zero Ca2+ media), which very probably results from direct depolarization of the sensory nerve terminals. 6. Catecholamine release from the carotid body evoked by hypoxia is likewise not altered by APIII (100 nM). 7. The data are consistent with the notion that APIII and analogues of cGMP alter the release of excitatory and/or inhibitory transmitters from chemosensory type I cells in the carotid body.

Effect of stem cell factor on in vitro erythropoiesis in patients with bone marrow failure syndromes

Stem cell factor (SCF) enhances normal hematopoiesis. We examined its effect in vitro on bone marrow and blood progenitors from patients with inherited bone marrow failure syndromes, including 17 patients each with Diamond-Blackfan anemia (DBA) and Fanconi's anemia (FA), 3 with dyskeratosis congenita (DC), and 1 each with amegakaryocytic thrombocytopenia (amega) and transient erythroblastopenia of childhood (TEC). Mononuclear cells were cultured with erythropoietin (Ep) alone or combined with SCF or other factors. SCF increased the growth of erythroid progenitors in cultures from 50% of normal controls, 90% of DBA, 70% of FA, 30% of DC, and the amega and TEC patients; normal numbers were reached in 25% of DBA studies. Improved in vitro erythropoiesis with SCF in all types of inherited marrow failure syndromes does not suggest a common defect involving kit or SCF, but implies that SCF may be helpful in the treatment of hematopoietic defects of varied etiologies.

A high performance liquid chromatographic method for the determination of albuterol enantiomers in human serum using solid phase extraction and chemical derivatization

A high performance liquid chromatographic method was developed for the simultaneous assay of R(-)- and S(+)-albuterol in human serum. The assay involves solid phase extraction as a sample clean-up step and derivatization of racemic albuterol to its diastereomeric thioureas with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl isothiocyanate. Chromatographic separation was accomplished under isocratic conditions using an octadecylsilane column and a mobile phase consisting of 29:71 acetonitrile:distilled water containing 0.1% triethylamine, pH 4.0 (adjusted with concentrated phosphoric acid) at a flow rate of 0.8 mL/min. The diastereomers were detected using a fluorescence detector set at 223 nm excitation and no emission filter. Racemic bamethane was used as internal standard. Drug to internal standard peak-height ratios were linear over a 2-20 ng/mL range for each enantiomer. The limit of detection of each analyte was 1.0 ng/mL (S/N = 3).

Caudate Nucleus and Pain Modulation

The caudate nucleus has an antinociceptive function related to the opioid peptidergic activity of the periaqueductal gray. Intracaudate opioid peptides and acetylcholine promote acupuncture analgesia, whereas dopamine antagonises it.

Primary-structural and evolutionary analyses of the growth-hormone gene from grass carp (Ctenopharyngodon idellus)

The growth-hormone (GH) gene of grass carp, one of the fastest-growing species of farmed fish, was isolated and the DNA sequenced. Only one GH gene is found in this species. This gene, which is 2.5 kb in length, has five exons and four introns, in common with all of the mammalian and the recently published common-carp GH genes. In the course of vertebrate evolution, the total lengths of the intron and the non-coding region of exon 5 of the GH gene have been shortened by 40-70%, whereas the encoding exons of the gene have been slightly increased. The more closely related species exhibit the closest sequence similarity in their GH genes. For example, the similarity of the exons is 84.1-93.2% between grass carp and common carp (within the same family of Syprinedae), 43.5-82.1% between grass carp and rainbow trout (in different orders of Teleostei) and 45.8-58.6% between grass carp and rat (in different grades of Vertebrata). In addition, similar DNA domains, such as thyroid-hormone-receptor-complex-binding site and cell-type-specific cis elements involved in regulation of expression of rat and human GH genes, have been localized in the corresponding regions of the grass-carp GH gene.

Two Saccharomyces cerevisiae kinesin-related gene products required for mitotic spindle assembly

Two Saccharomyces cerevisiae genes, CIN8 and KIP1 (a.k.a. CIN9), were identified by their requirement for normal chromosome segregation. Both genes encode polypeptides related to the heavy chain of the microtubule-based force-generating enzyme kinesin. Cin8p was found to be required for pole separation during mitotic spindle assembly at 37 degrees C, although overproduced Kip1p could substitute. At lower temperatures, the activity of at least one of these proteins was required for cell viability, indicating that they perform an essential but redundant function. Cin8p was observed to be a component of the mitotic spindle, colocalizing with the microtubules that lie between the poles. Taken together, these findings suggest that these proteins interact with spindle microtubules to produce an outwardly directed force acting upon the poles.

Pure rhabdomyosarcoma of the corpus uteri in a postpartum patient: report of a case and review of the literature

Pure rhabdomyosarcomas originate in the female genital tract. They are uncommon and most often occur in infancy or childhood as sarcoma botryoides (embryonal rhabdomyosarcoma) which involve the vagina and cervix. Such tumors rarely occur in adults. A pure rhabdomyosarcoma of the uterus that arose in a postpartum patient is described. The pertinent literature is discussed.