Disruption of primary mesenchyme cell patterning by misregulated ectodermal expression of SpMsx in sea urchin embryos

The patterning of the mesoderm of the sea urchin embryo is a classical paradigm of epithelial mesenchymal interactions in organogenesis, yet little is known of its molecular basis. Here we address the role of the homeobox gene, SpMsx, a member of the highly conserved Msx gene family, in this process. Msx genes have been shown to function in the dorsoventral patterning of the central nervous system in Drosophila and in a variety epithelial-mesenchymal interactions in vertebrates. We showed previously that the SpMsx gene is expressed during embryogenesis in a complex and dynamic pattern consistent with roles in the development of subpopulations of endoderm, mesoderm, and oral ectoderm. To perturb this pattern of expression and thus probe the function of SpMsx, we injected SpMsx mRNA into single-cell zygotes and monitored development morphologically and with a series of territory-specific molecular markers. RT-PCR analysis revealed that injected SpMsx transcripts persisted at least until the gastrula stage in amounts comparable to endogenous levels. Injected embryos exhibited deficiencies in the organization of primary and secondary mesenchyme cells within the blastocoelic cavity, as well as abnormalities in spicule number and shape. Defects in the endoderm were also common, including reduced or absent archenterons. Micromere transplantation experiments revealed that the defects in skeletogenic mesenchyme patterning were non-cell autonomous, consistent with findings that cell-cell interactions between ectoderm and the progenitors of the skeletogenic mesenchyme, the primary mesenchyme cells (PMCs), are important both for PMC guidance and spicule morphogenesis. Our data, taken together with observations in other organisms on the role of Msx genes in embryonic signaling processes, particularly involving the BMP pathway, suggest that SpMsx may be a part of the mechanism by which the ectoderm influences both the arrangement of primary mesenchyme cells within the blastocoel and the shapes of the skeletal rods.

Reversed-phase high-performance liquid chromatographic measurement of the P-aminobenzoic acid synthesized by Streptococcus sanguis

OBJECTIVE

This study investigated the biosynthesis of P-aminobenzoic acid by Streptococcus sanguis and the role of P-aminobenzoic acid in the interaction between Streptococcus sanguis and Streptococcus mutans.

METHODS

A reversed-phase high-performance liquid chromatographic technique was used to analyze the P-aminobenzoic acid synthesized by Streptococcus sanguis in an anaerobic atmosphere.

RESULTS

The results showed, that (1) the chromatographic method established in this study had good linear relation and the average recovery of P-aminobenzoic acid was 80%, and (2) Streptococcus sanguis did synthesize P-aminobenzoic acid, and the mean concentration of P-aminobenzoic acid was 1.23 micrograms/mL.

CONCLUSIONS

The results of this study will help further studies of the factors that may have effects on P-aminobenzoic acid synthesis by Streptococcus sanguis and on the role of P-aminobenzoic acid in the microbial homeostasis of dental plaque.

A rapid method for determination of in vitro susceptibility to antibiotics with a bulk acoustic wave bacterial growth biosensor

A novel bulk acoustic wave (BAW) bacterial growth biosensor was developed to study in vitro susceptibility by continuous monitoring of disturbances of bacterial growth at low antibiotic concentrations, followed by the accurate and rapid estimation of growth kinetic parameters and minimum inhibitory concentrations (MICs). The susceptibilities of bacteria, e.g. Escherichia coli, Staphylococcus aureus, Proteus vulgaris, Pr. morganii and Pr. mirabilis, to various antibiotics, e.g. penicillin, streptomycin, gentamicin and cefotaxime, were investigated, respectively, and the MICs were rapidly determined with a higher reproducibility than the conventional broth micro-dilution technique (BMDT). The effects of cell constant of conductivity electrode, pH and temperature on bacterial growth and biosensor signals were discussed in detail. The proposed method offers an effective alternative to the conventional methods.

Bulk acoustic wave bacterial growth sensor applied to analysis of antimicrobial properties of tea

A bulk acoustic wave (BAW) bacterial growth sensor has been proposed for study of inhibitory effects of tea by continuous monitoring of disturbances in Proteus growth in the aqueous extracts of various teas, e.g. green tea, Fuzhuan brick tea, Oolong tea, Kudin tea, and black tea. The kinetic parameters, e.g. asymptote (A), maximum specific growth rate (microm), lag time (lambda), and generation time (g), accurately estimated by using the growth response model, have been first used to characterize antimicrobial properties of tea. All of the parameters were changed via the inhibitory effects by tea. Green tea gives the weakest inhibitory action while others show stronger inhibitory actions. These inhibitory effects have also been examined by using the pour plate count technique. Both of the results show that, in addition to the antimicrobial properties of tea polyphenols and catechins, etc., the inhibitory effects may be attributed to the metabolites produced during the fermentation processing of these teas except green tea. The conventional disk diffusion test has been used to determine the minimum inhibitory concentration (MIC) against P. rettgeri. The MICs of green tea, Fuzhuan brick tea, Oolong tea, and black tea were found to be 1113, 818.0, 681.2, and 510.4 microg/mL, respectively. The BAW bacterial growth sensor has shown to have advantages over other techniques, including the disk diffusion test, photometry, and the impedance method.

Pelvic ultrasound measurements in normal girls: relation to puberty and sex hormone concentration

Pelvic ultrasonography was performed on 75 normal girls. Values were obtained for uterine length, fundal/cervical ratio (FCR), ovarian volume and sex hormones. The resultant data were grouped according to age and pubertal stage (Tanner). For uterine length, FCR and ovarian volume, the data were positively skewed, and the variance increased with age and pubertal stage (p < 0.001). The uterus underwent a regular increase in size and the corpus gradually became larger than the cervix. Uterine length, right ovary volume, FCR and hormones (serum estradiol, follicle-stimulating hormone and luteinizing hormone) showed a correlation with the Tanner score (p < 0.001). Although the correlations were significant, the best correlation was between pubertal stage and serum estradiol level.

[Local amyloidosis of stomach]

OBJECTIVE

To improve the diagnostic rate of local amyloidosis of stomach.

METHOD

One case of local amyloidosis of stomach was reported and the literatures were reviewed on the etiopathology, clinical features, diagnosis, treatment and prognosis.

RESULT

The patient was negative for family history and other chronic disease. Total gastrectomy was taken and was eventually found to have localized amyloidosis of stomach and regional lymph nodes. The amyloidosis was found to be of AA amyloidosis. Multiple biopsy specimens taken from esophagus, duodenum, rectum and bone marrow showed no amyloid deposition.

CONCLUSION

Amyloidosis should be considered in the differential diagnosis of gastric tumors, and also should be removed by operation if complications are to be prevented.

The Streptomyces coelicolor sporulation-specific sigma WhiG form of RNA polymerase transcribes a gene encoding a ProX-like protein that is dispensable for sporulation

In the non-motile mycelial organism Streptomyces coelicolor A3(2), the sporulation gene whiG encodes a protein that closely resembles RNA polymerase sigma factors such as sigma D of Bacillus subtilis, which mainly control motility and chemotaxis genes. Here, we show that the whiG gene product, purified from an Escherichia coli strain carrying an expression construct, could activate E. coli core RNA polymerase in vitro to transcribe a sigma D-dependent motility-related promoter from B. subtilis. Such RNA polymerase holoenzyme preparations could also transcribe from an S. coelicolor promoter, PTH4, previously shown to require an intact whiG gene for in-vivo transcription. The in-vivo dependence on whiG was therefore shown to be direct. Unusually, the initiation of PTH4 transcription in vitro depended on the provision of appropriate dinucleotides. The whiG-dependent PTH4 transcription unit consisted of a single gene, orfTH4. Sequence comparisons suggested that the gene product was a member of a small group of proteins that include the B. subtilis and E. coli ProX proteins. Though none of these proteins shared more than about 30% of extended primary sequence identity, they had similar size and hydropathy profiles, and could be aligned end to end to reveal a mosaic of similarities. The ProX proteins of B. subtilis and E. coli are implicated in glycine betaine transport in response to hyperosmotic stress. However, disruption of orfTH4 did not cause any obvious phenotypic changes in growth or development on media of varying osmotic strengths.

[Augmented effect of Composite Radix Salviae Miltiorrhizae Injection on radiosensitivity of leukemia cells]

OBJECTIVE

To explore the effect of Composite Radix Salviae Miltiorrhizae Injection (CSMI) on radiosensitivity of leukemia cells.

METHODS

Semisolid agar culture and flow cytometry assay were performed for studying the change in radiosensitivity of HL60 cell line and fresh human leukemia cells after exposing to CSMI.

RESULTS

The D0(the inverse of the slope of the survival curve) and SF2(survival fraction at 2 Gy) of HL60 cell line were decreased from 1.53, 0.34 to 0.93, 0.12, respectively and apoptosis rates after radiation were raised significantly by CSMI. Furthermore, the concentration of CSMI and the time of mixed culture with CSMI before irradiation had positive relation to the effects mentioned above. Compared with control group, CSMI could increase the radiation-induced apoptosis of fresh leukemia cells (5.89 +/- 2.91% vs 12.05 +/- 3.06%).

CONCLUSION

CSMI could obviously enhance the radiosensitivity of leukemia cells.

Tuberculosis of the nasopharynx following radiotherapy

We report the case history of a patient who was treated with radiotherapy for nasopharyngeal carcinoma. During follow-up, she showed signs, symptoms and radiological evidence of disease recurrence and progression. However, repeated biopsies of the posterior nasal space (PNS) failed to demonstrate malignancy. A diagnosis of nasopharyngeal tuberculosis was finally made when tissue from a PNS biopsy stained positive for acid-fast bacillus. The patient responded to antituberculous chemotherapy.

Atmospheric mercury deposition on Fanjing Mountain Nature Reserve, Guizhou, China

Fanjing Mountain Nature Reserve (FMNR) is surrounded with several Hg emission sources within distances of 100-200 km. At the two sites studied, Tongren and Danzai, Hg emission and deposition fluxes, Hg concentration in the air, soil and other samples are all several hundred times higher than at other relatively clean areas. Hg accumulation in soil and moss at FMNR varies with the sampling heights. Total Hg deposition to this area has been estimated to be 115 micrograms m-2 y-1 using moss bag technique. Dry deposition was determined to be about 5.2 micrograms m-2 month-1 during March to June, corresponding to more than 50% of the total deposition.

[Spinal segment distribution of neural innervation related to houhai acupoint and compared with zusanli and dazhui acupoints in domestic chicken]

OBJECTIVE

The aim of this study was to demonstrate the spinal segmental innervation of Houhai, Dazhui and Zusanli acupoints in domestic chicken.

METHODS

The horseradish peroxidase conjugated cholera toxin B subunit (CB-HRP) was injected into the regions of the three acupoints namely, Houhai Dazhui and Zusanli respectively in separate groups of chicken. The frozen sections of spinal cord and dorsal ganglia were prepare for labelling using TMB as a chromogen.

RESULTS

(1) In Houhai group the anterograde transganlionic labelling terminals were densely distributed in the dorsal horn and dorsal commissure nucleus. The moto-neurons in ventral horn labelled retrogradely appeared fine arborization of dendrites. There were labelled cell bodies in the dorsal region of the ventral horn (lamina VII) or dorsal commissure nucleus. (2) In Dazhui group, the bundles of labelled fibers presented from laminea I and II to IX in the caudal cervical enlargements and two upper thoracic segments. The labelled motoneurons were shown in medial and lateral groups. The most numourous of labelled ganglionic cells appeared in this group. (3) The labelling sensory ganglionic neurons and their terminals in spinal cord related Zusanli acupoint were overlaped with those related Houhai acupoint. The largest numbers of the labelled ventral motoneurons occured in the Zusanli group.

CONCLUSIONS

The results demontrated the patterns of segmental innervation corresponding respectively to Houhai, Dazhui, and Zusanli acupoints. The anterograde afferent labelling terminals and interrelationship of the dendritic arborization of retrograde labelling motoneurons (somatic or visceral) provided neuroanatomical evidences for the innervation of the acupoints.

Health status of senior civil servants in Kuala Lumpur

733 senior civil servants comprising 520 males and 213 females with a mean age of 44 years (range 25-56 years) were screened for their health status. The sample population comprised of 67.9% Malays, 22.5% Chinese, 9.1% Indians and 0.4% other ethnic origins. The subjects' medical histories were recorded and a full medical examination including anthropometric measurements (weight, height, waist and hip circumference), blood biochemistry and urine analysis, chest X-ray and electrocardiograms were done. The results obtained showed that 36.0% of the study population were overweight with 6.5% being obese. Of this 32.0% had central obesity. 15.2% of the subjects had systolic hypertension (systolic BP > or = 140 mmHg) whilst 27.6% had diastolic hypertension (diastolic BP > or = 90 mmHg). Hyperlipidaemia was common, with 75.2% subjects having raised cholesterol, 19.9% raised triglycerides, 50.2% raised LDL-C, 74.6% raised TC:HDL-C and 26.6% raised LDL:HDL-C. An elevated blood glucose was found in 8.4% subjects, whilst urine sugar was detected in only 2.6%, and a raised uric acid was found in 2.8% subjects. The prevalence of hypertension, raised blood glucose and hyperlipidaemia increased with age with more males affected than females. Although hypercholesterolaemia appeared more frequently amongst the Malays, the Indians, by comparison had the highest prevalence for a raised LDL:HDL-C ratio, a reflection of the increase in LDL-C and a concomitant decrease in HDL-C. The latter findings indicate that the Indians are at greater risk for the development of coronary heart disease than the Chinese and Malays. In addition, the mean levels of serum cholesterol found in this study seemed to have exceeded the levels found in populations in the industrialised countries such as the USA. There is thus an urgent need for more public health campaigns aimed at the reduction and control of such coronary risk factors.

Characterization of dye-induced mobility shifts affecting DNA sequencing in poly(ethylene oxide) sieving matrix

The influence of three classes of fluorescence labels including dipyrrometheneboron difluoride (BODIPY), energy transfer (ET) and conventional fluorescein and rhodamine (ABI), on DNA sequencing has been examined with laser-induced fluorescence detection and poly(ethylene oxide)-filled capillary electrophoresis. DNA sequencing fragments were generated by dye-labeled primer cycle-sequencing reactions in a hot-air thermal cycler. A parameter, relative-induced shift, was introduced to quantify the uniformity of electrophoretic mobilities of these fragments. BODIPY was found to have the smallest, but nonzero, effect for dye-induced nonuniformity. Although ET dyes provided the highest sensitivity due to their unique spectroscopic properties, they were found to lack photostability compared to BODIPY and ABI dyes. Characterization also brings out some important tips for selecting the suitable dye set for the two-channel ratio-based DNA base-calling method.

[Cloning and endonuclease digestion of lon gene from Streptomyces ansochromogenes]

Streptomyces ansochromogenes is a nikkomycin producer which has typical life cycle of Streptomyces differentiation on glucose asparagine medium. The lon gene product is an ATP-dependent serine proteinase. The lon gene might have some connection with physiological differentiation and also with the morphological differentiation in S. coelicolor. The lon-like gene of S. ansochromogenes was identified by hybridization and the lon-like gene in 4.6 kb PstI fragment was cloned. The physical map of this fragment and the localization of the target gene were preliminarily studied.

[Histochemical localization of nitric oxide synthase in the human placenta]

OBJECTIVES

To study localization, distribution and activity of nitric oxide synthase (NOS) in the human placenta and to speculate the action of nitric oxide (NO) during pregnancy.

METHODS

NADPH-diaphorasc histochemical method was used to indicate the distribution, localization and activity of NOS in the placentae of normal term pregnancy (n = 21). Severe pregnancy induced hypertension (PIH) (n = 15), intrauterine growth retardation (IUGR) (n = 2) and villi of early pregnancy (n = 16).

RESULTS

The NOS reactive product called blue formazan was found in most of syncytiotrophoblast (STr) and located in top of cells in severe PIH and IUGR placentae. In normal term placentae the blue formazan was found in STr and located in base of cells. The number of blue formazan was more than that of PIH and IUGR placentae. Endothelial cells of most capillaries of the terminal villi in severe PIH and IUGR placentae were found to be deposited with blue formazan, but in normal term pregnancy, blue formazan was found only on rare occasion.

CONCLUSION

Distribution and localization of NOS in placentae of normal term pregnancy, severe PIH and IUGR cases and early villi are specific. The NOS activity of STr in severe PIH placentae and IUGR placentae are lower than that of normal term placentae. The distribution and localization of NOS within the STr in severe PIH placentae and IUGR placentae are different from those in normal term placentae. The low activity of NOS secreted by placenta may be relative to the pathogenesis of PIH and IUGR.

[Cloning and restriction analysis of saw1--a key gene for differentiation of Streptomyces ansochromogenes]

saw1--a essential gene for sporulation of Streptomyces ansochromogenes was cloned, 7 kb of DNA fragment in Streptomyces plasmid pIJ702 could recover the sporulation of saw1-deficient strain W51 which could not form spore with white phenotype of aerial hyphae. The recombinant plasmid was deleted by some restriction enzymes, the result showed that 2.5 kb DNA fragment in pIJ702 still has function to recover sporulation of W51. The sequencing and expression of saw1 gene is carrying out at present.

[Spinal segment distribution of neural innervation related houhai acupoint--studied by CB-HRP tracing method focused on observation of the dendrites of spinal motor neurons]

The spinal segment distribution of neural innervation related Houhai acupoint in rats has been investigted by using horseradish peroxidase conjugated cholera toxin B subunit (CB-HRP) tracing technique. Spinal motoneurons (Mn) in L6-S1 were labeled retrogradely by CB-HRP, and their features have been characterized: 1) their marginal plexus of the dendrites radially projected to the lateral and/or anterior funiculus and their distal portions forming subpial dendritic plexus; 2) the medial dendrites ran along the ventral margin of the gray commissure and their distal portions surrounded the central canal' forming a subependymal dendritic plexus. Both of them are Golgi-phobic. Some distal branches of dendrites penetrated to the contralateral gray matter. The dendritic arbors of the labeled motoneurons in the group of electro-acupuncture or group of acupoint-inoculation with sheep red blood cells contracted in comparison with that in the normal control group. The primary sensory transganglionic labeled fibers and preterminal fibers revealed by CB-HRP in the dorsal horn and dorsal commissural nucleus of the spinal cord (L5-S2) converged and overlaped with the dendrites of retrogradely labeled motoneurons. The results indicated there is a reflect circuit of afferent-integration-efferent neuro-network in the spinal cord related Houhai acupoint. The Mns retrogradely labeled by CB-HRP in the L6-S1 segments might be involved in Houhai acupuncture.

[Micrometastasis of colorectal carcinoma in bone marrow with immunohistochemical staining]

From April 1994 to April 1996, immunohistochemical technique was used to detect micrometastasis of patients with colorectal carcinoma with monoclonal antibody to epithelial membrane antigen (anti EMA). Positive cells were found in their bone marrow in 23 of 57 cases, including 14 in 34 patients with colonic carcinoma (positive rate 41%) and 9 in 23 patients with rectal carcinoma (positive rate 39.1%). The positive rate was 40.4%. Statistical analysis showed that the modified Dukes stage of the cancer, the pathological type of carcinoma and the age of the patients were correlated with the positive rate, but the primary locations of the cancer were not. This method can be used to identify the extent of the cancer and direct clinical comprehensive treatment for colorectal carcinoma.

In vivo transcription of two promoters, P(TH4) and P (TH270) involved in regulation ofStreptomyces differentiation

The promoters, P(TH4) and P(TH270) involved in the regulation ofStreptomyces coelicolor differentiation were subcloned intoStreptomyces promoter, i.e. probe plasmid pIJ4083, and the recombinant plasmids, pIJ4470 and pIJ4471, were constructed. Two promoters could drive the expression of reporter gene encoding catechol dioxygenase when pIJ4470 and pIJ4471 were introduced into some white mutants (C85, C70, C71, C17 and C119). The total RNA was isolated from these strains containing recombinant plasmid. Probes were prepared by labelling 5'-ends of P(TH4) and P(TH270) DNA fragments using radioisotope. DNA -RNA hybridization was carried out with the probes and RNAs isolated from different strains. The S1 mapping result showed that all RNAs from strains of C85/pIJ4470, C85/4471, C70/pIJ4470, C70/pIJ4471 and C17/pIJ4470 as well as C17/pIJ4471 gave rise to strong positive hybridization signal, whereas RNAs from C71/pIJ4470 and C71/pIJ4471 did not give any positive signal. RNAs from C119/pIJ4470 and C119/pIJ4471 gave weak hybridization signal. The result indicated that the transcription of both P(TH4) and P(TH270) promoters might depend onwhiG, an essential gene inStreptomyces differentiation, and partially depend on whiH, but they did not depend on other differentiation genes (whiA, whiB andurhiI).

Serum lipids and their relationship with other coronary risk factors in healthy subjects in a city clinic

Over a thousand subjects who visited a city private medical clinic for health screening and advice were examined for their lipid profile and other cardiovascular risk factors. The mean TC, TG, LDL-C and HDL-C were 5.43, 1.45, 3.61 and 1.15 mmol/l. Their derived ratios viz, TC:HDL-C and LDL:HDL-C were 5.11 and 3.43 respectively. The prevalence of hyperlipidaemia was moderately high. Of the subjects studied 58.5% had elevated serum cholesterol, 14.8% had raised triglycerides, 64.9% had raised LDL-C and 20.8% had low HDL-C. Male subjects generally showed higher mean values and abnormality frequency in TC, TG, LDL-C, TC:HDL-C and LDL:HDL-C as compared to female subjects. Although significant ethnic differences were not detected for certain lipid parameters (e.g. TC, TG and HDL-C), the Indians appeared to have higher mean lipid values (except HDL-C), and higher percentage abnormality for all the lipid parameters as compared to the Chinese and the Malays. In correlation studies, the following lipid parameters:- TC versus TG, LDL-C, TC:HDL-C; TG versus TC:HDL-C and LDL:HDL-C; LDL-C versus TC:HDL-C and LDL:HDL-C; were positively correlated. On the other hand, TC versus HDL-C, TG versus HDL-C, LDL-C and HDL-C, and HDL-C versus TC:HDL-C and LDL:HDL-C were negatively correlated. The coronary risk factors which generally showed positive correlations with lipid parameters were BMI and blood pressure. Positive correlations were also recorded between fasting blood glucose and TG; uric acid with TG, TC:HDL-C and LDL:HDL-C. In contrast, risk factors of negative correlations were observed between HDL-C and the coronary risk factors of BMI, diastolic blood pressure and uric acid. Smoking showed raised per cent lipid abnormality for TG, HDL-C, TC:HDL-C and LDL:HDL-C. Alcohol consumption also increased the mean level and abnormality frequency for TG. The implication of this investigation is discussed.

Amyloid precursor protein processing and A beta42 deposition in a transgenic mouse model of Alzheimer disease

The PDAPP transgenic mouse, which overexpresses human amyloid precursor protein (APP717V-->F), has been shown to develop much of the pathology associated with Alzheimer disease. In this report, levels of APP and its amyloidogenic metabolites were measured in brain regions of transgenic mice between 4 and 18 months of age. While absolute levels of APP expression likely contribute to the rate of amyloid beta-peptide (Abeta) deposition, regionally specific factors also seem important, as homozygotic mice express APP levels in pathologically unaffected regions in excess of that measured in certain amyloid plaque-prone regions of heterozygotic mice. Regional levels of APP and APP-beta were nearly constant at all ages, while A beta levels dramatically and predictably increased in brain regions undergoing histochemically confirmed amyloidosis, most notably in the cortex and hippocampus. In hippocampus, A beta concentrations increase 17-fold between the ages of 4 and 8 months, and by 18 months of age are over 500-fold that at 4 months, reaching an average level in excess of 20 nmol of A beta per g of tissue. A beta1-42 constitutes the vast majority of the depositing A beta species. The similarities observed between the PDAPP mouse and human Alzheimer disease with regard to A beta42 deposition occurring in a temporally and regionally specific fashion further validate the use of the model in understanding processes related to the disease.