Coherent stimulated Raman emission from a microcavity-excited optical resonator

We report the observation of coherent emission from a planar Fabry-Perot resonator driven by a single, coherently emitting microcavity. The microcavity, either a liquid microdroplet or microcylinder, emits coherent stimulated Raman scattering when irradiated by an intense pump laser; the Raman light, in turn, couples to modes of the resonator. The spatiotemporal characteristics of resonator emission are strongly influenced by the microcavity source within; notably, a significant excess time delay in the emission of stimulated Raman scattering (i.e., compared with that of the microcavity in free space) accompanies the appearance of a sharp resonator spatial interference pattern. This and other noteworthy features are described, and a qualitative discussion of their significance is given.

Efficacy of autologous peritoneum as a biological membrane in cardiac surgery

The risks for reoperative cardiac surgery are related to the presence of intrapericardial adhesions and the possibility of catastrophic injury at repeat sternotomy. In an attempt to develop an improved pericardial substitute and vascular patch, the feasibility of using autologous peritoneum was evaluated. Twelve mongrel dogs were studied. A peritoneal-rectus fascia patch, including the overlying posterior rectus sheath was harvested, via a lateral abdominal incision, and stored in normal saline. In the first group of six animals, a pulmonary artery (PA) window was created and then closed with the peritoneal-rectus fascia patch. In the second group a secundum atrial septal defect was created and then closed with the peritoneal patch on cardiopulmonary bypass (CPB). In each animal, the peritoneal-rectus fascia patch was used to permit pericardial closure. Autopsies performed at 90 days postoperatively revealed only slight intrapericardial adhesion formation and a mild epicardial reaction. Histological examination of the peritoneal-rectus fascia patches revealed intact morphology with active fibroblasts and smooth muscle cells. Proline 14C absorption and autoradiography detected viable cells in the implanted patches. These findings suggest that a peritoneal-rectus fascia allograft could be useful as a biological membrane, and as a satisfactory pericardial substitute in the development of strategies to reduce the risk for reoperative cardiac surgery.

[Line width addition method and its application to biologic materials emission spectrum analysis]

Using alternating current are grating spectrograph, and self-made recording microphotometer for line contour and accurate measurement of line width, we measured the concentration of Cu and Ca in serum-like synthetic standard solution with line width addition method. The experimental results had better linearity, reproducibility and higher precision compared with those by density method, suggesting that line width method is better than density method in the analysis of biologic material concentration.

N-acetylglucosaminyltransferase III and V messenger RNA levels in LEC rats during hepatocarcinogenesis

The LEC (Long-Evans with a cinnamon-like color) rat is a mutant of the Long-Evans strain which develops hereditary hepatitis and hepatoma with age. Activities and mRNA levels of N-acetylglucosaminyltransferase III and V (GnT-III and GnT-V, respectively) were determined during hepatocarcinogenesis in this rat using a LEA (Long-Evans with an agouti color) rat as a control. GnT-III activity in LEC rat liver increased after 30 weeks of age, at the stage of chronic hepatitis, to about 2.5-11.5 times the level in LEC rats aged 1-9 weeks. GnT-V activity in the LEC rat liver increased after 20 weeks of age, at the stage of acute hepatitis, to about 1.5-2.5 times the level in LEC rats of 1-9 weeks of age and then remained elevated. Both enzymes showed more dramatic increases in males than in females. The mRNA levels of the enzymes increased in proportion with the enzyme activities. Furthermore, GnT-III and GnT-V mRNAs were highly expressed in both cancer lesion and adjacent tissues. In one case of hepatoma with lymph node metastasis, GnT-III and GnT-V mRNA expression was much higher in the metastatic lesion than in the original cancer. GnT-III and GnT-V levels in the original cancer lesions were similar to those in the cancer lesions of the other LEC rats. These results indicated that expression of GnT-III and GnT-V was induced by chronic liver damage and hepatocarcinogenic changes in the LEC rats.

Analysis of Leaf Sectors in the NCS6 Mitochondrial Mutant of Maize

The nonchromosomal stripe (NCS6) mutation of maize is a partial deletion of the mitochondrial cytochrome oxidase subunit 2 (Cox2) gene. The Cox2 deletion and a narrow yellow striping phenotype are inherited together in a maternal fashion. The striped plants are heteroplasmic for mutant and normal Cox2 genes. Only the mutant Cox2 gene is detected within the yellow stripes, whereas both normal and mutant forms of the gene are present in the green sectors of the NCS6 plants. In the green leaves of nonstriped relatives, only the normal Cox2 gene is found. Both the structure and functioning of the chloroplasts in the yellow leaf sectors of NCS6 plants are altered. The pleiotropic effects of the NCS6 mutation suggest that mitochondrial function is required for the development of photosynthetically competent chloroplasts.

Acquired amegakaryocytic thrombocytopenic purpura with a Philadelphia chromosome

A 30-year-old Chinese man with acquired amegakaryocytic thrombocytopenic purpura (AATP) and a Ph chromosome is reported. At presentation, he had severe thrombocytopenia resulting in epistaxis, gingival bleeding, and ecchymoses, while other hematologic values were within the normal range. Bone marrow aspiration showed no megakaryocytes, with a normal appearance of erythroblastic and granulopoietic series. He failed to respond to prednisone treatment, and underwent a progress from isolated thrombocytopenia to full pancytopenia. At last he died of spontaneous intracranial hemorrhage. An in vitro culture for granulocyte-macrophage precursors showed very few colonies. Karyotypic analysis revealed a standard Ph chromosome translocation, t(9;22)(q34;q11), in the majority of bone marrow cells. Southern blot analysis using a 3' bcr-HE probe didn't detect a rearrangement within the bcr DNA sequence. This patient, in fact, was a myelodysplastic disorder, initially presenting as AATP. The diagnosis of chronic myelogenous leukemia was excluded on the basis of clinical and hematologic findings. The heterogeneity of Ph chromosome in myelodysplastic syndrome is discussed.

Determinants of contraceptive method choice after first delivery, before first abortion, and after first abortion in east China

A 10% sample of the data from East China from the two-per-thousand fertility and contraception survey of the Chinese State Family Planning Committee was analysed to study determinants of contraceptive choice in three situations: after first surviving delivery; before first abortion after first surviving delivery; and after first abortion. A total of 2880 women were included. For first method choice after first delivery, the most popular method is the IUD, although there are urban/rural differences. Better educated women in urban areas prefer the condom and IUD to the pill, whereas better educated women in rural areas prefer the pill. Younger women prefer the IUD and the pill. For last method choice before first abortion, women who had no sons had apparently high failure rates on the pill.

Purification and characterization of UDP-N-acetylglucosamine: alpha-6-D-mannoside beta 1-6N-acetylglucosaminyltransferase (N-acetylglucosaminyltransferase V) from a human lung cancer cell line

A beta 1-6N-acetylglucosaminyltransferase (GnT-V) [EC 2.4.1.155] which catalyzes the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to alpha-D-6-mannoside has been purified up to 20,000-fold from the cultured supernatant of the QG small lung cancer cell line with a 37% yield. The isolation procedure included chromatography on phenyl-Sepharose, hydroxylapatite, UDP-hexanolamine Sepharose, and a biantennary sugar substrate (GnGn-bi-Asn) coupled to activated CH-Sepharose 4B. Sodium dodecyl sulfate gel electrophoresis under non-reducing conditions showed a single band of 73 kDa. Under reducing conditions, however, an additional component of 60 kDa was seen. Peptide mapping analysis indicated that both of these proteins were essentially identical, indicating that the 60-kDa component is probably a proteolytically cleaved form of the 73-kDa protein. Studies on the activity of the enzyme toward a variety of pyridylaminated sugars showed that the enzyme is most active toward triantennary (GnGnGn-tri-PA) and biantennary (GnGn-bi-PA) sugars. The Km values for GnGn-bi-PA and UDP-GlcNAc were 133 microM and 3.5 mM, respectively. These studies represent the first report of the enzymatic properties of a highly purified human GnT-V.

Evidence that the nodulation regulatory gene nodD3 of Rhizobium meliloti is transcribed from two separate promoters

The Bgl II fragment carried in plasmid pMH903, which covers the nodD3 region of Rhizobium meliloti, has been sequenced. By using both S1 nuclease mapping and primer extension, two transcription start sites were demonstrated in the sequence. After the first transcription start site, there were two open reading frames (ORF) followed by the nodD3 coding sequence which was also preceded by the second promoter. The nodD3 gene under the first promoter mediated high, constitutive expression of nodC-lacZ fusion, and the gene under the second promoter required the product of nodD1 and alfalfa (Medicago sativa) seed exudate for the activation of fusion. Nodulation experiments showed that the nodD3 gene under either promoter was functional in eliciting nodules on alfalfa. The deletion of part of the two ORFs after the first promoter or deletion of the second promoter did not block the constitutive expression of nodC-lacZ fusion, whereas the deletion of the first promoter region or a polar insertion mutation between the two promoters did cause nodD3 to activate nodC only in the presence of the inducer. It indicates that nodD3 can be transcribed from the first promoter as well as from a separate second promoter.

Identification, localization and developmental studies of rat prepro thyrotropin-releasing hormone mRNA in the testis

Thyrotropin-releasing hormone (TRH) plays the central regulatory role in the hypothalamic-pituitary-thyroid axis, but is also present in many extra-hypothalamic loci. The adult rat testis has been identified previously as a source of hypothalamic neuropeptides including TRH. To investigate whether the TRH gene is transcribed in testis, the identification and localization of prepro(pp) TRH mRNA and TRH were studied. Northern blot analyses of ppTRH mRNA in the adult rat testis showed a 2.0 kb band, hybridized with a ppTRH cRNA probe. This band was 0.4 kb greater than the 1.6 kb hypothalamic band. The concentration of ppTRH mRNA in the adult testis was approximately 13% of that found in the hypothalamus. Developmental studies of testicular ppTRH mRNA revealed that no ppTRH mRNA could be detected at the earliest stage (day 8). However, hybridization signals were detected on day 20 and increased progressively on days 35, 45 and 70 by 5.8, 6.4, and 9.8-fold, respectively. In addition, ppTRH mRNA was determined in Leydig cells by Northern analyses of elutriated testicular cell fractions. TRH was also measured in the rat testes at different developmental stages by RIA. TRH concentrations paralleled ppTRH mRNA during development. TRH was localized to Leydig cells by immunohistochemistry. These results indicate that ppTRH mRNA and TRH are present in the rat testis, especially in the Leydig cells. The changes of ppTRH gene expression and the concentration of TRH in the rat testis are developmentally dependent. TRH may function as a new paracrine or autocrine regulator of testicular function.

Effects of submicrometer-sized particles on microdroplet lasing

We report the threshold emission characteristics of lasing from microdroplets that consist of Rhodamine 6G dye in an ethanol solution that contains undoped polystyrene latex spheres. The addition of latex particles to the droplets suppresses lasing. Our findings indicate that, for a fixed Rhodamine 6G concentration and fixed pump intensity, lasing ceases when a certain total-threshold latex particle surface area is reached in the droplet, independent of latex particle size. A possible explanation for these findings is the Förster-assisted annihilation of Rhodamine 6G dye lasing levels, facilitated by the adsorption of dye molecules on the surfaces of latex particles.

Application of GPIIIa gene Taq I polymorphism to determination of carrier status in Glanzmann's thrombasthenia families of Chinese origin

Glanzmann's thrombasthenia is a bleeding disorder caused by qualitative and/or quantitative defects of platelet membrane glycoprotein (GP) IIb/IIIa complex. The disease is inherited in an autosomal recessive manner. In this paper, cDNA probes were used to study restriction fragment length polymorphisms (RFLPs) in GPIIIa gene. A Taq I polymorphism was identified and this RFLP was composed of variant bands of 6.5 Kb/4.0 and 2.5 Kb with a frequency of 0.46/0.54 in Chinese population. The Taq I polymorphism was further localized by polymerase chain reaction (PCR) method to exon VIII of the GPIIIa gene. In two Glanzmann's thrombasthenia families, the Taq I RFLP studied by both Southern blotting and PCR methods identified the defective GPIIIa gene inherited by patients, and determined the genotype of asymptomatic subjects. Analysis of this Taq I polymorphism by PCR method should be potentially useful in future for the carrier detection and prenatal diagnosis in Glanzmann's thrombasthenia families.

Total metabolic flow of glycosphingolipid biosynthesis is regulated by UDP-GlcNAc:lactosylceramide beta 1-->3N-acetylglucosaminyltransferase and CMP-NeuAc:lactosylceramide alpha 2-->3 sialyltransferase in human hematopoietic cell line HL-60 during differentiation

We have previously reported that ganglioside GM3 was remarkably increased during monocytoid differentiation of human myelogenous leukemia cell line HL-60 cells and that neolacto series gangliosides (NeuAc-nLc) were enriched during granulocytoid differentiation. In addition, HL-60 was differentiated into monocytic lineage by exogenous GM3 and into granulocytoid by NeuAc-nLc. In the present report, the enzymatic bases of glycosphingolipid biosynthesis in HL-60 during differentiation induced by 12-O-tetradecanoylphorbol-13-acetate and all-trans-retinoic acid were investigated. The following results were of particular interest. (i) Lactosylceramide alpha 2-->3 sialyltransferase (GM3 synthase) was remarkably up-regulated during monocyte differentiation, while the GM3 synthase level did not change in granulocytic differentiation. (ii) By contrast, lactosylceramide beta 1-->3N-acetylglucosaminyltransferase (Lc3Cer synthase) was down-regulated during monocytic differentiation, while the activity of Lc3Cer synthase was found to increase in granulocytic differentiation. (iii) The activities of four downstream glycosyltransferases (for synthesis of NeuAc-nLc) were found to increase or to remain unchanged during monocytic and granulocytic differentiation. These results strongly suggested the following. The dramatic GM3 increase and the decrease of NeuAc-nLc during monocytic differentiation are the consequences of the up-regulation of GM3 synthase and the down-regulation of Lc3Cer synthase, although the downstream enzymes are ready to catalyze their enzyme reactions. The notable increase of NeuAc-nLc and the relative decrease of GM3 during granulocytic differentiation are the results of the unchanged level of GM3 synthase and the up-regulation of Lc3Cer synthase together with the activation of the downstream glycosyltransferases. These results suggest that these two key upstream glycosyltransferases, GM3 synthase and Lc3Cer synthase, play critical roles in regulating the glycosphingolipid biosynthesis in HL-60 cells during differentiation. This switching mechanism of these two glycosyltransferases, together with our previous findings, might be one of the most important parts of the determining system of differentiation direction in human myeloid cells into monocytic or granulocytic lineages.

Physical manipulation of subcutaneously implanted cardiac muscle in rat increased plasma atrial natriuretic peptide concentration

To examine the effects of physical stretch on cardiac muscle endocrine activity, the authors transplanted whole neonatal hearts subcutaneously into the back and the ears of the correspondent mother (n = 9). Seven days later, physical manipulation was applied on the implanted heart by stretching the skin and the subcutaneous tissue encasing the implanted cardiac muscle, for a period of five to ten minutes. Such manipulation was repeated approximately every seven days postoperatively for a total of two to four times for each rat. The plasma atrial natriuretic peptide (ANP) levels were measured by radioimmunoassay prior to and immediately following manipulation. Postmanipulation plasma ANP levels were found to increase from the premanipulation levels. At two weeks postimplant, the average increase was 290% with the highest single-specimen increase being nearly twelvefold. The increases observed at two and three weeks following implantation had Signed Rank Test p values of 0.015 and 0.042 respectively. The viability of the implanted hearts was confirmed by cell culture. Light microscopic immunocytochemistry detected ANP immunoreactivity in the implanted cardiocytes. The elevated plasma ANP concentration induced by the manipulation appeared to be correlated with the functional status of the implanted cardiocytes.

IN CONCLUSION

(1) Subcutaneously transplanted neonatal myocardiocytes survived for at least three to four weeks while retaining the ability to produce ANP. (2) Physical manipulation of implanted heart induced ANP release. Therefore, cardiac ANP production and release is indeed stimulated by physical stretching.

Deficiency of beta 1-6 N-acetylglucosaminyltransferase involved in the biosynthesis of blood group I antigen in the liver of LEC rats

The activities of the beta 1-6 and beta 1-3 N-acetylglucosaminyltransferase, which synthesize blood group I and i antigens, respectively, were measured in various tissues of hepatitis- and hepatoma-predisposed rats (LEC rats). In LEC rats the beta 1-6 N-acetylglucosaminyltransferase activity was barely detectable in the liver, while substantial enzyme activity was found in other tissues. In the control LEA rats the enzyme was expressed in most tissues, including the liver. Immunochemical studies using a monoclonal antibody which recognizes I antigen indicated that the expression of I antigen was less prominent in hepatocytes of LEC rats than in hepatocytes of LEA rats. The level of beta 1-3 N-acetylglucosaminyltransferase activity was constant in most of the tissues during the development. These results indicate that the biosynthesis of I antigen does not occur in the livers of the LEC rats.