Plastid development in disc cells of glandular trichomes of Cannabis (Cannabaceae)

Plastids in lipophilic glandular trichomes of chemically fixed (CF) and high pressure cryofixed-cryosubstituted (HPC-CS) bracteal tissues of Cannabis were examined by transmission electron microscopy. In CF preparations, plastids in disc cells prior to secretory cavity formation possessed several lobed and dilated thylakoid-like features. In glands with secretory cavities, thylakoid-like features aggregated to form reticulate bodies that distended regions of the elongated plastids. Electron-gray inclusions evident on the plastid surface appeared continuous with the reticulate body. Inclusions of similar electron density also appeared in the cell cytoplasm, along the plasma membrane, between the plasma membrane and cell wall facing the cavity, and in the secretory cavity in both CF and HPC-CS preparations. The bilayer structure of membranes of the plastid envelope was evident in HPC-CS but not in CF preparations. In HPC-CS preparations, secretions were evident on the plastid surface and were continuous with those in the plastid through pores in the envelope. This study supports an interpretation that these specialized plastids, lipoplasts, synthesize secretions that are transported through the plasma membrane and cell wall to subsequently accumulate in the secretory cavity.

Three-vessel view of the fetal upper mediastinum: an easy means of detecting abnormalities of the ventricular outflow tracts and great arteries during obstetric screening

The three-vessel view is a transverse view of the fetal upper mediastinum is as simple to obtain as the four-chamber view. It demonstrates the main pulmonary artery, ascending aorta and superior vena cava in cross- or oblique sections. The purposes of this study were to describe the normal anatomy of the three-vessel view and to analyze what anatomical changes would occur in this view when there are lesions of the ventricular outflow tracts and/or great arteries. Sonograms of 29 fetuses with lesions involving the ventricular outflow tracts and/or great arteries were reviewed. Three-vessel views were evaluated in terms of vessel size, number, arrangement and alignment. Twenty-eight of 29 fetuses showed an abnormal three-vessel view that included abnormal vessel size (n = 12), abnormal alignment (n = 8), abnormal arrangement (n = 7) and abnormal vessel number (n = 3). The vessel size was abnormal in obstructive lesions of the right (n = 4) or the left (n = 8) side of the heart. An abnormal alignment was seen in tetralogy of Fallot (n = 6) and double-outlet right ventricle (n = 2) that showed anterior displacement of the aorta. An abnormal arrangement was seen in complete (n = 4) and corrected (n = 1) transposition, double-outlet right ventricle (n = 1) and pulmonary atresia with ventricular septal defect (n = 1). Only two vessels were seen in truncus arteriosus (n = 1). Four vessels were seen in persistent left superior vena cava (n = 2). A fetus with pulmonary atresia and intact ventricular septum showed a normal three-vessel view. In conclusion, most of the lesions involving the ventricular outflow tracts and/or great arteries showed an abnormal three-vessel view.

Streptomyces linear plasmids that contain a phage-like, centrally located, replication origin

Unlike previously studied linear replicons containing 5' DNA termini covalently bound to protein, pSLA2, a 17 kb linear plasmid of Streptomyces rochei, initiates replication internally rather than at the telomeres (Chang and Cohen, 1994). Here we identify and characterize the replication origin of pSLA2, showing that it contains a series of direct repeats (iterons) within a centrally located gene encoding an essential DNA-binding protein (Rep1); a second essential protein (Rep2), which resembles prokaryotic DNA helicases and has ATPase activity stimulated by single-stranded DNA, is expressed from the same transcript. A 430 bp locus separated by almost 2 kb from the iterons of the origin specifies an as yet undefined additional function required in cis for plasmid replication. pSCL, a 12 kb linear plasmid of Streptomyces clavuligerus, contains, near the centre of the plasmid, a region configured like the pSLA2 origin. The replication regions of pSLA2 and pSCL, which are capable of propagating plasmid DNA in either a circular or linear form (Shiffman and Cohen, 1992; Chang and Cohen, 1994) resemble those of temperate bacteriophages of the Enterobacteriacae and Bacillus. Our observations suggest that Streptomyces linear plasmids may occupy an evolutionarily intermediate position between circular plasmids and linear phage replicons.

Effect of a vitamin D3 analog, EB1089, on hematopoietic stem cells from normal and myeloid leukemic blasts

The seco-steroid 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) induces differentiation and inhibits clonal proliferation of HL-60 cells. We analyzed the effect of a novel vitamin D3 analog, EB1089, on normal myeloid and leukemic cells as well as CD34+ cells. EB1089 showed an extraordinary inhibition of clonal growth of HL-60 cells (ED50 = 5 x 10(-11) M) and AML blast cells (ED50 = 9 x 10(-10) M) compared to 1,25(OH)2D3 without suppression of growth of normal human bone marrow CFU-GM. The CD34+ cells from acute myeloid leukemia (AML) blasts were inhibited in a dose-dependent fashion by 1,25(OH)2D3 with an ED50 of 1.2 x 10(-9) M; and even more strikingly, 10(-10) M of EB1089 inhibited all clonal growth of human CD34+ leukemic colony-forming cells. In contrast, both EB1089 and 1,25(OH)2D3 (10(-8) M) showed little or only mild inhibition of CD34+ clongenic hematopoietic cells from normal human peripheral blood (PB); and in liquid culture, EB1089 stimulated the proliferation of normal human CD34+ cells about 2.5 times as compared to control cultures. In order to evaluate the potential use of EB1089 for purging leukemic cells from normal CD34+ progenitor cells for PB stem cell transplantation (PBSCT), normal human PB mononuclear cells (PBMNC) were contaminated with HL-60 cells, and then CD34+ cells purified and treated with EB1089. We found that CD34+ purification and EB1089 purging was able to eliminate approximately 100% of HL-60 leukemic cells with no toxicity to normal CD34+ hematopoietic progenitor cells. These data suggested that purification of CD34+ cells and ex vivo treatment with EB1089 might provide an effective therapeutic approach for PBSCT.

Waveform-decomposition-based algorithm for horizontal parallax-only-display computer-generated holograms

A fast algorithm to compute a scattering pattern produced by a two-dimensional object is presented. Rather than by use of an approximation, this algorithm is derived by decomposition of the spherical nature of a radiation pattern into the sum of plane waves. Thus it precludes the phase errors that exist in approximationbased Fresnel holograms. Moreover, the amount of computation required in this method is shown to be significantly smaller than that of a well-known ray-tracing method; excellent performance, as good as one could obtain with the ray-tracing method, is achieved. Implementation results as well as sampling constraints are also presented.

Taurine intake of Korean breast-fed infants during lactation

i. Taurine concentrations of human milk of nonvegetarians and lacto-ovovegetarians decreased significantly during the course of lactation. Taurine concentrations in lacto-ovovegetarians after 90 days postpartum were lower than those of nonvegetarians. Taurine concentrations of human milk by 150 days postpartum were: nonvegetarian 248-434 nmol/ml (31.0-54.4 mg/L); lacto-ovovegetarian 153-418 nmol/ml (19.1-52.3 mg/L). ii. Taurine intakes in infants of lacto-ovovegetarians decreased significantly during lactation, unlike from the pattern in infants of nonvegetarians. Taurine intakes in infants of lacto-ovovegetarians at 90, 120 and 150 days postpartum were lower, compared with those in nonvegetarians. Taurine intakes in infants by 150 days postpartum were: Infants of nonvegetarians 169-229 mumol/day (21.1-28.6 mg/day); Infants of lacto-ovovegetarians 106-210 mumol/day (21.1-28.6 mg/day). iii. This study showed that the taurine concentration in human milk and the taurine intake of infants were different during lactation between nonvegetarians and lacto-ovovegetarians, and that the intake per kg body weight decreased during lactation. Results suggest that the differences observed might be due to the effect of consumption of different types of food.

Microsurgery in a rat lung transplant model: analysis of benefit

With the use of microsurgery, we have developed a method of measuring hemodynamic parameters in a rat not possible with previous technology. Three groups of rats were studied: a chemically induced pulmonary hypertensive group (PH); a chemically induced pulmonary hypertensive group treated with single lung transplantation (LT); and an untreated, control group (C). Cardiac output, heart rate, and pulmonary vascular resistance were then calculated in each group from data obtained by 1 mm high fidelity micromanometers and an ultrasonic flow probe. The results show that the data collected from the rodent model are reproducible within each group, and data quality is comparable to large animal models. With this new method, data can be collected in a small animal model at a fraction of the time and cost of large animal studies. Additionally, the complications of graft rejection in large animal studies are eliminated in an isogenic rodent model.

Heterologous expression of an engineered biosynthetic pathway: functional dissection of type II polyketide synthase components in Streptomyces species

Polyketides are an extensive class of secondary metabolites with diverse molecular structures and biological activities. A plasmid-based multicomponent polyketide synthase expression cassette was constructed using a subset of actinorhodin (act) biosynthetic genes (actI-orf1, actI-orf2, actI-orf3, actIII, actVII, and actIV) from Streptomyces coelicolor which specify the construction of the anthraquinone product aloesaponarin II, a molecule derived from acetyl coenzyme A and 7 malonyl coenzyme A extender units. This system was designed as an indicator pathway in Streptomyces parvulus to quantify polyketide product formation and to examine the functional significance of specific polyketide synthase components, including the act beta-ketoacyl synthase (beta-KS; encoded by actI-orf1 and actI-orf2) and the act cyclase/dehydrase (encoded by actVII-orf4). Site-directed mutagenesis of the putative active site Cys (to a Gln) in the actI-orf1 beta-KS product completely abrogated aloesaponarin II production. Changing the putative acyltransferase active-site Ser (to a Leu) located in the actI-orf1 beta-KS product led to significantly reduced but continued production of aloesaponarin II. Replacement of the expression cassette with one containing a mutant form of actI-orf2 gave no production of aloesaponarin II or any other detectable polyketide products. However, an expression cassette containing a mutant form of actVII-orf4 gave primarily mutactin with low-level production of aloesaponarin II.

Malignant intraventricular schwannoma. Case report

The authors present the clinical, radiological, and pathological features of a malignant schwannoma occurring in the right lateral ventricle of a 40-year-old man. Metastasis to both cerebellopontine angles and to the cerebellum was found 7 months after subtotal removal of the tumor.

Sequences of the oxytetracycline polyketide synthase-encoding otc genes from Streptomyces rimosus

The complete nucleotide sequences of the Streptomyces rimosus oxytetracycline (oxyTc) polyketide synthase (PKS)-encoding genes (otcY) has been determined, revealing three open reading frames. The deduced amino-acid sequences correspond to the presumed heterodimeric beta-ketoacyl synthase and acyl carrier protein found in other type-II (multicomponent) PKS systems that specify construction of acetate-derived polyketide antibiotics.

Analysis of type II polyketide beta-ketoacyl synthase specificity in Streptomyces coelicolor A3(2) by trans complementation of actinorhodin synthase mutants

Complementation of defined actinorhodin beta-ketoacyl synthase (KS) mutants by various other KS genes suggested that the ORF1-encoded KS may be relatively generalized in function, whereas the ORF2-encoded KS component may provide specificity in polyketide chain construction. Evidence for differential temporal-spatial expression of the actinorhodin and spore pigment KSs in Streptomyces coelicolor was obtained.

The measurement of glucose consumption in histoculture to determine effects of doxorubicin and cisplatinum on human gastric carcinoma

We have developed a chemosensitivity assay of human tumors growing on collagen-sponge-gel-supported histoculture. This assay is thus termed the Histoculture Drug Response Assay (HDRA). In the HDRA, the end points of [3H]thymidine incorporation measured by histological autoradiography and tetrazolium dye reduction were initially used and found to have good in vitro-in vivo correlations, including that determined in clinical trials. We have now developed glucose consumption as an endpoint in histoculture. We have monitored glucose consumption for 11 weeks with histocultured stomach cancer tissue that was obtained from a patient with stomach cancer metastatic to the lymph node. The histocultured lymph node specimens were treated with various concentrations of doxorubicin and cisplatinum. The glucose-consumption rate decreased with greater concentrations of both drugs. The results correlated with the thymidine labeling index. From these results, we conclude that the glucose-consumption-rate endpoint in histocultured cancer tissue is non-destructive, unlike the [3H]thymidine and tetrazolium dye end points, allowing serial determinations over extended periods in culture. Thus, the glucose consumption end point may enhance the development of optimal treatment doses and schedules. We also conclude that long-term histoculture drug response studies of metastatic stomach cancer are possible.

Sweat gland adenomas: immunohistochemical study with emphasis on myoepithelial differentiation

Thirty-one dermal appendage tumors of sweat gland differentiation including 7 spiradenomas (SPA), 8 cylindromas (CYL), 8 acrospiromas (ACS), and 8 chondroid syringomas (CS) were analyzed using antibodies to epithelial membrane antigen (EMA), cytokeratin (AE1, AE3, CAM 5.2, 34BE12), S-100 protein, actin (ACT), and desmin (DES) to characterize the immunocytochemical profile of benign sweat gland tumors. Cytokeratin expression was variable; AE1, 34BE12, AE3, and CAM 5.2 were present in 31, 24, 23, and 22 tumors respectively; 29 tumors contained EMA. Seventeen tumors, (6 SPA, 8 CYL, 2 ACS, 1 CS) stained with antibody to alpha smooth muscle actin, and 26 (7 SPA, 7 CYL, 4 ACS, 8 CS) expressed S-100 protein. Although some prior studies had reported actin filaments on electron microscopy in both spiradenoma and cylindroma, these tumors have previously been considered to be negative for myoepithelial differentiation. All spiradenomas and cylindromas we studied demonstrated actin and/or S-100 protein positivity in basal epithelial cells, consistent with myoepithelial differentiation. The organization of actin and S-100 protein positivity displayed by the spiradenomas and cylindromas we studied suggests that the tumors are differentiated towards the secretory portion of the eccrine sweat gland.

Functional replacement of genes for individual polyketide synthase components in Streptomyces coelicolor A3(2) by heterologous genes from a different polyketide pathway

Streptomyces coelicolor A3(2) and Streptomyces violaceoruber Tü22 produce the antibiotics actinorhodin and granaticin, respectively. Both the aglycone of granaticin and the half-molecule of actinorhodin are derived from one acetyl coenzyme A starter unit and seven malonyl coenzyme A extender units via the polyketide pathway to produce benzoisochromane quinone moieties with identical structures (except for the stereochemistry at two chiral centers). In S. coelicolor and S. violaceoruber, the type II polyketide synthase (PKS) is encoded by clusters of five and six genes, respectively. We complemented a series of S. coelicolor mutants (act) defective in different components of the PKS (actI for carbon chain assembly, actIII for ketoreduction, and actVII for cyclization-dehydration) by the corresponding genes (gra) from S. violaceoruber introduced in trans on low-copy-number plasmids. This procedure showed that four of the act PKS components could be replaced by a heterologous gra protein to give a functional PKS. The analysis also served to identify which of three candidate open reading frames (ORFs) in the actI region had been altered in each of a set of 13 actI mutants. It also proved that actI-ORF2 (whose putative protein product shows overall similarity to the beta-ketoacyl synthase encoded by actI-ORF1 but whose function is unclear) is essential for PKS function. Mutations in each of the four complemented act genes (actI-ORF1, actI-ORF2, actIII, and actVII) were cloned and sequenced, revealing a nonsense or frameshift mutation in each mutant.

Serum alkaline phosphatase and inorganic phosphorus values in spinal cord injury patients with heterotopic ossification

The blood chemistry was studied in 140 spinal cord injury (SCI) patients (acute injury ward), including 18 patients who developed heterotopic ossification (HO). Comparisons between the HO and non-HO groups were made to determine if the alkaline phosphatase (AP), inorganic phosphorus (P), or calcium (Ca) levels were of diagnostic value. The results showed that AP, P, and Ca by themselves were of little help in the diagnosis of HO. However, the combination of elevated AP and P was significant, especially if both were consistently elevated. There were no significant differences between the HO and non-HO groups concerning completeness or level of spinal injury.

Development of a high-performance liquid chromatography assay method and characterization of adenosine diphosphate-ribosylarginine hydrolase in skeletal muscle

A new HPLC assay method for the enzyme that cleaves the bond between ADP-ribose and arginine was developed by using ADP-ribose-4-dimethylaminoazobenzene-4-sulfonyl arginine methyl ester (ADP-R-DABS-AME) as a substrate analog. Because of the difference of hydrophobicity, ADP-R-DABS-AME and DABS-AME elute as well-separated peaks on the C-18 reversed-phase HPLC column, which is monitored at 475 nm. Because ADP-R-DABS-AME gives two peaks of alpha and beta anomers on the C-18 HPLC column, the stereospecificity of ADP-ribosylarginine hydrolase can be easily determined. By using this new assay method, the existence of ADP-ribosylarginine hydrolase was identified in cultured chicken muscle cells. This enzyme activity was also found in rat and rabbit skeletal muscle. The muscle hydrolase cleaves the alpha anomer of ADP-R-DABS-AME specifically and requires magnesium and dithiothreitol for its full activation. By using this HPLC assay method, ADP-ribosylarginine hydrolase activity was also found in the crude extracts from the rat heart, liver, kidney, and brain.

Abnormal cervical cytology leading to the diagnosis of gastric cancer

There have been nine cases reported in the English literature in which the finding of malignant cells on cervical/vaginal cytology led to the diagnosis of primary gastric cancer. We report on a patient with gastric carcinoma, metastatic to the cervix, in which the diagnosis was suspected by the finding of signet ring cells on a Papanicolaou smear of the cervix. Prior to treatment of this patient, concordance of signet ring carcinoma on cervical and ascitic fluid cytology and on cervical and gastric biopsies was documented; this has not been reported previously. Thirty-four additional cases of gastric carcinoma metastatic to the cervix are reviewed. This paper is presented to remind the clinician that, however rare, metastases from the gastrointestinal tract to the uterine cervix do occur.

Linear phase-conjugate oscillator employing a photorefractive crystal

Using Yeh's analytic method [J. Opt. Soc. Am. A 2, 727 (1985)] we derive the oscillation conditions of a linear phaseconjugate oscillator consisting of a photorefractive crystal and two conventional mirrors. For the special case of a 90-rad phase shift, the threshold oscillation conditions of the linear phase-conjugate oscillator are derived as a function of cavity length. The results indicate that, unlike in the case of a phase-conjugate oscillator employing a Kerr-like material, in which oscillation can occur for any cavity length, oscillation can occur in this case only for specified ranges of the cavity length determined by the coupling strength. We also show that for larger coupling strengths oscillation can occur over wider ranges of the cavity length.