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An essay is presented that tackles slavery tourism in the U.S. as of March 2015. It cites the guidebook "Louisiana's Haunted Plantations," by Jill Pascoe, which focuses on the ghost of an alleged slave named Sally Boston. It claims that in the haunted plantation tourism, the slave's enslavement is continued to perpetuity. Also cited are the comments by Frank Wilderson, III and Orlando Patterson on the issues on slavery.

The etiology of stroke in children with sickle cell anemia (SCA) is complex and poorly understood. Growing evidence suggests that genetic factors beyond the sickle cell mutation influence stroke risk in SCA. We previously reported risk associations with polymorphisms in several proinflammatory genes in SCA children with ischemic stroke. The aim of this replication study was to confirm our previous findings of associations between the TNF(−308) G/A, IL4R 503 S/P, and ADRB2 27 Q/E polymorphisms and large vessel stroke risk.

Isopentenyl diphosphate (IPP), which is produced from mevalonic acid or other nonmevalonic substrates, is the universal precursor of isoprenoids in nature. Despite the presence of several isoprenoid compounds in plastids, enzymes of the mevalonate pathway leading to IPP formation have never been isolated or identified to our knowledge. We now describe the characterization of two pepper (Capsicum annuum L.) cDNAs, CapTKT1 and CapTKT2, that encode transketolases having distinct and dedicated specificities. CapTKT1 is primarily involved in plastidial pentose phosphate and glycolytic cycle integration, whereas CapTKT2 initiates the synthesis of isoprenoids in plastids via the nonmevalonic acid pathway. From pyruvate and glyceraldehyde-3-phosphate, CapTKT2 catalyzes the formation of 1-deoxy-xylulose-5-phosphate, the IPP precursor. CapTKT1 is almost constitutively expressed during the chloroplast-to-chromoplast transition, whereas CapTKT2 is overexpressed during this period, probably to furnish the IPP necessary for increased carotenoid biosynthesis. Because deoxy-xylulose phosphate is shared by the plastid pathways of isoprenoid, thiamine (vitamin B1), and pyridoxine (vitamin B6) biosynthesis, our results may explain why albino phenotypes usually occur in thiamine-deficient plants.

Plant cells synthesize a myriad of isoprenoid compounds in different subcellular compartments, which include the plastid, the mitochondria, and the endoplasmic reticulum cytosol. To start the study of the regulation of these parallel pathways, we used pepper (Capsicum annuum) fruit as a model. Using different isoprenoid biosynthetic gene probes from cloned cDNAs, we showed that only genes encoding the plastid enzymes (geranylgeranyl pyrophosphate synthase, phytoene synthase, phytoene desaturase, and capasanthin-capsorubin synthase) are specifically triggered during the normal period of development, at the ripening stage. This pattern of expression can be mimicked and precociously induced by a simple wounding stress. Concerning the cytosol-located enzymes, we observed that the expression of the gene encoding farnesyl pyrophosphate synthase is constitutive, whereas that of farnesyl pyrophosphate cyclase (5-epi-aristolochene synthase) is undetectable during the normal development of the fruit. The expression of these later genes are, however, only selectively triggered after elicitor treatment. The results provide evidence for developmental control of isoprenoid biosynthesis occurring in plastids and that cytoplasmic isoprenoid biosynthesis is regulated, in part, by environmental signals.

Changes in high-density lipoprotein (HDL) subclass distribution were evaluated in a group of premature infants during the early postnatal period to ascertain whether enteral feeding brought about a rapid shift from neonatal to adult-like distributions. All infants were fed a combination of breast milk and formula. Cord blood of premature infants had a predominance of large, less dense (HDL2b)ggeand a paucity of intermediate-sized (HDL3a)ggeparticles. Lack of a peak in the (HDL3a)ggeis a characteristic feature for cord blood, whereas a prominent (HDL3a)ggepeak is characteristic of adult plasma. After the start of enteral feeding, blood was obtained at two time-points: 6–14 days (sample A) and 17–32 days (sample B) postdelivery. With the onset of feeding, triglyceride increased significantly from an average of 34 mg/dl in cord blood to 120 mg/dl in sample B, and cholesterol increased from 86 to 112 mg/dl in the same period. Increases in plasma lipid concentrations were paralleled by a redistribution of subclasses such that three components of almost equal intensity were evident in sample B; these consisted of (HDL2b)gge, (HDL2a2)gge, and (HDL3b)gge. A paucity of (HDL3a)ggeparticles persisted even after onset of enteral feeding; thus, increases in plasma triglyceride and cholesterol per se are not sufficient to induce the adult-like distribution. It is suggested that development of the normal adult HDL subclass pattern is complex and is probably related to the development and interaction of several factors, including plasma enzymes involved in lipid hydrolysis and esterification, lipid exchange proteins, and hormonal status.

gamma-Tocopherol methyltransferase was solubilized and purified from Capsicum chromoplast membranes by a combination of standard fractionation techniques. The purified enzyme was electrophoretically homogeneous, and its molecular weight, determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was 33,000. In the absence of detergent, the enzyme formed high molecular weight aggregates. Several properties of the enzyme have been determined. The Km values were 2.5 and 13.7 microM for S-adenosylmethionine and gamma-tocopherol, respectively. The enzyme was able to transfer the methyl group S-adenosylmethionine to N-4-azido-2-nitrophenyl-beta-alanyl-gamma-tocopherol. The rate of transfer was less efficient compared to gamma-tocopherol. In the presence of ultraviolet light, this analog inhibited the gamma-tocopherol methyltransferase activity.

ABSTRACT: Changes in high-density lipoprotein (HDL) subclass distribution were evaluated in a group of premature infants during the early postnatal period to ascertain whether enteral feeding brought about a rapid shift from neonatal to adult-like distributions. All infants were fed a combination of breast milk and formula. Cord blood of premature infants had a predominance of large, less dense (HDL2b)ggeand a paucity of intermediate-sized (HDL3a)ggeparticles. Lack of a peak in the (HDL3a)ggeis a characteristic feature for cord blood, whereas a prominent (HDL3a)ggepeak is characteristic of adult plasma. After the start of enteral feeding, blood was obtained at two time-points: 6–14 days (sample A) and 17–32 days (sample B) postdelivery. With the onset of feeding, triglyceride increased significantly from an average of 34 mg/dl in cord blood to 120 mg/dl in sample B, and cholesterol increased from 86 to 112 mg/dl in the same period. Increases in plasma lipid concentrations were paralleled by a redistribution of subclasses such that three components of almost equal intensity were evident in sample B; these consisted of (HDL2b)gge, (HDL2a2)gge, and (HDL3b)gge. A paucity of (HDL3a)ggeparticles persisted even after onset of enteral feeding; thus, increases in plasma triglyceride and cholesterol per se are not sufficient to induce the adult-like distribution. It is suggested that development of the normal adult HDL subclass pattern is complex and is probably related to the development and interaction of several factors, including plasma enzymes involved in lipid hydrolysis and esterification, lipid exchange proteins, and hormonal status.

Later steps of carotenoid biosynthesis catalyzed by cyclase enzymes involve the formation of α, β, and κ-rings. Examination of the primary structure of lycopene β-cyclase revealed 55% identity with that of antheraxanthin κ-cyclase. Recombinant lycopene β-cyclase afforded only β-carotene, while recombinant antheraxanthin κ-cyclase catalyzed the formation of β-carotene from lycopene as well as the conversion of antheraxanthin into the κ-carotenoid capsanthin. Since the formation of β- and κ-rings involves a transient carotenoid carbocation, this suggests that both cyclases initiate and/or neutralize the incipient carbocation by similar mechanisms. Several amine derivatives protonated at physiological pH were used to examine the molecular basis of this phenomenon. The β- and κ-cyclases displayed similar inhibition patterns. Affinity or photoaffinity labeling usingp-dimethylamino-benzenediazonium fluoroborate,N,N-dimethyl-2-phenylaziridinium, and nicotine irreversibly inactivated both cyclase enzymes. Photoaffinity labeling using [3H]nicotine followed by radiosequence analysis and site-directed mutagenesis revealed the existence of two cyclase domains characterized by the presence of reactive aromatic and carboxylic amino acid residues. We propose that these residues represent the “negative point charges” involved in the coordination of the incipient carotenoid carbocations.

Cells of the intestinal mucosa of the infant and adult rat maintain a pattern of continuous growth, accumulating structural and functional proteins and lipids while migrating the length of the villus column. Cells of jejunal and ileal segments were fractionated sequentially from villus tip to inner crypt and distribution patterns were determined for DNA, total protein, cholesterol, phospholipid, and disaccharidases. Patterns of increasing ratios of protein, lipids, and disaccharidases to DNA were maintained to villus tips, with only slight fall-off of enzymes observed. Distribution profiles of disaccharidases, when computed relative to protein (as seen in previous reports), show distortion of the true cellular distribution pattern of these enzymes as determined by the DNA content of the fractions. Wide variation in cell protein concentrations was evident between jejunal and ileal segments in pre- and postweaned rats. Ileal cells of the suckling rat contained particularly high protein concentrations, which appeared to be largely transitory in nature and related to food intake. Cholesterol and phospholipids were found to be concentrated in the microvillus membrane and account for a significantly large fraction of the cellular content of these lipids.

The expression of genes involved in plastid differentiation is subject to developmental control. To understand better the molecular basis of this regulation, we have analyzed in parallel the changes in relative levels of four chloroplast and two nuclear transcripts during differentiation of chloroplasts into chromoplasts in ripening bell pepper fruits and in maturing sunflower petals, as well as in the case of chemically-induced chromoplast formation in leaves. Amongst the prominent features, we noted that transcripts of nuclear genes coding for chloroplast proteins, such as the major chlorophyll a/b-binding protein (encoded by cab) and the small subunit of ribuloses-1,5-bisphosphate carboxylase (encoded by rbcS), were detected in chromoplast-containing bell pepper leaves and sunflower petals, whilst they disappeared in bell pepper fruit chromoplasts. Transcripts of the plastid gene coding for the large subunit of ribulose-1,5-bisphosphate carboxylase were detected during the whole differentiation process. The steady-state level of the mRNA corresponding to the 32 kDa herbicide-binding protein increased in fruit and petal chromoplasts. Changes in the relative transcriptional activities of plastid genes and in their relative mRNA levels occurred during bell pepper fruit ripening. However, no significant change in the overall transcriptional activity was found when comparing both types of plastids, whereas dramatic changes in translational activity occur, indicating the prevalence of translational control of plastid gene expression in the chromoplast differentiation process.

Structural evidence has accumulated suggesting that fusion and/or translocation factors are involved in plastid membrane biogenesis. To test this hypothesis, we have developed an in vitro system in which the extent of fusion and/or translocation is monitored by the conversion of the xanthophyll epoxide (antheraxanthin) into the red ketocarotenoid (capsanthin). Only chromoplast membrane vesicles from red pepper fruits (Capsicum annuum) contain the required enzyme. Vesicles prepared from the mutant yellow cultivar are devoid of this enzyme and accumulate antheraxanthin. The fusion and/or translocation activity is characterized by complementation due to the synthesis of capsanthin and the parallel decrease of antheraxanthin when the two types of vesicles are incubated together in the presence of plastid stroma. We show that the extent of conversion is dependent upon an ATP-requiring protein that is sensitive to N-ethylmaleimide. Further purification and immunological analysis have revealed that the active factor, designated plastid fusion and/or translocation factor (Pftf), resides in a protein of 72 kDa. cDNA cloning revealed that mature Pftf has significant homology to yeast and animal (NSF) or bacterial (Ftsh) proteins involved in vesicle fusion or membrane protein translocation.

Pepper (Capsicum annuum) beta-cyclohexenyl xanthophyll epoxidase cDNA was cloned and the corresponding enzyme overexpressed and purified from Escherichia coli, for investigation of its catalytic activity. The recombinant protein did not directly accept NADPH for epoxidation of cyclohexenyl carotenoids, nor did it operate according to a peroxygenase-based mechanism. Instead, the reducing power of NADPH was transferred to the epoxidase via reduced ferredoxin as shown by reconstitution of epoxidase activity in the presence of NADPH, ferredoxin oxidoreductase, and ferredoxin. Bacterial rubredoxin could be substituted for ferredoxin. The pepper epoxidase acted specifically on the beta-ring of xanthophylls such as beta-cryptoxanthin, zeaxanthin, and antheraxanthin. The proposed reaction mechanism for epoxidation involves the formation of a transient carbocation. This characteristic allows selective inhibition of the epoxidase activity by different nucleophilic diethylamine derivatives, p-dimethylaminobenzenediazonium fluoroborate and N,N-dimethyl-2-phenylaziridinium. It was also shown that the epoxidase gene was up-regulated during oxidative stress and when chloroplasts undergo differentiation into chromoplasts in pepper fruit.

Phytoene is the first C40intermediate in the biogenesis of carotenoids. It is formed by two enzyme activities, catalyzing (i) the coupling of two molecules of geranylgeranyl diphosphate to yield prephytoene diphosphate and (ii) the conversion of prephytoene diphosphate into phytoene. We show now, with Capsicumchromoplast stroma, that the overall activity resides in a single protein, which has been purified to homogeneity by affinity chromatography. The monomeric structure and the molecular size (Mr47,500) were demonstrated by NaDodSO4/PAGE and glycerol gradient centrifugation. Further characterization was achieved by using specific antibodies which allowed immunofractionation and immunoprecipitation of the enzymatic activity from chromoplast stroma. The two reactions followed conventional Michaelis-Menten kinetics, with Kmvalues of 0.30 μM and 0.27 μM, respectively, for geranylgeranyl diphosphate and prephytoene diphosphate. The activity of the enzyme depends strictly upon the presence of Mn2+. This selectivity may be one of the factors regulating the competition with potentially rival enzymes converting geranylgeranyl diphosphate into other plastid terpenoids. The two enzymatic reactions were inhibited by inorganic pyrophosphate and by the arginine-specific reagent hydroxyphenylglyoxal. In no instance were the two reactions kinetically uncoupled. These properties strongly suggest that the same enzyme catalyzes the two consecutive reactions, and we propose to name it phytoene synthase.

The biosynthesis of phylloquinone (vitamin K1) was examined using Capsicum fruit chloroplasts and chromoplasts (apparently phylloquinone free). In both cases, the synthesis of phylloquinone from a-naphthoquinone, dihydro-a-naphthoquinone, 1,4-dihydroxy-2-naphthoic acid (as precursors of the ring moiety) and (S)-adenosyl-L-methionine was achieved. In the presence of phytylpyrophosphate, the biosynthesis of phylloquinone in both organelles is particularly enhanced when 1,4-dihydroxy-2-naphthoic acid is used.

Cryptochromes are blue-light absorbing flavoproteins with many important signaling roles in plants, including in de-etiolation, development, and stress response. They interact with downstream signaling partners such as transcription factors and components of the proteasome, and thereby alter regulation of nuclear gene expression in a light dependent manner. In a prior study, it has also been shown that Arabidopsis cry1 activation by blue light results in direct enzymatic conversion of molecular oxygen (O2) to ROS (reactive oxygen species) in vivoleading to cell death in overexpressing lines. Here we extend these observations to show that Atcry2 is translocated from the cytosol to the nucleus in response to blue light illumination, resulting in nuclear accumulation of ROS in expressing insect cell cultures. These observations suggest that ROS formation may represent a novel means of signaling by Atcry2 distinct from, and perhaps complementary to, the currently known mechanism of light-mediated conformational change.

Rishitin accumulation as well as its biosynthesis from added [2-14C]MVA was observed in tomato cell suspension cultures elicited by yeast extract.

Trichomonas vaginalis is rarely associated with urinary tract infections in neonates. In the few cases reported T. vaginalis was present simultaneously with bacterial agents. We report an infant in whom T. vaginalis was identified as the sole pathogen.

Through the use of Capsicum chromoplast membranes, we report for the first time the direct methylation of γ-tocopherol into α-tocopherol in the presence of S-adenosylmethionine. Furthermore the S-adenosylmethionine: γ-tocopherol methyltransferase activity has been solubilized. On a protein basis, the activity recovered in the soluble preparation was higher than that bound to the membranes.

Background: The etiology of stroke in sickle cell anemia (SCA) is complex and multiple genetic factors outside of the sickle gene undoubtedly contribute to stroke risk in SCA. Simultaneous analyses of multiple genetic variants may therefore be more informative than evaluation of individual candidate genes. Moreover, stroke in SCA is phenotypically heterogeneous, varying from large cortical vessel (LV) distribution infarcts to milder lacunar infarcts due to small vessel disease, suggesting distinct pathogenetic mechanisms for stroke in SCA. We previously reported risk associations with particular TNFA, IL4R and ADRB2 polymorphisms in children enrolled in the CSSCD. Methods: To confirm our previous findings from the CSSCD and identify other potential “susceptibility” loci that may influence the development of LV stroke, we extended our investigations to SCA children who participated in the Stroke Prevention Trial in Sickle Cell Anemia (STOP). Children with MRA evidence of obstruction or stenosis of one or more large vessels (LV disease) were compared with untransfused children with a normal MRA. Ninety-seven patients were included in this study. Of the 119 patients originally enrolled in STOP, 77 (30 MRA+, 47 MRA−) were eligible for this study and were analyzed together with a local sample of 20 MRA(+)patients. Genotyping for 110 polymorphisms among 65 candidate cardiovascular and proinflammatory genes was performed using multiplex linear array methods. Of the 110 variant sites examined, 95 were sufficiently polymorphic to permit statistical testing, using 2 x 2 exact tests. Results: When comparing MRA(+) patients with MRA(−) patients, 9 of the polymorphic loci revealed nominally significant differences (P<0.10): TNF(−308), IL4(−589), ADRB2 16, ICAM1 56, APOC3(−482), LPL 93, AGT 235, and MMP3(−1171). For TNF G(−308)A, the frequency of the G allele was 80%, consistent with allele frequency data in African-Americans. In the current study, there was a relative excess of children with the GG genotype in the MRA(+) group compared to the MRA(−) group (OR= 2.48; p = 0.037). These results, showing the TNF(−308) locus to be predictive of LV vasculopathy, are virtually identical to our previous findings in the CSSCD population and confirm that the TNF gene plays a significant role in stroke risk. The TNF gene lies within the HLA region, making this finding particularly intriguing in light of our previous data indicating HLA associations with stroke risk. Detailed studies of this region are now necessary to determine if it is indeed the TNF locus or other genes in linkage disequilibrium that are responsible for this association.