Retention mechanism of imidazoles in connective tissue. III. Aldehyde adduct formation of a 4(5H)(or5(4H))-imidazolone product in vitro

2-Methylimidazole (2MI), as well as imidazole, has been thought to undergo cupro-ascorbate (Cu-VC)-catalyzed oxidative transformation in vitro to become a reactive species capable of combining with aldehydes intrinsic to connective-tissue proteins. We attempted to seize the essence of the above reaction through obtaining the structural information of an aldehyde-bonding species. As major products from 2MI in the in vitro Cu-VC system, 2-hydroxymethylimidazole (2(OH)MI) and 2-methyl-4(5H)(or 5(4H))-imidazolone (2MIone) were identified by mass-spectral and chromatographic comparison with the corresponding authentic standards synthesized. The in situ addition of acetaldehyde or propionaldehyde as a simple protein-aldehyde model to the system resulted in the deducible formation of an aldol condensate, 2-methyl-4(or 5)-ethylidene-4(5H)(or 5(4H))-imidazolone (2MEIone) or its possible analogue with a propylidene moiety, respectively. The authentic compound of 2MIone directly reacted with acetaldehyde and easily afforded the products assignable to the isomers of 2MEIone through the ethylidene moiety at physiological pH and temperature, whereas neither 2MI or 2(OH)MI reacted at all. These results suggest that a 4(5H)(or 5(4H))-imidazolone product, although simply a monooxygenated form, is sufficiently reactive to give aldol condensation-typed covalent adducts with aldehydes, even under physiological conditions, probably having an activated methylene moiety in the ring structure. Based on the present results, we discussed the mechanism of the retention of imidazole-containing drugs in connective tissue.

[Delineation of the white and gray matter of the normal human cervical spinal cord using diffusion-weighted echo planar imaging]

To delineate the white and gray matter of the normal human cervical spinal cord, diffusion-weighted echo planar imaging (DW-EPI) was performed in 11 healthy volunteers. Three axial (X-, Y- and Z-axis) anisotrophic diffusion-weighted images were obtained on a 1.5T superconducting clinical unit using a single-shot DW-EPI sequence. On X- and Y-axis DWIs the white and gray matter could be well differentiated: the former showed high intensity and the latter low intensity. Anterior columns were clearly visible, whereas posterior columns were not. On Z-axis DWI the white and gray matter could not be differentiated at all, because both showed low intensity. In conclusion, DW-EPI can clearly delineate the white and gray matter of the cervical spinal cord, and this technique will be useful to evaluate white matter disorders such as ischemic or demyelinating disease.

Detection of carcinoembryonic antigen mRNA in the mesenteric vein of patients with resectable colorectal cancer

The detection of tumor cells in the drainage venous blood of patients with colorectal cancer was made feasible by demonstrating carcinoembryonic antigen (CEA) mRNA in the mononuclear cell component of the blood, using a nested reverse transcription-polymerase chain reaction. CEA mRNA was detected in the drainage venous blood from 11 (42%) of 26 patients, and the rate of detection increased according to the grade of vessel invasion. CEA mRNA was detected in all patients with synchronous liver metastases, even though there was no significant correlation between the presence of CEA mRNA in the drainage venous blood and the clinicopathological findings. As the presence of CEA mRNA in the drainage venous blood is an indicator of the spread of tumor cells in patients with colorectal cancer, this assay can be used to assess the possible outcome of patients with colorectal cancer, providing one more tool for the physician-oncologist to use in designing appropriate treatments.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

Promoter elements required for sugar-repression of the RAmy3D gene for alpha-amylase in rice

There is increasing evidence showing that cereal alpha-amylase gene expression is controlled not only by the classical hormonal regulation, but also by feed-back sugar repression. We demonstrated by in situ hybridization that the sugar repression of rice alpha-amylase gene RAmy3D takes place in scutellar epithelium cells of callus-forming rice embryos. We also used a transient expression system to study the cis-acting elements involved in the sugar repression of the RAmy3D promoter activity. Site-directed mutagenesis of the 50-bp nucleotide sequence from -172 to -123 revealed that consensus sequences of G motif (TACGTA) and TATCCA T/C motif (GATA motif as its antisense sequence) are responsible for sugar repression. The promoter sequences required for sugar repression are reported and discussed.

Sugar sensing and alpha-amylase gene repression in rice embryos

We used a transient expression system to study the mechanism by which carbohydrates repress a rice (Oryza sativa L.) alpha-amylase (EC 3.2.1.1) gene. Exogenously fed metabolizable carbohydrates are able to elicit repression of the alpha-amylase gene RAmy3D in the rice embryo, and our results indicate that repression is also triggered efficiently by endogenous carbohydrates. Glucose analogs that are taken up by plant cells but not phosphorylated by hexokinase are unable to repress the alpha-amylase gene studied, while 2-deoxyglucose, which is phosphorylable but not further metabolized, down-regulates RAmy3D promoter activity, indicating a role for hexokinase in the sugar-sensing mechanism triggering repression of the RAmy3D gene. We tested two different hexokinase inhibitors, mannoheptulose and glucosamine, but only the latter was able to relieve RAmy3D promoter activity from repression by endogenous carbohydrates. This correlates with the higher ability of glucosamine to inhibit the activity of rice hexokinases in vitro. The glucosamine-mediated relief of RAmy3D promoter activity from repression by endogenous carbohydrates does not correlate with a reduced rate of carbohydrate utilization.

Functional dissection of a sugar-repressed alpha-amylase gene (RAmy1 A) promoter in rice embryos

The gibberellin-inducible rice alpha-amylase gene, RAmy1 A, was demonstrated to be sugar repressed in rice embryos and functional dissection of the promoter of RAmy1 A in relation of its sugar-modulated expression was performed. Gibberellin-response cis-elements of GARE (TAACAAA) and pyrimidine box (CCTTTT) were partially involved in the sugar repression.

Serologic and phylogenetic characterization of HIV-1 subtypes in Uganda

OBJECTIVES

To determine the HIV genetic subtypes present in HIV-1-infected asymptomatic blood donors in Uganda and to evaluate serologic detection of infection by commercial immunoassays; to evaluate samples for HIV-1 group O infections.

METHODS

Sixty-four HIV-seropositive plasma samples were collected from the Nakasero Blood Bank, Kampala, Uganda. The plasma were evaluated using commercial HIV enzyme immunoassays (EIA) and a research immunoblot. HIV-1 group M and O infections were identified on the basis of discordant seroreactivity in EIA and reactivity to group M and O antigens on the immunoblot. Regions of gag p24 and env gp41 were amplified using reverse transcriptase polymerase chain reaction, and genetic subtypes were determined by phylogenetic analysis.

RESULTS

Serologic testing confirmed that 63 out of 64 plasma units were positive for HIV-1 group M infection and showed no evidence of HIV-1 group O infections. Genetic subtyping determined that 25 samples were subtype A, three subtype C, 22 subtype D, and nine were heterogeneous for subtypes A and D.

CONCLUSIONS

Despite the sequence variation observed in Uganda, commercial EIA based on HIV-1 subtype B proteins detected all the infections. In contrast, a peptide-based assay failed to detect three infections by subtype D viruses. This emphasizes the negative impact of HIV genetic variation on assays that rely on peptides to detect HIV infections. The number of infections with heterogeneous subtype (due to mixed infections or recombinant viruses) is high and reflects the growing complexity of the HIV epidemic in endemic regions where multiple subtypes are present in the population.

Sugar Repression of a Gibberellin-Dependent Signaling Pathway in Barley Embryos

Increasing evidence shows that sugars can act as signals affecting plant metabolism and development. Some of the effects of sugars on plant growth and development suggest an interaction of sugar signals with hormonal regulation. We investigated the effects of sugars on the induction of [alpha]-amylase by gibberellic acid in barley embryos and aleurone layers. Our results show that sugar and hormonal signaling interact in the regulation of gibberellic acid-induced gene expression in barley grains. The induction of [alpha]-amylase by gibberellic acid in the aleurone layer is unaffected by the presence of sugars, but repression by carbohydrates is effective in the embryo. [alpha]-Amylase expression in the embryo is localized to the scutellar epithelium and is hormone and sugar modulated. The effects of glucose are independent from the effects of sugars on gibberellin biosynthesis. They are not due to an osmotic effect, they are independent of abscisic acid, and only hexokinase-phosphorylatable glucose analogs are able to trigger gene repression. Overall, the results suggest the existence of an interaction between the hormonal and metabolic regulation of [alpha]-amylase genes in barley grains.

Sugar Repression of a Gibberellin-Dependent Signaling Pathway in Barley Embryos

Increasing evidence shows that sugars can act as signals affecting plant metabolism and development. Some of the effects of sugars on plant growth and development suggest an interaction of sugar signals with hormonal regulation. We investigated the effects of sugars on the induction of [alpha]-amylase by gibberellic acid in barley embryos and aleurone layers. Our results show that sugar and hormonal signaling interact in the regulation of gibberellic acid-induced gene expression in barley grains. The induction of [alpha]-amylase by gibberellic acid in the aleurone layer is unaffected by the presence of sugars, but repression by carbohydrates is effective in the embryo. [alpha]-Amylase expression in the embryo is localized to the scutellar epithelium and is hormone and sugar modulated. The effects of glucose are independent from the effects of sugars on gibberellin biosynthesis. They are not due to an osmotic effect, they are independent of abscisic acid, and only hexokinase-phosphorylatable glucose analogs are able to trigger gene repression. Overall, the results suggest the existence of an interaction between the hormonal and metabolic regulation of [alpha]-amylase genes in barley grains.

Local tissue irritating effects and adjuvant activities of calcium phosphate and aluminium hydroxide with different physical properties

Effects of calcium phosphate and aluminium hydroxide adjuvants with different physical properties were examined in guinea pigs for local histopathological reactions, electron-microscopical changes of macrophages and adjuvanticity on total IgG antibody response to subcutaneously administered ovalbumin (OVA) and tetanus toxoid (TT). Calcium phosphate gel (Ca-gel) induced active inflammatory reactions consisting of neutrophils (pseudoeosinophils) and foamy macrophages associated with many multinuclear giant cells for at least 4 weeks. Aluminium hydroxide gel (Al-gel) also elicited granulomatous inflammatory reactions consisting mainly of macrophages with foamy cytoplasm, small lymphocytes and giant cells at the injection sites for up to 8 weeks or longer. Severity of local tissue irritation due to calcium phosphate gel (Ca-gel) was similar to that due to Al-gel except for the duration of the inflammatory reactions. Calcium phosphate suspension (Ca-sus)-induced local reactions completely ceased by the 4th week, while aluminium hydroxide suspension (Al-sus)-induced reactions were seen up to the 8th week. Electron-microscopical observations showed that both Al-gel and Al-sus caused damage of macrophages. The adjuvant activity of Al-gel for OVA or TT was significantly stronger than that of any other adjuvant material, whereas those of Ca-gel and Ca-sus were not seen at a dose of 3 mg calcium phosphate per millilitre. Al-sus-TT at a dose of 3 mg aluminium hydroxide per millilitre induced very low levels of antibody. These results suggest that calcium phosphate adjuvant may not be an useful alternative to Al adjuvant.

Electronmicroscopic study of human herpesvirus 6-infected human T cell lines superinfected with human immunodeficiency virus type 1

Human herpesvirus 6 (HHV-6) has been proposed as one of the co-factors responsible for the development of acquired immunodeficiency syndrome (AIDS) in human immunodeficiency virus (HIV) carriers. We analyzed the interaction between HHV-6 and HIV-1 in superinfected cells. Cell-free HIV-1 could superinfect human T cell lines, MT-4 and Molt-4, which had been previously infected with HHV-6. Both HHV-1 and HHV-6 replicated in the same cells. We observed two types of morphologically distinguished cells as early as 4 days after superinfection. One type (D) was degenerate cells with intracellular and extracellular HHV-6 and with less HIV-1 virions. The other type (I) was relatively intact cells with both HIV-1 and HHV-6 virions. Replication of HIV-1 was more active in the type I as compared with type D cells. The level of HIV-1 reverse transcriptase (RT) activity in the culture supernatants of cells superinfected on day 0 declined after day 7, while that in the supernatants of cell cultures infected with HIV-1 alone remained high between days 12 and 40. These results suggest that the superinfection of the HHV-6-infected cells with HIV-1 may induce a degenerative process in these cells.

Impact of pretransplantation GB virus C infection on the outcome of renal transplantation

Among renal transplant recipients with posttransplantation liver disease, the etiology remains unknown in 10 to 16% of patients. The discovery of yet another parenterally transmitted hepatitis virus, GB virus C (GBV-C), has opened avenues to study the prevalence and risk factors for GBV-C infection among patients undergoing renal transplantation and its impact on posttransplantation clinical outcomes. A cohort of 103 randomly selected recipients of kidneys were examined from anti-hepatitis C virus (HCV)-negative donors between 1986 and 1990. Pretransplantation sera were available in 99 of 103 (96%) recipients and were tested for anti-HCV, using a second-generation ELISA, and for GBV-C RNA by reverse transcription PCR. Pretransplantation GBV-C RNA was present in 18 of 99 (18%, 95% confidence interval [CI], 17.2 to 18.8%) recipients. GBV-C RNA was present in 5 of 22 (23%) anti-HCV-positive recipients compared with 13 of 77 (17%) anti-HCV-negative recipients (P = 0.53). The median number of pretransplantation blood transfusion among recipients with GBV-C RNA before transplantation was significantly higher than among recipients without GBV-C RNA (10 versus 7, P = 0.05). Posttransplantation liver disease and non-A, non-B hepatitis (NANBH) was observed in 35 and 18%, respectively, of GBV-C RNA-positive recipients compared with 28 and 10%, respectively, of GBV-C RNA-negative recipients. Using Cox regression analysis, the relative risk (RR) of posttransplantation liver disease among recipients with GBV-C RNA before transplantation was 1.37 (95% CI, 0.55 to 3.41), and posttransplantation NANBH was 2.09 (95% CI, 0.64 to 6.79). The RR of graft loss and death were not increased (0.88 and 0.92, respectively). When adjusted for pretransplantation anti-HCV, the RR of posttransplantation liver disease, NANBH, graft loss, and death did not change appreciably. In summary, although a higher risk of posttransplantation liver disease was observed among recipients with pretransplantation GBV-C infection, the analyses presented here do not allow for a precise estimate of this risk.

Intracytoplasmic chromophobe inclusion bodies in an anaplastic meningioma

Intracytoplasmic inclusion bodies are rarely found in meningiomas. A 74-year-old woman had an anaplastic meningioma with intracytoplasmic chromophobe inclusion bodies (CIB) histologically. These CIB were various shapes, e.g. round, teardrop-like, fusiform, horse-shoe-like, crescentic and perinuclear. The size of CIB ranged from 7 to 14 microns and the nuclei of the tumor cells with CIB were often eccentric. Most CIB were immunopositive only for vimentin, staining more intensely than surrounding cytoplasm in a comparative study using adjacent sections stained with hematoxylin-eosin and vimentin. CIB showed loosely textured filamentous structures which were in parallel and entangled arrangements ultrastructurally. The diameter of the filaments was 13-14 nm and they were thicker than normal intermediate filaments. Moreover, these filaments appeared to be studded with granular and fuzzy substances. These findings suggest that CIB are mainly composed of abnormally synthesized and arranged vimentin filaments.

Molecular analyses of HIV-1 group O and HIV-2 variants from Africa

Genetic variation among HIV isolates creates challenges for their detection by serologic and genetic techniques. To characterize the sequence variation and its correlation to serologic diversity of HIV-1 Group O and HIV-2 isolates, samples were identified by differential reactivity in selected commercial and research assays. Analysis of sera from Equatorial Guinea (EG) led to identification of 4 HIV-1 Group O variants. Viral RNA, extracted from these samples was used to PCR amplify overlapping sequences of the entire envelope gene using multiple primer pairs. Sequence analysis indicated that the V3 loop nucleotide and protein sequences aligned more closely with HIVANT70 compared to other Group O sequences. The amino acid sequences at the octameric tip of the V3 loop were RIGPLAWY, RIGPMAWY, or GLGPLAVY. The tetrameric tip GPLA is represented only once in the published 1994 HIV database (Los Alamos) but was present in 2 of 4 of EG samples. The immuno-dominant region (IDR) sequences derived from EG sera were unique in that none of the sequences were completely homologous to other HIV-1 group O variants. Further, the HIV-1 group O sequence variation could be correlated with differential serologic reactivity using IDR peptides. Compared to HIV-1, the sequence information on HIV-2 isolates is relatively limited, though the HIV-2 isolates also show genetic variation similar to HIV-1. To further establish a correlation between the genetic diversity and serologic detection of HIV-2, plasma samples from Western Africa were evaluated. Eight samples were selected based on weak serologic reactivity to env proteins. PCR amplification and sequence analysis of the gag, env V3 loop, and env IDR regions indicated that the samples could be classified as subtypes A (4 samples), B (3 samples) and D (1 sample). Across the subtypes, there was conservation in the IDR region of the sequence WGCAFRQVCHT. This region is absolutely conserved among the majority of currently known HIV-2 and related SIV viruses (1994 HIV database). One subtype B sample had a unique sequence immediately adjacent to the IDR, however, this did not change the serologic detection using a HIV-2 IDR specific monoclonal antibody.

Leiomyosarcoma occurring in the ligamentum teres of the liver: a case report and a review of seven reported cases

We treated a 49-year-old male with leiomyosarcoma of the ligamentum teres of the liver. Preoperative hepatic imagings revealed a mass in the median segment of the liver. The patient underwent surgery, and the mass, measuring 6x5cm in size, was pathologically diagnosed as leiomyosarcoma arising from the ligamentum teres. To our knowledge, only eight cases of this rare tumor have been reported to date in the English literature.

Mechanistic studies on metabolic chiral inversion of 4-(4-methylphenyl)-2-methylthiomethyl-4-oxobutanoic acid (KE-748), an active metabolite of the new anti-rheumatic agent 2-acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanoic acid (KE-298), in rats

The chiral inversion properties of 4-(4-methylphenyl)-2-methylthiomethyl-4-oxobutanoic acid (KE-748), an active metabolite of 2-acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanoic acid (KE-298), were compared with those of ibuprofen in rats. After administration of R(-)-[2 alpha-2H]KE-748, S(+)-KE-748 was present in the rat plasma, and the deuterium atoms of the S(+)-enantiomer were almost all replaced by hydrogen atoms. After administration of S(+)-[2 alpha-2H]KE-748, the deuterium content of S(+)-KE-748 in the plasma remained intact. In the in vitro study, using a cell-free system and rat liver homogenates, the chiral inversion of ibuprofen was apparent when both CoA and ATP were present; however, KE-748 was not inverted. In the study on isolated rat hepatocytes, the unidirectional chiral inversion from R(-)-to S(+)-enantiomer was observed for both ibuprofen and KE-748. When R(-)-ibuprofen was incubated with medium and long chain fatty acids (carbon chain length C6 to C16), using isolated hepatocytes, the chiral inversion decreased significantly. On the other hand, when R(-)-KE-748 was incubated with short and medium chain fatty acids (carbon chain length C3 to C8), chiral inversion was inhibited markedly. To induce hepatic microsomal long chain fatty acid CoA ligase, rats were treated with clofibric acid (CF rats). In both in vitro and in vivo experiments on CF rats, chiral inversion from R(-)-to S(+)-ibuprofen was enhanced significantly compared with that in controls, whereas the enhancement was not observed in the case of R(-)-KE-748. There was no influence of benzoic acid, a typical substrate on medium chain fatty acid CoA ligase in the mitochondrial matrix, on chiral inversion of R(-)-ibuprofen, using, isolated hepatocytes. In contrast, the chiral inversion from R(-)-to S(+)-KE-748 was strongly inhibited in the presence of benzoic acid. These results indicate that chiral inversion of R(-)-KE-748 may proceed via formation of the CoA-thioester intermediate with loss of the 2 alpha-methine proton, in a manner similar to that seem with R(-)-ibuprofen. However, the enzymes needed to form CoA-thioester of R(-)-KE-748 differ from those for R(-)-ibuprofen.

Electron microscopic study of human immunodeficiency virus type 1 (HIV-1) core structure: two RNA strands in the core of mature and budding particles

The basic structure of human immunodeficiency virus type 1 (HIV-1) has been investigated morphologically; however, the internal structure of HIV-1 core is not well understood. We studied the internal structures by transmission electron microscopy. We modified the method for electron staining of ultrathin sections and processed electron microscopic photographs using a computer. We confirmed that a mature HIV-1 particle had two copies of RNA strands in a cone-shaped core. These two RNA strands formed a coiling structure and interwound each other, and were already present in the late budding stage.