Total synthesis of brevetoxin A

Brevetoxin A is the most potent neurotoxin secreted by Gymnodinium breve Davis, a marine organism often associated with harmful algal blooms known as 'red tides'. The compound, whose mechanism of action involves binding to and opening of sodium channels, is sufficiently toxic to kill fish at concentrations of nanograms per ml and, after accumulation in filter-feeding shellfish, to poison human consumers. The precise pathway by which nature constructs brevetoxin A is at present unknown, but strategies for its total synthesis have been contemplated for some time. The synthetic challenge posed by brevetoxin A reflects the high complexity of its molecular structure: 10 oxygen atoms and a chain of 44 carbon atoms are woven into a polycyclic macromolecule that includes 10 rings (containing between 5 and 9 atoms) and 22 stereogenic centres. Particularly challenging are the 7-, 8- and 9-membered rings which allow the molecule to undergo slow conformational changes and force a 90 degrees twist at one of its rings. Here we describe the successful incorporation of methods that were specifically developed for the construction of these rings into an overall strategy for the total synthesis of brevetoxin A in its naturally occurring form. The convergent synthesis reported here renders this scarce neurotoxin synthetically available and, more importantly, allows the design and synthesis of analogues for further biochemical studies.

[Weight gain pattern in normal pregnant women]

OBJECTIVE

The purpose of this study was to determine the maternal weight gain pattern of normal pregnant women.

METHODS

One thousand five hundred and sixty-two (1,562) women, with 11,059 records, received prenatal care and had their babies delivered at the Second Hospital of West China University of Medical Sciences during the period of Jan. 1-Dec. 31, 1995. All the women without complications and with their babies weighted between 2,500-3,999 g were included, and data was analyzed.

RESULTS

The average age was 26.49 +/- 3.02 and height 158.69 +/- 4.85 cm. The women were divided into three categories according to their prepregnant body mass index (BMI): underweight (< 16.75), normal weight (16.75-23.71) and overweight (> 23.71). The BMIs of each categories increased as gestational week approached to the term, with total BMI increase as 8.07, 5.37, 3.82 for underweight, normal weight and overweight, respectively.

CONCLUSION

BMI, calculated with weight and height, is more accurate to assess maternal weight gain than weight alone do, and above results and accompanied charts could be used to monitor maternal weight gain as a reference.

[Molecular analysis of HLA-DR beta polymorphism in Han nationality patients with rheumatoid arthritis]

OBJECTIVE

To analyze the molecular basis for HLA-DR associations with rheumatoid arthritis(RA) in the han nationality of Chinese population.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques were used to dertermine DRB1 alleles in 35 unrelated patients with RA and 100 healthy controls from the Han nationality.

RESULTS

The frequency of DR4(DRB1 * 04) was 51.4% in RA patients and 24.0% in the healthy controls(P < 0.01, RR = 3.3). There was a significant increase in the presence of the amino acid sequences QKRAA or QRRAA both in the RA patients overall compared with the healthy group(65.7% vs 30.0%, P < 0.001) and in DR4+ RA patients compared with DR4+ healthy individuals(100% vs 75.0%, P < 0.05). Substitution of residues in QKRAA, V85 and G86 appeared to correlate with relative risk for RA, among the subjects having 0-1 amino acid substitution, RA occurred in 48.8%, whereas in subjects with 2-3 amino acid changes, RA was present in only 16.7%.

CONCLUSION

These results suggest that DR4 is strongly associated with RA in the Han nationality, and the dominant effect that determines susceptibility to RA is associated with QKRAA or QRRAA as well as V85 and G86.

Immunohistochemical study of Fas antigen expression in synovial tissues from patients with rheumatoid arthritis

OBJECTIVE

To investigate the location and expression of Fas (Apo-1, CD-95) antigen in synovial tissue from rheumatoid arthritis (RA).

METHODS

Immunohistochemical technique was used to identify the location and expression of Fas antigen in synovial tissues from 27 RA, 11 osteoarthritis (OA), 7 ankloysing spondylitis (AS), 3 pigmented villo-hyperplastic synovitis, 1 juvenile rheumatoid (JRA) patients and 5 "normal" control subjects.

RESULTS

Fas was strongly expressed by synoviocytes and infiltrated lymphocytes in approximately two-thirds of RA patients (16/27). However, only weak expression occurred on lymphocytes in 3 of 11 OA, 1 of 7 AS patients and 1 of 5 "normal" subjects. The stain-positive substance in the forms of rings, granules, or dust was deposited on the cell membrane and in cytoplasm.

CONCLUSION

The expression of Fas may be involved in the mechanism of synovium proliferation and abnormal activation of local lymphocytes in RA.

[In vitro study on arsenic trioxide-inducing apoptosis in primary acute promyelocytic leukemie cells]

OBJECTIVE

To illustrate mechanisms of arsenic trioxide(As2O3) in the treatment of acute promyelocytic leukemia (APL).

METHODS

Cell-DNA content distribution, CD11b and CD33 antigens and nitroblue tetrazolium (NBT) reduction were evaluated in fresh APL cells from six APL patients treated in vitro with As2O3.

RESULTS

As2O3 had double effects on the cells inducing apoptosis and inducing partial differentiation at higher and at lower drug concentrations, respectively. As2O3 (0.1 approximately 2.0 micromol/L) could rapidly modulate and degrade APL-specific marker molecule PML-RARalpha protein, which could play an important role in the effects of As2O3 on APL cells.

CONCLUSION

As2O3 had double effects (induction of apoptosis and partial differentiation) on APL cells through the modulation and degradation of PML-RARalpha proteins.

Specific adaptation of gastric emptying to diets with differing protein content in the rat: is endogenous cholecystokinin implicated?

BACKGROUND

Recent studies indicate that gastric emptying may be influenced by patterns of previous nutrient intake. Endogenous cholecystokinin (CCK), whose synthesis and release can be affected by dietary intake, has a major role in the regulation of gastric emptying.

AIMS

To evaluate the influence of diets with differing protein content on gastric emptying of differing liquid test meals and plasma CCK levels in the rat and to check whether the inhibitory effect of exogenous CCK on gastric emptying is modified after long term intake of diets with differing protein content.

METHODS

Rats were fed for three weeks with high protein, medium protein (regular), or low protein diet. On day 22 gastric emptying of a peptone meal was studied. In addition, basal and postprandial CCK levels after the different dietary regimens were measured by bioassay. The time course of dietary adaptation was studied and its specificity assessed through the use of different (peptone, glucose, and methylcellulose) test meals. The effect of exogenous CCK-8 on gastric emptying was studied at the end of the adaptation period (three weeks).

RESULTS

Feeding the animals with a high protein diet for three weeks resulted in a significant (p < 0.05) acceleration (by 21.2 (8.2)%) of gastric emptying while feeding with a low protein diet was followed by a significant (p < 0.05) delay (by 24.0 (6.2)%) in the emptying rate. When the time course of the effect of dietary adaptation on gastric emptying was studied, it appeared that at least two weeks are required for dietary protein to be effective. The regulatory effect of dietary protein on gastric emptying proved to be dependent on meal composition. Only the emptying rate of a protein containing meal (40% peptone) was significantly modified by previous dietary intake. No significant (p > 0.05) changes were observed with glucose and methylcellulose meals whose emptying rates were similar in rats receiving a high protein or low protein diet. A peptone meal strongly and significantly (p < 0.05) increased plasma CCK levels in rats fed a medium protein (regular) diet. Results were similar in rats receiving a low protein diet (p < 0.05) but not in rats on a high protein diet (p > 0.05). As a consequence, postprandial plasma levels of CCK in rats fed with a medium or low protein diet were significantly (p < 0.05) higher than those in rats receiving a high protein diet. In rats on high and low protein diets, dose response curves to CCK-8 were virtually identical, suggesting that dietary protein intake has no influence on the effect of exogenous CCK.

CONCLUSIONS

These results clearly show that gastric emptying of a protein containing meal can be modified by previous dietary protein intake. This effect, which is time dependent and meal specific, may be related to changes in endogenous CCK release which will affect emptying rate. While the exact mechanisms underlying this adaptive response need to be studied and clarified further, these results emphasise the importance of dietary history in the evaluation and interpretation of gastric emptying data.

Phosphorylation of the Kv2.1 K+ channel alters voltage-dependent activation

The voltage-gated delayed-rectifier-type K+ channel Kv2.1 is expressed in high-density clusters on the soma and proximal dendrites of mammalian central neurons; thus, dynamic regulation of Kv2.1 would be predicted to have an impact on dendritic excitability. Rat brain Kv2.1 polypeptides are phosphorylated extensively, leading to a dramatically increased molecular mass on sodium dodecyl sulfate gels. Phosphoamino acid analysis of Kv2.1 expressed in transfected cells and labeled in vivo with 32P shows that phosphorylation was restricted to serine residues and that a truncation mutant, DeltaC318, which lacks the last 318 amino acids in the cytoplasmic carboxyl terminus, was phosphorylated to a much lesser degree than was wild-type Kv2.1. Whole-cell patch-clamp studies showed that the voltage-dependence of activation of DeltaC318 was shifted to more negative membrane potentials than Kv2.1 without differences in macroscopic kinetics; however, the differences in the voltage-dependence of activation between Kv2.1 and DeltaC318 were eliminated by in vivo intracellular application of alkaline phosphatase, suggesting that these differences were due to differential phosphorylation. Similar analyses of other truncation and point mutants indicated that the phosphorylation sites responsible for the observed differences in voltage-dependent activation lie between amino acids 667 and 853 near the distal end of the Kv2.1 carboxyl terminus. Together, these parallel biochemical and electrophysiological results provide direct evidence that the voltage-dependent activation of the delayed-rectifier K+ channel Kv2. 1 can be modulated by direct phosphorylation of the channel protein; such modulation of Kv2.1 could dynamically regulate dendritic excitability.

Isolation of new bioactive annonaceous acetogenins from Rollinia mucosa guided by liquid chromatography/mass spectrometry

Reversed-phase high-performance liquid chromatography (RP-HPLC) fractionation, monitored by liquid chromatography/electrospray mass spectrometry (LC/ESI-MS), led to the isolation of two new bioactive annonaceous acetogenins, rollidecin C (1) and rollidecin D (2), from the bioactive aqueous methanol fraction of the leaves of Rollinia mucosa (Annonaceae). The structures were confirmed by analyses of the 1H and 13C NMR data. In addition, a known adjacent bis-tetrahydrofuran (THF) acetogenin, desacetyluvaricin (3), was isolated from this plant for the first time utilizing the LC/ESI-MS monitoring approach. Compound 1 exhibited selective cytotoxicity toward the colon tumor cell line (HT-29), while 2 showed only borderline cytotoxicity in a panel of six human tumor cell lines.

[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.

The FHIT gene is alternatively spliced in normal kidney and renal cell carcinoma

FHIT (Fragile Histidine Triad), a putative tumor suppressor gene, was cloned from fetal brain and colon cDNA libraries. Portions of this gene are deleted in esophageal, colon, lung and breast tumors, but this gene has not been found altered in sporadic renal cell carcinomas. We report here an alternatively spliced form of this gene cloned from a kidney cDNA library. This cDNA is 1189 bp in length, and contains an additional 94 bp exon, designated exon 2a (E2a). This novel sequence is located between exon 2 and exon 3 of the FHIT gene's untranslated region and exon 2a is present in all normal kidney tissues and cell lines. Analyses performed on sporadic renal cell carcinoma (RCC) tissues and cell lines, show consistent loss of exon 8 of the FHIT cDNA in almost 60% of the cases. Interestingly, in a familial, as well as, in a metastatic RCC, derived from a patient with the sporadic form, exon 2a and exon 3 are also deleted. Northern analyses with the exon 2a of the familial and the metastatic RCC demonstrates concurrent loss of expression of a 4.4 kb transcript with the loss of the E2a sequence, suggesting that exon 2a of the FHIT gene may play an important role in the oncogenesis of renal cell carcinoma.

[Double effects of arsenic trioxide (As2O3) on acute promyelocytic leukemic cell line]

OBJECTIVE

To investigate the effects of a wide range of concentrations of As2O3 on NB4 cells.

METHODS

Cell morphology, cell-DNA content distribution, CD11b and CD33 antigens and nitroblue tetrazolium (NBT) reductions were evaluated in an APL cell line NB4 cells with or without As2O3 treatment. In addition, immunofluorescent analysis for APL marker molecule PML-RAR alpha was also performed.

RESULTS

1-2 mumol/L of As2O3 treated NB4 cells presented morphologically some features of apoptotic cells such as intact cell membrane, chromatin condensation and nuclear fragmentation. Sub-G1 cells, whose percentage presents concentration and time-dependency, were observed by flow cytometer. Otherwise, NB4 cells with the treatment of As2O3 at 0.1-0.25 mumol/L for a long time (10 days) have differentiation-related morphology, and their differentiation antigens CD11b and CD33 were also modulated to some extent. In addition, 0.1-2 mumol/L of As2O3 could rapidly and effectively modulate and degradate PML/PML-RAR alpha proteins.

CONCLUSION

As2O3 had double effects (induction of apoptosis and imcomplete differentiation) on NB4 cells, which could associate with rapid modulation and degradation of PML/PML-RAR alpha proteins.

Chromosomal abnormality inv(3)(q21q26) associated with multilineage hematopoietic progenitor cells in hematopoietic malignancies

We have identified ten patients with acute myeloid leukemia (AML) and one patient with chronic myeloid leukemia with megakaryocytic crisis who displayed an inv(3)(q21q26). Seven of them had an additional monosomy 7. Most of them had a myelodysplastic syndrome (MDS) preceding AML, normal or increased platelet counts, increased number of megakaryocyte, megakaryocytic dysplasia, and erythroid dysplasia. There was a high incidence of resistance to induction chemotherapy, short remission time, and early relapse. Seven patients were immunologically analyzed. The main immunophenotypes were as follow: CD7+, CD34+, HLA-DR+, CD38+, CD13+, CD33+, CDw65+, CD2-, CD3-, CD4-, CD8-, CD19+, CD20-, CD11b-. Our results suggest that the leukemia with inv(3)(q21q26) represents a new cytogenetic-clinicopathologic subtype, characterized by 1) abnormal megakaryopoiesis and multiple hematopoietic lineage involvement; 2) an antecedent MDS; 3) poor response to conventional chemotherapy; and 4) expression of CD7, CD34, CD38, HLA-DR, CD13, and CD33 antigens. We propose that the malignant transformation in patients with inv(3)(q21q26) occurs in an early stem cell prior to lineage commitment.

Reinterpretation of G-banded complex karyotypes by fluorescence in situ hybridization with chromosome-specific DNA painting probes and alpha-satellite centromere-specific DNA probes in malignant hematological disorders

In this study, we have performed fluorescence in situ hybridization (FISH) with chromosome-specific DNA painting probes 1, 2, 3, 4, 6, 8, and 12 and centromere-specific DNA probes 7,10,12,17,18, and X after G-banding on the same metaphase spreads from four patients with malignant hematological disorders to more precisely interpret their complex karyotypes. The findings demonstrated that the application of combined G-banding and FISH can more accurately explain complex karyotypes of hematological malignancies. FISH can detect not only the origin of marker chromosomes, but also the complex rearrangements that cannot be identified by routine banding techniques. This approach is very important to complement the cytogenetic analysis of malignant disorders and to evaluate the role of chromosome change in the development, progression, and prognosis of tumors.

Bioactive annonaceous acetogenins from Rollinia mucosa

Two new bioactive Annonaceous acetogenins, rollitacin (1) and rollinacin (2), along with one known acetogenin, javoricin, were isolated from the ethanolic extract of the leaves of Rollinia mucosa. Compounds 1 and 2 exhibited selective inhibitory effects among six human solid tumour cell lines. The structural elucidations of 1 and 2 were achieved by various spectroscopic analyses and chemical derivatizations.

Konishiol, a new sesquiterpene, and bioactive components from Cunninghamia konishii

Three sesquiterpenes, konishiol (1), cadalenol (2), 3-cedranol (3), one diterpene, manool (4), and one lignan, (+)-tsugacetal (5), have been isolated, for the first time, from the whole plant of Cunninghamia konishii by using bioactivity-directed fractionation. Compound 1 is new to the literature, and its chemical structure was determined by various spectroscopic analyses including EIMS, HREIMS, NOE, NOESY, and by preparing its di-acetyl derivative (1a). Compounds 2-5 showed moderate to weak bioactivities in brine shrimp (BST) and mosquito larvae (YFM) bioassays as well as cytotoxicities against three human solid tumor cell lines.

[DNA typing for HLA-DR and HLA-DQ alleles in Chinese patients with rheumatoid arthritis]

We analysed the associations of DR and DQ alleles with rheumatoid arthritis (RA) in Han nationality of China. PCR-RFLP technique was used to determine DRB1, DQA1 and DQB1 alleles in 35 unrelated patients with RA and 100 healthy controls from the Hans. The frequency of DR4 was 51.4% in RA patients and 24.0% in the healthy controls (P < 0.01, RR = 3.30). Subtyping of DR4 revealed no differences in the relative distributions of the DR4 alleles between the RA group and the controls, which both were predominated by DRB1 * 0405 allele, but there was a significant increase in the absolute frequency of DRB1 * 0405 in RA patients compared with the healthy controls (31.4% vs 12.0%, P < 0.01). DQ4 (DQB1 * 04) was also increased both in the RA patients compared with the healthy controls (37.1% vs 10.0%, P < 0.001) and in DR4+ RA patients compared with DR4+ healthy ones (72.2% vs 41.6%, P = 0.0376). Further analysis showed that the haplotype DR4-DQ4 was associated with RA (RR = 5.17, P < 0.001), and that the DR4(+)-DQ4+ patients had more severe disease than the DR4- patients. These results suggest that DR4, mainly the DRB1 * 0405, is associated with RA in Han nationality, and DQ4 may play a role in DR4 conferring susceptibility to RA. The DR4-DQ4 haplotype could be taken as a predictive marker for disease severity.

Screening for Annonaceous acetogenins in bioactive plant extracts by liquid chromatography/mass spectrometry

The Annonaceous acetogenins are amenable to analysis by liquid chromatography/mass spectrometry (LC/MS) using the electrospray positive-ion mode. Under conditions of atmospheric pressure in-source collision-induced dissociation (APICID), the acetogenins reproducibly provided characteristic ion patterns and fragment ions. Accordingly, the presence of these biologically interesting acetogenins and other derivatives in plant extracts and chromatographic fractions can be readily detected by analyzing selected ion chromatograms. LC/MS screening of a bioactive crude methanol-soluble fraction of Rollinia mucosa detected the presence of some 40 known acetogenins in this plant extract, in addition to four new acetogenins of diverse structure. This rapid and relatively uncomplicated selected ionization procedure should also prove suitable for the screening of many other structural families of natural products.

Additional bioactive annonaceous acetogenins from Asimina triloba (Annonaceae)

Trilobalicin (1), a new nonadjacent bis-THF ring annonaceous acetogenin, 2,4-cis- (2) and 2,4-trans-trilobacinone (3), the ketolactones of trilobacin, an adjacent bis-THF ring acetogenin, were isolated from the stem bark of Asimina triloba (L.) Dunal (Annonaceae). Their structures were established based on chemical and spectral evidence. The relative stereochemistry of 1 was determined as trans/threo/threo/trans/erythro from C-10 to C-22 by comparisons of NMR data with those of model compounds. Compound 1 is the first example of a nonadjacent bis-THF acetogenin being isolated from the title species and represents a new type of these compounds. Bioactivities of these new structures against brine shrimp larvae and six human solid tumor cell lines were determined, and cytotoxic selectivities were shown for the lung (A-549) and breast (MCF-7) cell lines with up to a million times the potency of adriamycin.

[Comparison between magnetic resonance imaging and CT in detection and localization of non-magnetic intraocular foreign bodies]

OBJECTIVE

To approach the characteristics of magnetic resonance imaging (MRI) and CT in detection and localization of intraocular foreign bodies.

METHODS

Detection and localization of 28 cases (42 foreign bodies) of non-magnetic intraocular foreign body were compared in MRI and CT with criteria of operative results.

RESULTS

The positive rates of MRI and CT in detection of 42 non-magnetic intraocular foreign bodies were respectively 90.5% and 95.2% (chi 2 test: P > 0.5). The positive rates of MRI and CT in localization were respectively 89.5% and 60.0% (chi 2 test: P < 0.05).

CONCLUSION

MRI could be used in detection and localization of non-magnetic intraocular foreign bodies with high positive rates in detection and superior to CT in demonstrating non-magnetic intraocular foreign bodies with low density and the relationship between foreign bodies and intraocular tissues. MRI was not as believable as CT in detection of foreign bodies in eye wall and not an appropriate modality in examinations of magnetic intraocular foreign body.

Bioactive compounds from Taiwania cryptomerioides

Two new sesquiterpenes, 10 alpha-hydroxyamorphan-4-en-3-one (1) and 4 alpha-methylcadinane-4 alpha-methyl-1 alpha,2 alpha,10 alpha-triol (2), together with four known compounds, sesquiterpenes 10 alpha-hydroxycadinan-4-en-3-one (3) and alpha-cadinol (4), diterpene ferruginol and lignan helioxanthin, were isolated from the whole plant of Taiwania cryptomerioides under bioassay-guided fractionations. The structures of 1 and 2 were elucidated mainly by the NMR spectroscopic analyses. Bioactivities of the isolated compounds against brine shrimp, yellow fever mosquito larvae, and human tumor cells are reported; compound 4 was the most bioactive, showing selectivity for the human colon tumor cell line (HT-29).

[Studies on distribution patterns of modulator CGRP in different motoneuron pools in rats]

Using retrograde labelling combined with calcitonin gene-related peptide (CGRP) immunocytochemistry technique, distribution patterns of the content of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) were studied in two different motoneuron (Mn) pools supplying soleus (SOL, slow-twitch muscle) and extensor digitorium longus (EDL, fast-twitch muscle) of hindlimbs in rats during development. The Mn pools were identified with a novel retrograde tracer, choleragen B subunit (CB) coupled with colloidal gold (CB-Au, 5 nm particle, prepared by ourselves), which was injected into EDL or SOL. After the silver intensification for visualizing colloidal gold particles, CGRP immunocytochemistry were processed. The CB-Au retrogradely identified Mns in each Mn pool were counted and CGRP-LI intensity of Mns was evaluated as strong, moderate, weak and negative. The double labelling revealed different distribution patterns of CGRP-LI content between SOL and EDL Mn pools during development. Comparing the level of CGRP expression between the two Mn pools, SOL Mn pool had a higher ratio of neurons lacking CGRP-LI/weak CGRP LI and a lower proportion of strongly CGRP-LI labelled ones. These results suggest that the difference in content of CGRP-LI in Mns is related to the type of muscular motor activity.

Three new adjacent bis-tetrahydrofuran acetogenins with four hydroxyl groups from Asimina triloba

Three new adjacent bis-tetrahydrofuran ring Annonaceous acetogenins with four hydroxy groups, bullatetrocin (1), 10-hydroxyasimicin (2), and 10-hydroxytrilobacin (3), were isolated by activity-directed fractionation from the stem bark of Asimina triloba. Their structures were established on the basis of chemical and spectral evidence. The absolute stereochemistry at the C-10 hydroxy position was determined by converting 2 and 3 to their ketolactone isomers, 2,4-cis/trans 10-hydroxyasimicinones and 2,4-cis/trans 10-hydroxytrilobacinones, respectively. The bioactivities of the new compounds against brine shrimp larvae and six human solid-tumor cell lines are reported, and structure-activity relationships between trihydroxylated and tetrahydroxylated acetogenins are discussed. In addition to 1-3, gigantetrocin A, 2,4-cis/trans-gigantetrocin A-ones, annonacin, and annonacin A were also isolated for the first time from this species.

Chlorinated annonaceous acetogenins and their bioactivities

4(S)-Chloro-4-deoxygigantetrocin A and 4(S), 18-dichloro-4,18-dideoxyasimilobin were obtained by treating gigantetrocin A with triphenylphosphine and CCl4. The structures were determined by spectroscopic methods. The chlorinated compounds show decreased bioactivities in the brine shrimp lethality test and against human tumor cell lines.

cis-gigantrionenin and 4-acetyl gigantetrocin A, two new bioactive annonaceous acetogenins from Goniothalamus giganteus, and the stereochemistries of acetogenin 1,2,5-triols

Using activity-directed fractionation, two new bioactive acetogenins, cis-gigantrionenin (1) and 4-acetyl gigantetrocin A (2), have been isolated from the bark of Goniothalamus giganteus (Annonaceae). Compound 1 has a cis-mono-THF ring with one flanking hydroxyl and possesses a cis-double bond at C-21/22 of the aliphatic chain; it represents only the second example of the cis-mono-THF ring annonaceous acetogenins having one flanking hydroxyl. Compound 2 has a trans-mono-THF ring with one flanking hydroxyl, but it possesses a mono-acetyl group at the 4-OH position; it represents only the second natural example of the acetylated annonaceous acetogenins; the first acetogenin reported, uvaricin, was mono-acetylated at the 24-OH. The stereochemistries of 1 and 2 were determined by the advanced Mosher ester method. In addition, the absolute stereochemistries of gigantriocin (3), gigantrionenin (4), and giganenin (5) were determined by the advanced Mosher ester method and by circular dichroism (CD). The stereochemistries of the 7,8-diols in murihexocins A (6) and B (7) were determined to have the S,S-configurations, respectively.

Applying Mosher's method to acetogenins bearing vicinal diols. The absolute configurations of muricatetrocin C and rollidecins A and B, new bioactive acetogenins from Rollinia mucosa

Muricatetrocin C (1), rollidecin A (2), and rollidecin B (3), three new bioactive annonaceous acetogenins bearing vicinal diols, were isolated from the leaves of Rollinia mucosa (Annonaceae) using activity-directed fractionation. The total structural elucidations of 1-3, including the absolute stereochemistries of the vicinal diols, were achieved by analyzing their per-Mosher ester derivatives. All three compounds showed potent and selective inhibitory effects against several human cancer cell lines.

Rollinecins A and B: two new bioactive annonaceous acetogenins from Rollinia mucosa

Two new mono-THF ring acetogenins, rollinecins A (1) and B (2), were isolated from the partitioned ethanolic extracts of the leaves of Rollinia mucosa (Annonaceae) by activity-directed fractionation. 1 and 2 are epimeric at the C-14 carbinol stereocenter. Their absolute stereochemical structures were solved by preparing their respective per-Mosher ester derivatives. 1 and 2 showed equivalent and selective in vitro activities against several human solid tumor cell lines.

Isolation of a new clathrin heavy chain gene with muscle-specific expression from the region commonly deleted in velo-cardio-facial syndrome

Velo-cardio-facial syndrome (VCFS) and DiGeorge syndrome (DGS) are developmental disorders characterized by a spectrum of phenotypes including velopharyngeal insufficiency, conotruncal heart defects and facial dysmorphology among others. Eighty to eighty-five percent of VCFS/DGS patients are hemizygous for a portion of chromosome 22. It is likely that the genes encoded by this region play a role in the etiology of the phenotypes associated with the disorders. Using a cDNA selection protocol, we isolated a novel clathrin heavy chain cDNA (CLTD) from the VCFS/DGS minimally deleted interval. The cDNA encodes a protein of 1638 amino acids. CLTD shares significant homology, but is not identical to the ubiquitously expressed clathrin heavy chain gene. The CLTD gene also shows a unique pattern of expression, having its maximal level of expression in skeletal muscle. Velopharyngeal insufficiency and muscle weakness are common features of VCFS patients. Based on the location and expression pattern of CLTD, we suggest hemizygosity at this locus may play a role in the etiology of one of the VCFS-associated phenotypes.

Longimicins A-D: novel bioactive acetogenins from Asimina longifolia (annonaceae) and structure-activity relationships of asimicin type of annonaceous acetogenins

Bioactivity-directed fractionation of the ethanol extract of Asimina longifolia led to the isolation of four novel bioactive annonaceous acetogenins: longimicins A-D (1-4). Compounds 1-4 represent the asimicin type of acetogenins; however, the locations of the adjacent bis-tetrahydrofuran (THF) ring moieties are shifted along the aliphatic chains compared to the known compounds of this type. They are the first examples among this type of acetogenins with the placements of the ring systems altered. Compounds 1-4 showed bioactivities in several bioassays, but they are less active than their structural isomers. Study of their structure-activity relationships (SAR) reveals that the position of the adjacent bis-THF ring moiety is essential for maximization of the bioactivities among these asimicin type annonaceous acetogenins.

[Preparation of huichun zhibao oral liquid (HZOL)]

The formulation, preparing method, quality standards, pharmacodynamic experinents and toxicological experiments of HZOL are described. The content of icariin, which is and effective component of epimedium herb as well as one of the main ingredients in HZOL, was successfully determined through HPLC, with an average recovery of 98.98% and RSD = 1.53%.

Beta subunits promote K+ channel surface expression through effects early in biosynthesis

Voltage-gated K+ channels are protein complexes composed of ion-conducting integral membrane alpha subunits and cytoplasmic beta subunits. Here, we show that, in transfected mammalian cells, the predominant beta subunit isoform in brain, Kv beta 2, associates with the Kv1.2 alpha subunit early in channel biosynthesis and that Kv beta 2 exerts multiple chaperone-like effects on associated Kv1.2 including promotion of cotranslational N-linked glycosylation of the nascent Kv1.2 polypeptide, increased stability of Kv beta 2/Kv1.2 complexes, and increased efficiency of cell surface expression of Kv1.2. Taken together, these results indicate that while some cytoplasmic K+ channel beta subunits affect the inactivation kinetics of alpha subunits, a more general, and perhaps more fundamental, role is to mediate the biosynthetic maturation and surface expression of voltage-gated K+ channel complexes. These findings provide a molecular basis for recent genetic studies indicating that beta subunits are key determinants of neuronal excitability.

Selective interaction of voltage-gated K+ channel beta-subunits with alpha-subunits

To begin to study the molecular bases that determine the selective interaction of the beta-subunits of voltage-gated K+ channels with alpha-subunits observed in situ, we have expressed these polypeptides in transfected mammalian cells. Analysis of the specificity of alpha/bet a-subunit interaction indicates that both the Kvbeta1 and Kvbeta2 beta-subunits display robust and selective interaction with the five members of the Shaker-related (Kv1) alpha-subunit subfamily tested. The interaction of these beta-subunits with Kv1 alpha-subunits does not require the beta-subunit N-terminal domains. Thus, the previously observed failure of N-terminal mutants of Kv beta1 to modulate inactivation kinetics of Kv1 family members is not simply due to a lack of subunit interaction. Interaction of these beta-subunits with members of two other subfamilies (Shab- and Shaw-related) could not be detected. Somewhat surprisingly, a member of the Shal-related subfamily was found to interact with beta-subunits; however, this interaction had biochemical characteristics distinct from the beta-subunit interaction with Kv1 family members. In all cases, Kvbeta1 and Kvbeta2 exhibited indistinguishable alpha-subunit selectivity. These studies point to a selective interaction between K+ channel alpha- and beta-subunits mediated through conserved domains in the respective subunits.

Bioactive ent-kaurene diterpenoids from Annona senegalensis

Activity-guided fractionation of the stem bark of Annona senegalensis gave four bioactive ent-kaurenoids (1-4). Compound 2 showed selective and significant cytotoxicity for MCF-7 (breast cancer) cells (ED50 1.0 microgram/mL), and 3 and 4 exhibited cytotoxic selectivity for PC-3 (prostate cancer) cells but with weaker potencies (ED50 17-18 micrograms/mL). The structure of the new compound, 3, was deduced from spectral evidence.

Selectively cytotoxic diterpenes from Euphorbia poisonii

Bioactivity-guided fractionation of the latex of Euphorbia poisonii Pax. (Euphorbiaceae) led to the isolation and characterization of a new tigliane diterpene, 12-deoxyphorbol 13-(9,10-methylene)undecanoate (3), together with five known diterpenes (1,2,4-6). When evaluated for cytotoxicity in a panel of six human solid tumor cell lines, the diterpene esters, 1-3, 5, and 6, were selectively cytotoxic for the human kidney carcinoma (A-498) cell line with potencies for 2 and 3 exceeding that of adriamycin by ten thousand times. Details of the isolations, structural analyses, and cytotoxic activities are described.

[Inhibitory action of Chinese compound prescription for reinforcing vital energy and invigorating blood circulation on cancer cell multiplication]

Experiments have proved that the Chinese compound prescription for reinforcing vital energy and invigorating blood circulation markedly helps to improve the morphology of cancer cell nucleolus and membrane surface microvillus, amend the composition of microtubulin and facilitate intercellular gap junctional communication. Cell cycle kinetics shows that the multiplication of cancer cells in human stomach is checked mainly at G2M stage.

Mapping of 29 YAC clones and identification of 3 YACs spanning the translocation t(3;8)(p14.2;q24.1) breakpoint at 8q24.1 in hereditary renal cell carcinoma

The constitutional balanced translocation (3;8)(p14.2:q24.1) has been described in a family in which a arge number of individuals developed renal cell carcinoma RCC) at an early age. The translocation event in which genes from the 3p14.2 and the 8q24.1 sites are brought in close proximity is considered a critical, initial step for the development and progression of RCC. Even though the 3p14.2 breakpoint region has been cloned, a gene has not yet been identified, which may be responsible for either the initiation or progression of hereditary RCC. As a crucial step toward cloning the 3;8 breakpoint at the 8q24.1 site, we have mapped a series of YACs which surround this region by fluorescence in situ hybridization (FISH). Three YACs have been identified that span the 8q24.1 breakpoint region. One of these YACs is approximately 180 kb in length, and has been used to initiate construction of a high resolution cosmid contig. Several cosmids have been isolated which have been positioned in relation to the 8q24.1 breakpoint region. In addition, we have positioned 26 other YACs in relation to the 3;8 translocation breakpoint. These results provide a basis for the isolation of genes surrounding 3;8 RCC translocation breakpoint region at 8q24.1.

3p21 is a recurrent treatment-related breakpoint in myelodysplastic syndrome and acute myeloid leukemia

In this study we report 11 cases with chromosome abnormalities involving 3p21. Nine cases were diagnosed as myelodysplastic syndrome (MDS), and two as acute myeloid leukemia (AML). Six of nine MDS cases were secondary to a primary malignant disease. In two patients, AML was secondary to breast cancer and polycythemia vera (PV). Seven of eleven patients had a history of intensive polychemotherapy and/or radiation therapy for 3.5 to 5 years. The mean interval from initial therapy to secondary disease was 13.2 years. Complex chromosomal aberrations were found in all 11 cases. Band 3p21 was involved in translocations in 9 patients and in deletions in 2 patients. A t(3;16)(p21;p13) was found in two cases. Additional abnormalities frequently included a -5, -7, as well as deletions or rearrangements of these 2 chromosomes. Data reported in this paper suggest that 3p21 is a recurrent treatment-related breakpoint in MDS and AML and is likely to contain a gene involved in the pathogenesis of this disease.

Reflux related symptoms in patients with normal oesophageal exposure to acid

Several studies, using pH monitoring with event markers, have identified patients with normal oesophageal exposure to acid despite an apparent relation between symptoms and reflux episodes. In this series of 771 consecutive patients referred for 24 hour oesophageal pH monitoring, a probability calculation was used to evaluate the relation between symptoms and reflux episodes. Oesophageal exposure to acid was normal in 462 of 771 recordings (59.9%); despite this, 70.8% (327 of 462) of these patients used at least once the event marker. In 96 patients (12.5% of total patients) with normal oesophageal exposure to acid, there was a statistically significant association between symptoms and reflux episodes. The symptom cluster of such patients was similar to that usually seen in patients with gastro-oesophageal reflux disease, but symptoms like belching, bloating, and nausea were common thus overlapping with the symptom pattern of functional dyspepsia. In these patients both the duration and the minimum pH of reflux episodes (either symptom related or asymptomatic) were significantly shorter and higher, respectively, when compared with those of patients with gastro-oesophageal reflux disease. These results are consistent with the idea that oesophageal hypersensitivity to acid is the underlying pathophysiological feature of this syndrome.

[Analysis of the multidrug resistance MDR1 gene expression in clinical leukemia with RT-PCR]

The method of reverse transcription coupled with polymerase chain reaction (RT-PCR) has been used to detect multidrug resistance gene MDR1 expression in 73 leukemia patients. Specificity of MDR1 PCR product was identified by a probe labelled with biotin. In this paper, beta 2M mRNA (a 120bp of PCR product) was selected as an internal control for semi-quantitative analysis of MDR1 mRNA (a 157bp of PCR product). Detection of MDR1 expression was positive in 31 of the 73 patients with leukemia. The percentage of MDR1+ and the value of MDR1/beta 2M in the relapsed acute leukemia and CML in blast crisis were 76.00% and 0.798 +/- 0.266, they were significantly higher than those in newly diagnosed acute leukemia (25.00% and 0.386 +/- 0.128) and complete remission leukemia (25.00% and 0.151 +/- 0.059), MDR1/beta 2M in newly diagnosed was significantly higher than that in complete remission. We found that MDR1 gene expression correlated well with response to chemotherapy in 53 cases of acute leukemia. The refractory rate in patients with MDR1+ was 75.00%, while it was 15.00% in MDR1- (P < 0.01). We thought that the determination of MDR1 expression level in acute leukemia could provide a valuble information for designing chemotherapeutic regimen in individual patient, and a high level of MDR1 expression correlated closely with drug resistance in clinical leukemia chemotherapy.

[Serum anti-subtypical Klebsiella pneumoniae antibodies in ankylosing spondylitis]

This study was performed in order to probe the possible pathogenesis of Klebsiella pneumoniae (KP) in ankylosing spondylitis (AS). 34 anti-KP antibody positive serum samples, including 26 patients with AS, 5 patients with rheumatoid arthritis (RA) and 2 healthy individuals, were selected to detect anti-subtypical KP antibodies by using an immunoblotting technique. The results showed that the number of antigenic bands to KP on nitrocellulose membrane was higher in AS patients than in RA patients and healthy individuals. Patients with AS had common antibodies response to KP components weight 64,600 (80.7%), 48,200 (61.5%) and 36,000 (65.4%), patients with RA and healthy individuals had anti-36,000 (75%) and anti-30,000 (50%) antibodies. Human anti-HLA-B27 serum and rabbit antisera against KP-derived synthetic peptide containing the hexapeptide sequence shared by HLA-B27 were able to cross react with 64,600 and 48,200 KP components. Our findings suggest that KP might play a role in the pathogenesis of AS by molecular mimicry between it and HLA-B27.

A Conducting Polymer Film Stronger Than Aluminum

Polythiophene (Pth) was electrochemically deposited onto stainless steel substrate from freshly distilled boron fluoride-ethyl ether containing 10 millimoles of thiophene per liter. The free-standing Pth film obtained at an applied potential of 1.3 volts (versus Ag/AgCl) had a conductivity of 48.7 siemens per centimeter. Its tensile strength (1200 to 1300 kilograms per square centimeter) was greater than that of aluminium (1000 to 1100 kilograms per square centimeter). This Pth film behaves like a metal sheet and can be easily cut into various structures with a knife or a pair of scissors.

[Surgical treatment of benign stenosis of the esophagus]

From Nov. 1972 to 1983 Oct., 88 patients with benign stenosis of the esophagus were operated on. The youngest patients was 18 months, and the oldest 63 years. From corrosive injury of esophagus to operation, the shortest period was 13 days and longest 10 years (mean 120 days). In 85 patients, transverse colon was used to replace the esophagus substernally. In 2 patients, reconstruction was done by gastric tube. One patient used transverse colon and part of descending colon. Preoperative gastrostomy was made in 5 patients. There was no operative mortality. One patient developed anastomotic stenosis postoperatively. He refused reoperation and died. The remaining patients survived with a normal life. For the reconstruction of esophagus, problems such as choice of grafts, time of operation, resection of scar or not, and place of anastomosis were discussed.

[Reconfirmation of golgiphobic dendrites of the motoneurons in rat spinal cord]

With CB-HRP method (injections into 5 muscles of anterior and posterior extremities) and Golgi technique, the corresponding sections of spinal cords were observed on same aged rats of the identical parent rats. Comparing the cell numbers of the lateral groups of anterior horns, the former (CB-HRP) revealed twice as many as the cell numbers of the latter (Golgi). As to the surface densities of the white matter dendrites (WMD) in the lateral funiculi from the neurons of the lateral groups of the anterior horns, the density revealed by injection of CB-HRP to the tibialis anterior is 2-9 times more than that in Golgi sections. All of WMD revealed in CB-HRP sections could extend into the peripheral portions of the lateral funiculi, and quite a few of them even form a subpial marginal plexus, that is one example of Golgiphobic dendrites (GBD). For labeled medial cell groups of the anterior horn with CB-HRP, their dendrites could reach to the ependymal layer of the central canal (another GBD). These two types of GBD were not present on the Golgi material. The significance of GBD was also discussed.

Properties of Kv2.1 K+ channels expressed in transfected mammalian cells

We have transiently expressed the rat Kv2.1 K+ channel polypeptide (pKv2.1) at high levels by transfection of mammalian COS-1 cells. Kv2.1-transfected cells express a molecular mass of 108 kDa pKv2.1, larger than the size of the core polypeptide (95 kDa) predicted from the deduced primary sequence and of pKv2.1 synthesized in cell free or Xenopus oocyte translation systems. The increased size of pKv2.1 in COS-1 cells is due to a posttranslational modification that occurs early (t1/2 = 5 min) in the biosynthetic transport through the endomembrane system, presumably while the protein resides in the endoplasmic reticulum. The increased size is entirely due to phosphorylation, based on in vivo 32P-labeling and sensitivity to alkaline phosphatase digestion. Immunofluorescent localization of pKv2.1 shows intense surface labeling; no intracellular pools of retained protein are apparent. Immunogold electron microscopy confirms that the expressed polypeptide is found on the cell surface in small clusters or patches of 10-15 gold particles. Cells expressing pKv2.1 exhibit large, voltage-dependent outward currents. The pharmacological properties of the expressed Kv2.1 currents are virtually indistinguishable from those described previously in Xenopus oocytes microinjected with Kv2.1 cRNA, but differences in voltage-dependent properties were observed. High level of expression of functional pKv2.1 in these cells points to the utility of this system for the rapid biochemical, cell biological and electrophysiological analysis of altered forms of pKv2.1, and other members of the K+ channel gene family.