[Transferrin subtyping of human semen, semen stain, vaginal fluid and mixed stain using isoelectric focusing and immunoblotting]

Transferrin (Tf) is an important genetic marker for personal identification in forensic science. We examined the subtypes in human semen, semen stain, vaginal fluid and mixed stain using isoelectric focusing and immunoblotting method(IEFIB). The results showed that, Tf subtypes of 8 semen and semen stain samples stored at room temperature for up to 32 weeks were the same as those in sera. Tf subtypes of 17 vaginal fluid and 4 mixed stain containing few semen were not detected. Tf Subtyping of 1 mixed stain containing enough semen was successful by using IEFIB. These results indicate that Tf is stable in semen stain. The Tf subtyping in semen stain and mixed stain containing enough semen can be carried out by using IEFIB method.

[The prognostic significance of regular bone marrow aspirations during induction chemotherapy in acute myeloid leukemia]

OBJECTIVE

To evaluate the prognostic significance of regular aspirations during induction chemotherapy in acute myeloid leukemia.

METHODS

Regular bone marrow aspirations were performed during the first course of induction chemotherapy in 96 cases of de novo AML.

RESULTS

Complete remission (CR) rate after the first course in patients with < or = 0.10 bone marrow blasts at the 7th day on chemotherapy was higher than that in patients with > 0.10 blasts (64.6% vs 40.0%, P < 0.05). Prolonged the chemotherapy course for a few more days in the latter group of patients increased CR rate from 25.0% to 50.0%. CR rate in patients with < or = 0.10 bone marrow blasts at the nadir of white blood cell count after chemotherapy was higher than that in patients with > 0.10 blasts (66.0% vs 25.8%, P < 0.005), and the refractory cases were significantly fewer in the former group of patients (7.5% vs 45.2%, P < 0.005).

CONCLUSION

Regular bone marrow aspirations during induction chemotherapy were helpful in predicting the prognosis and guiding the treatment in AML.

Lithium prevents ouabain-induced behavioral changes. Toward an animal model for manic depression

Both mania and bipolar depression have been associated with decrements in the activity of the sodium and potassium-activated adenosine triphosphatase (Na,K-ATPase) membrane pump. Although the role of this observation in the pathophysiology of bipolar illness is unclear, it has been proposed that this defect could be central to the pathogenesis of the illness. In an effort to test this hypothesis, the authors examined the efficacy of lithium pretreatment in attenuating behavioral changes secondary to acute administration of a single intracerebroventricular (i.c.v.) dose of the Na,K-ATPase-inhibiting compound, ouabain, in the Sprague-Dawley rat. Ouabain (10(-3)M) significantly decreased motor activity in automated activity monitors. Lithium pretreatment for 7 d totally prevented this effect. These preliminary data suggest that i.c.v. ouabain administration in the rat may prove to be a viable animal model for bipolar illness.

[Liver-protective activity of Aralia taibaiensis Z.Z. Wang et H.C. Zheng]

Compared with oleanolic acid and sodium chloride physiological solution, the water decoction of and the total saponin in root and cortex of Aralia taibaiensis were testified to have significant protective activity in experimental acute liver injury in mice induced by CCl4.

[Application of artificial humeral head in the treatment of tumor of upper end of humerus]

In order to restore the function of shoulder joint in patient with tumor of upper end of humerus, artificial humeral head replacement was performed. The materials included resinene, nylon-6 and large molecular polyethylene from 1978 to 1993, 14 patients were treated. The tumors involved in this group were giant cell tumor, synviosarcoma, bone cyst, osteochondroma, osteoblastoma, osteofibrosarcoma, osteosarcoma, chondrosarcoma, parosteosarcoma and malignant giant cell tumor. After resection of the tumor, the artificial prosthesis was implanted with bone cement. After 1 to 16 years follow-up, functions of the shoulder joint were reserved in 86% of the patients.

Thyroid hormone activates transcription from the promoter regions of some human nuclear-encoded genes of the oxidative phosphorylation system

Thyroid hormone (T3) modulates the mRNA levels for cytochrome c and the adenine nucleotide translocator-2 (ANT2) in adult rat liver. Here we show that T3 activates expression of a reporter gene driven from the human cytochrome c1 and ANT2 promoters transfected into human choriocarcinoma JEG3 cells. By contrast, the human F1-ATPase beta-subunit promoter responded marginally, thus providing a pattern of differential expression similar to that earlier observed in rats in vivo. T3-activation is dependent on co-expression of the thyroid hormone receptor (TR alpha1). Co-expression of both the TR and RXR receptors had no additional effect. Transient transfection of deletion constructs showed that T3 activation is retained by the proximal regions of the cytochrome c1 and ANT2 promoters, and, in the case of cytochrome c1, is lost upon removal of a fragment containing the transcription initiator ((nucleotides) (nt) + 1 to + 100). The promoter regions supporting T3-activation of the reporter genes appear to lack strong DNA binding sites for TR and retinoid X receptor (RXR).

p53-induced p21 controls DNA replication

The p21 protein, a regulator of cyclin-dependent kinases (CDKs), has been thought to be one of the key proteins to function in cell proliferation suppression upon DNA damage. In normal cells but not in many tumor cells, p21 forms a quaternary complex with a cyclin, a CDK and the proliferating cell nuclear antigen (PCNA), one of the DNA replication and repair factors, suggesting that this complex might play an important role in maintaining the integrity of the genome. Here, we have focused on the p21-PCNA interaction in the context of DNA replication or DNA repair, presenting the data from both in vitro and in vivo studies of the p21 function.

[Intracytoplasmic sperm injection in the management of male infertility and idiopathic fertilization failure]

OBJECTIVE

To demonstrate the efficacy of intracytoplasmic sperm injection (ICSI) in treatment male infertility and idiopathic fertilization failure.

METHODS

31 couples received intracytoplasmic sperm injections because of severe oligo-astheno-teratospermia or idiopathic infertility. Ovarian stimulation was achieved by conventional protocol. Transvaginal ultrasound-guided oocyte collections were done 36 hours after hCG injection. Only matured oocytes were selected for microinjection.

RESULTS

237 oocytes were treated by intracytoplasmic sperm injection; normal fertilization and cleavage occurred in 132 of 213 oocytes which were survived (62.0% normal fertilization rate). From 1995 to 1996, clinical pregnancies were achieved in 8 cases (25.8%). The first ICSI baby was delivered on October 3, 1996.

CONCLUSION

Intracytoplasmic sperm injection has improved the results of IVF-ET treatment in male and idiopathic infertility.

[Polymorphism and pologenetic affinities of genotype in pathogenic yeast]

The classification of pathogenic yeast, which is one of the most common reasons of opportunistic infection in human body, will be useful for the epidemiological survey and clinical works. The genotypic polymorphism of intergenus, interspecies and intraspecies in 48 isolates, including Candida, Cryptococcus, Torulopsis, Trichosporon, Saccaromyces had been administered carefully with patterns amplified by RAPD (Randomly amplified polymorphic DNA) in 53 primers. The pologenetic affinities had been evaluated by similarity coefficients obtained from these profiles. The results indicated that there are significant difference among intergenus, interspecies and intraspecies in Candida and related yeast. The similarity coefficients among Candida and Crytococcus, Trichosporon were maintained about 80%. The similarity coefficients among interspecies of Candida ranged from 82%-87%, and ones of intraspecies of different Candida species were more than 90%. The genotypic typing of species except C. guilliermondii seems to be related to morphological classification.

[Study on the effect of different disease courses on pre- and post-operative visual acuity in cases with congenital cataract]

OBJECTIVE

To study the effect of different disease courses on the visual acuity of congenital cataracts.

METHOD

876 cases with five kinds of human congenital cataract have been studied.

RESULTS

It has been found that the preoperative visual acuity (VA) is closely related to the length of disease course. The longer the course of disease, the worse the VA. When the disease courses were shorter than one year, the most serious reduction of preoperative VA was found in the patients with congenital total cataract. When the disease courses were within one to four years, the most remarkable reduction of VA was found in patients with congenital dense nuclear cataract (CDNC). When the disease courses were longer than four years, except the congenital anterior polar cataract, the VA in all the other four kinds of cataracts were decreased significantly. It is indicated that the postoperative VA highly depends on the preoperative VA. In the group with disease courses shorter than one year, this relationship is the most remarkable. Some kinds of congenital cataract showed accelerated changes in preoperative VA, especially in the CDNC.

CONCLUSION

It is suggested that the key point to get better visual function in cases with congenital cataract should be to discover and treat the patients as early as possible.

Residues of the Rho family GTPases Rho and Cdc42 that specify sensitivity to Dbl-like guanine nucleotide exchange factors

The Dbl-like guanine nucleotide exchange factor (GEF) Lbc oncoprotein specifically activates the small GTP-binding protein Rho in mammalian fibroblasts to induce transformation and actin stress fiber formation, whereas another Dbl-related molecule, Cdc24, stimulates guanine nucleotide exchange of the Rho family GTPase Cdc42 to elicit effects on both gene induction and actin-based cytoskeleton change in Saccharomyces cerevisiae. To understand the mechanism of these functional interactions, we have taken a biochemical approach to probe the sites on Rho and Cdc42 that are involved in coupling to their respective GEFs, the Lbc and Cdc24 proteins. Point mutations in the switch II region of the small G-proteins, many of which would affect the interaction with GEF in the case of Ras, or a mutation in the switch I region that was identified as a contact site between Rab3A and Rab GEF had little effect on RhoA or Cdc42Hs with regard to the ability to interact with Lbc or Cdc24, suggesting that there exists a unique mechanism of regulation of the Rho family proteins by their GEFs. Analysis of a panel of chimeras made between RhoA and Cdc42Hs, which all maintained the ability to respond to Dbl, their mutual GEF, and to GTPase-activating protein, revealed that at least two distinct sites in each of the GTPases are required for activation by the respective GEFs. Further site-directed mutagenesis studies showed that the conserved residue Tyr32 in the putative effector region of both GTPases (numbered by Cdc42Hs) is critical for binding of the GEFs and that specific recognition for Lbc or Cdc24 is achieved at least in part through residues Lys27 of Rho and Gln116 of Cdc42. Moreover, the loss of GEF responsiveness of a RhoA mutation (D76Q) was found to be caused by the impaired GEF catalysis, not by a change in the GEF binding affinity. Together, these results indicate that multiple sites of the Rho GTPases are involved in the regulation by GEFs, contributing to GEF binding or GEF catalysis, and raise the possibility that activation of each Rho family G-protein by a specific GEF may engage in a distinct mechanism.

Bee1, a yeast protein with homology to Wiscott-Aldrich syndrome protein, is critical for the assembly of cortical actin cytoskeleton

Yeast protein, Bee1, exhibits sequence homology to Wiskott-Aldrich syndrome protein (WASP), a human protein that may link signaling pathways to the actin cytoskeleton. Mutations in WASP are the primary cause of Wiskott-Aldrich syndrome, characterized by immuno-deficiencies and defects in blood cell morphogenesis. This report describes the characterization of Bee1 protein function in budding yeast. Disruption of BEE1 causes a striking change in the organization of actin filaments, resulting in defects in budding and cytokinesis. Rather than assemble into cortically associated patches, actin filaments in the buds of delta bee1 cells form aberrant bundles that do not contain most of the cortical cytoskeletal components. It is significant that delta bee1 is the only mutation reported so far that abolishes cortical actin patches in the bud. Bee1 protein is localized to actin patches and interacts with Sla1p, a Src homology 3 domain-containing protein previously implicated in actin assembly and function. Thus, Bee1 protein may be a crucial component of a cytoskeletal complex that controls the assembly and organization of actin filaments at the cell cortex.

Inhibition of p75 tumor necrosis factor receptor by antisense oligonucleotides increases hypoxic injury and beta-amyloid toxicity in human neuronal cell line

Recent evidence indicates that tumor necrosis factor-alpha (TNF-alpha) is up-regulated following brain injury and in neurodegenerative disorders such as stroke, multiple sclerosis, Parkinson's disease, and Alzheimer's disease. TNF-alpha elicits its biological effects through two distinct TNF receptor (TNFR) subtypes: p55 TNFR (TNFR1) and p75 TNFR (TNFR2). Studies have demonstrated that the p55 TNFR contributes to cell death, whereas the role of the p75 TNFR in neuronal viability is unclear. To better understand the role of p75 TNFR, we treated human neuronal SH-SY5Y cells with phosphorothioate-modified antisense oligonucleotides (ASO) for p75 TNFR and established that ASO inhibited p75 TNFR expression. Treatment of SH-SY5Y cells with ASO alone did not affect cell viability, whereas treatment with both ASO and human TNF-alpha significantly increased cell death relative to treatment with TNF-alpha alone. Moreover, addition of ASO significantly increased the level of cell injury observed following hypoxic conditions or exposure of beta-amyloid peptide. These results indicate that inhibition of p75 TNFR using ASO increases the vulnerability of neurotypic cells to insults and suggest that the p75 TNFR may not be required for normal neuronal cell viability but rather plays a protective role following injury.

[Study on the stunted culture of trees of Scaphium lychnophorum]

Taking these cultural practices, grafting by the ingraftment of side branch on the place of flowering with the dwarf stock, tip pruning on time to make branches growing and rational pruning etc can make the trees of Scaphium lychnbophorum dwafing effectively. The stunted trees are only high 3-5 m and their branches are only high about 1 m from the ground. Some of them first flower until five years after they are cultivated.

Structure of music may influence cognition

Classical music has been said to enhance cognition, which effect may be related to musical structure. 19 subjects who listened to highly structured music scored somewhat higher afterwards on cognitive performance than the 15 who listened to less structured music. Since this did not reach statistical significance, other as yet unidentified factors may also be involved.

The murine C'-terminally alternatively spliced form of p53 induces attenuated apoptosis in myeloid cells

The onset of p53-dependent apoptosis results from the accumulation of damaged DNA. Recently, it was shown that the C' terminus of the p53 protein plays a central role in sensing damaged DNA. In our present study, we examined the role of the C' terminus in the induction of apoptosis. A temperature-sensitive (ts) mutant of the alternatively spliced form of p53 (p53AS-ts) and the ts mutant of the regularly spliced form (p53RS-ts) were used to generate series of stable clones with increasing amounts of p53 protein. Apoptotic patterns induced by either the regularly spliced p53 product (p53RS) or a C'-terminally alternatively spliced p53 product (p53AS) were compared. We found that although both forms of p53 induced apoptosis following expression of the wild-type protein conformation, the kinetics were different. Apoptosis induced by the p53AS protein was attenuated compared to that induced by p53RS. The delay in the manifestation of the apoptotic features following p53AS expression was in agreement with a delay in the regulation of the expression of apoptosis-related genes. The observation that p53 with an altered C' terminus is still capable of inducing apoptosis suggests that the actual onset of the apoptotic process most probably involves structural domains other than the C' terminus of the p53 molecule. However, the fact that the apoptotic activity mediated by the p53AS product was slower than that mediated by the p53RS product suggests that the C' terminus indeed exerts a certain control on the apoptotic activity of the p53 molecule.

Inhibition of endogenous ganglioside synthesis does not block neurite formation by retinoic acid-treated neuroblastoma cells

Gangliosides are believed to play a critical role in cellular differentiation. To test this concept, we determined the effect of inhibition of endogenous ganglioside synthesis upon neurite formation induced by retinoic acid in LAN-5 human neuroblastoma cells. Ganglioside synthesis and content of LAN-5 cells exposed for 6 days to 10 microM D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP) (an inhibitor of glucosylceramide synthase) were reduced by >90%. However, these ganglioside-depleted cells were not blocked from forming neurites when exposed to 10 microM retinoic acid. Even more extensive treatment of LAN-5 cells with 20 microM D-PDMP (6 day pretreatment followed by 6 days together with 10 microM retinoic acid) still did not block the retinoic acid-induced neurite formation. An element of neuroblastoma tumor cell differentiation, neurite formation, is therefore dependent neither on an intact cellular ganglioside complement nor on new ganglioside synthesis.

Risk factors differ for carotid artery plaque with and without acoustic shadowing. Atherosclerosis Risk in Communities Study Investigators

To investigate the association of gender, ethnicity, and several cardiovascular risk factors with carotid artery plaque and plaque with acoustic shadowing in a population-based sample, high-resolution B-mode ultrasonography was used to characterize lesions in the common and internal carotid arteries, and at the carotid bifurcation in 12,796 US men and women, aged 45 to 64 years, participating in the Atherosclerosis Risk in Communities Study (ARIC) baseline survey. In multiple logistic regression analyses, male gender (odds ratio and 95% confidence interval: 1.52 [1.39-1.67]) and increased total (1.47 [1.32-1.63]) and low-density-lipoprotein cholesterol (1.49 [1.34-1.65]) levels were statistically significantly associated only with the presence of plaque. In contradistinction, smoking (2.22 [1.79-2.75]) and hypertension (1.54 [1.30-1.82]) were additionally associated with acoustic shadowing. Hyperfibrinogenemia (1.33 [1.12-1.59]) was associated only with lesions accompanied by acoustic shadowing. While ethnicity associations with plaque alone varied across the artery segments, among those with plaque, being white was uniformly associated with acoustic shadowing. After multivariable adjustment, high-density-lipoprotein cholesterol was not associated with either manifestation of atherosclerosis. In conclusion, differences were seen in the associations of established cardiovascular risk factors with discretely characterized carotid artery plaque lesions, according to the presence or absence of acoustic shadowing suggestive of mineralization of plaque.

Independent evolution of the prochlorophyte and green plant chlorophyll a/b light-harvesting proteins

The prochlorophytes are oxygenic prokaryotes differing from other cyanobacteria by the presence of a light-harvesting system containing both chlorophylls (Chls) a and b and by the absence of phycobilins. We demonstrate here that the Chl a/b binding proteins from all three known prochlorophyte genera are closely related to IsiA, a cyanobacterial Chl a-binding protein induced by iron starvation, and to CP43, a constitutively expressed Chl a antenna protein of photosystem II. The prochlorophyte Chl a/b protein (pcb) genes do not belong to the extended gene family encoding eukaryotic Chl a/b and Chl a/c light-harvesting proteins. Although higher plants and prochlorophytes share common pigment complements, their light-harvesting systems have evolved independently.

Lack of a pharmacologic interaction between rifabutin and methadone in HIV-infected former injecting drug users

Rifampin, an agent known to decrease the half-life of methadone, and rifabutin are two rifamycins that are structurally similar and share mechanisms of action. Hence the possibility of a drug-drug interaction between rifabutin and methadone was evaluated in 24 methadone-maintained, former injecting drug users infected with the human immunodeficiency virus. The study was an open-label, drug-drug interaction and safety trial in which patients were followed for 15 days. Each patient received rifabutin 300 mg as a single dose concomitantly with their individualized methadone dosage. No significant differences in methadone peak plasma concentration, time to peak plasma concentration, area under the plasma concentration-time curve, systemic clearance or renal clearance was observed in the presence of rifabutin. Seventy-five percent of the patients reported at least one symptom of narcotic withdrawal during the study, however, these symptoms were mild. A relationship between the development of narcotic withdrawal and methadone systemic exposure could not be established. Concurrent administration of rifabutin and methadone appeared to be safe in human immunodeficiency virus-infected injecting drug users maintained on stable doses of methadone and is not expected to produce any significant changes in the pharmacokinetics of methadone in these patients.

Leukocyte transmembrane potential in bipolar illness

Abnormalities in ion regulation and distribution are commonly reported in bipolar disorder. In an effort to determine if these alter cellular physiological function, we determined the transmembrane potential (TMP) in mononuclear leukocytes from normal individuals and patients with bipolar illness either during normal phase or manic and hypomanic episodes. TMP was analyzed by flow cytometry using dihexyloxacarbocyanine iodide (DIOC6(3)), a cationic potential sensitive fluorescent dye. A normal range was established from measurements on leukocytes from 5 control individuals. TMP of manic and hypomanic patients was significantly hyperpolarized (P = 0.0036). The TMP of euthymic bipolar individuals was not different from normal controls. Pathologic moods in bipolar illness may be associated with altered cellular membrane physiology.

A comparison of amino acid sequences of hepatitis B virus S gene in 46 children presenting various clinical features for immunoprophylaxis

We compared amino acid sequences of hepatitis B virus (HBV) S protein deduced from analyzed DNA sequence in 46 children who received immunoprophylaxis to prevent mother-to-child transmission of HBV. They were classified into 6 groups by their clinical features. The antibody escape mutants were found in 8 cases among 46 cases. We studied the difference in clinical features in these cases and speculated that 126 Ser or 140 Ser-strain may have a different behavior in relation to antibody to hepatitis B surface antigen from 126 Asn or 145 Arg-strain.

The role of p53 in the induction of polyploidity of myelomonocytic leukemic M1/2 cells

p53 was shown to play a central role in the maintenance of genomic integrity. The present experiments suggest that p53 is involved in the control of cell ploidity. Using a p53 non-producer cell line, M1/2, that was reconstituted to express either wild type or mutant p53 protein, by infection with the temperature sensitive (Ts) p53Val135 virus, it was found that both loss of wild type p53 or overexpression of mutant p53, may be associated with the generation of cell polyploidity. Overexpression of mutant p53 protein enhanced the appearance of giant cells that further accumulated following gamma-irradiation. Expression of wild type p53 reduced the level of giant cells which accumulated in the parental M1/2 p53 non-producer cells following gamma-irradiation. This activity of the wild type p53 seems to be mediated by either the reduction in the rate of giant cell generation, as observed in M1/2 derived cell lines expressing low levels of wild type p53 protein or by facilitating their apoptosis, as observed in wild type p53 high-producer cells. The latter conclusion is further supported by the observation that isolated giant cells are directly induced to undergo apoptosis following wild type p53 expression.

Abrogation of shedding of immunosuppressive neuroblastoma gangliosides

Shedding of tumor cell gangliosides may contribute to tumor cell escape from host immune destruction. Thus, it would be of interest to block the shedding of these immunosuppressive molecules. To this end, we studied a ceramide analogue, D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP). D-PDMP is a potent inhibitor of glucosylceramide synthase and thereby the synthesis of cellular glycosphingolipids. Exposure of LAN-5 human neuroblastoma cells to 10 microM D-PDMP for 5 days almost completely abolished the shedding of gangliosides (from 240 to 8 pmol/10(8) cells/h), whereas cellular ganglioside synthesis was reduced by 90%. A shorter (3-day) treatment of LAN-5 cells with 10 microM D-PDMP was already effective in inhibiting shedding (by 86%) even while the cellular ganglioside content was still high. Specificity was evidenced by the only minimal effect of D-PDMP on the synthesis of sphingomyelin and phosphatidylcholine. Therefore, certain pharmacological agents, such as D-PDMP, may be useful in abrogating tumor ganglioside shedding and its consequent biological effects in vivo.

Expression of the human cytochrome c1 gene is controlled through multiple Sp1-binding sites and an initiator region

It is widely accepted that nuclear genes that encode proteins of the oxidative-phosphorylation system are regulated by nuclear factors believed to be specific for such genes. In the present study we show that the promoter for the human cytochrome c1 gene is an exception, in that it involves only conserved Sp1 core elements and an initiator region. Maximal promoter activity within a 1.4-kb 5' flanking region of the cytochrome c1 gene is contained in a fragment (-72 to +18) that lacks TATA and CCAAT elements. The transcriptional start site was mapped to an initiator region by RNase protection of mRNA from human HepG2 cells, and by primer extension of in vitro-generated transcripts, to a sequence that is highly similar to the dihydrofolate reductase family of initiators. Deletion of this region (+1 to +18) severely impairs transcription initiation. Sp1 core elements centered at nucleotides -21 and -39 define the activation domain of the proximal promoter. Only the -39 element is protected from DNase I in the presence of crude nuclear extracts. However, transfection, gel-mobility-shift, supershift and in vitro-transcription experiments show that the -21 element binds Sp1 protein and contributes to transcription activation. No other functional oxidative-phosphorylation-specific response elements have been identified. These data implicate Sp1 as a single activating factor for an oxidative-phosphorylation gene.

Effects of chronic episodic hypoxia on monoamine metabolism and motor activity

Chronic episodic hypoxia produces a wide array of cardiovascular dysfunctions in rats, including increases in blood pressure, heart rate, and sympathetic nerve activity. The action of episodic hypoxia might be related to low oxygen itself (hypoxemia) and/or combined with low CO2 (hypocapnia) resulting from hyperventilation. It is unknown whether or not the cardiovascular abnormalities are related to alterations in the central nervous system (CNS) that may be manifested as neurotransmitter and/or behavioral changes. In this study, we investigated effects of episodic eucapnic and hypocapnic hypoxia on monoamine metabolism in both CNS and adrenal glands, and on motor behavioral activity. Thirty-five male rats were divided into 3 groups. Experimental rats were exposed 8 h daily to varying fractional concentrations of inspired oxygen (FiO2) and carbon dioxide (FiCO2) for 35 days. These consisted of brief exposures (3-6s) of episodic (twice every min) eucapnic (3.5% FiO2 and 10% FiCO2, n = 6) or hypocapnic (3.5% FiO2 and 0% FiCO2, n = 14) hypoxia, or room air (21% FiO2 and 0.03% FiCO2, n = 15). Norepinephrine, dopamine, serotonin, and their metabolites in the hypothalamus, hippocampus, and adrenal glands were measured by high-performance liquid chromatography (HPLC). Spontaneous behavioral activity was assessed for 30 min by automated activity monitors. Episodic hypocapnic hypoxia produced a decrease in dopamine turnover and eucapnic hypoxia increased norepinephrine levels in the hypothalamus. Animals exposed to hypocapnic hypoxia also exhibited a consistent increase in horizontal (walking) and vertical (rearing) activity, as well as in total activity time. From these results, it is concluded that episodic eucapnic and hypocapnic hypoxia may affect metabolism of different neurotransmitters in the CNS.

Multiple factors control the proliferation and differentiation of rat early embryonic (day 9) neuroepithelial cells

The proliferation and differentiation of neural precursor cells is largely controlled by environmental factors. By providing the factors that favor the proliferation or suppress the differentiation of this cell type, we isolated and expanded an early neuroepithelial pre-differentiated cell type from E9 rat neural plate in serum-free medium. This has led to the establishment of a neural epithelial precursor (NEP) cell line. The NEP cell's properties are substantially different from those of cell lines previously derived from neural tissue at later stages of development. Initial selection and survival of this cell type requires a factor secreted by an embryonic Schwann (nrESC) cell line. Continued passage of these cells requires cell-cell contact for both survival and growth. Neural cell differentiation can be induced in this nestin positive precursor cell line by bFGF and forskolin. General neuronal markers, as well as cortical neuron-specific protein kinase C isozyme, and accumulation of glutamate and aspartate were induced in most cells. Choline acetyl-transferase was also induced in a small number of cells. When implanted into neonatal rat brain, the NEP cell line gave rise to several distinct neuronal and glial phenotypes in different regions of the brain including cerebellar cortex and hippocampus.

Structure-based design of parasitic protease inhibitors

To streamline the preclinical phase of pharmaceutical development, we have explored the utility of structural data on the molecular target and synergy between computational and medicinal chemistry. We have concentrated on parasitic infectious diseases with a particular emphasis on the development of specific noncovalent inhibitors of proteases that play a key role in the parasites' life cycles. Frequently, the structure of the enzyme target of pharmaceutical interest is not available. In this setting we have modeled the structure of the relevant enzyme by virtue of its sequence similarity with proteins of known structure. For example, we have constructed a homology-based model of falcipain, the trophozoite cysteine protease, and used the computational ligand identification algorithm DOCK to identify in compuo enzyme inhibitors including oxalic bis(2-hydroxy-1-naphthyl-methylene)hydrazide (1) [Ring, C. S.; Sun, E.; McKerow, J. H.; Lee, G.; Rosenthal, P. J., Kuntz, I. D.; Cohen, F. E., Proc. Natl Acad. Sci. U.S.A. 1993, 90, 3583]. Compound 1 inhibits falcipain (IC50 6 microM) and the organism in vitro as judged by hypoxanthine uptake (IC50 7 microM). Following this lead, to date, we have identified potent bis arylacylhydrazides (IC50 150 nM) and chalcones (IC50 200 nM) that are active against both chloroquine-sensitive and chloroquine-resistant strains of malaria. In a second example, cruzain, the crystallographically determined structure of a papain-like cysteine protease, resolved to 2.35 A, was available. Aided by DOCK, we have identified a family of bis-arylacylhydrazides that are potent inhibitors of cruzain (IC50 600 microM). These compounds represent useful leads for pharmaceutical development over strict enzyme inhibition criteria in a structure-based design program.

A one-hand operation gun for transrectal prostate biopsy

OBJECTIVE

To develop a new automatic biopsy device (ABD) that enables a radiologist to obtain multiple samples with one hand and free the other hand to handle the ultrasonic scanner for continuous monitoring.

MATERIALS AND METHODS

The new ABD developed by us in April 1994 enabled a radiologist to complete all the biopsy procedures including loading and reloading the spring system, firing the device, emptying the specimen, selecting the depth of needle advancement, and multiple sampling, simply by pressing 3 buttons in turn with his/her right thumb. Using this new ABD, transrectal prostate biopsy under the guidance of transrectal ultrasonic imaging was performed in 60 consecutive cases of prostate diseases. Each biopsy procedure was completed by a single radiologist, who was able to obtain multiple specimens with one biopsy needle, using only one hand and freeing the other hand for the manipulation of the ultrasonic scanner for guidance.

RESULTS

A total of 265 satisfactory core tissue specimens of 285 needle passes (93%) were obtained from the 60 patients. Definite pathologic diagnoses were made for all the 60 patients (100%). No serious biopsy-related complications were observed. The main complications were hematuria in 24 of 60 (40%) patients and fever in 5 (8.3%).

CONCLUSION

On the basis of our experience with the 60 patients, this new ABD can be operated smoothly and effectively with the right hand, while the left hand is freed to handle the ultrasonic transducer for continuous monitoring.

Cyclic HIV protease inhibitors: synthesis, conformational analysis, P2/P2' structure-activity relationship, and molecular recognition of cyclic ureas

High-resolution X-ray structures of the complexes of HIV-1 protease (HIV-1PR) with peptidomimetic inhibitors reveal the presence of a structural water molecule which is hydrogen bonded to both the mobile flaps of the enzyme and the two carbonyls flanking the transition-state mimic of the inhibitors. Using the structure-activity relationships of C2-symmetric diol inhibitors, computed-aided drug design tools, and first principles, we designed and synthesized a novel class of cyclic ureas that incorporates this structural water and preorganizes the side chain residues into optimum binding conformations. Conformational analysis suggested a preference for pseudodiaxial benzylic and pseudodiequatorial hydroxyl substituents and an enantiomeric preference for the RSSR stereochemistry. The X-ray and solution NMR structure of the complex of HIV-1PR and one such cyclic urea, DMP323, confirmed the displacement of the structural water. Additionally, the bound and "unbound" (small-molecule X-ray) ligands have similar conformations. The high degree of preorganization, the complementarity, and the entropic gain of water displacement are proposed to explain the high affinity of these small molecules for the enzyme. The small size probably contributes to the observed good oral bioavailability in animals. Extensive structure-based optimization of the side chains that fill the S2 and S2' pockets of the enzyme resulted in DMP323, which was studied in phase I clinical trials but found to suffer from variable pharmacokinetics in man. This report details the synthesis, conformational analysis, structure-activity relationships, and molecular recognition of this series of C2-symmetry HIV-1PR inhibitors. An initial series of cyclic ureas containing nonsymmetric P2/P2' is also discussed.

The scl gene product is required for the generation of all hematopoietic lineages in the adult mouse

Homozygosity for a null mutation in the scl gene causes mid-gestational embryonic lethality in the mouse due to failure of development of primitive hematopoiesis. Whilst this observation established the role of the scl gene product in primitive hematopoiesis, the death of the scl null embryos precluded analysis of the role of scl in later hematopoietic development. To address this question, we created embryonic stem cell lines with a homozygous null mutation of the scl gene (scl-/-) and used these lines to derive chimeric mice. Analysis of the chimeric mice demonstrates that the scl-/- embryonic stem cells make a substantial contribution to all non-hematopoietic tissues but do not contribute to any hematopoietic lineage. These observations reveal a crucial role for the scl gene product in definitive hematopoiesis. In addition, in vitro differentiation assays with scl-/- embryonic stem cells showed that the scl gene product was also required for formation of hematopoietic cells in this system.

Sp1 activates and inhibits transcription from separate elements in the proximal promoter of the human adenine nucleotide translocase 2 (ANT2) gene

Expression of the adenine nucleotide translocator 2 (ANT2) gene is growth regulated. We report a feature of the ANT2 promoter that involves a novel regulatory function for the Sp1 transfactor. We show that expression from the ANT2 proximal promoter is modulated through three Sp1 elements, two of which activate and one of which partially inhibits transcription. The inhibitor site, box C, is juxtaposed to transcription start (nucleotides -7 to -2). Sp1 bound to box C decreases transcription initiation. This was demonstrated by introducing mutations in box C which (a) increased chloramphenicol acetyltransferase expression in the transient transfection assay and (b) inhibited binding of both purified Sp1 and Sp1 in crude nuclear extracts. The activating elements (A and B boxes) are located at adjacent sites in the distal region of the proximal promoter. Mutation of either box inhibits transfection by 90%, indicating that they act in a synergistic manner. Supershift experiments with crude nuclear extracts showed that only Sp1 was bound to the three GC boxes. The finding that Sp1 acts as an activator/inhibitor within the same promoter region was verified in NIH3T3, HeLa, JEG3, and COS-1, indicating that this dual effect of Sp1 is widely preserved. These data suggest a unique role for Sp1 and raise the possibility that growth activation of the ANT2 gene is regulated by the interaction of Sp1 on the A, B, and C boxes.

[Distribution of Bacillus thuringiensis in soils of north and south of China]

221 isolates of Bacillus thuringiensis were isolated in 1491 soil samples from North and South of China. H-serotypes and larvicidal characters of all Bt isolates have been identified. The rate of Bt-harbouring soil sample and the rate of Bt isolates in Northeast and Neimeng were in 12.6% and 17.2% respectively. Predominant serotypes were H4, H10, H3, H13, H5 and H29. The most fertile Bt-harbouring area was the Heilongjiang Province with rate of Bt-harbouring sample of 21.4% and rate of Bt isolate of 29.4%. Rate of Bt-harbouring sample and rate of Bt isolate in Northwest area were 6.6% and 7.1% respectively. Main serotypes were H4, H5, H19, H10 and H3. In four provinces of Southern China, both rates above were 18.6% and 29.5%, but frequency of Bt distribution was varied seriously in different distinct. Predominant serotypes in soils from Southern China were H3 and H5. Results of bioassay showed that the percentage of strains high active to Heliothis armigera and Plogioidera versicolora were 1.6% and 1.1% in soils from North of China. In contrast to North of China, Bt strains active to H. armigera were 5.3% and none of Bt was effective to P. versicolora in South of China. A strain H27-05 was high toxic to H. armigera and showed temperate toxicity to P. versicolora.

Host range restrictions of oncogenes: myc genes transform avian but not mammalian cells and mht/raf genes transform mammalian but not avian cells

The host range of retroviral oncogenes is naturally limited by the host range of the retroviral vector. The question of whether the transforming host range of retroviral oncogenes is also restricted by the host species has not been directly addressed. Here we have tested in avian and murine host species the transforming host range of two retroviral onc genes, myc of avian carcinoma viruses MH2 and MC29 and mht/raf of avian carcinoma virus MH2 and murine sarcoma virus MSV 3611. Virus vector-mediated host restriction was bypassed by recombining viral oncogenes with retroviral vectors that can readily infect the host to be tested. It was found that, despite high expression, transforming function of retroviral myc genes is restricted to avian cells, and that of retroviral mht/raf genes is restricted to murine cells. Since retroviral oncogenes encode the same proteins as certain cellular genes, termed protooncogenes, our data must also be relevant to the oncogene hypothesis of cancer. According to this hypothesis, cancer is caused by mutation of protooncogenes. Because protooncogenes are conserved in evolution and are presumed to have conserved functions, the oncogene hypothesis assumes no host range restriction of transforming function. For example, mutated human proto-myc is postulated to cause Burkitt lymphoma, because avian retroviruses with myc genes cause cancer in birds. But there is no evidence that known mutated protooncogenes can transform human cells. The findings reported here indicate that host range restriction appears to be one of the reasons (in addition to insufficient transcriptional activation) why known, mutated protooncogenes lack transforming function in human cells.

Polymorphism and crystallization behavior of Abbott-79175, a second-generation 5-lipoxygenase inhibitor

The crystal polymorphism of Abbott-79175, a potent second-generation 5-lipoxygenase inhibitor, has been studied. Crystallization from an ethyl acetate/heptane system in which moisture content was not controlled and from an ethanol/water system produced a crystal form I, which by differential scanning calorimetry, thermogravimetric analysis, and Karl Fischer analysis was likely a hemihydrate. This hemihydrate form of the compound was demonstrated to reversibly dehydrate/hydrate with the use of low heat and vacuum followed by exposure to water vapor (100% relative humidity). The dehydrated version of I was designated IA. However, it was shown that a relative humidity approaching 100% was required for the water to re-enter the crystal structure. X-ray powder diffraction and solid state 13C NMR data on polycrystalline samples crystallized from seven single organic solvents suggested two nonsolvated forms of the compound, II and III. The heptane addition rate to a dry ethyl acetate solution of the drug was shown to greatly affect the crystal habit, the crystallite size, and specific surface area upon its precipitation. Solution calorimetry of forms I, IA, and II showed that I had the most endothermic heat of solution, with IA and II having lower values. Initial dissolution rates of compressed disks of these forms in water showed rates of IA > II approximately I. Considering all data, including evidence of conversion of II to I in aqueous suspension, it is suggested that the relative thermodynamic stability (at least when water was present) in decreasing order is I > II > IA, although I and II are similar energetically. The lower terminal dissolution rate for form IA was due to, in part, conversion to the less soluble Form I.

The nu gene acts cell-autonomously and is required for differentiation of thymic epithelial progenitors

The nude mutation (nu) causes athymia and hairlessness, but the molecular mechanisms by which it acts have not been determined. To address the role of nu in thymogenesis, we investigated whether all or part of the nude thymic epithelium could be rescued by the presence of wild-type cells in nude <--> wild-type chimeric mice. Detailed immunohistochemical analyses revealed that nude-derived cells could persist in the chimeric thymus but could not contribute to cortical or medullary epithelial networks. Nude-derived cells, present in few clusters in the medulla, expressed markers of a rare subpopulation of adult medullary epithelium. The thymic epithelial rudiment of nude mice strongly expressed these same markers, which may therefore define committed immature thymic epithelial precursor cells. To our knowledge, these data provide the first evidence that the nu gene product acts cell-autonomously and is necessary for the development of all major subpopulations of mature thymic epithelium. We propose that nu acts to regulate growth and/or differentiation, but not determination, of thymic epithelial progenitors.

[Subcellular location of blood group substances ABH using transmission electron microscopical immunocytochemistry technique]

The subcellular location of blood group substances ABH was studied by using transmission electron microscopical immunocytochemistry. The cells were the epithelial cells of both mucous membranes and glands of normal human stomach, duodenum and transverse colon. Both cellular ultrastructure and antigens should be well preserved in transmission electron microscopical immunocytochemistry. In this paper, various fixatives, embedding media and immunostaining methods were investigated and compared. The results indicate that the solution containing 2% paraformaldehyde and 0.2% glutaraldehyde (2PG) is the best fixative and Epon 812 medium is the best embedding medium for preserving ABH antigens and protecting cellular ultrastructure. Post-embedding immunogold staining technique is superior to pre-embedding immunoperoxidase staining.

The expression of c-erbB-1 and c-erbB-2 oncogenes in basal cell carcinoma and squamous cell carcinoma of skin

The expression of c-erbB-1 and c-erbB-2 oncogenes were investigated by immunohistochemistry using monoclonal antibodies to c-erbB-1 and c-erbB-2 protein in 43 cases of basal cell carcinoma (BCC) and 26 cases of squamous cell carcinoma (SCC). We found that the expression of c-erbB-1 oncogene in all BCC increased by different degrees and the expression of c-erbB-2 oncogene in BCC was significantly reduced or lost when compared to that in normal epidermal cells. Furthermore, apparent negative and positive relationships were observed respectively between the tumor differentiation and the expression of c-erbB-1 and c-erbB-2 oncogenes in SCC. It is suggested that the abnormal expression of c-erbB-1 and c-erbB-2 oncogenes in BCC and SCC may play a role in the development of skin tumors. The pattern of the c-erbB-1 and c-erbB-2 oncogenes expression in SCC may assist in distinguishing the biological behavior and prognosis of SCC.

Structural characterization and in vivo immunosuppressive activity of neuroblastoma GD2

Shedding of neuroblastoma gangliosides is positively correlated with tumour progression in patients with neuroblastoma. In assessing the biological activity of these ganglioside molecules, we recently found that total human neuroblastoma gangliosides inhibit cellular immune responses. Here, we have studied the major neuroblastoma ganglioside, GD2. GD2 was purified by high performance liquid chromatography and structurally characterized by mass spectrometry. Immunoregulatory effects of GD2 in vivo were then determined in an established murine model. GD2 significantly downregulated the local cellular immune response to an allogeneic cell challenge; the usual increase in mass of the lymph node draining the injection site was reduced by 88%, from 1.52 to 0.19 mg (control versus GD2-treated mice; p < 0.01). In parallel, lymphocyte recovery from each node was also reduced from 2.4 to 1.2 x 10(6) cells, and lymphocyte DNA synthesis was reduced to half of the control level. These results show that certain shed tumour gangliosides, such as GD2, function as intercellular signalling molecules, downregulate the cellular immune response, and may thereby enhance tumour formation and progression.

[Fertilization in vitro and embryo transfer by combined long-acting gonadotropin releasing hormone agonist and gonadotropin for superovulation in patients with refractory polycystic ovary syndrome]

OBJECTIVE

To investigate the efficacy of the treatment for polycystic ovary syndrome (PCOS) patients by combined long acting gonadotropin-releasing hormone agonist (GnRHa) and gonadotropin.

METHODS

Nineteen women with PCOS who had failed to conceive on treatment with conventional fertilization in vitro-embryo transfer (IVF-ET) protocol underwent 26 cycles of IVF-ET by combined long-acting and gonadotropin stimulation. A self-control group consisted of 19 PCOS women who had received 19 treatment cycles with conventional IVF-ET stimulation protocol more than 6 months previously.

RESULTS

A comparison of these two groups showed that treatment with combined long-acting GnRHa and gonadotropin improved the in vitro fertility rate (76.2%) and pregnancy rate (38.5%).

CONCLUSION

Patients with refractory PCOS should be referred for IVF-ET, using long-acting GnRHa before gonadotropin as the stimulation protocol.

[Dynamic assay of oleanolic acid in Aralia taibaiensis Z. Z. Wang et H. C. Zheng]

The dynamic assay on oleanolic acid (OA) in Aralia taibaiensis shows that the plant has a higher OA level. The level in root cortex is 4.74%-10.81% and peak stages are mid-May to late June and late August to mid-September the level in stem barks is 3.59%-12.06% and peak period is between mid-May and late July, the level in leaves increases throughout the life time ranging from 2.41% to 6.66% and peak level is 6.66% around mid-September.

[Cloning and sequencing the isopenicillin N synthetase(IPNS) gene from Streptomyces cattleya]

Great homology existed between IPNS genes from surphur-containing beta-lactam antibiotics producers including procaryotes and eucaryotes. A DNA homologous band was confirmed in S. cattleya by Southern blot analysis using IPNS gene from S. lipmanii as a probe. A recombinant plasmid containing the cyclase gene involved in thienamycin biosynthesis and IPNS gene was obtained by complementary cloning with mutant from S. cattleya. DNA sequencing revealed that the IPNS gene of S. cattleya consists of 963 bp encoding a protein of 321 amino acids with ATG as start codon, TGA as stop codon. Pairwise comparison of the predicted amino acid sequences showed 56% and 64% similarity with IPNSs of S. clavuligerus and S. lipmanii, respectively.

Deficiencies in progenitor cells of multiple hematopoietic lineages and defective megakaryocytopoiesis in mice lacking the thrombopoietic receptor c-Mpl

Mice with a null mutation in the thrombopoietin (TPO) receptor c-Mpl were generated by gene targeting. c-mpl-deficient mice developed normally but were deficient in megakaryocytes and severely thrombocytopenic. The hematocrit and numbers of mature circulating leukocytes were normal in mpl-/- mice, as was the distribution of morphologically identifiable precursors in hematopoietic tissues. Bone marrow and spleen cells of adult mpl-/- mice lacked specific binding sites for TPO, were unresponsive to TPO in culture, and displayed a marked deficiency in progenitor cells with megakaryocytic potential. Significantly, total hematopoietic progenitor cell numbers were also reduced in mpl-/- mice including multipotential, blast cell, and committed progenitors of multiple lineages. The megakaryocyte deficiency was evident as early as 14 days of gestation in mpl-deficient mice, although reductions in progenitor cell numbers arose only later in development. The data suggest that the critical function of c-Mpl signalling in megakaryocytopoiesis is in maintenance of mature megakaryocyte numbers through control of progenitor cell proliferation and maturation. Moreover, our results also imply an important role for TPO and c-Mpl in the production of primitive pluripotent progenitor cells as well as progenitor cells committed to nonmegakaryocytic lineages.

Identification of Gas6 as a growth factor for human Schwann cells

Schwann cells are one of the principal components of the peripheral nervous system. They play a crucial role in nerve regeneration and can be used clinically in the repair of injured nerves. We have established serum-free, defined culture conditions that rapidly expand adult human Schwann cells without fibroblast growth. We find that Gas6, a ligand for the Axl and Rse/Tyro3 receptor protein tyrosine kinase family, stimulates human Schwann cell growth, increasing both cell number and thymidine incorporation. Gas6 has synergistic effects with the other known human Schwann cell mitogens, heregulin/glial growth factor and forskolin. Addition of Gas6 causes phosphorylation of Axl and Rse/Tyro3 simultaneously and results in ERK-2 activation. A combination of Gas6 with heregulin and forskolin, on a defined background, supports maximal Schwann cell proliferation, while preserving the typical Schwann cell morphology and expression of the Schwann cell markers S-100, glial fibrillary acidic protein, and low-affinity nerve growth factor receptor. Gas6 mRNA is present in both spinal motor neurons and large neurons of the dorsal root ganglia, and neural injury has been reported to upregulate Rse/Axl in the schwann cell. This is the first demonstration of a potentially important biological role for the human Gas6/Rse-Axl system.

Increased plasma rifabutin levels with concomitant fluconazole therapy in HIV-infected patients

OBJECTIVE

To determine the effect of fluconazole on rifabutin pharmacokinetics.

DESIGN

An open-label, crossover, phase 1 trial.

SETTING

Outpatient clinical research center at a university medical center in Washington, D.C.

PATIENTS

12 persons with human immunodeficiency virus (HIV) infection whose CD4 lymphocyte counts were between 200 and 500 cells/mm3 and who were receiving maintenance therapy with zidovudine.

INTERVENTION

Fluconazole, 200 mg/d for 2 weeks; then a combination of fluconazole, 200 mg/d, and rifabutin, 300 mg/d, for 2 weeks; and then rifabutin, 300 mg/d, for the final 2 weeks of the study.

MEASUREMENTS

Blood and urine samples were obtained at regular intervals for 24 hours at the end of each 2-week dosing period to ascertain concentrations of fluconazole and rifabutin and the 25-desacetyl metabolite of rifabutin, LM565.

RESULTS

Fluconazole significantly increased the plasma concentrations of both rifabutin and LM565. Mean increases in the area under the plasma concentration curve compared with the time curve over a 24-hour dosing interval were 82% (5442 +/- 2404 ng.h/mL compared with 3025 +/- 1117 ng.h/mL; P less than or equal to 0.05) for rifabutin and 216% (959 +/- 529 ng.h/mL compared with 244 +/- 141 ng.h/mL; P less than or equal to 0.05) for LM565.

CONCLUSIONS

Fluconazole significantly increases the systemic exposure of both rifabutin and LM565. This pharmacokinetic interaction offers a mechanism that may explain the changes reported in both the efficacy and toxicity of rifabutin with concomitant fluconazole therapy.