Oxygen transfer characteristics in the compact callus aggregates of Rhodiola sachalinensis

The effective diffusivity of oxygen in compact callus aggregates (CCA) of Rhodiola sachalinensis was extremely small, varying from 0.34 x 10(-11) to 5.4 x 10(-9) m2/s and increasing with particle diameter. The calculated results indicated that severe oxygen limitations occurred in the CCA aggregates. However, the direct determination of the viability of the cells demonstrated that the CCA aggregates contained a high fraction of viable cells. It was suggested that the tissue differentiation or plasmodesmata within the CCA aggregates may provide capillaries for improving transport of oxygen and other nutrients.

Activating Smoothened mutations in sporadic basal-cell carcinoma

Basal-cell carcinomas (BCCs) are the commonest human cancer. Insight into their genesis came from identification of mutations in the PATCHED gene (PTCH) in patients with the basal-cell nevus syndrome, a hereditary disease characterized by multiple BCCs and by developmental abnormalities. The binding of Sonic hedgehog (SHH) to its receptor, PTCH, is thought to prevent normal inhibition by PTCH of Smoothened (SMO), a seven-span transmembrane protein. According to this model, the inhibition of SMO signalling is relieved following mutational inactivation of PTCH in basal-cell nevus syndrome. We report here the identification of activating somatic missense mutations in the SMO gene itself in sporadic BCCs from three patients. Mutant SMO, unlike wild type, can cooperate with adenovirus E1A to transform rat embryonic fibroblast cells in culture. Furthermore, skin abnormalities similar to BCCs developed in transgenic murine skin overexpressing mutant SMO. These findings support the role of SMO as a signalling component of the SHH-receptor complex and provide direct evidence that mutated SMO can function as an oncogene in BCCs.

TACHY: an expert system for the management of supraventricular tachycardia in the elderly

PURPOSE

Many physicians find the management of supraventricular tachyarrhythmia (SVT) in the elderly complex and challenging. With the use of artificial intelligence theory, we developed an interactive computer expert system, TACHY, to recommend therapies and warn physicians of potential therapeutic side effects.

METHODS

We developed a knowledge base that stores guidelines for the management of SVT in the elderly. After the diagnosis of current SVT was input into the computer, TACHY generated a list of therapeutic options as hypotheses. TACHY then prompted the user to provide current patient-specific clinical information, and the optimal therapeutic option was then selected. Potential therapeutic side effects were also displayed. TACHY was tested in a retrospective and a prospective study. The retrospective study, comprising 96 patients with 126 episodes of SVT, was performed to determine the concordance of therapy between TACHY and cardiologists. A prospective study in 18 patients with 26 episodes of SVT was also performed to validate TACHY's recommendations in restoring sinus rhythm.

RESULTS

In the retrospective study the concordance between TACHY and the cardiologist's first therapeutic option was 95.9% (121 of 126 episodes). In the prospective study sinus rhythm was restored in 18 (69%) of 26 episodes of SVT by the first therapeutic option recommended by TACHY. In the remaining eight episodes use of the second or third suggestion of TACHY was successful in controlling the ventricular response to SVT. No adverse reaction to the therapeutic options suggested by TACHY occurred.

CONCLUSION

TACHY, a knowledge-based computer expert system that simulates human decision making, produced promising results in the management of SVT in the elderly.

[Determination of etoposide (VP16) in human serum by high performance liquid chromatography]

A rapid high performance liquid chromatographic method for the determination of etoposide (VP16) in human serum has been developed. The samples were added teniposide (VM26) as an internal standard, extracted with ethyl acetate and chromatographed on a reversed phase YWG-C18 column with UV detection at 254 nm. The mobile phase was CH3OH:H2O = 55:45 (V/V). The calibration curve was Y = 0.0160 + 0.034X, r = 0.9991. It was reticlinear in the range between 0.5-50 mg/L. The detection limit was 0.1 mg/L. The average recovery was 95.0% +/- 0.2%. Intra-day and inter-day RSD were 4.16% and 4.76% respectively. From the results it can be concluded that this method is reliable. This method has been used to determine VP16 concentration in patient serum. The data obtained showed that the sensitivity and selectivity of this method were adequate for drug monitoring in clinical research.

[Cloning and expression of the E. coli serine hydroxymethyltransferase gene (glyA)]

The E. coli K12 glyA gene(13 kb), encoding serine hydroxymethyltransferase (SHMT), has been cloned in the plasmid vector pBR329 using insertion inactivation and complementation test. Subcloning of segments of the original insert (13 kb) into plasmids pBR322, pBR329 and pSMY901 established that a 2.6 kb PstI-EcoR fragment carries the glyA gene. The 12 strains of transforments containing recombined plasmid. were obtained. SHMT and glyA gene product level in strains carrying glyA plasmids were different. No SHMT activity was observed in host strains. The glyA gene products for JM109(pSM13), K12(pSM13), K12(pSM14) and K12(pSM15) account for 15.7%, 15.4%, 11.8%, and 9.48% of the total dissoluble cell protein, respectively.

Resistance to thyrotropin (TSH) in three families is not associated with mutations in the TSH receptor or TSH

Resistance to TSH (RTSH) is a recently described syndrome of reduced sensitivity to TSH that manifests as euthyroid hyperthyrotropinemia. It is usually identified at birth during routine neonatal screening for congenital hypothyroidism. In less than 2 yr, 13 subjects with RTSH belonging to 8 families have been reported, and all were shown to harbor mutations in the TSH receptor (TSHR) gene. We now report the occurrence of RTSH in 3 unrelated families. Contrary to previous reports, the inheritance of RTSH in 2 of the families was dominant rather than recessive and was not associated with abnormalities in the TSHR gene. Abnormalities in the TSHR gene were excluded by sequencing all coding sequences, exon/intron junctions, and the promoter region of the gene. Furthermore, the involvement of the TSHR in the manifestation of the RTSH phenotype was excluded in 2 families by linkage analysis using intragenic polymorphic markers. We excluded defects in the TSH beta-subunit by sequencing its gene and by showing that the circulating TSH in affected subjects from all families had normal bioactivity. Also, no abnormalities were found in the Gs alpha gene of one family analyzed by GC-clamped denaturing gradient gel electrophoresis. This study shows that RTSH may be a manifestation of several different genetic defects that requires the exploration of other candidate genes involved in the TSH-TSHR-Gs alpha cascade and genes participating in its regulation.

Mutation analysis of the gonadotropin-releasing hormone receptor gene in idiopathic hypogonadotropic hypogonadism

OBJECTIVE

To determine if GnRH receptor mutations occur in patients with idiopathic hypogonadotropic hypogonadism.

DESIGN

Patients and controls were studied by molecular genetic analysis.

SETTING

A tertiary medical center setting.

PATIENT(S)

Twenty-four patients with idiopathic hypogonadotropic hypogonadism and 20 controls.

INTERVENTION(S)

Deoxyribonucleic acid from all individuals was analyzed by Southern blot analysis and denaturing gradient gel electrophoresis. Genomic DNA was digested with restriction enzymes, and Southern blots and denaturing gradient gel blots were constructed. Blots were hybridized with the GnRH receptor complementary DNA probe. The DNA sequencing was performed on samples from two representative patients.

MAIN OUTCOME MEASURE(S)

Gonadotropin-releasing hormone receptor gene structure was ascertained by comparing fragments from autoradiographs in patients and controls. Individual nucleotides were ascertained from DNA sequencing gels.

RESULT(S)

No GnRH receptor gene deletions or polymorphisms were identified by Southern blot analysis. New restriction-fragment melting polymorphisms using the enzymes DpnII, RsaI, and HaeIII were identified by denaturing gradient gel blots in patients and controls.

CONCLUSION(S)

Gonadotropin-releasing hormone receptor gene deletions or rearrangements were not observed in our idiopathic hypogonadotropic hypogonadism patients. Denaturing gradient gel electrophoresis failed to identify single-base differences unique to patients with idiopathic hypogonadotropic hypogonadism, dramatically reducing the likelihood that point mutations of the GnRH receptor gene are present in idiopathic hypogonadotropic hypogonadism.

[Determination of demethylvancomycin in neonate serum by high performance liquid chromatography]

A rapid high performance liquid chromatography for determination of demethylvancomycin in neonate serum has been developed. The procedure involved a simple protein precipitation by acetonitrile-isopropanol (1:1) and then the sample was chromatographed on a reversed phase C18 column with UV detection at 236 nm. The mobile phase was CH3CN: 0.05 mol/L KH2PO4 = 8:92 (V/V). The calibration curve was Y = 35,721.89X - 13,031.54, r = 0.9998 and he detection limit was 0.3 mg/L. The average recovery was 94.7% +/- 1.2%. Intra-day and inter-day RSD were 2.23% and 2.62% respectively. It can be concluded that this method meets the requirement for routine clinical application. This method has been used to determine serum concentration of demethylvancomycin in neonates. The data obtained showed that the method was simple, rapid, sensitive and precise.

Function of the R domain in the cystic fibrosis transmembrane conductance regulator chloride channel

For a cystic fibrosis transmembrane conductance regulator (CFTR) channel to enter its open state, serine residues in the R domain must be phosphorylated by cAMP-dependent protein kinase, and intracellular ATP must bind to the nucleotide-binding folds and subsequently be hydrolyzed. CFTR with its R domain partially removed, DeltaR(708-835)-CFTR, forms a chloride channel that opens independently of protein kinase A phosphorylation, with open probability approximately one-third that of the wild type CFTR channel. Deletion of this portion of the R domain from CFTR alters the response of the channel to 5'-adenylylimidodiphosphate, pyrophosphate, and vanadate, compounds that prolong burst duration of the wild type CFTR channel but fail to do so in the DeltaR-CFTR. In addition, the addition of exogenous unphosphorylated R domain protein, which blocks the wild type CFTR channel, has no effect on the DeltaR-CFTR channel. However, when the exogenous R domain is phosphorylated, significant stimulation of the DeltaR-CFTR channel results; Po increases from 0.10 to 0.22. These data are consistent with a model for CFTR function in which the R domain in the unphosphorylated state interacts with the first nucleotide binding fold to inhibit either binding or hydrolysis of ATP or transduction of the effect to open the pore, but when the R domain is phosphorylated, it undergoes conformational change and interacts at a separate site in the first nucleotide binding fold to stimulate either binding or hydrolysis of ATP or transduction of the effect to open the pore.

[Taxonomic studies of two Streptomycete strains AS 4.693 and AS 4.702]

The "setae group" of the genus Streptomyces was originally the genus Kitasatosporia (Omura, 1982). On the basis of 16s rRNA analysis, Wellington(1992) proposed to reduce Kitasatosporia to synonymy with Streptomyces as a species group--"setae group". Two Streptomyces strains, AS 4.693 and AS 4.702(deposited in CCCCM) were examined by using morphological, chemical and nucleic acid ribtyping methods. It was revealed that these two strains have similarity to the type strain Streptomyces setae JCM3304T, and they share 100% DNA homology with JCM 3304T. Therefore, we propose that the strain AS 4.693 be transferred to the "setae group" of genus Streptomyces as Streptomyces setae subsp. irregularis nov. and the strain AS 4.702 as Streptomyces setae subsp. flexuofradiae nov.

MNDA binds NPM/B23 and the NPM-MLF1 chimera generated by the t(3;5) associated with myelodysplastic syndrome and acute myeloid leukemia

The myeloid cell nuclear differentiation antigen (MNDA) is a nuclear protein expressed specifically in developing cells of the human myelomonocytic lineage, including the end-stage monocytes/macrophages and granulocytes. Nuclear localization, lineage- and stage-specific expression, association with chromatin, and regulation by interferon alpha indicate that this protein is involved in regulating gene expression uniquely associated with the differentiation process and/or function of the monocyte/macrophage. MNDA does not bind specific DNA sequences, but rather a set of nuclear proteins that includes nucleolin (C23). Both in vitro binding assays and co-immunoprecipitation were used to demonstrate that MNDA also binds protein B23 (nucleophosmin/NPM). Three reciprocal chromosome translocations found in certain cases of leukemia/lymphoma involve fusions with the NPM/B23 gene, t(5;17) NPM-RARalpha, t(2;5) NPM-ALK, and the t(3;5) NPM-MLF1. In the current study, MNDA was not able to bind the NPM-ALK chimera originating from the t(2;5) and containing residues 1-117 of NPM. However, MNDA did bind the NPM-MLF1 product of the t(3;5) that contains the N-terminal 175 residues of NPM. The additional 58 amino acids (amino acids 117-175) of the NPM sequence that are contained in the product of the NPM-MLF1 fusion gene relative to the product of the NPM-ALK fusion appear responsible for MNDA binding. This additional NPM sequence contains a nuclear localization signal and clusters of acidic residues believed to bind nuclear localization signals of other proteins. Whereas NPM and nucleolin are primarily localized within the nucleolus, MNDA is distributed throughout the nucleus including the nucleolus, suggesting that additional interactions define overall MNDA localization.

Ethanol inhibits inducible nitric oxide synthase transcription and post-transcriptional processes in vivo

The effects of ethanol (ETOH) on post-transcriptional regulation of inducible nitric oxide synthase (iNOS) in vivo has not been demonstrated. We examined the effect of ETOH on iNOS mRNA, protein, and the production of the nitrate and nitrite anion (RNI) in rat lung alveolar macrophages (AM) in vivo when stimulated by lipopolysaccharide (LPS) and dibutyryl cyclic AMP (DB-cAMP). Sprague-Dawley rats (225-250 g) (n = 5-7/gp) were given intratracheal LPS (0.6 mg/kg) or DB-cAMP (0.1 and 1 mg/kg) 30 min after ETOH (4 mg/kg, intraperitoneally (ip)) or phosphate-buffered sterile saline (PBS) (5 ml/kg, ip) or pyrrolidine dithiocarbamate (PDTC 10 mg/kg, intratracheally) or 15 min after diethyl dithiocarbamate (DETC) (5 mg/kg, intratracheally). At selected times after administration of LPS or DB-cAMP, the animals were anesthetized, the lungs with the heart attached were removed and the lungs subjected to bronchoalveolar lavage (BAL). The BAL fluid was assayed for tumor necrosis factor alpha (TNF alpha) and RNI. The BAL fluid AM were isolated and analyzed for iNOS mRNA and protein with competitor-equalized polymerase chain reaction (PCR) and Western blots, respectively. The ex vivo incubates of AM were assayed for RNI and TNF alpha. LPS and DB-cAMP each increased iNOS mRNA and protein in AM and RNI in the BAL fluid and ex vivo incubates of AM. However, the peak of the increase of iNOS mRNA occurred at 2 hr for DB-cAMP and 4 to 6 hr for LPS. Only LPS increased the concentrations of TNF alpha in BAL fluid and ex vivo incubates of AM. ETOH attenuated LPS-mediated up-regulation of iNOS mRNA and TNF alpha and iNOS protein and RNI produced by the AM. In contrast, pretreatment of rats with ETOH did not affect DB-cAMP-mediated increases of iNOS mRNA in AM at any time but suppressed the amount of iNOS protein and RNI produced in DB-cAMP-stimulated AM. DETC, but not PDTC, attenuated LPS-mediated up-regulation of iNOS mRNA without effects on that produced by DB-cAMP. Since ETOH and DETC, but not PDTC, suppressed LPS-mediated but not DB-cAMP-mediated transcription of iNOS, we conclude that two distinct pathways exist for induction of iNOS mRNA by these agonists. ETOH and DETC may inhibit the LPS-mediated activation pathway by acting as antioxidants. Also, since ETOH inhibited DB-cAMP-mediated increases in iNOS protein without affecting iNOS mRNA ETOH also acts at a post-transcriptional or translational site to inhibit iNOS protein in rat AM in vivo.

Effects of NO synthase inhibitors, arginine-deficient diet, and amiloride in pregnant rats

This study tests the hypothesis that nitric oxide synthase (NOS) inhibition is linked to NG-nitro-L-arginine methyl ester (L-NAME)-mediated intrauterine growth retardation (IUGR) and fetal limb reduction deficits (LRD) in pregnant dams. Administration of L-NAME (1 mg/ml) or aminoguanidine (AG, 500 micrograms/ml) in the drinking water or intraperitoneal administration of L-N5-(1-iminoethyl)-ornithine (L-NIO, 10 mg.kg-1.day-1) on gestational days 13-20 decreased nitrite and nitrate plus nitrate (RNI) levels in the urine and plasma and decreased RNI in incubates of aorta and fetal limbs compared with pregnant rats given amiloride (50 micrograms/ml) or water (control). Although all drugs caused fetal IUGR, only L-NAME and amiloride caused fetal deaths and LRD. Urine and tissue levels of RNI were unchanged in rats fed and arginine-free diet (AFD) on gestational days 13-20, and yet fetal IUGR, deaths, and LRD were prevalent. L-NAME potentiated the fetal abnormalities and resorptions. Plasma arginine concentrations decreased with AFD > > L-NAME > L-NIO. Plasma ornithine, a precursor for polyamine synthesis, decreased with AFD and increased with L-NAME. Thus inhibition of NOS is not linked to LRD. The ability of L-NAME and amiloride to produce fetal IUGR and LRD may result from L-NAME-mediated modulation of amino acid delivery to the fetus and amiloride-mediated inhibition of protein synthesis. Finally, IUGR appears unrelated to LRD.

Interaction of ethanol with inducible nitric oxide synthase messenger RNA and protein: direct effects on autacoids and endotoxin in vivo

Inducible nitric oxide synthase (iNOS) mRNA is up-regulated in vivo by dibutyryl-cAMP (db-cAMP), the purine-2y receptor agonist 2-methylthio-ATP and Escherichia coli endotoxin lipopolysaccharide (LPS). Ethanol and diethyldithiocarbamate inhibit LPS-stimulated iNOS mRNA. Their effects on db-cAMP- and 2-methylthio-ATP-stimulated iNOS mRNA remain undefined. We examined the effect of ethanol (4.5 g/kg intraperitoneal) and intratracheal diethyldithiocarbamate (5 mg/kg) on intratracheal LPS (0.6 mg/kg), db-cAMP (0.1 and 1 mg/kg) or 2-methylthio-ATP (5 mg/kg)-stimulated rat alveolar macrophage (AM) iNOS mRNA and protein, reactive nitrogen intermediates nitrite and nitrate anion (RNI) and nuclear transcription factor-kappaB (NF-kappaB) in vivo. LPS and the autacoids increased iNOS mRNA and protein in rat AM and RNI in bronchoalveolar lavage fluid and in ex vivo incubates of AM compared with these parameters in control rats (n = 6-21/group). Only LPS up-regulated TNF-alpha mRNA and release of TNF-alpha in bronchoalveolar lavage fluid and AM. Ethanol inhibited LPS stimulation of the iNOS cascade at the level of transcription but inhibited only autacoid-stimulated iNOS protein and RNI. Diethyldithiocarbamate selectively inhibited the LPS-stimulated iNOS cascade at the level of transcription. Coadministration of ethanol and diethyldithiocarbamate inhibited LPS-stimulated iNOS mRNA, protein and RNI more than either inhibitor alone but did not differ from ethanol alone on autacoid-stimulated iNOS protein or RNI. LPS increased and db-cAMP did not affect NF-kappaB in AM. Ethanol inhibited LPS-stimulated NF-kappaB. Thus, two distinct pathways exist for induction of iNOS mRNA in rat AM in vivo: an NF-kappaB pathway for LPS and cytokines inhibitable by ethanol and diethyldithiocarbamate and an NF-kappaB-independent pathway, refractory to inhibition by ethanol and diethyldithiocarbamate for db-cAMP and 2-mes-ATP. Finally, ethanol inhibits iNOS at the level of transcription and at the level of the enzyme.

High-energy defibrillation increases the severity of postresuscitation myocardial dysfunction

BACKGROUND

The fatal outcome of victims after initially successful resuscitation from cardiac arrest has been attributed both to global myocardial ischemia during the interval of cardiac arrest and to the adverse effects of reperfusion. The present study was prompted by earlier experimental observation that the magnitude of myocardial dysfunction was in part related to the energy delivered during electrical defibrillation.

METHODS AND RESULTS

Ventricular fibrillation (VF) was induced in 15 Sprague-Dawley rats. Precordial compression was begun together with mechanical ventilation after 4 minutes of untreated VF and continued for 6 minutes. Spontaneous circulation was restored in each animal after external defibrillation with a single stored 2-, 10-, or 20-J countershock. Cardiac index and the rate of left ventricular pressure rise at left ventricular pressure of 40 mm Hg (dP/dt40) and fall (negative dP/dt) during the 240-minute interval after successful resuscitation were decreased, and left ventricular diastolic pressure was increased. These decreases in myocardial function were closely related to the energy of electrical defibrillation. After a 20-J shock, animals survived for only 5+/-3 hours; after a 10-J shock, animals survived for 15+/-4 hours; and after a 2-J shock, all animals survived for >24 hours.

CONCLUSIONS

The severity of postresuscitation myocardial dysfunction is related, at least in part, to the magnitude of the electrical energy of the delivered shock.

Physical mapping of the 5 Mb D9S196-D9S180 interval harboring the basal cell nevus syndrome gene and localization of six genes in this region

The basal cell nevus syndrome (Gorlin syndrome) is characterized by multiple basal cell carcinomas and diverse developmental defects. The gene responsible for this syndrome has been mapped previously to a 2 cM interval between D9S196 and D9S 180 at 9q22.3, and very recently mutations of a candidate gene in this region--the human homolog of the Drosophila patched gene have been identified. We report here on physical mapping studies integrating a contig of yeast artificial chromosomes and bacterial artificial chromosomes with a long-range map spanning approximately 5 Mb between the recombination-determined flanking markers. Six genes have been mapped to this interval.

Dissociation of TNF-alpha from endotoxin-induced nitric oxide and acute-phase hypotension

We tested the concept that tumor necrosis factor-alpha (TNF-alpha) or platelet-activating factor (PAF) mediated Escherichia coli endotoxin lipopolysaccharide (LPS)-induced upregulation of nitric oxide (NO) and acute-phase hypotension (APH) in the rat. LPS (0.5 mg/kg i.v.) given to rats treated with saline or nonimmune goat-derived gamma-globulin (immunoglobulin G, 22 mg/kg i.m.) produced APH and increased plasma concentrations of TNF-alpha and nitrate and nitrite anions (reactive nitrogen intermediates; RNI) and NO in ex vivo incubates of polymorphonuclear neutrophils (PMN) and inducible NO synthase (iNOS) mRNA in PMN. Pretreatment of rats with a polyclonal TNF-alpha antibody (TNF-Ab, 22 mg/kg i.m.) abolished LPS-mediated increases in plasma TNF-alpha but failed to inhibit APH or the NO system. TNF-alpha (8.2 micrograms/kg i.v.) produced transient hypertension and sustained tachycardia and increased plasma TNF-alpha and PMN iNOS mRNA but not RNI. LPS and TNF-alpha decreased spontaneous and calcimycin (Ca2+ ionophore, 1 microM)- and PAF (1 microM)-mediated increases in head-space NO production by rings of mesenteric artery incubated ex vivo. TNF-Ab abolished all effects of TNF-alpha. PAF (25, 50, and 100 ng/kg) produced APH without increasing plasma TNF-alpha, RNI, or PMN iNOS mRNA. The PAF receptor antagonist BN-50730 (80 micrograms/kg i.v.) abolished PAF-induced APH and attenuated LPS-induced increases in RNI. We conclude that 1) LPS produces parallel but unrelated changes in TNF-alpha and RNI in plasma and PMN during the APH of endotoxemia; and 2) endogenous TNF-alpha is not required for LPS-mediated induction of iNOS mRNA, and PAF mediates LPS-induced APH.

Mutations of the PATCHED gene in several types of sporadic extracutaneous tumors

Patients with basal cell nevus syndrome have a high incidence of multiple basal cell carcinomas, medulloblastomas, and meningiomas. Because somatic PATCHED (PTCH) mutations have been found in sporadic basal cell carcinomas, we have screened for PTCH mutations in several types of sporadic extracutaneous tumors. We found that 2 of 14 sporadic medulloblastomas bear somatic nonsense mutations in one copy of the gene and also deletion of the other copy. In addition, we identified missense mutations in PTCH in two of seven breast carcinomas, one of nine meningiomas, and one colon cancer cell line. No PTCH gene mutations were detected in 10 primary colon carcinomas and eighteen bladder carcinomas.

Buspirone, a 5-hydroxytryptamine1A agonist, is active in cerebellar ataxia. Results of a double-blind drug placebo study in patients with cerebellar cortical atrophy

OBJECTIVE

To establish the antiataxic effect of buspirone hydrochloride, a serotonergic 5-hydroxytryptamine1A (5-HT1A) agonist, in a homogenous group of patients characterized by the same well-defined single condition, cerebellar cortical atrophy.

SETTING

University ataxia research center.

METHODS

Double-blind randomized study of buspirone vs placebo during a 4-month period.

PATIENTS

Nineteen patients met the inclusion criteria; all completed the study. Of these 19 patients, 9 were treated with placebo and 10 were treated with the drug.

MAIN OUTCOME MEASURES

A semiquantitative scale for kinetic and static ("postural") cerebellar functions; quantitative clinical measurements measuring time in standard tests that evaluated stance, speech, writing, and drawing; and posturographic analysis of the sway path and sway area of the center-of-foot pressure. The primary end point was improvement of the posttherapeutic change of one of the semiquantitative ataxic scores. The secondary end points were modification of the changes of quantitative measures--clinical or posturographic.

RESULTS

In intention-to-treat analysis, a significant improvement of the primary end point, ie, the posttherapeutic change of the ataxic kinetic score, was shown. Among secondary end points, the maximum time of standing with feet together also was significantly improved.

CONCLUSIONS

Buspirone is active in cerebellar ataxia of patients with cerebellar atrophy. These results confirm the data suggested by open-label studies with buspirone. However, the effect is partial and not clinically major. These pharmacological results might be due to serotonergic mechanisms and confirm a possible link between cerebellar ataxia and the metabolism of serotonin.

Extracellular matrix regulates ovarian hormone-dependent proliferation of mouse mammary epithelial cells

Mammary stromal cells can modulate steroid hormone responsiveness both in vivo and in vitro. One of the mechanisms by which stromal cells can influence epithelial cell behavior is by modifying the composition of the extracellular matrix (ECM). In this report, we have investigated the effects of five ECM molecules on control of epithelial cell proliferation by estrogen (E2) and progestin (R5020) under serum-free culture conditions. To assess the contribution of mammary gland differentiation in determining epithelial cell interactions with ECM, the behavior of mammary epithelial cells derived from nulliparous and pregnant mice was compared. We report the novel finding that the proliferative responses of mammary epithelial cells to progestin is influenced by specific ECM molecules. However, the primary determinant of hormonal responsiveness is the developmental state of the gland from which the epithelial cells were derived. Nulliparous-derived epithelial cells, proliferated in response to R5020 only on fibronectin (FN) and collagen IV (Col IV). The more highly differentiated, pregnancy-derived epithelial cells were not responsive to E2 or R5020 on any ECM. To determine if steroid hormone receptors were targets of ECM-mediated effects, ER and PR levels were analyzed. In both nulliparous and pregnancy-derived cultures, PR binding levels were maintained at similar levels on all ECMs. However, ER levels were not maintained in nulliparous-derived cultures, and this may have contributed to the lack of a significant response to E2. Alternatively or in addition, E2-induced responses may require additional signals or growth factors that are provided by stromal cells in vivo or by serum supplementation in vitro. These results demonstrate the ECM molecules, fibronectin and collagen IV, can modulate responsiveness of mammary epithelial cells to R5020 in vitro, and may be the mediators of stromal influences on hormone responsiveness in vivo. However, the specific effects of ECM and hormones are also determined by the developmental state of the mammary gland from which the cells are derived. Thus, mammary gland differentiation, ovarian hormones, and ECM composition may act in concert to determine the outcome of hormone treatment on cell proliferation.

Modulation of RNase H activity by modified DNA probes: major groove vs minor groove effects

We have previously prepared ribozyme mimics and chemical nucleases from modified DNA containing pendant bipyridine and terpyridine groups. The ability of these modified DNA probes to support RNase H cleavage of complementary RNA is described. DNA/RNA duplexes were formed using DNA probes designed to deliver metal complexes via either the major groove or the minor groove of the duplex. The duplexes were treated with Escherichia coli RNase H. Modifications in the major groove produced the same RNA cleavage pattern as unmodified DNA probes. However, minor groove substituents inhibited RNA cleavage over a four-base region. Comparison was made with a DNA probe containing a 2'-OMe modification. Our results support enzyme binding in the minor groove of a DNA/RNA duplex. We do not observe cleavage directly across from the modified nucleoside. The RNA cleavage efficiency effected by RNase H and a DNA probe decreases as follows: unmodified DNA > or = C-5 modified DNA >> c2'-modified DNA > C1'-modified DNA. Results with 28-mer RNA substrates roughly parallel those obtained with a 159-mer RNA target. The differences observed between low and high MW RNA substrates can be explained by a much higher enzyme-substrate binding constant for the high MW target.

MNDA dimerizes through a complex motif involving an N-terminal basic region

Human myeloid cell nuclear differentiation antigen (MNDA) is a myelomonocytic lineage-specific protein that influences gene expression through interactions with other nuclear proteins and transcription factors. MNDA also self-associates and chemical cross-linking was used to demonstrate that MNDA forms a dimer. C-terminal and internal deletion mutants were used to identify two regions in the N-terminal half of MNDA essential for self-association. One region contains an imperfect leucine zipper and the second is highly enriched in basic residues. The sequences that are essential for dimerization are separated by a highly basic amphipathic alpha-helical region which was not required for dimerization.

Cingulate cortex synaptic terminal proteins and neural cell adhesion molecule in schizophrenia

The neuronal organization and patterns of afferent innervation are abnormal in the cingulate cortex in schizophrenia, and associated changes in synaptic terminals could be present. A panel of monoclonal antibodies was defined with biochemical and fusion protein studies as detecting syntaxin (antibody SP6), synaptophysin (antibody SP4) and synaptosomal-associated protein-25 (antibody SP12). These antibodies and a polyclonal antibody reactive with neural cell adhesion molecule were used to investigate the cingulate cortex in schizophrenia. Immunocytochemistry indicated that syntaxin immunoreactivity had a considerably wider distribution than synaptophysin. Overall, multivariate analysis indicated increased synaptic terminal protein immunoreactivity in schizophrenia compared to controls (P=0.004). Controlled for age and post mortem interval, syntaxin immunoreactivity was significantly elevated in schizophrenia (P=0.004), and neural cell adhesion molecule immunoreactivity was also elevated (P=0.05). The neural cell adhesion molecule to synaptophysin ratio was increased (P=0.005), possibly indicating the presence of less mature synapses in schizophrenia. Elevated syntaxin immunoreactivity is consistent with increased glutamatergic afferents to the cingulate cortex in schizophrenia, and combined with the neural cell adhesion molecule to synaptophysin ratio results suggests that synaptic function in this region in schizophrenia may be abnormal.