Acute paraplegia in a patient with spinal tophi: a case report

A 28-year-old man with a 5-year history of gouty arthritis suffered from an acute episode of lower back pain. He visited a rehabilitative clinic and received physical therapy following his examination. Weakness and numbness of both lower legs developed rapidly after physical therapy. He was sent to our hospital with complete paralysis of both lower limbs and complete sensory loss below the umbilicus 3 hours after the physical therapy. No peripheral tophi were found. Myelography showed an extrinsic compression of the dura sac at T10. Emergency decompressive laminectomy of T9 to T11 was performed. During the surgery, caseous material was found deposited in the ligamentum flavum and the left T9 to T10 facet joint, with indentation of the dura sac. The pathologic diagnosis was spinal tophi. After surgery, the patient's neurologic function recovered rapidly. It was suspected that inappropriate physical therapy might have aggravated acute inflammation of spinal gout and resulted in a rapid deterioration of neurologic function. Though gout is a chronic medical disease, an acute attack of spinal gout may be disastrous and requires emergency neurosurgical intervention.

Local structure analysis of Ti species stabilized in ion exchangeable layer solids by x-ray absorption spectroscopy

Nano-sized titanium dioxides are incorporated into the interlayer spaces of ion-exchangeable layered perovskites, H(1-x)Ca2(x)La(x)Nb3O10 (x=0.0-0.75), by replacing the interlayer protons with positively charged TiO2 nano-sol particles or basic titanium glycolate complex (titanatrane). Powder X-ray diffraction analysis. UV-Vis absorption spectroscopy, thermogravimetric analysis, and N2 adsorption-desorption isotherm measurements show that quantum sized TiO2 particles are stabilized in between perovskite lattices to form micropores (S(BET) = 37-110 m2/g). X-ray absorption spectroscopy at the Ti K-edge was used for investigating the local environment around Ti atoms constituting the interlayer pillars. According to the XANES spectra, the 'as-pillared' Ti species have the same local environments with those of precursory species, which subsequently converted into TiO2 clusters with rutile and anatase-like local structures when TiO2 nano-sol particles and titanatrane are used as pillaring species. respectively. It is also found that the local environment of TiO2 remains almost constant irrespective of the layer charge density, while the TiO2 pillar content and the microporosity increase with the latter.

Protein nutrition status of adult patients starting chronic ambulatory peritoneal dialysis

Malnutrition is an important determinant of outcome in patients on dialysis. Its cause is multifactorial and its detection is important when patients embark on dialysis. In this study, we used various indices to assess the prevalence of malnutrition as reflected in protein intake, anthropometric effect, and serum protein level. To avoid the effect that dialysis has on malnutrition, we studied 37 patients who had just started continuous ambulatory peritoneal dialysis (CAPD). Of these new patients, 42% had a residual urea clearance below 1.0 mL/min. In 51% of the patients, serum albumin level was below 33 g/L; in 14%, body mass index was below 19; and in 39%, dietary protein intake was below 0.8 g per kilogram of body weight per day. A total of 76% of our patients had at least one of these three indices. In 8% of the patients, lean body mass was below 60%. We conclude that protein malnutrition is a significant problem in our patients starting CAPD. Dialysis-dependent factors were not implicated, as the patients were studied at the start of dialysis. Low intake of protein was a major problem and may have contributed significantly to malnutrition. The low residual urea clearance implied that dialysis was started relatively late and may have contributed to the low protein intake.

Purinoceptor-mediated calcium mobilization and proliferation in HaCaT keratinocytes

To investigate the effect of nucleotides on cytosolic free calcium mobilization and proliferation activity in HaCaT keratinocytes, nucleotides-induced intracellular free calcium concentration ([Ca(2+)](i)) and cell proliferation observed. [Ca(2+)](i) to the extracellular nucleotides was determined using Ca(2+) sensitive indicator, Fura-2/AM with digital video fluorescence imaging microscopy, and cell proliferation was evaluated by counting of cell number. An adenosine 5'-triphosphate (ATP)-induced [Ca(2+)](i) increase was observed from the concentration of 10(-8) M and was more conspicuous at higher concentrations in a concentration-dependent manner. Additionally, other nucleotides such as ADP, UTP, and 2-me-S-ATP also induced a [Ca(2+)](i) increase in a concentration-dependent manner. However, adenosine induced a slight increase of [Ca(2+)](i) only at 10(-3) M. alpha,-methylene-ATP did not evoke any rise in [Ca(2+)](i). The maximal response observed occurred with ATP and UTP at a concentration of 10(-4) M. The ATP-induced transient [Ca(2+)](i) increase was attenuated by the pretreatment with phospholipase C (PLC) inhibitor, U-73122 (10 microM) for 30 min. ATP-induced [Ca(2+)](i) increase and cell proliferation were inhibited by putative P2Y receptor antagonist, suramin (10(-4) M). When the HaCaT cells were stimulated with nucleotides on a concentration of 10(-4) M and cultured for 5 days, the order of effect on cell proliferation was observed to be ATP>UTP>ADP>2-me-S-ATP. Based on these results, we suggest that extracellular ATP stimulate HaCaT keratinocytes proliferation via purinoceptor-mediated [Ca(2+)](i) mobilization

Inhibitory action of water soluble fraction of Terminalia chebula on systemic and local anaphylaxis

We investigated the effects of the water soluble fraction of Terminalia chebula (Combretaceae) (WFTC) on systemic and local anaphylaxis. WFTC administered 1h before compound 48/80 injection inhibited compound 48/80-induced anaphylactic shock 100% with doses of 0.01-1.0 g/kg. When WFTC was administered 5 or 10 min after compound 48/80 injection, the mortality also decreased in a dose-dependent manner. Passive cutaneous anaphylaxis was inhibited by 63.5+/-7.8% by oral administration of WFTC (1.0 g/kg). When WFTC was pretreated at concentrations ranging from 0.005 to 1.0 g/kg, the serum histamine levels were reduced in a dose-dependent manner. WFTC (0.01-1.0 mg/ml) also significantly inhibited histamine release from rat peritoneal mast cells (RPMC) by compound 48/80. However, WFTC (1.0 mg/ml) had a significant increasing effect on anti-dinitrophenyl IgE-induced tumor necrosis factor-alpha production from RPMC. These results indicate that WFTC may possess a strong antianaphylactic action.

Differential regulation of cAMP-mediated gene transcription and ligand selectivity by MC3R and MC4R melanocortin receptors

Melanocortins are known to be involved in the regulation of feeding behavior. These hormones mediate their effects through G-protein-coupled receptors by stimulating adenylate cyclase. In this study we describe the functional response of melanocortin 4 receptor (MC4R) and melanocortin 3 receptor (MC3R) in HEK 293T cells, by using a luciferase reporter gene under the transcriptional control of a cAMP-responsive element (CRE) as a monitor of intracellular cAMP levels and cAMP-regulated gene expression. We were able to show that MC4R and MC3R expressed in the human cell line HEK 293T stimulate transcription induced by stimulation with different analogs of alpha-melanocyte-stimulating hormone (alpha-MSH) at different levels. In our assay of CRE-mediated gene transcription activity, alpha-MSH-ND was the most efficient alpha-MSH analog for MC4R whereas NDP-MSH was the most efficient for MC3R. Changing the His6 residue of alpha-MSH-ND to Gln or Lys markedly decreased CRE-mediated luciferase activity for MC3R compared with MC4R. On analysis by modeling the receptor-ligand complex by NMR, [Gln6]alpha-MSH-ND and [Lys6]alpha-MSH-ND showed different conformational interactions between MC3R and MC4R. Furthermore, the maximum coupling efficiency of MC4R and MC3R to G proteins was different; MC4R showed only 30-50% of the maximum activity induced by MC3R. In total, our results suggest that a differential receptor-ligand interaction is involved and that the relative interactions of MC3R and MC4R with G protein are possibly quantitatively and qualitatively different.

Comparison of diameter and perimeter methods for tumor volume calculation

PURPOSE

Lesion volume is often used as an end point in clinical trials of oncology therapy. We sought to compare the common method of using orthogonal diameters to estimate lesion volume (the diameter method) with a computer-assisted planimetric technique (the perimeter method).

METHODS

Radiologists reviewed 825 magnetic resonance imaging studies from 219 patients with glioblastoma multiforme. Each study had lesion volume independently estimated via the diameter and perimeter methods. Cystic areas were subtracted out or excluded from the outlined lesion. Inter- and intrareader variability was measured by using multiple readings on 48 cases. Where serial studies were available in noncystic cases, a mock response analysis was used.

RESULTS

The perimeter method had a reduced interreader and intrareader variability compared with the diameter method (using SD of differences): intrareader, 1.76 mL v 7.38 mL (P < .001); interreader, 2.51 mL v 9.07 mL (P < .001) for perimeter and diameter results, respectively. Of the 121 noncystic cases, 23 had serial data. In six (26.1%) of those 23, a classification difference occurred when the perimeter method was used versus the diameter method.

CONCLUSION

Variability of measurements was reduced with the computer-assisted perimeter method compared with the diameter method, which suggests that changes in volume can be detected more accurately with the perimeter method. The differences between these techniques seem large enough to have an impact on grading the response to therapy.

Restoration of growth hormone-releasing hormone (GHRH) responsiveness in pituitary GH3 cells by adenovirus-directed expression of the human GHRH receptor

GH-secreting GH3 cells lack GH-releasing hormone (GHRH) receptors. In this study we used adenoviral vectors to transfer the human GHRH receptor to GH3 cells in an effort to restore GHRH responsiveness. A replication-deficient recombinant adenovirus (AdGHRH-R) was designed to allow cytomegalovirus promoter-driven expression of the GHRH receptor messenger RNA. COS-7 cells and GH-producing GH3 cells infected with AdGHRH-R showed GHRH receptor expression on their membranes and exhibited specific GHRH binding. The addition of GHRH to GH3 cells infected with AdGHRH-R increased cAMP levels, induced cAMP response element-binding protein phosphorylation and restored GH secretory responsiveness. GHRH treatment also caused activation of mitogen-activated-protein kinase, induction of c-fos, stimulation of GH promotor activity, and increased cellular proliferation. These findings indicate that adenoviral vectors carrying human GHRH receptor are useful for in vitro studies of GHRH receptor biology and represent a first step toward the development of gene therapy for dwarfism caused by GHRH receptor mutations.

New cationic liposomes for gene transfer into mammalian cells with high efficiency and low toxicity

Novel cationic amphiphiles, based on hydrophobic cholesterol linked to L-lysinamide or L-ornithinamide, were designed and tested as nonviral gene transfer vectors. Each amide form of amino acid was conjugated to cholesterol by a carbamate ester bond to facilitate efficient degradation in animal cells. Cytotoxicity tests were performed for some cell lines. The transfection efficiency of the amphiphiles on different cell lines was evaluated as a liposomal solution in the presence of the fusogenic helper lipid, dioleoyl phosphatidylethanolamine (DOPE). The efficiency was also compared with other generally used gene carriers, such as lipofectin, 3 beta[N-(N'N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) liposome, and polyethylenimine (PEI).

Immunological alterations associated with Plasmodium vivax malaria in South Korea

Various haematological and immunological studies on patients infected with Plasmodium vivax were undertaken, at diagnosis (day 0), after treatment with chloroquine but during primaquine treatment (day 10) and after all treatment (day 59), in South Korea (where there has been a recent and abrupt increase in the incidence of such infection). The main aims were to gain an understanding of the haemto-immunological alterations of this malarial infection, both before and after treatment, and to identify at least one useful marker for the diagnosis and post-treatment monitoring of P. vivax malaria. Thirty-eight patients with P. vivax malaria were compared with 20, apparently healthy controls. At diagnosis, the patients had lymphopenia, marked eosinopenia (the eosinophil count being correlated with the platelet count) and thrombopenia. Cells of most of the lymphocyte subsets investigated [i.e. CD3+, CD8+, CD19+, CD56+, CD3-/CD56+ and CD8+/CD56+ but not CD4+, CD3+/CD56+ or CD25+] were significantly less common among the lymphocytes of patients at diagnosis than among those of the controls. After initiating treatment, the numbers of CD19+ lymphocytes gradually increased (to normal values by day 59), whereas those of CD3+/56+ lymphocytes remained abnormally low throughout the follow-up period. The proportions of lymphocytes identified as CD4+ appeared to be unaffected by treatment. Although serum concentrations of IgE (and, to a lesser extent, IgM) were elevated in the patients at diagnosis, they were subnormal on day 10 post-treatment and normal at the day-59 follow-up. Serum concentrations of IgG and IgA in the patients were always found to be similar to those in the controls. At diagnosis the serum concentrations of complements C3 and C4 were significantly elevated in the patients. C3 remained at the same high concentration during follow-up but the concentration of C4, like that of IgE, was found to be subnormal on day 10 and normal 7 weeks later. The level of parasitaemia (%) was only found to be significantly correlated with haemoglobin concentration. The observation of eosinopenia with elevated IgE and C4 could be a useful indicator of P. vivax malaria, and treatment response could be followed by serial monitoring of serum concentrations of IgE and C4.

Intraventricular hemorrhage caused by lateral ventricular meningioma: a case report

Meningiomas causing intracranial hemorrhage are rare, and hemorrhage from a lateral ventricular meningioma seems to be even rarer. We report a case of trigonal meningioma in a 43-year-old woman who presented with intraventricular hemorrhage, and describe the CT, MRI and angiographic findings.

Perfusion MR imaging in gliomas: comparison with histologic tumor grade

OBJECTIVE

To determine the usefulness of perfusion MR imaging in assessing the histologic grade of cerebral gliomas.

MATERIALS AND METHODS

In order to determine relative cerebral blood volume (rCBV), 22 patients with pathologically proven gliomas (9 glioblastomas, 9 anaplastic gliomas and 4 low-grade gliomas) underwent dynamic contrast-enhanced T2*-weighted and conventional T1- and T2-weighted imaging. rCBV maps were obtained by fitting a gamma-variate function to the contrast material concentration versus time curve. rCBV ratios between tumor and normal white matter (maximum rCBV of tumor / rCBV of contralateral white matter) were calculated and compared between glioblastomas, anaplastic gliomas and low-grade gliomas.

RESULTS

Mean rCBV ratios were 4.90 degrees +/- 1.01 for glioblastomas, 3.97 degrees +/- 0.56 for anaplastic gliomas and 1.75 degrees +/-1.51 for low-grade gliomas, and were thus significantly different; p <.05 between glioblastomas and anaplastic gliomas, p <.05 between anaplastic gliomas and low-grade gliomas, p <.01 between glioblastomas and low-grade gliomas. The rCBV ratio cutoff value which permitted discrimination between high-grade (glioblastomas and anaplastic gliomas) and low-grade gliomas was 2.60, and the sensitivity and specificity of this value were 100% and 75%, respectively.

CONCLUSION

Perfusion MR imaging is a useful and reliable technique for estimating the histologic grade of gliomas.

Toxic amebic colitis coexisting with intestinal tuberculosis

A patient with a fulminant amebic colitis coexisting with intestinal tuberculosis had a sudden onset of crampy abdominal pain, mucoid diarrhea, anorexia, fever and vomiting with signs of positive peritoneal irritation. Fulminant amebic colitis occurring together with intestinal tuberculosis is an uncommon event and may present an interesting patho-etiological relationship. The diagnosis was proven by histopathologic examination of resected specimen. Subtotal colectomy including segmental resection of ileum, about 80 cm in length, followed by exteriorization of both ends, was performed in an emergency basis. Despite all measures, the patient died on the sixth postoperative day. The exact relationship of fulminant amebic colitis and intestinal tuberculosis is speculative but the possibility of a cause and effect relationship exists. Fulminant amebic colitis may readily be confused with other types of inflammatory bowel disease, such as idiopathic ulcerative colitis, Crohn's disease, perforated diverticulitis and appendicitis with perforation. This report draws attention to the resurgence of tuberculosis and amebiasis in Korea, and the need for the high degree of caution required to detect it.

Correlation between acetylation phenotype and genotype in Chinese women

OBJECTIVE

The acetylation polymorphism is a common inherited variation in human drug and carcinogen metabolism. Because N-acetyltransferase (NAT2) is important for the detoxification and/or bioactivation of drugs and carcinogens, this polymorphism has important implications in therapeutics and cancer susceptibility. A high correlation between acetylation phenotype and genotype has been demonstrated in several studies. However, no such data exist for Chinese females. The aim of the present study was to compare acetylation phenotype with NAT2 genotype in a population of primarily non-smoking Chinese females.

METHODS

In the present study, the correlation between N-acetyltransferase activity and NAT2 genotype was evaluated in 103 unrelated Chinese female controls derived from a hospital-based case-control study of lung cancer in Singapore. Acetylation phenotype and genotype were respectively determined using caffeine and an allele-specific polymerase chain reaction (PCR).

RESULTS

The proportions of rapid and slow phenotypes were 78% and 22%, respectively, while the distribution of rapid (heterozygotes and homozygotes combined) and slow acetylator genotypes was 76% and 24%, respectively. The distribution of the various NAT2 genotypes did not differ significantly (chi2 = 1.45, P > 0.05) from that predicted by the Hardy-Weinberg Law. All slow acetylators were accurately predicted (100%), whereas 2 of 80 rapid acetylators were erroneously predicted as slow (2.5%). The overall prediction rate of the PCR-based test for the acetylation phenotype was at 98.1% in our Chinese population.

CONCLUSION

Our results suggest that genotyping with PCR may well become the preferred method for the determination of acetylation polymorphism in epidemiological studies in this Asian population.

Choline acetyltransferase-immunoreactive neurons in the developing rat retina

The development of cholinergic cells in the rat retina has been examined with immunocytochemistry by using antisera against choline acetyltransferase (ChAT). ChAT-immunoreactive (IR) cells were first detected at embryonic day 17 (E17) in the transitional zone between the neuroblastic layer (NBL) and ganglion cell layer (GCL). At E20, ChAT-IR cells are located exclusively in the GCL. At postnatal day 0 (P0), ChAT immunoreactivity appeared for the first time in cells at the distal margin of the NBL. Two prominent bands of labeled processes were first visible at P3, and by P15, these two bands resembled those of the adult retina. In addition, ChAT immunoreactivity appeared transiently in horizontal cells from P5 to P10. The number of ChAT-IR cells increased steadily up to P15. This resulted in a 93.8-fold increase between E17 and P15 (680-63,800 cells). However, after P15, the number declined by 19% from 63,800 cells at P15 to 51,800 in the adult. At all ages, the spatial density of each ChAT-IR cell population in the central retina was higher than in the periphery. In both central and peripheral regions, the peak density of ChAT-IR cells in the GCL was attained at E20. However, in the INL, the peak densities occurred at P3 in the central region and at P5 in the peripheral region. Up to P15, the soma diameter of ChAT-IR cells in the INL and GCL in each region increased continuously, reaching peak values at P15. Our results demonstrate that ChAT immunoreactivity is expressed in early developmental stages in the rat retina, as in other mammals, and that acetylcholine released from ChAT-IR cells may have neurotrophic functions in retinal maturation.

Effects of physostigmine on the pharmacokinetics of intravenous parathion in rats

It was reported that the area under the plasma concentration-time curve from time zero to time infinity (AUC) of parathion was significantly smaller, and the time-averaged total body clearance (Cl) of parathion was significantly faster after intravenous administration of parathion to rats pretreated with dexamethasone than those in control rats. This was supported by significantly faster intrinsic clearance of parathion to form paraoxon in hepatic microsomal fraction of rats pretreated with dexamethasone. The above data suggested that parathion was metabolized to paraoxon by dexamethasone-inducible hepatic cytochrome P450 (CYP) 3A in rats. The purpose of this study is to explain the protective effects of physostigmine against paraoxon toxicity by suppressing CYP3A, and hence, decreasing formation of a toxic metabolite, paraoxon. The pharmacokinetic changes of parathion and paraoxon were investigated after intravenous administration of parathion, 3 mg/kg, to control Sprague-Dawley rats, and the rats pretreated with physostigmine (100 microg/kg, intraperitoneal injection 30 min before parathion administration). After a 1-min intravenous infusion of parathion to rats pretreated with physostigmine, the AUC of parathion (60.4 compared with 73.7 microg min/mL) was significantly greater, Cl of parathion (49.7 compared with 40.7 mL/min/kg) was significantly slower, and amount of paraoxon recovered from liver, mesentery and large intestine at 5 min was smaller than those in control rats. Based on in vitro rat hepatic microsomal studies, physostigmine inhibited significantly the erythromycin N-demethylase activity (1.03 compared with 0.924 nmol/mg protein/min), mainly mediated by hepatic cytochrome P450 3A in rats. The above data suggested that the formation of paraoxon was inhibited in rats pretreated with physostigmine by inhibiting CYP3A.

Dosimetric comparison of pre-planned and or-planned prostate seed brachytherapy

PURPOSE

To compare the dosimetry of the traditional two step procedure (volume study + treatment planning several weeks later) with that of an OR-based single procedure in which these two steps follow one another immediately. Computer generated treatment plans were used in both procedures.

METHODS AND MATERIALS

Several dosimetric parameters relating to target coverage were obtained from dose volume histograms of CT-based evaluation plans developed either 1 or 3 days following seed implantation. A total of 113 patients with early stage (T1C, T2A) prostate cancer were used for this retrospective study.

RESULTS

The fraction of target (prostate) covered by the prescription dose (144 Gy), 90% of the prescription dose (115 Gy), and the dose encompassing 90% of the target in the evaluation plan were all statistically significantly improved for OR-based plans compared to pre-planned cases.

CONCLUSION

In our hands, there is a small but significant improvement in dose coverage of the prostate when the ultrasound volume study and treatment planning are combined into a single procedure.

Molecular cloning and characterization of a protein tyrosine phosphatase enriched in testis, a putative murine homologue of human PTPMEG

Protein tyrosine phosphorylation is regulated by protein tyrosine kinase and protein tyrosine phosphatase activities. These two counteracting proteins are implicated in cell growth and transformation. Using polymerase chain reaction with degenerate primers, we have identified a novel mouse protein tyrosine phosphatase (PTP). This cDNA contains a single open reading frame of the predicted 926 amino acids. Those predicted amino acids showed significant identity with human megakaryocyte protein-tyrosine phosphatase by 91% in nucleotide sequences and 94% in amino acid sequences. We have identified that expression of this PTP is highly enriched in the testis in mouse and human and has been termed here as a 'testis-enriched phosphatase' (TEP). Northern analysis detected two mRNA species of 3.7 and 3.2kb for this PTP in mouse testis and the expression of TEP is regulated during development. The recombinant phosphatase domain possesses protein tyrosine phosphatase activity when expressed in Escherichia coli. Immunohistochemical analysis of the cellular localization of TEP on mouse testis sections showed that this PTP is specifically expressed in spermatocytes and spermatids within seminiferous tubules, suggesting an important role in spermatogenesis.

Antioxidative phenolic compounds from the roots of Rhodiola sachalinensis A. Bor

The acetone extract of the roots of Rhodiola sachalinensis has furnished six phenolic compounds which exhibited significant scavenging effects against DPPH free radical. The structures of these compounds were identified and determined as gallic acid (1), (-)-epigallocatechin 3-O-gallate (2), kaempferol (3), kaempferol 7-O-alpha-L-rhamnopyranoside (4), herbacetin 7-O-alpha-L-rhamnopyranoside, (5) and rhodiolinin (6) by physico-chemical and spectral evidences.

Factors influencing the protein binding of a new phosphodiesterase V inhibitor, DA-8159, using an equilibrium dialysis technique

Various factors influencing the protein binding of DA-8159 to 4% human serum albumin (HSA) were evaluated using an equilibrium dialysis technique at an initial DA-8159 concentration of 5 microg/mL. It took approximately 8 h incubation to reach an equilibrium between 4% HSA and an isotonic phosphate buffer of pH 7.4 containing 3% of dextran ('the buffer') using a Spectra/Por 2 membrane (mol. wt. cut-off: 12,000--14,000) in a water bath shaker kept at 37 degrees C and at a rate of 50 oscillations per min. The extent of binding was dependent on DA-8159 concentrations, HSA concentrations, incubation temperature, buffer pH, and alpha-1-acid glycoprotein (AAG) concentrations. The binding of DA-8159 in heparinized human plasma (93.9%) was significantly higher than in rats (81.4%), rabbits (80.4%), and dogs (82.2%), and this could be due to differences in AAG concentrations in plasma.

Amine group of guanine enhances the binding of norfloxacin antibiotics to DNA

The binding mode of norfloxacin, a quinolone antibacterial agent, in the synthetic polynucleotides poly[d(G-C)2], poly[d(I-C)2] and poly[d(A-T)2] was studied using polarized light spectroscopy, fluorescence spectroscopy and melting profiles. The absorption, circular and linear dichroism properties of norfloxacin are essentially the same for all the complexes, and the angle of electric transition dipole moment I and II of norfloxacin relative to the DNA helix axis is measured as 68-75 degrees for all complexes. These similarities indicate that the binding mode of norfloxacin is similar for all the polynucleotides. The decrease in the linear dichroism (LD) magnitude at 260 nm upon binding norfloxacin, which is strongest for the norfloxacin-poly[d(G-C)2] complex, and the identical melting temperature of poly[d(A-T)2] and poly[d(I-C)2] in the presence and absence of norfloxacin rule out the possibility of classic intercalation and minor groove binding. However, the characteristics of the fluorescence emission spectra of norfloxacin bound to poly[d(A-T)2] and to poly[d(I-C)2] are similar but are different to that of norfloxacin bound to poly[d(G-C)2]. As the amine group of the guanine base protrudes to the minor groove, this result strongly suggests that norfloxacin binds in the minor groove of B-form DNA in a nonclassic manner.

Expression of estrogen receptor-alpha and c-Fos in adrenergic neurons of the female rat during the steroid-induced LH surge

Epinephrine is an important neurotransmitter that is synthesized in relatively few neurons of the medullary regions C1-C3. Epinephrine is involved, among others in the control of most neuroendocrine systems, such as corticotropin releasing hormone-, gonadotropin releasing hormone- and oxytocin/vasopressin-containing neurons as part of complex feedback loop systems that often include interactions with the gonadal or adrenal steroid hormones. In order to determine if the interactions between gonadal steroid hormones with the adrenergic neurons are direct or involve steroid-receptive interneurons that in turn innervate the adrenergic neurons, dual immunohistochemistry was applied to identify if estrogen receptor-alpha (ERalpha) protein was expressed by adrenergic, phenylethanolamine-N-methyl transferase (PNMT)-positive neurons and if estradiol can activate these neurons as determined by the transient expression of the transcription factor c-Fos. The results show that an average of 22% of all PNMT neurons in the C1 region, 38% in C2 and 42% in the C3 region express estrogen receptor-alpha protein with the highest numbers of dual labeled neurons in the central levels of the C1-C3 regions. Overall, the percentages of dual labeled PNMT/ERalpha neurons did not change during the steroid-induced LH surge. In contrast, the percentage of c-Fos expressing PNMT neurons changed significantly during the LH surge. Thus, c-Fos immunoreactivity was highest in all three regions at 1200 h with 69% of the PNMT neurons in C1, 60% in C2 and 79% in C3 co-expressing c-Fos. C-Fos expression was lowest before and after the surge with 39% of the PNMT neurons in the C2 region containing c-Fos at 0800 h, 52% c-Fos-positive PNMT neurons in C1 and 54% in area C3. The results show that many adrenergic neurons are direct targets for estradiol and that most PNMT neurons in the brainstem are activated during the initiation of the steroid-induced LH surge which suggests that epinephrine is one of the triggers that stimulates GnRH release during the surge.

LCC, a cerebroside from Lycium chinense, protects primary cultured rat hepatocytes exposed to galactosamine

Primary cultures of rat hepatocytes exposed to galactosamine (GalN) were used as a screening system to assess whether a new cerebroside, LCC, isolated from the fruits of Lycium chinense, exhibits hepatoprotective activity. Cultured rat hepatocytes injured with GalN routinely release glutamic pyruvic transaminase (GPT) and sorbitol dehydrogenase (SDH) into the culture medium. Treatment of these GalN-injured primary cultures with LCC markedly blocked the release of both GPT and SDH in a dose-dependent manner over concentrations of LCC ranging from 1 microM to 10 microM. To investigate the mechanism of action for the hepatoprotective activity of LCC, the extent of [(3)H]-uridine incorporation into RNA was measured in GalN-injured cultures of rat hepatocytes. [(3)H]-Uridine incorporation was significantly decreased in injured hepatocytes. LCC, however significantly restored the incorporation of [(3)H]-uridine into RNA in a dose-dependent manner over concentrations ranging from 1 microM to 10 microM. LCC also blocked the suppression of RNA synthesis caused by actinomycin D in a dose-dependent manner. These data suggest that LCC may have prominent hepatoprotective activity and that its therapeutic value should be investigated further.

Pharmacogenetics: role in modifying drug dosage regimens

With the advent of new molecular biology and scientific techniques, there is better understanding of genetic polymorphisms in oxidative drug metabolism systems today. These systems are important in pharmacogenetic studies which genotype polymorphic alleles encoding drug metabolising enzymes to enable the individual's drug metabolising phenotype to be found. Once found, the knowledge can be used to tailor drug dosage regimens to an individual to maximise therapeutic efficacy and minimise adverse drug reactions (ADRs). The knowledge could also be used to optimise drug development programmes so that all the subgroups within a target population are adequately represented in clinical trails.

Antioxidant lignans from Machilus thunbergii protect CCl4-injured primary cultures of rat hepatocytes

Eleven lignans (1-11) were isolated from the CH2Cl2 fraction of the bark of Machilus thunbergii Sieb. et Zucc. (Lauraceae). These were identified as (-)-acuminatin (1), (-)-isoguaiacin (2), meso-dihydroguaiaretic acid (3), (+)-galbacin (4), (-)-sesamin (5), (+)-galbelgin (6), machilin A (7), machilin G (8), licarin A (9), and nectandrin A (10) and B (11). Primary cultures of rat hepatocytes were co-incubated for 90 min with the hepatotoxin CCl4 and each of the 11 lignans (50 microM). Hepatoprotective activity was determined by measuring the level of glutamic pyruvic transaminase released into the medium from the primary cultures of rat hepatocytes. (-)-Acuminatin, (-)-isoguaiacin and meso-dihydroguaiaretic acid all significantly reduced the level of glutamic pyruvic transaminase released. Further investigation revealed that these three compounds significantly preserved the levels and the activities of glutathione, superoxide dismutase, glutathione peroxidase and catalase. (-)-Acuminatin, (-)-isoguaiacin and meso-dihydroguaiaretic acid also ameliorated lipid peroxidation as demonstrated by a reduction of malondialdehyde production. These results suggest that (-)-acuminatin, (-)-isoguaiacin and meso-dihydroguaiaretic acid exert diverse hepatoprotective activities, perhaps by serving as potent antioxidants.

Delayed treatment with nicotinamide (Vitamin B(3)) improves neurological outcome and reduces infarct volume after transient focal cerebral ischemia in Wistar rats

BACKGROUND AND PURPOSE

We have previously shown that nicotinamide (NAm) acutely reduces brain infarction induced by permanent middle cerebral artery occlusion (MCAo) in rats. In this study, we investigate whether NAm may protect against ischemia/reperfusion injury by improving sensory and motor behavior as well as brain infarction volumes in a model of transient focal cerebral ischemia.

METHODS

Forty-eight male Wistar rats were used, and transient focal cerebral ischemia was induced by MCAo for 2 hours, followed by reperfusion for either 3 or 7 days. Animals were treated with either intraperitoneal saline or NAm (500 mg/kg) 2 hours after the onset of MCAo (ie, on reperfusion). Sensory and motor behavior scores and body weight were obtained daily, and brain infarction volumes were measured on euthanasia.

RESULTS

Relative to treatment with saline, treatment with NAm (500 mg/kg IP) 2 hours after the onset of transient focal cerebral ischemia in Wistar rats significantly improved sensory (38%, P<0.005) and motor (42%, P<0.05) neurological behavior and weight gain (7%, P<0.05) up to 7 days after MCAo. The cerebral infarct volumes were also reduced 46% (P<0.05) at 3 days and 35% (P=0.09) at 7 days after MCAo.

CONCLUSIONS

NAm is a robust neuroprotective agent against ischemia/reperfusion-induced brain injury in rats, even when administered up to 2 hours after the onset of stroke. Delayed NAm treatment improved both anatomic and functional indices of brain damage. Further studies are needed to clarify whether multiple doses of NAm will improve the extent and duration of this neuroprotective effect and to determine the mechanism(s) of action underlying the neuroprotection observed. Because NAm is already used clinically in large doses and has few side effects, these results are encouraging for the further examination of the possible use of NAm as a therapeutic neuroprotective agent in the clinical treatment of acute ischemic stroke.

Involvement of brassinosteroids in the gravitropic response of primary root of maize

Exogenously applied brassinolide (BL, 10(-9)-10(-5) M) increased gravitropic curvature in maize (Zea mays) primary roots. The BL-enhanced gravitropic curvature was clearly promoted in the presence of indole-3-acetic acid (IAA, 10(-10)-10(-8) M), indicating that BL is interactive with IAA during the gravitropic response. The interactive effect between BL and IAA was completely diminished by treatment of p-chlorophenoxy isobutric acid, an auxin action antagonist. The activation of the gravitropic response by BL in the absence and in the presence of IAA was nullified by application of 2, 3,5-triiodobenzoic acid, a polar auxin transport inhibitor. The data indicate that brassinosteroids (BRs) might be involved in auxin-mediated processes for the gravitropic response. Gas chromotography-selected ion-monitoring analysis revealed that maize primary roots contained approximately 0.3 ng g(-1) fresh weight castasterone as an endogenous BR. Exogenously applied castasterone also increased the gravitropic response of maize roots in an IAA-dependent manner. This study provides the first evidence, to our knowledge, for occurrence and gravitropic activity of BRs in plant roots.

Immunomodulating activity of a polysaccharide isolated from Mori Cortex Radicis

The immunomodulating activity of a polysaccharide isolated from Morus alba (PMA) root bark was examined in murine splenic lymphocytes. PMA enhanced proliferation of splenic lymphocytes in a synergistic manner in the presence of mitogens. However, PMA suppressed primary IgM antibody production from B cells, which was activated with lipopolysaccharide, a polyclonal activator, or immunized with a T-cell dependent antigen sheep red blood cells. Our observations showed that the immunomodulating activity of PMA increased lymphocyte proliferation and that PMA decreased antibody production from B cells, which was distinct from those of other plant-originated polysaccharides.

Stereotactic injection of adenoviral vectors that target gene expression to specific pituitary cell types: implications for gene therapy

OBJECTIVE

Gene therapy is a potentially useful strategy for the treatment of pituitary adenomas or hormone deficiency disorders. We investigated the feasibility of targeting gene expression to specific pituitary cell types in vivo, using a combination of stereotactic injection and adenoviral vectors that carry pituitary-specific promoters.

METHODS

Recombinant adenoviruses containing the human growth hormone promoter (AdGHGal) or the human glycoprotein hormone alpha-subunit promoter (AdalphaGal) were used to drive expression of the beta-galactosidase gene. The expression of beta-galactosidase activity in the pituitary was analyzed after the administration of recombinant adenoviruses via the peripheral vein or the carotid artery, or by stereotactic injection into the rat pituitary. Double-label histology was used to evaluate cell-type expression in the pituitary.

RESULTS

Intravascular injection of AdGHGal or AdalphaGal failed to deliver the marker gene to the pituitary. However, direct stereotactic injection of recombinant adenoviral vectors into the pituitary achieved a high level of transgene expression. In addition, immunohistochemical staining revealed selective expression of the AdGHGal or AdalphaGal transgenes in pituitary cells that normally produce the respective hormones.

CONCLUSION

These findings indicate that adenoviral vectors carrying pituitary gland-specific promoters may be useful for targeted gene therapy of pituitary diseases. However, because of low transduction after peripheral administration, stereotactic injection or local administration of viruses at the time of pituitary surgery is probably required for efficient gene expression.

Adenosine triphosphate-induced heterologous desensitization of endothelin-1- and glutamate-evoked calcium increases in cultured rat cortical astrocytes

In rat cortical astrocytes, we investigated the occurrence of cross-talks between purinoceptor and endothelin (ET) receptor, or glutamate receptor. The treatments of adenosine triphosphate (ATP), ET-1, and glutamate induced the increase of intracellular calcium level in the astrocytes. In repetitive additions of ATP to astrocytes, the second application of ATP exhibited comparable amplitude of calcium response, but the stimulation with ATP completely blocked subsequent ET-1- or glutamate-evoked calcium responses showing complete heterologous desensitization. In contrast, ET-1 and glutamate failed to desensitize the response elicited by ATP. Preincubation with sphingosine, a protein kinase C (PKC) inhibitor, reversed the ATP-induced desensitization of ET-1- and glutamate-evoked calcium responses. Taken together, these results demonstrate the resistance of purinoceptor to homologous desensitization, and unidirectional desensitization between ATP and other receptors such as ET and glutamate receptors, suggesting a dominant role of purinoceptor in modulating calcium signal of astrocytes.

The stem of sinomenium acutum inhibits mast cell-mediated anaphylactic reactions and tumor necrosis factor-alpha production from rat peritoneal mast cells

The aqueous extract of Sinomenium acutum stem (SSAE) (0.1-1000 mg/kg) dose-dependently inhibited systemic anaphylactic reaction induced by compound 48/80 in mice. In particular, SSAE reduced compound 48/80-induced anaphylactic reaction with 50% at the dose of 1000 mg/kg. SSAE (100-1000 mg/kg) also significantly inhibited local anaphylactic reaction activated by anti-dinitrophenyl (DNP) IgE. When mice were pretreated with SSAE at a concentration ranging from 0.1 to 1000 mg/kg, the plasma histamine levels were reduced in a dose-dependent manner. SSAE (1-1000 microg/ml) dose-dependently inhibited histamine release from the rat peritoneal mast cells (RPMCs) activated by compound 48/80 or anti-DNP IgE. In addition, SSAE (0.1 microg/ml) had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha (TNF-alpha) production. These results indicate that SSAE inhibits mast cell-mediated anaphylactic reactions and TNF-alpha production from mast cells.

Divergent effects of putative anxiolytics on stress-induced fos expression in the mesoprefrontal system of the rat

Previously, we reported that R(+)HA-966, a weak partial agonist for the glycine/NMDA receptor, and guanfacine, a noradrenergic alpha2 agonist, have anxiolytic-like actions on the biochemical activation of the mesoprefrontal dopamine neurons and fear-induced behaviors. Here, we examined these two putative anxiolytic agents, both with primary actions independent of GABAergic systems, for their ability to alter stress-induced Fos-like immunoreactivity in the mesoprefrontal cortex and in tyrosine hydroxylase-stained, presumed dopaminergic, neurons in the ventral tegmental area. The benzodiazepine agonist, lorazepam, and partial agonist, bretazenil, were also tested in this footshock paradigm [10 x 0.5 sec, 0.8 mA paired with a 5-sec tone]. In saline-treated rats, footshock resulted in an increase in Fos-li in the prelimbic and infralimbic cortices and tyrosine hydroxylase-labeled cells in the ventral tegmental area. Treatment with lorazepam or bretazenil prevented the stress-induced activation in Fos-li nuclei in all regions of the medial prefrontal cortex and in dopaminergic neurons in the ventral tegmental area. In contrast, the actions of the novel anxiolytic-like agents on stress-induced Fos-li were different than those observed with benzodiazepine agonists. Both putative anxiolytics, R(+)HA-966 and guanfacine, did not reduce, but significantly enhanced the stress-induced Fos-li in the prelimbic region of the medial prefrontal cortex. Additionally, treatment with R(+)HA-966 completely blocked, while guanfacine attenuated, the stress-induced increase in the number of Fos-li, TH-li cells in the ventral tegmental area. These results indicate that the putative anxiolytics, R(+)HA-966 and guanfacine, have actions on the stress-sensitive mesoprefrontal system which appear distinct from those of traditional anxiolytics.

Pharmacogenetics: the molecular genetics of CYP2D6 dependent drug metabolism

INTRODUCTION

Genetic variation of drug metabolising enzymes has been recognised as one of the major causes of the inter-individual variability to drug response. The vast majority of drugs are degraded via a small number of metabolic pathways, mainly by microsomal P-450 enzymes localised in the liver and, to a minor extent, in the small intestine. Of these, CYP3A4 is the isozyme involved in the metabolism of most of the clinically useful drugs (50%). This is followed by CYP2D6 (20%), CYP2C9 and CYP2C19 (15%). In addition, minor pathways are catalysed by CYP2E1, CYP1A2, CYP2A6 and unidentified P-450s. Almost 40% of human P-450 dependent drug metabolism is carried out by genetically polymorphic enzymes. Polymorphisms generated by mutations in the genes for these enzymes cause quantitatively or qualitatively altered enzyme expression or activity through multiple molecular mechanisms. While CYP3A4 genetic polymorphisms are just beginning to be unraveled, extensive studies on the CYP2D6 gene over the last decade have identified at least 53 alleles. Of these, more than 20 of them are known to significantly alter the metabolism of CYP2D6 substrates.

METHODS

This article reviews the information derived from various studies over the past decade and explains the molecular basis of functional differences in CYP2D6 variants, especially with respect to inter-ethnic differences and their clinical implications.

RESULTS

CYP2D6 activity ranges from complete absence to ultra-rapid metabolism. Large inter-individual and inter-ethnic variability exists in the activity of the enzyme, and consequently in the disposition of drugs undergoing oxidative metabolism.

CONCLUSIONS

Pharmacokinetic differences resulting from these polymorphisms show potentially important clinical consequences.

Sauchinone, a lignan from Saururus chinensis, attenuates CCl4-induced toxicity in primary cultures of rat hepatocytes

We used primary cultures of rat hepatocytes injured by the hepatotoxin, carbon tetrachloride (CCl4), as a test system to screen for hepatoprotective compounds from natural products. Sauchinone was isolated from the aerial parts of Saururus chinensis (Saururaceae) by this method. At a concentration of 50 microM, sauchinone significantly reduced the release into the culture medium of glutamic pyruvic transaminase from CCl4-damaged cultures of rat hepatocytes. It has been determined that glutathione, superoxide dismutase and glutathione peroxidase all play important roles in the cellular defense against oxidative stress. Sauchinone appeared to protect primary cultured rat hepatocytes exposed to CCl4 from significant drops in the levels of each of these three specific markers, respectively. Sauchinone also seemed to ameliorate lipid peroxidation as demonstrated by a reduction in the production of the oxidized lipid byproduct, malondialdehyde. These results suggest that sauchinone may exert hepatoprotective activity through antioxidant activity.

Dosimetry of a W-188/Re-188 beta line source for endovascular brachytherapy

PURPOSE

The objective was to determine the dosimetry of a potential endovascular brachytherapy source consisting of a coiled tungsten wire mounted on the distal end of a drive wire and neutron-activated to contain the parent-daughter nuclides tungsten-188 (188W) and rhenium-188 (188Re).

METHODS

A coiled tungsten wire 40 mm in length was neutron-activated by double-neutron capture for 78 hours at 1.9 x 10(15) h/cm2/s to contain 925 MBq (25 mCi) of 188W/188Re in equilibrium. The dose-fall off from this source was determined using three independent methods: (a) Thermoluminescence dosimetry with small LiF-100 rods, (b) Gafchromic film dosimetry, and (c) Bang gel dosimetry. In addition, a Monte Carlo simulation was performed to compute the beta-dose.

RESULTS

Each of the three measurement methods recorded similar values for the dose fall-off within the distances useful for endovascular brachytherapy. The Monte Carlo calculations closely approximated the measured results in the treatment range between 1 and 3 mm and may thus be useful for evaluating changing geometries in the development of catheters and source setups. A 2 min restenosis treatment delivering 20 Gy at a radius of 2 mm would require a source of 1384.8 MBq/cm (37.4 mCi/cm).

CONCLUSIONS

The dose distribution from a 188W/188Re source is similar to that of a 90Y-source. An added advantage of the 188W/188Re source is that it can be used for at least two months and still provides fast treatment times because of the parent isotope's half-life of 69 days. The additional gamma emission from the source is too small to impose a serious radiological hazard. The high atomic number and density of the source material allows direct fluoroscopic imaging without additional markers.

The role of family: perceptions of children with sickle cell

The purpose of this study was to determine the perceptions of the quality of family relationships between children with sickle cell disease and their non-diseased siblings. In this study, 28 subjects were interviewed in their homes. The quality of family relations was assessed utilizing the Family Environment Scale (Moos & Moos, 1981). There was no significant difference in cohesion, expressiveness, conflict, or organization. Control was higher for boys than girls. Implications for family nursing practice are presented.

Immunohistochemical examination of the INK4 and Cip inhibitors in the rat neonatal cerebellum: cellular localization and the impact of protein calorie malnutrition

Expression of the cyclin-dependent kinase inhibitors (CKIs) has been linked to the inhibition of cellular proliferation and the induction of differentiation. Based on structure function analysis, two distinct families of CDKIs, the INK4 and the Cip/Kip family have been identified. The INK4 family member p16(Ink4), and the Cip/Kip protein p27(Kip1) have been implicated in normal development of the CNS and cerebellum. Recent studies have suggested a functional inter-dependence between the CKI and the abundance of cyclin D1 in orchestrating growth factor-induced cellular proliferation. The neonatal rat cerebellum undergoes proliferative growth and differentiation, localized to distinct topographical regions and cell types. The cell type and the temporal profile of CKI expression during postnatal cerebellar development had not been described. The current studies determined the specific cerebellar cell types in which the CKIs were expressed during post natal development by co-staining for cell-type specific markers. p16(Ink4a) and p27(Kip1) immunostaining was identified in both neurons and glial cells, increasing progressively between postnatal days 6 to 13 into adulthood. By contrast, neuronal and glial cell p21(Cip1) staining was prominent at days 6-11 and decreased thereafter. Cyclin D1 was expressed in the proliferating external granular cells, with occassional staining in the molecular, and internal granular layers. Dual immunostaining demonstrated cyclin D1 within cells expressing CKI (p16(Ink4a), p21(Cip1),p27(Kip1)). Cerebellar cellular growth arrest, induced by protein-calorie malnutrition, inhibited cyclin D1 protein levels without affecting CKI immunostaining suggesting CKI do not mediate the developmental arrest. These results demonstrate that the CKIs are induced by differentiation cues in specific cell types with distinct kinetics in the developing cerebellum in vivo.

12-O-tetradecanoyl phorbol 13-acetate, protein kinase C (PKC) activator, protects human leukemia HL-60 cells from taxol-induced apoptosis: possible role for extracellular signal-regulated kinase

The purpose of this study was to evaluate whether the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK) signaling pathway contributes to 12-O-tertadecanoyl phorbol 13-acetate (TPA)-mediated protection from taxol-induced apoptosis of human leukemia HL-60 cells. Treatment of cells with taxol for 12 h resulted in apoptosis of HL-60 cells. TPA was protective against taxol-induced apoptosis and this anti-apoptotic effect was reversible when TPA was used in conjunction with staurosporine and H-7, PKC inhibitors, suggesting that TPA may protect HL-60 cells against taxol-induced apoptosis via the PKC-dependent pathway. Since TPA stimulates MEK signal transduction pathway in HL-60 cells, we postulated that MEK pathway may be playing a role in the ability of TPA to inhibit taxol-induced apoptosis. PD098059, a specific MEK kinase inhibitor, abolished the ability of TPA to inhibit taxol-induced apoptosis. These results suggest that activation of PKC in HL-60 cells confers protection against taxol-induced apoptosis and that MEK mediates anti-apoptotic signaling of PKC.

Functional MR imaging of working memory in the human brain

OBJECTIVE

In order to investigate the functional brain anatomy associated with verbal and visual working memory, functional magnetic resonance imaging was performed.

MATERIALS AND METHODS

In ten normal right handed subjects, functional MR images were obtained using a 1.5-T MR scanner and the EPI BOLD technique. An item recognition task was used for stimulation, and during the activation period of the verbal working memory task, consonant letters were used. During the activation period of the visual working memory task, symbols or diagrams were employed instead of letters. For the post-processing of images, the SPM program was used, with the threshold of significance set at p <.001. We assessed activated brain areas during the two stimulation tasks and compared the activated regions between the two tasks.

RESULTS

The prefrontal cortex and secondary visual cortex were activated bilaterally by both verbal and visual working memory tasks, and the patterns of activated signals were similar in both tasks. The superior parietal cortex was also activated by both tasks, with lateralization to the left in the verbal task, and bilaterally without lateralization in the visual task. The inferior frontal cortex, inferior parietal cortex and temporal gyrus were activated exclusively by the verbal working memory task, predominantly in the left hemisphere.

CONCLUSION

The prefrontal cortex is activated by two stimulation tasks, and this is related to the function of the central executive. The language areas activated by the verbal working memory task may be a function of the phonological loop. Bilateral prefrontal and superior parietal cortices activated by the visual working memory task may be related to the visual maintenance of objects, representing visual working memory.

A developmentally regulated catalase required for proper differentiation and osmoprotection of Streptomyces coelicolor

Streptomyces coelicolor produces at least three catalases, the expression of which varies under different conditions. We characterized a gene (catB) for developmentally controlled catalase of 779 amino acids (83408 Da), homologous to KatE of Escherichia coli and Bacillus subtilis. Expression of the catB gene increased at the stationary phase in liquid culture and after the onset of differentiation on solid culture. It was also increased by osmotic treatments. Transcription was initiated from a promoter (catBp), whose sequence (ATGCCTCG-N13-GGGTAC) resembled promoters recognized by sigmaB of B. subtilis. CatB protein underwent proteolytic cleavage of its N-terminal 95 amino acids and was secreted to the medium when cells sporulated. Disruption of the catB gene caused impairment in the formation of aerial mycelium and reduction in the synthesis of undecylprodigiosin. On the contrary, hyperproduction of actinorhodin was observed in accordance with the increase in actII-ORF4 transcription. In addition, catB mutant became hypersensitive to osmotic stresses. These results suggest that regulated synthesis of CatB protein is necessary to ensure proper differentiation as well as to protect S. coelicolor cells against osmotic stresses.

Use of the Cre/lox recombination system to develop a non-lethal knock-in murine model for osteogenesis imperfecta with an alpha1(I) G349C substitution. Variability in phenotype in BrtlIV mice

We utilized the Cre/lox recombination system to develop the first knock-in murine model for osteogenesis imperfecta (OI). The moderately severe OI phenotype was obtained from an alpha1(I) Gly(349) --> Cys substitution in type I collagen, reproducing the mutation in a type IV OI child. We introduced four single nucleotide (nt) changes into murine col1a1 exon 23: the disease causing G-->T transversion (nt 1546), an adjacent G-->T change (nt 1551) to generate a GUC ribozyme cleavage site, and two transversions (nt 1567 C-->A and nt 1569 C-->G) to cause a Leu --> Met substitution. We also introduced a 3.2-kilobase pair transcription/translation stop cassette in intron 22, flanked by directly repeating lox recombination sites. After homologous recombination in ES cells, two male chimeras were obtained. Chimeras were mated with transgenic females expressing Cre recombinase to remove the stop cassette from a portion of the progeny's cells. To generate mice with full expression of the Gly(349) --> Cys mutation, these offspring were then mated with wild-type females. Skeletal staining and bone histology of the F2 revealed a classical OI phenotype with deformity, fragility, osteoporosis and disorganized trabecular structure. We designate these mice BrtlIV (Brittle IV). BrtlIV mice have phenotypic variability ranging from perinatal lethality to long term survival with reproductive success. The phenotypic variability is not associated with differences in expression levels of the mutant allele in total RNA derived from tissue extracts. Expression of the mutant protein is also equivalent in different phenotypes. Thus, these mice are an excellent model for delineation of the modifying factors postulated to affect human OI phenotypes. In addition, we generated knock-in mice carrying an "intronic" inclusion by mating chimeras with wild-type females. Alternative splicing involving the stop cassette results in retention of non-collagenous sequences. These mice reproduce the lethal phenotype of similar human mutations and are designated BrtlII.

Isolated cleft palate in mice with a targeted mutation of the LIM homeobox gene lhx8

Formation of the mammalian secondary palate is a highly regulated and complex process whose impairment often results in cleft palate, a common birth defect in both humans and animals. Loss-of-function analysis has linked a growing number of genes to this process. Here we report that Lhx8, a recently identified LIM homeobox gene, is expressed in the mesenchyme of the mouse palatal structures throughout their development. To test the function of Lhx8 in vivo, we generated a mutant mouse with a targeted deletion of the Lhx8 gene. Our analysis of the mutant animals revealed a crucial role for Lhx8 in palatogenesis. In Lhx8 homozygous mutant embryos, the bilateral primordial palatal shelves formed and elevated normally, but they often failed to make contact and to fuse properly, resulting in a cleft secondary palate. Because development of other craniofacial structures appeared normal, the impaired palatal formation in Lhx8-mutant mice was most likely caused by an intrinsic primary defect in the mesenchyme of the palatal shelves. The cleft palate phenotype observed in Lhx8-mutant mice suggests that Lhx8 is a candidate gene for the isolated nonsyndromic form of cleft palate in humans.

Mechanism of silica- and titanium dioxide-induced cytotoxicity in alveolar macrophages

Particles can cause cytotoxicity in pulmonary alveolar macrophages (AM). Several mechanisms to explain this cytotoxicity have been suggested. However, the exact mechanism of particle-induced cytotoxicity in AM remains to be established. Silica and TiO2 produced a concentration-dependent cytotoxicity as evidenced by loss of cell viability and fall in ATP levels. While silica induced a greater cytotoxicity, TiO2 produced a higher reduction in ATP levels. Silica increased the release of LDH, but TiO2 did not affect enzymatic release. TiO2 suppressed succinate-triggered oxygen consumption, whereas silica did not markedly change the effect of succinate on oxygen consumption. Polyinosinic acid (PI), a ligand of the scavenger receptor, inhibited the TiO2-induced fall in ATP content, but could not prevent the effect of silica on cellular ATP content. Data suggest that silica and TiO2 can induce cytotoxicity in AM, probably through different mechanisms.

Early alterations in cerebral hemodynamics, brain metabolism, and blood-brain barrier permeability in experimental intracerebral hemorrhage

OBJECT

The authors sought to ascertain the nature of the hemodynamic and metabolic derangement underlying acute pathophysiological events that occur after intracerebral hemorrhage (ICH).

METHODS

Cerebral perfusion pressure (CPP), flow velocity (FV) of the middle cerebral artery, and the arteriovenous contents of oxygen and lactate were investigated in 24 dogs subjected to sham operations (Group A, four animals) or intracerebral injections of 3 ml (Group B, 11 animals) or 5 ml (Group C, nine animals) autologous arterial blood. Twelve additional dogs received intravenous injections of 2% Evans blue or trypan blue dye to evaluate blood-brain barrier (BBB) changes. Within 1 hour, animals with ICH exhibited a rise in FV associated with significant reductions (p<0.05) in CPP and the arteriovenous content difference (AVDO2). In Group C animals significant increases in lactate concentration were found in arterial and superior sagittal sinus (SSS) samples compared with those in the other two groups (p<0.05). Additionally, perihematomal dye extravasation was observed in animals subjected to ICH and trypan blue dye injections, with profound and mild leakages in Group C and Group B animals, respectively, but not in Group A and Evans blue dye-injected animals. During the subsequent 4 hours, the FV and AVDO2 returned to normal in Group B animals, indicating a balanced cerebral metabolic rate for oxygen (CMRO2) compared with a deranged CMRO2 in Group C animals due to their lowered FV and AVDO2. However, no coupling increase in brain lactate clearance in Group C animals accounted for either the early lactate elevation in SSS or the decrease in CMRO2.

CONCLUSIONS

Profound reductions in CPP and brain oxygenation after ICH may rapidly exhaust hemodynamic compensation and, thus, impede cerebral homeostasis; however, these reductions only modestly enhance anaerobic glycolysis. Furthermore, the data suggest that a selective increase in permeability, rather than anatomical disruption, of the BBB is involved in the acute pathophysiological events that occur after ICH, which may provide a possible gateway for systemic arterial lactate entering the SSS.

Immunocytological localization of dopamine in the guinea pig retina

We examined dopaminergic neurons in the guinea pig retina; antisera against tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT) and an antiserum against gamma-aminobutyric acid (GABA) were used. In the present study, two types of amacrine cells were labeled with an anti-TH antiserum. However, no DBH and PNMT immunoreactivities were seen. The type 1 cell had a larger-sized soma located in the inner nuclear layer with processes ramifying mainly in stratum 1 of the inner plexiform layer (IPL). The type 2 cell had a smaller-sized soma and processes branching in stratum 3 of the IPL. The mean densities were 56.4 +/- 11.5/mm2 for the type 1 cell and 166.6 +/- 30.3/mm2 for the type 2 cell. Double immunocytochemistry using an antiserum against GABA revealed that while none of the type 1 cells showed GABA immunoreactivity, all of the type 2 cells displayed GABA immunoreactivity. Our results suggest that, in the guinea pig retina, the type 1 amacrine cells are pure dopaminergic and the type 2 cells are dopaminergic elements that use GABA as their second transmitter.

Ileo-rectal fistula complicating advanced ovarian carcinoma

Fistula between the bowels and an ovarian carcinoma is recognized but rare complication. Internal malignant fistula of the gastrointestinal tract involving two or more loops of different segments of the bowel and genitourinary structure are rare. The colon is frequently one of the participating loops. In reviewing the literature, however, we were unable to find a previous report of ileo-rectal fistula as a complication of an ovarian carcinoma. A case report and review of the English medical literature are presented with emphasis on the cause, clinical presentation, and management of advanced ovarian cancer with ileo-rectal involvement.

Mexiletine and magnesium independently, but not combined, protect against permanent focal cerebral ischemia in Wistar rats

The neuroprotective effect of mexiletine (Mex), a potent Na(+) channel blocker which decreases neuronal energy demands and prevents energy depletion during ischemia, was evaluated in Wistar rats subjected to permanent middle cerebral artery (MCA) occlusion. Postmortem infarct volumes were determined by quantitative image analysis of triphenyltetrazolium (TTC)-stained brain sections. Pretreatment with Mex resulted in a significant infarct volume reduction when administered intraperitoneally, either at the dosage of 50 or 60 mg/kg, 1 hr before MCA occlusion (P < 0.05). Delayed treatment with Mex (50 mg/kg) also had neuroprotective effects when given at 0.5 hr (< 0.05), but not 2-4 hr, after MCA occlusion. Intraarterial administration of MgSO(4) (90 mg/kg), in combination with Mex at 60 mg/kg, showed no additive neuroprotective effect, although each agent independently reduced the MCA occlusion-induced infarction volume (P < 0.05). Our results indicate that a single, acute administration of Mex is neuroprotective against permanent focal cerebral ischemia, but perhaps chronic administration is needed to establish a more effective therapeutic window beyond 0.5 hr. Moreover, the present in vivo data do not favor a combined use of Mg(2+) with Mex for limiting ischemic injury in the brain, since these agents caused cardiopulmonary suppression, which may have led to the loss of the neuroprotective effect of each agent independently.

The application of transcranial Doppler sonography in patients with chronic subdural haematoma

The aim of this study was to evaluate the haemodynamic changes of the middle cerebral artery (MCA) and their clinical significance before and after surgical aspiration in patients with chronic subdural haematoma (CSDH). Nineteen patients with CSDH (17 unilateral and 2 bilateral) received transcranial Doppler sonography (TCD) examinations for cerebral blood flow velocity (CBFv) of the MCA prior to and 5 days after neurosurgical treatment. A total of 21 lesion and 10 non-lesion hemispheres were included. Cranial computerized tomography (CT) and clinical assessments were performed before and 3 months following surgery. The preoperative TCD study revealed that the lesion hemisphere had a modest decrease in CBFv in the MCA as compared to the non-lesion hemisphere. Postoperatively, the CBFv significantly improved in the lesion hemisphere, but not in the non-lesion hemisphere, compared to the preoperative data (P < 0.005). The improvement in CBFv showed no significant correlation with brain shift and haematoma volume of the initial cranial CT. Additionally, two patients, who were proved to have a postoperative complication of subdural pneumocephalus, failed to attend follow-up examinations of TCD. Our results support TCD as an alternative follow-up examination for patients with CSDH, although it may not be sensitive enough as a preoperative screening tool. Postoperatively, improvements in the CBFv of the lesion hemisphere are characteristic. An unexplained difficulty of accessing cerebral basal arteries in follow-up TCD examinations should suggest pneumocephalus in the primary differential diagnosis.

Inhibition of immediate-type allergic reaction by Rosa davurica Pall. in a murine model

We studied the effect of Rosa davurica Pall. (Rosaceae) fruits (RdF) on immediate-type allergic reactions. RdF completely inhibited compound 48/80-induced systemic anaphylactic shock at the dose of 1 g/kg. When RdF was given as pretreatment, at concentrations ranging from 0.0001 to 1 g/kg, the serum histamine levels induced by compound 48/80 were reduced in a dose-dependent manner. RdF inhibited the passive cutaneous anaphylaxis activated by anti-dinitrophenyl (DNP) IgE antibody dose dependently. RdF also inhibited the histamine release induced by compound 48/80 or anti-DNP IgE from the rat peritoneal mast cells (RPMC). Moreover, RdF had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-alpha production from RPMC. These results indicate that RdF may contain compounds with actions that inhibit mast cell degranulation in the rat.

Parallel phase I studies of daunorubicin given with cytarabine and etoposide with or without the multidrug resistance modulator PSC-833 in previously untreated patients 60 years of age or older with acute myeloid leukemia: results of cancer and leukemia group B study 9420

PURPOSE

The Cancer and Leukemia Group B conducted parallel phase I trials of cytarabine, daunorubicin, and etoposide (ADE) with or without PSC-833 (P), a modulator of p-glycoprotein-mediated multidrug resistance.

PATIENTS AND METHODS

One hundred ten newly diagnosed patients > or = 60 years of age with de novo acute myeloid leukemia (AML) were treated. All patients received cytarabine by continuous infusion for 7 days at 100 mg/m(2)/d. The starting dose of daunorubicin was 30 mg/m(2)/d for 3 days. Etoposide was administered at a dose of 100 mg/m(2)/d for 3 days, except in the last cohort administered ADEP, who received 60 mg/m(2). PSC-833 was given intravenously with a loading dose of 1.5 mg/kg over 2 hours and a simultaneous continuous infusion of 10 mg/kg/d continued until 24 hours after the last dose of daunorubicin or etoposide.

RESULTS

There was no toxicity attributed to the PSC-833. Dose-limiting toxicity was primarily gastrointestinal (diarrhea, mucositis in the ADEP group). The estimated maximum-tolerated doses, calculated using a logistic regression model, were daunorubicin 40 mg/m(2)/d for 3 days with etoposide 60 mg/m(2) for 3 days in the ADEP group and daunorubicin 60 mg/m(2)/d for 3 days and etoposide 100 mg/m(2)/d for 3 days in the ADE group. Twenty-one (48%) of 44 patients achieved complete remission with ADE, compared with 29 (44%) of 66 patients treated with ADEP.

CONCLUSION

It is necessary to decrease the doses of daunorubicin and etoposide when they are administered with PSC-833, presumably because of the effect of the modulator on the pharmacokinetics of these agents. A phase III trial comparing the regimens derived from this phase I trial has recently begun.