Defects in the generation of IFN-gamma are overcome to control infection with Leishmania donovani in CC chemokine receptor (CCR) 5-, macrophage inflammatory protein-1 alpha-, or CCR2-deficient mice

We investigated the immune responses in mice lacking CCR2, CCR5, or macrophage inflammatory protein-1 alpha (MIP-1 alpha), a ligand for CCR5, in two situations: following T cell stimulation or after challenge with Leishmania donovani, an intracellular microbe whose control is dependent on a Th1 immune response. Mice deficient in CCR5, MIP-1 alpha, or CCR2 had reduced IFN-gamma responses following ligation of the TCR. Reduced IFN-gamma responses following PMA and ionomycin were also observed in CD8+ T cells of CCR5-/- and CCR2-/- mice. During the early phases of infection, all three knockout mice had low Ag-specific IFN-gamma responses. However, this reduced IFN-gamma response was overcome during a state of persistent Ag stimulation (chronic infection), and was not associated with an adverse parasitologic outcome in any of the gene-targeted mouse strains. To the contrary, during the late phase of infection, an exaggerated Ag-specific IFN-gamma response was evident in CCR5-/- and MIP-1 alpha-/- mice, and this correlated with an enhanced control of parasite replication. Although granuloma formation was abnormal in each of the knockout mice, there was no correlation between the number or architecture of the granulomas and parasite burden. Collectively, these findings indicate an important role for CCR5, MIP-1 alpha, and CCR2 in granulomatous inflammation, and that CCR5 and MIP-1 alpha, possibly acting through CCR5, might play a deleterious role in the outcome of chronic L. donovani infection. Our data also suggest that there might be cross-talk between TCR and chemokine receptor signaling pathways.

Determination of free calcium in guinea-pig cochlea perilymph by capillary electrophoresis with direct injection

At present, the tinnitus mechanism is still not clear. Our experiments demonstrated that the concentration of free calcium in cochlea perilymph of tinnitus model guinea-pigs is lower than that in normal guinea-pigs. However, the volume of cochlea perilymph is so small that only 5-10 microL of sample can be obtained from each animal. We describe the application of CE to the detection of free calcium in guinea-pig cochlea perilymph. Direct injection was employed in this study. The separation was carried out at 10 kV. The capillary temperature was maintained at 20 degrees C, and indirect UV detection at 214 nm was employed. The samples were vacuum injected for 3 s. The run buffer was 0.005 mol/L imidazole with a pH of 4.30-4.50. The concentration of free calcium in the normal group was found to be in accordance with the reference data. The method has been applied to research on the tinnitus mechanism and for medical treatment.

Neuroprotective effect of high-dose albumin therapy against global ischemic brain injury in rats

The purpose of this study was to determine whether treatment with high-dose human serum albumin (HSA) would offer protection in a model of high-grade transient forebrain ischemia. Twenty-six fasted Wistar rats underwent bilateral common carotid artery occlusion and severe hypotension (50 mmHg) for 10 min. The agent (25% HSA) or vehicle (0.9% NaCl) was administered i.v. 5 min after termination of ischemia. HSA-treated rats showed significantly improved neurological deficits throughout a 7-day survival period. Histologically, HSA-treated rats showed 2.4- to 5.3-fold increases in numbers of surviving CA1 hippocampal pyramidal neurons compared to saline-treated animals. These results document that high-dose albumin therapy instituted 5 min after global ischemia significantly improves neurological score and reduces histological damage.

Dendritic cell (DC)-based anti-infective strategies: DCs engineered to secrete IL-12 are a potent vaccine in a murine model of an intracellular infection

Infections with intracellular pathogens such as Leishmania donovani and Mycobacterium tuberculosis pose serious health problems worldwide. Effective vaccines for these pathogens are not available. Furthermore, despite optimal therapy, disease progression is often seen with several intracellular infections. For these reasons, we initiated studies to develop novel anti-infective vaccine and treatment strategies that couple the potent Ag-presenting capacity of dendritic cells (DC) with paracrine delivery of potent anti-infective cytokines such as IL-12 to local immune response sites. We tested this strategy in a murine model of visceral leishmaniasis. Adoptive transfer of DCs pulsed ex vivo with soluble L. donovani Ags (SLDA) to naive mice induced the Ag-specific production of IFN-gamma, and increased the percentage of activation markers on spleen lymphocytes. SLDA-pulsed DCs engineered by retroviral gene transfer techniques to secrete high levels of biologically active murine IL-12 augmented this immune response further. In several different vaccination and immunotherapy protocols, compared with sham-treated mice, animals receiving SLDA-pulsed DCs either before or following infection had 1-3 log lower parasite burdens, and this protection was associated with a pronounced enhancement in the parasite-specific IFN-gamma response. The augmentation of this protection by IL-12-engineered DCs was striking. First, live parasites were not detected in the liver of mice vaccinated with IL-12-transduced, SLDA-pulsed DCs. Second, this parasitological response was associated with a nearly normal liver histology. In contrast, parasites and granulomas were found in mice vaccinated with SLDA-pulsed, nontransduced DCs. Collectively, these studies provide the rationale for the development of potent DC-based immunotherapies.

Detection of bone marrow micrometastasis

The detection of metastasizing single tumor cells has so far been difficult. Using a monoclonal antibody (MAb A45-B/B3) recognizing human cytokeratin, we identified immunocytochemically single tumor cells and micrometastases in patients (n = 24) with nonsmall cell lung cancer at the time of surgery of the primary tumor. The cytokeratin-positive cells (1-14/5 x 10(5) cells) in the bone marrow samples of 9 (9/24) patients were found. We also found a garland-like cluster, which consists of seven cancer cells and two closely connected tumor cells from one bone marrow sample. These results indicate that this technique can be used as a early diagnostic technique of bone marrow micrometastasis in the patient with the nonsmall cell lung cancer.

Sudden death in a rat subarachnoid hemorrhage model

The pathogenesis of sudden death during subarachnoid hemorrhage (SAH) still remains to be elucidated. A new rat common carotid artery-prechiasmal extracorporeal shunt model was designed to study the effect of different severities of SAH on intracranial pressure (ICP), regional cerebral blood flow (rCBF), and mortality. Different severities of SAH were induced by controlling the bleeding period (from 30 to 90 sec) and number of bleedings (one or three times). SAH caused a dramatic increase in ICP and immediate depression of rCBF, which recovered slowly to a certain extent. ICP increased sharply within the first 30 seconds and reached a plateau concomitant with nearly zero rCBF, which suggested the occurrence of cerebral circulation arrest. Bleeding of more than 60 seconds and increased ICP over 80 mmHg were directly correlated with the mortality. Respiratory arrest was the first sign of death, immediately followed by cardiac depression resulting in sudden death. This model combines arterial bleeding with systemic blood pressure and controlled bleeding time to simulate the acute period of SAH.

[Clinical and experimental study on treatment of Helicobacter pylori infected gastritis by xialian yiyou capsule]

OBJECTIVE

To observe the therapeutic effect of Xialian Yiyou Capsule (XLYYC) on helicobacter pylori (HP) infected gastritis to develop the serial Chinese classical recipe.

METHODS

HP infected patients were divided into two groups, 136 patients in the XLYYC group treated with XLYYC and 90 patients in the control group treated with Lizhu Dele Capsule, for 4 weeks as one therapeutic course, the clinical therapeutic effect was observed, and corresponding animal experiments were done.

RESULTS

Clinical effect of the XLYYC group was better than that of the control group in improving clinical symptoms, relieving inflammation of gastric mucosa and eliminating HP (P < 0.05, P < 0.01). Results of animal experiment showed that XLYYC was superior than the control significantly in anti-inflammation, analgesia, stomach emptying and curing gastric ulcer model (P < 0.05, P < 0.01). Without any adverse reaction has been found in acute toxicologic study.

CONCLUSION

The therapeutic effect of XLYYC in treating HP infected gastritis was definite and safe, non-toxic.

The acute ischemic penumbra: topography, life span, and therapeutic response

Recent advances in computerized image-averaging, used in conjunction with refined techniques for engendering highly reproducible rodent models of focal ischemia, now make it possible to derive topographically precise, quantitative descriptors of the ischemic penumbra--its localization, lifespan, metabolic and hemodynamic features, and responses to therapy. Physiologically monitored normothermic rats received 2-h middle cerebral artery occlusion (MCAo) by means of a poly-L-lysine-coated intraluminal suture. In matched groups, local cerebral blood flow (LCBF) or glucose utilization (LCMRglc) were measured autoradiographically at either 2-h MCAo or at 1-h recirculation and were correlated on a pixel-by-pixel basis with histopathological infarction after 3-day survival. A large, consistent ischemic penumbra (defined as LCBF 20-40% of control) surrounded the core (0-20% of control). Penumbral LCMRglc at 2-h MCAo was near-normal, and its metabolism/flow ratio was elevated 4-fold above normal. By 1-h recirculation, however, LCMRglc throughout the prior zone of ischemia was depressed. Infarctive histopathology was precisely determined by the antecedent LCBF decrement during ischemia: 70% and 89% of infarcted pixels had antecedent LCBF values below the upper-core and upper-penumbral ranges, respectively, at 2-h MCAo. High-dose albumin therapy at the onset of recirculation dramatically attenuated cortical infarction and brain edema and appeared, by LCBF analysis at 1-h recirculation, to increase postischemic LCBF primarily in the former penumbra.

Irradiation of rat mesangial cells alters the expression of gene products associated with the development of renal fibrosis

To determine the ability of radiation to modulate mesangial cell expression of various molecules involved in promoting extracellular matrix (ECM) accumulation [fibronectin, plasminogen activator-inhibitor 1 (Pai1), and tissue inhibitor of metalloproteinase-2 (Timp2)] and degradation (Tgfb, plasminogen activators u-PA or t-PA, matrix metalloproteinases Mmp2 and Mmp9), primary cultures of rat mesangial cells (passage number 6-11) were placed in serum-free medium 24 h prior to irradiation with single doses of 0.5-20 Gy (137)Cs gamma rays. After irradiation, cells were maintained in serum-free medium for a further 48 h. Irradiation of quiescent mesangial cells resulted in significant (P < 0.05) time- and dose-dependent increases in Fn and Pai1 mRNA and/or immunoreactive protein. Despite an increase in Tgfb1 mRNA, there was little evidence for an increase in total Tgfb protein. Indeed, active levels remained unaltered after irradiation. Irradiation led to differential changes in MMP expression; active Mmp2 levels increased, while Mmp9 levels appeared unaltered. In addition, secretion of plasminogen activators into the medium was unchanged after irradiation, while secretion of Timp2 increased. We conclude that irradiating mesangial cells leads to altered production of various molecules involved in accumulation and degradation of extracellular matrix.

[Seroepidemiological study on Helicobactor pylori infection in rural adult residents]

OBJECTIVE

To study the prevalence of Helicobactor pylori (Hp) infection in rural adult residents of China and its relation to serum levels of pepsinogen I (PG I), pepsinogen II (PG II) and gastrin (GAS).

METHODS

Serum levels of antibodies against Hp were determined with enzyme-liked immunosorbent assay (ELISA) in 1,504 residents aged over 30 in Zanhuang County of Hebei Province, and their serum levels of PG I, PG II and GAS, as well as PG I/PG II ratio, were analyzed quantitatively, with radioimmunoassay (RIA).

RESULTS

Positivity for serum Hp antibody accounted for 66.4% of the rural adults in Zanhuang County, without significant sex difference. There was no significant difference in positivity for serum Hp antibody between residents in the high and low prevalent areas of gastric cancer. Serum levels of PG I, PG II and GAS were significantly higher in those with positive serum IgG anti-Hp (62.3 micrograms/L, 15.45 micrograms/L and 74.00 pg/ml, respectively) than those negative (42.1 micrograms/L, 6.40 micrograms/L and 66.00 pg/ml, respectively), all with a P-value less than 0.005, and the ratio of serum PG I to PG II levels was significantly lower in the former (4.0) than that in the latter (6.6), with P < 0.005.

CONCLUSION

More than two thirds of the adult residents in Zanhuang County had infected with Hp, which could affect their serum levels of PG and GAS.

[A study on major chemical components of Uvaria grandiflora]

OBJECTIVE

To make clear the chemical constituents of Uvaria grandiflora (Annonaceae).

METHODS

Purification was performed using sephadex LH-20 permeation and silica gel chromatography. Structures of the purified components were determined on the basis of 1H, 13C NMR analysis and also by comparison with those of authentic compounds.

RESULTS

Two major triterpenes, suberosol and lupeol, were identified.

CONCLUSION

This paper is the first report on the identification of suberosol and lupeol from the gunus Uvaria.

Prostaglandin E1 activates the large-conductance KCa channel in human corporal smooth muscle cells

The large conductance calcium-sensitive potassium channel (KCa or maxi-K) is an important modulator of human corporal smooth muscle tone, and therefore, erectile capacity. The goal of this investigation was to evaluate the actions of prostaglandin E1 (PGE1), the most widely used and effective drug for the treatment of impotence, on the activity of the KCa channel, a prominent K+ current present in human corporal smooth muscle. Whole-cell patch clamp studies conducted on short-term cultured and enzymatically dissociated human corporal smooth muscle cells, revealed mean resting potentials of -50.8 +/- 2.1 mV (n = 8) and -34 +/- 4 mV (n = 8), respectively. In the attached-patch configuration, the corresponding single-channel slope conductance values for the KCa channel subtype were 173 +/- 4 pS (n = 8) in cultured cells, and 190 +/- 13 pS (n = 3) in freshly isolated myocytes. Furthermore, voltage clamp experiments revealed that relative to control values, the application of PGE1 to cultured cells (3.3 or 33 microM) elicited an apparent increase in both the open probability (Po; ranging from 1.2-23 fold), and the mean open time (5-6 fold) of the KCa channel at membrane potentials of +90 mV and +110 mV. PGE1-induced alterations in KCa channel activity were also observed in freshly isolated corporal myocytes. In the whole cell-recording mode, statistically significant, Charybdotoxin-sensitive (100 nM) 2-3 fold increases in the outward K+ currents were observed in both cultured and freshly isolated corporal myocytes. The presence of a PKA inhibitor (fragment 6-22 amide; 10 microM) in the pipette tip was also associated with a nearly complete ablation of the observed PGE1-induced whole cell K+ currents. Taken together, these data confirm and extend our previous observations, and indicate that PGE1-induced relaxation of human corporal smooth muscle is related, at least in part, to activation of the KCa channel subtype resulting in cellular hyperpolarization.

Delayed hypovolemic hypotension exacerbates the hemodynamic and histopathologic consequences of thromboembolic stroke in rats

Abnormalities in cerebrovascular reactivity or hemodynamic reserve are risk factors for stroke. The authors determined whether hemodynamic reserve is reduced in an experimental model of thromboembolic stroke. Nonocclusive common carotid artery thrombosis (CCAT) was produced in rats by a rose bengal-mediated photochemical insult, and moderate hypotension (60 mm Hg/30 min) was induced 1 hour later by hemorrhage. Alterations in local cerebral blood flow (ICBF) were assessed immediately after the hypotensive period by 14C-iodoantipyrine autoradiography, and histopathologic outcome was determined 3 days after CCAT. Compared to normotensive CCAT rats (n = 5), induced hypotension after CCAT (n = 7) led to enlarged regions of severe ischemia (i.e., mean ICBF < 0.24 mL/g/min) in the ipsilateral hemisphere. For example, induced hypotension increased the volume of severely ischemic sites from 16 +/- 4 mm3 (mean +/- SD) to 126 +/- 99 mm3 (P < 0.05). Histopathologic data also showed a larger volume of ischemic damage with secondary hypotension (n = 7) compared to normotension (22 +/- 15 mm3 versus 5 +/- 5 mm3, P < .05). Both hypotension-induced decreases in ICBF and ischemic pathology were commonly detected within cortical anterior and posterior borderzone areas and within the ipsilateral striatum and hippocampus. In contrast to CCAT, mechanical ligation of the common carotid artery plus hypotension (n = 8) did not produce significant histopathologic damage. Nonocclusive CCAT with secondary hypotension therefore predisposes the post-thrombotic brain to hemodynamic stress and structural damage.

Middle cerebral artery occlusion in the mouse by intraluminal suture coated with poly-L-lysine: neurological and histological validation

The present study was conducted to validate a modified method of temporary focal cerebral ischemia in the mouse; neurobehavioral function and histopathological infarction were quantitated following various periods of middle cerebral artery occlusion (MCAo). Male C57BL/6 mice were anesthetized with 3% halothane in a mixture of 30%O2/70%N2O delivered by face mask and were subjected to 30- to 180-min of temporary middle cerebral artery occlusion (MCAo) by an intraluminal suture coated with poly-l-lysine. Twenty-eight of 40 mice showed an initial high-grade neurological deficit (30-min MCAo, n=7; 60-min, n=8; 120-min, n=8; 180-min, n=5) when examined during MCAo; these were used for subsequent study. One day after MCAo, behavioral function was re-evaluated, and brains were perfusion-fixed and infarct volumes were measured. The initial neurological deficit improved at 24 h in mice with 30- or 60-min of prior MCAo but tended to persist in mice with 120- or 180-min insults. Following each duration of ischemia, mice exhibited ipsilateral infarcts. Small, inconsistent predominantly subcortical infarcts were present after 30-min MCAo, while longer occlusion periods gave rise to consistent foci of subcortical infarction involving striatum, septum, thalamus, and hippocampus, as well as areas of frontoparietal cortical infarction. The major advantages of the improved intraluminal MCAo model reported here, incorporating sutures coated with poly-l-lysine, include: a 100% incidence of infarction of predictable location and size in mice having an initial neurological deficit. Periods of 60- to 180-min MCA occlusion in this model yield sufficiently reproducible sequelae to permit the effects of various therapeutic agents on neurological outcome and size of infarction to be readily studied.

[Determination of plasma serotonins level in patients with pregnancy induced hypertension]

OBJECTIVE

To determine whether levels of serotonin(5-HT) and 5-hydroxy-indolescetic acid (5-HIAA) play an important role in the pathogenesis of pregnancy induced hypertension (PIH).

METHODS

Maternal venous blood were collected from 60 women with PIH and 40 normotensive pregnant women in third trimester as control, and umbilical venous blood were collected from 38 newborns in each groups. Plasma and platelet 5-HT and 5-HIAA levels were measured by spectrophotometry.

RESULTS

The mean 5-HT level was (54.16 +/- 10.13) nmol/L and 5-HIAA was (43.62 +/- 6.37) nmol/L in maternal plasma, while they were (50.23 +/- 7.83) nmol/L and (41.73 +/- 8.61) nmol/L in umbilical plasma respectively in the normotensive group. The mean 5-HT was (86.24 +/- 14.37) nmol/L and 5-HIAA was (62.37 +/- 8.34) nmol/L in maternal plasma of patients with PIH. While the mean 5-HT was (71.56 +/- 10.13) nmol/L and 5-HIAA was (62.37 +/- 11.37) nmol/L in umbilical plasma in PIH group. 5-HT and 5-HIAA levels in maternal and umbilical blood of PIH groups were significantly higher than that in the control group (P < 0.01).

CONCLUSIONS

The markedly elevated plasma 5-HT and 5-HIAA levels might be caused by the increased release of 5-HT by platelet. The result showed that elevated levels of 5-HT and 5-HIAA in patients with PIH might take part in the pathogenesis of PIH.

Mutations in a delta 8-delta 7 sterol isomerase in the tattered mouse and X-linked dominant chondrodysplasia punctata. jderry@immunex.com

Tattered (Td) is an X-linked, semi-dominant mouse mutation associated with prenatal male lethality. Heterozygous females are small and at 4-5 days of age develop patches of hyperkeratotic skin where no hair grows, resulting in a striping of the coat in adults. Craniofacial anomalies and twisted toes have also been observed in some affected females. A potential second allele of Td has also been described. The phenotype of Td is similar to that seen in heterozygous females with human X-linked dominant chondrodysplasia punctata (CDPX2, alternatively known as X-linked dominant Conradi-Hünermann-Happle syndrome) as well as another X-linked, semi-dominant mouse mutation, bare patches (Bpa). The Bpa gene has recently been identified and encodes a protein with homology to 3beta-hydroxysteroid dehydrogenases that functions in one of the later steps of cholesterol biosynthesis. CDPX2 patients display skin defects including linear or whorled atrophic and pigmentary lesions, striated hyperkeratosis, coarse lusterless hair and alopecia, cataracts and skeletal abnormalities including short stature, rhizomelic shortening of the limbs, epiphyseal stippling and craniofacial defects (MIM 302960). We have now identified the defect in Td mice as a single amino acid substitution in the delta8-delta7 sterol isomerase emopamil binding protein (Ebp; encoded by Ebp in mouse) and identified alterations in human EBP in seven unrelated CDPX2 patients.

Sequential changes in glial fibrillary acidic protein and gene expression following parasagittal fluid-percussion brain injury in rats

This study documents the regional and temporal patterns of glial fibrillary acidic protein (GFAP) RNA and protein expression after parasagittal fluid-percussion (F-P) brain injury (1.7 to 2.2 atm) in male Sprague-Dawley rats. In situ hybridization was conducted in 28 rats with a 35S-labeled antisense riboprobe to GFAP at 0.5, 2, and 6 hours and 1, 3, and 30 days after traumatic brain injury (TBI) or sham procedures. Immunocytochemical staining of GFAP was conducted in 20 rats at 1, 3, 7, and 30 days after TBI or sham procedures. At 0.5 and 2 hours after TBI, increased GFAP mRNA was restricted to superficial cortical areas underlying the impact site. At 24 hours, increased GFAP mRNA was observed throughout the traumatized hemisphere except within the histopathologically vulnerable lateral parietal cortex and external capsule. Contralateral expression within the hippocampus and cingulate and lateral cortices was also observed. Three days after TBI, GFAP mRNA expression was prominent overlying pial surfaces, in cortical regions surrounding the contusion, and within the hippocampus and lateral thalamus. Immunocytochemical visualization of GFAP at 1 and 3 days demonstrated reactive astrocytes overlying the pial surface, surrounding the cortical contusion, and within ipsilateral white matter tracts, hippocampus, and lateral thalamus. At 30 days, GFAP mRNA and protein expression were present within the deeper cortical layers of the lateral somatosensory cortex and lateral thalamus and throughout ipsilateral white matter tracts. These data demonstrate a complex pattern of GFAP mRNA and protein expression within gray and white matter tracts following F-P brain injury. Patterns of GFAP gene expression may be a sensitive molecular marker for evaluating the global response of the brain to focal injury in terms of progressive neurodegenerative as well as regenerative processes.

Converting Eu3+ between defect sites in BaFCl for persistent spectral hole burning

Persistent spectral hole burning (PSHB) is demonstrated in the (7)F(0)-->(5)D(0) optical transition of Eu(3+) doped into crystals of BaFCl. For Eu(3+) ions at two different lattice sites, persistent holes can be burned at temperatures below 77 K. The characteristics of the hole-burning process suggest that the observed PSHB effect is due to laser-excitation-induced site-to-site conversion. One type of Eu(3+) site is converted into another type of defect site. This process is not optically reversible, and holes can be erased only when the temperature increases to 150 K.

The putative mechanistic basis for the modulatory role of endothelin-1 in the altered vascular tone induced by Trypanosoma cruzi

Chagas' disease, caused by Trypanosoma cruzi, is an important cause of heart disease in Latin America. T. cruzi-induced microvascular compromise, in turn, is thought to play a major role in chagasic heart disease. Previous in vitro studies have implicated endothelin-1 (ET-1) as a potentially important vasomodulator present in increased levels in the supernatant of T. cruzi infected cultured human umbilical vein endothelial cells (HUVEC). Thus, the goal of the present investigation was to further evaluate the potentially important contribution of ET-1 to T. cruzi-induced alterations in vascular tone in vitro. Bioassay studies once again documented that exposure of isolated rat aortic rings to infected HUVEC supernatants elicited contractile responses whose steady-state magnitude was significantly greater than contractile responses elicited by exposure of aortic rings to uninfected HUVEC supernatants. Furthermore, the increased aortic contractility was significantly attenuated by the presence of the ET(A) subtype selective antagonists BMS-182,874 or BQ-123. Additionally, incubation of HUVEC with either verapamil or phosphoramidon prior to infection was also associated with reduced aortic contractility, upon exposure to the supernatant. Phosphoramidon, but not verapamil, produced a significant decrease in the measured ET-1 levels in the HUVEC supernatant. Consistent with the bioassay results, preincubation of Fura-2-loaded cultured rat aortic vascular smooth muscle cells with verapamil resulted in a near complete ablation of ET-1-induced transmembrane Ca2+ flux. Taken together, these data are consistent with the hypothesis that ET-1-induced vasoconstriction may play an important modulatory role in the vascular compromise characteristic of T. cruzi infection.

The gene mutated in bare patches and striated mice encodes a novel 3beta-hydroxysteroid dehydrogenase

X-linked dominant disorders that are exclusively lethal prenatally in hemizygous males have been described in human and mouse. None of the genes responsible has been isolated in either species. The bare patches (Bpa) and striated (Str) mouse mutations were originally identified in female offspring of X-irradiated males. Subsequently, additional independent alleles were described. We have previously mapped these X-linked dominant, male-lethal mutations to an overlapping region of 600 kb that is homologous to human Xq28 (ref. 4) and identified several candidate genes in this interval. Here we report mutations in one of these genes, Nsdhl, encoding an NAD(P)H steroid dehydrogenase-like protein, in two independent Bpa and three independent Str alleles. Quantitative analysis of sterols from tissues of affected Bpa mice support a role for Nsdhl in cholesterol biosynthesis. Our results demonstrate that Bpa and Str are allelic mutations and identify the first mammalian locus associated with an X-linked dominant, male-lethal phenotype. They also expand the spectrum of phenotypes associated with abnormalities of cholesterol metabolism.

Suppressive effect of carotenoids on the luminol dependent chemiluminescence of the stimulated rat macrophages

Rat macrophages stimulated by phorbol 12-myristate 13-acetate (PMA) produced significant chemiluminescence in luminol. Carotenoids suppressed the luminol-dependent chemiluminescence at the beginning and after two minutes of the stimulation. Canthaxanthin and bixin had higher suppressive activity that beta-carotene and lutein. The measurement of the absorption spectra of carotenoids showed that the absorption by carotenoids was diminished during the stimulation of macrophages. The results suggest that the suppressive effect of carotenoids may be due to their scavenging the reactive oxygen metabolites released by macrophages.

Ca2+-induced increases in steady-state concentrations of intracellular calcium are not required for inhibition of parathyroid hormone secretion

It has been well established that increases in extracellular calcium concentration ([Ca2+]) inhibit parathyroid hormone (PTH) secretion. The effects of [Ca2+] are mediated through a G-protein-coupled receptor that has been cloned and characterized. Additionally, it has been demonstrated in parathyroid cells that an increase in [Ca2+] results in an increase in steady-state levels of intracellular calcium ([Ca2+]i). At present, it has not been fully resolved whether changes in [Ca2+]i are related to changes in PTH secretion. In the current study, the effect of increased [Ca2+] on PTH secretion and the connection regarding changes in concentrations of intracellular calcium [Ca2+]i have been examined in primary cultures of bovine parathyroid cells. PTH secretion was measured by radioimmunoassay and intracellular calcium was determined by single cell calcium imaging. Bovine parathyroid cells pre-incubated with either 0.5 or 1 mM calcium responded to rapid increases in [Ca2+] (> or = 0.5 mM) with an immediate and sustained increase in steady-state levels of [Ca2+]i that persisted for time intervals greater than 15 minutes. Although the magnitude of the sustained increase in [Ca2+]i varied among individual cells (approximately 40% to > 300%), the overall pattern and course of time were similar in all cells examined (n = 142). In all trials, [Ca2+]i immediately returned to baseline levels following the addition of the calcium chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Additional control studies, however, suggest that sustained increases in [Ca2+]i do not correlate with regulation of parathyroid hormone secretion. Sustained elevations of [Ca2+]i were not observed when [Ca2+] was gradually increased by the addition of 0.1 mM increments at 1 minute intervals. Furthermore, the effect on inhibition of PTH secretion was the same regardless of whether [Ca2+] was increased by gradual or rapid addition.

Posttreatment with high-dose albumin reduces histopathological damage and improves neurological deficit following fluid percussion brain injury in rats

We have recently shown that high-dose human serum albumin (HSA) therapy confers marked histological protection in experimental middle cerebral artery occlusion. Thus, the purpose of this study was to determine whether treatment with high-dose HSA would protect in a rat model of traumatic brain injury (TBI). Twenty-four hours prior to TBI, the fluid percussion interface was positioned parasagittally over the right cerebral cortex. On the following day, fasted rats were anesthetized with 3% halothane, 70% nitrous oxide, and 30% oxygen and received right parieto-occipital parasagittal fluid-percussion injury (1.5-2.0 atm). Cranial and rectal temperatures were monitored throughout the experiment and held at normothermic levels (36.5-37.5 degrees C) by a warming lamp above the animal's head. The agent (25% human serum albumin, HSA) or vehicle (sodium chloride 0.9%) was administered i.v. (1% of body weight) 15 min after trauma. Behavioral function was evaluated in all rats before and after TBI (at 2 h, 24 h, 48 h, 72 h, and 7 days). Neurological function was graded on a scale of 0-12 (normal score = 0; maximal score = 12). Seven days after TBI, brains were perfusion-fixed, coronal sections at various levels were digitized, and contusion areas in the superficial, middle and deep layers of cortex and in the underlying fimbria were measured. HSA significantly improved the neurological score compared to saline at 24 h, 72 h, and 7 days after TBI (6.0 +/- 0.6 [albumin] versus 8.4 +/- 0.5 [saline]; 3.6 +/- 0.7 versus 6.8 +/- 1.0; and 2.6 +/- 0.6 versus 5.7 +/- 0.8, respectively; p < 0.05). HSA therapy also significantly reduced total contusion area (0.89 +/- 0.2 versus 1.82 +/- 0.3 mm2; p = 0.02). Our findings document that high-concentration albumin therapy instituted 15 min after trauma significantly improves the neurological score and reduces histological damage. We believe that this pharmacological agent may have promising potential for the clinical treatment of brain injury.

Trichostatin A up-regulates human papillomavirus type 11 upstream regulatory region-E6 promoter activity in undifferentiated primary human keratinocytes

Human papillomavirus (HPV) gene expression in squamous epithelia is differentiation dependent in benign patient lesions and in organotypic raft cultures of primary human keratinocytes (PHKs). Using the lacZ reporter in raft cultures, we previously showed that this transcriptional regulation of the HPV type 11 (HPV-11) enhancer-promoter located in the upstream regulatory region (URR) appears to have resulted from coordination between the transcription transactivators AP1, Oct1, and Sp1 in differentiated upper strata and the repressor C/EBP in proliferating basal cells. We report here that trichostatin A, a specific inhibitor of histone deacetylase, dramatically stimulated reporter gene activity from the wild-type HPV-11 URR or the C/EBP mutation in PHKs grown in undifferentiated submerged cultures. In epithelial raft cultures, up-regulation occurred predominantly in basal and parabasal strata; this effect was promoter specific, as expression of the lacZ reporter gene driven by the murine leukemia virus long terminal repeat (LTR), the keratin 14 promoter, or the involucrin promoter was not altered, nor was expression of endogenous keratin 10 and profilaggrin affected. However, the responses were not cell type or species specific, as identical results were observed for both HPV-11 URR-lacZ and LTR-lacZ in murine retrovirus producer cell lines of fibroblast origin.

Resistance of Staphylococcal enterotoxin B- induced proliferation and apoptosis to the effects of dexamethasone in mouse lymphocyte cultures

Staphylococcal enterotoxin B (SEB) is a superantigen causing lymphocyte proliferation and apoptosis. Glucocorticoids are immunosuppressants and are released immediately following SEB intoxication in mice. Whether glucocorticoids affect lymphocyte proliferation and apoptosis in SEB-intoxicated mice is still unknown. To study this question, we examined the effects of dexamethasone (DEX), a synthetic glucocorticoid, on SEB-stimulated lymphocyte cultures from mouse thymus and peripheral lymphoid tissues (PLT). SEB, as well as concanavalin A (Con A), induced lymphocyte proliferation which peaked on day 4 and declined significantly on day 7. As expected, in Con A-stimulated cultures, DEX completely suppressed the proliferation of lymphocytes from both the thymus and PLT. However, in SEB-stimulated cultures, while DEX completely suppressed thymocyte proliferation, it did not suppress PLT cell proliferation even at a high concentration of 10(-7) M. The proliferating cells were Vbeta8(+) T cells of both the CD4(+) and CD8(+) subsets. DEX caused apoptosis. SEB also caused apoptosis, which was manifested by a maximal DNA subdiploidy on day 4 and by a maximal DNA fragmentation on day 7. Both events appeared not to be affected by DEX. The failure of DEX to affect the proliferation and apoptosis was consistent with high levels of cytokines (IL-1alpha, IL-2, IL-4, IL-6 and IFN-gamma) produced in the SEB-stimulated cultures, suggesting that the cytokines act in concert to circumvent the effects of DEX.

Digital radiology using active matrix readout: amplified pixel detector array for fluoroscopy

Active matrix array technology has made possible the concept of flat panel imaging systems for radiography. In the conventional approach a thin-film circuit built on glass contains the necessary switching components (thin-film transistors or TFTs) to readout an image formed in either a phosphor or photoconductor layer. Extension of this concept to real time imaging--fluoroscopy--has had problems due to the very low noise required. A new design strategy for fluoroscopic active matrix flat panel detectors has therefore been investigated theoretically. In this approach, the active matrix has integrated thin-film amplifiers and readout electronics at each pixel and is called the amplified pixel detector array (APDA). Each amplified pixel consists of three thin-film transistors: an amplifier, a readout, and a reset TFT. The performance of the APDA approach compared to the conventional active matrix was investigated for two semiconductors commonly used to construct active matrix arrays--hydrogenated amorphous silicon and polycrystalline silicon. The results showed that with amplification close to the pixel, the noise from the external charge preamplifiers becomes insignificant. The thermal and flicker noise of the readout and the amplifying TFTs at the pixel become the dominant sources of noise. The magnitude of these noise sources is strongly dependent on the TFT geometry and its fabrication process. Both of these could be optimized to make the APDA active matrix operate at lower noise levels than is possible with the conventional approach. However, the APDA cannot be made to operate ideally (i.e., have noise limited only by the amount of radiation used) at the lowest exposure rate required in medical fluoroscopy.

A gene located at 56F1-2 in Drosophila melanogaster encodes a novel metazoan beta-like subunit of casein kinase II

Drosophila melanogaster casein kinase II (DmCKII) is composed of catalytic alpha and regulatory beta subunits associated as an alpha2beta2 heterotetramer. Using the two-hybrid system, we have screened a Drosophila embryo cDNA library for proteins that interact with DmCKII alpha. One of the cDNAs encodes a novel beta-like polypeptide, which we designate beta'. In situ hybridization localizes the corresponding gene to 56F1-2, a site distinct from that of both the beta gene and the Stellate family of beta-like sequences. The predicted sequence of beta' is more closely related to the beta subunit of Drosophila and other metazoans than to the Stellate family of proteins, suggesting that it is a second regulatory subunit. In vitro reconstitution studies show that a GST-beta' fusion protein associates with the alpha subunit to generate a tetrameric complex with regulatory properties similar to those of the native alpha2beta2 holoenzyme. The data are consistent with the proposed role of the beta' subunit as an integral component of the holoenzyme.

Quantitation of multiple gene expression by in situ hybridization autoradiography: accurate normalization using Bayes classifier

In the method of in situ hybridization autoradiography, quantitative comparisons among multiple mRNA signals have proven difficult for many reasons, attributable both to technical factors (e.g. different probe specific activities) as well as to large differences in the patterns and levels of expression of different genes in pathologic states. Here we report a standardized normalization procedure for in situ hybridization autoradiography, employing a Bayes classifier, which permits the comparison of multiple mRNA probes. Autoradiograms of different probes in individual animals are first digitized and converted to units of radioactivity. Next, pixel-distribution histograms are generated for each mRNA signal. The Bayes classifier is then used to establish an optimal threshold to distinguish activated and non-activated pixels. This threshold also defines the minimal level of mRNA expression. The maximal mRNA signal is defined as the mean + 3 SD of the activated pixel distribution. We then use a linear transformation to convert each pixel from absolute activity to percentage of maximal mRNA signal for that particular probe. The normalized autoradiographic images can then be averaged to represent group trends and can be compared by standard statistical methods. We illustrate this normalization procedure using in situ hybridization autoradiography for three genes (GADD45, HSP70 and MAP2) expressed in the brains of rats studied at various recirculation times following transient (2 h) middle cerebral artery occlusion. The Bayes classifier is reviewed and its analytical application is presented. Step-by-step examples of intermediate steps are presented, construction of averaged data sets, and pixel-based statistical comparisons among expressed genes.

Changes in phosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) in processing of short-term and long-term memories after passive avoidance learning

Characteristic autophosphorylation of calcium/ calmodulin-dependent protein kinase II (CaMKII) and its consequences have made this kinase an interesting target in studying the molecular pathway for important neuronal functions including learning and memory formation. In this article, we use immunoprecipitation and immunoblotting methods to detect changes in phosphorylation of CaMKII during memory formation in 1-day-old chicks trained in a single trial passive avoidance task. A 60-kDa protein has been immunoprecipitated from the chick brain with an anti-rabbit CaMKII antibody. This protein shows strong and specific immunoactivities with antibodies against the calmodulin binding site of CaMKII, and the N and C terminals of beta-CaMKII. Commercially available anti-phosphoserine and anti-phosphothreonine antibodies are shown to sensitively detect phosphorylation of purified CaMKII. The basal phosphorylation of CaMKII from the intermediate medial hyperstriatum ventrale (IMHV) and lobus parolfactorius (LPO) regions of the chick brain is shown to be largely right hemisphere-lateralized. When chicks are subjected to a passive avoidance training experience, a specific increase in CaMKII phosphorylation is induced in the IMHV and LPO of the left hemisphere from those chicks whose memory for the training experience is successfully retrieved. While this specific increase in CaMKII phosphorylation is seen in both the left IMHV and left LPO in short-term memory, it is detectable only in the left LPO associated with long-term memory retrieval. The present results provide evidence that in vivo changes in phosphorylation of CaMKII are associated specifically with processing of distinct memory stages, which take place in specific brain regions.

Influence of early posttraumatic hypothermia therapy on local cerebral blood flow and glucose metabolism after fluid-percussion brain injury

OBJECT

Using autoradiographic image averaging, the authors recently described prominent foci of marked glucose metabolism-greater-than-blood-flow uncoupling in the acutely traumatized rat brain. Because hypothermia is known to ameliorate injury in this and other injury models, the authors designed the present study to assess the effects of posttraumatic therapeutic hypothermia on the local cerebral metabolic rate of glucose (LCMRglu) and local cerebral blood flow (LCBF) following moderate parasagittal fluid-percussion head injury (FPI) in rats.

METHODS

Either cranial hypothermia (30 degrees C) or normothermia (37 degrees C) was induced for 3 hours in matched groups of rats immediately after FPI; LCMRglu and LCBF were assessed 3 hours after concluding these temperature manipulations. In rats subjected to FPI, regardless of whether normothermia or hypothermia ensued, LCBF was reduced relative to the sham-injury groups. In addition, when FPI was followed by hypothermia (FPI-30 degrees C group), the subsequent LCBF was significantly lower (35-38% on average) than in FPI-37 degrees C rats. Statistical mapping of LCBF difference imaging data revealed confluent cortical and subcortical zones of significantly reduced LCBF (largely ipsilateral to the prior injury) in FPI-30 degrees C rats relative to the FPI-37 degrees C group. Local glucose utilization was reduced in both hemispheres of FPI-37 degrees C rats relative to the sham-injury group and was lower in the right (traumatized) hemisphere than in the left. However, LCMRglu values were largely unaffected by temperature manipulation in either the FPI or sham-injury groups. The LCMRglu/LCBF ratio was nearly doubled in FPI-30 degrees C rats relative to the FPI-37 degrees C group, in a diffuse and bihemispheric fashion. Linear regression analysis comparing LCMRglu and LCBF revealed that the FPI-37 degrees C and FPI-30 degrees C data sets were completely nonoverlapping, whereas the two sham-injury data sets were intermixed.

CONCLUSIONS

Despite its proven neuroprotective efficacy, early posttraumatic hypothermia (30 degrees C for 3 hours) nonetheless induces a moderate decline in cerebral perfusion without the (anticipated) improvement in cerebral glucose utilization, so that a state of mild metabolism-greater-than-blood-flow dissociation is perpetuated.

Characterization of the fibronectin binding motif for a unique mycobacterial fibronectin attachment protein, FAP

Studies were performed to define the fibronectin binding motif of the previously identified Mycobacterium avium fibronectin attachment protein (FAP-A). Using synthetic peptides of a previously identified fibronectin binding region (amino acids 269-292), the minimal binding sequence was determined to be 12 amino acids, 269-280 (FAP-A-(269-280)). Synthetic peptides were prepared in which each amino acid in the 269-280 sequence was substituted with Ala. Assessment of the effect of Ala substitution on fibronectin binding showed that the presence of Ala at amino acids 273-276 (RWFV) completely abrogated fibronectin binding activity. Furthermore, the ability to inhibit the attachment of viable Mycobacterium bovis BCG to fibronectin was abrogated by Ala substitution at the RWFV sites. To validate the function of RWFV, further studies were performed with recombinant FAP-A in which single Ala mutations were generated for the RWFV sites and as controls at amino acids 269 and 280. Mutant FAP-A containing single Ala substitutions at the RWFV sites (amino acids 273, 274, 275, or 276) showed significant abrogation of fibronectin binding function. Recombinant FAP-A with Ala substitutions at either 269 or 280 showed wild type activity. When the four essential amino acids (RWFV) were either substituted en bloc with Ala or were all deleted, complete loss of fibronectin binding function was observed. Control recombinant proteins with en bloc Ala substitutions or deletions at four positions outside the fibronectin binding region (amino acids 255-257) retained functional activity. These data show that the RWFV sequence is necessary for fibronectin binding function of FAP-A. Furthermore, the data suggest that mycobacterial FAP proteins, all of which share the RWFV binding motif, constitute a family of highly homologous proteins that bind fibronectin in a unique manner.

Bone resorption induced by parathyroid hormone is strikingly diminished in collagenase-resistant mutant mice

Parathyroid hormone (PTH) stimulates bone resorption by acting directly on osteoblasts/stromal cells and then indirectly to increase differentiation and function of osteoclasts. PTH acting on osteoblasts/stromal cells increases collagenase gene transcription and synthesis. To assess the role of collagenase in the bone resorptive actions of PTH, we used mice homozygous (r/r) for a targeted mutation (r) in Col1a1 that are resistant to collagenase cleavage of type I collagen. Human PTH(1-34) was injected subcutaneously over the hemicalvariae in wild-type (+/+) or r/r mice four times daily for three days. Osteoclast numbers, the size of the bone marrow spaces and periosteal proliferation were increased in calvariae from PTH-treated +/+ mice, whereas in r/r mice, PTH-induced bone resorption responses were minimal. The r/r mice were not resistant to other skeletal effects of PTH because abundant interstitial collagenase mRNA was detected in the calvarial periosteum of PTH-treated, but not vehicle-treated, r/r and +/+ mice. Calcemic responses, 0.5-10 hours after intraperitoneal injection of PTH, were blunted in r/r mice versus +/+ mice. Thus, collagenase cleavage of type I collagen is necessary for PTH induction of osteoclastic bone resorption.

Medical complications in long-term survivors with X-linked myotubular myopathy

OBJECTIVES

X-linked myotubular myopathy (MTM1) is a rare developmental disorder of skeletal muscle characterized by the presence of central nuclei in biopsy specimens from affected male subjects. Until recently, the disorder was usually fatal within the first year of life. This study was undertaken to determine the outcome in long-term survivors (>1 year of age) with MTM1.

METHODS

Clinical data were obtained on 55 male subjects from 49 independent North American families for which a mutation was identified in the X-linked myotubularin gene by direct genomic sequencing. Medical records were reviewed and families were interviewed to ascertain features at birth, length of survival, developmental milestones, and medical complications.

RESULTS

Seventy-four percent (26 of 35) of the affected male subjects over the age of 1 year are living (range, 1 to 27 years); 80% remain completely or partially ventilator-dependent. In the absence of significant hypoxia, cognitive development is normal, and the muscle disorder appears nonprogressive. Several patients have had other medical problems not previously reported to be associated with MTM1. These include pyloric stenosis (4 male subjects from 3 families), spherocytosis (2 patients), gallstones (4 patients), kidney stones or nephrocalcinosis (2 patients), a vitamin K responsive bleeding diathesis (2 patients), and height >/=90% for age (40% of the patients). Six patients have had biochemical evidence of liver dysfunction, and 2 patients died after significant liver hemorrhage.

CONCLUSIONS

These data suggest that the prognosis for X-linked MTM may not be as poor as previously reported. However, at least some long-term survivors appear at risk for medical complications involving other organ systems, and patients should be carefully monitored for these potentially life-threatening complications. The pleiotropic symptoms demonstrated in these patients strongly suggest that the function of the MTM1 protein is not limited to developing muscle cells.

A distal element in the HPV-11 upstream regulatory region contributes to promoter repression in basal keratinocytes in squamous epithelium

In benign squamous lesions and in organotypic epithelial cultures, the human papillomavirus (HPV) E6 and E7 genes are transcriptionally up-regulated in differentiated, spinous keratinocytes. We previously identified sequence elements in the enhancer-promoter regions of HPV types 18 and 11 important for this promoter regulation by using the bacterial LacZ reporter gene in stratified raft cultures of primary human keratinocytes (PHKs) or in submerged, proliferating cultures acutely transduced with recombinant retroviruses. Notably, mutations in the promoter-proximal Sp1, Oct1, and AP1 sites each significantly reduce reporter activity in differentiated cells, indicating that the bound factors are transcription transactivators. In the present study, we performed further mutagenesis on distal motifs in the HPV-11 regulatory region in PHKs in submerged and raft cultures. Mutations in an AP2-like site, three individual NF-1 sites, or five NF-1 sites collectively reduced promoter activity slightly in differentiated cells. A mutation in a putative glucocorticoid response element had no discernable effect in the presence or the absence of dexamethasone. However, mutations in a C/EBP binding site, especially the distal site, strikingly up-regulated reporter gene expression, particularly in basal and lower spinous cells, implicating bound protein as a transcription repressor. Collectively, these results demonstrate that the overall differentiation-dependent papillomaviral gene expression observed in vivo and in vitro involves promoter repression in the lower strata and activation in the upper, differentiated strata.

Propanil affects transcriptional and posttranscriptional regulation of IL-2 expression in activated EL-4 cells

The amide-class herbicide, propanil, causes numerous immunomodulary effects in animal models. In the present study, we investigated the effect of propanil on IL-2 expression and production in the murine lymphoma T cell line, EL-4. When supernatants of cells stimulated with phorbol 12-myristate 13-acetate in the presence of propanil were assessed by enzyme-linked immunosorbent assay, IL-2 levels were dose-dependently decreased by 20 and 50 microM of propanil but not at 10 microM. Quantitative Northern blot analysis of peak IL-2 message levels also showed a dose-dependent decrease. The kinetic pattern of message production, however, was unaffected. To determine if the reduced message production was due to reduced signaling or message stability, nuclear run-on and mRNA stability assays were performed. Nuclear run-on assays determined that the transcription rate of the IL-2 gene was decreased approximately 50% in the presence of 20 microM propanil, indicating that it was able to interfere with signal transduction. IL-2 message stability assays also demonstrated a reduction in message stability. Thus, propanil appears to reduce IL-2 production by affecting the signal transduction pathway and IL-2 message stability.

[Extensive transbasal approach for removal of tumours in the nasal, sphenoid and clival regions]

OBJECTIVE

To improve operative results of removal of the tumors in midline cranial base and the reconstruction of defect at frontal base through modification of the operative approach and techniques.

METHODS

Extensive transbasal approach was used in 15 patients with tumours in the nasal, sphenoid and clival regions.

RESULTS

The tumor was removed in 10 patients, near totally removed in 4 and partial removed in 1. The operative results of all patients were excellent except an elderly patient with mild operative morbidity.

CONCLUSIONS

The procedure we used expand the operative indications for the tumors situated at the midline cranial base and improve the operative results. The procedure has advantages such as wide operative space, reliable reconstruction of the frontal base, and no severe complications.

Pixel-based image analysis of HSP70, GADD45 and MAP2 mRNA expression after focal cerebral ischemia: hemodynamic and histological correlates

Gene expression studies with in situ hybridization after focal brain ischemia indicate a variety of distinct anatomical patterns. An important question is to what extent such reactive gene expression correlates with neuronal damage or survival. To study these questions, we focused on two stressed-induced genes, heat shock protein 70 (HSP70) and growth-arrest and DNA damage-inducible gene (GADD) 45 mRNA, and we compared reactive changes in mRNA to loss of the constitutive signal for microtubule-associated protein 2 (MAP2) mRNA. A pixel-based image analysis of mRNA signals was carried out using a highly reproducible model of focal brain ischemia. A poly-l-lysine coated filament was used to occlude the origin of the middle cerebral artery (MCA) for 2 h in ventilated, normothermic rats. Brains were collected after 0, 1, 3 and 6 h, and 1, 3 and 7 days. In situ hybridization analysis was carried out for HSP70 mRNA, GADD45 mRNA and MAP2 mRNA. Autoradiographic data sets were averaged and co-mapped into a common template of the rat brain. These data sets were then compared on a pixel-by-pixel basis with previously acquired image data sets derived from quantitative studies of local cerebral blood flow (LCBF) (obtained at the end of 2-h ischemia) of and infarctive histopathology (obtained at 3 days) in the same focal ischemia model. HSP70 mRNA and GADD45 mRNA were grossly elevated in the hemisphere subjected to ischemia during the first day. Pixel-based analysis showed a strong correlation between HSP70 mRNA signals, the degree of early blood-flow reduction and the probability of histological infarction. GADD45 mRNA was expressed in a more variable fashion. Decreases in MAP2 mRNA signals at 1, 3 and 7 days correlated strongly with histological infarction. These co-mapping procedures allow us to conclude that HSP70 mRNA is a robust indicator of ischemic stress and histological outcome after 2 h of focal brain ischemia. The topographic features of GADD45 expression suggest its possible role in conferring resistance to ischemic injury. Finally, our results indicate that local decreases in constitutive MAP2 expression at 1 day and beyond may be used as a robust marker of tissue regions having a high probability of focal infarction.

Time domains of neuronal Ca2+ signaling and associative memory: steps through a calexcitin, ryanodine receptor, K+ channel cascade

Synaptic changes that underlie associative learning and memory begin with temporally related activity of two or more independent synaptic inputs to common postsynaptic targets. In turn, temporally related molecular events regulate cytosolic Ca2+ during progressively longer-lasting time domains. Associative learning behaviors of living animals have been correlated with changes of neuronal voltage-dependent K+ currents, protein kinase C-mediated phosphorylation and synthesis of the Ca2+ and GTP-binding protein, calexcitin (CE),and increased expression of the Ca2+-releasing ryanodine receptor (type II). These molecular events, some of which have been found to be dysfunctional in Alzheimer's disease, provide means of altering dendritic excitability and thus synaptic efficacy during induction, consolidation and storage of associative memory. Apparently, such stages of behavioral learning correspond to sequential differences of Ca2+ signaling that could occur in spatially segregated dendritic compartments distributed across brain structures, such as the hippocampus.

Diffusion-weighted magnetic resonance imaging confirms marked neuroprotective efficacy of albumin therapy in focal cerebral ischemia

BACKGROUND AND PURPOSE

We have recently shown high-dose human serum albumin therapy to confer marked histological protection in experimental middle cerebral artery occlusion (MCAo). We have now used diffusion-weighted magnetic resonance imaging (DWI) in conjunction with morphological methods to expand our understanding of this therapeutic approach.

METHODS

Physiologically controlled Sprague-Dawley rats received 2-hour MCAo by the modified intraluminal suture method. Treated rats received 25% human serum albumin solution (1% by body weight) immediately after the MCA was reopened. Vehicle-treated rats received saline. Computer-based image averaging was used to analyze DWI data obtained 24 hours after MCAo and light-microscopic histopathology obtained at 3 days. In a matched series, plasma osmolality and colloid oncotic pressure, as well as brain water content, were determined.

RESULTS

Albumin therapy, which lowered the hematocrit on average by 37% and raised plasma colloid oncotic pressure by 56%, improved the neurological score throughout the 3-day survival period. Within the ischemic focus, the apparent diffusion coefficient (ADC) computed from DWI data declined by 40% in vehicle-treated rats but was preserved at near-normal levels (8% decline) in albumin-treated rats (P<0.001). Albumin also led to higher ADC values within unlesioned brain regions. Histology revealed large consistent cortical and subcortical infarcts in vehicle-treated rats, while albumin therapy reduced infarct volume at these sites, on average, by 84% and 33%, respectively. Total infarct volume was reduced by 66% and brain swelling was virtually eliminated by albumin treatment. Microscopically, while infarcted regions of vehicle-treated rats had the typical changes of pannecrosis, infarcted zones of albumin-treated brains showed persistence of vascular endothelium and prominent microglial activation, suggesting that albumin therapy may help to preserve the neuropil within zones of residual infarction.

CONCLUSIONS

These findings confirm the striking neuroprotective efficacy of albumin therapy in focal cerebral ischemia and reveal that this effect is associated with DWI normalization and a mitigation of pannecrotic changes within zones of residual injury.

Production of serotonin syndrome by 8-OH DPAT in Cryptotis parva

We have previously shown that the 5-HT2A/C agonist, DOI, potently and in a dose-dependent manner produces the head-twitch response in the least shrew (Cryptotis parva) via the activation of serotonergic 5-HT2A receptors. The purpose of the present study was to determine whether activation of 5-HT1A receptors by its selective agonist, 8-OH DPAT, can induce the serotonin syndrome (SS) in this species. In the rat, the symptoms of SS include: forepaw splaying, hindleg abduction, forepaw treading, flat body posture, tremor, and straub tail. Intraperitoneal (i.p.) administration of 8-OH DPAT produced four classic symptoms (forepaw splaying, hindleg abduction, forepaw treading, and straub tail) of SS in the least shrew in a dose-dependent manner in the 30-min observation period. The mean total cumulative score for all components of SS also significantly increased in intensity in a dose-dependent fashion. Administration of selective 5-HT1A antagonists [S(-)UH 301 or NAN-190] potently blocked the 8-OH DPAT-induced mean total SS score in a dose-dependent manner. Moreover, these antagonists had similar potencies as indicated by their identical ID50 values (0.5 and 0.52 mg/kg respectively). However, unexpectedly and unlike the published findings in the rat, the nonselective 5-HT1A antagonist with b-blocking activity, propranolol, failed to attenuate the induced response in this species. As was expected, the selective 5-HT2A/C antagonist, SR 46349B, did not affect the intensity 8-OH DPAT-induced symptoms. Overall, these data suggest that the SS produced by 8-OH DPAT in the least shrew is mediated via the activation of serotonergic 5-HT1A receptors. In addition, propranolol is not a useful 5-HT1A antagonist in this species.

Digital x-ray imaging using amorphous selenium: reduction of aliasing

Alias reduction is analyzed with the concept of an equivalent presampling filter, and a mathematical approach is established to find the equivalent presampling filter corresponding to specific digital image processing algorithms. The effects of different sampling period T and sampling aperture tau on aliasing artifacts and on the resultant detective quantum efficiency (DQE) for a self-scanned, flat-panel, amorphous selenium detector are obtained. Different effective apertures can be obtained from the same detector by averaging signals over adjacent pixels. It is shown that adding outputs from M adjacent pixels is equivalent to introducing an equivalent presampling filter with special properties. Appropriate selection of the averaging parameters (M and weights) is shown to reduce the aliasing artifact in the resultant image. The effect of incomplete charge collection due to geometrical effects (fill factor) is examined. It is shown that a large fill factor is desirable for aliasing reduction. The relationship between a digital filter applied to the sampled signal and its equivalent presampling analog filter is also established. Analytical formulas for the sampled spectrum of white signal and for the sampled power spectrum of white noise are obtained for aperture functions with a spatially uniform response. These formulas take into accounts aliasing artifacts, signal correlation and aperture function response, and demonstrate the dependence of sampled spectra on T and tau. With these formulas the detective quantum efficiency DQE is derived. It is shown that the resultant DQE depends only on the fill factor and the size of readout electrode tau 0, but is completely independent of the degree or type of pixel averaging. That is, even though the pixel averaging method reduces aliasing it leaves DQE (omega) unchanged. When significant amplifier noise is present the DQE obtained with the pixel averaging method can be better than those obtained with an analog presampling filter. Finally, it is pointed out that the requirement of reducing aliasing artifacts conflicts with other requirements for a detector such as maximizing modulation transfer function (MTF). A careful and practical compromise has to be made by a detector designer in choosing the extent to which the aliasing artifacts are eliminated.

(+)-Verussurine, a new steroidal alkaloid from the roots and rhizomes of veratrum nigrum var. ussuriense and structure revision of (+)-verabenzoamine1

Two minor steroidal alkaloids, 1 and 2, have been isolated from the roots and rhizomes of Veratrum nigrum var. ussuriense. Their structures have been determined by the use of spectral data as 7-O-acetyl-15-O-(2-methylbutyroyl)-3-O-veratroylgermine (1) and 15-O-(2-methylbutyroyl)-3-O-veratroylgermine (2). By spectral data comparison with verabenzoamine, the structure of the latter compound has been revised from the previously reported 7-O-acetyl-15-O-(2-methylbutyroyl)-3-O-veratroylgermine (1) to 15-O-(2-methylbutyroyl)-3-O-veratroylgermine (2). Accordingly, alkaloid 1 [7-O-acetyl-15-O-(2-methylbutyroyl)-3-O-veratroylgermine] must be new, and it was given the trivial name verussurine.

[Detection of Hep-2 and hepatoma cell line chromosomal aberration by using fluorescence in situ hybridization]

OBJECTIVE

To study the chromosomal aberration of hepatoma cell line (1172) and laryngocarcinoma cell line (Hep-2).

METHODS

Fluorescence in situ hybridization (FISH) was used with nine chromosomal special libraries.

RESULTS

The abnormal signals indicated that very complicated aberrations existed in the two cell lines. This suggested that the aberrations also existed in other chromosomes not yet studied. In 1172, the major type was structure aberration, but in Hep-2, numerical abnormality was shown in almost all chromosomes studied.

CONCLUSION

Compared with traditional cytological methods, this technique has the advantages of being quicker and more accurate and sensitive.

[Chemical research on stilbenes from Veratrum macckii Reg]

OBJECTIVE

To study the components in rhizome of Veratrum macckii.

METHODS

Column chromatography and preparative thin layer chromatography with silica gel were employed for the isolation and purification of constituents. The structures were elucidated by IR, MS and 1H-NMR analysis.

RESULTS

Two compounds were obtained and elucidated as resveratrol and 2,3',4,5'-tetrahydroxystilbene.

CONCLUSION

The two compounds were separated from V. macckii for the first time.

Ritanserin, a 5-HT2 receptor antagonist, increases subcortical blood flow following photothrombotic middle cerebral artery occlusion in rats

It has been proposed that the reversal of serotonin-mediated vasoconstriction accounts for the neuroprotective effect of serotonin (5-HT2) receptor blockade in focal cerebral ischemia. We investigated the effect of pretreatment with ritanserin, a 5-HT2 receptor antagonist, on cerebral blood flow in a model of photothrombotic middle cerebral artery occlusion in rats. Local cerebral blood flow was measured by iodoantipyrine autoradiography 30 minutes after induction of ischemia. Using a novel image-alignment algorithm, 3-dimensional reconstructions of averaged cerebral blood flow were calculated. The difference-image of local cerebral blood flow between ritanserin and vehicle-treated animals revealed a subcortical zone underlying the ischemic cortex where cerebral blood flow was markedly enhanced indicating a beneficial hemodynamic effect of ritanserin. Three-dimensional image analysis provides a powerful tool to detect inter-group differences of cerebral blood flow which are underestimated by conventional types of data analysis.

[Isolation and identification of triterpenoide compound from Patrinia scabiosaefolia]

In this paper, a triterpenoide was isolated from the roots and rhizomes of Patrinia scabiosaefolia Fish ex Link. Its structure was identified by combination of chemical reactions and spectrum analysis as 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl-hederagenin ester. The compound was found in the Patrinia for the first time.

Fructose induced deactivation of glucose-6-phosphate dehydrogenase activity and its prevention by pyruvate: implications in cataract prevention

Glucose-6-phosphate dehydrogenase (G6PDH) is an important lens enzyme diverting about 14% of the tissue glucose to the hexose monophosphate shunt pathway. The main function of such a pronounced activity of the enzyme is to support reductive biosyntheses, as well as to maintain a reducing environment in the tissue so as to prevent oxy-radical induced damage and consequent cataract formation. Sugars are one of the well-known cataractogenic agents. Several reports suggest that the cataractogenic effect of the sugars in diabetes as well as in normal aging is initiated by the glycation of the proteins including the enzymes and subsequent formation of more complex and biologically inactive or harmful structures. In a diabetic lens the concentration of fructose exceeds significantly the concentration of glucose, suggesting that the contribution of fructosylation may be greater than that of glucosylation. These studies were undertaken to examine further the possibility that in addition to glycation, generation of oxygen free radicals by fructose and consequent oxidative modifications in certain enzymes may be an important participant in the cataractogenic process. This hypothesis was tested by using G6PDH. The enzyme was incubated with various levels of fructose (0-20mM) and its activity determined as a function of time. This led to a significant loss of its activity, which was prevented by superoxide dismutase, catalase, mannitol and myoinositol. Most interestingly, pyruvate at levels between 0.2 and 1.0 mM also offered substantial protection. Hence, the results, while elucidating further the mechanism of enzyme deactivation by sugars such as fructose, also demonstrate the possibility of therapeutic prevention of cataracts by pyruvate and other such keto acids, in diabetes and other disabilities involving oxygen free radicals in the pathogenetic process.