Macroscopic and roentgenographic anatomy of the skull of the ferret (Mustela putorius furo)

Normal macroscopic and roentgenographic features of the skull of the ferret (Mustela putorius furo) were examined and described. Data were based on a sample of 100 (50 male and 50 female) adult ferrets of known body weight and age. The skull was described macroscopically according to six standard views, i.e. dorsal, lateral, ventral, caudal, cranial and midsagittal. The mandible was described separately. The roentgenographic characteristics of the ferret skull were demonstrated only in lateral and dorsoventral projections. Furthermore, the skull length and width as well as the minimum frontal width were measured, and skull indices were derived from relevant measurements. Sexual dimorphism was examined both morphologically and craniometrically. Besides the common features of a carnivore skull, the ferret skull is relatively elongated and flat with a short facial region. The skulls of adult male ferrets are about 17% longer and 22% wider than those of the females. Significant sexual dimorphism also exists regarding certain skull indices. The general features and some dimensional parameters of the adult ferret skull support the contention that the ferret would be an interesting and workable alternative animal model in craniofacial research.

(13)C NMR investigation of the superconductor MgCNi(3) up to 800 K

We report (13)C NMR characterization of the new superconductor MgCNi(3) [T. He et al., Nature (London) 411, 54 (2001)]. We found that both the uniform spin susceptibility and the spin fluctuations show a strong enhancement with decreasing temperature, and saturate below approximately 50 K and approximately 20 K, respectively. The nuclear spin-lattice relaxation rate 1/(13)T(1) exhibits typical behavior for isotropic s-wave superconductivity with a coherence peak below T(c) = 7.0 K that grows with decreasing magnetic field.

Similarity of an Aroclor-based and a full congener-based method in determining total PCBs and a modeling approach to estimate Aroclor speciation from congener-specific PCB data

Polychlorinated biphenyls (PCBs) have entered the environment in North America as Aroclor technical mixtures. Most methods used for the determination of total PCB levels in environmental samples visually match patterns of sample peaks to those in Aroclor standards. Concern over the accuracy of Aroclor-based measurements on compositionally modified samples coupled with advancements in analytical techniques have led to congener-specific PCB analysis. In this study, the PCB data from 27 tissue samples determined by an Aroclor-based method and a full congener method were compared in terms of total PCB concentration to assess the reliability of this Aroclor technique for total PCB determination. Our data show a strong correlation between the sum of Aroclors and the total PCBs obtained from the full congener determinations. We also developed a model using the compositional data from three Aroclors (1242, 1254, and 1260) to determine the amount of compositional alteration from original Aroclor patterns in environmental samples. Full congener data, from a variety of tissue types and trophic levels, examined using this method showed that compositional modification from original Aroclor patterns increases with trophic level, with the greatest modification observed in seal and killer whale samples. This result agrees both with expectation and with what has been found in other studies. Such techniques, which connect congener-specific PCB data to Aroclor contamination, may prove useful to investigations into environmental and metabolic fate and transfer processes.

Disturbances in hepatic cell-cycle regulation in mice with assembly-deficient keratins 8/18

Simple epithelial tissues such as liver and pancreas express keratins 8 (K8) and 18 (K18) as their major intermediate filament proteins. K8 and K18 null mice and transgenic mice that express mutant K18 (K18C) manifest several hepatocyte abnormalities and demonstrate that K8/18 are important in maintaining liver tissue and cell integrity, although other potential functions remain uncharacterized. Here, we report an additional abnormal liver phenotype, which is similar in K8 null, K18 null, and K18C mouse models. Liver histologic examination showed large polynuclear areas that lacked cell membranes, desmosomal structures, and filamentous actin. Similar, but less prominent, areas were observed in the pancreas. The parenchyma outside the polynuclear areas displayed irregular sinusoidal structures and markedly enlarged nuclei. Most K8 null hepatocytes were positive for the proliferating cell nuclear antigen (PCNA) with a doubled DNA content in comparison with the predominantly PCNA-negative wild-type hepatocytes. The distribution of the 14-3-3zeta protein was also altered in K8 null mice. Taken together, our results indicate that absence of keratin filaments causes disturbances in cell-cycle regulation, driving cells into the S-G2 phase and causing aberrant cytokinesis. These effects could stem from disturbed functions of K8/18-dependent cell-cycle regulators, such as the signaling integrator, 14-3-3.

[A comparison between the effects of albuterol and isoproterenol in bronchodilation test]

OBJECTIVE

To compare albuterol with isoproterenol as a bronchodilator in pulmonary function test and their value in the diagnosis and differential diagnosis of asthma.

METHODS

Two groups (59 patients with asthma and 37 patients with COPD) were included in this study, and the patients of each group were randomly divided into 2 subgroups. The patients in the 2 subgroups inspired the two drugs in a cross-over by odd or even days. The pulmonary functions were evaluated.

RESULTS

The changing rates of pulmonary functions induced by the two drugs in the two groups were positively correlated (P < 0.005), The changing rates of FEV1, MMEF, Raw, sGaw induced by albuterol were higher than the ones induced by isoproterenol in patients with asthma(P < 0.02), however the changing rates of FVC and PEF in asthma cases and all the above parameters in COPD cases were not significantly different between the two drugs(P > 0.10). The comparison of positive case number between asthma and COPD cases induced by both drugs showed significant difference(P < 0.005); especially, when the positive rate of sGaw induced by albuterol in asthma cases reached 98%, the positive rates in COPD cases was generally much lower.

CONCLUSION

Bronchodilation test is a valuable diagnostic method for asthma. In this study, albuterol was superior to isoproterenol. The most sensitive index in bronchodilation test was sGaw, then in order, FEV1(92%), MMEF and Raw; the FVC and PEF were relatively insensitive.

[The effect of leukotriene antagonist on the parameters of dose-response curve obtained after methacholine challenge test]

OBJECTIVE

To investigate the effect of leukotriene antagonist (zafirlucast) on the parameters of dose-response curve (DRC) obtained after methacholine challenge test.

METHODS

A therapy trial was conducted with the use of zafirlucast in 20 cases of cough variant asthma (CVA) and 20 cases of asthma. Placebo was used in 4 cases of CVA and 10 cases of asthma for comparison with the two therapy groups respectively. Before and after the zafirlucast treatment a series of parameters of DRC were obtained after the methacholine challenge test and were calculated. These included the response threshold (PC35sGaw), the dose-response slope (DRS), the ratio of the area under the curve to the logarithm of the maximal concentration (AUC/1 g[Cmax]), and the maximal response.

RESULTS

Zafirlucast significantly increased the PC35sGaw in the CVA and asthma groups. It conspicuously decreased all the parameters of DRS and AUC/1 g[Cmax] except for maximal response in the cases of CVA, and it had no significant effects on all the parameters of DRS and AUC/1 g[Cmax] except for PC35sGaw in the cases of asthma.

CONCLUSION

Short-term use of Zafirlucast in asthmatic patients could improve the parameters of dose-response curve obtained after the methacholine challenge test.

Reaction of metallotetraphenylporphyrins on hydroxyl-modified silver colloid and Ag2O colloid by surface-enhanced Raman scattering

This paper reports a novel reaction of metallotetraphenylporphyrins on hydroxyl-modified silver colloid and Ag2O colloid. Surface-enhanced Raman spectra of Ag(II) and Cu(II) complexes of tetraphenylporphyrin (TPP) adsorbed on the hydroxyl-modified Ag colloid and Ag2O colloid have been studied. The time-dependent SERS spectra of MTPP (M = Ag, Cu) on hydroxyl-modified Ag colloid were recorded and dramatic change on SERS spectra was observed. The final spectra were found to be strikingly different from the corresponding normal Raman spectra (NRS), with the appearance of new Raman bands at 1614. 1417, 947, 674 and 292 cm(-1). The UV-visible absorption spectrum of MTPP on hydroxyl-modified Ag colloid exhibits a broad shoulder near 460 nm. Similar spectral phenomena were also observed for AgTPP and CuTPP adsorbed on Ag2O colloid. The observed spectral alterations were ascribed to new species formation due to the irreducible oxidation of MTPP on the colloids.

Tibioperoneal (outflow lesion) angioplasty can be used as primary treatment in 235 patients with critical limb ischemia: five-year follow-up

BACKGROUND

In a prospective, nonrandomized, consecutive series of tibioperoneal vessel angioplasty (TPVA), critical limb ischemia (CLI) patients' data were analyzed with regard to immediate and follow-up success.

METHODS AND RESULTS

TPVA was successful in 270 of 284 critically ischemic limbs (95%), with 167 limbs (59%) requiring dilatation of 333 ipsilateral inflow obstructions to access and successfully dilate 486 of 529 (92%) tibioperoneal lesions. A clinical success (relief of rest pain or improvement of lower-extremity blood flow) was attained in 270 limbs at risk (95%). Clinical 5-year follow-up of 215 of 221 successful CLI patients (97%) with 266 successfully revascularized limbs revealed that bypass surgery occurred in 8% and significant amputations in 9% of limbs; 91% of the limbs were salvaged. The cohort's probability of survival was 56%: 58% for Fontaine class III and 33% for class IV patients. Class III compared with class IV patients had significantly (P<0.05) fewer surgical bypasses (3% versus 16%) and amputations: above-knee, 1% versus 4%; below-knee, 3% versus 12%; and transmetatarsal, <1% versus 21%.

CONCLUSIONS

TPVA, often in combination with inflow lesions, is an effective primary treatment for critical limb ischemia. The poor cumulative survival reflects the existence of severe comorbidities, which could potentially be affected by aggressive and effective cardiovascular diagnostic and therapeutic strategies.

[Measurement of the parameters of dose-response curve obtained after the methacholine challenge test]

OBJECTIVE

To investigate the clinical value in the measurement of parameters of the dose-response curve (DRC) obtained after the methacholine challenge test.

METHODS

Twenty-seven cases of cough variant asthma (CVA), 29 of mild asthma, 19 of moderate asthma, and 15 healthy volunteers underwent the methacholine challenge test. The dose-response curves were constructed. The following parameters were calculated: position (PC35sGaw), dose-response curve (DRS), ratio of the area under the curve to the logarithm of the maximal concentration (AUC/lg[Cmax]) and maximal response.

RESULTS

A plateau appeared in 11 cases among the healthy subjects, while a plateau appeared only in 2 cases of CVA and 2 of asthma. There were no significant differences among the asthmatic groups in the measurements of PC35sGaw and AUC/lg[Cmax] (geometric mean PC35sGaw: mild asthmatics = 0.369, moderate asthmatics = 0.251, cough variant asthmatics = 0.547), AUC/lg[Cmax] was significantly greater in the asthmatic groups than in the normal group [AUC/lg [Cmax](mean +/- s): mild asthmatics = 24.7 +/- 4.7, moderate asthmatics = 26.6 +/- 4.3, cough variant asthmatics = 25.6 +/- 3.7, normal subjects = 15.5 +/- 4.3, P < 0.01]. DRS of moderate asthmatics was significantly greater as compared with cough variant asthmatics (geometric mean DRS: mild asthmatics = 30.761, moderate asthma-tics = 59.020, cough variant asthmatics = 19.231, P < 0.05), but there was no difference between the other groups. PC35sGaw was negatively correlated with DRS (r = 0.866, P < 0.001) and with AUC/lg[Cmax] (r = 0.502, P < 0.001).

CONCLUSION

Four parameters of DRC obtained after the methacholine challenge represent airway sensitivity and reactivity respectively. The parameters of DRC of asthmatic patients are different from those of normal subjects. The sensitivity is related to the reactivity, but they are not completely parallel with each other.

TNF-alpha mediates SDF-1 alpha-induced NF-kappa B activation and cytotoxic effects in primary astrocytes

Stromal-derived cell factor-1 alpha (SDF-1 alpha; CXCL12) and its receptor, CXCR4, are constitutively expressed on neuroepithelial cells and are believed to be involved in both development and pathological processes, such as AIDS-associated neurologic disorders. Here, we demonstrate that SDF-1 alpha activates NF-kappa B, stimulates production of chemokines and cytokines, and induces cell death in primary astrocytes, effects that depend on ongoing secretion of TNF-alpha. SDF-1 alpha upregulated TNF-alpha mRNA and protein secretion, as well as TNF receptor 2 expression. TNF-alpha treatment mimicked SDF-1 alpha induction of NF-kappa B, IL-1 alpha/beta, and RANTES, as well as cell death; neutralizing antibodies against TNF-alpha opposed these responses. We also found that SDF-1 alpha activated Erk1 and Erk2 (Erk1/2) MAPK in a biphasic fashion. Early Erk1/2 activation was stimulated directly by SDF-1 alpha and late activation was mediated by TNF-alpha. PD98059 suppression of early Erk1/2 activation correlated with reduction of SDF-1 alpha-induced TNF-alpha expression. Late Erk1/2 activation was involved in TNF-alpha-stimulated NF-kappa B activation and cytokine induction. SDF-1 alpha was induced in reactive CXCR4-positive astrocytes near axotomized spinal cord motor neurons, consistent with autocrine SDF-1/CXCR4 signaling in these cells. We propose that these novel effects of SDF-1 alpha are relevant to the pathogenic and developmental roles of SDF-1 alpha in the CNS.

Giant anharmonicity and nonlinear electron-phonon coupling in MgB2: a combined first-principles calculation and neutron scattering study

First-principles calculations of the electronic band structure and lattice dynamics for the new superconductor MgB (2) are carried out and found to be in excellent agreement with our inelastic neutron scattering measurements. The numerical results reveal that the E(2g) in-plane boron phonons near the zone center are very anharmonic and strongly coupled to the planar B sigma bands near the Fermi level. This giant anharmonicity and nonlinear electron-phonon coupling is key to quantitatively explaining the observed high T(c) and boron isotope effect in MgB (2).

Ultraviolet irradiation blocks cellular responses to transforming growth factor-beta by down-regulating its type-II receptor and inducing Smad7

Transforming growth factor-beta (TGF-beta) is a multi-functional cytokine that regulates cell growth and differentiation. Cellular responses to TGF-beta are mediated through its cell surface receptor complex, which activates transcription factors Smad2 and Smad3. Here we report that UV irradiation of mink lung epithelial cells causes near complete inhibition of TGF-beta-induced Smad2/3-mediated gene expression. UV irradiation inhibited TGF-beta-induced phosphorylation of Smad2 and subsequent nuclear translocation and DNA binding of Smad2/3. Specific cell surface binding of TGF-beta was substantially reduced after UV irradiation. This loss of TGF-beta binding resulted from UV-induced down-regulation of TGF-beta type II receptor (T beta RII) mRNA and protein. UV irradiation significantly inhibited T beta RII promoter reporter constructs, indicating that UV reduction of T beta RII expression involved transcriptional repression. In contrast to its effects on T beta RII, UV irradiation rapidly induced Smad7 mRNA and protein. Smad7 is known to antagonize activation of Smad2/3 and thereby block TGF-beta-dependent gene expression. UV irradiation stimulated Smad7 promoter reporter constructs, indicating that increased Smad7 expression resulted, at least in part, from increased transcription. Overexpression of Smad7 protein to the level induced by UV irradiation inhibited TGF-beta-induced gene expression 30%. Maintaining T beta RII levels by overexpression of T beta RII prevented UV inhibition of TGF-beta responsiveness. Taken together, these data indicate that UV irradiation blocks cellular responsiveness to TGF-beta through two mechanisms that impair TGF-beta receptor function. The primary mechanism is down-regulation of T beta RII, and the secondary mechanism is induction of Smad7.

Safety of three toothbrushes

PURPOSE

To assess the oral soft tissue safety and tolerability of two electric toothbrushes, the Crest Spin Brush and Colgate ActiBrush, and one manual toothbrush, the Oral B 40.

MATERIALS AND METHODS

A total of 104 subjects were enrolled in this single center, randomized, examiner-blind parallel study over a 4-wk test period. Subjects were randomized to treatment and were instructed to brush in their normal manner, twice per day for 60 s. A detailed oral soft tissue examination and interview were conducted by a trained clinician at baseline, 3 days and 4 wks to assess clinical signs and symptoms associated with use of the toothbrushes.

RESULTS

Over the 4-wk period, a total of 19 subjects (18% of the study population) were observed for signs/symptoms. The adverse events were distributed across test groups with 12 subjects in the Oral B 40 group, 4 subjects in the Crest Spin Brush group, and 3 subjects in the Colgate ActiBrush group experiencing at least one adverse event. All adverse events were mild in severity indicating the general safety of all three toothbrushes. The most frequently encountered event was localized gingivitis. The Oral B 40 test group was observed with more adverse events when compared to the Crest Spin Brush and Colgate ActiBrush at 4 wks but not at 3 days. The proportion of subjects experiencing an adverse event in the Crest Spin Brush test group was similar to that of Colgate ActiBrush group. All three toothbrushes were generally well tolerated by subjects enrolled in the study with the Crest Spin Brush and Colgate ActiBrush being the best tolerated.

CLINICAL SIGNIFICANCE

The results of this study indicated that abnormal oral soft tissue findings were distributed among the treatment groups, indicating that daily use of an electric toothbrush is at least as safe as a manual toothbrush.

[The effects of quercetin and isorhamnetin on oxidative modification of VLDL induced by Cu2+]

OBJECTIVE

To observe the effects of quercetin(Que) and isorhamnetin (Iso) on the oxidative modification of very low density lipoprotein (VLDL).

METHODS

Human VLDL was prepared by one-step ultracentrifuge and oxidized by Cu2+ in vitro; Que and Iso in different concentrations were added to VLDL before incubation with Cu2+. The MDA, vitamin E contents and the activity of superoxide dismutase(SOD) in ox-VLDL were determined.

RESULTS

Compared with ox-VLDL group, Que and Iso decreased MDA production in a dependent concentration-manner, Que and Iso also elevated Vit E level and SOD activity markedly.

CONCLUSION

This experiment indicates that Que and Iso have similar inhibitory effects on the oxidative modification of VLDL.

High critical current density and enhanced irreversibility field in superconducting MgB2 thin films

The discovery of superconductivity at 39 K in magnesium diboride offers the possibility of a new class of low-cost, high-performance superconducting materials for magnets and electronic applications. This compound has twice the transition temperature of Nb3Sn and four times that of Nb-Ti alloy, and the vital prerequisite of strongly linked current flow has already been demonstrated. One possible drawback, however, is that the magnetic field at which superconductivity is destroyed is modest. Furthermore, the field which limits the range of practical applications-the irreversibility field H*(T)-is approximately 7 T at liquid helium temperature (4.2 K), significantly lower than about 10 T for Nb-Ti (ref. 6) and approximately 20 T for Nb3Sn (ref. 7). Here we show that MgB2 thin films that are alloyed with oxygen can exhibit a much steeper temperature dependence of H*(T) than is observed in bulk materials, yielding an H* value at 4.2 K greater than 14 T. In addition, very high critical current densities at 4.2 K are achieved: 1 MA cm-2 at 1 T and 105 A cm-2 at 10 T. These results demonstrate that MgB2 has potential for high-field superconducting applications.

Superconductivity in the non-oxide perovskite MgCNi3

The interplay of magnetic interactions, the dimensionality of the crystal structure and electronic correlations in producing superconductivity is one of the dominant themes in the study of the electronic properties of complex materials. Although magnetic interactions and two-dimensional structures were long thought to be detrimental to the formation of a superconducting state, they are actually common features of both the high transition-temperature (Tc) copper oxides and low-Tc material Sr2RuO4, where they appear to be essential contributors to the exotic electronic states of these materials. Here we report that the perovskite-structured compound MgCNi3 is superconducting with a critical temperature of 8 K. This material is the three-dimensional analogue of the LnNi2B2C family of superconductors, which have critical temperatures up to 16 K (ref. 2). The itinerant electrons in both families of materials arise from the partial filling of the nickel d-states, which generally leads to ferromagnetism as is the case in metallic Ni. The high relative proportion of Ni in MgCNi3 suggests that magnetic interactions are important, and the lower Tc of this three-dimensional compound-when compared to the LnNi2B2C family-contrasts with conventional ideas regarding the origins of superconductivity.

Pressure dependence of the superconducting transition temperature of magnesium diboride

We studied the pressure and temperature dependence of the electrical resistivity of the superconducting compound magnesium diboride (MgB(2)). The superconducting transition temperature decreases monotonically with pressure, being parabolic or linear, depending on samples. The rate of decrease under pressure is higher than in conventional superconductors. We discuss our results in terms of the semimetallic character of the electronic band structure of MgB(2).

Loss of superconductivity with the addition of Al to MgB2 and a structural transition in Mg1-x AlxB2

The basic magnetic and electronic properties of most binary compounds have been well known for decades. The recent discovery of superconductivity at 39 K in the simple binary ceramic compound magnesium diboride, MgB2, was therefore surprising. Indeed, this material has been known and structurally characterized since the mid 1950s (ref. 2), and is readily available from chemical suppliers (it is commonly used as a starting material for chemical metathesis reactions). Here we show that the addition of electrons to MgB2, through partial substitution of Al for Mg, results in the loss of superconductivity. Associated with the Al substitution is a subtle but distinct structural transition, reflected in the partial collapse of the spacing between boron layers near an Al content of 10 per cent. This indicates that superconducting MgB2 is poised very near a structural instability at slightly higher electron concentrations.

Strongly linked current flow in polycrystalline forms of the superconductor MgB2

The discovery of superconductivity at 39 K in magnesium diboride, MgB2, raises many issues, a critical one being whether this material resembles a high-temperature copper oxide superconductor or a low-temperature metallic superconductor in terms of its behaviour in strong magnetic fields. Although the copper oxides exhibit very high transition temperatures, their in-field performance is compromized by their large anisotropy, the result of which is to restrict high bulk current densities to a region much less than the full magnetic-field-temperature (H-T) space over which superconductivity is found. Moreover, the weak coupling across grain boundaries makes transport current densities in untextured polycrystalline samples low and strongly sensitive to magnetic field. Here we report that, despite the multiphase, untextured, microscale, subdivided nature of our MgB2 samples, supercurrents flow throughout the material without exhibiting strong sensitivity to weak magnetic fields. Our combined magnetization, magneto-optical, microscopy and X-ray investigations show that the supercurrent density is mostly determined by flux pinning, rather than by the grain boundary connectivity. Our results therefore suggest that this new superconductor class is not compromized by weak-link problems, a conclusion of significance for practical applications if higher temperature analogues of this compound can be discovered.

[Scaling the SF-36 in a Chinese population]

OBJECTIVE

To facilitate the cross-cultural comparison, we employed the principles of fuzzy mathematics in scaling the SF-36 in a Chinese population.

METHODS

We stratified an urban population according to the age, sex, and occupation, and selected 650 people to participate in the study. A total of 646 valid questionnaires were returned. In the 8 domains of the SF-36, the interval estimation of the scores of different alternative answers of 6 domains which have more than 2 alternative answers were conducted.

RESULTS

The fuzzy degrees of most interval estimations were less than 0.5, except 4 estimations in the domain "physical functions". The ordering of the scores of 8 domains was more similar to the original assumption by our scaling criteria than by the US scaling criteria.

CONCLUSION

The scaling criteria set in this study is more suitable for use in Chinese population and we suggest that the alternative answers of the domain "physical functions" be simplified to "yes" and "no".

TNF-alpha down-regulates CXCR4 expression in primary murine astrocytes

CXC chemokine receptor 4 (CXCR4) is a co-receptor for human immunodeficiency virus (HIV) infection and is believed to be involved in the pathogenesis of AIDS-associated neurologic disorders and brain tumors. The physiological roles of CXCR4 in developmental patterning of the nervous and hematopoietic system; gastrointestinal angiogenesis; and cardiac organogenesis were established by studies in gene-targeted mice. Studies on CXCR4 expression and regulation in neuroepithelial cells are fundamental for understanding its physiopathologic roles in the central nervous system (CNS). We show here that CXCR4 expression by primary mouse astrocytes is suppressed by exposure to tumor necrosis factor-alpha (TNF-alpha). TNF-alpha caused a pronounced down-regulation of CXCR4 mRNA in a dose- and time-dependent manner. TNF-alpha-mediated decrease of CXCR4 mRNA accumulation resulted in decreased CXCR4 protein expression. As a result, the ability of stromal cell-derived factor-1alpha (SDF-1alpha) to induce activation of MAP kinases, Erk1/2 was impaired. The half life of CXCR4 mRNA in the presence and absence of TNF-alpha stimulation was comparable, suggesting that TNF-alpha down-regulated CXCR4 mRNA at the transcriptional level. These results suggest that TNF-alpha could modulate HIV and brain tumor pathogenesis and immune-mediated inflammation in the central nervous system (CNS) by regulation of CXCR4 expression.