Primary mediastinal large B-cell lymphoma mimicking liposarcoma

A 78-year-old man consulted for acute exacerbation of chronic obstructive pulmonary disease (COPD) and an incidental finding of an anterior mediastinal tumor on chest radiograph was noted on admission. Chest computed tomography (CT) revealed a fat-containing mediastinal mass with solid component. Mediastinal liposarcoma was the initial diagnosis based on image characteristics but histopathologic examination of the excised tumor revealed lymphoma infiltration of the mediastinal adipose tissue. To our knowledge, this is the first case report of lymphomatous growth in mediastinal lipomatosis.

CTLA-4 gene and susceptibility to human papillomavirus-16-associated cervical squamous cell carcinoma in Taiwanese women

Human papillomavirus (HPV) is considered to be a necessary but not sufficient cause for cervical cancer. The host immunogenetic background plays an important role in the persistence of HPV infection and subsequent development of cervical cancer. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is a molecule expressed mainly on activated T cells and is important in the down-regulation of T-cell activation. The aim of this study was to determine if polymorphisms of the CTLA-4 gene are associated with HPV-induced cervical cancer in Taiwanese women. Polymerase chain reaction-restriction fragment length polymorphism was used to genotype -318 C/T, +49 A/G and CT60 A/G polymorphisms in 144 women with cervical squamous cell carcinoma (CSCC) and 378 ethnicity-matched healthy control women. The presence and genotypes of HPV in CSCC were determined by E6-, E7-based nested polymerase chain reaction. The frequency of C/T genotype of -318 C/T polymorphism was significantly higher in patients with HPV-16-positive CSCC compared with controls (odds ratio = 1.99, 95% confidence interval = 1.16-3.42, P(c) = 0.03). No significant associations were found for +49 A/G and CT60 A/G polymorphisms. Analysis of haplotypes, computationally inferred from genotype data, also revealed no significant differences in distribution among all subjects with CSCC, those with HPV-16-positive CSCC and controls. Our results suggest that the -318 C/T variant in the promoter region of the CTLA-4 gene is associated with HPV-16-associated CSCC in Taiwanese women.

Automated nasopharyngeal carcinoma detection with dynamic gadolinium-enhanced MR imaging

OBJECTIVES

The purpose of this research is to develop an automatic medical diagnosis for segmenting nasopharyngeal carcinoma (NPC) with dynamic gadolinium-enhanced MR imaging.

METHODS

This system is a multistage process, involving motion correction, head mask generation, dynamic MR data quantitative evaluation, rough segmentation, and rough segmentation refinement. Two approaches, a relative signal increase method and a slope method, are proposed for the quantitative evaluation of dynamic MR data.

RESULTS

The NPC detection results obtained using the proposed methods had a rating of 85% in match percent compared with these lesions identified by an experienced radiologist. The match percent for the two proposed methods did not have significant differences. However, the computation cost for the slope method was about twelve times faster than the relative signal increase method.

CONCLUSIONS

The proposed methods can identify the NPC regions quickly and effectively. This system can enhance the performance of clinical diagnosis.

Protein kinase C and changes in manganese superoxide dismutase gene expression in cultured glial cells

1. To study the role of protein kinase C (PKC) in the increase in manganese superoxide dismutase (Mn-SOD) gene expression following transient hypoxia in glial cells, we examined the mRNA levels of Mn-SOD using northern blot analysis. 2. The Mn-SOD mRNA levels were markedly increased after exposure to nitrogen gas for 5 min. 3. Pretreatment with chelerythrine or GF109203x, inhibitors of PKC, attenuated the increase in Mn-SOD mRNA following hypoxia in a concentration-dependent manner. 4. Incubation with phorbol 12-myristate 13-acetate, the PKC activator, enhanced the increase in Mn-SOD gene expression in response to transient hypoxia. 5. The results suggest that hypoxia increases Mn-SOD gene expression in cultured glial cells mainly through activation of a PKC pathway.

Inhibition of nitric oxide synthesis accentuates blood pressure elevation in hyperinsulinemic rats

OBJECTIVES

To examine the role of endogenous nitric oxide (NO) in the pathogenesis of hypertension and insulin resistance in chronic hyperinsulinemic rats.

METHODS

Sustained hyperinsulinemia was achieved by insulin infusion (21.5 pmol/kg per min) via subcutaneous osmotic minipump for 6 weeks. NO synthase inhibitor, Nomega-nitro-L-arginine methyl ester (L-NAME, 5 mg/kg per day) was given orally after 4 weeks of vehicle or insulin infusion. The systolic blood pressure (SBP) was measured under conscious state by an electrosphygmomanometer before and after drug treatments.

RESULTS

Insulin infusion alone significantly increased SBP from 134 +/- 3 to 156 +/- 2 mmHg by week 4 and further to 158 +/- 3 mmHg by week 6 of insulin infusion. The insulin-infused rats had markedly decreased insulin sensitivity, as reflected by an elevated steady-state plasma glucose level estimated by the insulin suppression test. There were no significant differences in plasma glucose and triglyceride levels between rats with and without insulin infusion. When hypertension had been established in rats receiving insulin infusion for 4 weeks, superimposed L-NAME on insulin infusion for additional 2 weeks further increased SBP by 18 +/- 2 mmHg (from 157 +/- 2 to 175 +/- 2 mmHg). Plasma levels of NO metabolites (NOx) significantly decreased from 13.7 +/- 1.1 micromol/l during the control period to 6.1 +/- 0.6 micromol/l after 4 weeks of insulin infusion and further reduced to 4.1 +/- 0.5 micromol/l after combined infusion of L-NAME and insulin. L-NAME treatment alone for 2 weeks in control rats significantly increased SBP by 33 +/- 2 mmHg (from 133 +/- 2 to 166 +/- 2 mmHg) and plasma insulin levels, as a consequence of insulin resistance. Despite marked increases in blood pressure due to infusion of insulin alone or in combination with L-NAME, the sodium balance, urinary sodium and water excretions, water intake and body weight gain of insulin/L-NAME-treated rats were not significantly different from rats without insulin infusion.

CONCLUSIONS

Sustained hyperinsulinemia causes partial impairment of NO production that may contribute to the development of insulin resistance and hypertension. Additional inhibition of NO synthesis by L-NAME accentuates the blood pressure elevation and insulin resistance in hyperinsulinemic rats. Furthermore, a rightward shift of the renal arterial pressure-natriuretic function relationship occurred in this hypertensive model.

In vitro effect of hyperbaric oxygen on the chemolysis of infective stones

BACKGROUND

In order to extend the feasibility of hyperbaric oxygen therapy in the urological field, the present study aimed to investigate the dissolution activity of human infective stones in UROCITRA solution under hyperbaric oxygen condition.

METHODS

The dissolution activity of 7 struvite and 11 mixed struvite and carbonate apatite stones in UROCITRA solution were studied under 2.5 atmosphere (atm) hyperbaric oxygen (HBO) status in a Sigma I N-124 monoplace chamber. Another 7 struvite and 10 mixed struvite and carbonate apatite stones were also studied under normal condition. Chemolysis was performed in a drip device with a 150-ml/hour continuous flow rate.

RESULTS

Under 2.5 atm HBO status, the PO2 of UROCITRA solution was 365 +/- 44 mmHg, which was significantly higher than that of tap water (113 +/- 62 mmHg) and UROCITRA solution (125 +/- 12 mmHg) under normobaric condition (p < 0.001). The decreases in the stone weight of struvite under normobaric condition were 31 +/- 8.8% after 2 h and 48 +/- 15% after 4 h of treatment. The HBO-enriched UROCITRA solution did not increase the dissolution activity as reflected by comparable decreases in the dried stone weight (31.2 +/- 14.6% and 54 +/- 19% at the 2nd and 4th post-treatment hours, respectively, p > 0.05). Similarly, there was no significant difference in the percent stone weight decrease of the mixed struvite and carbonate apatite stones under either HBO or normobaric condition. The dissolution responsiveness of struvite was significantly greater than that of the mixed struvite and carbonate apatite stones.

CONCLUSIONS

The chemolysis of struvite in UROCITRA solution is significantly greater than that of the mixed struvite and carbonate apatite stones. However, the UROCITRA solution enriched with HBO does not enhance the dissolution of infective stones.

Ceramide inhibits lipopolysaccharide-mediated nitric oxide synthase and cyclooxygenase-2 induction in macrophages: effects on protein kinases and transcription factors

The goal of this study was to elucidate whether triggering the sphingomyelin pathway modulates LPS-initiated responses. For this purpose we investigated the effects of N-acetylsphingosine (C(2)-ceramide) on LPS-induced production of NO and PGE(2) in murine RAW 264.7 macrophages and explored the signaling pathways involved. We found that within a range of 10-50 microM, C(2)-ceramide inhibited LPS-elicited NO synthase and cyclooxygenase-2 induction accompanied by a reduction in NO and PGE(2) formation. By contrast, a structural analog of C(2)-ceramide that does not elicit functional activity, C(2)-dihydroceramide, did not affect the LPS response. The nuclear translocation and DNA binding study revealed that ceramide can inhibit LPS-induced NF-kappaB and AP-1 activation. The immunocomplex kinase assay indicated that IkappaB kinase activity stimulated by LPS was inhibited by ceramide, which concomitantly reduced the IkappaBalpha degradation caused by LPS within 1-6 h. In concert with the decreased cytosolic p65 protein level, LPS treatment resulted in rapid nuclear accumulation of NF-kappaB subunit p65 and its association with the cAMP-responsive element binding protein. Ceramide coaddition inhibited all the LPS responses. In addition, LPS-induced PKC and p38 mitogen-activated protein kinase activation were overcome by ceramide. In conclusion, we suggest that ceramide inhibition of LPS-mediated induction of inducible NO synthase and cyclooxygenase-2 is due to reduction of the activation of NF-kappaB and AP-1, which might result from ceramide's inhibition of LPS-stimulated IkappaB kinase, p38 mitogen-activated protein kinase, and protein kinase C.

Neonatal chemical sympathectomy attenuates fructose-induced hypertriglyceridemia and hypertension in rats

Experiments were performed to determine the pathogenic contribution of the peripheral sympathetic nervous system to fructose-induced hypertriglyceridemia, hyperinsulinemia and hypertension in rats. Neonatal chemical sympathectomy was performed in neonatal Sprague-Dawley rats (1-week old) by administration of guanethidine (50 microg/g, i.p.) 5 times per week for consecutive 3 weeks and nerve-intact rats were served as controls. Both groups of rats were fed a fructose-enriched diet for 9 weeks. The systolic blood pressure (SBP) and body weight were measured weekly and arterial blood samples were taken weekly for determinations of plasma insulin, glucose and triglyceride levels. The results showed that fructose feeding for one week significantly increased SBP in intact rats and sympathectomized rats (116+/-1 to 119+/-1 mmHg and 116+/-1 to 120+/-1 mmHg, respectively). SBP further increased thereafter in both groups. However, the increased SBP levels were significantly higher in intact group than in sympathectomized group after 5 weeks of fructose feeding. Fructose feeding for one week concurrently produced hypertriglyceridemia that preceded the appearance of hyperinsulinemia in both groups. The elevated plasma triglyceride levels were significantly lower in sympathectomized rats than in intact rats after 3 weeks of fructose feeding, whereas the elevated plasma insulin concentrations were not different between groups throughout fructose feeding period. Plasma glucose concentrations of both groups were comparable and remained unchanged throughout the study. These data indicate that neonatal chemical sympathectomy attenuated, but did not prevent, fructose-induced elevations in blood pressure and plasma triglyceride levels, suggesting a partial dependency of fructose-induced hypertriglyceridemia and hypertension on the integrity of the peripheral sympathetic nervous system (SNS) in rats.

[Effect of experimental infection with Schistosoma japonicum on the pregnancy of mice]

OBJECTIVE

To understand the effect of Schistosoma infection on the gestation in mice.

METHODS

Female mice infected with Schistosoma japonicum cercariae, and mated with male mice (uninfected) at 40 d and 100 d post-infection, the changes during pregnant period and the growth of offspring were observed until birth. The serum level of estradiol and progesterone of the infected mice was measured by RIA at oestrus.

RESULTS

The level of estradiol and progesterone, and the pregnant rate were much lower in schistosome infected group than that of the control. The rate of abortion, the mortality of pregnant mice and the death rate due to abortion of infected mice increased significantly. The mortality increased with the time of merging male and female mice in one cage prolonged. The body weight and length of the offspring in both infected and control groups were found no significant difference.

CONCLUSION

The results revealed that schistosome infection may suppress estradiol and progesterone secretion, decrease the rate of pregnancy, and that it may also increase the complications and mortality during the gestation periods.

Structural and functional properties of a Bacillus subtilis temperature-sensitive sigma(A) factor

Bacillus subtilis DB1005 is a temperature-sensitive (Ts) sigA mutant containing double-amino-acid substitutions (I198A and I202A) on the hydrophobic face of the promoter -10 binding helix of sigma(A) factor. We have analyzed the structural and functional properties of this mutant sigma(A) factor both in vivo and in vitro. Our data revealed that the Ts sigma(A) factor possessed predominantly a multimeric structure which was prone to aggregation at restrictive temperature. The extensive aggregation of the Ts sigma(A) resulted in a very low core-binding activity of the Ts sigma(A) factor and a markedly reduced sigma(A)-RNA polymerase activity in B. subtilis DB1005, suggesting that extensive aggregation of the Ts sigma(A) is the main trigger for the temperature sensitivity of B. subtilis DB1005. Partial proteolysis, tryptophan fluorescence and 1-anilinonaphthalene-8-sulfonate-binding analyses revealed that the hydrophobic face of the promoter -10 binding helix and also the hydrophobic core region of the Ts sigma(A) factor were readily exposed on the protein surface. This hydrophobic exposure provides an important cue for mutual interaction between molecules of the Ts sigma(A) and allows the formation of multimeric Ts sigma(A). Our results also indicate that Ile-198 and Ile-202 on the hydrophobic face of the promoter -10 binding helix are essential to ensure the correct folding and stabilization of the functional structure of sigma(A) factor.

Pressor and renal effects of intracerebroventricularly administered angiotensins II and III in rats

AIMS

Experiments were performed to assess the effects of intracerebroventricular (ICV) angiotensin (ANG) III on blood pressure and renal function in rats with normal and high sodium intake and to compare these effects with those produced by ICV ANG II.

METHODS

Male Sprague-Dawley rats on a normal sodium (0.3%) diet and a normal sodium diet plus 1% NaCl as drinking water were administered ANG II and ANG III ICV through a chronically implanted cannula. Blood pressure and renal clearance function responses were measured before and during peptide administrations. The effect of ICV ANG III on the renal efferent nerve activity was also evaluated.

RESULTS

ICV injections of ANG II and ANG III at 5 pmol in rats on a normal sodium diet did not significantly alter the blood pressure, but significantly increased renal plasma flow, glomerular filtration rate, urine flow, and absolute and fractional excretions of sodium and potassium. Increased doses of ANG II and III (10, 50 and 100 pmol) significantly increased blood pressure and further enhanced these renal functional indices. Central ANG-III-induced increases in blood pressure and renal functional indices were not significantly different from those produced by ANG II at each corresponding dose. The pressor and renal effects of ANG III were blunted by a specific antagonist, Ile(7)-ANG III. ICV administration of ANG III decreased the renal efferent nerve activity. In rats with dietary NaCl loading, ICV injections of ANG II and III also significantly enhanced renal function.

CONCLUSIONS

Centrally administered ANG III is as potent as ANG II in causing pressor and renal effects in rats on normal and high sodium intake. As ANG II, brain ANG III reduced renal efferent nerve activity which may be partly accounted for the augmented renal function.

Nitric oxide modulates the development and surgical reversal of renovascular hypertension in rats

OBJECTIVE

To evaluate the role of nitric oxide (NO) in the development and unclipping-induced reversal of blood pressure and bilateral renal function in two-kidney, one clip (2K1C) Goldblatt hypertensive rats.

METHODS

Goldblatt hypertensive rats were prepared by clipping the left renal artery 4 weeks before unclipping experiments. NG-nitro-L-arginine methyl ester (L-NAME) was administered after clipping and during unclipping to inhibit nitric oxide (NO) synthesis. Blood pressure and bilateral renal responses were measured.

RESULTS

Chronic L-NAME treatment accelerated and aggravated blood pressure elevations and increased plasma nitrite and nitrate levels in 2K1C rats. Surgical removal of the renal artery clip induced profound reductions in blood pressure in rats with and without L-NAME treatment. However, the magnitude of the unclipping-induced depressor response at the first post-unclipping hour was significantly smaller in L-NAME-treated rats compared to those without L-NAME administration (15 +/- 1 versus 22 +/- 1%, P < 0.05). Two hours after unclipping, blood pressure of both groups fell to a comparable, normal level. Acute intravenous infusion of L-NAME in established 2K1C hypertensive rats further increased blood pressure. Subsequent unclipping caused a depressor response similar to that observed in hypertensive rats treated chronically with L-NAME. Despite the marked decreases in blood pressure, unclipping induced striking increases in glomerular filtration rate (GFR), urine flow and sodium and potassium excretion rates in the ipsilateral kidney. However, the magnitudes of increases in GFR and the diuretic and natriuretic responses in rats without L-NAME treatment were significantly greater than in rats with L-NAME administration. In contrast, unclipping reduced these function indices in the contralateral kidney to a similar level in rats with and without L-NAME treatment.

CONCLUSIONS

NO exerts vasodilator action and thereby lessens renal artery clipping-induced blood pressure elevation. Furthermore, unclipping-induced release of NO partially contributes to the early reduction in blood pressure and changes in bilateral renal function but does not directly mediate the normalization of blood pressure after unclipping in this hypertension model.

Stimulatory effect of trans-cinnamaldehyde on noradrenaline secretion in guinea-pig ileum myenteric nerve terminals

The effect of trans-cinnamaldehyde (CNMA) on the release of noradrenaline (NA) from nerve terminal was investigated using isolated ileal synaptosomes of guinea-pig. Release was determined as the amount of NA, quantified by h.p.l.c.-electrochemical detection, from samples incubated with CNMA minus that in parallel blanks treated with same volume of vehicle. CNMA stimulated the secretion of NA in a concentration-dependent manner from 5 microM to 50 microM, while the value of lactate dehydrogenase in the incubated medium was not influenced by CNMA. However, trans-cinnamic acid, cinnamoyl chloride and cinnamamide failed to produce similar effect. Specific action of CNMA can thus be considered. Guanethidine inhibited the release of NA by CNMA in a concentration- dependent manner. Saxitoxin attenuated the action of CNMA at concentrations sufficient to block sodium channels. The depolarizing effect of CNMA on the membrane potential was also illustrated by a concentration-dependent increase in the fluorescence of bisoxonol, a potential sensitive dye. The NA releasing action of CNMA was deleted by removal of calcium chloride from the bathing medium. This action of CNMA was also attenuated by Rp-cAMP at concentrations sufficient to inhibit the action of cyclic AMP. These findings suggest that CNMA can depolarize the membrane to result in a calcium-dependent and cyclic AMP-related release of NA from noradrenergic terminals.

Hydration of [d(CGC)r(aaa)d(TTTGCG)](2)

We have studied the hydration and dynamics of RNA C2'-OH in a DNA. RNA hybrid chimeric duplex [d(CGC)r(aaa)d(TTTGCG)](2). Long-lived water molecules with correlation time tau(c) larger than 0.3 ns were found close to the RNA adenine H2 and H1' protons in the hybrid segment. A possible long-lived water molecule was also detected close to the methyl group of 7T in the RNA-DNA junction but not to the other two thymine bases (8T and 9T). This result correlates with the structural studies that only DNA residue 7T in the RNA-DNA junction adopts an O4'-endo sugar conformation (intermediate between B-form and A-form), while the other DNA residues including 3C in the DNA-RNA junction, adopt C1'-exo or C2'-endo conformations (in the B-form domain). Based on the NOE cross-peak patterns, we have found that RNA C2'-OH tends to orient toward the O3' direction, forming a possible hydrogen bond with the 3'-phosphate group. The exchange rates for RNA C2'-OH were found to be around 5-20 s(-1), compared to 26.7(+/-13.8) s(-1) reported previously for the other DNA.RNA hybrid duplex. This slow exchange rate may be due to the narrow minor groove width of [d(CGC)r(aaa)d(TTTGCG)](2), which may trap the water molecules and restrict the dynamic motion of hydroxyl protons. The distinct hydration patterns of the RNA adenine H2 and H1' protons and the DNA 7T methyl group in the hybrid segment, as well as the orientation and dynamics of the RNA C2'-OH protons, may provide a molecular basis for further understanding the structure and recognition of DNA.RNA hybrid and chimeric duplexes.

Repaglinide in type 2 diabetes: a 24-week, fixed-dose efficacy and safety study

In this 24-week multicenter, double-blind, randomized, fixed-dose trial, 361 patients having type 2 diabetes received daily preprandial treatment with placebo (n = 75), repaglinide 1 mg (n = 140), or repaglinide 4 mg (n = 146). By a last-observation carried-forward calculation, repaglinide 1 mg or 4 mg treatment decreased mean fasting plasma glucose (FPG) values (by -47 mg/dL or -49 mg/dL) while the placebo group had increased FPG values (by 19 mg/dL). For the repaglinide treatment groups at the end of the study, changes in HbA1c from baseline values ranged from 1.8 to 1.9 percentage points lower than the placebo group. There were no events of severe hypoglycemia. Nearly all hypoglycemic symptom episodes had blood glucose levels above 45 mg/dL. Repaglinide was well tolerated in a preprandial fixed-dose regimen of 1 mg or 4 mg, assigned without adjustment for clinical parameters.

Pharmacokinetics of repaglinide in subjects with renal impairment

OBJECTIVE

To evaluate the effect of renal impairment and renal failure on the pharmacokinetics and safety of repaglinide.

METHODS

We conducted a phase I, multicenter, parallel-group, pharmacokinetic comparison trial with single and multiple doses of repaglinide in subjects with various degrees of renal impairment. Subjects with normal renal function (n = 6) and subjects with renal impairment (mild to moderate, n = 6; severe, n = 6) received treatment with 2 mg repaglinide for 7 days. Subjects in the hemodialysis group (n = 6) received two single doses of 2 mg repaglinide separated by a 7- to 14-day washout period. All subjects had repaglinide serum pharmacokinetic profiles measured for the first and last doses administered. Serum steady-state levels, urine levels, and dialysate levels were also measured.

RESULTS

Pharmacokinetic parameters did not show significant changes after single or multiple doses of repaglinide, although the elimination rate constant in the group with severe renal impairment decreased after 1 week of treatment. Subjects with severe impairment had significantly higher area under the curve values after single and multiple doses of repaglinide than subjects with normal renal function. No significant differences in values for maximum serum concentration or time to reach maximum concentration were detected between subjects with renal impairment and those with normal renal function. Hemodialysis did not significantly affect repaglinide clearance.

CONCLUSIONS

Repaglinide was safe and well tolerated in subjects with varying degrees of renal impairment. Although adjustment of starting doses of repaglinide is not necessary for renal impairment or renal failure, severe impairment may require more care when upward adjustments of dosage are made.

Lack of evidence of association of p21WAF1/CIP1 polymorphism with lung cancer susceptibility and prognosis in Taiwan

An association between the Arg allele of the p21WAF1/CIP1 codon 31 polymorphism and lung cancer has been reported. However, the genotype distribution of the p21 codon 31 polymorphism, as well as the association of this polymorphism with lung cancer risk and prognosis, remain undefined in the Taiwanese population. Therefore, we investigated the genotype distribution of the p21 codon 31 polymorphism in 155 lung cancer patients and 189 non-cancer controls. The genotype frequencies in the Taiwanese non-cancer controls were 0.51 (Ser) and 0.49 (Arg). Chi2 analysis indicated significant differences in Taiwanese genotype distribution of p21 from those reported for Swedes (P=0.001), Caucasians (P=0.001), Indians (P=0.001), and African-Americans (P=0.001). However, our data did not demonstrate an association of the Arg allele of the p21 polymorphism with lung cancer risk in Taiwan. Lung cancer patients with Ser/Arg and Arg/Arg genotypes were at a nonsignificant 1.15-fold increased risk of lung cancer when compared to individuals with the Ser/Ser genotype (95%CI, 0.70-1.86). In addition, although p21 is a downstream target of p53, we found no significant correlation of the p21 polymorphism with the p53 polymorphism and p53 gene mutation in lung cancer patients. We further investigated the association of the p21 polymorphism with prognosis in 154 lung cancer patients. Patients with the Ser/Ser genotype tended to have a poorer prognosis than those with the Ser/Arg and Arg/Arg genotypes (P=0.097, by the log rank test). Our data suggest that the p21 codon 31 polymorphism may not play a significant role in cancer susceptibility and the prognosis of lung cancer patients in Taiwan.

Clinical efficacy and recovery levels of recombinant FVIIa (NovoSeven) in the treatment of intracranial haemorrhage in severe neonatal FVII deficiency

The use of replacement FVII is critical to the successful treatment of life-threatening bleeds in newborns and infants with severe FVII deficiency (<1%). However, the clinical efficacy, optimum dosage and pharmacologic recovery of rFVIIa in such children has not been studied systematically. This report is a case of an infant with severe FVII deficiency (FVII:C at 0%) and massive intracranial haemorrhage in which successful use of rFVIIa (NovoSeven) was carefully monitored. The drug was administered by intravenous bolus through a central line every 4 h at each of three dose levels: 15 microg kg-1, 22 microg kg-1 and 30 microg kg-1. FVII:C was >100% between 30 and 180 min after each infusion with mean trough levels above 25% for all three dose levels. There was no evidence of hyper-coagulation as indicated by measurements of the platelet count, D-dimer, plasma protamine paracoagulant and fibrinogen levels in spite of high FVII:C concentration. In this infant, rFVIIa was well-tolerated, maintained effective haemostasis with good clinical outcome, and produced consistent therapeutic mean trough levels above 25% FVII:C even at 15 microg kg-1 every 4 h.

Changes of superoxide dismutase gene expression and activity in the brain of streptozotocin-induced diabetic rats

In an attempt to discover the changes of superoxide dismutase (SOD) in the brain of diabetic state, we investigated the level of SOD in streptozotocin-induced diabetic rats (STZ-diabetic rats) using enzyme activity assay, Northern blotting analysis of mRNA levels and Western blotting of enzyme amount. Five discrete brain regions, cerebrocortex, hypothalamus, hippocampus, the remaining non-cortex cerebrum (NCC area) and cerebellum, were examined in STZ-diabetic rats to compare with age-matched normal rats. Higher levels of Mn-SOD including the activity, mRNA expression and immunoblot of enzyme were found in all areas of the brain from STZ-diabetic rats as compared with that in Wistar rats. Except in the cerebellum, similar changes of Cu,Zn-SOD were found in the brain of STZ-diabetic rats. These results indicate an increase of SOD both gene expression and activity in the brain of STZ-diabetic rats. This alteration of SOD may be one of the important factors for the vulnerability of the brain to oxygen free radicals or may be related to the pathophysiology of diabetes.

Recurrent inverted papilloma: diagnosis with pharmacokinetic dynamic gadolinium-enhanced MR imaging

BACKGROUND AND PURPOSE

Dynamic gadolinium-enhanced MR imaging has been used successfully to identify post-treatment recurrence or postoperative changes in rectal and cervical carcinoma. Our purpose was to evaluate the usefulness of dynamic gadolinium-enhanced MR imaging for distinguishing recurrent inverted papilloma (IP) from postoperative changes.

METHODS

Fifteen patients with 20 pathologically proved lesions (recurrent IP, 12; fibrosis or granulation tissue, eight) were enrolled in the study. Three observers, blinded to pathologic results, independently evaluated conventional MR images, including T1-weighted (unenhanced and postcontrast), proton-density-weighted, and T2-weighted spin-echo images. Results then were determined by consensus. Dynamic images were obtained using fast spin-echo sequences at 5, 30, 60, 90, 120, 150, 180, and 300 seconds after the injection of gadolinium-diethylene-triamine penta-acetic acid. Time-signal intensity curves of suspected lesions were analyzed by a pharmacokinetic model. The calculated amplitude and tissue distribution time were used to characterize tissue, and their values were displayed as a color-coded overlay.

RESULTS

T2-weighted images yielded a sensitivity of 67%, a specificity of 75%, and an accuracy of 70% in the diagnosis of recurrent IP. Contrast-enhanced T1-weighted images yielded a sensitivity of 75%, a specificity of 50%, and an accuracy of 65%. Pharmacokinetic analysis showed that recurrent IP had faster (distribution time, 41 versus 88 seconds) and higher (amplitude, 2.4 versus 1.2 arbitrary units) enhancement than did fibrosis or granulation tissue. A cut-off of 65 seconds for distribution time and 1.6 units for amplitude yielded a sensitivity of 100% and a specificity of 100% for diagnosing recurrent IP.

CONCLUSION

Dynamic MR imaging can differentiate accurately recurrent IP from postoperative changes and seems to be a valuable diagnostic tool.

Antioxidant status following acute ischemic limb injury: a rabbit model

Although ischemic injury to skeletal muscle is a matter of great clinical importance, relatively little is known about the mechanisms which determine systemic responses. One purpose of this study is to elucidate the systemic antioxidant status following an episode of acute ischemic limb injury and subsequent reperfusion. Twelve New Zealand white rabbits were used in this study. After the animals were anesthetized, an ischemic insult was created in the right hind limb for twelve hours, followed by four hours of reperfusion. Several series of blood samples were obtained. At the end of the experiment, the animals were killed and necropsies undertaken in order to evaluate the antioxidant status of various visceral organs. The results link ischemia and reperfusion injury to a significant decline in antioxidative activity in various tissues. The weakening in antioxidant status after ischemic limb injury was most pronounced in the heart tissue, followed in descending order by the spleen, skeletal muscle, lung, liver, and kidney tissue. The levels of specific antioxidants and reactive oxygen species in various organs changed significantly, and the changes were tissue specific. Endogenous radical scavenging systems were not entirely overwhelmed in most of the tissues studied. But higher levels of malondialdehyde (MDA) found in cardiac tissue suggest that the production of oxygen free radicals is accelerated by an ischemic injury. Based on the study, we believe that the cardiac tissue is particularly susceptible to the effects of ischemia and reperfusion injury. Damage to cardiac tissue is probably the major cause of mortality following acute ischemic injury in a limb.