Role for p27(Kip1) in Vascular Smooth Muscle Cell Migration

BACKGROUND

Rapamycin is a potent inhibitor of smooth muscle cell (SMC) proliferation and migration. Rapamycin-mediated inhibition of SMC proliferation is associated with upregulation of the cyclin-dependent kinase inhibitor p27(Kip1). Previously, we showed that mixed embryonic fibroblasts obtained from p27(Kip1)(-/-) mice were relatively rapamycin-resistant, suggesting that p27(Kip1) plays an integral role in modulating the antiproliferative effects of rapamycin. We hypothesized that the antimigratory effect of rapamycin may also be mediated by p27(Kip1).

METHODS AND RESULTS

Rapamycin (1 to 10 nmol/L) inhibited basic fibroblast growth factor-induced migration of wild-type (WT) but not p27(Kip1)(-/-) SMCs in a dose-dependent manner (P<0.05) in a modified Boyden chamber. The effects of rapamycin on aortic SMC explant migration were also studied with WT, p27(+/-), and p27(-/-) mice. Rapamycin 4 mg. kg(-1). d(-1) IP for 5 days inhibited SMC migration by 90% in the WT and p27(Kip1)(+/-) (P<0.05) but not p27(Kip1)(-/-) animals.

CONCLUSIONS

Lack of p27(Kip1) reduces rapamycin-mediated inhibition of SMC migration. These novel findings suggest a role for p27(Kip1) in the signaling pathway(s) that regulates SMC migration.

Antioxidant activities of trypsin inhibitor, a 33 KDa root storage protein of sweet potato (Ipomoea batatas (L.) Lam cv. Tainong 57)

Trypsin inhibitors (TIs), root storage proteins, were purified from sweet potato (Ipomoea batatas[L.] Lam cv. Tainong 57) roots by trypsin affinity column according to the methods of Hou and Lin (Plant Sci. 1997, 126, 11-19 and Plant Sci. 1997, 128, 151-158). A single band of 33 kDa TI was obtained by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. This purified 33 kDa TI had scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. There was positive correlation between scavenging effects against DPPH (2 to 22%) and amounts of 33 kDa TI (1.92 to 46 pmol). The scavenging activities of 33 kDa TI against DPPH were calculated from linear regression to be about one-third of those of glutathione between 5 and 80 pmol. Using electron paramagnetic resonance (EPR) spectrometry for hydroxyl radical detection, it was found that 33 kDa TI could capture hydroxyl radical, and the intensities of EPR signal were significantly decreased from 1.5 to 6 pmol of 33 kDa TI compared to those of the controls. It is suggested that 33 kDa TI, one of the sweet potato root storage proteins, may play a role as an antioxidant in roots and may be beneficial to health when it is consumed.

Linear accelerator based radiosurgery as a salvage treatment for skull base and intracranial invasion of recurrent nasopharyngeal carcinomas

Nasopharyngeal carcinoma is a common disease entity in Taiwan. It can spread in the prestyloid, retrostyloid compartments, parapharyngeal space, and skull base, and induce paralysis of cranial nerves. We have treated more than 1,500 cases in the past 14 years. Since 1994, we have treated 11 cases of nasopharyngeal carcinomas with skull base invasion by linear accelerator-based stereotactic radiosurgery. There were six male and five female patients. The mean age was 48.4 years. Seven patients had symptoms of low cranial nerves. For these patients, conformal radiotherapy plus brachytherapy was used for the masses beyond the skull base. Stereotactic radiosurgery with a dose of 10 Gy to 19 Gy for one treatment was used for the masses invading the skull base. Eight patients died in follow-up periods from 5 months to 2 years 7 months. Approximately half of patients revealed good response of tumor to radiosurgery. Two patients demonstrated no response of tumors to radiosurgery. Stereotactic radiosurgery may be an adjuvant treatment for recurrent nasopharyngeal carcinomas with skull base and intracranial invasion.

Differential telomerase expression and telomere length in primary intracranial tumors

BACKGROUND

Telomerase activity and telomere length have been shown to be involved in controlling cell proliferation and regulating cell senescence. The authors examined telomerase activity and telomere length in intracranial tumors to determine the clinicopathological behavior of primary intracranial tumors with respect to telomerase expression and alteration of telomere length.

METHODS

Telomerase activity was examined in 139 brain tumor samples. Telomere length was examined in 138 of the 139 samples. These tumors included 61 meningiomas, 27 schwannomas, 19 high-grade neuroepithelial tumors, and 32 low-grade neuroepithelial tumors. Telomerase activity was measured with a telomerase polymerase chain reaction, enzyme-linked immunosolvent assay kit. Telomere length was examined by Southern blot analysis for the terminal restriction fragment length.

RESULTS

Telomerase activity was detected in 39.2% (20/51) of the neuroepithelial tumors. Detection rates were 47.4% (9/19) for anaplastic astrocytomas and glioblastomas and 34.4% (11/32) for low-grade neuroepithelial tumors. However, detectable telomerase activity was found in 30.8% (4/13) of atypical or malignant meningiomas, but was not detected in any schwannomas. There was a highly significant difference in the telomerase detection rate in neuroepithelial or non-neuroepithelial tumors (p = 0.001). Telomere elongation was found in 11.7% (7/60) of all meningiomas, 46.1% (6/13) of atypical or malignant meningiomas, and 14.8% (4/27) of schwannomas. Elongation of telomere length was detected in 12.6% (11/87) of the cases and 23.5% (12/51) in neuroepithelial tumors. This difference was also significant (p < 0.05). Telomere length was reduced in the majority, (75%, 3/4) of malignant or atypical meningiomas with detectable telomerase activity, but only 45% (9/20) of the neuroepithelial tumors.

CONCLUSION

These results indicate that telomerase activation may be a critical step in the pathogenesis of intracranial tumors. Telomere length elongation also indicates a high potential for malignant behavior in these tumors.

Ca2+-dependent and Ca2+-independent excretion modes of salicylic acid in tobacco cell suspension culture

14C-salicylic acid (SA) was used to monitor SA metabolism and its regulation in tobacco cell suspension culture. Two SA concentrations (20 microM and 200 microM) were used for comparison. SA was quickly taken up in both treatments, and the 200 microM-treated cells absorbed approximately 15 times that of 20 microM-treated cells within 5 min. More than 85% and 50% of the absorbed SA were excreted in free form to the culture medium within 5 h from cells treated with 200 microM and 20 microM SA, respectively. SA excretion was significantly inhibited by EGTA and the inhibition could be reversed by the addition of exogenous Ca2+ to the culture medium in the 200 microM SA treatment. However, EGTA had little or no effect on SA excretion in the 20 microM SA treatment. The data suggest that tobacco suspension-cultured cells may contain both Ca2+-dependent and Ca2+-independent pathways for SA excretion. Reduced glutathione (an active oxygen species scavenger), staurosporine (a protein kinase inhibitor), and cycloheximide (an inhibitor of de novo protein synthesis) also blocked intracellular SA excretion to the culture medium in the 200 microM but not in the 20 microM SA treatment. These data support the existence of alternative SA excretion pathways in tobacco suspension-cultured cells. Tobacco cells may use both Ca2+-dependent and Ca2+-independent excretion pathways to cope with different intracellular SA status, and the pathway influenced by EGTA, reduced glutathione, staurosporine, and cycloheximide is activated by SA at 200 microM, but not at 20 microM.

Ca2+-dependent and Ca2+-independent excretion modes of salicylic acid in tobacco cell suspension culture

14C-salicylic acid (SA) was used to monitor SA metabolism and its regulation in tobacco cell suspension culture. Two SA concentrations (20 microM and 200 microM) were used for comparison. SA was quickly taken up in both treatments, and the 200 microM-treated cells absorbed approximately 15 times that of 20 microM-treated cells within 5 min. More than 85% and 50% of the absorbed SA were excreted in free form to the culture medium within 5 h from cells treated with 200 microM and 20 microM SA, respectively. SA excretion was significantly inhibited by EGTA and the inhibition could be reversed by the addition of exogenous Ca2+ to the culture medium in the 200 microM SA treatment. However, EGTA had little or no effect on SA excretion in the 20 microM SA treatment. The data suggest that tobacco suspension-cultured cells may contain both Ca2+-dependent and Ca2+-independent pathways for SA excretion. Reduced glutathione (an active oxygen species scavenger), staurosporine (a protein kinase inhibitor), and cycloheximide (an inhibitor of de novo protein synthesis) also blocked intracellular SA excretion to the culture medium in the 200 microM but not in the 20 microM SA treatment. These data support the existence of alternative SA excretion pathways in tobacco suspension-cultured cells. Tobacco cells may use both Ca2+-dependent and Ca2+-independent excretion pathways to cope with different intracellular SA status, and the pathway influenced by EGTA, reduced glutathione, staurosporine, and cycloheximide is activated by SA at 200 microM, but not at 20 microM.

Hypertensive caudate hemorrhage prognostic predictor, outcome, and role of external ventricular drainage

BACKGROUND AND PURPOSE

The purpose of the present study was to analyze the outcome and outcome predictors of caudate hemorrhage and role of external ventricular drainage in acute hydrocephalus.

METHODS

Clinical data from 36 consecutive patients with hypertensive caudate hemorrhage was used in the present study. Age, gender, volume of parenchymal hematoma, hematoma in the internal capsule, initial Glasgow Coma Scale (GCS), hydrocephalus, severity of intraventricular hemorrhage, and hemorrhagic dilatation of the fourth ventricle were analyzed for effect on outcome. Effect of external ventricle drainage for hydrocephalus was evaluated by comparing preoperative and postoperative GCS scores.

RESULTS

By univariate analyses, poor outcome was associated with a poor initial GCS score (P=0.016), hydrocephalus (P<0.001), intraventricular hemorrhage severity (P<0.01), and hemorrhagic dilatation of the fourth ventricle (P=0.02). By multivariate analysis, stepwise logistic regression revealed that hydrocephalus was the only independent prognostic factor for poor outcome (P<0.001). Postoperative 48-hour GCS score was better than the preoperative score by use of paired-sample t test (P<0.001).

CONCLUSIONS

Hydrocephalus is the most important predictor of poor outcome. External ventricular drainage response for hydrocephalus was good in the present study, whereas an early decision should be made regarding preoperative neurological condition.

8-Nitroxanthine, an Adduct Derived from 2‘-Deoxyguanosine or DNA Reaction with Nitryl Chloride

Activated phagocytic cells generate reactive nitrogen species, including nitryl chloride and peroxynitrite, for host defense against invading pathogens. It has been proposed that these reactive nitrogen species may cause DNA damage and thus contribute to the multistage carcinogenesis process associated with chronic infections and inflammation. Previous studies showed that peroxynitrite reacted with guanine, 2'-deoxyguanosine, or DNA forming 8-nitroguanine. We herein report formation of 8-nitroxanthine as the major nitration product in reactions of 2'-deoxyguanosine or calf thymus DNA with nitryl chloride produced by mixing nitrite with hypochlorous acid, and 8-nitroguanine was a minor product in these reactions. 8-Nitroxanthine was characterized by its NMR and laser desorption ionization mass spectra and by deamination of 8-nitroguanine. Formation of 8-nitroxanthine was also detected by xanthine reaction with various reactive nitrogen species, including nitryl chloride, peroxynitrite, nitronium tetrafluoroborate, and heated nitric and nitrous acid. The identity of 8-nitroxanthine in nitryl chloride-treated dG and DNA was confirmed by co-injection with synthetic 8-nitroxanthine and by its reduction to 8-aminoxanthine. Levels of 8-nitroxanthine and 8-nitroguanine in these reactions were quantified by reversed-phase HPLC with photodiode array detection. Once formed, 8-nitroxanthine was spontaneously removed from DNA with a half-life of 2 h at 37 degrees C and pH 7.4. Therefore, 8-nitroxanthine might be an important DNA lesion derived from reactive nitrogen species in vivo.

Attenuation of tissue P-selectin and MCP-1 expression and intimal proliferation by AT(1) receptor blockade in hyperlipidemic rabbits

Angiotensin-II (Ang-II) participates in the development and progression of atherosclerosis by activating type 1 (AT(1)) receptors. In vitro studies show that inflammatory factors, such as P-selectin and MCP-1, which can be upregulated by Ang-II, play an important role in atherogenesis. We examined the effect of AT(1) receptor blockade with losartan on the expression of P-selectin and MCP-1 in hypercholesterolemic rabbits. Since AT(1) receptor blockade is associated with feedback upregulation of renin-angiotensin system (RAS), we also examined alterations in plasma Ang-II levels by losartan therapy. Male NZW rabbits were fed regular chow (high cholesterol diet or high cholesterol diet + losartan 25 mg/kg/day). As expected, there was a marked intimal proliferation in association with increase in serum cholesterol (P < 0.001). In addition, there was a modest increase in plasma Ang-II levels (P < 0.05), and a significant increase in the expression of AT(1) receptors, P-selectin and MCP-1 in aortas of high cholesterol diet rabbits. Concurrent administration of losartan with high cholesterol diet attenuated aortic intimal proliferation induced a fivefold increase in plasma Ang-II levels and caused a marked decrease in expression of P-selectin and MCP-1 without change in serum lipid levels and aortic AT(1) receptor expression. These observations in hypercholesterolemic animal models show that AT(1) receptor blockade is associated with modulation of P-selectin and MCP-1 expression concurrent with reduction in intimal proliferation. The rise in plasma Ang-II does not appear to limit the potential beneficial effect of losartan.

Early prediction of aphasia outcome in left basal ganglia hemorrhage

OBJECTIVES

The independent predictors of aphasia outcome for patients with left basal ganglia hemorrhage were evaluated.

PATIENTS AND METHODS

We included 140 patients of 1,036 patients with spontaneous intracerebral hemorrhage admitted to our hospital from January 1993 through December 1997. Aphasia was assessed using the aphasia scale of the Scandinavian stroke scale. Univariate and step-wise logistic regression analyses were performed to assess the relationships between the initial aphasia score, age, gender, blood volume, locations of hematoma and aphasia outcome.

RESULTS

Step-wise logistic regression analysis revealed that the following two factors were independently associated with the final aphasia outcome: initial aphasia score (P < 0.0001) and location of hematoma involving the posterior limb of the internal capsule (P = 0.004).

CONCLUSIONS

A particularly high likelihood of poor aphasia outcomes of patients with left basal ganglia hemorrhage are predicted in those who have poor initial aphasia score and whose brain computed tomography shows the hematoma involves the posterior limb of the internal capsule.

Klebsiella brain abscess in adults

BACKGROUND

We analyzed the clinical manifestations and therapeutic outcomes of Klebsiella brain abscesses.

PATIENTS AND METHODS

The clinical data of 15 patients with Klebsiella brain abscesses, retrospectively collected over a 14-year period, were studied.

RESULTS

The 15 patients included 13 cases of Klebsiella pneumoniae infection and two cases of Klebsiella oxytoca. All but one case were community-acquired infections. Locations of all of these abscesses were supratentorial. 12 cases involved a single abscess, and three involved multiple abscesses. Gas formation was also found in two cases (13%). Common predisposing factors included metastatic spread, chronic otitis media and neurosurgical procedures. Among these 15 patients, 11 were treated surgically and four received antibiotics alone. In total, 11 patients survived and four died, with an overall mortality rate of 26.7%.

CONCLUSION

The clinical presentations and therapeutic outcomes varied according to the different Klebsiella species. While debilitating diseases were common in K. pneumoniae infections, they were not common in K. oxytoca infection. And while metastatic septic abscess is a well-known, devastating complication of K. pneumoniae septicemia, usually seen as a brain abscess with a gas-forming appearance, all of these K. oxytoca infections had both otogenic infections and more favorable outcomes.

Reversible bilateral internuclear ophthalmoplegia following head injury

PURPOSE

Internuclear ophthalmoplegia is a syndrome produced by a lesion in the medial longitudinal fasciculus. Head trauma is a rare cause. We describe an unusual case of bilateral internuclear ophthalmoplegia as an isolated sequela following a minor head injury that resolved completely 3 months later.

METHODS

Case report. Magnetic resonance images.

RESULTS

A 34-year-old male developed typical bilateral internuclear ophthalmoplegia after closed head injury. Attempted convergence was normal. Magnetic resonance imaging clearly delineated the focal hemorrhage in the medial longitudinal fasciculus region by showing a small bright lesion in the pontomesencephalic junction in the midline on both T2-weighted and T1-weighted images. The diplopia resolved 4 weeks later. Three months after the accident, his versions were completely normal.

CONCLUSION

Isolated internuclear ophthalmoplegia should be considered in the differential diagnosis when one encounters an adduction deficit in a recently traumatized patient. Magnetic resonance images enhance the ability to correlate the clinical findings with the anatomic lesion.

Hypocomplementemic urticarial vasculitis, jaccoud's arthropathy, valvular heart disease, and reversible tracheal stenosis: a surfeit of syndromes

We describe a patient who, during 29 years of observation, manifested polyarthralgia and polyarthritis leading to progressive deformity of the joints of hands and feet (without loss of cartilage or erosion of bone); persistent urticaria made worse by cold and accompanied by hypocomplementemia; and progressive cardiac valvular disease with mitral and aortic stenosis and regurgitation. In 1996, she developed subglottic tracheal stenosis that resolved by the end of 1997 without a change in treatment, which has consisted of low dose azathioprine, glucocorticoid, and nonsteroidal antiinflammatory drugs. Tests for cryoprecipitable protein, antineutrophil cytoplasmic antibodies, antinuclear antibody, and rheumatoid factor were negative. Skin biopsy was consistent with "leukocytoclastic vasculitis." The pathogenesis of this remarkable combination of syndromes is unknown.

One-stage posterior decompression and fusion using a Luque rod for occipito-cervical instability and neural compression

STUDY DESIGN

Original article.

OBJECTIVE

The authors present seven cases who underwent one-stage suboccipital, C1 and/or C2 posterior decompression and fusion by Luque rod, wiring and autogenic bone graft for occipito-cervical instability and neural compression.

SETTING

Chang Gung University and Medical Center at Kaohsiung, Taiwan.

METHOD

Since January 1996, 20 cases of craniovertebral and upper cervical spinal instability were encountered. Seven of these cases had no neurological improvment under Cone-Barton Skeletal traction. Imaging studies revealed poor reduction with persistent neural compression. One patient underwent unsuccessful anterior trans-oral vertebrectomy for decompression. All patients underwent posterior suboccipital craniectomy, C1 and/or C2 laminectomy for decompression. Contoured Luque rod with wiring and autogeneic bone graft was used for craniocervical fusion. After surgical treatment, halo-vest or sterno-occipito-mandibular immobilizer (SOMI) was used for 3-6 months.

RESULTS

Suboccipital craniectomy and C1 laminectomy could afford a 30-50% increment of anteroposterior diameter in the neural canal and effective decompression of the low medulla and cord. All patients made neurological improvement. The ASIA-MIS scores improved from pre-operative 49 (mean) to 78. Four patients can walk without any support. There were no major complications except for one case requiring readjustment of the halo-vest brace.

CONCLUSION

The authors recommend this procedure as one choice for relieving craniocervical instability with neurological compromise. A programmed rehabilitation will afford better neurological improvement.

Intraspinal osteolipoma. Case report

Lipomatous tumors can contain uncommon or rare components (such as fibrolipoma or angiolipoma) that may result in the development of symptoms. To the best of the authors' knowledge, lipoma associated with an osseous component has not been previously reported. A case of intraspinal extradural tumor composed of both adipose and bone tissue is presented. Current theories on the cause of lipoma with an osseous component are discussed. The tumor was histologically confirmed to be an osteolipoma, and the patient recovered well after resection.

Superior sagittal sinus thrombosis induced by thyrotoxicosis. Case report

There is a wide variety of disorders associated with thrombosis of the superior sagittal sinus (SSS), including infectious disease. noninfectious conditions such as vasculitis and hypercoagulable states, and complications arising from pregnancy or use of oral contraceptive medications. Despite these well-defined associations, approximately 25% of the cases remain idiopathic. In this article the authors describe a patient who was found to have SSS thrombosis while experiencing a thyrotoxic phase of Graves disease. The patient presented with intracerebral hemorrhage, subarachnoid hemorrhage, seizure, coma, a raised fibrinogen concentration, low protein C activity, and atrial fibrillations. Thrombolysis was successfully performed despite the coexistence of thrombosis and intracranial hemorrhage. Patients with thyrotoxicosis and a diffuse goiter may be predisposed to the development of SSS thrombosis, as a result of hypercoagulation and stasis of local venous blood flow. In the present case, a patient in whom thrombosis coexisted with intracranial hemorrhage was successfully treated using thrombolytic therapy.

Chylus-like urine as a complication of percutaneous hyperalimentation catheter in an infant: report of one case

A very low-birth-weight neonate developed chylus-like urine after receiving parenteral nutrition (PN) via percutaneous central venous catheters (CVC) for 7 weeks. A perirenal fluid collection could be seen under sonography. This kind of complication has not been described in literature. After withdrawing the CVC for 5 cm, the urine cleared up. For patients under prolonged PN via CVC and repeated change dressing of the CVC, close monitoring and regular evaluation of the position of the catheter tip are warranted.

Patterns of palmar skin temperature alterations during transthoracic endoscopic T2 sympathectomy for palmar hyperhidrosis

Transthoracic endoscopic T2 sympathectomy has been widely applied to the treatment of a variety of sympathetically mediated disorders. Palmar hyperhidrosis is probably the most common indication for thoracic sympathectomy, especially in certain subtropical areas. Which sympathetic ganglion is to be ablated and how extensive such ablation is enough to eliminate palm sweating are two important issues. Intraoperative monitoring of palmar skin temperature (PST) is the most frequently used method for assessing the accuracy as well as adequacy of ablation of the target sympathetic ganglia. With continuous monitoring of bilateral PST during the operative course of T2 sympathectomy, it was possible to depict the alterations of bilateral PST in response to specific surgical procedures in a real-time manner. For each case, a PST graph was obtained, which represented the graphical expression of intraoperatively recorded bilateral PST data plotted against time. The PST graphs of 93 consecutive cases were analysed. Three types of PST graphs existed, reflecting different responses of bilateral PST to different surgical procedures during the operation. In Type I PST graph pattern, found in 58 cases, skin incision and intercostal muscle dissection caused dramatic bilateral PST drop; and unilateral T2 sympathectomy induced synchronous bilateral PST elevation. Twenty-four cases demonstrated Type II PST graph pattern, in which unilateral T2 sympathectomy caused only ipsilateral PST elevation, although the PST-depressing effect of skin incision and muscle dissection was as significant as in Type I graph pattern. In the 11 cases who showed Type III PST graph pattern, neither skin incision nor T2 sympathectomy induced any apparent changes of PST on either side, giving rise to two rather flat PST curves on the PST graphs. These findings implicate that reciprocal interactions between bilateral sympathetic activities exist in the majority of cases, and that crossover sympathetic modulation may play a role in the neural control of the sudomotor and vasomotor activities of the palms. This study also provides information regarding how PST would possibly change following specific surgical procedures during transthoracic endoscopic T2 sympathectomy, which may be of importance to those who use intraoperative PST monitoring as a guide in determining whether or not the correct sympathetic ganglia are ablated for adequate sympathetic denervation of the palms.

Implication of telomerase activity and alternations of telomere length in the histologic characteristics of intracranial meningiomas

BACKGROUND

Telomerase activity and telomere length have been shown to be involved in the control of cell proliferation and regulation of cell senescence. The expression of telomerase activity may endow cells with the capacity of unlimited proliferation and immortality. The authors examined the telomerase activity and telomere length of intracranial meningiomas to determine the relation between the results and the clinicopathologic behavior of these tumors.

METHODS

Sixty-two specimens of meningiomas including 13 atypical and malignant tumors were used in this study. Telomerase activity was measured with polymerase chain reaction and enzyme-linked immunosolvent assay. Telomere length was measured by detecting the terminal restriction fragments using Southern blots.

RESULTS

Detectable telomerase activity was found in 4 of 13 (30.8%) malignant or atypical meningiomas and only 1 in 49 benign meningiomas (P = 0.006). Elongated telomere length was measured in 6 of 13 (46.1%) patients with malignant or atypical meningiomas and only 1 of 48 (2.1%) in those with benign tumors (P = 0.0002). Three of 4 (75%) of malignant or atypical meningiomas with detectable telomerase activity revealed shortened telomere length, and all tumors with elongated telomere length displayed undetectable telomerase activity. The percentage of malignant or atypical meningiomas with detectable telomerase activity or elongated telomere were significantly higher (76.9%) than that of benign tumors (4.0%). The proliferative index was calculated as the percentage of tumor cell nuclei immunoreactive for Ki-67 to total tumor nuclei. The mean values of proliferative index in benign, atypical, and malignant meningiomas were 1.2, 11.0, and 30.0, respectively.

CONCLUSIONS

The results indicate that telomerase activation may be a critical step in the pathogenesis of malignant or atypical meningioma. Elongation of the telomere length also implicates the high potential for malignant behavior in these tumors.

Mice deficient in hepsin, a serine protease, exhibit normal embryogenesis and unchanged hepatocyte regeneration ability

Hepsin, a liver-enriched novel serine protease, has been implicated in participating with normal cell growth, embryogenesis, and blood coagulation pathway. To study its function in vivo, we have disrupted the mouse hepsin gene by homologous recombination. Targeted disruption of the hepsin gene and ablation of hepsin message were demonstrated by Southern blotting, Northern blotting and RT-PCR analysis. Homozygous hepsin -/- mice were viable, fertile, and exhibited no gross abnormalities, as judged by the size, weight and blood coagulation (PT) assays. However, the serum concentration of the bone form of alkaline phosphatase, aspartate aminotransferase, and alanine aminotransferase of the hepsin -/- mice was mildly elevated, in spite of no obvious pathological change of hepatocytes. To examine whether hepsin is involved in controlling cell growth in adult tissues, 70% hepatectomy was applied to the hepsin -/- mice. Liver regeneration proceeded normally in the hepsin -/- mice as judged by the liver mass restoration rate. These results suggest that loss of hepsin function causes no effect in cell growth and embryogenesis in vivo, which is in contradiction to the studies using in vitro cell culturing system. Moreover, gross mass regeneration of liver after damage proceeds normally in the absence of functional hepsin.

Elevated levels of plasma C-reactive protein are associated with decreased graft survival in cardiac transplant recipients

BACKGROUND

Inflammation may be involved in the origin of transplant coronary artery disease. We hypothesized that plasma levels of C-reactive protein (CRP) and interleukin-6 (IL-6), markers for systemic inflammation, would correlate with cardiac transplant graft survival.

METHODS AND RESULTS

We studied 99 consecutive cardiac transplant recipients who were referred for routine endomyocardial biopsy and/or surveillance coronary angiography. Plasma levels of CRP and IL-6 were measured by their respective ELISAs. Patients were divided into 2 groups: those who died or required retransplantation and those who survived without the need for retransplantation. During the follow-up period of 5.0+/-2.7 years (range, 0.2 to 15.1 years) after transplant, 20 patients died and 9 required retransplantation. There was no significant difference in age, race, sex, cause of native myopathy, presence of diabetes, or use of aspirin, statins, or calcium channel blockers between the 2 groups. Although IL-6 did not relate to graft failure, CRP level was predictive of allograft failure (P:=0.003). The risk of allograft failure increased 36% for every 2-fold increase in CRP level. Moreover, CRP levels also correlated significantly with the frequency of grade 3 rejection (P:=0.02). In multivariate analysis, when combined with other significant predictors such as donor age and sex mismatching of the graft, CRP still significantly predicted graft failure (P:=0.025) with a 32% increase in the risk of graft failure for every 2-fold increase in CRP level.

CONCLUSIONS

These findings suggest that elevated plasma levels of CRP are associated with subsequent allograft failure in cardiac transplant recipients.

Urinary uric acid/creatinine ratio as an additional marker of perinatal asphyxia

PURPOSE

To study the validity of urinary uric acid (UA) as a marker of perinatal asphyxia in term and premature infants.

METHODS

The urinary ratio of UA to creatinine (Cr) was obtained within 24 hours after birth in four groups of infants: 17 term infants and 18 premature infants with perinatal asphyxia, and 22 healthy term infants and 20 premature infants without perinatal asphyxia. Perinatal asphyxia was defined as an Apgar score of 3 or less at 1 minute or 5 or less at 5 minutes, and/or a first blood gas pH of less than 7.25 and a base deficit of at least 12 mmol/L.

RESULTS

The urinary ratio of UA to Cr was significantly higher in term infants with perinatal asphyxia than in term infants without asphyxia (1.53 +/- 0.71 vs 0.73 +/- 0.45; p < 0.005). The same result was found between premature infants with and without perinatal asphyxia (3.89 +/- 1.84 vs 2.45 +/- 0.88; p < 0.01). The urinary ratio of UA to Cr in premature infants was significantly higher than in term infants. When the urinary ratio of UA to Cr was greater than 0.95, perinatal asphyxia was identified with a sensitivity of 80% and a specificity of 71% in term infants. In premature infants, a cut-off value of UA/Cr for perinatal asphyxia of 2.9 had a sensitivity of 71% and a specificity of 70%.

CONCLUSIONS

The results of this study indicate that the urinary ratio of UA to Cr may be used as an additional marker of perinatal asphyxia in term and premature infants. In comparison with other markers such as xanthine, hypoxanthine, and ascorbic acid, it is a simple, quick, and inexpensive way to detect hypoxic episodes in a neonatal intensive care unit within 24 hours after birth.

Classification of some active compounds and their inactive analogues using two three-dimensional molecular descriptors derived from computation of three-dimensional convex hulls for structures theoretically generated for them

Two three-dimensional (3D) molecular descriptors are used to classify 73 protease inhibitors against the human immunodeficiency virus type 1 (HIV-1). X-ray structures of these HIV-1 protease bound inhibitors are used as templates to generate the most probable bioactive conformations of the inhibitors. A convex hull computation algorithm is applied to each structure generated. The frequency of atoms lying on the vertexes of each hull is counted. Vertexes of the same atomic charge state are then gathered together as a set of commonly exposed groups for all the structures generated. The first 3D descriptor is computed as the maximum molecular path length among any three distinct commonly exposed groups, while the second 3D one is computed as the maximum molecular path length among any three atoms of nonconvex hull vertexes. We find that the 73 HIV-1 protease inhibitors can be classified by the first 3D descriptor into two groups, which agrees with the result of visual classification using the activity data as a criterion for these compounds. The classification scheme is then used to classify a database of 427 active trypsin inhibitors and their inactive analogues. The structures of these compounds are generated theoretically from steps of energy minimization and molecular dynamics. Classification for all these compounds is performed using the SYBYL hierarchical clustering method on the first 3D descriptor and then the second 3D one computed. It is found that some inactive analogues are completely separated from the active inhibitors at the first stage of classification using the first 3D descriptor. Most of the highly active inhibitors are classified into a cluster at the second stage of classification using the second 3D descriptor. Finally, most of these highly active inhibitors are separated from all the accompanying inactive analogues in the cluster through a structural alignment process using a set of commonly exposed groups determined for them.