Mechanism of FK506-induced renal hypoperfusion and its reversion in rats

AIM

To investigate the mechanism of renal hypoperfusion induced by tacrolimus (FK506) and to test the related agents acting against the process.

METHODS

Experiments were performed in 6 groups of isolated perfused rat kidneys (IPRK). The parameters of renal function and the concentration of endothelin in the perfusate and urine were assessed at an interval of 15 min. Four groups of IPRK were perfused with normal saline and varied concentrations of FK506 (10 nmol/L-10 micromol/L) to set up a control and a hypoperfusion model. The other 2 groups were used as hypoperfusion models to test the actions of endothelin receptor antagonist FR139317 and calcium channel blocker diltiazem.

RESULTS

Hypoperfusion model was established in IPRK by adding FK506 10 micromol/L in the perfusate, with the significant decreases of perfusate flow rate (PFR) and glomerular filtration rate (GFR), the significant increase of perfusion resistance (PR) and the concomitant increase of endothelin in perfusate and urine (P < 0.01). When FR139317 was added into the perfusate, only the depressed GFR was improved (P < 0.05) while the increased PR was not (P > 0.05). However, the addition of diltiazem reversed both the increase of PR and the decrease of GFR completely (P < 0.01).

CONCLUSION

Endothelin is likely to play an important role in the pathogenesis of FK506-induced acute renal hypoperfusion. Diltiazem can completely prevent the renal hypoperfusion induced by FK506 in IPRK.

An in vitro system to examine the effective phospholipids and structural domain for protein targeting to seed oil bodies

An in vitro system was established to examine the targeting of proteins to maturing seed oil bodies. Oleosin, the most abundant structural protein, and caleosin, a newly identified minor constituent in seed oil bodies, were translated in a reticulocyte lysate system and simultaneously incubated with artificial oil emulsions composed of triacylglycerol and phospholipid. The results suggest that oil body proteins could spontaneously target to artificial oil emulsions in a co-translational mode. Incorporation of oleosin to artificial oil emulsions extensively protected a fragment of approximately 8 kDa from proteinase K digestion. In a competition experiment, in vitro translated caleosin and oleosin preferentially target to artificial oil emulsions instead of microsomal membranes. In oil emulsions with neutral phospholipids, relatively low protein targeting efficiency was observed. The targeting efficiency was substantially elevated when negatively charged phospholipids were supplemented to oil emulsions to mimic the native phospholipid composition of oil bodies. Mutated caleosin lacking various structural domains or subdomains was examined for its in vitro targeting efficiency. The results indicate that the subdomain comprising the proline knot motif is crucial for caleosin targeting to oil bodies. A model of direct targeting of oil-body proteins to maturing oil bodies is proposed.

Measurement of J/psi production in continuum e(+)e(-) annihilations near square root of s = 10.6 GeV

The production of J/psi mesons in continuum e(+)e(-) annihilations has been studied with the BABAR detector at energies near the Upsilon(4S) resonance. The mesons are distinguished from J/psi production in B decays through their center-of-mass momentum and energy. We measure the cross section e(+)e(-)-->J/psi X to be 2.52+/-0.21+/-0.21 pb. We set a 90% C.L. upper limit on the branching fraction for direct Upsilon(4S)-->J/psi X decays at 4.7 x 10(-4).

Sharing Pacific-Rim experiences in disasters: summary and action plan

INTRODUCTION

The discussions in this theme provided an opportunity to address the unique hazards facing the Pacific Rim.

METHODS

Details of the methods used are provided in the preceding paper. The chairs moderated all presentations and produced a summary that was presented to an assembly of all of the delegates. Since the findings from the Theme 3 and Theme 7 groups were similar, the chairs of both groups presided over one workshop that resulted in the generation of a set of action plans that then were reported to the collective group of all delegates.

RESULTS

The main points developed during the presentations and discussion included: (1) communication, (2) coordination, (3) advance planning and risk assessment, and (4) resources and knowledge.

DISCUSSION

Action plans were summarized in the following ideas: (1) plan disaster responses including the different types, identification of hazards, focusing training based on experiences, and provision of public education; (2) improve coordination and control; (3) maintain communications, assuming infrastructure breakdown; (4) maximize mitigation through standardized evaluations, the creation of a legal framework, and recognition of advocacy and public participation; and (5) provide resources and knowledge through access to existing therapies, the media, and increasing and decentralizing hospital inventories.

CONCLUSIONS

The problems in the Asia-Pacific rim are little different from those encountered elsewhere in the world. They should be addressed in common with the rest of the world.

Measurement of the decays B--> phiK and B--> phiK*

We have observed the decays B--> phiK and phiK(*) in a sample of over 45 million B mesons collected with the BABAR detector at the PEP-II collider. The measured branching fractions are B(B+--> phiK+) = (7.7(+1.6)(-1.4)+/-0.8)x10(-6), B(B0--> phiK0) = (8.1(+3.1)(-2.5)+/-0.8)x10(-6), B(B+--> phiK(*+)) = (9.7(+4.2)(-3.4)+/-1.7)x10(-6), and B(B0--> phiK(*0)) = (8.7(+2.5)(-2.1)+/-1.1)x10(-6). We also report the upper limit B(B+--> phipi(+))<1.4x10(-6) ( 90% C.L.).

Measurement of branching fractions and search for CP-violating charge asymmetries in charmless two-body B decays into pions and kaons

We present measurements, based on a sample of approximately 23x10(6) BB pairs, of the branching fractions and a search for CP-violating charge asymmetries in charmless hadronic decays of B mesons into two-body final states of kaons and pions. We find the branching fractions B(B0-->pi(+)pi(-)) = (4.1+/-1.0+/-0.7)x10(-6), B(B0-->K+pi(-)) = (16.7+/-1.6+/-1.3)x10(-6), B(B+-->K+pi(0)) = (10.8(+2.1)(-1.9)+/-1.0)x10(-6), B(B+-->K0pi(+)) = (18.2(+3.3)(-3.0)+/-2.0)x10(-6), B(B0-->K0pi(0)) = (8.2(+3.1)(-2.7)+/-1.2)x10(-6). We also report 90% confidence level upper limits for B meson decays to the pi(+)pi(0), K+K-, and K0K+ final states. In addition, charge asymmetries have been found to be consistent with zero, where the statistical precision is in the range of +/-0.10 to +/-0.18, depending on the decay mode.

Optimized protocols in terms of equalizing the true and accidental coincidences of each bed position in static multiple bed position carbon-11 PET studies and a target single bed position study

Quantitative carbon-11 (11C) positron emission tomography (PET) is gaining more attention in oncological applications. In addition, it was discovered that accidental coincidences (randoms) can play an important role in studies such as partial volume effects correction without needing to use anatomical information. However, because of the short half-life of 11C, a homogeneous multiple bed position 11C image is hard to obtain. This study aimed to determine whether innovative pseudogating, optimized pseudogating and optimized double-up methods could match the true counts and randoms to each bed position and to a target single bed position study. A long cylindrical phantom filled with [11C]acetate was scanned by a dedicated PET scanner using six protocols: whole body, frame-duration-compensated whole body, double-up, optimized double-up, pseudogating, and optimized pseudogating. The differences between the protocols are in the initial activity, frame duration and frame number for each bed position. The parameters for pseudogating were determined according to the theory that true counts and randoms are proportional to the radioactivity and its square, respectively. The results show that the stated goals could only be achieved by pseudogating and optimized pseudogating. We conclude that pseudogating or optimized pseudogating must be applied for a critical quantitative study. However, optimized double-up and double-up methods are good alternatives for semi-quantitative and qualitative studies, respectively.

FtsQ, FtsL and FtsI require FtsK, but not FtsN, for co-localization with FtsZ during Escherichia coli cell division

During cell division in Gram-negative bacteria, the cell envelope invaginates and constricts at the septum, eventually severing the cell into two compartments, and separating the replicated genetic materials. In Escherichia coli, at least nine essential gene products participate directly in septum formation: FtsA, FtsI, FtsL, FtsK, FtsN, FtsQ, FtsW, FtsZ and ZipA. All nine proteins have been localized to the septal ring, an equatorial ring structure at the division site. We used translational fusions to green fluorescent protein (GFP) to demonstrate that FtsQ, FtsL and FtsI localize to potential division sites in filamentous cells depleted of FtsN, but not in those depleted of FtsK. We also constructed translational fusions of FtsZ, FtsA, FtsQ, FtsL and FtsI to enhanced cyan or yellow fluorescent protein (ECFP or EYFP respectively), GFP variants with different fluorescence spectra. Examination of cells expressing different combinations of the fusions indicated that FtsA, FtsQ, FtsL and FtsI co-localize with FtsZ in filaments depleted of FtsN. These localization results support the model that E. coli cell division proteins assemble sequentially as a multimeric complex at the division site: first FtsZ, then FtsA and ZipA independently of each other, followed successively by FtsK, FtsQ, FtsL, FtsW, FtsI and FtsN.

[The effect of Beijing Fangshan Cardiovascular Prevention Program on the incidence and mortality of stroke]

OBJECTIVE

To explore potential effective measures for lowering incidence and mortality of stroke in rural community population of China.

METHODS

Beijing Fangshan Cardiovascular Prevention Program (BFCP), under whole population and high risk individuals strategies with measures of health education and hypertension control, were launched in 1991 in five communities including intervention communities (IC), about 66,000 residents, and control communities (CC), about 54,000 residents, in Fangshan, Beijing suburb.

RESULT

Incidences of stroke averaged 235.23 per 100,000 and 289.22 per 100,000, for IC and CC respectively, with a statistically significant difference, and mortalities of stroke averaged 80.63 per 100,000 and 98.01 per 100,000, for IC and CC respectively, with a statistically significant difference, during years of 1992 to 1999. The net change of stroke incidence was 126.13 per 100,000 in IC versus CC, with a statistically significant difference. Incidences of stroke increased by 11.63% and 75.27%, for IC and CC respectively, while mortalities of stroke decreased by 46.80% and 22.82%, respectively, for IC and CC from years of 1992 to 1999.

CONCLUSION

BFCP has yielded obvious effect on controlling incidence and mortality of stroke in rural community population, but the trend of stroke incidence increasing was still not restrained radically.

Effect of norcantharidin on N-acetyltransferase activity in HepG2 cells

The inhibition ofarylamine N-acetyltransferase (NAT) activity by norcantharidin (NCTD), the demethylated form of cantharidin, in human hepatocellular carcinoma HepG2 cells was investigated. By using high performance liquid chromatography, NAT activity on acetylation of 2-aminofluorene (AF) and p-aminobenzoic acid (PABA) were examined. Two assay systems were performed, one with cellular cytosols, the other with intact HepG2 cell suspensions. The NAT activity in HepG2 cell line was inhibited by norcantharidin in a dose-dependent manner in both types of examined systems: i.e. the greater the concentration of norcantharidin in the reaction, the greater the inhibition of NAT activities. This report is the first to show that norcantharidin has an inhibitory effect on NAT activity in HepG2 cell.

Effects of Ginsenoside Rb2 and Rc on inferior human sperm motility in vitro

The purpose of the study was to investigate the effects of two constituents of Panax notoginseng flower extract, Ginsenoside Rb2 and Rc, on human sperm motility and progression in vitro. Semen samples were collected from 20 patients with sperm motility between 20% and 40% of normal. All samples had sperm counts of over 20 million per milliliter, in accordance with the World Health Organization standard. Sperm were separated by a Percoll discontinuous gradient technique, and divided into a Percoll sperm control group, and three Ginsenoside Rb2 experimental groups (0.1, 0.01 and 0.001 mg/ml) and three Ginsenoside Rc experimental groups (0.1, 0.01 and 0.001 mg/ml). The results showed that at concentrations of 0.01 mg/ml and 0.001 mg/ml, Ginsenoside Rc enhanced both sperm motility and sperm progression significantly at the end of the 1st and 2nd hour. However, the three concentrations of Ginsenoside Rb2 did not increase sperm motility at the 1st or 2nd hour, but promoted sperm progression at the 2nd hour, when compared to the Percoll group.

Observation of CP violation in the B(0) meson system

We present an updated measurement of time-dependent CP-violating asymmetries in neutral B decays with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. This result uses an additional sample of Upsilon(4S) decays collected in 2001, bringing the data available to 32 x 10(6) BB macro pairs. We select events in which one neutral B meson is fully reconstructed in a final state containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2 beta, is derived from the decay time distributions in such events. The result sin2 beta = 0.59+/-0.14(stat)+/-0.05(syst) establishes CP violation in the B(0) meson system. We also determine absolute value of lambda = 0.93+/-0.09(stat)+/-0.03(syst), consistent with no direct CP violation.

Photodynamic Therapy for Patients with Advanced Non–Small-Cell Carcinoma of the Lung

Patients with advanced non-small-cell lung carcinoma (NSCLC) have poor prognoses and experience negative sequelae of disease. Patients often suffer from dyspnea and/or hemoptysis, with overall pulmonary compromise. Patients with advanced, inoperable disease have limited options for treatment. This study summarizes our early experience and findings using photodynamic therapy (PDT) as an effective modality in the palliation of hemoptysis, dyspnea, and physical airway obstruction in cases of inoperable lung cancer. A retrospective review was conducted for the first 10 patients diagnosed with stage III/IV obstructive NSCLC who underwent PDT at our institution. Endobronchial lesions were identified by bronchoscopy. Treatments were initiated 48 hours after intravenous injection of 2 mg/kg of the photosensitizing agent porfimer sodium (Photofrin, QLT PhotoTherapeutics, Vancouver, BC). The porfimer sodium was then activated by illumination with a 630 nm wavelength light using a Coherent argon ion laser through a flexible bronchoscope. Repeated bronchoscopies were performed 1-3 days following initial PDT for evaluation and airway debridement. In 8 cases, a second treatment of PDT was administered within 72 hours of the first injection. One patient received a third treatment several months later. Three patients also received endobronchial stents after PDT. Overall, all 10 patients responded to PDT. Physical airway obstruction was reduced in all patients, with a noted improvement in bronchoscopic luminal diameter. Acute hemoptysis resolved in all 7 symptomatic patients. Median survival was 5.5 months post-PDT, while median survival postdiagnosis was 10.5 months. Three patients are alive at the time of this review at 5-21 months following therapy. Patients with unresectable late-stage NSCLC have few options for treatment. Our early experience with PDT indicates effective relief of hemoptysis, dyspnea, and airway obstruction and improves their quality of life.

Electrocatalytic cyclization of dithiothreitol on a chemically modified electrode by analogy with protein action

Electrocatalytic oxidative cyclization of dithiothreitol (DTT(SH)2) to a disulfide product was demonstrated on a Nafion/lead-ruthenium oxide pyrochlore chemically modified electrode (NPyCME). The process at the NPyCME with DTT(SH)2 is similar to the behaviour of protein in a disulfide linkage, which can be demonstrated by product analysis using HPLC coupled with UV spectroscopy. A possible electrocatalytic mechanism for DTT(SH)2 oxidation to dihydroxydithiane [i.e. cyclized DTT(S-S)] on the NPyCME was proposed in terms of Py-Ru(IV)/Py-Ru(VI) redox active sites. This physical aspect was further utilized for high precision analytical assays using flow injection analysis (FIA), with a linearity up to 50 microM and a detection limit (S/N = 3) of 28 nM (8.64 pg) in a 20 microL sample loop. This is the most sensitive method ever reported for DTT(SH)2 detection assays. The interference from dissolved oxygen, disulfide and glucose is almost negligible. The present method offers an easy route for extension to redox-related protein studies.

Cryopreservation of gander semen

1. The effect of dimethylacetamide (DMA) and dimethyl sulphoxide (DMSO) on the cryopreservation of gander semen were investigated. An improved survival rate of spermatozoa after freeze-thawing was obtained when semen was frozen by a fast-freezing procedure on dry ice with 9% DMA as the cryoprotectant. 2. Gander semen, which was frozen during mid season, was tested for fertilising ability in different times of the season. The percentage of fertility during d 3 to d 9 after 2 consecutive inseminations was 68% to 95%, depending on the date of artificial insemination.

Adrenal insufficiency in critically ill emergency department patients: a Taiwan preliminary study

OBJECTIVE

Unrecognized adrenal insufficiency can have serious consequences in critically ill emergency department (ED) patients. This prospective pilot study of adrenal function in patients with severe illness was undertaken to determine the prevalence of adrenal dysfunction and any relation to prior herbal drug use.

METHODS

In a high-volume urban tertiary care ED, adult patients with sepsis or acute myocardial infarction (AMI) were eligible for the study. Over a two-month period, a convenience sample was enrolled by the authors on arrival to the ED. Inclusion criteria were systemic inflammatory response syndrome (SIRS) criteria plus evidence of at least one organ dysfunction or cardiac marker plus electrocardiogram-proven AMI. Exclusion criteria included known corticosteroid use. Serum cortisol was measured on arrival and for those patients with a level of <15 microg/dL (<414 nmol/L), an adrenocorticotropic hormone (ACTH) stimulation test was performed.

RESULTS

Of the 30 enrolled patients, 23 (77%) were suffering from severe sepsis and the other seven (23%) had an AMI. Thirteen of the 30 patients (43%; 95% CI = 25% to 65%) had serum cortisol levels of <15 microg/dL, consistent with adrenal insufficiency, nine with severe sepsis and four with an AMI. Eight (62%; 95% CI = 32% to 86%) of the 13 patients with low cortisol levels reported using herbal medications, while only two (12%; 95% CI = 1% to 36%) of the 17 with normal cortisol levels reported taking herb drugs (p = 0.01). Only two (15%; 95% CI = 2% to 45%) of the patients with low cortisol levels failed their corticotropin stimulation test, suggestive of true adrenocortical insufficiency. Both reported using herbal preparations.

CONCLUSIONS

These results indicate that adrenal dysfunction is common among a group of critically ill patients seen in this Taiwanese ED. Moreover, the use of herbal drugs was high in the patients with low serum cortisols. Further studies are required to both confirm these findings and clarify whether a number of herbal medications contain corticosteroids.

Two upstream enhancers collaborate to regulate the spatial patterning and timing of MyoD transcription during mouse development

MyoD is a member of the basic-helix-loop-helix (bHLH) transcription factor family, which regulates muscle determination and differentiation in vertebrates. While it is now well established that the MyoD gene is regulated by Sonic hedgehog, Wnts, and other signals, it is not known how MyoD transcription is initiated and maintained in response to these signals. We have investigated the cis control of MyoD expression to identify and characterize the DNA targets that mediate MyoD transcription in embryos. By monitoring lacZ reporter gene expression in transgenic mice, we show that regulatory information contained in 24 kb of human MyoD 5' flanking sequence is sufficient to accurately control MyoD expression in embryos. Previous studies have identified two muscle-specific regulatory regions upstream of MyoD, a 4-kb region centered at -20 kb (designated fragment 3) that contains a highly conserved 258-bp core enhancer sequence, and a more proximal enhancer at -5 kb, termed the distal regulatory region (DRR), that heretofore has been identified only in mice. Here, we identify DRR-related sequences in humans and show that DRR function is conserved in humans and mice. In addition, transcriptional activity of MyoD 5' flanking sequences in somites and limb buds is largely a composite of the individual specificities of the two enhancers. Deletion of fragment 3 resulted in dramatic but temporary expression defects in the hypaxial myotome and limb buds, suggesting that this regulatory region is essential for proper temporal and spatial patterning of MyoD expression. These data indicate that regulatory sequences in fragment 3 are important targets of embryonic signaling required for the initiation of MyoD expression.

Effect of N(G)-nitro-L-arginine methyl ester on intestinal permeability following intestinal ischemia-reperfusion injury in a rat model

Subclinical intestinal ischemia-reperfusion injury (IRI) causes an increase in mucosal permeability and may represent an early event in the pathogenesis of necrotizing enterocolitis in premature infants. Previous studies suggested that continuous, endogenous formation of nitric oxide (NO) maintains the mucosal integrity of the intestine, thus protecting the gut from injuries from blood-borne toxins and tissue-destructive mediators. This study was undertaken to assess whether the inhibition of NO production causes an increase in intestinal permeability in rats following IRI. Sprague-Dawley rats weighing 200-300 g were divided into 4 groups: (1) untreated group (normal control); (2) ischemia-reperfusion group; (3) early N(G)-nitro-L-arginine methyl ester (L-NAME), a specific inhibitor of NO production, treatment group, and (4) late L-NAME treatment group. Transient IRI was induced by 30-min occlusion, followed by reperfusion of the isolated ileal loop. The L-NAME was administered 15 min before and after mesenteric ischemia as a 25-mg/kg bolus. Fluorescein isothiocyanate-dextran (FITC-D) was used to quantitatively assess the alteration in mucosal permeability of the intestine. There was no significant increase in the portal vein FITC-D level among normal controls, ischemia-reperfusion group and late L-NAME-treated group, but there was an approximately 6-fold increase in the early L-NAME treatment group. The pathological features of the intestine following IRI include denudation of the villus epithelium and reduction of villus height, associated with marked inflammatory cell infiltration over the lamina propria. These results suggest that endogenous NO may play a role in the protecting intestinal integrity after IRI.

Modulations of Spinal Serotonin Activity Affect the Development of Morphine Tolerance

To test whether modulations of spinal serotonin (5-HT) levels would affect the development of morphine tolerance, we treated rats with either intrathecal 5-HT or 5,7-dihydroxytryptamine (5,7-DHT; a 5-HT neurotoxin) in addition to systemic infusion with morphine (2 mg x kg(-1) x h(-1)). Continuous infusion of 5-HT (10 microg x 6 microL(-1) x h(-1)) into the lumbar subarachnoid space of rats for 9 h accelerated the development of morphine tolerance. The area under the curve for the tail-flick latency test was 454.1 +/- 35.1 in the Sham Control group vs 327.6 +/- 41.0 in the 5-HT-Infused group. mu-opioid receptor binding in the lumbar spinal cord showed a decrease in the Bmax (maximal binding -46.5%), but not the binding affinity (Kd), in 5-HT-infused rats. However, intrathecal injection of 5,7-DHT (50 microg), which resulted in a 48% reduction in 5-HT and 51% reduction in 5-hydroxyindoleacetic acid concentrations, led to an attenuation of morphine tolerance (the area under the curve was 613.0 +/- 24.7 in the 5,7-DHT-Lesioned group). The binding study indicated that the affinity of lumbar micro-opioid receptors decreased 196% in 5-HT-depleted rats, whereas there was no effect on apparent binding. The infusion of 5-HT (10 microg x 6 microL(-1) x h(-1)) was not analgesic and the 5,7-DHT-induced lesion did not affect acute morphine-induced analgesia. We conclude that activity of spinal 5-HT-containing neurons plays a crucial role during the development of morphine tolerance.

Therapeutic effect of sheng-ji-san on pressure ulcers

In the present study, the effectiveness of sheng-ji-san (SJS) in promoting the healing of pressure ulcers was evaluated. Thirty-two patients with pressure ulcers were divided into two groups. The treated group received routine medical care combined with SJS treatment and the control group received only routine medical care. After three weeks, the treated group showed a significant reduction in both surface area and depth grade, while the control group showed no significant change. The reduction ratio of the surface area of the ulcer and the effectiveness ratio for the treated group were significantly higher than for the control group. Multiple Linear Regression Analysis revealed that only the SJS treatment was significantly associated with the reduction of surface area and that the use of SJS could independently explain the observed high effectiveness ratio and a relatively high Odds Ratio of 9.539. These results indicate that SJS is effective in promoting the healing of pressure ulcers and should be considered as an adjuvant to routine therapy.

Periaortic contrast medium extravasation on chest CT in traumatic aortic injury: a sign for immediate thoracotomy

Traumatic aortic injury (TAI) after blunt chest trauma is potentially a lethal condition. The injury must be diagnosed promptly and accurately. Evaluation for traumatic aortic injury begins with an assessment of mechanism of injury, a physical examination and chest radiography. In recent years, chest computed tomography (CT) has been advocated as a better screening tool to detect TAI but there is still controversial over the confirmatory diagnostic value of CT. For hemodynamically unstable patients in whom chest CT had shown direct sign of aortic injury and with periaortic contrast medium extravasation, we advocate that these patients should be operated on immediately without aortogram to avoid unnecessary delay. Herein, we describe a case of TAI with direct signs and periaortic contrast extravasation and discuss if chest CT can substitute an aortogram as a diagnostic tool when direct signs of TAI are revealed.

Tirofiban Administration Attenuates Platelet and Platelet-Neutrophil Conjugation but not Neutrophil Degranulation during In Vitro VAD Circulation

Ventricular Assist Devices (VADs) have been used as bridges to heart transplantation. However, VAD circulation is complicated by the incidence of thromboembolism, prolonged bleeding, and activation of the inflammatory cascade. We hypothesize that platelet and neutrophil activation are interrelated and linked to the activation of the glycoprotein (GP) IIb/IIIa platelet receptor. The purpose of this study is to evaluate the effects of Tirofiban, a platelet GP IIb/IIIa receptor inhibitor, on platelet and neutrophil activation during simulated VAD circulation. Two groups of five in vitro VAD circuits were simulated with and without Tirofiban using 450 cc of human blood. Blood samples were drawn at specific time intervals up to 72 hours, measuring leukotriene C4 (LTC4), platelet factor four (PF4), and neutrophil elastase. Tirofiban decreased serum levels of PF4 and LTC4 during VAD circulation. Neutrophil elastase secretion was not affected by Tirofiban administration. Preconditioning of VAD circulation with Tirofiban attenuated platelet activation as demonstrated by a decrease in serum PF4 levels. Tirofiban administration ameliorates the inflammatory response by altering platelet-neutrophil interaction as demonstrated by a decrease in LTC4 production. Continued elastase secretion indicates that the inflammatory response is not completely inhibited by Tirofiban administration. These results suggest that neutrophils may be activated by alternative mechanisms. Early complement activation has been demonstrated during in vivo and in vitro VAD circulation and may play a role in mediating inflammatory and thromboembolic reactions during VAD use.

Radiosurgical management of benign cavernous sinus tumors: dose profiles and acute complications

OBJECTIVE

Radiosurgery has emerged as an alternative treatment modality for cranial base tumors in patients deemed not suited for primary surgical extirpation, patients with recurrent or residual tumor after open surgery, or patients who refuse surgical treatment. We review our short-term experience with radiosurgical management of cavernous sinus region tumors with the Leksell gamma knife.

METHODS

From August 1994 to February 1999, 69 patients with cavernous sinus lesions were treated in 72 separate treatment sessions. The tumor type distribution was 29 pituitary adenomas, 35 meningiomas, 4 schwannomas, and 1 paraganglioma. The median follow-up was 122 weeks. Lesions were stratified according to a five-level surgical grade. The grade distribution of the tumors was as follows: Grade I, 13; Grade II, 21; Grade III, 19; Grade IV, 12; Grade V, 4. Median tumor volume was 4.7 cm3. The median radiation dose was 15 Gy to the 50% isodose line. Median maximal radiation dose was 30 Gy.

RESULTS

Analysis of tumor characteristics and radiation dose to optic nerve and pontine structures revealed a significant correlation between distance and dose. Much lower correlation coefficients were found between tumor volume and dose. One lesion in this series had evidence of transient progression and later regression on follow-up radiographic studies. No other lesions in this series were demonstrated to have exhibited progression. Complications after radiosurgical treatment were uncommon. Two patients had cranial nerve deficits after treatment. One patient with a surgical Grade III pituitary adenoma had VIth cranial nerve palsy 25 months after radiosurgical treatment that spontaneously resolved 10 months later. A patient with a bilateral pituitary adenoma experienced bilateral VIth cranial nerve palsy 3 months after treatment that had not resolved at 35 months after treatment. Six patients with preoperative cranial nerve deficits experienced resolution or improvement of their deficits after treatment. One patient with a prolactin-secreting adenoma experienced normalization of endocrine function with return of menses.

CONCLUSION

Radiosurgical treatment represents an important advance in the management of cavernous sinus tumors, with low risk of neurological deficit in comparison with open surgical treatment, even in patients with high surgical grades.

Surgical treatment for concomitant fractures of the femoral neck and diaphysis: a treatment protocol

Concomitant ipsilateral femoral shaft and neck fractures are difficult to treat. The standard protocol in our hospital is plates for diaphyseal fractures and lag screws or dynamic hip screws (DHS) fixations for the femoral neck fractures. We treated 21 patients with these complex fractures between 1988 and 1998 with this protocol. All patients were injured from high-energy trauma. There were 15 males and 6 females with an average age of 44 years. The average follow-up period is 50 months. All except one patient united well. During the follow-up period, neither non-union of the femoral neck fracture nor osteonecrosis of the femoral head was noted. There was also no malunion. There were twenty good results and one poor functional result. We conclude that plate on the shaft and sliding hip screws or separate screws in the hip are a reliable method for concomitant ipsilateral femoral neck and shaft fractures.