Measurement of inclusive antiprotons from Au+Au collisions at square root of s(NN) = 130 GeV

We report the first measurement of inclusive antiproton production at midrapidity in Au+Au collisions at square root of s(NN) = 130 GeV by the STAR experiment at RHIC. The antiproton transverse mass distributions in the measured transverse momentum range of 0.25<p( perpendicular)<0.95 GeV/c are found to fall less steeply for more central collisions. The extrapolated antiproton rapidity density is found to scale approximately with the negative hadron multiplicity density.

d Macro and (3)He macro production in square root of s(NN) = 130 GeV Au+Au collisions

The first measurements of light antinucleus production in Au+Au collisions at the Relativistic Heavy-Ion Collider are reported. The observed production rates for d macro and (3)He macro are much larger than in lower energy nucleus-nucleus collisions. A coalescence model analysis of the yields indicates that there is little or no increase in the antinucleon freeze-out volume compared to collisions at CERN SPS energy. These analyses also indicate that the (3)He macro freeze-out volume is smaller than the d macro freeze-out volume.

Prediction of hyperbilirubinemia in near-term and term infants

OBJECTIVE

The purpose of this study was to determine whether end-tidal carbon monoxide (CO) corrected for ambient CO (ETCOc), as a single measurement or in combination with serum total bilirubin (STB) measurements, can predict the development of hyperbilirubinemia during the first 7 days of life.

METHODS

From nine multinational clinical sites, 1370 neonates completed this cohort study from February 20, 1998 through February 22, 1999. Measurements of both ETCOc and STB were performed at 30+/-6 hours of life; STB also was measured at 96+/-12 hours and subsequently following a flow diagram based on a table of hours of age-specific STB. An infant was defined as hyperbilirubinemic if the hours of age-specific STB was greater than or equal to the 95th percentile as defined by the table at any time during the study.

RESULTS

A total of 120 (8.8%) of the enrolled infants became hyperbilirubinemic. Mean STB in breast-fed infants was 8.92+/-4.37 mg/dl at 96 hours versus 7.63+/-3.58 mg/dl in those fed formula only. The mean ETCOc at 30+/-6 hours for the total population was 1.48+/-0.49 ppm, whereas those of nonhyperbilirubinemic and hyperbilirubinemic infants were 1.45+/-0.47 and 1.81+/-0.59 ppm, respectively. Seventy-six percent (92 of 120) of hyperbilirubinemic infants had ETCOc greater than the population mean. An ETCOc greater than the population mean at 30+/-6 hours yielded a 13.0% positive predictive value (PPV) and a 95.8% negative predictive value (NPV) for STB > or =95th percentile. When infants with STB > or =95th percentile at <36 hours of age were excluded, the STB at 30+/-6 hours yielded a 16.7% PPV and a 98.1% NPV for STB >75th percentile. The combination of these two measurements at 30+/-6 hours (either ETCOc more than the population mean or STB >75th percentile) had a 6.4% PPV with a 99.0% NPV.

CONCLUSIONS

This prospective cohort study supports previous observations that measuring STB before discharge may provide some assistance in predicting an infant's risk for developing hyperbilirubinemia. The addition of an ETCOc measurement provides insight into the processes that contribute to the condition but does not materially improve the predictive ability of an hours of age-specific STB in this study population. The combination of STB and ETCOc as early as 30+/-6 hours may identify infants with increased bilirubin production (eg, hemolysis) or decreased elimination (conjugation defects) as well as infants who require early follow-up after discharge for jaundice or other clinical problems such as late anemia. Depending on the incidence of hyperbilirubinemia within an institution, the criteria for decision making should vary according to its unique population.

Genetic interactions in the pathogenesis of neonatal hyperbilirubinemia: Gilbert's Syndrome and glucose-6-phosphate dehydrogenase deficiency

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is a common condition with a worldwide distribution that has the potential for causing severe hyperbilirubinemia with bilirubin encephalopathy. Hemolysis resulting from identifiable triggers may be the cause of the jaundice in some cases, but in many, jaundice continues to occur despite avoidance of contact with known hemolytic triggers. In some G-6-PD-deficient population groups, carboxyhemoglobin studies have indicated exaggerated hemolysis; but in others, increased hemolysis has not correlated with serum total bilirubin values. As hyperbilirubinemia results from an imbalance between bilirubin production and bilirubin elimination, diminished bilirubin conjugation was suspected to contribute to the pathogenesis of hyperbilirubinemia. Serum-conjugated bilirubin fractions, reflecting intrahepatocytic bilirubin conjugation, were low in G-6-PD-deficient neonates who developed hyperbilirubinemia. This conjugated bilirubin profile was similar to that seen in adults with Gilbert's Syndrome, a condition associated with promoter polymorphism for the gene encoding the bilirubin-conjugating enzyme, UGT glucuronosyltransferase 1A1 (UGT). Whereas G-6-PD deficiency or Gilbert's Syndrome, alone, did not predispose to hyperbilirubinemia, G-6-PD-deficient neonates who also were heterozygotes or homozygotes for the variant UGT gene promoter did have significantly increased incidences of hyperbilirubinemia. Additional conditions which predispose to neonatal jaundice in the presence of Gilbert's Syndrome, include Coombs' negative ABO blood group heterospecificity, hereditary spherocytosis, and prolonged breastfeeding.Gilbert's Syndrome and G-6-PD deficiency are both common, inherited conditions. Individually, and in the absence of additional genetic or environmental factors, both are benign, and should result in minimal health disturbance or interference with the quality of life of affected individuals. However, in combination, or following exposure to environmental or other genetic factors, these benign conditions may have severe manifestations, with potentially dangerous and possibly life-threatening consequences. This review highlights the major clinical features of both Gilbert's Syndrome and G-6-PD deficiency, and surveys a series of studies related to neonatal jaundice in G-6-PD-deficient neonates culminating in the documentation of an interaction between the two conditions that is crucial to the pathogenesis of hyperbilirubinemia.

Reconstruction with rectus abdominis myocutaneous free flap after orbital exenteration in children

OBJECTIVE

To present a 1-stage technique for orbital reconstruction after exenteration with the use of myocutaneous rectus abdominis free flap in children.

SURGICAL TECHNIQUE

After orbital exenteration, a myocutaneous rectus abdominis free flap with long vascular pedicle is harvested from the abdomen. The flap is transferred to the orbit and the vascular pedicle is passed through an opening made in the lateral orbital wall, where it is anastomosed to superficial temporal vessels. The skin of the flap is trimmed to correspond to the eyelid defect and the incisions are closed.

METHODS

After informed consent was obtained, 2 children, 3 and 8 years old, underwent orbital reconstruction with a rectus abdominis free flap after exenteration for orbital rhabdomyosarcoma and orbital osteosarcoma in the setting of retinoblastoma.

RESULTS

This technique allowed easy postoperative wound care. Viability of the flap was excellent. The technique provided sufficient volume to fill the orbit, with improved aesthetic results and minimal donor site deformity.

CONCLUSIONS

The postoperative care and aesthetic outcome in patients with rectus abdominis free flap after exenteration are much improved over those provided with traditional surgical techniques. This primary reconstruction is recommended for any patient requiring orbital exenteration, but particularly for pediatric patients who tolerate debridement of traditional exenteration sites poorly.

Differing pathogenesis of perinatal bilirubinemia in glucose-6-phosphate dehydrogenase-deficient versus-normal neonates

The objective was to compare the contribution to perinatal bilirubinemia of hemolysis and UDP-glucuronosyltransferase (UGT) gene promoter polymorphism, seen in Gilbert's syndrome, between glucose-6-phosphate dehydrogenase (G-6-PD)-deficient and -normal neonates. Serum total bilirubin (STB) values from 52 G-6-PD-deficient and 166 G-6-PD-normal term, male neonates, sampled within 3 h of delivery (first sample) and on d 3 (second sample), were analyzed in relation to blood carboxyhemoglobin corrected for inspired CO (COHbc), an accurate index of hemolysis, and UGT promoter genotype. COHbc values (% total Hb) were greater in G-6-PD-deficient neonates than controls: first sample 1.00 +/- 0.25% versus 0.84 +/- 0.24%, p < 0.0001; second sample 0.83 +/- 0.20% versus 0.76 +/- 0.19%, p = 0.002. First sample COHbc and STB values did not correlate in either the G-6-PD-deficient or control groups, whereas second sample COHbc values correlated significantly with corresponding STB values in the control population only (r = 0.28, p = 0.0007). At second sampling, there was a higher allele frequency of the variant UGT promoter among those with STB values > or =75th percentile than those <75th among the G-6-PD-deficient neonates (0.60 versus 0.33, respectively, p = 0.025), but not controls (0.31 versus 0.40, respectively, p = 0.24). Among those infants with at least one variant UGT promoter allele, STB values were higher in the G-6-PD-deficient neonates than controls at second sampling only (181 +/- 56 microM versus 149 +/- 46 microM, respectively, p = 0.03). Both within and between the G-6-PD-deficient and control groups, our data demonstrate changing and differing contributions of hemolysis and UGT promoter polymorphism to bilirubinemia during the first 3 d of life.

Onset of jaundice in glucose-6-phosphate dehydrogenase-deficient neonates

OBJECTIVE

We asked whether neonatal jaundice associated with glucose-6-phosphate dehydrogenase (G-6-PD) deficiency commences either in utero or in the immediate postnatal period and whether this perinatal bilirubinemia is the precursor of the subsequent neonatal jaundice and hyperbilirubinemia.

METHODS

Mandatory serum total bilirubin (STB) determinations were performed within 3 hours of birth, to reflect the in utero state (first STB), and on the third day of life (second STB), with additional determinations as clinically necessary, on healthy, term male neonates at high risk for G-6-PD deficiency. G-6-PD Mediterranean mutation was determined by molecular means. G-6-PD-deficient neonates were compared with control participants. The relationship of first STB values to second STB and subsequent hyperbilirubinemia (defined as STB >/=256 micromol/L [15.0 mg/dL]) was determined.

RESULTS

Both first and second STB values were significantly higher in the G-6-PD-deficient neonates (n = 52) than in control participants (n = 166; 50 +/- 12 micromol/L vs 44 +/- 10 micromol/L [2.9 +/- 0.7 mg/dL vs 2.6 +/- 0.6 mg/dL] and 174 +/- 52 micromol/L vs 152 +/- 52 micromol/L [10.2 +/- 3.1 mg/dL vs 8.9 +/- 3.0 mg/dL] for the first and second STB values, respectively). The rate of rise between these 2 points was greater in the G-6-PD-deficient neonates (2.6 +/- 0.9 micromol/L/h vs 2.2 +/- 0.9 micromol/L/h [0.15 +/- 0.05 mg/dL/h vs 0.13 +/- 0.05 mg/dL/h). Sixteen (30.8%) of the G-6-PD-deficient neonates developed hyperbilirubinemia compared with 10 (6%) of control participants (relative risk: 5.11; 95% confidence interval: 2.47-10.56). In both G-6-PD-deficient and normal populations, first STB values correlated significantly with both second STB values and with those who subsequently developed hyperbilirubinemia. Significantly more G-6-PD-deficient neonates with a first STB value greater than or equal to the mean developed hyperbilirubinemia compared with those with first STB less than the mean: 13 of 28 neonates versus 3 of 24 (relative risk: 3.7; 95% confidence interval: 1.20-11.51). This difference did not reach statistical significance in the control group.

CONCLUSIONS

Higher first STB values, an increased risk of hyperbilirubinemia in G-6-PD-deficient neonates with first STB value greater than or equal to the mean, and significant correlation between first STB values and second STB values and hyperbilirubinemia suggest that jaundice in G-6-PD-deficient neonates commences in the immediate perinatal period, most likely in utero.

Multiplicity distribution and spectra of negatively charged hadrons in Au+Au collisions at square root of (sNN) = 130 GeV

The minimum-bias multiplicity distribution and the transverse momentum and pseudorapidity distributions for central collisions have been measured for negative hadrons ( h(-)) in Au+Au interactions at square root of ([s(NN)]) = 130 GeV. The multiplicity density at midrapidity for the 5% most central interactions is dN(h(-))/d(eta)/(eta = 0) = 280+/-1(stat)+/-20(syst), an increase per participant of 38% relative to pp collisions at the same energy. The mean transverse momentum is 0.508+/-0.012 GeV/c and is larger than in central Pb+Pb collisions at lower energies. The scaling of the h(-) yield per participant is a strong function of p( perpendicular). The pseudorapidity distribution is almost constant within /eta/<1.

Model-independent source imaging using two-pion correlations in (2 to 8)a GeV Au+Au collisions

We report a particle source imaging analysis based on two-pion correlations in high multiplicity Au+Au collisions at beam energies between 2A and 8A GeV. We apply the imaging technique introduced by Brown and Danielewicz, which allows a model-independent extraction of source functions with useful accuracy out to relative pion separations of about 20 fm. The extracted source functions have Gaussian shapes. Values of source functions at zero separation are almost constant across the energy range under study. Imaging results are found to be consistent with conventional source parameters obtained from a multidimensional Hanburg-Brown-Twiss analysis.

Angiotensin II administration to atherosclerotic mice increases macrophage uptake of oxidized ldl: a possible role for interleukin-6

The goal of the present study was to elucidate mechanisms for angiotensin II (Ang II) induction of oxidized low density lipoprotein (Ox-LDL) uptake by macrophages, the hallmark of early atherosclerosis. Compared with placebo treatment, Ang II injections (0.1 mL, 10(-7) mol/L per day) for 2 weeks to apolipoprotein E-deficient mice significantly increased Ox-LDL degradation, CD36 mRNA expression, and CD36 protein expression by their peritoneal macrophages (MPMs). These effects were abolished by treatment with losartan (5 to 50 mg/kg per day) before Ang II administration. Because no such effect was obtained in vitro, the ex vivo effect of Ang II on macrophage uptake of Ox-LDL could be mediated by a factor that is not expressed at a significant level in vitro. Because Ang II stimulates cellular production of interleukin-6 (IL-6), we analyzed the possible role of IL-6 as a mediator of Ang II-mediated cellular uptake of Ox-LDL by using several approaches. First, incubations of IL-6 with MPM or IL-6 administration in mice increased macrophage Ox-LDL degradation and CD36 mRNA expression. Second, injection of IL-6 receptor antibodies in mice during Ang II treatment reduced macrophage Ox-LDL uptake and CD36 expression compared treatment with Ang II alone. Finally, Ang II treatment of IL-6-deficient mice did not affect their MPM Ox-LDL uptake and CD36 protein levels. Thus, we conclude that a novel mechanism for Ang II atherogenicity, related to macrophage cholesterol accumulation and foam cell formation, may involve its stimulatory effect on macrophage uptake of Ox-LDL, a process mediated byIL-6.

Pion Interferometry of square root of (s(NN)) =130 GeV Au + Au collisions at RHIC

Two-pion correlation functions in Au+Au collisions at square root of [s(NN)] = 130 GeV have been measured by the STAR (solenoidal tracker at RHIC) detector. The source size extracted by fitting the correlations grows with event multiplicity and decreases with transverse momentum. Anomalously large sizes or emission durations, which have been suggested as signals of quark-gluon plasma formation and rehadronization, are not observed. The Hanbury Brown-Twiss parameters display a weak energy dependence over a broad range in square root of [s(NN)].

Pomegranate juice supplementation to atherosclerotic mice reduces macrophage lipid peroxidation, cellular cholesterol accumulation and development of atherosclerosis

Inhibition of lipid peroxidation contributes to the attenuation of macrophage cholesterol accumulation, foam-cell formation and atherosclerosis. Evidence suggests that nutritional antioxidants such as pomegranate juice (PJ) can contribute to the reduction of oxidative stress and atherogenesis. The goals of the present study were to determine whether such beneficial effects of PJ exist when supplemented to apolipoprotein E-deficient (E(0)) mice with advanced atherosclerosis and to analyze the antiatherosclerotic activity of a tannin-fraction isolated from PJ. Mice (4-mo-old) were supplemented with PJ in their drinking water for 2 mo and compared with age-matched placebo-treated mice, as well as to young (4-mo-old) control mice, for their mouse peritoneal macrophage (MPM) oxidative state, cholesterol flux and mice atherosclerotic lesion size. PJ supplementation reduced each of the proatherogenic variables determined in the present study compared with age-matched placebo-treated mice. It significantly induced serum paraoxonase activity and reduced MPM lipid peroxide content compared with placebo-treated mice and control mice. PJ administration to E(0) mice significantly reduced the oxidized (Ox)-LDL MPM uptake by 31% and MPM cholesterol esterification and increased macrophage cholesterol efflux by 39% compared with age-matched, placebo-treated mice. PJ consumption reduced macrophage Ox-LDL uptake and cholesterol esterification to levels lower than those in 4-mo-old, unsupplemented controls. PJ supplementation to E(0) mice with advanced atherosclerosis reduced the lesion size by 17% compared with placebo-treated mice. In a separate study, supplementation of young (2-mo-old) E(0) mice for 2 mo with a tannin fraction isolated from PJ reduced their atherosclerotic lesion size, paralleled by reduced plasma lipid peroxidation and decreased Ox-LDL MPM uptake. PJ supplementation to mice with advanced atherosclerosis reduced their macrophage oxidative stress, their macrophage cholesterol flux and even attenuated the development of atherosclerosis. Moreover, a tannin-fraction isolated from PJ had a significant antiatherosclerotic activity.

Prediction of hyperbilirubinemia in near-term and term infants

OBJECTIVE

The purpose of this study was to determine whether end-tidal carbon monoxide (CO) corrected for ambient CO (ETCOc), as a single measurement or in combination with serum total bilirubin (STB) measurements, can predict the development of hyperbilirubinemia during the first 7 days of life.

METHODS

From 9 multinational clinical sites, 1370 neonates completed this cohort study from February 20, 1998, through February 22, 1999. Measurements of both ETCOc and STB were performed at 30 +/- 6 hours of life; STB also was measured at 96 +/- 12 hours and subsequently following a flow diagram based on a table of hours of age-specific STB. An infant was defined as hyperbilirubinemic if the hours of age-specific STB was greater than or equal to the 95th percentile as defined by the table at any time during the study.

RESULTS

A total of 120 (8.8%) of the enrolled infants became hyperbilirubinemic. Mean STB in breastfed infants was 8.92 +/- 4.37 mg/dL at 96 hours versus 7.63 +/- 3.58 mg/dL in those fed formula only. The mean ETCOc at 30 +/- 6 hours for the total population was 1.48 +/- 0.49 ppm, whereas those of nonhyperbilirubinemic and hyperbilirubinemic infants were 1.45 +/- 0.47 ppm and 1.81 +/- 0.59 ppm, respectively. Seventy-six percent (92 of 120) of hyperbilirubinemic infants had ETCOc greater than the population mean. An ETCOc greater than the population mean at 30 +/- 6 hours yielded a 13.0% positive predictive value (PPV) and a 95.8% negative predictive value (NPV) for STB >/=95th percentile. When infants with STB >95th percentile at <36 hours of age were excluded, the STB at 30 +/- 6 hours yielded a 16.7% PPV and a 98.1% NPV for STB >75th percentile. The combination of these 2 measurements at 30 +/- 6 hours (either ETCOc more than the population mean or STB >75th percentile) had a 6.4% PPV with a 99.0% NPV. Conclusions. This prospective cohort study supports previous observations that measuring STB before discharge may provide some assistance in predicting an infant's risk for developing hyperbilirubinemia. The addition of an ETCOc measurement provides insight into the processes that contribute to the condition but does not materially improve the predictive ability of an hours of age-specific STB in this study population. The combination of STB and ETCOc as early as 30 +/- 6 hours may identify infants with increased bilirubin production (eg, hemolysis) or decreased elimination (conjugation defects) as well as infants who require early follow-up after discharge for jaundice or other clinical problems such as late anemia. Depending on the incidence of hyperbilirubinemia within an institution, the criteria for decision making should vary according to its unique population.

Acute hemolysis and severe neonatal hyperbilirubinemia in glucose-6-phosphate dehydrogenase-deficient heterozygotes

Two premature female infants had severe hyperbilirubinemia caused by hemolysis. Both neonates were heterozygotes for the glucose-6-phosphate dehydrogenase Mediterranean mutation as determined by DNA analysis. Glucose-6-phosphate dehydrogenase-deficient heterozygotes may be susceptible to the complications of this enzyme deficiency.

Spontaneous cerebrospinal fluid rhinorrhea associated with chronic renal failure--case report

A 39-year-old woman was admitted with complaints of headache and nasal discharge on the left for 3 months which was later on proved to be cerebrospinal fluid (CSF). Neurological examination found no abnormalities except bilateral papilledema. Neuroimaging demonstrated enlargement of the lamina cribrosa foramina through which the olfactory nerves pass, as well as empty sella and cerebral cortical atrophy. Bone mineral densitometry showed osteopenia. CSF Ca++ and blood parathyroid hormone levels were elevated. CSF pressure was 280 mmH2O. Bilateral frontal craniotomy was performed to expose the anterior fossa. Foraminal enlargement at the lamina cribrosa was confirmed, and islands of extra-osseous calcifications on the arachnoid membrane were identified. The base of the anterior fossa was repaired intradurally with fascial graft and fibrin glue on both sides. No CSF leakage was noted at 1-year follow up. Spontaneous CSF leakage probably resulted from enlargement of the foramina at the lamina cribrosa due to Ca++ mobilization from bones and pseudotumor cerebri not to the extent of hydrocephalus caused by poor CSF absorption at the arachnoid granulations obliterated by extra-osseous calcareous accumulation.

Midrapidity antiproton-to-proton ratio from Au+Au collisions at sqrt [s(NN)]=130 GeV

We report results on the ratio of midrapidity antiproton-to-proton yields in Au+Au collisions at sqrt[s(NN)] = 130 GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of /y/<0.5 and 0.4<p(t)<1.0 GeV/c, the ratio is essentially independent of either transverse momentum or rapidity, with an average of 0.65+/-0.01((stat))+/-0.07((syst)) for minimum bias collisions. Within errors, no strong centrality dependence is observed. The results indicate that at this RHIC energy, although the p-p pair production becomes important at midrapidity, a significant excess of baryons over antibaryons is still present.

Moderate involvement in sports is related to lower depression levels among adolescents

Sports involvement has been found to be related to social and psychological well-being in Icelandic adolescents. The present study investigated whether similar relationships exist for American adolescents. A group of 89 high school seniors completed a questionnaire that gathered data on sports involvement, depression, intimacy with parents and friends, and grade point average. It was found that the moderate sports involvement group (3 to 6 hours per week) had lower depression scores than did the low sports involvement group (2 hours or less per week). The findings are discussed.

Cardiac hydatid cysts with intracavitary expansion

BACKGROUND

Hydatid cyst disease is a significant health problem for undeveloped and developing countries. Although cardiac involvement is rare, early diagnosis and treatment of this situation is important.

METHODS

To investigate the long-term outcome of patients who underwent operation for cardiac hydatid cysts with intracavitary expansion, we reviewed 8 patients who had cardiac hydatidosis and who underwent operation in our institution between January 1988 and November 1999. All patients presented with intracavitary protrusion of the cysts. Seven patients were women. The mean age was 33 +/- 14.3 years with a range of 17 to 55 years. The cysts were located on the right ventricular outflow tract (2 patients), right midventricular part of the muscular septum, left atrial free wall and apical portions of the right (2), or left (2 patients) ventricle. Standard cardiopulmonary bypass and crystalloid antegrade cardioplegia with aortic cross-clamping were used in all patients. In one, with right ventricular hydatid cyst, we used cardiopulmonary bypass with femoral cannulation and total circulatory arrest at less than 18 degrees C systemic hypothermia. This patient, who was arrested because of pulmonary emboli could not be weaned from cardiopulmonary bypass and died.

RESULTS

The cystic cavity was cleaned and closed with multiple pursestring sutures in 4 patients. In 2, cardiac and cystic cavities were united by partially resecting part of the cyst facing the cavity. In another patient, a left ventricular patch plasty was performed after removal of the cystic material in the left ventricle. Mebendazole was used postoperatively in all patients. Except for 1 patient who died, all were discharged without postoperative complications. The mean follow-up was 7.5 +/- 5 years. There was no late cardiac mortality or recurrence.

CONCLUSIONS

Cardiac hydatid cysts with intracavitary expansion should be treated surgically without delay. Gentle handling of the heart during cardiopulmonary bypass minimizes operative risk. All patients should be investigated for systemic cysts.

CYP3A inductive potential of the rifamycins, rifabutin and rifampin, in the rabbit

Rifabutin is effective in the treatment and prevention of Mycobacterium avium infection in people with HIV infection. Rifabutin is structurally related to another rifamycin, rifampin, a well-known inducer of the human P-450 isoform 3A. The rabbit isoform CYP3A6 and the human isoform CYP3A4 have similar P-450 predominance and substrate specificity and are both induced by rifampin. Our goal was to predict the CYP3A induction capacity of rifabutin and to determine if ex vivo CYP3A induction potential of rifamycins is predictive of that obtained in vivo. We determined the in vivo and ex vivo CYP3A6 induction by 4 days of treatment with rifabutin (100 mg/kg), rifampin (100 mg/kg), or vehicle (DMSO) in the rabbit. The ex vivo measures were CYP3A6 activity (N-demethylation of erythromycin and hydroxylation of triazolam) and CYP3A content in rabbit hepatic microsomes preparations. The in vivo measures were oral clearance of triazolam and its formation clearance to its hydroxylated metabolites, alpha-hydroxytriazolam and 4-hydroxytriazolam. Rifampin increased CYP3A6 activity by 2- to 3-fold in hepatic microsomes compared to vehicle. Rifabutin increased CYP3A content 1.7-fold, but did not significantly increase microsomal CYP3A6 activity. Oral triazolam clearance and formation clearances to the two hydroxylated metabolites were 2- to 3-fold greater in rabbits treated with rifampin. These clearances were unaffected by rifabutin administration. Ex vivo enzyme activities correlated with in vivo changes in clearance of triazolam and the formation clearance to its hydroxylated metabolites. Rifabutin is a weaker inducer of CYP3A6 than rifampin. These data suggest that ex vivo enzyme activity is a viable approach to predict in vivo inductive potential of CYP3A inducers.

Tentorial vascularization in solid hemangioblastoma--case report

A 40-year-old female was admitted to the hospital with complaints of headache worsening gradually over a 1-month duration. Her past history included surgery to treat a left cerebellar cystic lesion 3 years before, and an untreated small solid right supracerebellar lesion of 1 cm diameter. On admission, magnetic resonance imaging showed that the right cerebellar lesion had grown to approximately 4 cm diameter abutting the tentorium and causing obstructive hydrocephalus. She also had two more small lesions, a right supratentorial solid lesion with cystic component near the splenium and an intramedullary cystic lesion at the C-2 level. Right suboccipital craniectomy was done. The vascular attachments between the superior aspect of the tumor and the tentorium were coagulated and the tumor was totally removed. C1-2 laminectomy was also performed to drain the intramedullary cyst. The patient deteriorated and lost consciousness with respiratory arrest 6 hours postoperatively and was reoperated for intracerebellar hematoma due to oozing from the tentorial vessels. Histological investigation revealed hemangioblastoma. Dural tentorial vascular attachments in solid hemangioblastomas located subjacent to the tentorium may cause early postoperative complications of hematoma at the site of vascular attachment following the resection. Computed tomography study in the early postoperative period is helpful to identify this problem.

Macrophage-derived chemokine gene expression in human and macaque cells: mRNA quantification using NASBA technology

Macrophage-derived chemokine (MDC) is a CC-chemokine that inhibits infection by both macrophage- and T cell-tropic strains of HIV-1. This suppressor activity has led to great interest in fully characterizing the role of MDC in the pathogenesis of HIV-1 infection. Methods for the quantitation of constitutive levels of MDC protein in vivo are lacking. In this report, we describe the development and performance of a NASBA-based assay for the quantification of MDC mRNA expression in human and macaque cells. Although the constitutive in vivo levels of MDC mRNA in macaque and human T lymphocytes were low, in vitro activation of these cells greatly increased MDC transcription. Levels in the human and macaque cells were comparable under all conditions tested. Positive correlations between MDC transcription and protein expression were observed. The results indicate that this assay is extremely sensitive and reproducible over a five log dynamic range, and effectively quantifies MDC mRNA in resting and activated T cells. This assay may therefore permit characterization of the role of MDC in HIV-1/SIV pathogenesis, and in vaccine-induced immune responses.