Biomedical subjects

A Shapiro

Publications and source records attributed to A Shapiro.

At least 37 records · Page 2Linked to original sources

PubMed2001

Search for the decay upsilon(1S) --> gammaeta(').

We report on a search for the radiative decay Upsilon(1S)-->gammaeta(') in 61.3 pb(-1) of data taken with the CLEO II detector at the Cornell Electron Storage Ring. Three decay chains were investigated, all involving eta(')-->pi(+)pi(-)eta, followed by eta-->gammagamma, eta-->pi(0)pi(0)pi(0), or eta-->pi(+)pi(-)pi(0). We find no candidate events in any of the three cases and set a combined upper limit of 1.6x10(-5) at 90% C.L., significantly smaller than the previous limit. We compare our result to other radiative Upsilon decays, to radiative J/psi decays, and to theoretical predictions.

Journal Article↗

PubMed2001

Experimental investigation of the two-photon widths of the chi(c0) and the chi(c2) mesons.

Using 12.7 fb(-1) of data collected with the CLEO detector at CESR, we observed two-photon production of the cc states chi(c0) and chi(c2) in their decay to pi(+)pi(-)pi(+)pi(-). We measured gamma(gammagamma)(chi(c))xB(chi(c)-->pi(+)pi(-)pi(+)pi(-)) to be 75+/-13(stat)+/-8(syst) eV for the chi(c0) and 6.4+/-1.8(stat)+/-0.8(syst) eV for the chi(c2), implying gamma(gammagamma)(chi(c0)) = 3.76+/-0.65(stat)+/-0.41(syst)+/-1.69(br) keV and gamma(gammagamma)(chi(c2)) = 0.53+/-0.15(stat)+/-0.06(syst)+/-0.22(br) keV. Also, cancellation of dominant experimental and theoretical uncertainties permits a precise comparison of gamma(gammagamma)(chi(c0))/gamma(gammagamma)(chi(c2)), evaluated to be 7.4+/-2.4(stat)+/-0.5(syst)+/-0.9(br), with QCD-based predictions.

Journal Article↗

PubMed2001

Bounds on the CP asymmetry in b --> sgamma decays.

We have measured the CP asymmetry A(CP) identical with[gamma(b-->sgamma)-gammab-->sgamma)]/[gamma(b-->sgamma)+gamma(b-->sgamma)] to be A(CP) = (-0.079+/-0.108+/-0.022) (1.0+/-0.030), implying that, at 90% confidence level, A(CP) lies between -0.27 and +0.10. These limits rule out some extreme non-standard-model predictions, but are consistent with most, as well as with the standard model.

Journal Article↗

PubMed2001

Study of tau decays to six pions and a neutrino.

The tau decays to six-pion final states have been studied with the CLEO detector at the Cornell Electron Storage Ring. The measured branching fractions are B(tau(-)-->2pi(-)pi(+)3pi(0)nu(tau)) = (2.2+/-0.3+/-0.4)x10(-4) and B(tau(-)-->3pi(-)2pi(+)pi(0)nu(tau)) = (1.7+/-0.2+/-0.2)x10(-4). A search for substructure in these decays shows that they are saturated by intermediate states with eta or omega mesons. We present the first observation of the decay tau(-)-->2pi(-)pi(+)omega(nu)tau and the branching fraction is measured to be (1.2+/-0.2+/-0.1)x10(-4). The measured branching fractions are in good agreement with the isospin expectations but somewhat below the conserved-vector-current predictions.

Journal Article↗

PubMed2001

Observation of new states decaying into Lambda+(c)pi(-)pi(+).

Using 13.7 fb(-1) of data recorded by the CLEO detector at the Cornell Electron Storage Ring, we investigate the spectrum of charmed baryons which decay into Lambda+(c)pi(-)pi(+) and are more massive than the Lambda+(c)(2625) baryon. We find evidence for two new states: one is broad and has an invariant mass roughly 480 MeV above that of the Lambda+(c) baryon; the other is narrow with an invariant mass of 596+/-1+/-2 MeV above the Lambda+(c) mass.

Journal Article↗

PubMed2001

Evidence of New States Decaying into Xi(*)(c)pi.

Using 13.7 fb(-1) of data recorded by the CLEO detector at Cornell Electron Storage Ring, we report evidence of two new charmed baryons: one decaying into Xi(0')(c)pi(+) with the subsequent decay Xi(0')(c)-->Xi(0)(c)gamma, and its isospin partner decaying into Xi(+')(c)pi(-) followed by Xi(+')(c)-->Xi(+)(c)gamma. We measure the following mass differences for the two states: M(Xi(0)(c)gammapi(+))-M(Xi(0)(c)) = 318.2+/-1.3+/-2.9 MeV and M(Xi(+)(c)gammapi(-))-M(Xi(+)(c)) = 324.0+/-1.3+/-3.0 MeV. We interpret these new states as the J(P) = 1 / 2(-) Xi(c1) particles, the charmed-strange analogs of the Lambda(+)(c1)(2593).

Journal Article↗

PubMed2001

Observation of the Omega(0)(c) Charmed Baryon at CLEO.

The CLEO experiment at the CESR collider has used 13.7 fb(-1) of data to search for the production of the Omega(0)(c) (css ground state) in e(+)e(-) collisions at square root of (s) approximately 10.6 GeV. The modes used to study the Omega(0)(c) are Omega(-)pi(+), Omega(-)pi(+)pi(0), Xi-K-pi(+)pi(+), Xi0K-pi(+), and Omega(-)pi(+)pi(+)pi(-). We observe a signal of 40.4+/-9.0(stat) events at a mass of 2694.6+/-2.6(stat)+/-1.9(syst) MeV/c(2), for all modes combined.

Journal Article↗

PubMed2001

First observation of the decays B(0) --> D(-)p_p pi+ and B(0) --> D(-)p_n.

We report the first observation of exclusive decays of the type B-->D(*)N_NX, where N is a nucleon. Using a sample of 9.7x10(6)B_B pairs collected with the CLEO detector operating at the Cornell Electron Storage Ring, we measure the branching fractions B(B0-->D(*-)p_p pi(+)) = (6.5(+1.3)(-1.2)+/-1.0)x10(-4) and B(B0-->D(*-)p_n) = (14.5(+3.4)(-3.0)+/-2.7)x10(-4). Antineutrons are identified by their annihilation in the CsI electromagnetic calorimeter.

Journal Article↗

PubMed2001

Measurement of the lambda(+)(c) lifetime.

The Lambda+c lifetime is measured using 9.0 fb(-1) of e+e- annihilation data collected on or just below the Upsilon(4S) resonance with the CLEO II.V detector at CESR. Using an unbinned maximum likelihood fit, the Lambda+c lifetime is measured to be 179.6+/-6.9(stat)+/-4.4(syst) fs. The precision of this colliding beam measurement is comparable to other measurements, which are based on fixed-target experiments, with different systematic uncertainties.

Journal Article↗

PubMed2001

Extracorporeal shock wave lithotripsy is highly effective for ureteral calculi in children.

PURPOSE: Treatment of ureteral calculi in the pediatric population represents a unique challenge. Extracorporeal shock wave lithotripsy (ESWL*) and ureteroscopy have been advocated for the treatment of such stones. We present our experience with ESWL monotherapy for ureteral stones in children in the last decade. MATERIALS AND METHODS: Between 1989 and 1999 we treated 21 boys and 17 girls with a mean age of 8 years (range 8 months to 14 years) with ureteral stones at our institution. Records were reviewed and analyzed for presentation, metabolic and anatomical anomalies, stone size and location, outcome and complications. Average stone size was 9.5 x 6.5 mm. (range 3 to 32). Stones were in the upper ureter in 17 cases, mid ureter in 2 and lower ureter in 19. All patients underwent ESWL with a Dornier HM3 lithotriptor under general anesthesia. Nephrostomies were placed in an anuric infant with bilateral ureteral obstruction and in 2 patients with nonfunctioning kidneys (4 renal units). Ureteral catheters were used in 15 patients for better identification and localization of the stone during ESWL. The catheters were removed immediately postoperatively. RESULTS: Of the patients 31 (81.5%) were free of stones after 1 session of ESWL, 5 (13.1%) after 2 and 1 after 3. One patient underwent ureteroscopy for residual fragments after 2 ESWL sessions. The stone-free rate following 1 ESWL session was 100% for ureteral calculi 10 mm. or smaller regardless of location. Of the 12 patients with stones larger than 10 mm. 8 (67%) were free of stones following 1 ESWL session. The overall success rate of ESWL was 97.3%. No child had postoperative urinary infection or ureteral obstruction. CONCLUSIONS: ESWL is an efficient and safe modality for the treatment of pediatric ureteral stones.

Adolescent↗

PubMed2001

Inhibitor treatment: state of the art.

The treatment of hemophilic patients with inhibitors presents many challenges. Recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Copenhagen, Denmark) is a new therapeutic option for this patient population. Optimization of dosing regimens may be achieved by considering (1) individual pharmacokinetics (especially in the pediatric population); (2) high-dose bolus regimens; (3) continuous infusion (CI) including high-dose CI; (4) early treatment with NovoSeven in the course of a bleeding event; and (5) use of NovoSeven as a prophylactic therapy. The literature involving these issues is reviewed here. Institution of early therapy has been shown to decrease total NovoSeven requirement while increasing efficacy. Pediatric patients may require a higher dose of NovoSeven due to the higher clearance rate and shorter half-life demonstrated by this population. Therefore, the patient's age and/or individual pharmacokinetics and clearance rate should be considered when calculating doses and CI rates. High-dose NovoSeven has been shown to be effective in some patient populations without increased reported adverse events. Despite its short half-life, prophylactic use of NovoSeven has been reported in a small number of patients, with an apparent decrease in bleeding episodes experienced. There has been significant interest in administration of NovoSeven by CI, particularly in patients requiring prolonged treatment, and it has been shown to be successful, although the optimal target factor VII activity has yet to be established and some authors have recommended the use of concomitant antifibrinolytics.

Factor IX↗

PubMed2001

Bupivacaine wound instillation via an electronic patient-controlled analgesia device and a double-catheter system does not decrease postoperative pain or opioid requirements after major abdominal surgery.

UNLABELLED: To assess the analgesic efficacy of patient-controlled bupivacaine wound instillation, 50 patients undergoing major intraabdominal surgery were enrolled into this prospective, placebo-controlled, double-blinded study. In all cases, a standard general anesthetic was administered. On completion of surgery, two multihole 20-gauge epidural catheters were tunneled through the proximal and distal apices of the surgical wound and placed above the fascia such that the tips were at the margin of the first and second thirds of the surgical wound, respectively. Postoperatively, a patient-controlled analgesia (PCA) device was connected to the instillation system. Either bupivacaine 0.25% (Bupivacaine Group) or an equal volume of sterile water (Control Group) was administered. The PCA device was programmed to deliver 9.0 mL with a 60-min lockout interval and no basal infusion. During the first six postoperative hours, a coinvestigator administered "rescue" morphine (2 mg IV). Thereafter, meperidine 1 mg/kg IM was administered on patient request for additional analgesia. Instillation attempts and actual number of injections were similar between the groups. The mean number of pump infusions and the mean "rescue" opioid requirements during the 24-h study period were similar between the groups. The total "rescue" morphine administered during the first six postoperative hours was 16 +/- 17 mg vs 18 +/- 14 mg for the Bupivacaine and Control Groups, respectively. The total meperidine administered during this period was 1.6 +/- 1.4 mg/kg and 2 +/- 1.2 mg/kg for the Bupivacaine and Control Groups, respectively. Preoperatively, hourly for the first six postoperative hours, and on removal of the instillation catheter, patient-generated visual analog scales for pain were similar at rest, on coughing, and after leg raise. In conclusion, bupivacaine wound instillation via an electronic PCA device and a double-catheter system does not decrease postoperative opioid requirements after surgery performed through a midline incision. IMPLICATIONS: After major abdominal surgery performed through a 20-cm incision, repeated 0.25% bupivacaine wound instillation via an electronic patient-controlled analgesia device and a double-catheter system does not decrease postoperative pain or opioid requirements.

Abdomen↗

PubMed2001

The analgesic efficacy of patient-controlled bupivacaine wound instillation after total abdominal hysterectomy with bilateral salpingo-oophorectomy.

UNLABELLED: To assess the effect of local anesthetic wound instillation on visceral and somatic pain, we studied 36 patients undergoing total abdominal hysterectomy and bilateral salpingo-oophorectomy. A standard general anesthetic was administered. On completion of the operation, a multiorifice 20-gauge epidural catheter was placed above the superficial abdominal fascia such that the tip was at the midpoint of the surgical wound. After surgery, either bupivacaine 0.25% (Bupivacaine group) or sterile water (Control group) was administered via a patient-controlled analgesia device programmed to deliver 9.0 mL with a 60-min lockout interval. During the first 6 h after surgery, rescue IV morphine (2 mg) was administered every 10 min until a visual analog scale score of <30 mm was achieved. Thereafter, on patient request, rescue meperidine 1 mg/kg IM was administered. When compared with the Control group, significantly (P < 0.001) less rescue analgesia was administered to patients in the Bupivacaine group. Rescue morphine administered during the first 6 h after surgery was 6 +/- 4 mg versus 12 +/- 6 mg (P < 0.001) for the Bupivacaine and Control groups, respectively. Rescue meperidine administered was 29 +/- 37 mg versus 95 +/- 36 mg (P < 0.001) for the Bupivacaine and Control groups, respectively. Nausea and antiemetic drug administration was significantly (P = 0.003) less in the Bupivacaine group. Pain scores were similar between the groups. Patient satisfaction was significantly (P = 0.04) more in the Bupivacaine group. We conclude that bupivacaine wound instillation decreases opioid requirements and nausea in the first 24 h after total abdominal hysterectomy with bilateral salpingo-oophorectomy. IMPLICATIONS: Bupivacaine instillation via an electronic patient-controlled analgesia device provides effective analgesia after total abdominal hysterectomy with bilateral salpingo-oophorectomy.

Adult↗

PubMed2001

Renal cell carcinoma: evaluation of the 1997 TNM system and recommendations for follow-up after surgery.

OBJECTIVE: We evaluated the tumor recurrence pattern after radical or nephron-sparing surgery for localized renal cell carcinoma. Based on this pattern, we suggest a surveillance protocol after surgery. METHODS: The outcome of 200 consecutive patients with localized renal cell carcinoma (RCC) that were operated on between January 1982 and December 1997 was evaluated retrospectively. Radical nephrectomy was performed in 155 patients (77.5%), and nephron-sparing surgery in 45 patients (22.5%). The timing and site of disease recurrence were correlated with parameters of the primary tumor. RESULTS: One hundred and twenty-four patients (62%) had pathological stage T1, 26 (13%) had stage T2, and 50 (25%) had stage T3 (41 stage T3a, 8 stage T3b, and 1 stage T3c). The mean follow-up was 47 months (range 6--169 months). Four patients (3.2%) with stage T1, 6 patients (23%) with T2, and 13 patients (26%) with T3 developed recurrent disease. None of the patients with a stage T1 tumor, smaller than 4 cm, had tumor recurrence. There were no recurrences after nephron-sparing surgery compared to 23 recurrences (14.8%) among patients after radical nephrectomy (p = 0.01). Only 1 patient who underwent pulmonary lobectomy for asymptomatic metastases smaller than 2.5 cm, found by routine chest CT, attained long-term survival. CONCLUSIONS: The prognosis of patients after radical nephrectomy for renal cell carcinoma, smaller than 4 cm, is excellent and they do not need radiological follow-up. Patients with larger T1 tumors, 4--7 cm in diameter, or a higher stage should be followed with CT of the chest and abdomen done every 6 months for 5 years and then annually. Following partial nephrectomy of small renal tumors periodic renal ultrasonography should be done to rule out local recurrence in the operated kidney.

Adult↗

PubMed2001

Is the pediatric ureter as efficient as the adult ureter in transporting fragments following extracorporeal shock wave lithotripsy for renal calculi larger than 10 mm.?

PURPOSE: We determined whether the thin ureter of the young child transports stone fragments after extracorporeal shockwave lithotripsy (ESWL) as efficiently as the adult ureter does. This determination was done by comparing the outcome after lithotripsy of renal stones greater than 10 mm. between young children and adults. MATERIALS AND METHODS: Our study group consisted of 38 children 6 months to 6 years old (median 3 years) with renal stones greater than 10 mm. in diameter. This group was further divided into 3 subgroups according to the longest stone diameter on plain abdominal film. There were 21 children with a renal stone diameter of 10 to 15 mm. (subgroup 1), 8, 16 to 20 mm. (subgroup 2) and 9 greater than 20 mm. (subgroup 3). The control group consisted of 38 adults older than 20 years randomly selected from the local ESWL registry. Each adult was matched with a child regarding stone diameter and localization. The control group was similarly divided into subgroups 1a, 2a and 3a. ESWL was performed with the unmodified Dornier HM-3 lithotriptor (Dornier Medical Systems, Inc., Marietta, Georgia). The stone-free rate, complication rate, and need for tubes, including stent or nephrostomy, and greater than 1 ESWL session were compared. RESULTS: The stone-free rate was 95% in the study and 78.9% in the control group (p = 0.086). Stone-free rates were 95%, 100% and 89% in subgroups 1, 2 and 3, and 95%, 65% and 56% in subgroups 1a, 2a and 3a, respectively. There were 10 children and 4 adults who underwent greater than 1 ESWL session (p = 0.14). Then there were 10 children and 6 adults who required a tube before ESWL (p = 0.04), and almost all of them were included in subgroups 3 and 3a. Early complications were rare in both the study and control groups. Late complications had included 2 cases of Steinstrasse in the control and none in the study group. CONCLUSIONS: The stone-free rate after ESWL for large renal stones is higher in young children compared to adults with matching stone size. Renal stones greater than 20 mm. often require more than 1 ESWL session. The pediatric ureter is at least as efficient as the adult for transporting stone fragments after ESWL.

Child↗

PubMed2000

Study of charmless hadronic B meson decays to pseudoscalar-vector final states.

We report results of searches for charmless hadronic B meson decays to pseudoscalar( pi(+/-), K+/-, pi(0), or K(0)(S))-vector( rho, K(*), or omega) final states. By using 9.7x10(6) BB pairs collected with the CLEO detector, we report the first observation of B(-)--->pi(-)rho(0), B(0)-->pi(+/-)rho(-/+), and B(-)-->pi(-)omega, which are expected to be dominated by hadronic b-->u transitions. The measured branching fractions are (10.4(+3.3)(-3.4)+/-2.1)x10(-6), (27.6(+8.4)(-7.4)+/-4.2)x10(-6), and (11.3(+3.3)(-2.9)+/-1. 4)x10(-6), respectively. Branching fraction upper limits are set for all of the other decay modes investigated.

Journal Article↗

PubMed2000

Measurement of charge asymmetries in charmless hadronic B meson decays.

We search for CP-violating charge asymmetries (alpha(CP)) in the B meson decays to K(+/-)pi(-/+), K(+/-)pi(0), K(0)(S)pi(+/-), K(+/-)eta('), and omega pi(+/-). Using 9.66 million upsilon(4S) decays collected with the CLEO detector, the statistical precision on alpha(CP) is in the range of +/-0.12 to +/-0.25 depending on decay mode. While CP-violating asymmetries of up to +/-0.5 are possible within the standard model, the measured asymmetries are consistent with zero in all five decay modes studied.

Journal Article↗

PubMed2000

Search for CP violation in B+/- --> J/psiK+/- and B+/- --> psi(2S)K+/- decays.

We present a search for direct CP violation in B+/--->J/psiK+/- and B+/--->psi(2S)K+/- decays. In a sample of 9.7x10(6) B&Bmacr; meson pairs collected with the CLEO detector, we have fully reconstructed 534 B+/--->J/psiK+/- and 120 B+/--->psi(2S)K+/- decays with very low background. We have measured the CP-violating charge asymmetry to be [+1.8+/-4.3(stat)+/-0.4(syst)]% for B+/--->J/psiK+/- and [+2.0+/-9. 1(stat)+/-1.0(syst)]% for B+/--->psi(2S)K+/-.

Journal Article↗