Biomedical subjects

D Peterson

Publications and source records attributed to D Peterson.

At least 37 records · Page 2Linked to original sources

PubMed2005

The management of midline transcranial nasal dermoid sinus cysts.

The most common congenital midline nasal masses are nasal dermoid sinus cysts (NDSC) [Hughes GB, Sharpino G, Hunt W, Tucker HM. Management of the congenital midline nasal mass--a review. Head Neck Surg 1980;2:222-33.]. Their clinical importance hinges on their potential to communicate with the central nervous system. Preoperative diagnosis of an intracranial extension allows for referral to a craniofacial team with the appropriate skills and experience for a transcranial approach. All patients with a NDSC require imaging with high resolution multiplanar MRI scans and complimentary fine cut CT scan to reveal the anatomical extent of the tract and its relationship to the anterior cranial fossa. A single-stage craniofacial approach to resection of midline NDSC extending to the anterior cranial base is effective with minimal morbidity [Yavuzer R, Bier U, Jackson IT. Be careful: it might be a nasal dermoid cyst. Plast Reconstr Surg 1999;103:2082-3; Denoyelle F, Ducroz V, Roger G, Garabedian EN. Nasal dermoid sinus cysts in children. Laryngoscope 1997;107:795-800; Rohrich RJ, Lowe JB, Schwartz MR. The role of open rhinoplasty in the management of nasal dermoid cysts. Plast Reconstr Surg 1999;104:2163-70; Rahbar R, Shah P, Mulliken JB, et al. The presentation and management of nasal dermoid-a 30-year experience. Arch Otolaryngol Head Neck Surg 2003;129:464-71; Posnick JC, Bortoluzzi P, Armstrong DC, Drake JM. Intracranial nasal dermoid sinus cysts: computed tomographic scan findings and surgical results. Plast Reconstr Surg 1994;93:745-54 [discussion 755-56]; Bartlett SP, Lin KY, Grossman R, Kratowitz J. The surgical management of orbitofacial dermoids in the pediatric patient. Plast Reconstr Surg 1993;91:1208-15.]. The cyst and tract are accessed through a combination of a nasal and transcranial approach. This allows visualisation and dissection of the tract with only a small incision on the nasal dorsum to include the cutaneous punctum when present. Transnasal endoscopic techniques have been advocated where the dermoid is located within the nasal cavity and there is little or no cutaneous involvement [Weiss DD, Robson CD, Mulliken JB. Transnasal endoscopic excision of midline nasal dermoid from the anterior cranial base. Plast Reconstr Surg 1998;101:2119-23.]. We present a review of five cases referred to our unit between 1999 and 2004 with a diagnosis of a midline nasal dermoid sinus cyst and radiological evidence of intracranial communication. All cases had a communication with the anterior cranial fossa diagnosed preoperatively and were treated surgically with a craniofacial approach. An intracranial extension was identified at operation in each case and this was confirmed on histopathology. The only significant complication resulted from an early postoperative infection, requiring re-operation. There were no recurrences and acceptable aesthetic outcomes have been observed in all cases.

Bone Diseases↗

PubMed2005

Observation of thirteen new exclusive multibody hadronic decays of the psi(2S).

Using data accumulated with the CLEO detector corresponding to an integrated luminosity of [symbol: see text] = 5.63 pb(-1) on the peak of the psi(2S) [3.08 x 10(6) psi(2S) decays] and 20.70 pb(-1) at square root of[s] = 3.67 GeV, we report first measurements of the branching fractions for the following 13 decay modes of the psi(2S): eta3pi, &eta'3pi, rhoK+K-, K+K-pi+pi-pi0, 2(K+K-), 2(K+K-)pi0, rhopp, pppi+pi-pi0, etapp, ppK+K-, lambdalambdapi+pi-, lambdapK+, and lambdapK+pi+pi-, and more precise measurements of 8 previously measured modes: 2(pi+pi-), rhopi+pi-, 2(pi+pi-)pi0, omegapi+pi-, K+K-pi+pi-, omegaK+K-, phiK+K-, and pppi+pi-. We also report new branching fraction measurements of phipi+pi- and omegapp and upper limits for etapi+pi-, etaK+K-, and phivpp. Results are compared, where possible, with the corresponding J/psi branching ratios to provide new tests of the 12% rule.

Journal Article↗

PubMed2005

Ground state proton radioactivity from 121Pr: when was this exotic nuclear decay mode first discovered?

Ground-state proton radioactivity has been identified from 121Pr. A transition with a proton energy of E(p)=882(10) keV [Q(p)=900(10) keV] and half-life t(1/2)=10(+6)(-3) ms has been observed and is assigned to the decay of a highly prolate deformed 3/2(+) or 3/2(-) Nilsson state. The present result is found to be incompatible with a previously reported observation of ground-state proton radioactivity from 121Pr, which would have represented the discovery of this phenomenon.

Journal Article↗

PubMed2005

Branching fractions for psi(2S)-to-J/psi transitions.

We describe new measurements of the inclusive and exclusive branching fractions for psi(2S) transitions to J/psi using e(+)e(-) collision data collected with the CLEO detector operating at CESR. All branching fractions and ratios of branching fractions reported here represent either the most precise measurements to date or the first direct measurements. Indirectly and in combination with other CLEO measurements, we determine B(chi(cJ) --> gamma(J/psi)) and B[psi(2S) --> light hadrons].

Journal Article↗

PubMed2005

Improved measurement of the form factors in the decay lambda+c-->lambda + nue.

Using the CLEO detector at the Cornell Electron Storage Ring, we have studied the distribution of kinematic variables in the decay lambda(+)(c)lambda--> e(+)nu(e). By performing a four-dimensional maximum likelihood fit, we determine the form factor ratio, R= f(2)/f(1) = -0.31 +/- 0.05(stat) +/- 0.04(syst), the pole mass, M(pole) = [2.21 +/- 0.08(stat) +/- 0.14(syst)] GeV/c(2), and the decay asymmetry parameter of the lambda(+)(c), alpha (lambda(c)) = -0.86 +/-0.03(stat) +/- 0.02(syst), for q(2) = 0.67 (GeV/c(2))(2). We compare the angular distributions of the lambda(+)(c) and lambda(-)(c) and find no evidence for CP violation: A(lambda(c)) = (alpha(lambda(c)) + alpha (lambda(c)))/(alpha(lambda(c))-alpha(lambda(c))) = 0.00 +/- 0.03(stat) +/- 0.01(syst) +/- 0.02, where the third error is from the uncertainty in the world average of the CP-violating parameter, A(lambda), for ppi(-).

Journal Article↗

PubMed2005

Neutron spectroscopic factors in 9Li from 2H(8Li,p)9Li.

We have studied the 2H(8Li,p)9Li reaction to obtain information on the spins, parities, and single-neutron spectroscopic factors for states in 9Li, using a radioactive 8Li beam. The deduced properties of the lowest three states are compared to the predictions of a number of calculations for the structure of 9Li. The results of ab initio quantum Monte Carlo calculations are in good agreement with the observed properties.

Journal Article↗

PubMed2005

Search for X(3872) in gammagamma fusion and radiative production at CLEO.

We report on a search for the recently reported X(3872) state using 15.1 fb(-1) of e(+)e(-) data taken in the sqrt[s] = 9.46-11.30 GeV region. Separate searches for the production of the X(3872) in untagged gammagamma fusion and e(+)e(-) annihilation following initial state radiation are made by taking advantage of the unique angular correlation between the leptons from the decay J/psi --> l(+)l(-) in X(3872) decay to pi(+)pi(-)J/psi. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)Gamma(gammagamma)(X(3872))B(X --> pi(+)pi(-)J/psi) < 12.9 eV and Gamma(ee)(X(3872))B(X- -> pi(+)pi(-)J/psi) < 8.3 eV.

Journal Article↗

PubMed2005

Photon transitions in Upsilon(2S) and Upsilon(3S) decays.

We have studied the inclusive photon spectra in Upsilon(2S) and Upsilon(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates and photon energies for Upsilon(2S) --> gammachi(bJ)(1P) and Upsilon(3S) --> gammachi(bJ)(2P) (J = 0, 1, 2). We measure the rate for a rare E1 transition Upsilon(3S) --> gammachi(b0)(1P) for the first time. We also set upper limits on the rates for the hindered magnetic dipole (M1) transitions to the eta(b)(1S) and eta(b)(2S) states.

Journal Article↗

PubMed2005

Observation of 1(-)0(-) final states from psi(2S) decays and e(+)e(-) annihilation.

Using CLEO data collected from CESR e(+)e(-) collisions at the psi(2S) resonance and nearby continuum at sqrt[s]=3.67 GeV, we report the first significantly nonzero measurements of light vector-pseudoscalar hadron pair production (including rhopi, omegapi, rhoeta, and K(*0)K0 ) and the pi(+)pi(-)pi(0) final state, both from psi(2S) decays and direct e(+)e(-) annihilation.

Journal Article↗

PubMed2005

Study of the semileptonic charm decays D(0)-->pi(-)l(+)nu and D(0)-->K(-)l(+)nu.

We investigate the decays D(0)-->pi(-)l(+)nu and D(0)-->K(-)l(+)nu, where l is e or mu, using approximately 7 fb(-1) of data collected with the CLEO III detector. We find R(0) identical with B(D(0)-->pi(-)e(+)nu)/B(D(0)-->K(-)e(+)nu)=0.082+/-0.006+/-0.005. Fits to the kinematic distributions of the data provide parameters describing the form factor of each mode. Combining the form factor results and R(0) gives |f(pi)(+)(0)|(2)|V(cd)|(2)/|f(K)(+)(0)|(2)|V(cs)|(2)=0.038(+0.006+0.005)(-0.007-0.003).

Journal Article↗

PubMed2005

Measurement of the muonic branching fractions of the narrow upsilon resonances.

The decay branching fractions of the three narrow Upsilon resonances to mu(+)mu(-) have been measured by analyzing about 4.3 fb(-1) e(+)e(-) data collected with the CLEO III detector. The branching fraction B(Upsilon(1S)-->mu(+)mu(-))=(2.49+/-0.02+/-0.07)% is consistent with the current world average, but B(Upsilon(2S)-->mu(+)mu(-))=(2.03+/-0.03+/-0.08)% and B(Upsilon(3S)-->mu(+)mu(-))=(2.39+/-0.07+/-0.10)% are significantly larger than prior results. These new muonic branching fractions imply a narrower total decay width for the Upsilon(2S) and Upsilon(3S) resonances and lower other branching fractions that rely on these decays in their determination.

Journal Article↗

PubMed2005

Lowering the dose of hydroxyurea minimizes toxicity and maximizes anti-HIV potency.

The goal of this study was to optimize the hydroxyurea dosage in HIV-infected patients, and to minimize the toxicity and maximize the antiviral efficacy of the hydroxyurea-didanosine combination. In a randomized, open-label study (RIGHT 702, a multicenter trial performed in private and institutional practices), three daily doses (600 microg, 800-900 microg, and 1200 microg) of hydroxyurea were administered in combination with didanosine and stavudine to 115 chronically HIV-infected patients, one-third antiretroviral drug naive, with viremia between 5000 and 200,000 copies/ml regardless of CD4+ cell count. The primary efficacy end point was the proportion of patients with plasma HIV-1 RNA levels below 400 copies/ml after 24 weeks of therapy. In the RIGHT 702 intent-to-treat population the lowest (600 mg) dose of hydroxyurea was better tolerated, associated with fewer adverse events, and more potent by all efficacy parameters, including the primary end point (76 versus 60% patients with viremia<400 copies/ml at week 24 for the 600-mg and 800- to 900-mg dose groups, respectively; p=0.027), the mean area under the curve (60.3 versus 65.8; p=0.016), and the mean log10 decrease (-1.95 versus -0.77; p=0.001). Patients receiving 600 mg of hydroxyurea daily also had the highest CD4+ cell count, CD4+/CD8+ cell ratio, and lowest CD8+ cell count and percentage (p=0.035). The RIGHT 702 trial provides an explanation for the increased toxicity and decreased efficacy of hydroxyurea when it was used at high dosage (1200 mg daily). At the optimal dosage of 600 mg daily, hydroxyurea, in combination with didanosine, deserves reevaluation for the long-term management of HIV/AIDS worldwide, because of its excellent resistance profile, durability, and affordability.

Anti-HIV Agents↗

PubMed2005

Late onset neonatal anaemia due to maternal anti-Ge: possible association with destruction of eythroid progenitors.

There have been no reports of severe haemolytic disease of the newborn (HDN) due to Gerbich (Ge) antibodies. Two babies with HDN due to anti-Ge3, both born to the same mother, are described. The anti-Ge appeared in the first pregnancy and was not detectable in the first trimester, the babies' reticulocyte and bilirubin values were not greatly elevated (similar to HDN due to Kell antibodies), and the anaemia in both cases was either not apparent or not severe until 2 to 4 weeks after birth. Ge antigens are found on glycophorins (GPs) C and D; GPC, like Kell, has been shown to be expressed early on erythroid progenitor cells. The maternal anti-Ge3 was shown to promote phagocytosis of Ge+ early erythroid progenitors by monocytes (similar to what has been reported with anti-K and K+ progenitor cells). Thus, anti-Ge3 may cause immune destruction of erythroid progenitors and possibly suppression of erythropoiesis (which would explain the reticulocyte and bilirubin values seen in both cases). Anti-Ge3 appears to be capable of causing severe HDN. We suggest that babies born to mothers with anti-Ge should have their haemoglobin concentrations monitored for signs of anaemia for several weeks after birth. Functional assays may prove useful.

Anemia, Hemolytic↗

PubMed2005

The role of diet, exercise and smoking in dyslipidaemia in HIV-infected patients with lipodystrophy.

BACKGROUND: Lipodystrophy in HIV-infected (LDHIV) patients receiving protease inhibitors (PIs) is associated with dyslipidaemia. Whether lifestyle factors play a role in dyslipidaemia in LDHIV subjects on PIs is not well characterized. METHODS: A total of 45 LDHIV male and six LDHIV female patients on PIs were recruited, and data were collected on smoking, exercise, diet (by 3-day food record), and fasting levels of serum lipids and lipoproteins. The relationships between lifestyle factors and metabolic variables were analysed in male patients by Spearman's correlation test and the significant relationships were further analysed by adjusting for age, PI duration, and waist circumference by Spearman's partial correlation test. RESULTS: In men, mean (+/-standard deviation) serum concentrations of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and non-HDL-C were 212+/-70, 35+/-7.3, 325+/-230 and 169+/-44 mg/dL, respectively. Sixty-seven percent of the men exercised regularly and 31.1% smoked. The reported diet was high in cholesterol (390+/-212 mg) and percentage energy from saturated (12.2+/-3.3%) and trans (2.4+/-1.2%) fats, and low in soluble fibre (6.9+/-2.3 g) compared with recent dietary guidelines. Following adjustments for the confounding variables, percentage energy intake from total protein and animal protein was positively related to TC (r=0.44, P<0.01 and r=0.37, P<0.05, respectively), TG (r=0.40, P<0.01 and r=0.46, P<0.01, respectively) and non-HDL-C (r=0.56, P<0.001 and r=0.49, P<0.01, respectively), that from trans fat was positively related to TG (r=0.34, P<0.05), and soluble fibre was negatively related to non-HDL-C (r=-0.41, P<0.01). Moderate to heavy aerobic exercise tended to be associated with higher HDL-C (r=0.30, P=0.07) whereas smoking was not associated with any of the metabolic variables. CONCLUSIONS: Increased intake of total protein, animal protein and trans fat, and reduced soluble fibre consumption contribute to dyslipidaemia in LDHIV subjects on PIs.

Adult↗

PubMed2004

Search for the lepton-flavor-violating leptonic B(0)-->mu(+/-)tau(-/+) and B(0)-->e(+/-)tau(-/+).

We have searched a sample of 9.6 x 10(6) BB events for the lepton-flavor-violating leptonic B decays, B(0)-->mu(+/-)tau(-/+) and B(0)-->e(+/-)tau(-/+). The tau lepton was detected through the decay modes tau-->lnunu(-) , where l=e, mu. There is no indication of a signal, and we obtain the 90% confidence level upper limits B(B(0)-->mu(+/-)tau(-/+))<3.8 x 10(-5) and B(B(0)-->e(+/-)tau(-/+))<1.3 x 10(-4).

Journal Article↗

PubMed2004

A knot in the catheter--an unusual cause of ventriculo-peritoneal shunt blockage.

A 25-year-old woman, who was 25 weeks pregnant, underwent insertion of a VP shunt for hydrocephalus, secondary to a bithalamic glioma. Two months later, she represented with symptoms of raised intracranial pressure and MR scan revealed increased ventricular size. On exploration of the shunt, manometry with saline confirmed blockage of the catheter distal to the valve. On re-opening the abdominal wound, the peritoneal catheter was found to be knotted, 2 cm from the end. This segment of the catheter was replaced, with resolution of symptoms, post-operatively. The present case illustrates that a knot in the peritoneal catheter is an extremely rare cause of shunt malfunction. Possible mechanisms underlying it are discussed.

Adult↗

PubMed2004

Wess-Zumino current and the structure of the decay tau- -->K- pi- K+ nu tau.

We present the first study of the vector (Wess-Zumino) current in tau(-)-->K-pi-K+nu(tau) decay using data collected with the CLEO III detector at the Cornell Electron Storage Ring. We determine the quantitative contributions to the decay width from the vector and axial vector currents. Within the framework of a model by Kühn and Mirkes, we identify the quantitative contributions to the total decay rate from the intermediate states omegapi, rho(')pi, and K*K.

Journal Article↗

PubMed2004

Observation of the Hadronic transitions chi(b1,2)(2P)-->omegaUpsilon(1S).

The CLEO Collaboration has made the first observations of hadronic transitions among bottomonium (bbmacr;) states other than the dipion transitions among Upsilon(nS) states. In our study of Upsilon(3S) decays, we find a significant signal for Upsilon(3S)-->gammaomegaUpsilon(1S) that is consistent with radiative decays Upsilon(3S)-->gammachi(b1,2)(2P), followed by chi(b1,2)(2P)-->omegaUpsilon(1S). The branching ratios we obtain are B[chi(b1)(2P)-->omegaUpsilon(1S)]=(1.63(+0.35+0.16)(-0.31-0.15))% and B[chi(b2)(2P)-->omegaUpsilon(1S)]=(1.10(+0.32+0.11)(-0.28-0.10))%, in which the first error is statistical and the second is systematic.

Journal Article↗