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P Ko

Publications and source records attributed to P Ko.

At least 19 recordsLinked to original sources
PubMed2003

Bd-->phi KS CP asymmetries as an important probe of supersymmetry.

The decay B(d)-->phi K(S) is a special probe of physics beyond the standard model (SM), since it has no SM tree level contribution. Motivated by recent data suggesting a deviation from the SM for its time-dependent CP asymmetry, we examine supersymmetric explanations. Chirality preserving contributions are generically small, unless gluino is relatively light. Higgs contributions are also too small to explain a large asymmetry. Chirality flipping LR and RL gluino contributions actually can provide sizable effects without conflict with all related results. We discuss how various insertions can be distinguished, and argue the needed sizes of mass insertions are reasonable.

Journal Article↗
PubMed2002

Implications on supersymmetry-breaking mediation mechanisms from observing Bs-->mu+mu- and the muon g-2.

We consider B(s)-->mu(+)mu(-) and the muon (g-2)(mu) in various supersymmetry-breaking mediation mechanisms. If the decay B(s)-->mu(+)mu(-) is observed at Tevatron Run II with a branching ratio larger than approximately 2 x 10(-8), the noscale supergravity (including the gaugino mediation), the gauge mediation scenario with a small number of messenger fields and low messenger scale, and a class of anomaly mediation scenarios will be excluded, even if they can accommodate a large muon (g-2)(mu). On the other hand, the minimal supergravity scenario and similar mechanisms derived from string models can accommodate this observation.

Journal Article↗
PubMed1999

A prospective study of elective stenting in unprotected left main coronary disease.

The standard treatment of left main coronary artery (LMCA) disease has been bypass surgery (CABG). Recent reports suggested that stenting of LMCA disease might be feasible. From January 1995 to April 1998, we carried out a prospective study of elective stenting of unprotected LMCA disease to evaluate its immediate and long-term results. Of 61 consecutive patients with unprotected LMCA disease, 6 were excluded. Acute procedural success was 100% for the remaining 55 patients, without any complications such as stent thrombosis, myocardial infarction, CABG, or death. During a mean follow-up of 16.1+/-9.6 months, 11 patients (20%) had symptomatic recurrence, between 2 to 6 months after their procedure. Seven patients underwent CABG, two had repeat intervention, one continued with medical therapy, and one died before planned angiography. There was no late sudden death. Forty-four patients (80%) remained asymptomatic. We conclude that elective stenting may be a safe alternative to CABG in unprotected LMCA disease.

Aged↗
PubMed1998

Combined use of intraoperative lymphatic mapping and lymphoscintigraphy in the management of squamous cell cancer of the vulva.

BACKGROUND: The standard care of the patient with squamous cell cancer of the vulva is radical vulvectomy along with inguinal-femoral node dissection. We explored the feasibility of sentinel lymphadenectomy in patients with squamous cell cancer of the vulva. METHODS: Patients with biopsy proven squamous cell cancer of the vulva were studied with preoperative lymphoscintigraphy, intraoperative lymphatic mapping with isosulfan blue combined with intraoperative lymphoscintigraphy utilizing a hand-held gamma counter. RESULTS: Five patients with invasive squamous cell cancer were studied. Sentinel nodes were identified in six lymphatic basins. One lymphatic basins had two sentinel nodes. Six of seven sentinel nodes were blue and all retained radioactivity at a ratio of at least 3:1 above the background levels in the regional node basin. One patient was found to have metastatic tumor which was confined to a sentinel lymph node. There was minimal morbidity associated with the procedure. CONCLUSIONS: Lymphatic mapping is feasible in patients with squamous cell cancer of the vulva. These initial results suggests further study is warranted.

Carcinoma, Squamous Cell↗
PubMed1998

Ultrasound characteristics of breast carcinoma.

Recent advances in ultrasound technology, such as the use of high-frequency linear transducers, color flow Doppler, and computer-enhanced imaging, have improved the diagnostic utility of ultrasound. The following retrospective study was performed to evaluate the efficacy of sonographic signs of malignancy and to compare sonography to mammography in 157 patients with palpable, biopsy-proven breast carcinomas. The mammogram reports and sonograms were all reviewed. The grade of each mammogram was recorded using the American College of Radiology mammogram grading scale. All sonograms were reviewed and assigned a score using an adaptation of this scale. Of 157 lesions, 121 were read as suspicious or probable malignancies on mammogram. Thirty-three lesions were read as benign or normal on mammogram. Three patients did not receive mammograms. All 157 lesions were read as either suspicious or probably malignant on ultrasound. Using the 16 described criteria, high-definition sonography complements mammography and appears to be a sensitive modality in the evaluation of palpable biopsy-proven breast malignancies. The diagnostic utility of ultrasound will likely be most important in the evaluation of nonpalpable breast masses; however, a prospective randomized trial will need to be performed.

Biopsy↗
PubMed1996

Elective stenting of unprotected left main coronary disease.

For the 12-mo period of 1995, we encountered seven consecutive patients with symptomatic unprotected left main coronary stenosis requiring revascularization. There were five males and two females, age ranging 48-76 years. One patient was referred to coronary bypass surgery. Of the remaining six patients, three refused surgery and the other three, including one with previous bypass surgery and two with previous interventional procedures, preferred percutaneous revascularization. All six had successful elective stenting of their left main coronary stenoses with the new short Palmaz-Schatz stents, P084 and PS104. There were no complications and all remained totally asymptomatic at 3-14 months followup. We conclude that with proper patient selection and the availability of appropriate stents, elective stenting of unprotected left main coronary stenosis is safe with good immediate and medium term results.

Aged↗
PubMed1996

Early clinical experience with the Multi-Link coronary stent.

The Multi-Link coronary stent (Advanced Cardiovascular Systems, Santa Clara, CA) is a balloon expandable stent carved from a stainless steel cylinder and is composed of 12 corrugated rings connected by multiple links. This design gives the stent great flexibility and conformity as well as radial strength. For the 3 month period from November 1995 to January 1996, all patients undergoing stent implantation in our institution were treated with this device, except for vessels smaller than 2.7 mm or larger than 3.7 mm in diameter, left main disease, or those who could not tolerate anticoagulation therapy. Forty patients, with a total of 42 arteries or 44 lesions, were treated with 56 stents, or 1.33 stents per artery. Clinical presentation included stable angina in 13 (32.5%), unstable angina in 24 (60%), acute myocardial infarction in 2 (5%), of whom 1 was in cardiogenic shock, and atypical symptoms with an abnormal thallium stress test in 1 (2.5%). According to the American College of Cardiology/ American Heart Association (ACC/AHA) classification, 8 lesions (18%) were type A, 14 (32%) type B1, 11 (25%) type B2, and 11 (25%) type C. Forty-three lesions (97.7%) were de novo and 1 (2.3%) restenotic. Stent delivery was successful in all patients. Complications included 1 balloon rupture at 7 atm but without sequelae, and 2 patients in whom the coronary guide wire became kinked and locked inside the catheter shaft of the stent delivery system but stent delivery was eventually successful. Mean diameter stenosis was reduced from 76 +/- 13% presenting to 2 +/- 9% poststenting and minimal lumen diameter increased from 0.87 +/- 0.38 to 2.82 +/- 0.34 mm. There were no acute-subacute stent thromboses, bleeding/vascular complications, or major cardiac events such as myocardial infarction, coronary artery bypass surgery, or death during a follow-up period of 2-5 months (mean 3.6 months). In conclusion, our early clinical experience with the Multi-Link stent is very encouraging, with a very high rate of successful delivery and minimal complications.

Adult↗