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Biomedical subjects

K B Lee

Publications and source records attributed to K B Lee.

At least 37 records · Page 2Linked to original sources

Hickman catheter site infections after allogeneic stem cell transplantation: a single-center experience.

Hickman catheter site infections are known to increase transplant-related mortality. A retrospective analysis of 103 patients who received allogeneic stems cell transplants was performed to define the incidence and outcomes of Hickman infections. Seventy-six patients received peripheral blood stem cells (PBSC) (73.8%) and 29 patients (28.2%) nonmyeloablative conditioning. During the median follow-up of 9 months, Hickman infections were observed in 10 patients (9.7%) at a median onset of 32 days posttransplant (range 2 to 102 days). The causative organisms identified in five cases included Staphylococcus species (n = 4) and Pseudomonas aeruginosa (n = 1). Six events successfully resolved with antibiotic treatment, while the other four required the removal of the Hickman catheter with subsequent death in two cases. The survival duration for infected patients was shorter than that for the noninfected group (83 days vs 366 days, P < .001). Myeloid engraftment was delayed in the infected group (18.0 days vs 15.0 days, P = .038) and this complication was more frequently observed among the BMT compared with PBSC group (22.2% vs 5.3%, P = .019). Hickman infections were associated with transplant-related mortality especially during the first 3 months posttransplant. As such, the current results emphasize both the importance of Hickman catheter care and the need for surveillance cultures after stem cell transplantation.

Adolescent↗

Hickman catheter site infections after allogeneic stem cell transplantation: single-center experience.

Hickman catheter site infections are known to increase transplant-related mortality (TRM). A retrospective analysis of 103 patients who received allogeneic SCT (stem cell transplants) was performed to define the incidence and outcomes of Hickman infections. Seventy-six patients received peripheral blood stem cells (PBSCs) (73.8%) and 29 patients (28.2%), nonmyeloablative conditioning. During the median follow-up of 9 months, Hickman infections were observed in 10 patients (9.7%) at a median onset of 32 days posttransplantation (range, 2-102 days). The causative organisms were identified in 5 cases, including Staphylococcus species (n=4) and Pseudomonas aeruginosa (n=1). Six events were successfully resolved with antibiotic treatment, whereas the other 4 events required the removal of the Hickman catheters with subsequent death in 2 cases. The survival duration for the Hickman infection group was shorter than that for the Hickman no infection group (83 days vs 366 days, respectively; P <.001). Myeloid engraftment was delayed in the Hickman infection group (18.0 days vs 15.0 days, respectively; P=.038), plus Hickman infections were more frequent among BMT compared with PBSCT group (22.2% vs 5.3%, respectively, P=.019). Hickman infections were associated with TRM, especially during the first 3 months posttransplantation. As such, the current results emphasize both the importance of Hickman catheter care and the need for surveillance cultures after SCT.

Adolescent↗

A pilot study of cytoreductive chemotherapy combined with infusion of additional peripheral blood stem cells reserved at time of harvest for transplantation in case of relapsed hematologic malignancies after allogeneic peripheral blood stem cell transplant.

Reharvesting leukocytes from donors for a donor leukocyte infusion (DLI) is inconvenient and occasionally impossible in case of unrelated donors. It is well known that the effect of a growth factor-primed DLI is comparable to that of a nonprimed DLI. In total, 42 patients with hematologic malignancies and a high risk of relapse were allocated, on an intent-to-treat basis, a peripheral blood stem cell transplantation (PBSCT) from HLA-matched sibling donors, and then at the time of harvest, additional peripheral blood stem cells (PBSCs) were also reserved for a therapeutic primed DLI in case of relapse. In all, 12 patients who relapsed after allogeneic PBSCT were treated with mainly cytarabine-based chemotherapy followed by a cryopreserved PBSC infusion. The median dose of CD3+ and CD34+ cells for the primed DLIs was 1.43 x 10(8)/kg and 4.75 x 10(6)/kg, respectively. Six of the 12 relapsed patients exhibited a complete response after the primed DLI, plus their 1-year survival rate was 33%. The new development or progression of graft-versus-host disease after a primed DLI was observed in 50% of the patients. Overall, the survival at 1 year was 16.7%. Accordingly, the induction of a graft-versus-leukemia effect through a primed DLI, using additional PBSCs reserved at the original time of harvest, would appear to be feasible for patients with relapsed hematologic malignancies. Furthermore, this approach is also more convenient for donors.

Adoptive Transfer↗

Clinical impact of hyperacute graft-versus-host disease on results of allogeneic stem cell transplantation.

The current study defines the incidence and clinical manifestations of hyperacute graft-versus-host disease (haGVHD; fever, skin rash, diarrhea, and hepatic dysfunction) and analyzes the risk factor and the impact of haGVHD on the results of allogeneic stem cell transplantation (SCT). In all, 90 patients underwent allogeneic SCT from 71 matched siblings or 19 alternative donors. Immediate high-dose steroids were administered to 22 patients who met the criteria. The overall incidence of haGVHD was 36.7% (n=34) and haGVHD was also strongly correlated with acute (aGVHD) (P<0.001) and extensive chronic GVHD (cGVHD) (P=0.007), and found to be associated with decreased probability of relapse (P=0.0017). Early intervention with steroids within 7 days after the diagnosis of haGVHD might be associated with better survival. A survival analysis of the overall survival and disease-free survival did not reveal any difference between haGVHD+ and haGVHD- groups. In multivariate analysis, the use of an alternative donor (P=0.020) was identified as the only risk factor. Immediate high-dose steroids were effective in treating haGVHD. We conclude that in an allogeneic setting, haGVHD is not an uncommon manifestation, associated with the development of aGVHD or cGVHD. The only risk factor for haGVHD was the use of an alternative donor.

Adrenal Cortex Hormones↗

Risk factors for late cytomegalovirus infection after allogeneic stem cell transplantation using HLA-matched sibling donor: donor lymphocyte infusion and previous history of early CMV infection.

An increased incidence of late cytomegalovirus (CMV) infection has been reported during the last decade since the introduction of ganciclovir (GCV) prophylaxis or GCV pre-emptive therapy. Given that a donor lymphocyte infusion (DLI) can induce more severe GVHD, this may predispose a patient to late CMV infection. In all, 64 patients (median age 36, M/F 38/26) underwent allogeneic stem cell transplantation (SCT) using a matched sibling donor with bone marrow (n=9) or peripheral blood stem cells (n=55). The overall incidence of CMV infection, early and late CMV infection was 46.9 (30/64), 42.2 (27/64), and 16.4% (9/55), respectively. Early CMV infection was treated with GCV pre-emptive therapy that produced a 92.6% success rate. Among the 20 patients who received 35 DLIs, late CMV infection developed in eight (42.1%) of 19 evaluable cases with a median onset at 127 days post transplant. Risk factors for late CMV infection in a logistic regression analysis included DLIs (P=0.001) and a previous history of CMV infection (P=0.006). In conclusion, late CMV infection was strongly associated with DLIs and a previous history of early CMV infection. Accordingly, extended surveillance of CMV antigenemia is recommended for patients receiving DLIs or who have a previous history of CMV infection.

Adult↗

Transplantation outcome in allogeneic PBSCT patients according to a new chronic GVHD grading system, including extensive skin involvement, thrombocytopenia, and progressive-type onset.

Patients who had suffered chronic GVHD after an allogeneic PBSCT were evaluated using a new chronic GVHD grading system. The study included 36 consecutive adult patients with hematological diseases, who survived at least until day 90 following allogeneic PBSCT and who could be evaluated for chronic GVHD. Extensive skin involvement was observed in five patients, thrombocytopenia in 14, and progressive-type onset in 10, while grade 1 chronic GVHD appeared in 21 patients, grade 2 in 10, and grade 3 in five. There was a significant difference in the probability of relapse between the groups with grade 1 and 2+3 chronic GVHD (55.3 vs 16.4%, P=0.0211). The difference was particularly marked in patients with high-risk hematological malignancies (grade 1 vs grade 2+3, 75 vs 0%, P=0.0115). With a median follow-up of 12 months (range, 4-52 months), 22 (66.1%) patients were still alive. The estimated 2-year survival rate for the whole population was 57.6%, while that for the group with chronic GVHD grade 1 and grade 2+3 was 53.5 and 56.3%, respectively (P=0.4387). Accordingly, there was a significant difference in the probability of relapse between the groups with grade 1 and grade 2+3 chronic GVHD.

Adolescent↗

Increased expression of caveolin-1 and microvessel density correlates with metastasis and poor prognosis in clear cell renal cell carcinoma.

OBJECTIVE: To investigate the relationship of caveolin-1 expression and microvessel density (MVD), a reflection of angiogenesis, with metastasis and prognosis in patients with clear cell renal cell carcinoma (RCC). PATIENTS AND METHODS: Formalin-fixed, paraffin-embedded tissue sections of clear cell RCC from 67 patients who had undergone radical nephrectomy were stained immunohistochemically with specific antibodies against caveolin-1 and CD34. Caveolin-1 immunostaining was semi-quantitatively estimated based on the proportion (percentage of positive cells) and intensity. MVD was determined with CD34-stained slides. The expression pattern of caveolin-1 and MVD was compared with the clinicopathological variables. RESULTS: Eighteen patients had either synchronous or metachronous metastases and 11 died during the follow-up. Caveolin-1 intensity was significantly correlated with tumour size (P = 0.005), TNM stage (P = 0.028), M stage (P = 0.012), grade (P = 0.015), and metastasis (synchronous or metachronous; P < 0.001). The caveolin-1 proportion (P = 0.037) and MVD (P = 0.011) were significantly correlated with metastasis. MVD was correlated with caveolin-1 intensity (r = 0.385, P = 0.001) and caveolin-1 proportion (r = 0.388, P = 0.001). There was no difference in the expression of caveolin-1 and MVD between primary and metastatic sites. The survival of patients with higher caveolin-1 intensity was significantly worse than that of patients with lower caveolin-1 intensity. Multivariate analyses indicated that only M-stage was an independent prognostic factor for cancer-specific survival and caveolin-1 expression was not an independent factor. CONCLUSIONS: Increased expression of caveolin-1 and MVD is associated with metastasis and a worse prognosis in clear cell RCC. Caveolin-1 expression is correlated with MVD. These results suggest that caveolin-1 may be important in the progression of clear cell RCC and angiogenesis may be affected by caveolin-1 during the progression of RCC.

Adult↗

Impact of transplanted CD34+ cell dose in allogeneic unmanipulated peripheral blood stem cell transplantation.

The impact of the CD34+ cell dose on chronic graft-versus-host disease (cGVHD) and the clinical outcome was analyzed in 41 consecutive adult patients submitted to allogeneic peripheral blood stem cell transplantation from HLA-identical siblings. The patients were classified into 'low' or 'high' CD34+ cell dose groups based on whether they received less or more than a median CD34+ cell dose of 10.5 x 10(6)/kg, respectively. There was a significant difference in the incidence of extensive cGVHD (low vs high group, 25.0 vs 66.7%, P=0.021) and relapse (47.6 vs 20.0%, P=0.049) between the two groups. With a median follow-up of 335 days, the 3-year survival estimate for the whole population was 47.9%, while that for the low and high groups was 29.9 and 67.8%, respectively (P=0.0434). An inverse relation was noted between the relapse rate and the incidence of extensive cGVHD (P=0.043). It would appear reasonable that the optimal dose of CD34+ cells should be determined based on the disease status or aggressiveness of the malignant cells in each patient. Yet, in the case of patients with a high risk of relapse, transplantation with a CD34+ cell dose of >10.5 x 10(6)/kg would seem to be acceptable to minimize the risk of relapse.

Adolescent↗

Semi-constrained total elbow arthroplasty in Chinese rheumatoid patients.

Seventeen Coonrad-Morrey semi-constrained total elbow replacements were performed on 14 Chinese rheumatoid patients. The elbows were reviewed retrospectively after a mean follow-up of 36 months (range 12-89 months.) After the operation, all patients were satisfied and there was no pain in 15 elbows. There was no radiological sign of loosening in the implanted prostheses and bone graft was incorporated in 93% of primary elbow replacements. The Mayo Elbow Performance Score was improved from an average of 40 (range 20-75) to an average of 93 (range 65-100). The arc of flexion was improved from an average of 89 degrees (range 0 degrees-125 degrees ) to 104 degrees (range 35 degrees-125 degrees ). The sizes of implants can be predicted accurately by the planning template in only four elbows (24%) and there were early complications in seven elbows (41%), with one prosthesis removed because of deep infection.

Adult↗

Expression of multidrug resistance-associated protein1,P-glycoprotein, and thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection.

Both 5-fluorouracil and doxorubicin are commonly used agents in chemotherapy of gastric cancer in adjuvant setting as well as metastatic disease. In a variety of malignancies, high expression of multidrug resistance-associated protein1 and P-glycoprotein has been associated with resistance to doxorubicin, whereas 5-fluorouracil resistance has correlated with the level of thymidylate synthase expression. We evaluated the expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase using immunohistochemistry in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection and investigated the association between their expression and clinicopathologic characteristics including prognosis of the patients. While high expression (> or =5% of tumour cells positive) of multidrug resistance-associated protein1 and P-glycoprotein was observed in 70 patients (68%) and 42 patients (41%), respectively, 65 patients (63%) had primary tumours with high expression (> or =25% of tumour cells positive) of thymidylate synthase. There was a significant association between multidrug resistance-associated protein1 and P-glycoprotein expression (P<0.0001) as well as P-glycoprotein and thymidylate synthase expression (P<0.0001). High multidrug resistance-associated protein1 and P-glycoprotein expressions were associated with well and moderately differentiated histology (P<0.0001 and P=0.03, respectively) and intestinal type (P<0.0001 and P=0.009, respectively). High multidrug resistance-associated protein1 expression correlated with lymph node metastasis (P=0.037), advanced stage (P=0.015), and older age (P=0.021). Five-year disease-free survival and overall survival of total patients were 55.2% and 56.2%, respectively, with a median follow-up of 68 months. There were no significant differences in disease-free survival and overall survival according to the expression of multidrug resistance-associated protein1 (P=0.902 and P=0.975, respectively), P-glycoprotein (P=0.987 and P=0.955, respectively), and thymidylate synthase (P=0.604 and P=0.802, respectively). Concurrent high expression of these proteins (high multidrug resistance-associated protein1/P-glycoprotein, high multidrug resistance-associated protein1/thymidylate synthase, high P-glycoprotein/thymidylate synthase) did not correlate with disease-free survival or overall survival. Even high expression of all three proteins was not associated with poor disease-free survival (P=0.919) and overall survival (P=0.852). In conclusion, high expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase did not predict poor prognosis of gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy. A larger study including patients treated with surgical resection alone would be necessary.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

A high statistics measurement of the Lambda(+)(c) lifetime.

A high statistics measurement of the Lambda(+)(c) lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis technique with particular attention to the determination of the systematic uncertainty. The measured value of 204.6 +/- 3.4 (stat) +/- 2.5 (syst) fs from 8034 +/- 122 Lambda(+)(c)-->pK(-)pi(+) decays represents a significant improvement over the present world average.

Journal Article↗

Search for CP violation in the decays D+--> K(S)pi+ and D+-->K(S)K+.

A high-statistics sample of photoproduced charm from the FOCUS experiment has been used to search for direct CP violation in the decay rates for D+-->K(S)pi+ and D+-->K(S)K+. We have measured the following asymmetry parameters relative to D+-->K-pi+pi+: A(CP)(K(S)pi+) = (-1.6+/-1.5+/-0.9)%, A(CP)(K(S)K+) = (+6.9+/-6.0+/-1.5)%, and A(CP)(K(S)K+) = (+7.1+/-6.1+/-1.2)% relative to D+-->K(S)pi+. We have also measured the relative branching ratios and found Gamma(D+-->K(0)pi+)/Gamma(D+-->K-pi+pi+) = (30.60+/-0.46+/-0.32)%, Gamma(D+-->K(0)K+)/Gamma(D+-->K-pi+pi+) = (6.04+/-0.35+/-0.30)%, and Gamma(D+-->K(0)K+)/Gamma(D+-->K(0)pi+) = (19.96+/-1.19+/-0.96)%.

Journal Article↗

GM-CSF-based mobilization effect in normal healthy donors for allogeneic peripheral blood stem cell transplantation.

It is important to optimize methods to mobilize hematopoietic stem cells into peripheral blood (PB) for successful allogeneic peripheral blood stem cell (PBSC) transplantation. Our primary intent was to investigate the role of GM-CSF for mobilization in normal healthy donors and to compare its efficacy in mobilizing stem cells alone, in concurrent combination and in sequential combination with G-CSF in this study. We analyzed the results of the PBSC harvest through large volume leukapheresis from 48 normal healthy donors mobilized by three different regimens including GM-CSF. Donors were assigned sequentially to one of the following regimens for mobilization: GM-CSF 10 microg/kg/day alone (group 1, n = 9); concurrent combination (group 2, n = 20) of G-CSF 5 microg/kg/day and GM-CSF 5 microg/kg/day; sequential combination (group 3, n = 19) of GM-CSF alone 10 microg/kg/day for 3 days followed by G-CSF alone 10 microg/kg/day for 2-3 days. The harvested CD34(+) cell count (P < 0.05) was statistically higher in group 3 than in group 1 or 2. Pre-collection WBC count in donors (P < 0.05), harvested MNC (P < 0.05) and CD3(+) cell count (P < 0.05) of group 2 or 3 were significantly higher than those of group 1. Recipients who received stem cells mobilized with combination regimens showed an earlier recovery of WBC and platelets count than those with GM-CSF alone. The incidence of acute graft-versus-host disease was not statistically different among three recipient groups. GM-CSF-based mobilization was well tolerated in normal healthy donors. The sequential combination regimen appears to be an excellent mobilization strategy and might be preferred as the optimal method in some clinical situations that need a higher number of stem cells.

Adult↗

Melasma: histopathological characteristics in 56 Korean patients.

BACKGROUND: Melasma is a common acquired symmetrical hypermelanosis characterized by irregular light to dark brown macules and patches on sun-exposed areas of the skin. Its histopathological characteristics are not fully understood. OBJECTIVES: To characterize the histopathological features of facial melasma skin in comparison with adjacent normal skin. METHODS: Biopsies were taken from both melasma lesional skin and adjacent perilesional normal skin in 56 Korean women with melasma. The sections were stained using haematoxylin and eosin, Fontana-Masson, diastase-resistant periodic acid-Schiff, Masson trichrome and Verhoeff-van Gieson stains, and immunostaining for melanocytes. Data on the changes in number of melanocytes and melanin contents of the epidermis were analysed by a computer-assisted image analysis program. The ultrastructure of the skin was also examined. RESULTS: The amount of melanin was significantly increased in all epidermal layers in melasma skin. The staining intensity and number of epidermal melanocytes increased in melasma lesions. Lesional skin showed more prominent solar elastosis compared with normal skin. Melanosomes increased in number and were more widely dispersed in the keratinocytes of the lesional skin. Lesional melanocytes had many more mitochondria, Golgi apparatus, rough endoplasmic reticulum and ribosomes in their cytoplasm. A dihydroxyphenylalanine reaction was apparent in the cisternae and vesicles of the trans-Golgi network in melanocytes from lesional skin. CONCLUSIONS: Melasma is characterized by epidermal hyperpigmentation, possibly caused both by an increased number of melanocytes and by an increased activity of melanogenic enzymes overlying dermal changes caused by solar radiation.

Adult↗

Tissue engineered tracheal prosthesis with acceleratedly cultured homologous chondrocytes as an alternative of tracheal reconstruction.

BACKGROUND: Autologous tissue is an ideal substitue for an extensive tracheal reconstruction, but it is rarely feasible in clinical situations. Many tracheal prosthesis had been used for such an instances, but unfortunately it is still problematic. Dislocation, local infection, hemorrage, and luminal stenosis can cause prosthetic failure. To achieve clinically available autologous tracheal prosthesis, it is necessary that we have to get phenotypically functioning chondrocytes, rapid differentiation of harvested autologous chondrocytes, and the survival of free grafted cultured chondrocytes. METHODS: In this study, we investigated isolation and culture method of the chondrocytes using the rabbit costal cartilage, and the cells were characterized microscopically and biochemically first. Then we have used cultured rabbit chondrocytes to investigate the role of growth factors upon the proliferation and regulation of the cultured chondrocytes. We have examined the effect of peptide growth factors on DNA and proteoglycan synthesis to the rabbit chondrocyte. The effects of IGF-I and basic FGF were investigated individually. Secondly, acceleratedly cultured chondrocytes were embeded to polymer (PLGA) scaffold in bioreactor, and implanted to defected rabbit trachea. Six weeks later, the rabbits were sacrificed and examined their histologic characteristics. RESULTS: The harvested chondrocytes from costal arch grew well and were amplified successfully maitaining their own phenotypes. Its embedding to PLGA scaffold was accomplished successfully. The implanted tracheal prosthesis maintains its physical integrity well, but the histologic examination revealed non-viable chondrocytes. The epithelial linings were good. CONCLUSIONS: The tissue engineered tracheal prosthesis can be a promising alternative of good functional air way tube in short term experiment, but biologically not vital yet. Further investigations are necessary to see the survival of free grafted chondrocytes and the long term results.

Animals↗

Measurement of the branching ratios of D(+) and D(+)(s) hadronic decays to four-body final states containing a K(S).

We have studied hadronic four-body decays of D(+) and D(+)(s) mesons with a K(S) in the final state using data recorded during the 1996-1997 fixed-target run of the Fermilab high energy photoproduction experiment FOCUS. We report a new branching ratio measurement of gamma(D(+)-->K(S)K-pi(+)pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0768+/-0.0041+/-0.0032. We make the first observation of three new decay modes with branching ratios gamma(D(+)-->K(S)K+pi(+)pi(-))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0562+/-0.0039+/-0.0040, gamma(D(+)-->K(S)K+K-pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0077+/-0.0015+/-0.0009, and gamma(D(+)(s)-->K(S)K+pi(+)pi(-))/gamma(D(+)(s)-->K(S)K-pi(+)pi(+)) = 0.586+/-0.052+/-0.043, where in each case the first error is statistical and the second error is systematic.

Journal Article↗

Solar 8B and hep neutrino measurements from 1258 days of Super-Kamiokande data.

Solar neutrino measurements from 1258 days of data from the Super-Kamiokande detector are presented. The measurements are based on recoil electrons in the energy range 5.0-20.0 MeV. The measured solar neutrino flux is 2.32+/-0.03(stat)+0.08-0.07(syst)x10(6) cm(-2) x s(-1), which is 45.1+/-0.5(stat)+1.6-1.4(syst)% of that predicted by the BP2000 SSM. The day vs night flux asymmetry (Phi(n)-Phi(d))/Phi(average) is 0.033+/-0.022(stat)+0.013-0.012(syst). The recoil electron energy spectrum is consistent with no spectral distortion. For the hep neutrino flux, we set a 90% C.L. upper limit of 40x10(3) cm(-2) x s(-1), which is 4.3 times the BP2000 SSM prediction.

Journal Article↗