Pulmonary renal syndrome and thrombotic thrombocytopenic purpura in a patient with giant cavernous hemangioma of the leg.
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Biomedical subjects
Publications and source records attributed to K W Chan.
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We report a 6-year-old boy with an intermediate form of fucosidosis.
Seizure is a recognized complication of high-dose busulfan (BU) therapy and phenytoin (DPH) is widely used as prophylaxis. A number of adverse effects have been associated with DPH and it may also interfere with BU metabolism. We used lorazepam (median dose 0.022 mg/kg) i.v. or p.o. before each dose and for 24 h after the last dose of BU as seizure prophylaxis to 29 children undergoing hematopoietic stem cell transplantation. The regimen was well tolerated and drowsiness was the only significant side-effect. Twelve patients were able to receive the entire prophylaxis by mouth. No seizure developed during and within 48 h of BU. Concomitant pharmacokinetic studies showed no alternation of the absorption and clearance of BU during lorazepam administration. Lorazepam can be used as an alternative for seizure prophylaxis during high-dose BU treatment.
BACKGROUND/PURPOSE: The pathogenesis of necrotizing enterocolitis (NEC) is unknown. Ischemia and reperfusion (I/R) injury has been considered a major contributing factor. Nitric oxide (NO) and superoxide dismutases (SODs) have been shown to protect bowel from I/R injury. This study aims to assess (1) the ability of premature intestine to resist I/R injury compared with mature intestine and (2) the possible role of NO and SODs in modulating such response. METHODS: Intestines from 5 groups of rats (n = 6 for each study group) were studied: (1) premature, gestational age 20 days; (2) premature, gestational age 22 days; (3) full-term, newborn; (4) infant, day 15; (5) infant, day 30. EXPERIMENTS: (1) The degrees of I/R injury after 0, 30, 60, 90 and 120 minutes, respectively, of ischemia and 25 minutes of I/R were assessed histologically by a pathologist who was unaware of the operative details. (2) Tissue NO and copper levels were measured by electroparamagnetic resonance (EPR) study; and nitric oxide synthases, copper zinc (CuZn) SODs and manganese (Mn) SODs were examined immunohistochemically. (3) and (4) I/R injury was assessed in rats that had received intraperitoneal injections of L-arginine (NO donor) and L-NAME (NO antagonist), respectively. RESULTS: For premature (1,2), newborn (3) and mature (4,5) intestines, grades of injury at maximum I/R period studied (120 minutes of ischemia, 25 minutes of reperfusion) were 0, 0, and 3, respectively (P <.05); NO levels were 1 u +/- 1.5, 3 +/- 2.5, and 22 u +/- 3.5, respectively (P <.05); Cu levels were 150 u +/- 15, 200 u +/- 41 and 12 u +/- 2, respectively (P <.05); NOS in intestines were +, +, +++ and CuZnSODs were ++, +++, +, respectively; and MnSODs were +++, ++, -, respectively. No change in NO levels was detected in groups (1), (2), or (3) after L-arginine and L-NAME injections. CONCLUSIONS: Premature rat intestine is highly resistant to I/R injury, which may indicate that I/R alone, in the absence of other predisposing factors (eg, bacterial colonization) may not be sufficient in causing NEC. Nitric oxide does not have a protective role for immature and newborn intestines in I/R as in mature intestine. The high level of SODs of the immature and newborn intestine may play an important role in its high resistance to I/R injury.
PURPOSE: Immature gut immunity can be a predisposing factor for necrotizing enterocolitis (NEC). The gut active immunity and innate defense to the Escherichia coli endotoxin lipopolysaccharide (LPS) in immature and mature rats were studied. METHODS: LPS, started at a dose of 10 mg/kg, was instilled into the stomachs of fetal, newborn, 1-month and 3-month-old rats. Boost doses and normal saline control instillations were given on day 14. Rats that died after instillation had detailed postmortem examinations. For survivors, a group of 6 immunized and 6 controls were killed on day 7 for the collection of serum, spleens, mesenteric lymph nodes, and small intestines. Lymphocytes (10(6)) prepared from each tissue sample of individual group were cultured for 5 days. Serum and supernatant were analyzed for IgA and anti-E coli IgA levels. RESULTS: All control rats survived. The doses of LPS given were 10, 5, 2.5, and 1.25 mg/kg. All fetal rats died after LPS instillation. Half-lethal dose for newborns was 2.5 mg/kg. One-month and 3-month-old rats survived all doses of LPS. The cause of death was endotoxemia. The serum IgA and total supernatant anti- E coli IgA levels of rats of all ages studied showed no significant difference. CONCLUSION: The poor innate gut defense, not so much the active immunity, may provide an explanation for the susceptibility of the premature babies and newborn infants to the development of NEC.
BACKGROUND AND STUDY AIMS: As a bowel cleansing agent for colonoscopy, sodium phosphate (NaP) has been reported to have equal effectiveness and better patient tolerance in comparison with 4 l polyethylene glycol-electrolyte lavage (PEG-EL) solution. Poor patient tolerance is frequently associated with a large amount of fluid consumed, and better patient tolerance might therefore be expected if the volume of PEG-EL solution could be reduced. This study aimed to compare 2 l PEG-EL solution with NaP in relation to patients' tolerance and its effectiveness as a bowel cleansing agent. PATIENTS AND METHODS: Two hundred consecutive patients admitted to the day-procedure ward for elective colonoscopy were prospectively randomized to receive either a 2-l PEG-EL solution or a 90-ml oral NaP regimen. Patients with a history of congestive heart failure, impaired renal function (creatinine > 1.5 mg/dl), or previous colectomy were excluded from the study. The patients completed a questionnaire to assess their tolerance of bowel preparation before the colonoscopy. Endoscopists, who were blinded to the type of regimen that had been used, scored the adequacy of bowel preparation from the rectum to cecum using a defined endoscopic score. RESULTS: Two hundred patients were included in this randomized trial. Nine patients were excluded, due to either an incomplete questionnaire (two in the PEG-EL group, one in the NaP group) or inability to complete the bowel preparation regimen (four in the PEG-EL group and two in the NaP group). The demographic data were comparable in the two groups. There were no differences between the two groups with regard to willingness to repeat the regimen, ease of consumption, acceptability of the bowel preparation regimen, or the endoscopists' satisfaction with the quality of bowel preparation. The NaP group had a better mean endoscopic score at the cecum compared with the PEG-EL group (1.47 +/- 1.15 vs. 1.05 +/- 0.76; P = 0.007). CONCLUSIONS: The effectiveness and patient tolerance of the 2-l PEG-EL solution is comparable with that of oral NaP. The 2-l PEG-EL solution is therefore an effective alternative as a bowel-cleansing agent for colonoscopy.
Mycophenolate mofetil (MMF), an immunosuppressive drug commonly used in organ transplantation, is increasingly being used to treat autoimmune diseases including systemic lupus erythematosus (SLE). Excessive production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) has been implicated in the pathogenesis of lupus nephritis. We evaluated the effect of MMF on the severity of nephritis and the production of NO in lupus-prone MRL/lpr mice. Eight-week-old female MRL/lpr mice (n = 20) were treated with MMF (100 mg/kg/day) by oral gavage for 12 weeks. Control mice (n = 20) received vehicle on the same schedule. The mice were killed after 12 weeks of treatment. Treatment with MMF significantly decreased the amount of proteinuria, prolonged survival and reduced the histological severity of glomerulonephritis. Urinary nitrite/nitrate excretion in the MMF-treated mice was significantly reduced during the first 8 weeks of treatment. However, by the end of the 12 weeks' treatment period, there was no significant difference between vehicle and MMF-treated mice in terms of urinary nitrite/nitrate excretion, intra-renal production of NO, expression of iNOS protein and induction of iNOS mRNA. We conclude that MMF is effective in attenuating the severity of nephritis in MRL/lpr mice. The beneficial effects of MMF on lupus nephritis during the early phase of the disease might be partly attributed to the inhibition of NO production. The inhibitory effect of MMF on NO production diminishes as the disease progresses. MMF probably has additional, as yet undefined mode of actions to fully account for its beneficial effects on lupus nephritis.
Diphyllobothriasis is a disease caused by infection with adult tapeworms of the genus Diphyllobothrium. Humans acquire the infection by consuming the raw or inadequately cooked flesh, roe, liver, or other organs of infected fish. Diphyllobothrium latum infection has not been reported in Malaysia; we are reporting the first case. The patient was a 62 year old Chinese male seen at the outpatient clinic with complaints of watery stools and slight abdominal discomfort for four days. Physical examination was normal. He was treated for diarrhea. Two days after treatment, he passed out intact off-white proglottids in his stool. Diphyllobothriasis was confirmed by examination of these gravid proglottids; typical operculated eggs were seen after rupturing the gravid proglottids. The patient had a history of eating sashimi (Japanese raw fish). He was treated with a single dose of praziquantel and had been well since.
Frizzled-related protein (Frp) is a new family of secreted proteins involved in tumorigenesis and Wnt-signaling pathway. Previous study has shown that rat Frp (rFrp) gene was found to be differentially expressed in Rat 6 fibroblast cell line overexpressing p53(val135) (R6#13-8). The rFrp gene was otherwise silent in normal parental Rat 6 cells. To elucidate the molecular basis of the transcriptional activation of rFrp, we have isolated and analyzed a 2-kilobase pair promoter region of the rFrp gene. Mapping of transcription initiation sites of rFrp showed the existence of multiple initiation sites. Transfection studies of serial deletion constructs in both Rat 6 and CHOK1 cell lines revealed that the region from -202 to -144 contains cis-acting elements essential for the efficient transcription of rFrp. This work provides a transcriptional regulation basis for Frp and gives insight into its implication in tumorigenesis.
Purpura is the result of hemorrhage into the skin or mucosal membrane. It may represent a relatively benign condition or herald the presence of a serious underlying disorder. Purpura may be secondary to thrombocytopenia, platelet dysfunction, coagulation factor deficiency or vascular defect. Investigation to confirm a diagnosis or to seek reassurance is important. Frequently, the diagnosis can be established on the basis of a careful history and physical examination, and a few key laboratory tests. Indicated tests include a complete blood cell count with platelet count, a peripheral blood smear, and prothrombin and activated partial thromboplastin times.
Therapeutic efficacy of HBsAg-anti-HBs-recombinant DNA harboring hepatitis B virus (HBV) S gene complex was compared with three other therapeutic vaccine candidates (recombinant HBsAg, HBsAg complexed to anti-HBs antibodies and naked plasmid DNA encoding the HBV S gene). After four injections at 3-week intervals, the most pronounced decrease of serum HBsAg, the highest titer of anti-HBs response, the highest level of interferon-gamma produced by splenocytes and potent cytotoxicity T cell response were observed in the HBsAg-anti HBs-sDNA immunized group. Reduced expression of HBsAg in hepatocytes was also shown. The therapeutic mechanism of HBsAg-anti-HBs-DNA was speculated as modulation of HBsAg presentation via both endogenous and exogenous pathways.
The rapid recovery of hematopoiesis after allogeneic blood stem cell transplantation has been attributed to the quality and quantity of hematopoietic progenitors in the blood stem cell grafts from filgrastim-stimulated donors. To determine whether further stimulation with filgrastim after transplantation would affect hematopoietic recovery, a prospective, randomized, controlled study was performed. Forty-two adult recipients of allogeneic blood stem cells from human leukocyte antigen-matched related donors were randomized to receive 10 microg/kg per day filgrastim subcutaneously from day 1 through neutrophil recovery or no growth factor support after transplantation. There was no significant difference between the 2 groups in the number of CD34(+) cells infused (median, 4.8 vs 4.3 x 10(6)/kg). Graft-versus-host (GVHD) disease prophylaxis consisted of tacrolimus and steroids for 9 patients and tacrolimus and minimethotrexate for 33 patients. The group receiving filgrastim had a shorter time to neutrophil levels greater than 0.5 x 10(9)/L (day 12 vs day 15, P =.002) and to neutrophil levels greater than 1.0 x 10(9)/L (day 12 vs day 16, P =.01). The filgrastim group also had a trend for earlier discharge (day 16 vs 20, P =.05). There was no significant difference between the groups in time to platelet recovery, number of transfusions, regimen-related toxicity, infection, incidence of GVHD, relapse, survival, or hospital charges. It can be concluded that the administration of filgrastim after allogeneic blood stem cell transplantation shortens the time to neutrophil recovery. (Blood. 2001;97:3405-3410)
PURPOSE: To determine whether consolidation therapy with high-dose melphalan, etoposide, and total-body irradiation (TBI) with autologous stem-cell support would improve the prognosis for patients with newly diagnosed metastatic Ewing's sarcoma (ES). PATIENTS AND METHODS: Thirty-two eligible patients with newly diagnosed ES metastatic to bone and/or bone marrow were enrolled onto this study. Treatment was initially comprised of five cycles of induction chemotherapy (cyclophosphamide, doxorubicin, and vincristine alternating with ifosfamide and etoposide) and local control. Peripheral-blood stem-cell collection was performed after the second cycle of chemotherapy, with delay if the bone marrow was persistently involved. If patients had a good response to initial therapy, they proceeded to consolidation therapy with melphalan, etoposide, TBI, and stem-cell support. RESULTS: Of the 32 eligible patients, 23 proceeded to high-dose therapy consolidation. Of the nine patients who did not proceed to consolidation, four were secondary to progressive disease and two were secondary to toxicity. Three patients died from toxicity during the high-dose phase of the therapy. The majority of the patients who underwent high-dose consolidation therapy experienced relapse and died with progressive disease. Two-year event-free survival (EFS) for all eligible patients is 20%. The 2-year post-stem-cell reconstitution EFS for the subset of 23 patients who received consolidation therapy is 24%. Analysis of peripheral-blood stem-cell collections by molecular techniques for minimal residual disease showed contamination of at least some samples by tumor cells in all three patients with available data. CONCLUSION: Consolidation with high-dose melphalan, etoposide, TBI, and autologous stem-cell support failed to improve the probability of EFS in this cohort of patients with newly diagnosed metastatic ES.
In order to compare the outcomes of unrelated umbilical cord blood transplants (UCBTs) or bone marrow transplants, 541 children with acute leukemia (AL) transplanted with umbilical cord blood (n = 99), T-cell-depleted unrelated bone marrow transplants (T-UBMT) (n = 180), or nonmanipulated (UBMT) (n = 262), were analyzed in a retrospective multicenter study. Comparisons were performed after adjustment for patient, disease, and transplant variables. The major difference between the 3 groups was the higher number in the UCBT group of HLA mismatches (defined by serology for class I and molecular typing for DRB1). The donor was HLA mismatched in 92% of UCBTs, in 18% of UBMTs, and in 43% of T-UBMTs (P <.001). Other significant differences were observed in pretransplant disease characteristics, preparative regimens, graft-versus-host disease (GVHD) prophylaxis, and number of cells infused. Nonadjusted estimates of 2-year survival and event-free survival rates were 49% and 43%, respectively, in the UBMT group, 41% and 37% in the T-UBMT group, and 35% and 31% in the UCBT group. After adjustment, differences in outcomes appeared in the first 100 days after the transplantation. Compared with UBMT recipients, UCBT recipients had delayed hematopoietic recovery (Hazard ratio [HR] = 0.37; 95% confidence interval [95CI]: 0.27-0.52; P <.001), increased 100 day transplant-related mortality (HR = 2.13; 95CI: 1.20-3.76; P <.01) and decreased acute graft-versus-host disease (aGVHD) (HR = 0.50; 95CI: 0.34-0.73; P <.001). T-UBMT recipients had decreased aGVHD (HR = 0.25; 95CI: 0.17-0.36; P <.0001) and increased risk of relapse (HR = 1.96; 95CI: 1.11-3.45; P =.02). After day 100 posttransplant, the 3 groups achieved similar results in terms of relapse. Chronic GVHD was decreased after T-UBMT (HR = 0.21; 95CI: 0.11-0.37; P <.0001) and UCBT (HR = 0.24; 95CI: 0.01-0.66; P =.002), and overall mortality was higher in T-UBMT recipients (HR = 1.39; 95CI: 0.97-1.99; P <.07). In conclusion, the use of UCBT, as a source of hematopoietic stem cells, is a reasonable option for children with AL lacking an acceptably matched unrelated marrow donor.
Peripheral gammadelta T cells derived from healthy donors were found to exhibit cytotoxicity against a variety of tumor cell lines in vitro, including CNE2, which was established from nasopharyngeal carcinoma (NPC). The anti-tumor effects were further studied in a mouse model. Control nude mice inoculated s.c. with 5 x 10(6) CNE2 cells regularly developed hypodermal tumors, which progressively increased in size, and animals had a mean survival of 35 +/- 3.4 days. Tumor growth was arrested and tumor size was reduced after animals were infused with 5 x 10(7) gammadelta T cells derived from a healthy donor. The anti-tumor effects were temporary, however, and tumor growth was resumed after about 1 week in a group of the animals that had been given a single dose of gammadelta T cells. In another group of animals given 2 doses of gammadelta cells 1 week apart, resumption of tumor growth was delayed for a further week. Mean survival of the 2 groups was increased to 61 +/- 15.7 and 74 +/- 12.9 days, respectively. Immunohistology revealed an accumulation of infused cells in tumors attended by focal tumor necrosis in specimens taken 2 days after infusion. Infiltrative cells virtually disappeared from tumor tissues 6 days after infusion, accompanied by increased mitotic indices of tumor cells. These temporal relationships suggested that the accumulation of infused gammadelta T cells in hypodermal tumors was responsible for the observed anti-tumor effects.
A LC-LC/MS/MS method has been developed that significantly increases the throughput in metabolism screening of drug candidates during lead optimization in discovery. This was accomplished by the reduction of sample preparation time through an on-line extraction of a drug and its metabolites from microsomal proteins using turbulent flow chromatography. Following its injection onto a column at turbulent flow, the drug and its metabolites are backwashed onto a reverse-phase column via on-line column switching and resolved chromatographically at a laminar flow of 2 mL/min. This tandem turbulent-laminar flow chromatographic system in a total cycle time of 8 min can achieve adequate separation of isomeric metabolites of venlafaxine, haloperidol, or adatanserin. Further improvement in throughput can be achieved by multiplexing both microsomal stability assessment and metabolite profiling into a single analysis. This is made possible by the ability of the ion-trap mass spectrometer to perform simultaneously multiple-reaction monitoring for microsomal stability and data-dependent multiple-stage mass spectrometric analysis for metabolite profiling within a single LC analysis. Such a LC-LC/MS/MS approach can dramatically shorten the time for providing metabolism feedback to the drug discovery process.