Umbilical cord blood transplantation

Over the past decade umbilical cord blood has been established as a viable source of hematopoietic stem cell for allogeneic transplantation. Early experience with umbilical cord blood transplantation (CBT) demonstrated a lower incidence of graft-versus-host disease even though the procedure was performed with HLA-disparate grafts. The overall outcome of CBT appears similar to that of allogeneic bone marrow transplant. The expansion of the donor selection is particularly beneficial to ethnic minorities, whose representation in the marrow registries is relatively small. The major drawbacks of CBT are slow hematopoietic recovery and a high incidence of graft failure, as a result of a lower number of progenitors infused. This paper reviews the current results of CBT and ongoing investigations to increase its availability to a larger number of recipients.

Glomerular Pathology of Allograft Kidneys in Hong Kong

AIMS

Our goal was to define the spectrum of glomerular diseases in allograft kidneys and to correlate them with clinical parameters.

METHODS

Eight hundred ninety-one renal graft biopsies and 43 graft nephrectomies from 1980 to 2004 were obtained from 442 allografts transplanted to 425 patients.

RESULTS

Glomerular diseases were diagnosed in 33% of kidney grafts. Indications for biopsy were baseline assessment (23 biopsies, 2.5%); renal dysfunction (790 biopsies, 88.7%); proteinuria (154 biopsies, 17.3%); hematuria (11 biopsies, 1.2%); and study protocol (four biopsies, 0.4%). The median time to take a biopsy was less than 8 months posttransplant. The mean time posttransplant when the biopsy diagnosis was made was 70 months for IgA nephropathy (IgAN); 66 months for transplant glomerulopathy (TG); 65 months for focal segmental glomerulosclerosis (FSG); 55 months for mesangiocapillary glomerulonephritis (MCGN); 45 months for membranous glomerulonephritis (GN); 49 months for mesangial proliferative GN; and 101 months for diabetic nephropathy. Recurrent glomerular disease was documented in 31 (7.0%) grafts. Specific glomerular diseases were diagnosed by biopsies in 106 (89.1%) of 119 proteinuric allografts.

CONCLUSIONS

Glomerulopathy was common in allografted kidneys. IgAN, TG, FSG, mesangial proliferative GN, and membranous GN were the majority. A higher proportion of grafts from donors related to the recipients than from unrelated donors showed IgAN (P < .05), suggesting that genetic factors might play a role in the pathogenesis of IgAN. Recurrence of glomerulopathy underlying ESRD was frequent for IgAN, FSG, and MCGN, but this was rarely seen in membranous GN.

Flow cytometry and fluorescence in situ hybridization to detect residual neuroblastoma cells in bone marrow

BACKGROUND

In patients with neuroblastoma morphological assessment of BM for residual NB cells is not precise, particularly when the number of tumor cells is small.

PROCEDURE

To develop a sensitive and rapid method of detecting NB cells in BM, we assessed the efficiency of flow cytometry (FCM) using markers CD9, CD56, and CD45. The percent of CD9+/CD56+/CD45- (NB phenotype) cells was determined by FCM in 41 samples (16 patients) at various time points. For confirmation fluorescence in situ hybridization (FISH) for 17q gain was performed.

RESULTS

Nineteen of the 22 (86%) samples that were negative by morphology were positive by FCM (>0.006% CD9+/CD56+/CD45- cells). The longest time to complete the FCM study was 3 hr. In six FISH experiments the sorted CD9+/CD56+/CD45- population had a higher percentage of cells with 17q gain (11.5-95%) compared to a CD56-/CD45+ internal control population (2-8%).

CONCLUSIONS

Our preliminary results suggest that FCM determination of the percent of CD9+/CD56+/CD45- cells is an effective method of rapidly detecting NB cells in BM.

Id helix-loop-helix proteins are differentially expressed in gestational trophoblastic disease

AIMS

To assess the expression of Id proteins in trophoblastic tissues and to correlate this with clinical parameters, proliferative and apoptotic indices as well as to related oncogene expression.

METHODS AND RESULTS

Immunohistochemistry for Id1, Id2, Id3 and Id4 was performed on 83 trophoblastic tissues including 17 normal first-trimester placentas, seven term placentas, 47 hydatidiform moles (HM), and 12 spontaneous miscarriages. The four Id proteins were predominantly expressed in the villous and implantation site intermediate trophoblast. Expression of Id1 in HM was significantly higher than that in normal placenta (P = 0.0006) and spontaneous miscarriage (P = 0.0001) but did not correlate with subsequent development of gestational trophoblastic neoplasia (GTN). Id1 expression correlated with the proliferation index as assessed by MCM7 (P = 0.003) and Ki67 (P = 0.017) and with the apoptotic activity assessed by TUNEL (P = 0.001) and M30 CytoDeath antibody (P = 0.013). Moreover, the expression of Id1 correlated with the expression of p53 (P = 0.004), p21(WAF1) (/CIP1) (P = 0.003) but not with p16 (P = 0.107).

CONCLUSIONS

Id proteins may play a role in the regulation of proliferative and apoptotic activity in trophoblastic tissue and are potentially useful in differentiating molar and non-molar gestation, but are not helpful in predicting GTN.

Volar fixation of dorsally displaced distal radial fracture using locking compression plate

PURPOSE

To evaluate the functional and radiological results of treating unstable fractures of the dorsal distal radius with a volar locking plate.

METHODS

Dorsally displaced distal radial fractures in 30 patients (11 men and 19 women; mean age, 58.6 years) were fixed by volar locking compression plate and followed up for a minimum of one year.

RESULTS

At final functional assessment, 24 patients achieved excellent and 5 achieved good outcomes, with one patient exhibiting fair results. Radiological scores demonstrated 22 excellent and 8 good outcomes. No nonunion or infection occurred.

CONCLUSION

Volar locking compression plating is a safe and effective treatment for unstable fractures of the dorsal distal radius.

Primary immunodeficiency in Hong Kong and the use of genetic analysis for diagnosis

OBJECTIVES

To review the management of primary immunodeficiency and discuss recent advances in genetic analysis.

DESIGN

Retrospective study.

SETTING

University teaching hospital, Hong Kong.

PATIENTS

Children diagnosed with primary immunodeficiency and followed up in the immunology clinic during the period 1988 to 2003.

MAIN OUTCOME MEASURES

Demographic data, co-morbidities and treatment of patients, outcome and complications; identification of disease by genetic mutations.

RESULTS

Medical records of a total of 117 patients (72 male, 45 female) diagnosed with primary immunodeficiency in the Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Hong Kong during the past 15 years (1988-2003) were reviewed. All patients were followed up in the immunology clinic. Some patients had been referred from the private sector or other hospitals for immunological workup. Six categories of primary immunodeficiency were identified: predominantly humoral defect (n=50), predominantly cellular defect (n=22), combined humoral and cellular defect (n=5), phagocytic defect (n=18), complement disorders (n=4), and others (n=18). Although infection was the underlying cause of most co-morbidities and mortality, autoimmune (n=7) and allergic (n=23) manifestations were common. In addition, three patients developed lymphoma. Recent advances in the genetic diagnosis of several types of primary immunodeficiency were also reviewed: X-linked Wiskott-Aldrich syndrome, X-linked chronic granulomatous disease, X-linked agammaglobulinaemia, X-linked lymphoproliferative syndrome, leukocyte adhesion disease type I, and X-linked hyperimmunoglobulin M syndrome. This provides an invaluable means of understanding the molecular basis of primary immunodeficiency and has important clinical applications.

CONCLUSIONS

Co-morbidities like autoimmune disease and allergic disease are common in patients with primary immunodeficiency and should be carefully evaluated. Likewise, a diagnosis of primary immunodeficiency should be considered when evaluating patients with these conditions. Rapid progress in the field of molecular genetics will enable definite and early diagnosis, and more importantly, potential curative therapy to be administered.

Safety and efficacy of allogeneic PBSC collection in normal pediatric donors: The Pediatric Blood and Marrow Transplant Consortium Experience (PBMTC) 1996–2003

The use of peripheral blood stem cells (PBSC) for allogeneic transplants in adults has greatly increased. This trend is reflected in pediatrics, where healthy children increasingly are donating PBSC or donor lymphocyte infusion (DLI) via apheresis for use by ill siblings. There is a potential concern that the risks of PBSC collection may differ for pediatric donors. However, no large studies have assessed safety issues in this population. To address this need, we reviewed 218 (213 PBSC, five DLI) collections in 201 normal pediatric donors (8 months to 17 years, median 11.8 years) at 22 institutions in the Pediatric Blood and Marrow Transplant Consortium. Donors received a median of 4 days of growth factor, and mean collection yield was 9.1 x 10(6) CD34+ cells/kg recipient weight. Younger age, days of apheresis, and male gender predicted increased yield of CD34+ cells/kg donor weight. Growth factor-induced pain was mild and reported in less than 15% of patients. Most donors <20 kg (23/25, 92%) required PRBC priming of the apheresis machine. This experience with over 200 collections demonstrates that PBSC collection is safe in normal pediatric donors and desired CD34 cell yields are easily achieved. Younger children utilize more medical resources and children <20 kg usually require a single blood product exposure.

Pharmacokinetics and individualized dose adjustment of intravenous busulfan in children with advanced hematologic malignancies undergoing allogeneic stem cell transplantation

We investigated the pharmacokinetics (PK) of a recently approved intravenous busulfan (IVBU) formulation as a part of the preparative regimen in 20 children with advanced hematologic malignancies undergoing allogeneic hematopoietic stem cell transplantation. Seventeen patients received a thiotepa, IVBU, and cyclophosphamide-based regimen, and 3 patients received an IVBU and cyclophosphamide-based regimen. All patients received IVBU 0.8 mg/kg for the first 2 doses; thereafter, the IVBU dose was modified, if required, to achieve a final area under the concentration-time curve (AUC) at steady state of 1150 micromol/L/min per dose (range, 1000-1300 micromol/L/min per dose; SD +/-13%) based on the first-dose PK determination. PK studies were repeated on subsequent doses to verify the final AUC. Initial mean IVBU clearance and half-life were 3.96 mL/min/kg and 1.98 hours, respectively. Sixteen (80%) of the 20 patients received dose adjustments: 14 patients required dose escalations, and 2 required dose reductions. Overall, thirteen (72%) of 18 available sample sets at final follow-up PK analysis showed the IVBU exposure to be within the targeted range. IVBU PK was linear, and interpatient variability was much lower than that observed with oral busulfan. IVBU was well tolerated, and no case of hepatic veno-occlusive disease was encountered. Mild and transient hyperbilirubinemia was observed in 7 patients. Thirteen of the 20 patients were alive at a median follow-up of 651 days (range, 386-1555 days). We conclude that a standardized IVBU dose of 0.8 mg/kg in children does not always result in an AUC within the reference range defined in this study. Therapeutic drug monitoring with dose adjustment based on first-dose PK can optimize the systemic busulfan exposure for children undergoing allogeneic hematopoietic stem cell transplantation.

Low temperature blocks the stimulatory effect of human chorionic gonadotropin on steroidogenic acute regulatory protein mRNA and testosterone production but not cyclic adenosine monophosphate in mouse Leydig tumor cells

Low temperatures slow down metabolism, partly because the kinetic energy of molecules is reduced and enzymes may be structurally impaired. We now report that relative to its maximal activity at 37 degrees C, adenylate cyclase (AC) still retained 25% functionality (determined as cyclic adenosine monophosphate [cAMP] production) at 4 degrees C in mouse Leydig tumor cells (MLTC-1) in response to 50 IU/L human chorionic gonadotropin (hCG), whereas steroidogenic acute regulatory (StAR) protein mRNA and testosterone production were completely impaired. The incubation of MLTC-1 with the phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine; IBMX) resulted in significantly increased intracellular cAMP concentration at all 3 temperatures, but this had no impact on testosterone production. AC, cAMP, and phosphodiesterase form an important intracellular second-messenger mechanism in many organisms, some that inhabit very low temperature niches. The cold-resistance of AC and phosphodiesterase may thus have evolved to cope with adverse conditions. Although hibernation may lead to decreased steroid hormone production, it is also likely that cold-mediated decreased steroid hormone production induces hibernation.

Dynamic gadolinium-enhanced magnetic resonance urography for assessing drainage in dilated pelvicalyceal systems with moderate renal function: preliminary results and comparison with diuresis renography

OBJECTIVE

To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function.

PATIENTS AND METHODS

Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies.

RESULTS

Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23).

CONCLUSION

These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.

The use of a distal occlusion balloon protection device in acute coronary syndrome

We report our early experience in using the PercuSurge GuardWire Plus system as a distal protection device in patients with acute coronary syndrome and acute myocardial infarction. Forty-three patients received percutaneous coronary intervention with the GuardWire Plus system. Thirteen had unstable angina, five had non-Q myocardial infarction and 25 had ST segment elevation myocardial infarction. Forty-one target lesions were in native coronary vessels and two were in saphenous vein grafts. Total occlusion occurred in 18 patients. The mean occlusion time by the distal protective balloon was 262.8 +/- 114.1 s. Preoperatively, TIMI 0 flow was present in 18, TIMI II flow in two and TIMI III flow in 23 patients. Post-operatively, TIMI II and TIMI III flow were established in two and 41 patients, respectively. All procedures were successful and the GuardWire Plus system was successfully deployed in all but two patients. There was no procedure-related major adverse clinical event. There was no major adverse clinical event at 30 days. There was no device-related complication. We believe that the GuardWire Plus system is safe and feasible in patients with acute coronary syndrome and acute myocardial infarction.

Consensus statement on iodine deficiency disorders in Hong Kong

This article reviews the available data on the study of iodine deficiency disorders in Hong Kong and to discuss the approach towards preventing such disorders in Hong Kong. The importance of iodine and iodine deficiency disorders is described, and the available data on the dietary iodine intake and urinary iodine concentration in different populations of Hong Kong are summarised and discussed. Dietary iodine insufficiency among pregnant women in Hong Kong is associated with maternal goitrogenesis and hypothyroxinaemia as well as neonatal hypothyroidism. Borderline iodine deficiency exists in the expectant mothers in Hong Kong. Women of reproductive age, and pregnant and lactating women should be made aware and educated to have an adequate iodine intake, such as iodised salt, as an interim measure. A steering group involving all stakeholders should be formed to advise on the strategy of ensuring adequate iodine intake, including universal iodisation of salt in Hong Kong. Continuous surveillance of iodine status in the Hong Kong population is necessary.

Isolation and characterization of viruses related to the SARS coronavirus from animals in southern China

A novel coronavirus (SCoV) is the etiological agent of severe acute respiratory syndrome (SARS). SCoV-like viruses were isolated from Himalayan palm civets found in a live-animal market in Guangdong, China. Evidence of virus infection was also detected in other animals (including a raccoon dog, Nyctereutes procyonoides) and in humans working at the same market. All the animal isolates retain a 29-nucleotide sequence that is not found in most human isolates. The detection of SCoV-like viruses in small, live wild mammals in a retail market indicates a route of interspecies transmission, although the natural reservoir is not known.

Clofarabine, a novel nucleoside analog, is active in pediatric patients with advanced leukemia

Despite progress in leukemia therapy, most children who experience relapse have a dismal prognosis. New, effective approaches are needed. We conducted a phase 1 study of a novel nucleoside analog, clofarabine, in pediatric patients with refractory and relapsed leukemia. Clofarabine was infused intravenously over 1 hour each day for 5 days. Six dose levels, between 11.25 and 70 mg/m(2) per day for 5 days, were studied in 25 patients. A modified 3 + 3 phase 1 design was followed with 30% dose escalation until the dose-limiting toxicity (DLT) was defined. The maximum tolerated dose (MTD) was 52 mg/m(2) per day for 5 days. At the end of infusion at MTD, clofarabine triphosphate levels in leukemia blasts varied between 6 microM and 19 microM, which resulted in complete and sustained inhibition of DNA synthesis. The DLT was reversible hepatotoxicity and skin rash at 70 mg/m(2) per day for 5 days. Twenty-five patients were treated. Five patients achieved complete remission (CR), and 3 achieved partial remission (PR), for an overall response rate of 32%. Clofarabine is well tolerated and shows significant antileukemic activity in heavily pretreated children. Multicenter phase 2 trials in pediatric acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) are ongoing.

Two-port versus four-port laparoscopic cholecystectomy

BACKGROUND

Two-port laparoscopic cholecystectomy has been reported to be safe and feasible. However, whether it offers any additional advantages remains controversial. This study reports a randomized trial that compared the clinical outcomes of two-port laparoscopic cholecystectomy versus conventional four-port laparoscopic cholecystectomy.

METHODS

One hundred and twenty consecutive patients who underwent elective laparoscopic cholecystectomy were randomized to receive either the two-port or the four-port technique. All patients were blinded to the type of operation they underwent. Four surgical tapes were applied to standard four-port sites in both groups at the end of the operation. All dressings were kept intact until the first follow-up 1 week after surgery. Postoperative pain at the four sites was assessed on the first day after surgery using a 10-cm unscaled visual analog scale (VAS). Other outcome measures included analgesia requirements, length and difficulty of the operation, postoperative stay, and patient satisfaction score on surgery and scars.

RESULTS

Demographic data were comparable for both groups. Patients in the two-port group had shorter mean operative time (54.6 +/- 24.7 min vs 66.9 +/- 33.1 min for the four-post group; p = 0.03) and less pain at individual subcostal port sites [mean score using 10-cm unscaled VAS: 1.5 vs 2.8 ( p = 0.01) at the midsubcostal port site and 1.3 vs 2.3 ( p = 0.02) at the lateral subcostal port site]. Overall pain score, analgesia requirements, hospital stay, and patient satisfaction score on surgery and scars were similar between the two groups.

CONCLUSION

Two-port laparoscopic cholecystectomy resulted in less individual port-site pain and similar clinical outcomes but fewer surgical scars compared to four-port laparoscopic cholecystectomy. Thus, it can be recommended as a routine procedure in elective laparoscopic cholecystectomy.