Development of a Novel Quinoline Derivative as a P-Glycoprotein Inhibitor to Reverse Multidrug Resistance in Cancer Cells

Multidrug resistance (MDR) is one of conventional cancer chemotherapy’s limitations. Our group previously synthesized a series of quinoline-based compounds in an attempt to identify novel anticancer agents. With a molecular docking analysis, the novel compound 160a was predicted to target p-glycoprotein, an MDR candidate. The purpose of this study is to evaluate 160a’s MDR reversal effect and investigate the underlying mechanism at the molecular level. To investigate 160a’s inhibitory effect, we used a series of parental cancer cell lines (A549, LCC6, KYSE150, and MCF-7), the corresponding doxorubicin-resistant cell lines, an MTS cytotoxicity assay, an intracellular doxorubicin accumulation test, and multidrug resistance assays. The Compusyn program confirmed, with a combination index (CI) value greater than 1, that 160a combined with doxorubicin exerts a synergistic effect. Intracellular doxorubicin accumulation and transported calcein acetoxymethyl (AM) (a substrate for p-glycoprotein) were both increased when cancer cells with MDR were treated with compound 160a. We also showed that compound 160a’s MDR reversal effect can persist for at least 1 h. Taken together, these results suggest that the quinoline compound 160a possesses high potential to reverse MDR by inhibiting p-glycoprotein-mediated drug efflux in cancer cells with MDR.

Recent advances on topical antimicrobials for skin and soft tissue infections and their safety concerns

Antimicrobial resistance of disease-related microorganisms is considered a worldwide prevalent and serious issue which increases the failure of treatment outcomes and leads to high mortality. Considering that the increased resistance to systemic antimicrobial therapy often needs of the use of more toxic agents, topical antimicrobial therapy emerges as an attractive route for the treatment of infectious diseases. The topical antimicrobial therapy is based on the absorption of high drug doses in a readily accessible skin surface, resulting in a reduction of microbial proliferation at infected skin sites. Topical antimicrobials retain the following features: (a) they are able to escape the enzymatic degradation and rapid clearance in the gastrointestinal tract or the first-pass metabolism during oral administration; (b) alleviate the physical discomfort related to intravenous injection; (c) reduce possible adverse effects and drug interactions of systemic administrations; (d) increase patient compliance and convenience; and (e) reduce the treatment costs. Novel antimicrobials for topical application have been widely exploited to control the emergence of drug-resistant microorganisms. This review provides a description of antimicrobial resistance, common microorganisms causing skin and soft tissue infections, topical delivery route of antimicrobials, safety concerns of topical antimicrobials, recent advances, challenges and future prospective in topical antimicrobial development.

Luminous fabric devices for wearable low-level light therapy

In this paper, a flexible luminous fabric device was developed and investigated for wearable three-dimensionally fitted low-level light therapy. The fabric device exhibited excellent optical and thermal properties. Its optical power density and operating temperature were stable during usage for 10 hours. In vitro experiments demonstrated a significant increase in collagen production in human fibroblast irradiated by the fabric device, compared with the fibroblast without light irradiation. A series of tests were conducted for the safety of the fabric for human skin contact according to ISO standard ISO 10993-1:2003. The results showed that there was no potential hazard when the luminous fabrics were in direct contact with human skin.

Comparing histopathological classification with MYCN, 1p36 and 17q status detected by fluorescence in situ hybridisation from 14 untreated primary neuroblastomas in Singapore

INTRODUCTION

Neuroblastoma is the most common extracranial solid tumour in children, accounting for about 5.3 percent of all childhood cancers in Singapore. Several genetic abnormalities have been reported as prognostic markers, including amplification of the MYCN gene, deletion of the short arm of chromosome 1 (1p) and gain of the long arm of chromosome 17 (17q). However, the correlation between tumour histology and these genetic parameters remains to be established in our local population.

METHODS

14 untreated primary neuroblastoma tumours, diagnosed consecutively in our hospital between 2003 and 2007, were included for this study. Tumour tissues were classified histologically as favourable or unfavourable, according to the modification of World Heath Organization Classification of Tumours, by associating the degree of differentiation and mitotic-karyorrhectic index of the neuroblastoma to the age of the patient. Fluorescence in situ hybridisation analysis for MYCN, 1p status and 17q status were subsequently performed on tumour touch imprints.

RESULTS

Five tumours with favourable histology were all negative for the three genetic parameters being investigated. The other nine tumours showing unfavourable histology exhibited one or more of the three genetic parameters. All MYCN amplified tumours either had additional 1p deletion and/or 17q gain.

CONCLUSION

Our limited data suggests that 1p deletion and 17q gain are reliable independent parameters correlating with an unfavourable histology and poor clinical outcome. The use of 1p deletion and 17q gain studies, in addition to MYCN amplification studies, should be considered routinely in predicting prognosis in neuroblastomas.

Antibiotics and postoperative abscesses in complicated appendicitis: is there any association?

INTRODUCTION

Complicated appendicitis has significant infective postoperative morbidity. There is no universally-accepted antibiotic regime, although traditionally, triple antibiotics are recommended. Our complicated appendicitis clinical pathway recommends ceftriaxone and metronidazole. The study aimed to determine if choice of antibiotics influenced the risk of infective complications.

METHODS

We reviewed all paediatric appendicectomy patients between January 1, 2005 and December 31, 2005. All patients with intraoperative diagnosis of perforated appendicitis were recruited, excluding infants, immunocompromised patients, and patients allergic to the guideline antibiotics. All operations were performed by registrar/consultant surgeons and were laparoscopic, unless technically not feasible.

RESULTS

There were 82 patients with perforated appendicitis. 62 patients (76 percent) followed pathway antibiotics, and 20 patients (24 percent) deviated from the pathway by receiving additional empiric gentamycin. We compared the pathway compliant and deviation groups, and found no significant differences in patient characteristics, clinical presentation, operation, length of stay and infective complications. Overall there was one wound infection and five (six percent) postoperative abscesses. Initial peritoneal cultures and subsequent drainage cultures of patients who developed abscesses were sensitive to treatment antibiotics.

CONCLUSION

In complicated appendicitis, empirical perioperative addition of gentamycin to ceftriaxone and metronidazole did not reduce the risk of developing intra-abdominal abscess, compared to changing antibiotics on clinical grounds. Patients developed postoperative abscesses despite initial peritoneal cultures growing organisms sensitive to treatment antibiotics.

Cervical ectopic thymus in an infant

Cervical ectopic thymus, a common embryological anomaly detected incidentally at autopsy, is rarely described in clinical patients. About 100 cases have been described in the literature, ten percent of which occurred in neonates. We report a case of solid cervical ectopic thymus in a three-month-old male infant presenting as a neck lump and snoring at sleep. The embryopathogenesis, clinical features, diagnostic modalities and management options are discussed, together with a review of the literature.

Fetus-in-fetu in the pelvis: report of a case and literature review

INTRODUCTION

Fetus-in-fetu is an extremely rare condition in which a malformed fetus is found in the body of its twin. To our knowledge, fewer than 100 cases have been reported. Wide variations of presentation have been described, although its embryo-pathogenesis and differentiation from a teratoma have not been well established.

CLINICAL PICTURE

We describe a male neonate with a fetoid-like mass in his pelvis associated with bilateral undescended testes. The mass was detected on prenatal ultrasound scans. The diagnosis of fetus-in-fetu was considered prenatally and confirmed on a computed tomography scan after birth.

OUTCOME

The mass was successfully excised. Histological examination, accompanied by a review of the literature, confirmed that the mass had features consistent with a fetus-in-fetu.

CONCLUSIONS

Although an extremely rare clinical entity, fetus-in-fetu can be diagnosed prior to surgery with current imaging modalities. When it arises in the retroperitoneum of a male infant, it can hinder the descent of the testes. Complete excision is curative.

When is a mediastinal mass critical in a child? An analysis of 29 patients

The aims of this study were to determine the pattern of presentation of childhood mediastinal masses in our community and to identify factors associated with the development of acute airway compromise. The authors retrospectively reviewed the records of 29 consecutive patients with mediastinal masses managed at their institution between January 1995 and December 2001. Demographic data, mass characteristics, clinical presentation, and surgical procedures were recorded. Seven patients (24.1%) were asymptomatic at presentation. Eight (27.6%) were classified as having acute airway compromise at presentation. Respiratory symptoms and signs were the most common mode of presentation (58.6% and 55.2%, respectively). The most common histological diagnosis was neurogenic mass (37.9%), followed by lymphoma (24.1%). Most masses were located in the superior mediastinum (41.1%). Factors associated with the development of acute airway compromise were (1) anterior location of the mediastinal mass (P=0.019), (2) histological diagnosis of lymphoma (P=0.008), (3) symptoms and signs of superior vena cava syndrome (P=0.015 and 0.003, respectively), (4) radiological evidence of vessel compression or displacement (P=0.015), (5) pericardial effusion (P=0.015), and (6) pleural effusion (P=0.033). Clinical presentation of childhood mediastinal masses is often nonspecific or incidental. Yet they have the propensity of developing acute airway compromise, which is closely associated with superior vena cava obstruction. Such patients should be managed as a complex cardiorespiratory syndrome, termed "critical mediastinal mass syndrome", by an experienced multidisciplinary team.

Antiproliferative activity of the extract of Gleditsia sinensis fruit on human solid tumour cell lines

BACKGROUND

The fruit extract of Gleditsia sinensis Lam. (GSE) is a traditional herbal medicine that is saponin-rich. However, its activity on solid tumour cell lines has never been demonstrated.

METHODS

The activity of GSE was demonstrated in four cancer cell lines (breast cancer MCF-7, MDA-MB231, hepatoblastoma HepG2 and oesophageal squamous carcinoma cell line SLMT-1) using MTT assay, anchorage-independent clonogenicity assay, DNA laddering and in situ cell death detection.

RESULTS

The mean MTT(50) (the mean concentration of GSE to reduce MTT activity by 50%) ranged from 16 to 20 microg/ml of GSE. An anchorage-independent clonogenicity assay showed that all of the four solid tumour cell lines gradually lost their regeneration potential after treatment with GSE, DNA fragmentation and TUNEL analysis demonstrated that the action of GSE is both dose- and time course-dependent.

CONCLUSIONS

Our results suggest that GSE has a cytotoxic activity and can induce apoptosis in human solid tumour cell lines.

Childhood acute pancreatitis in a children's hospital

OBJECTIVE

To analyse the cases of acute pancreatitis presented to a children's hospital in Singapore.

METHODS

Clinical charts of all children, aged under 18 years, who presented to our hospital for the first time with pancreatitis (ICD search criteria = 577.x) between the period of 1998 and mid-2002 were reviewed. Parameters analysed included presenting features, aetiology of the acute pancreatitis, length of hospital stay, complications, treatment and outcome.

RESULTS

There were 12 cases in the review period, and the attributable causes in these cases were, in descending order, trauma, drug-induced, anatomical anomalies, poisoning and idiopathic. Of interest were two patients whose pancreatitis were results of child abuse. The most common symptoms were abdominal pain (n=11) and vomiting (n=7), though only five patients localised the pain to the epigastrium. Abdominal tenderness could be elicited in all the patients. Eleven had evidence of acute pancreatitis from computerised tomography (CT) whilst the twelfth was diagnosed with ultrasonography. The peak amylase levels amongst these patients were not high, with a median of 512.5 U/L. In the acute stage, only one patient required operative intervention whilst the remainder were managed conservatively. The mean length of hospital stay was 12.41 +/- 4.54 days. The complications encountered included pseudocyst formation, ascites, hypocalcaemia, pleural effusion and coagulopathy.

CONCLUSIONS

The diagnosis of acute pancreatitis in children can be difficult. This is often due to ambiguous symptoms, signs and laboratory results. CT and ultrasound are essential investigations in the diagnosis and subsequent follow-up.

Is reexcision in pediatric nonrhabdomyosarcoma soft tissue sarcoma necessary after an initial unplanned resection?

PURPOSE

The aim of this study was to determine the importance of pretreatment reexcision (PRE) of pediatric nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) after initial unplanned resection.

METHODS

The authors retrospectively reviewed the records of 116 consecutive patients with surgically resected NRSTS treated at their institution between February 1978 and September 1999. Ninety-four (81.0%) patients had undergone unplanned resections before referral to their institution for further therapy. Demographic data, tumor characteristics, treatment administered, and outcomes were recorded.

RESULTS

Sixty-nine patients (73.4%) underwent PRE at a median interval after the initial unplanned resection of 29 days. Twenty-five patients were thought unsuitable for PRE because of the proximity to vital neurovascular bundles. Tumors deemed not feasible for PRE were more likely to be greater than 5 cm (P =.0094) and high grade (P =.0200). Tumor was found in 33 (47.8%) of the PRE specimens, and 24 of these patients (72.7%) were deemed disease free after achieving negative surgical margins. Residual tumor was more likely to be found after PRE in head and neck primary tumors than in trunk wall or extremity primary tumors (P =.0128). There were no local failures in the 60 PRE patients who achieved clear margins. The estimated 5-year event-free and 5-year overall survival rates in these 60 patients were 98.3% +/- 2.0% and 98.2% +/- 2.1%, respectively.

CONCLUSIONS

Pretreatment reexcision should be performed whenever feasible in pediatric patients with NRSTS who had an initial unplanned resection. The proportion of patients with residual tumor in the PRE specimen is high, and negative microscopic margins can be achieved after PRE in most patients with residual tumor. Despite delay in obtaining a complete surgical resection, no local recurrences were seen. The possibility of NRSTS should be considered when resecting a soft tissue mass in children, and diagnostic incisional biopsy followed by wide local excision with negative microscopic margins should be the surgical goal.

Vitamin B12 deficiency--need for a new guideline

OBJECTIVES

Many patients with vitamin B12 deficiency do not have anemia or macrocytosis, but the prevalence of B12 deficiency in patients without macrocytosis is not known.

METHODS

We investigated the prevalence of B12 deficiency among patients with normocytosis and microcytosis and recommended a screening strategy. All patients (n = 3714) with serum B12 measured at the Prince of Wales Hospital in 1996 were reviewed. The prevalence of serum B12 less than 140 pmol/L was determined for the following patient subgroups: younger than 70 y, older than 70 y, anemic, non-anemic, macrocytic, normocytic, microcytic, documented iron deficiency, and documented thalassemia.

RESULTS

The prevalence of B12 deficiency (<140 pmol/L) ranged from 4.8% to 9.8% among the different subgroups.

CONCLUSIONS

Whatever screening criteria were used, a significant number of B12-deficient patients will be missed. Therefore, there may be a case for universal vitamin B12 screening.

Provision of phenotype-matched blood units: no need for pre-transfusion antibody screening

BACKGROUND AND OBJECTIVES

The Hong Kong government is planning to introduce an electronic smart identity card for all seven million citizens in 2003. If the smart card contains the full red cell phenotype/genotype of the individual, it may be possible to transfuse phenotype-matched blood units without pre-transfusion antibody screening. We conducted a feasibility study.

DESIGN AND METHODS

Red cell phenotype was determined for 407 donor blood units and 493 patients for whom an antibody screen had been ordered. The computer program selected phenotype-matched blood from the donor stock for the patients according to actual transfusion request. For patients with a positive antibody screen, full crossmatching was carried out with the computer-selected phenotype units. The frequencies of the various red cell phenotypes in the population were calculated from Red Cross data of antigen frequencies. The probabilities of finding at least one unit of phenotype-matched blood from a 300-unit hospital stock and a 4,000-unit Red Cross stock were determined for each phenotype. Cost analysis was performed.

RESULTS

Ninety-two out of 493 patients received a total of 395 blood units. The required number of phenotype-matched blood units could be found for 92 patients using a 300-unit pool and for all patients using a 4,000-unit pool. We calculated that phenotype-matched blood could be provided for more than 98% of patients without antibody screening. The total cost of the project is US$ 98 million with potential savings of US$ 14 million per year.

INTERPRETATION AND CONCLUSIONS

It is feasible and cost-effective to transfuse patients with phenotype-matched blood without antibody screening using a smart card system.

Successful Engraftment in Two Adult Patients with Severe Aplastic Anemia Using Nonmyeloablative Conditioning Followed by Unrelated HLA-Mismatched Cord Blood Transplantation

Umbilical cord blood as an alternative source of hematopoietic stem cells and nonmyeloablative conditioning are very exciting new developments in transplantation. We report here mixed chimerism in two adult patients with severe aplastic anaemia using nonmyeloablative conditioning and two-antigen mismatched cord blood transplantation resulting in satisfactory clinical response. Our results suggest that such transplant is possible with minimal toxicity.

Transfusion of peripheral blood stem cells from donor homozygous for a shared HLA-haplotype: avoiding fatal transfusion-associated graft-versus-host disease while preserving anti-leukemic effect

BACKGROUND

Fatal transfusion-associated graft-versus-host disease was observed in immunocompetent patients transfused with blood from donors homozygous for a shared haplotype with the recipient (the P-F1 barrier). We tested whether it was possible to carry out successful transplantation in a patient with relapsed acute myeloid leukemia, using peripheral blood stem cells from his HLA-homozygous brother (HLA A2, B46, DRB1 901) who shared a haplotype with the patient (HLA A2, B46,75, DRB1 901,12).

METHODS

A CD34 positively selected cell fraction (5.46x 10(6) CD34 cells/kg) was infused first, followed by subsequent infusion of graded doses of donor T cells (total 7.25x10(7) T cells/kg). Nonmyeloablative chemotherapy with idarubicin and cytarabine was given during the transplantation to reduce the leukemic burden and facilitate engraftment. Polymerase chain reaction with the VNTR primers, D1S80, was used to detect engraftment.

RESULTS

Complete remission (>300days) and successful donor engraftment (90%) were achieved.

CONCLUSIONS

Peripheral blood stem cells transplantation from a donor with a homozygous shared haplotype is possible with a minimal preparative regimen.

Salmonella typhimurium: a rare cause of colonic ulceration and perforation in infancy

A rare case of a healthy infant with colonic ulcers caused by Salmonella typhimurium infection that presented with colonic perforation, hypovolemic, and septicemic shock is discussed. It stresses the importance of considering an infective process such as salmonellosis in the differential diagnosis of colonic ulceration in an infant and illustrates the unique histologic finding of colonic inflammatory changes with sparing of the small intestine.

Cytogenetics and the biologic basis of sarcomas

In this past year, a large number of reports have described cytogenetic and biologic studies of sarcomas. The cytogenetic studies provide further evidence that a growing number of sarcomas seem to be defined by consistent chromosomal abnormalities that can be detected using a variety of molecular genetic tests. However, in addition to these specific abnormalities, many sarcomas have other extremely complex genetic changes. This complexity has made it quite difficult to understand the importance of any single abnormality. Laboratory studies complementing these genetic studies have provided further understanding of sarcoma cellular and molecular biology. Importantly, both types of studies have had significant impact in the clinic in the form of more objective diagnostic tests, potential novel prognostic markers, and even new therapeutic strategies. Together, these papers highlight how genetic studies may offer tremendous insight into sarcoma biology. However, they also highlight some limitations of these approaches as well. Novel experimental approaches may be required to facilitate the continued progress in this field toward the development of better therapeutic strategies.

Improvement in transfusion safety using a specially designed transfusion wristband

Fatal haemolytic transfusion reaction due to ABO incompatibility occurs mainly as a result of clerical error. A blood sample drawn from the wrong patient and labelled as another patient's will not be detected by the blood bank unless there is a previous ABO grouping result. We report here the detection of such clerical error by the use of a specially designed transfusion wristband. The wristband has the following special features: (i) once attached, it cannot be removed except by cutting; (ii) it has a pocket containing a transfusion label; (iii) a unique transfusion barcode is printed on each transfusion label and the corresponding wristband simultaneously by computer technology; (iv) a transfusion label removed from the wristband after attachment to the patient has a characteristic tear-mark distinguishing it from one removed prior to attachment. The blood bank only accepted those specimens bearing the tear-marked transfusion labels. All blood units for this patient were labelled with this unique transfusion code together with the patient's details. The nurses counter-checked the transfusion code on the blood units against the transfusion code on the patient's transfusion wristband prior to transfusion. If the blood sample for compatibility testing was drawn from the 'wrong' patient, the intended patient either did not carry a wristband or the transfusion codes did not match at all. Pretransfusion compatibility tests were performed on 2189 patient samples using this procedure. It was well accepted by both ward and blood bank staff. Two potential mismatched transfusions were avoided. These two clerical errors would not have been detected because neither patient had previous ABO grouping results.

Laparoscopy in the evaluation of the non-palpable undescended testes

AIM OF STUDY

To examine the role of laparoscopy in the evaluation of the non-palpable undescended testes in paediatric patients.

METHOD

A review of all laparoscopies performed for the evaluation of the non-palpable undescended testes in a children's hospital over a 12-month period was conducted. Special attention was paid to the patients' age, the location of the testes at the time of laparoscopy, the subsequent surgical procedures and the complications.

RESULTS

Sixteen boys underwent laparoscopy to localise 20 nonpalpable testes. 12 patients had unilateral disease while 4 had bilateral disease. 15 non-palpable testes were intraabdominal, 3 had inguinal testicular remnants and 2 had 'vanished'. A contralateral inguinal hernia was incidentally found in one patient. A patient with epididymal-gonadal non-union was not apparent at laparoscopy. There were no post-laparoscopic complications in all 16 patients.

CONCLUSION

Laparoscopy is safe and accurate in the evaluation of non-palpable testes in children. The accurate localisation of intraabdominal testes facilitates the development of an optimal surgical strategy.

Yuehchukene, a bis-indole alkaloid, and cyclophosphamide are active in breast cancer in vitro

Yuehchukene (YCK) is a novel bis-indole alkaloid with weak estrogenic activity. Biochemical studies showed that YCK could attenuate estrogenic action. In this study, the response of MCF-7, an estrogen-receptor-positive breast cancer cell line, under different combinations of estradiol, cyclophosphamide and YCK, was tested. From the dose-response curve, we discovered that 10(-2) M cyclophosphamide, even in its so-called 'bio-inert' form, could inhibit MCF-7 cell growth. However, the cytotoxic effect of cyclophosphamide was lost by reducing its concentration to approximately 1 x 10(-3) M. On the other hand, a low concentration ( approximately 10(-8)-10(-9) M) of YCK was found to potentiate the cytotoxic effect of cyclophosphamide on the MCF-7 cell line. Such an effect was absent in the estrogen-receptor-negative cell line MDA-MB-231. These findings, together with the dual role of a mixed estrogen and anti-estrogen effect, suggested that YCK and cyclophosphamide can be a potential combination in chemo-hormonal therapy for breast cancer.

Lack of structural rearrangement in c-kit and stem cell factor genes in Hong Kong Chinese patients with myelodysplastic syndromes or acute myeloid leukaemia

Stem cell factor is a haemopoietic growth factor that interacts with the c-kit-encoded transmembrane tyrosine kinase receptor during signal transduction in haemopoietic progenitor stem cells. We have screened 127 Chinese patients with myelodysplastic syndromes or acute myeloid leukaemia for structural rearrangements in the stem cell factor and c-kit genes using Southern blot analysis. No structural rearrangements were detected in any of the bone marrow samples that were tested. It seems that structural rearrangements in the stem cell factor and c-kit genes are rare in Hong Kong patients who have a haematological malignancy.

Randomized controlled trial of primary fistulotomy with drainage alone for perianal abscesses

PURPOSE

Primary fistulotomy may be advantageous for perianal abscesses because unlike ischiorectal abscesses, fistulas are more commonly found and can be laid open with full preservation of the external anal sphincters. Therefore, a randomized, controlled trial was conducted to compare primary fistulotomy with incision and drainage alone, specifically for perianal abscesses.

METHODS

Fifty-two consecutive patients (43 males; mean age, 40 (standard error of mean, 2) years) with perianal abscesses were randomized to treatment by either incision and drainage (controls; N = 28) or fistulotomy (N = 24). Patients were followed up clinically for a mean of 15.5 (standard error of the mean, 0.7) months. Anorectal manometry was also performed before, six weeks, and three months after surgery.

RESULTS

Persistent fistulas developing after surgery were significantly more common after incision and drainage (N = 7; 25 percent) than after fistulotomy (N = 0; P = 0.009). One patient in each group was also found to have a residual abscess, which required repeat drainage. All patients remained fully continent. The anal pressures after incision and drainage and fistulotomy were not significantly different. Operative time, hospital stay, and time for the wound to heal completely were the same in both groups.

CONCLUSIONS

Primary fistulotomy at the time of drainage for perianal abscesses results in fewer persistent fistulas and no added risk of fecal incontinence.

Low frequency of c-kit expression and detection of an aberrant Kit message among Hong Kong Chinese myelogenous leukaemia patients

The c-kit proto-oncogene encodes a transmembrane tyrosine kinase receptor. It is expressed by the primitive CD34 positive haemopoietic stem cells and interacts with the Kit ligand for signal transduction. It was reported to be expressed in over 80% of acute myelogenous leukaemia (AML) patients in North America and Japan. We analyzed 20 AML patients for c-kit expression using either Northern blot analysis or flow cytometry with the YB5.B8 anti-c-kit antibodies. Only 6 out of 20 AML patients expressed the c-kit mRNA or protein product. However, a previously unreported abnormal sized 1.7-1.9 kb transcript was detected in the blast cells of 1 AML patient, 1 acute mixed lineage leukaemia patient and 1 chronic myelogenous leukaemia (CML) patient in myeloblastic transformation. Our data suggested that in most Hong Kong Chinese AML patients, leukaemia transformation may have occurred at a c-kit negative stage. Alternatively, the abnormal sized c-kit transcript that was detected in some Chinese myeloid leukaemia patients may represent an aberrant c-kit receptor that plays an important role in leukaemogenesis.

The results of open acromioplasty in impingement syndrome--a retrospective study

Many published reports have reported generally good results of open acromioplasty in shoulder impingement syndrome. This paper studied retrospectively the results of open acromioplasty done in the Singapore General Hospital. A total of 23 open acromioplasties performed on 22 patients with shoulder impingement syndrome were studied. The post-operative results of the acromioplasties were evaluated using the University of California, Los Angeles (UCLA) shoulder scoring system. With the UCLA shoulder scoring system, results were excellent or good in 14 (60.8%), fair in 7 (30.5%) and poor in 2 (8.7%). At the same time the male sex was identified to have statistically significant better results as compared to the females. There was a trend towards poorer results in those at or above 50 years of age, duration of symptoms of less than 2 years and those with acromiohumeral distance of less than or equal to 1.0 cm. The presence of rotator cuff tears and the duration of follow-up were found not to have any bearing on the post-operative outcome. This procedure seems to be reasonably effective and safe. Careful patient selection and early post-operative rehabilitation with physiotherapy is of utmost importance.

Expression of an abnormal sized c-kit transcript in Hong Kong Chinese acute lymphoblastic leukaemia patients

Blast cells from a majority of acute myelogenous leukaemia (AML) patients express c-kit mRNA. However, c-kit expression has not been observed in patients with acute lymphoblastic leukaemia (ALL) and lymphoproliferative disease. We report here the detection of an abnormal sized c-kit mRNA in two Hong Kong Chinese patients with pre-B ALL and common ALL.

Provision of an out-of-hours blood banking service at a satellite hospital without blood bank staff

With limited health care resources and financial constraints, many hospitals have to reduce their service. Computer crossmatching has been accepted as a safe crossmatching procedure for patients without clinically significant alloantibodies. We report here a novel way of providing an out-of-hours blood banking service at a satellite hospital. The system is easy to introduce and can provide a safe transfusion service to small hospitals without stationing blood banking staff at these hospitals after regular working hours.

The effects of a self-educating blood component request form and enforcements of transfusion guidelines on FFP and platelet usage. Queen Mary Hospital, Hong Kong. British Committee for Standards in Hematology (BCSH)

Despite establishment of transfusion guidelines and feedback intervention, FFP and platelet transfusion were still inappropriate in many clinical situations at our hospital. Many physicians never read or referred to the guidelines when they were ordering FFP and platelet transfusion. A new blood component request form with the guidelines printed on it was designed to facilitate physician education and enforcement of these transfusion guidelines. The form was well accepted by junior house staff and inappropriate transfusion was significantly reduced.

The impact of a gel system on routine work in a general hospital blood bank

The gel system has been reported to be more sensitive and specific than the conventional tube indirect antiglobulin test (IAT) for antibody screening. However, a major concern about the gel system is its cost. A cost analysis study was therefore conducted at our hospital. The gel system costs more than the conventional tube IAT per test; however, the total staff and reagent costs per year were about equal, because of staff savings. Workload and cost per patient requiring blood were reduced using the gel system.

Experimental infection of turkeys with infectious bursal disease virus and the effect on the immunocompetence of infected turkeys

Turkeys of various ages were infected with strains of infectious bursal disease virus (IBDV). Pathological signs of infection were detected only in turkeys 1 day old when infected. No differences in antibody responses to IBDV or virus recovery were observed between turkeys of various ages at the time of infection. Cellular and humoral immune responses were suppressed following infection of day-old turkeys. The effects varied with virus strain.