Galectin-3 Is a Natural Binding Ligand of MCAM (CD146, MUC18) in Melanoma Cells and Their Interaction Promotes Melanoma Progression.

Melanoma cell adhesion molecule (MCAM, CD146, MUC18) is a heavily glycosylated transmembrane protein and a marker of melanoma metastasis. It is expressed in advanced primary melanoma and metastasis but rarely in benign naevi or normal melanocytes. More and more evidence has shown that activation of the MCAM on cell surface plays a vital role in melanoma progression and metastasis. However, the natural MCAM binding ligand that initiates MCAM activation in melanoma so far remains elusive. This study revealed that galectin-3, a galactoside-binding protein that is commonly overexpressed in many cancers including melanoma, is naturally associated with MCAM on the surface of both skin and uveal melanoma cells. Binding of galectin-3 to MCAM, via O-linked glycans on the MCAM, induces MCAM dimerization and clustering on cell surface and subsequent activation of downstream AKT signalling. This leads to the increases of a number of important steps in melanoma progression of cell proliferation, adhesion, migration, and invasion. Thus, galectin-3 is a natural binding ligand of MCAM in melanoma, and their interaction activates MCAM and promotes MCAM-mediated melanoma progression. Targeting the galectin-3-MCAM interaction may potentially be a useful therapeutic strategy for melanoma treatment.

Modified sugar beet pectin induces apoptosis of colon cancer cells via an interaction with the neutral sugar side-chains.

Pectins extracted from a variety of sources and modified with heat and/or pH have previously been shown to exhibit activity towards several cancer cell lines. However, the structural basis for the anti-cancer activity of modified pectin requires clarification. Sugar beet and citrus pectin extracts have been compared. Pectin extracted from sugar beet pulp only weakly affected the viability of colon cancer cells. Alkali treatment increased the anti-cancer effect of sugar beet pectin via an induction of apoptosis. Alkali treatment decreased the degree of esterification (DE) and increased the ratio of rhamnogalacturonan I (RGI) to homogalacturonan. Low DE per se did not play a significant role in the anti-cancer activity. However, the enzymatic removal of galactose and, to a lesser extent, arabinose from the pectin decreased the effect on cancer cells indicating that the neutral sugar-containing RGI regions are important for pectin bioactivity.

Rhamnogalacturonan I containing homogalacturonan inhibits colon cancer cell proliferation by decreasing ICAM1 expression.

Pectin modified with pH, heat or enzymes, has previously been shown to exhibit anti-cancer activity. However, the structural requirements for modified pectin bioactivity have rarely been addressed. In this study several pectin extracts representing different structural components of pectin were assessed for effects against colon cancer cells. Rhamnogalacturonan I (RGI) extracts reduced proliferation of DLD1 and HCT116 colon cancer cells in a dose- and time-dependent manner. RGI reduced ICAM1 gene expression and siRNA-mediated knockdown of ICAM1 expression decreased cell proliferation providing a potential novel mechanism for the anti-cancer activity of pectin. Structural analysis of bioactive and non-bioactive RGIs suggested that a homogalacturonan component is maybe essential for the anti-proliferative activity, furthering the understanding of the structural requirements for pectin bioactivity.

Is serial testing required to diagnose imported malaria in the era of rapid diagnostic tests?

Exclusion of malaria traditionally requires three negative serial thick and thin blood films. However, many clinical laboratories now routinely perform rapid diagnostic tests (RDTs) in addition to blood films when malaria is suspected. We sought to determine whether serial testing is necessary in this setting. We examined 388 cases of malaria diagnosed during 1999-2010 at three laboratories in Melbourne, Australia. For each case, we ascertained whether the diagnosis was made on initial or follow-up testing. Nine cases (3.5%) were diagnosed after a negative initial blood film and RDT: 7 Plasmodium vivax, 1 P. ovale, and 1 P. falciparum. Of four case-patients with P. vivax in which clinical data were available, all had recent exposure to antimalarial medication. Our data suggest that among patients who have not received recent anti-malarial therapy, and when RDTs are performed and blood films are prepared, most malaria diagnoses are made by using the first set of tests.

Fibrinogen Melbourne: a novel congenital hypodysfibrinogenemia caused by γ326Cys-Phe in the fibrinogen γ chain, presenting as massive splanchnic venous thrombosis.

Congenital dysfibrinogenemias are characterized by structural abnormalities in fibrinogen, which may lead to abnormal function. Fibrinogen has critical roles in coagulation, platelet aggregation and fibrinolysis; accordingly, abnormal fibrinogen function can result in a clinical phenotype, which varies from asymptomatic (around 55%) to bleeding (25%) and/or thrombosis (20%). We describe a novel γ326Cys→Phe mutation in the fibrinogen γ gene causing hypodysfibrinogenemia associated with life-threatening thrombosis in a family from Melbourne, Australia.

Post-arrival health screening in Karen refugees in Australia.

OBJECTIVE: To document the prevalence of nutritional deficiencies, infectious diseases and susceptibility to vaccine preventable diseases in Karen refugees in Australia. DESIGN: Retrospective audit of pathology results. SETTING: Community based cohort in Melbourne over the period July 2006-October 2009. PARTICIPANTS: 1136 Karen refugee children and adults, representing almost complete local area settlement and 48% of total Victorian Karen humanitarian intake for the time period. MAIN OUTCOME MEASURES: Prevalence of positive test results for refugee health screening, with breakdown by age group (<6 years, 6-11 years, 12-17 years, 18 years and older). RESULTS: Overall prevalence figures were: anaemia 9.2%, microcytosis 19.1%, iron deficiency 13.1%, low vitamin B(12) 1.5%, low folate 1.5%, abnormal thyroid function tests 4.4%, vitamin D<50 nmol/L 33.3%, hypocalcaemia 7.4%, raised alkaline phosphatase 5.2%, abnormal liver transaminases 16.1%, hepatitis B surface antigen positive 9.7%, hepatitis B surface antibody positive 49.5%, isolated hepatitis B core antibody positive 9.0%, hepatitis C positive 1.9%, eosinophilia 14.4%, Schistosoma infection 7%, Strongyloides infection 20.8%, malaria 0.2%, faecal parasites 43.4%. Quantiferon-gold screening was positive in 20.9%. No cases of syphilis or HIV were identified. Serological immunity to vaccine preventable diseases was 87.1% for measles, 95% for mumps and 66.4% for rubella; 56.9% of those tested had seroimmunity to all three. CONCLUSIONS: Karen refugees have high rates of nutritional deficiencies and infectious diseases and may be susceptible to vaccine preventable diseases. These data support the need for post-arrival health screening and accessible, funded catch-up immunisation.

Detection of BRAF mutations in patients with hairy cell leukemia and related lymphoproliferative disorders.

Hairy cell leukemia has been shown to be strongly associated with the BRAF V600E mutation. We screened 59 unenriched archived bone marrow aspirate and peripheral blood samples from 51 patients with hairy cell leukemia using high resolution melting analysis and confirmatory Sanger sequencing. The BRAF V600E mutation was detected in 38 samples (from 36 patients). The BRAF V600E mutation was detected in all samples with disease involvement above the limit of sensitivity of the techniques used. Thirty-three of 34 samples from other hematologic malignancies were negative for BRAF mutations. A BRAF K601E mutation was detected in a patient with splenic marginal zone lymphoma. Our data support the recent finding of a disease defining point mutation in hairy cell leukemia. Furthermore, high resolution melting with confirmatory Sanger sequencing are useful methods that can be employed in routine diagnostic laboratories to detect BRAF mutations in patients with hairy cell leukemia and related lymphoproliferative disorders.

The unrecognized psychosocial factors contributing to bleeding risk in warfarin therapy.

BACKGROUND AND PURPOSE: Warfarin is an effective drug for the prevention of thromboembolism in the elderly. The major risk for patients taking warfarin is bleeding. We aimed to assess the impact of psychosocial factors, including mood, cognition, social isolation, and health literacy on warfarin instability among community-based elderly patients. METHODS: A case-control study was conducted between March 2008 and June 2009 in a community-based setting. Cases were patients previously stabilized on warfarin who recorded an international normalized ratio≥6.0. Control subjects were patients whose international normalized ratio measurement was maintained within the therapeutic range. Patient interviews investigated potential predisposing factors to elevated International Normalized Ratio levels. RESULTS: A total of 486 patients were interviewed: 157 cases and 329 control subjects, with an approximate mean age of 75 years. Atrial fibrillation was the most common primary indication. Adjusted multivariate logistic regression revealed impaired cognition (OR, 1.9; 95% CI, 1.0 to 3.6), depressed mood (OR, 2.2; 95% CI, 1.2 to 3.9), and inadequate health literacy (OR, 4.0;95% CI, 2.1 to 7.4) were associated with increased risk of an elevated International Normalized Ratio. CONCLUSIONS: This study identified impaired cognition, depressed mood, and inadequate health literacy as risk factors for warfarin instability. These had a similar impact to well-recognized demographic, clinical, and medication-related factors and are prevalent among the elderly. These findings suggest that elderly patients prescribed warfarin should be reviewed regularly for psychosocial deficits.

Who is responsible for the care of patients treated with warfarin therapy?

OBJECTIVE: To identify potential weaknesses in the system of managing warfarin therapy. DESIGN, PARTICIPANTS AND SETTING: A structured interview-based study of 40 community-dwelling patients taking warfarin and with an international normalised ratio > or = 6.0 and 36 of their treating doctors (35 general practitioners and 1 specialist), conducted between July and November 2007. Patients all received services from and were recruited sequentially by a large, private metropolitan pathology provider in Melbourne. MAIN OUTCOME MEASURES: Patients' demographic, clinical, cognitive and psychosocial characteristics, warfarin knowledge, medication complexity and adherence; and doctors' experience with, approach to and involvement in warfarin management, and their perception of responsibility for warfarin management and patient education. RESULTS: Interviews revealed multiple difficulties, including cognitive dysfunction, possible depression, and medication non-adherence, in 30 of 40 patients. Of 36 doctors interviewed, 12 were unaware of these difficulties in their patients. Five doctors considered they had sole responsibility for their patients' anticoagulation, while 15 confirmed a mutual relationship with the pathology service, and 16 deferred total responsibility to the pathology provider. Only 14/36 doctors reported conducting patient education at commencement of warfarin therapy, with the other 22 stating this was the responsibility of the initiating specialist, pathology service or dispensing pharmacist. CONCLUSIONS: There is a need for improved role clarification in coordinating warfarin management. We propose exploring the possibility of a Warfarin Suitability Score to assist better recognition of patients in whom treatment may be problematic, along with a model of care using practice nurses with GPs to facilitate optimal patient care.

Utilization of preoperative autologous blood donation in elective surgery.

BACKGROUND: The aim of the present paper was to review the pattern of collection and transfusion of autologous red cells for elective surgical procedures METHODS: Data on requests for preoperative autologous donation of blood were obtained from the Australian Red Cross Blood Service, Victoria and the Royal Melbourne Hospital for the calendar year 1998. The following information was collected: patient age, sex, surgery type, number of autologous units requested and collected and, if relevant, reasons for not achieving the requested collection. Transfusion of autologous units and any additional homologous units was confirmed from records at the blood banks of the Royal Melbourne Hospital and Melbourne Pathology (the pathology provider performing cross-matching for the majority of autologous units collected by Australian Red Cross Blood Service, Victoria). RESULTS: Over 12 months, 2803 units of autologous blood were requested and 2282 units collected from 1301 patients. The most common reason for failure to collect the number of units requested was insufficient time between referral and surgery. Of the autologous units collected, 73% were transfused giving a collection to transfusion ratio of 1.4. Sixty-eight per cent of patients received their autologous units only, 10% received both autologous and homologous units, while 22% were not transfused. For the majority of procedures, patients using preoperative autologous donation of blood had higher transfusion rates than those who did not use this. CONCLUSIONS: Ninety per cent of patients undergoing preoperative autologous donation of blood successfully avoided homologous blood exposure. However, preoperative autologous donation of blood is both wasteful and increases the incidence of transfusion in surgical procedures.

Use of red blood cell transfusions in surgery.

BACKGROUND: Limited blood supplies necessitate the rational use of blood products. The aim of the present study was to provide a basis for audits of red cell usage in surgery by benchmarking common practice. Application of the data to the construction of a maximum surgical blood order schedule may be relevant for centres that perform a serological crossmatch or who collect autologous units. METHODS: Data on surgical procedures identified by Commonwealth Medical Benefits Schedule item numbers, were collected retrospectively from theatre and blood bank records at the Royal Melbourne and Melbourne Private hospitals from May 1997 to April 1998. The percentage of procedures for which red cells were transfused, and the mean, median and range of units transfused for procedures with >/= 30% transfusion likelihood were identified. RESULTS: Over 12 months, 266 surgical procedure codes were itemized >/= 10 times each, contributing 12 300 data entries. Only 38 procedures demonstrated an incidence of transfusion of at least 30%. Most frequently transfused procedures included spinal fusion, total hip replacement, mandible/maxilla resection, prostatectomy and bladder excision. CONCLUSION: The number of common surgical procedures in which there is a 30% or greater likelihood that red cell transfusions will be given is limited. This benchmarking of common red cell usage is a first step in the process of determination of transfusion appropriateness.