Identification of Inorganic Pyrophosphate in Human Platelets and Its Release on Stimulation with Thrombin

Serum inorganic pyrophosphate (PPi) levels were consistently two- to threefold higher than plasma PPi prepared from the same blood. PPi was found in platelets in amounts ranging from 1.4 to 3 nmol/10(8) cells, using three different techniques for quantification. These levels are approximately 800 times higher than the mean PPi concentration in normal plasma and approximate the levels of ADP found in platelets by other workers.About 50% of platelet PPi was specifically released extracellularly after stimulation with thrombin. Timed release experiments showed a pattern of release that resembled that described for ADP and ATP. This pattern was clearly different from that shown by platelet calcium, serotonin, or beta-glucuronidase. Platelet inorganic pyrophosphatase was not released into the supernate in detectable amounts.Platelets from patients with nucleotide storage pool deficiency showed greatly reduced levels of PPi as compared with control. There was no detectable release of PPi into extracellular medium after thrombin addition to a suspension of these platelets.     

Multifocal angiostatic therapy: an update

Multifocal angiostatic therapy (MAT) is a strategy that seeks to impede cancer-induced angiogenesis by addressing multiple targets that regulate the angiogenic capacity of a cancer and/or the angiogenic responsiveness of endothelial cells, using measures that are preferentially, but not exclusively, nutraceutical. A prototype of such a regimen has been proposed previously, composed of green tea polyphenols, fish oil, selenium, and high-dose glycine, complementing a low-fat vegan diet, exercise training, and the copper-sequestering drug tetrathiomolybdate (TM). A review of more recent evidence suggests additional agents that could appropriately be included in this regimen and clarifies to some extent the mechanisms of action of its constituents. Diindolylmethane, a widely available crucifera-derived nutraceutical, has inhibited cancer growth in several mouse xenograft models; this effect may be largely attributable to an angiostatic action, as concentrations as low as 5 to 10 muM inhibit proliferation, migration, and tube-forming capacity of human endothelial cells in vitro, and a parenteral dose of 5 mg/kg markedly impairs matrigel angiogenesis in mice. Silymarin/silbinin, which has slowed the growth of human xenografts in a number of studies, suppresses the proliferation, migration, and tube-forming capacity of endothelial cells and inhibits vascular endothelial growth factor (VEGF) secretion by a range of human cancer cell lines, in concentrations that should be clinically feasible. The angiostatic activity of orally administered green tea now appears likely to reflect inhibition of the kinase activity of VEGFR-2. Glycine's angiostatic activity may be attributable to a hyperpolarizing effect on endothelial cells that decreases the activity of NADPH oxidase, now known to promote tyrosine kinase signaling in endothelial cells. The ability of TM to suppress cancer cell production of a range of angiogenic factors results at least in part from a down regulation of NF-kappaB activation. Dual-purpose molecular targets, whose inhibition could be expected to decrease the aggressiveness and chemoresistance of cancer cells while simultaneously impeding angiogenesis, include NF-kappaB, cox-2, c-Src, Stat3, and hsp90; drugs that can address these targets are now in development, and salicylates are notable for the fact that they can simultaneously inhibit NF-kappaB and cox-2. The potential complementary of the components of MAT should be assessed in nude mouse xenograft models.     

Overexpression of neuropilin-1 promotes constitutive MAPK signalling and chemoresistance in pancreatic cancer cells

Neuropilin-1 (NRP-1) is a novel co-receptor for vascular endothelial growth factor (VEGF). Neuropilin-1 is expressed in pancreatic cancer, but not in nonmalignant pancreatic tissue. We hypothesised that NRP-1 expression by pancreatic cancer cells contributes to the malignant phenotype. To determine the role of NRP-1 in pancreatic cancer, NRP-1 was stably transfected into the human pancreatic cancer cell line FG. Signal transduction was assessed by Western blot analysis. Susceptibility to anoikis (detachment induced apoptosis) was evaluated by colony formation after growth in suspension. Chemosensitivity to gemcitabine or 5-fluorouracil (5-FU) was assessed by MTT assay in pancreatic cancer cells following NRP-1 overexpression or siRNA-induced downregulation of NRP-1. Differential expression of apoptosis-related genes was determined by gene array and further evaluated by Western blot analysis. Neuropilin-1 overexpression increased constitutive mitogen activated protein kinase (MAPK) signalling, possibly via an autocrine loop. Neuropilin-1 overexpression in FG cells enhanced anoikis resistance and increased survival of cells by > 30% after exposure to clinically relevant levels of gemcitabine and 5-FU. In contrast, downregulation of NRP-1 expression in Panc-1 cells markedly increased chemosensitivity, inducing > 50% more cell death at clinically relevant concentrations of gemcitabine. Neuropilin-1 overexpression also increased expression of the antiapoptotic regulator, MCL-1. Neuropilin-1 overexpression in pancreatic cancer cell lines is associated with (a) increased constitutive MAPK signalling, (b) inhibition of anoikis, and (c) chemoresistance. Targeting NRP-1 in pancreatic cancer cells may downregulate survival signalling pathways and increase sensitivity to chemotherapy.     

Maternal and Neonatal Factors Adversely Affecting Breastfeeding in the Perinatal Period

Background

Despite its known advantages, breastfeeding rates are low world over. Large number of factors affect breastfeeding. This study was designed to detect maternal and neonatal factors that adversely affect breastfeeding in the perinatal period.

Methods

A prospective, single-blinded study was conducted on randomly chosen mother-infant pairs in the maternity ward of a tertiary care service hospital. Only full term singletons born by normal vaginal delivery were studied. The B.R.E.A.S.T observation score and time spent by the infant at the mother''s breast were primary outcome variables. Maternal age, gravida, para status and education level were recorded. Birth weight, sex, gestation age of the infant and time interval from birth to observation were also recorded. Initial univariate analysis followed by multivariate analysis was performed using SPSS ver 7.5 software.

Results

A total of 54 mother-infant pairs formed the study group; 19(35.2%) were primigravidas. Primigravidas status of the mother led to significantly lower scores (p<0.04; 95% CI 0.10 to 3.62) as did maternal age < 26 years (p<0.04; 95% CI 0.2. to 3.46) on univariate analysis. Low birth weight (<2500 g) was the only neonatal factor that significantly lowered breastfeeding scores (p<0.02;95%Cl 0.56 to 6.31). On multivariate analysis only primigravida status was significantly associated with lower scores (p<0.02). The alpha value of the study was 5% and the power was 74%. Time spent by infant on breast was not significantly different between primigravida and non-primigravida mothers.

Conclusion

Primigravida status adversely affects breastfeeding scores; therefore counseling and support should be focused on this group. Extra care should also be taken to ensure adequate breastfeeding by younger mothers and in those with low birth weight infants. Larger studies with long-term follow up will be able to identify other factors and dertermine the effects of focused counseling and support in the perinatal period upon long-term breastfeeding rates.Key Words: Breastfeeding, Primigravida, Counseling     

Efficacy and Toxicity Profile of Methotrexate Chloroquine Combination in Treatment of Active Rheumatoid Arthritis

Background

The present study was conducted to study the efficacy and toxicity profile of methotrexate chloroquine combination in treatment of active rheumatoid arthritis.

Methods

24 patients of rheumatoid arthritis confirming to revised American Rheumatism Association (ARA) criteria were studied prospectively for twenty months. Clinical evaluation was made every 3 months. Clinical disease variables measured at each visit were number of joints with swelling, number of joints with tenderness and pain, duration of morning stiffness and physician and patient assessment of disease activity. Blood counts, liver function tests and other adverse effects due to drugs were monitored every 2 months.

Results

10 patients demonstrated more than 50% improvement. 4 patients withdrew from study, 2 because of excessive nausea and vomiting and 2 because of noncompliance. Other side effects noted were hyperpigmentation, photosensitivity, skin rashes, raised transaminases and stomatitis.

Conclusion

Methotrexate chloroquine combination has good efficacy and toxicity profile. Gastrointestinal side effects are most common and usually responsible for the discontinuation of the drugs.Key Words: Rheumatoid arthritis, Methotrexate, Chloroquine, Efficacy, Toxicity     

Management of distal humerus fractures

Fractures of the distal humerus are complex injuries that can be effectively treated with open reduction and internal fixation (ORiF). Exposure of a complex intra-articular fracture may best be achieved through a posterior approach with osteotomy of the olecranon process. The ulnar nerve must be identified and protected, the articular surface must be reduced anatomically, and rigid fixation must be applied to both the medial and lateral columns of the distal humerus. Range of motion should be initiated as soon as possible postoperatively. Complications such as ulnar neuropathy, elbow stiffness, heterotopic ossification, and nonunion should be treated aggressively. Total elbow arthroplasty represents an effective option for fractures that cannot be treated with ORIF.     

The posterior shearing tibial plateau fracture: treatment and results via a posterior approach

OBJECTIVES: This study was designed to describe the fracture patterns and early results of treatment of posterior shearing tibial plateau fractures. DESIGN: Retrospective case series. SETTING: Tertiary care hospital. PATIENTS: Thirteen patients identified from prospective trauma database with posterior shearing tibial plateau fractures. INTERVENTION: Open reduction and internal fixation through a posterior approach to the knee. MAIN OUTCOME MEASUREMENTS: Functional outcome assessed by Musculoskeletal Functional Assessment score and Visual Analogue Scale pain scores. Clinical and radiographic outcome. RESULTS: A consistent fracture pattern was identified with a primary, inferiorly displaced posteromedial shear fracture with variable amounts of lateral condylar impaction. The average duration of clinical patient follow-up was 20 (range, 13-27) months. All fractures healed after index surgery. Two complications (1 wound dehiscence and 1 flexion contracture) were all managed nonoperatively. Three independent surgeons graded patients' articular reduction, with good interobserver reliability (intraclass correlation coefficient = 0.82). The average Musculoskeletal Function Assessment dysfunction score for the 9 patients who responded was 19.5/100, and average resting Visual Analogue Scale pain score was 1.8 cm/10 cm, indicating good function. The functional outcome score was significantly related to the quality of articular reduction (P < 0.017, R = 0.456). CONCLUSIONS: Posterior shearing tibial plateau fractures form a consistent pattern. They can be successfully managed using a posterior approach with direct reduction and buttress fixation of articular fragments. Quality of articular reduction is one factor that influences short-term functional outcome.     

Birth weight and systemic lupus erythematosus

The fetal environment may be a contributing factor in the etiology of some adult diseases. This study examined whether birth weight, birth length and gestational age are associated with the subsequent development of systemic lupus erythematosus (SLE). The Marshfield Clinic Lupus Registry was searched to identify patients who were born at Saint Joseph's Hospital in Marshfield, Wisconsin, USA. Birth data on each case and five age-, sex-, and race-matched controls were recorded from medical and delivery room register records. Perinatal data were obtained for 23 cases and 115 controls. The unadjusted mean birth weight was similar for cases (3407 +/- 581 g) and controls (3422 +/- 514 g). Birth length was not different between groups. Birth weight adjusted for gestational age, analysed by conditional logistic regression, was not statistically significantly different between groups. We concluded that birth weight and length were similar among SLE cases and controls, suggesting that these perinatal characteristics are not associated with subsequent SLE.