Initiation of the extrinsic pathway of coagulation by human and rabbit alveolar macrophages: a kinetic study

We examined assembly and expression of the factor X activating complex on human and rabbit alveolar macrophages. Kinetic parameters of the factor X activating reaction were determined by functional titrations of factors VII and X with macrophage tissue factor (TF) added. We found rapid activation of factor X to Xa on alveolar macrophage surfaces. Detection of rapid factor Xa formation on macrophages required addition of exogenous factors VII and X. At plasma concentrations of the purified factors, factor Xa was formed on freshly isolated macrophages at approximately 5.4 pmol/min/10(6) cells. After macrophage maturation in culture for 20 hours with LPS (endotoxin) added, the factor X activation rate was increased two- to sixfold. The km' (apparent km) of TF-factor VII enzymatic complexes assembled on alveolar macrophages for factor X were (258 +/- 55 and 475 +/- 264 nmol/L for human and rabbit cells, respectively). The km' did not change during macrophage maturation in culture, but V'max (apparent Vmax) was consistently increased. The K1/2 of human factor VII (concentrations giving half maximal rates of factor X activation) for the interaction with human and rabbit alveolar macrophage TF were 0.191 +/- 0.096 and 1.7 +/- 0.7 etamol/L, respectively. The K1/2 were not significantly changed after maturation, whereas rates of Xa formation at saturation with factor VII were increased. The fast rates of factor X activation observed at physiologic concentrations of plasma-derived factors VII and X indicate that TF on alveolar macrophages is likely to provide sites for binding of factor VII and activation of factor X in vivo during clotting reactions associated with alveolar edema and inflammation.     

Polymorphisms in the tumor necrosis factor-alpha gene in Turkish women with pre-eclampsia and eclampsia

The genetic background predisposing pregnant women to pre-eclampsia/eclampsia (PE/E) is still unknown. The aim of the current study was to investigate whether there is an association between the TNF-alpha-308 and 850 polymorphisms and PE or eclampsia. In this study, 40 cases of eclampsia, 113 cases of PE and 80 normotensive control cases were genotyped for the TNF-alpha-G-308A and C-850 polymorphisms. At position 308, the replacement of Guanine with Adenosine was denoted as TNF2. We found a significant difference between the TNF2 allele frequencies of the eclamptic, pre-eclamptic and normotensive controls. TNF2 (AA) polymorphism frequency was significantly higher among the eclamptics and pre-eclamptics (control : 5%, PE : 13.3%, E : 12.9%). A significantly different genotype distribution of C-850T polymorphism was observed between the PE/E and control groups, with the frequency of the variant TT genotype being significantly reduced in the preeclamptics (PE : 17% ; E : 17.5%) when compared with the control group (24.3%). We have demonstrated an association between TNF-alpha polymorphisms and pre-eclampsia susceptibility. However, it is not known whether C-850T polymorphism has a functional effect on the TNF-alpha gene. In addition, it was not possible to determine whether this polymorphism promotes the progression from PE to eclampsia because of no statistically significant difference between eclampsia and the controls.     

Trends in pemphigus research over 15 years

Background Although pemphigus is a rare autoimmune blistering disease, it attracts the attention of physicians of many disciplines. Objective This study aims to assess the number of articles on pemphigus that have been published over 15 years in dermatology vs. non‐dermatology medical journals, and to evaluate the quality of available evidence. Methods PubMed was searched for articles on pemphigus published between 1 January 1993 to 31 December 2007 using the search word pemphigus. Articles were characterized by publication type and journal type per year. Regression analysis was used to determine the effect of year of publication on number of publications of each type. Results The search yielded 2032 publications on pemphigus during the evaluation period. Sixty‐one per cent were published in dermatology journals. Overall, the number of publications increased linearly with time. Most of this increase was accounted for by publications in non‐dermatology journals. There was an increase in clinical trials over the course of the study period. The number of certain publications with lower quality of evidence, mainly case reports and letters to the editor, increased significantly in the last few years. There was no increase in publications with high quality of evidence. Conclusions The increase on data from non‐dermatology disciplines is a welcome contribution. Nevertheless, high‐quality evidence on pemphigus is still lacking. We trust that the current trend towards evidence‐based dermatology will impact future research on this severe disease.     

Nasal dermoids: the significance of a midline punctum

Nasal dermoids are rare and their diagnosis is often delayed until complications occur. Signs such as a midline nasal punctum may be noted at birth but the significance of this finding frequently passes unrecognised. The cases are reported of two patients which illustrate the typical presentation of these lesions and their subsequent management is discussed.     

Prospective randomized comparison of morning versus night daily single subcutaneous administration of granulocyte-macrophage-colony stimulating factor in patients with soft tissue or bone sarcoma

BACKGROUND: Hematopoietic growth factors (HGFs) have been used to reduce the neutropenic complications of cytotoxic chemotherapy so that higher doses may be given. The authors have previously shown that endogenous serum granulocyte-colony stimulating factor (G-CSF) and granulocyte-macrophage-colony stimulating factor (GM-CSF) levels at night (p.m.) were significantly higher than those in the morning (a.m.). METHODS: Twenty-four patients with soft tissue or bone sarcoma who were treated with high dose ifosfamide-based chemotherapy were enrolled in this study. Patients were randomized to either a.m. or p.m. treatment. GM-CSF was administered at a dose of 5 microg/kg/day at 10 a.m. or 10 p.m., beginning 36-48 hours after the last chemotherapy dose. GM-CSF therapy was continued until the neutrophil count exceeded 1,000/mm3 for 2 consecutive days. Leukocyte, neutrophil, monocyte, and platelet counts were measured immediately before GM-CSF administration and exactly 12 hours after the first dose of GM-CSF, and every 24 hours until 3 days after the cessation of GM-CSF. RESULTS: The mean duration of Grade 3-4 neutropenia was 5.3 +/- 0.4 days for the a.m. treatment arm and 6.5 +/- 0.3 days for the p.m. treatment arm (P = 0.017). Although the duration of neutropenia in the a.m. arm was significantly shorter than in the p.m. arm, there were no differences related to the number of febrile neutropenic episodes or the duration of antibiotic administration. Also, there were no differences in the side effects observed in the a.m. and p.m. arms. CONCLUSIONS: The finding of 1.2 days' difference in the duration of Grade 3-4 neutropenia warrants further study of chronotherapy with HGFs.     

Interferon-alpha as maintenance therapy in patients with multiple myeloma

Schaar et al. [1] investigated the role of interferon-alpha(IFN) as maintenance therapy in patients with multiple     

The acute effect of trimetazidine on the high frequency fatigue in the isolated Rat diaphragm muscle

The objective of this study was to determine the acute effect of trimetazidine (TMZ) on the pre-fatigue, fatigue and post-fatigue contractile characteristics and tension-frequency relationships of isolated rat diaphragm muscle. Muscle strips were taken from the ventral-costal aspects of the diaphragm muscle of rats killed by decapitation. The muscle strips were suspended in organ baths containing Krebs solution, with a gas mixture of 95% O2 and 5% CO2 at 37 degrees C and pH 7.35-7.45. After determining the thermoregulation and optimum muscle length the muscles were subjected to direct supramaximal stimulation with 0.05 Hz frequency square pulses for periods of 0.5 msec to obtain control values. After adding 5 x 10(-6) and 5 x 10(-5) M trimetazidine solution to the respective bath media, the contractile parameters of the muscles were recorded. The contractile parameters were also recorded for both the trimetazidine and trimetazidine-free media after application of the high frequency fatigue protocols. Later, the tension-frequency relationship was determined by applying stimulating pulses of 10, 20, 50 and 100 Hz to the muscle strips. Whilst the twitch tension obtained from the 5 x 10(-6) and 5 x 10(-5) M trimetazidine media showed numerical increases compared to that of the controls, these were not statistically significant (p>0.05). The contraction time exhibited a dose dependent increase (p<0.001), whilst the contraction and relaxation rates did not differ significantly. The isometric contraction forces obtained with the different stimulating frequencies showed a significant increase in the tetanic contraction only at 100 Hz (p<0.05). A comparison of the pre- and post-fatigue twitch tensions in the trimetazidine media showed the post- fatigue twitch tensions to be significantly higher than those of the pre-fatigue contraction forces (p<0.05). In the 5 x 10(-6) and 5 x 10(-5) M trimetazidine media the increases in the post-fatigue contraction force were 22 and 30%, respectively. These results demonstrated that in isolated rat diaphragm muscle, TMZ significantly limited the mechanical performance decrease during fatigue. It is our opinion that trimetazidine contributed to the observed fatigue tolerance by eliminating the factors of fatigue, due to preservation of intracellular calcium homeostasis, provision of the ATP energy levels needed by ATPase dependent pumps and especially by keeping the intracellular pH within certain limits.