Thrombocytopenia in pregnancy - pathogenesis and diagnostic approach

Thrombocytopenia (TP) affects 7-10% of pregnant women. It occurs 4 times more frequently in pregnancy than in the non-pregnant women population. Women with thrombocytopenia in pregnancy are a heterogeneous and poorly known group. There are several possible causes of thrombocytopenia in pregnancy. The most common are: gestational thrombocytopenia (GE) (60-75%), preeclampsia (PE) and HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome associated TP (21%), and idiopathic immune thrombocytopenia (ITP) (3-10%). Although thrombocytopenia diagnosed in pregnancy in most cases has a mild course, it has also been reported to be associated with a higher rate of preterm birth and premature detachment of the placenta. Some cases of severe thrombocytopenia with systemic involvement are associated with high risk of serious perinatal complications and require early diagnosis, careful clinical monitoring and medical treatment. The differential diagnosis and proper assessment of clinical risk of TP during pregnancy may be of great concern. The article discusses these issues, focusing on pathophysiology of TP in pregnancy.

[Trials of casual treatment of silicosis]

Silica-induced lung injury and the development of silicosis is one of the major occupational diseases. Accumulation and deposition of respirable dust containing silica mineral particles in the lung produces chronic lung disease characterized by granulomatous and fibrotic lesions. Knowledge of precise mechanisms, which induce this process is still limited, hence problems faced in the treatment of silicosis, especially the casual one. This article describes various trials of casual silicosis treatment with tetrandrine (Tet), isolated from the root of Stephania tetrandra, tumor necrosis factor (TNF) antagonists, polyvinyl-pyridine-N-oxide (PVNO), aluminum compounds, corticosteroids or bronchoalveolar lavage (BAL). The existing methods are not sufficient, which warrants further investigations. At present, prevention of the disease and treatment of its complications are most important.

[Distribution of conduction velocity in the ulnar nerve among lead exposed workers]

BACKGROUND

Neuropathy can be one of the symptoms of the toxic effect of lead on the nervous system. The aim of this work was to perform clinical and neurophysiological assessment of the peripheral nervous system in workers exposed to lead.

MATERIALS AND METHODS

The study included 34 exposed workers and 20 healthy controls. Motor (ulnar, peroneal) and sensory (ulnar, sural) conduction velocity as well as conduction velocity distribution in ulnar n. and EMG from the I. interosseus muscle were assayed. The whole blood value of Pb 400 microg/l was adopted as a borderline between workers with low and increased blood lead concentrations. The FEP value of 70 microg/100 ml erythrocytes was the borderline between those without or with biochemical signs of Pb loading. The workers' age and duration of occupational exposure did not differ significantly between the study and control groups.

RESULTS

None of the workers showed clinical signs of neuropathy or abnormalities in routine neurographic examination. As compared with controls, a significantly lowered conduction in slow-conducting motor fibers and neurogenic changes in EMG were observed in workers with the whole blood Pb concentration over 400 microg/l and in workers with FEP level over 70 tig/100 ml erythrocytes.

CONCLUSION

Neurotoxic effect of Pb on peripheral nerves is manifested by the damage of slow-conducting motor nerves fibers when overt neuropathy is not yet visible.

[The effect of chronic exposure to lead and cadmium on lipid peroxidation in the rat brain]

BACKGROUND

The aim of the study was to evaluate the impact of exposure to lead and cadmium on concentrations of some lipids, lipid peroxidation, enzymatic and non-enzymatic efficiency of antioxidants in the rat brain as well as the effect of combined exposure to metals on the lipid parameters and the activity of antioxidative system. The authors also compared the results in order to detect interactions between these two heavy metals.

MATERIALS AND METHODS

The study used the model of chronic, sub-clinical intoxication of lead and/or cadmium in Buffalo rats.

RESULTS

The tests involved the determination of lead and cadmium concentrations in the rat blood, superoxide dismutase activity, total cholesterol, lipid peroxides, and levels of vitamins C and E in tissue homogenates.

CONCLUSIONS

Single and combined exposures to small doses of lead and cadmium in rats results in the changed parameters showing the stimulation of lipid peroxidation and antioxidative system along with interactions in their influence.