Investigation of the 22q11.2 candidate region in patients with midline facial defects with hypertelorism.

Midline facial defects with hypertelorism (MFDH) are mainly characterized by ocular hypertelorism and bifid nose. They are often associated with structural and functional anomalies of the central nervous system similar to those found in 22q11.2 deletion syndromes. In addition, there are some isolated reports of MFDH and 22q11.2 deletion. These findings suggest that MFDH may be part of the spectrum of 22q11.2 deletion syndromes. To test this hypothesis, 10 individuals with MFDH were analyzed by fluorescent in situ hybridization (FISH), but no 22q11.2 deletion was detected. In view of this result, the TBX1 gene located within the 22q11.2 candidate region was screened. A new sequence variant (1132GA) was identified in one patient. This variant was not found in 110 control individuals genotyped. Considering the rarity of this condition and results of this study, the involvement of the 22q11.2 chromosomal region in the pathogenesis of MFDH could not be excluded.

Heat shock protein 27 is involved in SUMO-2/3 modification of heat shock factor 1 and thereby modulates the transcription factor activity.

Heat shock protein 27 (HSP27) accumulates in stressed cells and helps them to survive adverse conditions. We have already shown that HSP27 has a function in the ubiquitination process that is modulated by its oligomerization/phosphorylation status. Here, we show that HSP27 is also involved in protein sumoylation, a ubiquitination-related process. HSP27 increases the number of cell proteins modified by small ubiquitin-like modifier (SUMO)-2/3 but this effect shows some selectivity as it neither affects all proteins nor concerns SUMO-1. Moreover, no such alteration in SUMO-2/3 conjugation is achievable by another HSP, such as HSP70. Heat shock factor 1 (HSF1), a transcription factor responsible for HSP expression, is one of the targets of HSP27. In stressed cells, HSP27 enters the nucleus and, in the form of large oligomers, binds to HSF1 and induces its modification by SUMO-2/3 on lysine 298. HSP27-induced HSF1 modification by SUMO-2/3 takes place downstream of the transcription factor phosphorylation on S303 and S307 and does not affect its DNA-binding ability. In contrast, this modification blocks HSF1 transactivation capacity. These data show that HSP27 exerts a feedback inhibition of HSF1 transactivation and enlighten the strictly regulated interplay between HSPs and HSF1. As we also show that HSP27 binds to the SUMO-E2-conjugating enzyme, Ubc9, our study raises the possibility that HSP27 may act as a SUMO-E3 ligase specific for SUMO-2/3.

Phenotypic APC resistance in carriers of the A20210 prothrombin mutation is associated with an increased risk of venous thrombosis.

We hypothesized that increased prothrombin levels associated with G20210A prothrombin gene mutation could affect the results of activated protein C (APC) resistance phenotype and increase the risk of venous thrombosis (VT). The increasing addition of purified prothrombin in plasma of 90 normal subjects resulted in a parallel significant increase of APC resistance. Significantly different mean n-APC-SR in 879 GG20210 subjects compared to 27 heterozygous carriers of isolated G20210A mutation was observed (1.0 +/- 0.12 vs. 0.95 +/- 0.11; P = 0.02) in a random sample of 906 normal population subjects. Twenty-seven families with VT and isolated G20210A mutation consecutively diagnosed during 1998-1999 were evaluated. Mean n-APC-SR was significantly lower in the 80 G20210A carriers compared to 58 GG 20210 relatives investigated, even after sex and age adjustment (0.92 +/- 0.08 vs. 1.05 +/- 0.13; P < 0.0001). A strong relationship between plasma prothrombin level and n-APC-SR was observed in the families. When n-APC-SR values were grouped in tertiles, the odds ratio for VTE, after exclusion of the index cases and adjustment for 20210 status, for subjects in the lowest tertile (n-APC-SR 0.73-0.90) was 4.58 (95% CI 0.78-26.88) compared to upper tertile (n-APC-SR 1.01-1.30). In conclusion, in subjects with G20210A mutation APC resistance is significantly increased, correlates with plasma prothrombin level and the carriers with the lowest APC resistance values have an increased risk of VTE.

Platelet activation and modulation of the induction of nitric oxide synthase in the conscious rat.

Injection of lipopolysaccharide (LPS) (Salmonella W. Typhosa i.v. bolus) into conscious rats, induced a rapid drop of circulating platelets analogous to that induced by ADP. The animals showed a small fall in mean arterial blood pressure (MABP), an increase in heart rate and a significant increase in plasma nitrite and nitrate level. This result is consistent with the stimulation of an inducible NO synthase (i-NOS). The administration of the stable prostacyclin analogue, iloprost plus ADP or LPS, significantly protected against the decrease in free platelet number induced by ADP or LPS. The plasma nitrite and nitrate level stimulated by LPS was significantly reduced by iloprost and also by prostacyclin. These results are consistent with an inhibition of i-NOS by agents that increase the intracellular level of cAMP. The administration of the NO donor S-Nitroso-N-acyl-D-penicillamine (SNAP) plus ADP or LPS, significantly prevented thrombocytopenia induced by ADP and by LPS. SNAP did not decrease the plasma nitrite and nitrate level stimulated by LPS; furthermore it induced a significant increase of heart rate, without affecting MABP, suggesting a direct accelerating effect of NO on the sino-atrial node. The administration of S-nitroso-glutathione (GSNO), a stable nitrosothiol, plus ADP or LPS, significantly prevented thrombocytopenia induced by ADP but not by LPS. GSNO significantly reduced the plasma nitrite and nitrate level stimulated by LPS. These data demonstrate that the L-Arginine: NO pathway in vivo may be modulated by prostanoids and that compounds which increase cAMP, such as iloprost, are able to protect against LPS-induced early thrombocytopenia.

Serum IgA and gold toxicity in rheumatoid arthritis: lack of predicting value.

The previously reported predictive value of serum IgA for gold toxicity was investigated by measuring such immunoglobulins in 114 patients affected with rheumatoid arthritis and treated with gold salts over a period of 36 months. Side effects were observed in 41 cases (35.9%) (toxic group), mostly within the first year of treatment. Basal levels of IgA were normal in all but 2 patients who maintained low levels throughout the follow-up but did not show any toxic effects. Before therapy and during gold salt administration no difference in serum IgA was noted between the toxic and the non-toxic group. After 6 months of therapy a significant decrease (p less than 0.05) in serum IgA (although never below normal limits) was detected in the toxic group as compared to both the basal values of the same group and the values of the non-toxic group at the same control. Moreover, we did not find any difference in serum IgA between toxic patients with and without mucocutaneous reactions. In our experience the monitoring of serum IgA is not useful in predicting gold toxicity.

[Proglumetacin for the treatment of inflammatory and degenerative arthropathies]. / La proglumetacina per il trattamento delle artropatie infiammatorie e degenerative.

Twenty patients with inflammatory (15) or degenerative (5) joint disorders had been treated with 450 mg/day of proglumetacin during 35 +/- 18 days. Articular symptoms showed a definite and continued improvement, particularly evident during the initial 15 days of treatment on both painful and inflammatory components. The final physician's evaluation rated 75% of results as excellent or good, versus 15% of poor (3 patients, one of whom already refractory to diclofenac). The tolerance was defined as excellent to good in 90% of patients: one (5%) was dropped out upon the onset of sweating and palpitation, already observed with other drugs. Overall, only one case each of heartburn, anorexia and diarrhoea were considered as possibly related to the treatment. Laboratory tests did not show any variation that could be attributed to the drug. Proglumetacin therefore, by force of its efficacy and safety, appears to be particularly suited as a first-choice drug for the management of both inflammatory and degenerative joint disorders.