Synthesis and physical properties of telechelic monodispersed diols 4. Monoaddition of 10-undecenol to novel dithiols

The synthesis of novel telechelic monodispersed diols produced from the radical monoaddition of an excess of 10-undecenol with novel α, ω-dithiols, initiated by peroxides, is presented. The telechelic dithiols employed were prepared from nonconjugated dienes and a commercially available dithiol, or by esterification of adipic acid with 2-mercaptoethanol. From these dithiols, the diols were selectively obtained in high yields. Such α, ω-dihydroxylated compounds were characterized by both ¹H and ¹³C NMR spectroscopy. The diol which exhibits the ester functions shows excellent solubility in common organic solvents contrarily to the other ones. The physical properties (T_g, T_m and decomposition temperatures) of these diols were compared and it is noted that the thermostability of these monodispersed telechelic diols is much better than those of the polydispersed commercially available ones such as poly(ethylene glycol)s or poly(tetramethylene glycol)s.     

Adjunct effect of loratadine in the treatment of acute sinusitis in patients with allergic rhinitis

H₁-blockers are often added to the standard treatment of acute sinusitis, but this is not supported by a controlled study. A multicentric, randomized, double-blind, placebo-controlled, parallel-group study was done in 139 allergic patients (15–65 years) to assess the adjunct efficacy of loratadine in acute exacerbation of rhinosinusitis. Sinusitis was diagnosed by symptoms and confirmed by rhinoscopy and sinus radiograph. Allergy was characterized by skin tests, RAST, and history. Patients were treated with antibiotics (14 days), oral corticosteroids (10 days), and loratadine (10 mg OD) or placebo (28 days). Treatment efficacy was assessed over 28 days by symptom scores quoted daily by patients. Physicians also rated total symptom scores at entry and at day 28. At entry, both groups had similar symptoms. Placebo-treated patients improved significantly, but patients who received loratadine had a significantly greater improvement in sneezing ( P =0.003) after 14 days, and in nasal obstruction ( P =0.002) after 28 days. Physicians found that patients receiving loratadine were significantly improved compared to placebo patients ( P =0. 0125). Loratadine in addition to standard therapy was found to improve the control of some symptoms of sinusitis.     

Release of platelet-activating factor (PAF-acether) and arachidonic acid metabolites from alveolar macrophages

Human, monkey and rat alveolar macrophages (AM) release PAF-acether in a dose-dependent fashion in the presence of 1 to 5 g/ml ionophore A 23187 (2.5 pmol of PAF-acether from 2.5×10⁵ cells) but not in the presence of zymosan. Arachidonic acid (AA) metabolites released from AM from these species were studied. Thromboxane A₂ TxA₂)—detected by its action on rabbit arteries—was released from human, monkey and rat AM upon addition of 0.5 mM AA. This release was inhibited by aspirin and indomethacin. Lipoxygenase and cyclooxygenase AA metabolites from rat AM were identified using high efficiency glass capillary column gas chromatography coupled to mass spectrometry. The cyclooxygenase metabolites PGF₂, E₂ and D₂ and TxB₂ were identified. The lipoxygenase-dependent AA metabolites were explored using aspirin-pretreated AM. Only 12 HETE was found.These data indicate that AM secrete several substances with bronchoconstrictive activity: PGF₂, D₂, TxA₂ and PAF-acether. Therefore an active role of AM in human and experimental bronchoconstriction must be considered.     

Veränderungen der Serum-Antiotensinogen-Konzentration bei akuter Hepatitis und Lebercirrhosen

Zusammenfassung Die Angiotensinogen-Konzentration im Serum ist in der akuten und Abheil-Phase der Hepatitis (n=16) auf durchschnittlich 72–81% der Norm herabgesetzt. Bei 19 kompensierten und 10 dekompensierten Lebercirrhosen findet sich eine Substratverminderung auf 50%. Korrelationsstatistisch ist ein Zusammenhang zum Serum-Bilirubin, Albumin und Gesamtprotein sowie zur Transaminase-Aktivität weder für die Hepatitis- noch für die Cirrhose-Gruppe nachweisbar. Ebenso ergibt sich bei Lebercirrhosen keine statistisch gesicherte reziproke Abhängigkeit zwischen Serum-Renin-Aktivität und Angiotensinogen-Spiegel. Auch bei hochgradiger Funktionseinschränkung ist die Leber noch zur Substratsynthese befähigt. Ein totaler Schwund ist selten.     

HLA Antigens in 16 Families with Xeroderma Pigmentosum

Xeroderma pigmentosum is an autosomal recessive disease. HLA-A and -B typing was performed on peripheral blood lymphocytes and platelets. Sixteen Tunisian families were typed with 37 patients and 108 relatives. Genetic transmission of the disease and of the HLA system seemed to be independent in this study. Comparison of HLA gene frequencies between (unrelated) parents of patients and a control population showed no difference, proving that there is no clear association in populations between deleterious XP genes and a particular HLA gene. However, an excess of identical HLA among pairs of diseased siblings would suggest that the disease is polymorphic and a form of the XP could be linked to HLA.     

Complete sparing of high-contrast color input to motion perception in cortical color blindness

It is widely held that color and motion are processed by separate parallel pathways in the visual system, but this view is difficult to reconcile with the fact that motion can be detected in equiluminant stimuli that are defined by color alone. To examine the relationship between color and motion, we tested three patients who had lost their color vision following cortical damage (central achromatopsia). Despite their profound loss in the subjective experience of color and their inability to detect the motion of faint colors, all three subjects showed surprisingly strong responses to high-contrast, moving color stimuli--equal in all respects to the performance of subjects with normal color vision. The pathway from opponent-color detectors in the retina to the motion analysis areas must therefore be independent of the damaged color centers in the occipitotemporal area. It is probably also independent of the motion analysis area MT/V5, because the contribution of color to motion detection in these patients is much stronger than the color response of monkey area MT.     

Skinfold thickness versus isotope dilution for body fat assessment during simulated microgravity: results from three bed-rest campaigns in men and women with and without countermeasures

Because body composition is altered during head-down bed rest (HDBR), body mass can not be used as an index of energy balance. Consequently diet allowances should not be based on body mass evolution but on fat mass changes. Though criticized, skinfold thickness (ST) is the costless, easiest and fastest method to use for such an objective. The aim of this study was to compare the percentage of body fat (%BF) estimated by ST with the isotope dilution of H₂¹⁸O. We compiled data from three HDBR campaigns, one on women (n=8) in November 1998 and two on the same men (n=8) in December 1997 (without countermeasure) and January 1998 (with thigh-cuffs countermeasure), according to a crossover design. Body composition was assessed before and after 6 days of HDBR. %BF was derived from the biceps, triceps, sub-scapular and sup-iliac ST according to Durnin and Wormersly (1974). Fat-free mass was measured on the same day by H₂¹⁸O dilution and fat mass was calculated by the difference with body mass and expressed as a percentage. Based on precision tests, the minimum measurable change by ST was 1.1%BF for single measurement point. Both intercepts (F _4,30=0.89, P=0.45) and slopes (F _4,30=0.74; P=0.57) of the ST versus dilution relationships were not affected by the periods (December vs January), experimental conditions (control vs HDBR vs HDBR + thigh cuffs) or sex allowing the derivation of a common relationship %BF_st=0.94 × %BF_dil (F _1,47=97.9, P<0.0001; non-significant intercept excluded) with a bias between methods of −1.7±2.0 %BF (95% CI: −5.8, 2.4 %BF). ST can be used to measure %BF during HDBR provided great care is placed on training and changes are higher than 1.1 %BF. If the method can be applied for in-flight energy balance monitoring given the high observed energy deficit, a tight monitoring of the individual nutritional status as needed during simulation appears, however, dubious based on this solely method.     

Lamellar cells of sensory receptors and perineural cells of nerve endings of pig skin contain cytokeratins

Summary The lamellar cells of the sensory corpuscles of the pig dermis must be considered to be epithelial cells as they contain cytokeratins. The cytokeratins detected are similar to those found in simple epithelia. Moreover, lamellar cells are embedded in an extracellular matrix reminiscent of the basement membrane of epithelium since it contains laminin and collagen IV. The perineural cells surrounding the nerves of pig dermis present the same features.These results suggest that lamellar cells and perineural cells have the same origin. The nature of the lamellar and perineural cells of the rabbit or human dermis is not as clear since cytokeratins were not detected in those cells. These results, together with recent observations on Merkel cells, may indicate that epithelio-neuronal junctions are a general feature of cutaneous sensory receptors.