IMS study of climate, altitude, temperature and vasomotor symptoms in the United Arab Emirates.

OBJECTIVE: To examine the relationships between temperature, season (summer versus winter), lifestyle, health, mood, beliefs, and experience of hot flushes and night sweats (HFNS), amongst mid-aged women living in the United Arab Emirates (UAE). METHODS: The UAE climate is hyper-arid, being a hot desert climate, with warm winters and hot summers. A total of 372 peri- and postmenopausal women, aged from 45 to 55 years, from urban UAE regions were included. Data were collected during both summer and winter months. Participants completed questionnaires eliciting information about sociodemographics, HFNS (prevalence, frequency and problem-rating), health and lifestyle (body mass index (BMI), diet, exercise), mood (Women's Health Questionnaire) and menopause attributions and beliefs (Menopause Representations Questionnaire). RESULTS: HFNS were currently being experienced by 46.5% of women, with an average weekly frequency of five and problem-rating of 5.7/10. Seasonal variation in temperature was not associated with prevalence, frequency or problem-rating. Hot flush prevalence was associated with poor health, life satisfaction, mood, employment, lower BMI and diet. Higher frequency was associated with higher BMI and more years since the last period. HFNS were more problematic mainly for women who reported lower life satisfaction and held more negative beliefs about the menopause. CONCLUSIONS: In this UAE study, temperature and seasonal temperature variation did not appear to influence HFNS-reporting, but health, life satisfaction, BMI, beliefs and lifestyle factors partially explained women's experiences of menopausal symptoms. A qualitative study might provide further information about the meanings of HFNS and menopause amongst UAE women.

An unusual association between oral sarcoma and bulbar palsy.

A 90 year old male presented with symptoms and signs of right lower cranial nerves palsy. A small mass was found on the right side at the back of his mouth. Light microscopy and histoimmunochemical studies of the biopsy of the mass showed an alveolar soft part sarcoma arising from the right myohyoid muscle. The unusual location and presentation of this rare tumor is discussed.

Intracranial tuberculoma.

Six patients with cerebral tuberculoma seen over a 2 year period are reported. Their clinical presentations, the result of investigations including radiological findings and their response to medical treatment are discussed and correlated with other reports in the literature. Eighty five percent of the patients were above the age of 30 years. All patients had negative past history of tuberculosis and both chest x-ray and erythrocyte sedimentation rate were within normal limits. Five patients presented with symptoms and signs of space occupying lesions but none had papilloedema. Two patients showed paradoxical enlargement or development of new tuberculous lesions during antituberculous therapy. The diagnosis was established by brain magnetic resonance imaging in 3 patients, and was further confirmed by brain biopsy in the other 3. All patients received antituberculous treatment for 12 months, except one who continued medication for 2 years. Four patients normalized with medical treatment. Intracranial tuberculoma must be included in the differential diagnosis of a space occupying lesion. Magnetic resonance imaging is a sensitive, non-invasive method to diagnose cerebral tuberculoma. Paradoxical enlargement or development of new tuberculomas during antituberculous therapy is a documented phenomenon which can be overcome by continuation of antituberculous treatment. Twelve months of antituberculous treatment is considered to be adequate to resolve intracranial tuberculoma.

An unusual association between oral sarcoma and bulbar palsy.

A 90 year old male presented with symptoms and signs of right lower cranial nerves palsy. A small mass was found on the right side at the back of his mouth. Light microscopy and histoimmunochemical studies of the biopsy of the mass showed an alveolar soft part sarcoma arising from the right myohyoid muscle. The unusual location and presentation of this rare tumor is discussed.

Intracranial tuberculoma.

Six patients with cerebral tuberculoma seen over a 2 year period are reported. Their clinical presentations, the result of investigations including radiological findings and their response to medical treatment are discussed and correlated with other reports in the literature. Eighty five percent of the patients were above the age of 30 years. All patients had negative past history of tuberculosis and both chest x-ray and erythrocyte sedimentation rate were within normal limits. Five patients presented with symptoms and signs of space occupying lesions but none had papilloedema. Two patients showed paradoxical enlargement or development of new tuberculous lesions during antituberculous therapy. The diagnosis was established by brain magnetic resonance imaging in 3 patients, and was further confirmed by brain biopsy in the other 3. All patients received antituberculous treatment for 12 months, except one who continued medication for 2 years. Four patients normalized with medical treatment. Intracranial tuberculoma must be included in the differential diagnosis of a space occupying lesion. Magnetic resonance imaging is a sensitive, non-invasive method to diagnose cerebral tuberculoma. Paradoxical enlargement or development of new tuberculomas during antituberculous therapy is a documented phenomenon which can be overcome by continuation of antituberculous treatment. Twelve months of antituberculous treatment is considered to be adequate to resolve intracranial tuberculoma.

Effect of physical constraints on the mechanisms of membrane fusion: bolaform lipid vesicles as model systems.

Bolaform lipid vesicles were used to study the effect of physical constraints on membrane fusion. In these vesicles the membrane is organized in a single monolayer, because of the presence of covalent bonds in its middle plane. Therefore, the formation of fusion intermediates is subject to higher energy barriers and greater geometrical constraints than is usual in bilayer membranes. Bolaform lipids were extracted from the thermophilic archaeon Sulfolobus solfataricus. These lipids can be divided into two classes, the monosubstituted molecules, in which one of the polar heads is glycerol, and the bisubstituted molecules, endowed with two complex polar heads. The fusion process in vesicles composed of different mixtures of monosubstituted/bisubstituted molecules was studied by means of fluorescence techniques. Ca2+ or poly(ethylene glycol) was employed as a fusogenic agent. We found that fusion of such constrained membranes is still possible, provided that molecules able to mediate a structural rearrangement of the membrane are present. This condition is fulfilled by monosubstituted molecules, which are able to partition the glycerol headgroup in the apolar moiety. In addition, the presence of traces (approximately 5%) of the monopolar compound diphytanylglycerol is an important factor for fusion to occur. On the contrary, vesicles formed by bisubstituted molecules are unable to fuse, irrespective of the fusogen employed.

Calcium-induced interaction and fusion of archaeobacterial lipid vesicles: a fluorescence study.

The lipids extracted from the membrane of the thermophilic archaeobacterium Sulfolobus solfataricus have an unusual bipolar structure. Each molecule is formed by two isoprenoid chains (with up to four cyclopentane groups per chain) ether-linked at both ends to glycerol or nonitol groups. These groups can be variably substituted, mainly with complex sugars. Fluorescence resonance energy transfer, aqueous contents mixing and calcein release assays were employed to assess whether bipolar lipid vesicles were able to undergo a calcium-induced fusion process. The possibility of getting fusion depends strongly on the phase behaviour of the lipids. With vesicles formed by the natural polar lipid extract (PLE), a mixture showing a complex polymorphic behaviour, the fusion process was observed above the temperature T congruent to 60 degrees C at 15 mM Ca2+. By contrast, no fusion was observed in vesicles of P2, a fraction displaying only the lamellar phase. A dramatic change of the fusion process was observed when egg PC or P2 was added to PLE. In this case only lipid mixing, but not a real fusion process occurred at T > or = 60 degrees C. The dependence of such a process on ionic conditions has also been studied. Additional experiments involving surface tension measurements on monolayers have been performed to assess the importance of a surface tension increase to get fusion. In contrast to other monopolar lipid systems, no detectable change in surface tension has been observed in our bipolar lipids even in cases in which the fusion process is present.

Molecular packing parameters of bipolar lipids.

The bipolar lipid fractions extracted from the thermophilic archaeobacterium Sulfolobus solfataricus have different chemical structures and geometrical shapes. The conditions which lead to the formation of vesicles were investigated in order to study the self-assembly of these molecules. Such conditions are fulfilled when an appropriate mixture of two different molecular species (both bipolar or bipolar and monopolar) is used. According to the theory introduced by Israelachvili and co-workers, lipid self-assembly results from the balance of interaction free energy, entropy and molecular geometry. We have shown that this theory can be extended to bipolar lipids, in spite of their more complex nature, and the experimental results obtained combining 1H-NMR, light scattering and entrapped volume techniques closely match theoretical expectations. To carry out calculations, it was necessary to introduce hypotheses about the disposition of bipolar molecules in the vesicle membrane. These hypotheses have been tested indirectly by measuring the transport properties mediated by carriers or channels, whose transport mechanism can be considered to be a probe of the membrane structure.

Monopolar-bipolar lipid interactions in model membrane systems.

1H-NMR, dynamic light scattering and negative staining electron microscopy have been used to study the formation and physico-chemical properties of aqueous dispersions of mixtures of monopolar lipids extracted from Sulfolobus solfataricus. This microorganism is a thermophilic archaeobacterium growing optimally at about 85 degrees C and pH 3. The two hydrolytic fractions of the membrane complex lipids that have been studied are: the symmetric lipid glycerol dialkyl glycerol tetraether (GDGT) and the asymmetric lipid glycerol dialkyl nonitol tetraether (GDNT). Electron micrographs of pure and mixed GDNT and GDGT dispersions show the formation of complex structures. Only above a critical monopolar/bipolar lipid ratio, typical of the bipolar lipid, could closed structures be formed and good agreement was obtained in sizing with NMR, electron microscopy and dynamic light scattering. NMR spectra have been carried out at several temperatures from 25 degrees to 85 degrees C, to obtain information on the temperature-dependent structural, dynamic and permeability properties of the co-dispersed vesicles. The results are discussed in terms of the steric constraints and the chemico-physical interactions occurring among the different parts of the molecules and compared with previous studies performed with different physical techniques.