Mechanistic insights into hydride transfer for catalytic hydrogenation of CO(2) with cobalt complexes.

The catalytic hydrogenation of CO2 to formate by Co(dmpe)2H can proceed via direct hydride transfer or via CO2 coordination to Co followed by reductive elimination of formate. The different nature of the rate-determining step in the two mechanisms may provide new insights into designing catalysts with improved performance.

A protective effect of the Mediterranean diet for cutaneous melanoma.

BACKGROUND: Many studies have investigated the Mediterranean diet as a risk factor for cancer, none of which has included cutaneous melanoma. The latter is usually fatal, rendering knowledge about prevention extremely important. We assessed the role of some food components of the Mediterranean diet and cutaneous melanoma. METHODS: A hospital-based case-control study was conducted in the inpatient wards of IDI-San Carlo Rome, Italy including 304 incident cases of cutaneous melanoma and 305 controls, frequency matched to cases. Information on socio-demographic characteristics, medical history, smoking, sun exposure, pigmentary characteristics and diet was collected. Logistic regression was the method used to estimated odds ratio and 95% CIs. RESULTS: After careful control for several sun exposure and pigmentary characteristics, we found a protective effect for weekly consumption of fish (OR, 0.65, 95%CI = 0.43-0.97), shellfish (OR, 0.53, 95%CI = 0.31-0.89), fish rich in n-3 fatty acids (OR, 0.52, 95%CI = 0.34-0.78), daily tea drinking (OR, 0.42, 95%CI, 0.18-0.95; P(trend) = 0.025) and high consumption of vegetables (OR, 0.50, 95%CI = 0.31-0.80, P(trend) = 0.005) in particular carrots, cruciferous and leafy vegetables and fruits (OR, 0.54, 95%CI =0.33-0.86, P(trend) = 0.013), in particular citrus fruits. No association was found for alcohol consumption and any other food items. CONCLUSION: Overall, our findings suggest that some dietary factors present in the Mediterranean diet might protect from cutaneous melanoma.

Impaired postural control in patients affected by tension-type headache.

Sixteen subjects, affected by chronic tension-type headache (TTH) accordingly to the International Headache Society Classification (1988) criteria, in presence of tenderness in pericranial muscles,with a mean age of 37+/-11.8 years, and ten healthy volunteer subjects, age and sex matched, were submitted to postural analysis by Static Posturography (S.Ve.P. Amplaid). Aim of the study was to evaluate whether patients with TTH have disturbed postural control, as compared to normal subjects. Postural analysis considered all posturographic variables but focused on spectral frequency analysis of body sway. In both open (OE) and closed eyes (CE) condition, spectral frequency analysis showed a significantly increased body sway at low (OE= p < or = 0.01; CE= p < or = 0.01) and middle (OE= p < or = 0.01; CE= p < or = 0.01) frequencies on the antero-posterior (y) plane and at low frequencies (OE= p < or = 0.05; CE= p < or = 0.05) on the lateral (x) plane. Statistical analysis was performed using the Student's t test for unpaired data, p value 0.05 defined significant. The proprioceptive input seems to be predominant at middle and high frequencies in maintaining posture, our results seem then to suggest a proprioceptive disturbance in TTH patients. The disturbance is likely related to chronic pericranial muscle contraction and tenderness. Posturography and spectral analysis may help not only in the diagnosis of a postural disturbance but even more in the follow-up of TTH patients, during and after a medical and/or a rehabilitative treatment.

Psychosomatic factors in first-onset alopecia areata.

Although the onset of alopecia areata has often been anecdotally linked with emotional stress, findings from the few controlled studies have not been univocal. The authors compared outpatients experiencing a recent onset of alopecia areata (N=21) with outpatients affected by skin conditions commonly believed as having a low psychosomatic component (N=102). Participants were administered Paykel's Interview for Recent Life Events, the Experiences in Close Relationships scale, the 20-item Toronto Alexithymia Scale, and the Multidimensional Scale of Perceived Social Support. Multiple logistic regression was used to control for age and gender. The total number of recent life events (last 12 months) was not different between the alopecia patients and the comparison subjects. Also, the alopecia patients and the comparison subjects did not differ in terms of the number of undesirable or major events. The comparison subjects even experienced a greater number of uncontrollable events. Alopecia areata tended to be associated with high avoidance in attachment relationships, high alexithymic characteristics, and poor social support. The results suggest that personality characteristics might modulate individual susceptibility to alopecia areata.

Stressful life events, social support, attachment security and alexithymia in vitiligo. A case-control study.

BACKGROUND: It has often been suggested that stress might trigger vitiligo. However, only one study supported this hypothesis, and no study explored the role of other personality or social factors. METHODS: Out-patients experiencing a recent onset or exacerbation of vitiligo (n = 31) were compared with out-patients with skin conditions in which psychosomatic factors are commonly were regarded as negligible (n = 116). Stressful events during the last 12 months were assessed with Paykel's Interview for Recent Life Events. Attachment style, alexithymia and social support were assessed with the 'Experiences in Close Relationships' questionnaire, the Toronto Alexithymia Scale (TAS-20), and the Multidimensional Scale of Perceived Social Support, respectively. RESULTS: Cases and controls did not differ regarding the total number of events and the number of undesirable, uncontrollable or major events. Three or more uncontrollable events had occurred more frequently among cases than controls. Perceived social support was lower in cases than in controls. Cases scored higher than controls on anxious attachment, tended towards higher scores on avoidant attachment and were classified more often as insecure. Cases scored higher than controls on the TAS-20 and were classified more often as alexithymic or borderline alexithymic. The occurrence of many uncontrollable events, alexithymia and anxious attachment were associated with vitiligo also in multiple logistic regression analysis. CONCLUSIONS: These findings suggest that vulnerability to vitiligo is not increased by stressful events, except for many uncontrollable events. Alexithymia, insecure attachment and poor social support appear to increase susceptibility to vitiligo, possibly through deficits in emotion regulation or reduced ability to cope effectively with stress.

Radical and non-radical mechanisms for alkane oxidations by hydrogen peroxide-trifluoroacetic acid.

The oxidation of cyclohexane by the H2O2-trifluoroacetic acid system is revisited. Consistent with a previous report (Deno, N.; Messer, L. A. Chem. Comm. 1976, 1051), cyclohexanol forms initially but then esterifies to cyclohexyl trifluoroacetate. Small amounts of trans-1,2-cyclohexadiyl bis-(trifluoroacetate) also form. Although these products form irrespective of the presence or absence of O2, dual mechanisms are shown to operate. In the absence of O2, the dominant mechanism is a radical chain reaction that is propagated by CF3. abstracting H from C6H12 and SH2 displacement of C6H11. on CF3CO2OH. The intermediacy of C6H11. and CF3. is inferred from production of CHF3 and CO2 along with cyclohexyl trifluoroacetate, or CDF3 when cyclohexane-d12 is used. In the presence of O2, fluoroform and CO2 are suppressed, the reaction rate slows, and the rate law approaches second order (first order in peracid and in C6H12). Trapping of cyclohexyl radicals by quinoxaline is inefficient except at elevated (approximately 75 degrees C) temperatures. Fluoroform and CO2, telltale evidence for the chain pathway, were not produced when quinoxaline was present in room temperature reactions. These observations suggest that a parallel, nonfree radical, oxenoid insertion mechanism dominates when O2 is present. A pathway is discussed in which a biradicaloid-zwiterionic transition state is attained by hydrogen transfer from alkane to peroxide oxygen with synchronous O-O bond scission.

Comparison of pharmacological treatment versus acupuncture treatment for migraine without aura--analysis of socio-medical parameters.

This study was carried out in 120 patients affected by migraine without aura, treated in 4 public health centers and randomly divided into acupuncture group (AG) and conventional drug therapy group (CDTG). The evaluation of clinical results was made 6 and 12 months after the beginning of treatment and was worked out as well according to socio-medical parameters. Acupuncture was applied to the following points: Touwei (ST 8), Xuanlu (GB 5), Fengchi (GB 20), Dazhui (GV 14), Lieque (LU 7), treated with the reducing method. In AG, the figure scoring the entity and frequency of migraine attacks drops from 9,823 before treatment to 1,990 6 months after and 1,590 12 months after; while in CDTG, it drops from 8,405 before treatment to 3,927 6 months after and 3,084 12 months after. In AG, the total absence from work amounted to 1,120 working days/year, with a total cost (private + social costs) of 186,677,000 Italian liras. In CDTG, the absence from work amounted to 1,404 working days/year, with a total cost of 266,614,000 Italian liras. If we consider that in Italy the patients affected by migraine without aura are around 800,000, and that acupuncture therapy is able to save 1,332,000 Italian liras on the total average cost supported for every single patient, the application of acupuncture in the treatment of migraine without aura would allow a saving of the health expenses in Italy of over 1,000 billion liras.

Pain therapy in elderly cancer patients.

In most (65-80%) cancer patients at an advanced stage of illness we find significant, invalidating symptoms of pain. Cancer pain is a complex pain (with a nociceptive, neuropathic and deafferentation component), which requires a multidisciplinary approach (surgery, radiochemotherapy, and pain therapy). Pain therapy has various pharmacological strategies at its disposal (opiates, anti-inflammatory and adjuvant drugs) together with modulation and neurodestructive techniques, which must be applied taking account of both the stage of the disease and the pain intensity. In elderly patients, a careful, tailored management of pharmacological therapy is required. In older age, personality disorders are also to be found (anxiety, depression, hypocondria and feeling of abandonment), which make therapy more complex and varied. Knowledge of these problems will, however, make it possible to control cancer pain in elderly patients to the best possible effect and improve the quality of life in the advanced and terminal stages.

Polymerase chain reaction and reverse cross blot hybridization assay for detection of mycobacterial DNA in lupus vulgaris.

For 5 years, an 83-year-old man had been suffering from slightly itchy erythematous plaques with clearcut margins, located on his left thigh and on his right arm; in addition, on his right auricle there was an erythematous patch with yellowish shadings that had appeared about 3 years before and had progressively spread to the temporal-zygomatic region, the chin and the mandibular arch. These lesions were strongly suggestive of lupus vulgaris; however the conventional bacteriological examinations performed on the biopsy specimen from lesional skin were negative. A diagnosis of lupus vulgaris was achieved through the detection of the 16S rRNA gene of Mycobacterium tuberculosis in a skin biopsy of the patient by means of a polymerase chain reaction followed by a reverse cross blot hybridization, a method which allows the identification of different mycobacterial species in a single hybridization procedure.

Predicting in-hospital mortality after hip fracture in elderly patients.

Ninety-seven patients aged 88 +/- 4 years (range, 80-97 years) (study group), and 74 aged 75 +/- 3 years (range, 70-79 years) (control group), were prospectively studied to investigate whether basic medical variables can predict in-hospital mortality in very old patients undergoing hip surgery because of femoral fracture. Mortality was 16.5% and 6.7% in the study and control groups, respectively (p = 0.054). In the study group, mortality was significantly correlated with age (p < 0.01), venous disorders (p < 0.05), malnutrition (p < 0.0001), duration of surgery (p < 0.006), and postoperative noninfectious complications (p < 0.005). In the control group, age was the only significant correlate of mortality (p < 0.005). After exclusion of surgery-related variables, the logistic regression analysis confirmed the predictive role of venous disorders (odds ratio = 2.04, confidence limits = 1.09-3.79) and malnutrition (odds ratio = 6.01, confidence limits = 1.85-19.47) but not of age in the study group. However, the goodness-of-fit test showed that the statistical model did not fit the data adequately. We conclude that in-hospital mortality after hip surgery in the very old cannot be predicted on the basis of underlying medical conditions alone.

[Anesthesia for laparoscopic cholecystectomy: the use of nitrous oxide in the anesthetic mixture]. / Anestesia per colecistectomia laparoscopica: utilizzo del protossido d'azoto nella miscela anestetica.

A study carried out on 44 patients undergoing laparoscopic cholecystectomy was started in order to evaluate if nitrous oxide is or not contraindicated. The patients were divided in two groups of 22 subjects receiving or not nitrous oxide in the anaesthetic mixture. All the patients received the same preanaesthetic medication (diazepam and atrophine), thiopental and fentanyl as induction drugs, vecuronium as muscle relaxant and isoflurane for maintenance of anaesthesia. Bowel distension, technical difficulty, incidence of postoperative nausea and vomiting were examined. Our conclusions were that nitrous oxide has no clinically deleterious effects during laparoscopic cholecystectomy.

[An unusual cause of obstruction of the anesthesia circuit ]. / Una inusuale causa di ostruzione del circuito di anestesia.

The authors report an unusual accident, uneventful for the patient, due to the mobilization of a foreign body (a piece of tape) inside the anaesthesia circuit, following Emergency Oxygen administration. The accident dynamics and the safety of anaesthesia equipment are discussed.