Thermoanalytical and spectroscopic characterisation of solid-state retinoic acid

Thermoanalytical (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TG/FTIR)) and spectroscopic (X-ray diffraction (XRD), ultraviolet-visible (UV-Vis), mass spectrometry (MS) and Fourier transform infrared diffuse reflectance (DRIFT) measurements have been used to characterise solid-state retinoic acid (RA) from a chemico-physical point of view. Between 130 and 160 degrees C, a phase transition takes place that does not correspond to the transition between the known monoclinic and triclinic phases (DSC and XRD evidence). By annealing in air (in the 130-160 degrees C temperature range and for different times), an exothermic oxidative degradation occurs that, depending on the thermal treatment, competes with the mentioned phase transition (TGA evidence). Spectroscopic techniques (UV-Vis, MS and DRIFT) allow one to conclude that the new solid phase is still constituted by retinoic acid with a different orientation of the side chain. Finally, RA does not undergo stable melting: the fragmentation patterns, both in air and in nitrogen, have been examined by TG/FTIR.

Functional characterization of an ammonium transporter gene from Lotus japonicus

NH(4)(+) is the main product of symbiotic nitrogen fixation and the external concentration of combined nitrogen plays a key regulatory role in all the different step of plant-rhizobia interaction. We report the cloning and characterization of the first member of the ammonium transporter family, LjAMT1;1 from a leguminous plant, Lotus japonicus. Sequence analysis reveals a close relationship to plant transporters of the AMT1 family. The wild type and two mutated versions of LjAMT1;1 were expressed and functionally characterized in yeast. LjAMT1;1 is transcribed in roots, leaves and nodules of L. japonicus plants grown under low nitrogen conditions, consistent with a role in uptake of NH(4)(+) by the plant cells.

First search for gravitational wave bursts with a network of detectors

We report the initial results from a search for bursts of gravitational radiation by a network of five cryogenic resonant detectors during 1997 and 1998. This is the first significant search with more than two detectors observing simultaneously. No gravitational wave burst was detected. The false alarm rate was lower than 1 per 10(4) yr when three or more detectors were operating simultaneously. The typical threshold was H approximately 4x10(-21) Hz-1 on the Fourier component at approximately 10(3) Hz of the gravitational wave strain amplitude. New upper limits for amplitude and rate of gravitational wave bursts have been set.

Antihistamine terfenadine potentiates NMDA receptor-mediated calcium influx, oxygen radical formation, and neuronal death

We previously reported that the histamine H1 receptor antagonist terfenadine enhances the excitotoxic response to N-methyl-D-aspartate (NMDA) receptor agonists in cerebellar neurons. Here we investigated whether this unexpected action of terfenadine relates to its antihistamine activity, and which specific events in the signal cascade coupled to NMDA receptors are affected by terfenadine. Low concentrations of NMDA (100 microM) or glutamate (15 microM) that were only slightly (<20%) toxic when added alone, caused extensive cell death in cultures pre-exposed to terfenadine (5 microM) for 5 h. Terfenadine potentiation of NMDA receptor response was mimicked by other H1 antagonists, including chlorpheniramine (25 microM), oxatomide (20 microM), and triprolidine (50 microM), was prevented by histamine (1 mM), and did not require RNA synthesis. Terfenadine increased NMDA-mediated intracellular calcium and cGMP synthesis by approximately 2.4 and 4 fold respectively. NMDA receptor-induced cell death in terfenadine-treated neurons was associated with a massive production of hydrogen peroxides, and was significantly inhibited by the application of either (+)-alpha-tocopherol (200 microM) or the endogenous antioxidant melatonin (200 microM) 15 min before or up to 30 min after receptor stimulation. This operational time window suggests that an enduring production of reactive oxygen species is critical for terfenadine-induced NMDA receptor-mediated neurodegeneration, and strengthens the importance of antioxidants for the treatment of excitotoxic injury. Our results also provide direct evidence for antihistamine drugs enhancing the transduction signaling activated by NMDA receptors in cerebellar neurons.

Analysis of deaths due to injury in Milano: preliminary results

We reviewed all trauma deaths occurring in the urban area of Milan during one year. Autopsy reports were cross-referenced with pre- and in-hospital records and the Injury Severity Score was calculated by a senior surgeon. Causes of deaths were defined as central nervous system injury (CNS), hemorrhage (HEM), combined central nervous system injury and hemorrhage (CNS + HEM), and burns (BURN). Places of death were considered the scene (DOS), during transportation (DOA), the emergency room (DER), and hospital. Two multidisciplinary commissions reviewed patient reports and deaths were judged non-preventable, possibly preventable or frankly preventable, using the unanimous decision rule. The TRISS method was used to calculate the probability of survival for in-hospital deaths. Overall trauma deaths were 255 with 78.04% blunt and 16.08% penetrating traumas. Burns accounted for 5.88%. CNS and CNS + HEM caused 171 (67.05%) deaths. DOS were 91, DOA 48, DER 34, and in-hospital deaths 33. Victims found dead (49 individuals) were excluded from further analysis. The commissions classified 56.31% of deaths as non-preventable, 32.03% as possibly preventable and 11.65% as frankly preventable. The Injury Severity Score decreased from DOS to in-hospital deaths (p < 0.05). The preventability rate was higher for in-hospital deaths (p < 0.05). The results of this study suggest that the development of a tiered trauma system in Milan is mandatory.

A clinical trial of intravenous vinorelbine tartrate plus tamoxifen in the treatment of patients with advanced malignant melanoma

BACKGROUND

The aim of the current trial was to assess the efficacy and toxicity of weekly intravenous vinorelbine tartrate with daily oral tamoxifen in the treatment of patients with advanced or metastatic malignant melanoma.

METHODS

Thirty-one patients were treated with vinorelbine tartrate, 30 mg/m(2) intravenously, weekly every 13 weeks and then every 2 weeks thereafter until progression of disease or severity of toxicity warranted discontinuation. Tamoxifen, 10 mg orally, twice a day was administered daily starting on Day 1 of chemotherapy with vinorelbine tartrate. Thirty patients had cutaneous melanoma with metastases and 1 patient had ocular melanoma with metastases. Eight patients had received prior chemotherapy.

RESULTS

Of the 30 evaluable patients with cutaneous melanoma, 6 achieved a partial response, for an overall response rate of 20% (95% confidence interval, 7-38%). There was no response in the patient with ocular melanoma. Major sites of response include the adrenal gland, lung, tonsil, and cutaneous/subcutaneous tissues. Three patients had a prolonged duration of response lasting > or = 12 months. Side effects generally were mild and tolerable. Grade 3 or 4 hematologic toxicity occurred in 26% and 13% of patients, respectively. Nonhematologic toxicity included mild fatigue, paresthesia, and local arm discomfort from infusion.

CONCLUSIONS

Weekly intravenous vinorelbine tartrate plus daily oral tamoxifen appears to be active in the treatment of patients with malignant melanoma. Further clinical trials in malignant melanoma patients treated with vinorelbine tartrate and tamoxifen appear warranted.

Physico-chemical characterization of a novel tricyclic beta-lactam antibiotic

GV118819X, a novel tricyclic beta-lactam antibiotic of GlaxoWellcome, is a racemic mixture of two diastereoisomers, A and B. Of the two diastereoisomers, only A is available as a pure compound. By analyzing mixtures of GV118819X and A, a partial phase diagram is constructed, which indicates the presence of a eutectic when the A fraction is approximately 39%. Moreover, the melting enthalpies of the eutectic mixture and of diastereoisomer B can be estimated. With the exception of the pure A form, all mixtures undergo important modifications in morphology and microstructure as a consequence of thermal treatments, which induce melting/amorphization of the eutectic, and crystallization of the A form. Analyses of the sieved fractions of GV118819X demonstrate that it consists of acicular crystals of different composition, with the larger crystals having a larger A fraction than the smaller ones. Grinding causes melting/amorphization of the eutectic and, following hours-long treatments, the formation of a substantial fraction of submicron particles with unusually low melting temperatures.

Cosmic rays observed by the resonant gravitational wave detector NAUTILUS

The passage of cosmic rays has been observed to excite mechanical vibrations in the resonant gravitational wave detector NAUTILUS operating at temperature of 100 mK. A very significant correlation (more than 10 standard deviations) is found.

Coronary artery vasomotion and post-stenotic coronary artery blood flow after intracoronary lacidipine in patients with ischaemic heart disease: a pilot study

BACKGROUND

The calcium antagonist lacidipine has been shown to be highly vasoselective and to improve myocardial perfusion in hypertensive patients. However, its effects on coronary artery vasomotility and on post-stenotic coronary flow reserve in patients with atherosclerotic heart disease are unknown.

OBJECTIVES

This study was designed to investigate the acute direct effects of repeated infusions of lacidipine on epicardial coronary artery vasomotion and on post-stenotic coronary artery blood flow in patients with stable angina pectoris and angiographic evidence of coronary heart disease.

METHODS

In 8 patients with stable angina and moderate to severe stenosis of the left coronary artery, measurements of epicardial dimensions (quantitative angiography) and of coronary blood flow (Doppler guidewire) distal to a stenosis were performed at baseline and after 3 repeated intracoronary boluses of 12 microg of lacidipine. Results were compared with those obtained after 10 mg of intracoronary papaverine.

RESULTS

The intracoronary administration of lacidipine was well tolerated, without any adverse effects. Lacidipine significantly increased the minimal luminal diameter of the lesion (peak relative increase of 43.7%), without significant changes in heart rate and systolic aortic pressure. Intracoronary lacidipine caused a dose-dependent increase in coronary flow reserve. Maximal vasodilatory effects were equivalent to those obtained with intracoronary papaverine.

CONCLUSIONS

These results suggest that lacidipine acts directly as a potent vasodilator in stenotic epicardial vessels and improves myocardial perfusion distal to a moderately severe stenosis in patients with stable angina.

[Severe pelvic injuries: indications and techniques of skeletal fixation]

The aim of this work is to assess the role of immediate Hoffmann's external fixation frame and delayed posterior internal fixation in the management of severe pelvic injuries. We have also analysed the role of selective arteriography and embolization for controlling pelvic fractures hemorrhage and the relationship between embolization and external fixation in the management of severe bleeding. We reviewed 112 patients with severe pelvic injuries admitted to our hospital from 1986 to 1998 (71 males, 41 females). The average age was 39.8 years, mean ISS 31.2. Unstable pelvic ring fracture was present in 59 (52.6%) patients at admission in the emergency room: hemorrhagic shock in 43 patients (38.3%). Fourteen (12.5%) patients died. Eight deaths (57%) were directly caused by hemorrhagic shock, two secondary to major caval lesion, three brain lesions and two respiratory failure. The last patient died secondary to MOF. Twenty-three patients (20.5%) with unstable fracture underwent pelvic fracture ring fixation surgery: eleven (9.8%) Hoffmann's anterior external fixation frame (hemorrhage control in all patients) and eight (7.1%) delayed internal posterior fixation. Six (5.3%) patients underwent arteriography and embolization: hemorrhage was stopped in all cases and no patient died in this group.

Update on mechanical revascularization in acute myocardial infarction: which role and when?

Mechanical revascularization in the acute myocardial infarction by primary angioplasty has several advantages over thrombolytic therapy. The short-term patency rates of the infarct-related artery range from 95 to 99% and a normal flow is achieved in more than 90% of the cases. This prompt and effective reperfusion is probably responsible for the improved prognosis with primary angioplasty. The better outcome after primary angioplasty is observed both in low- and in high-risk patients, in all ages and in patients presenting late (>6 h) after the chest pain. Pooled analysis of randomized studies, show that primary angioplasty as compared to thrombolysis, has a lower incidence of death, stroke and reinfarction. Additional advantages of primary PTCA include the possibility of reperfusion in patients in whom lysis is contraindicated or less effective (e.g. patients in cardiogenic shock, or with prior coronary artery bypass surgery) and the ability to provide prognostic information helpful in the patient triage. Thus, primary PTCA results in better outcome than thrombolysis when performed in centers with success rates comparable to those achieved in the randomized trials. Further studies are still needed to assess its long-term efficacy. Several randomized trials are underway to assess the role of stents and the use of more potent antiplatelet drugs, as the GPIIb/IIIa receptor blockers, in adjunct to balloon angioplasty in the treatment of acute myocardial infarction.

The epidemiology of multiple births

On the basis of MEDLINE and manual searches, we examined the main papers in the English literature regarding risk factors for spontaneous (i.e. not related to fertility drug use) multiple births. The constant frequency of monozygotic (MZ) pregnancies over time and in different geographical areas suggests that the determination of MZ twins is largely unchanged over time, and that a genetic mechanism may have a role. In contrast, temporal and geographical trends observed in dizygotic (DZ) pregnancies suggest that environmental factors play a role in determining this condition. At present, maternal age and hereditary components are the best-defined determinants for spontaneous multiple births.

Starvation in yeast increases non-adaptive mutation

The frequency of reversion in a histidine-requiring mutant of Saccharomyces cerevisiae increases about ten-fold in stationary cells during histidine starvation. Histidine starvation enhances a similar frequency of reversion in a tryptophan-requiring mutant. Starvation, therefore, enhances mutation frequencies in a non-adaptive manner. The base analogue 6-N-hydroxylaminopurine (HAP) added prior to plating on medium with limited histidine strongly increases reversion of the histidine mutant. HAP-induced reversion increases further in stationary starving cells with the same kinetics as that which increases spontaneous reversion. Adding HAP to the stationary starving cells does not produce any effect.

Detection of eosinophils in whole blood samples by flow cytometry

A flow cytometric method to detect and study human eosinophils in whole blood was established. Normal subjects and patients with various types of eosinophilia (hypereosinophilic syndromes, allergic diseases, dermatitis, Hodgkin's Disease, parasitosis) were studied. Whole blood samples were treated for 10 minutes at room temperature with a commercially available reagent (FACS Lysing Solution, Becton Dickinson) which acts both as a fixative and as a lysing agent. Eosinophils were identified as a granulocytic subpopulation with higher SSC and FSC properties. This cell population was characterized by evident autofluorescence and hypodiploid DNA features after propidium iodide staining. The purity of the eosinophil population sorted after electronic gating was close to 100%. A very significant correlation between eosinophil counting by our whole blood method and other two assays, namely routine automatic counting by the H*3 Bayer System and eosinophil detection by depolarized SSC, was obtained. The phagocytic properties of eosinophils were also studied by means of a commercially available diagnostic kit, thus demonstrating that our method is also suitable for the study of those granulocytic functions which can be evaluated by flow cytometry.

Fetal gallstones: sonographic and clinical observations

Fetal gallstones were visualized sonographically in two cases at 30 and 37 weeks' gestation; follow-up scans at 2 and 3 months, respectively, disclosed their spontaneous resolution. The hypotheses advanced to explain the formation of echogenic material in the fetal gallbladder are reviewed, and the clinical utility of postnatal long-term sonographic follow-up is stressed.

Pseudoreticulocytosis in a case of myelodysplastic syndrome

A patient with normocytic anemia and marked and persistent reticulocytosis is presented. Causes responsible for blood loss and hemolytic diseases were excluded and, after bone marrow examination, myelodysplastic syndrome (refractory anemia) was diagnosed. In vitro reticulocyte survival studies suggested that reticulocytosis was a consequence of delayed maturation of the reticulocytes. Pseudoreticulocytosis may be an unusual presentation of myelodysplastic syndromes, because only 4 patients with such a finding have previously been reported.

MRI in the study of distal primary myopathopies and of muscular alterations due to peripheral neuropathies: possible diagnostic capacities of MR equipment with low intensity field (0.2 T) dedicated to peripheral limbs

The purpose of this work was to investigate whether or not an magnetic resonance imaging (MRI) equipment with a low field intensity (0.2 T) used in the study of muscular alterations can diagnose primary or secondary myopathies, due to peripheral neuropathies. In this study the peripheral areas of all patients were examined. A total of 40 patients (23 males and 17 females) were tested. Their age ranged from 10 to 78 years age (mean age 40.8, SD +/- 19,45 years). The group includes 23 patients: 18 with Stainert Myotonic Distrophy, 5 were myositic, and the remaining 17 had peropheral neuropathies. Every patient received a clinic examination, followed by EMG and MRI. The MRI study was done with a system dedicated to the study of limbs (Artoscan, Esaote Biomedica) that used a 0.2 T permanent magnet. Spin-echo T1, T2-weighted, multiple-echo, and STIR sequences were used. A good correspondence was found between clinical and MRI data. Specifically, in the group of 23 myopathies, Sperman's index was found to be 0.80 in its correlation between the clinical examination and MRI; in the group of 17 myopathies it was found to be 0.63. A discrepancy was found among clinical examination, EMG, and MRI in patients with neuropathies who were showing a lack of myelin and mixed ones. The T2-weighted and STIR sequences had great sensitivity in showing initial changes in the muscles. The SE T1-weighted sequence was especially useful in detecting degeneration in the fibrous adipose tissue. The STIR sequence because of its high sensitivity and greater speed of response could be used instead of the SE T2 weighted particularly in the study of patients, who were noted to tolerate a prolonge period of scanning. However, because these sequences have a low signal noise ratio, they must always be associated with a SE sequence, whenever there would be need of a precise determination of the structures under study. The MRI low field intensity was also found to be a useful technique in screening familial groups having a great number of myotonic distrophies. It can have a great clinical role in revealing muscular alterations, even in asymptomatic patients.