4,4'-, 5,5'-, and 6,6'-dimethyl-2,2'-bipyridyls: the structures, phase transitions, vibrations, and methyl group tunneling of their complexes with chloranilic acid.

The crystal and molecular structures of 4,4(')- and 6,6(')-dimethyl-2,2(')-bipyridyl complexes with 2,5-dichloro-3,6-dihydroxy-p-benzoquinone (chloranilic acid, CLA) have been determined and compared with those of the complex with the 5,5(')-derivative, which is known to possess interesting antiferroelectric properties. In the crystalline state, all three compounds form hydrogen bonded chains with N(+)-H···O(-) and O-H···N bridges on both sides of the bipyridyl constituent. The comparison of three derivatives indicates that the N(+)-H···O(-) hydrogen bonds are shortest for the 5,5(')-dimethyl complex. The 4,4(')- and 6,6(')-derivatives do not show any ferroelectric feature. The 6,6(')-one is, however, characterized by a continuous phase transition, revealed in the differential scanning calorimetry, dilatometric, and dielectric characteristics. The tunneling splitting measured by neutron backscattering in the energy range ±30 µeV for the neat dimethyl bipyridyls and their complexes with CLA indicates that the different splittings are primarily due to the crystal packing effect and that charge transfer between interacting compounds plays only a minor role.

The structure of diaminodurene and the dynamics of the methyl groups.

Diaminodurene crystallizes in the orthorhombic space group Pbca, with eight molecules in the unit cell. Four inequivalent methyl groups with different environments exist in a molecule. The amino groups are also different, which is well reflected in infrared spectra. Two tunneling modes are resolved at 23.7 and 7.0 microeV at 4.5 K. Their intensities are consistent with the presence of two further unresolved tunneling modes. Quasielastic spectra are composed of three Lorentzians of equal intensities. The two low activation energies and tunnel modes are modeled into consistent rotational potentials. The third activation energy and a librational band are used to guess the strength of the two stronger rotational potentials. The internal modes related to the torsional/librational vibrations mix with ring torsions in the range of 70-220 cm(-1). This way the tunnel modes couple to ring torsions whose energy determines the broadening of both tunnel bands. The calculations for free molecules yield mode frequencies a little bit lower than the experimental inelastic neutron scattering (INS) values. Application of theoretical methods elaborated for the crystalline state leads to a satisfactory consistency. It is also valid for bending modes of NH(2) groups, which in the solid state show much higher frequencies than in the gas phase, as expected.

WASP: (Write a Scientific Paper). Doctors in Star Trek - Correctly compassionate, caring Kantian Zampolit.

Doctors in Star Trek are vital and central characters, often crucial in helping their captains to reach command decisions. They are also interdisciplinarians, performing not only medical tasks but also any form of work related to all fields of biology. Furthermore, these doctors also carry out any required research that pertains to the biological sciences. It is perhaps this unique blend of skills, combined with a fundamental orientation towards humanism and compassion, that leads to their default position, de facto, if not de jure, as the crew's ethics officers, a role that they embrace with as much dedication and zeal as the former Soviet communist political officers/commissars (the Zampolit) did theirs. This paper will show that from the very inception of Star Trek, doctors strictly adhered to deontological tenets which lead them to actively influence command decisions that pertain not only to health, but also to any ethical decisions that may have to be taken by Starfleet officers. This portrayal of future doctors signals the wishes of contemporary audiences: that future doctors remain humane, compassionate and ethical guardian angels, and not only superb medics.

Low frequency internal modes of 1,2,4,5-tetramethylbenzene, tetramethylpyrazine and tetramethyl-1,4-benzoquinone INS, Raman, infrared and theoretical DFT studies.

The results of inelastic neutron scattering (INS), Raman and infrared (IR) studies on 1,2,4,5-tetramethylbenzene (durene), tetramethylpyrazine (TMP) and tetramethyl-1,4-benzoquinone (TMBQ) in the solid state are reported. The observed frequencies are analyzed on the basis of DFT calculations. The low frequency region, below 400 cm(-1), related to the torsional and bending out-of-plane vibrations of the CH(3) groups, is of particular interest. The detailed analysis is possible due to the simulation of the INS spectra by using the auntie-CLIMAX program. It is shown that the observed low frequency INS bands are dramatically shifted, compared to the calculated ones, towards higher frequencies. Although one cannot exclude deficiencies of theoretical methods as applied to low frequency modes, it seems more probable the interpretation based on an existence of non-conventional CH(...)pi, CH(...)N, CH(...)O hydrogen bonds formed by the methyl groups in crystalline phases.

Revascularization with percutaneous coronary intervention does not affect androgen status in males with chronic stable angina pectoris.

There is a clear association between low serum testosterone and coronary artery disease (CAD) in men. Hypotestosteronaemia is associated with accelerated atherosclerosis and a quarter of men with CAD are biochemically hypogonadal. Amongst those with CAD, hypotestosteronaemia is associated with increased mortality. Testosterone vasodilates coronary arteries, and exogenous testosterone reduces ischaemia. Whether hypotestosteronaemia is a cause or a consequence of CAD remains unanswered. The aim of this prospective observational study was to investigate whether coronary revascularization affected androgen status in men with stable angina pectoris. Twenty five men (mean age 62.7, SD 9.18) with angiographically significant CAD and symptomatic angina underwent full coronary revascularization by percutaneous coronary intervention. Androgen status and symptoms of angina, stress, depression and sexual function were assessed before, and at one and 6 months after the coronary revascularization. All patients underwent complete revascularization which was associated with a significant reduction in angina symptoms and ischaemia. No significant difference was seen in total testosterone (11.33 nmol/L baseline; 12.56, 1 month post; 13.04 at 6 months; p = 0.08). A significant and sustained rise in sex hormone-binding globulin was seen (33.99 nm/L baseline; 36.11 nm/L 1 month post PCI; 37.94 nm/L at 6 months; p = 0.03) Overall, there was no significant alteration in any other marker of androgen status including free testosterone or bioavailable testosterone. There was no change in symptoms of anxiety, depression or sexual function. Coronary revascularization has no sustained effect on androgen status. This supports the hypothesis that hypotestosteronaemia is not a consequence of angina pectoris or myocardial ischaemia.

Evidence for free radical generation after primary percutaneous transluminal coronary angioplasty recanalization in acute myocardial infarction.

In animal models, oxygen-derived free radicals have been found to be important mediators of reperfusion injury to ischemic but viable myocardium. However, in humans, there is no direct evidence of free radical production after the restoration of coronary artery patency in acute myocardial infarction. The purpose of this study was to quantitate and assess the time course of free radical production in coronary venous outflow in patients with acute myocardial infarction undergoing successful recanalization of the infarct-related artery by primary percutaneous transluminal coronary angioplasty (PTCA). Primary PTCA was performed in 17 patients with acute myocardial infarction of < 6 hours duration. Direct free radical production was assessed by coronary venous effluent blood sampling before PTCA and at timed intervals up to 24 hours (or 48 hours in 6 patients) after recanalization. All samples were added to the spin trapping agent alpha-phenyl N-tert butyl nitrone and analyzed by electron paramagnetic resonance spectroscopy. Vessel patency resulted in a sharp increase in free radical signal. Relative to the level before PTCA, the changes reached statistical significance after only 15 minutes (p < 0.05). Peak signals were observed between 1 1/2 and 3 1/2 hours (p < 0.001), then declined up to 5 hours. A second increase in signal level was detected between 18 and 24 hours despite no angiographic evidence of reocclusion. A gradual decline was observed after 24 hours. These findings provide the first direct and quantitative evidence of free radical production in the immediate postrecanalization phase after thrombotic occlusion of a major coronary artery in humans.

Reappraising the role of immediate intervention following thrombolytic recanalization in acute myocardial infarction.

Early studies indicated that after successful thrombolytic recanalization, adjunctive percutaneous transluminal coronary angioplasty (PTCA) was not appropriate, even when a significant residual stenosis was present. The aim of this study was to assess in-hospital clinical outcomes of patients with acute myocardial infarction (AMI) who underwent successful recanalization after thrombolytic therapy. The relation between repeat AMI/unstable angina and the severity of the stenosis, as well as other angiographic and clinical features was also examined. One hundred patients with AMI of <10 hours underwent coronary angiography 2 hours after receiving thrombolytic therapy. Salvage PTCA +/- stenting was performed if recanalization was unsuccessful (Thrombolysis In Myocardial Infarction [TIMI] trial grade 0 to 2), and no PTCA was undertaken if there was brisk anterograde flow (TIMI 3). Angiographic analysis was performed to assess the severity of the residual lesion, as well as the presence or absence of thrombus. Forty patients had unsuccessful recanalization, and of these, 36 underwent attempted PTCA. Of the 60 patients with TIMI 3 flow, 15 required repeat angiography and PTCA after repeat AMI (n = 13) or unstable angina (n = 2) within 5 days. Receiver-operating characteristic analysis indicated an optimum percent diameter stenosis predictor of 85% for repeat AMI/unstable angina. There was no additional relation to age, gender, time to thrombolysis, the infarct-related artery, or the presence of culprit lesion thrombus. After recanalization, a high-grade stenosis >85% is common (n = 25, 42.4%). This is associated with a 54% repeat AMI/unstable angina risk-a ninefold increase in the incidence of such events than in patients with lesions <85%. Thus, patients with narrowings >85% may benefit from early intervention rather than a conservative approach. Narrowings <85% have a 94% probability of no repeat AMI/unstable angina and do not require early intervention.

Anti-Co3 and severe hemolytic disease of the newborn.

Irregular antibodies have been described to cause hemolytic disease of the newborn of varying severity. A case of anti-Colton 3 causing moderate to severe hemolysis in the newborn in two pregnancies is described. Only two cases of hemolytic disease of the newborn have been previously described; these resulted in mild hemolysis. The management of the condition is reviewed in the light of the current management of hemolytic disease of the newborn.

Anomalous papillary muscle as a cause of left ventricular outflow tract obstruction in an adult.

Left ventricular outflow tract obstruction may be caused by abnormalities of the various structures comprised by the outflow tract. Hypertrophic cardiomyopathy is one of the more common causes, but many are rare anomalies, a collection of which we have compiled. We present a case of left ventricular outflow tract obstruction mimicking aortic stenosis in an adult. This was found to be due to abnormal insertion of a hypertrophied papillary muscle, successfully corrected by mitral valve replacement.

Differential free-radical activity after successful and unsuccessful thrombolytic reperfusion in acute myocardial infarction.

BACKGROUND: Free-radical generation after successful thrombolysis in acute myocardial infarction may jeopardize ischaemic but viable myocardium, thus limiting the optimal benefits of reperfusion. METHODS: Circulating free-radical activity was assessed in 25 consecutive patients with acute myocardial infarction. Those who successfully reperfused (Group A) were compared with those who did not (Group B). We also compared patients who had or had not developed Q waves and patients with and without previous angina or myocardial infarction. All patients presented within 6 h of the onset of chest pain and received standard intravenous streptokinase therapy. Free-radical activity in serial serum samples collected over 72 h was measured using the percentage molar ratio (PMR) of the concentrations of 9,11-linoleic acid to 9,12-linoleic acid, and malonaldehyde concentration. RESULTS: Throughout the study period Group A (n = 11) showed significantly greater change in serum PMR and malonaldehyde levels compared with Group B (n = 14) (P < 0.01). PMR differences between the two groups were most pronounced at 3 and 12 h (P < 0.001). Patients with non-Q-wave myocardial infarction (n = 5) showed significantly greater changes in serum PMR and malonaldehyde levels (P < 0.01) compared with those with Q-wave infarction (n = 20). A history of previous infarction or angina had no apparent effects on the changes in serum free-radical activity. CONCLUSIONS: Successful early reperfusion and non-Q-wave myocardial infarction are both associated with a significantly greater increase in the levels of markers of serum free-radical activity immediately after infarction. The results support present concepts of free-radical-mediated reperfusion injury. Use of these assays may identify those patients who may be at risk from free-radical-mediated reperfusion injury.

Early experience of directional coronary atherectomy: clinical results, complications and histopathological findings.

OBJECTIVE: To report the early experience, clinical results and histopathologic findings of Directional Coronary Atherectomy from a UK centre experienced in coronary angioplasty. DESIGN: Prospective study of the first 45 Directional Coronary Atherectomy (DCA) procedures using the Simpson coronary atherectomy device. RESULTS: Forty-five procedures were performed in 33 male and 5 female patients (mean age, 55.1 years). Directional Coronary Atherectomy was performed to 50 lesions (39 de novo, 11 restenosis; 44 left anterior descending, 3 right, 2 circumflex coronary arteries and 1 saphenous vein graft). Clinical and primary angiographic success was achieved in 43 of 45 cases (95.5%) and in 47 of 50 lesions (94%) after DCA alone. Before DCA the mean diameter stenosis was 88.7% (range, 50-100%) but following DCA (and percutaneous coronary angioplasty (PTCA) if necessary) the mean diameter stenosis was 3.5% (range, 0-15%; P < 0.001). Complications included occlusive dissection requiring coronary artery bypass surgery in two patients; abrupt closure of right coronary artery in one patient successfully reopened by PTCA and thrombolysis, complicated by excessive blood loss; reversible coronary artery spasm due to minor nose-cone trauma in four patients and temporary side branch loss in one patient. There were no coronary artery perforations, guide catheter complications, peripheral vascular trauma or deaths. On average 5.6 specimens (range, 1-18) were removed per case. Histology showed fibrous intimal plaque in 98%, media in 39% and adventitia in 7%. Neo-intimal hyperplasia was found in all restenosis lesions but also in 30% of de novo lesions. CONCLUSIONS: This small initial series indicates that directional coronary atherectomy is an effective and safe procedure for the treatment of obstructive coronary artery disease in carefully selected patients. With care, a high success rate can be achieved even during a learning phase. The technique is particularly effective for morphologically complex lesions that are unfavourable for PTCA. The procedure is unlike PTCA and requires additional training if pitfalls are to be avoided, high success rates achieved and complication rates kept low.

Clostridial endocarditis: report of a case caused by Clostridium septicum and review of the literature.

We describe a case of fatal infective endocarditis due to Clostridium septicum in a patient with underlying colonic carcinoma. This is believed to be the first reported case of C. septicum endocarditis. The literature on the subject is reviewed.

Rate of metabolism of norethisterone in women from different populations.

The rate of metabolism of orally administered norethisterone was compared in fourteen centres by measuring plasma levels of the steroid by radioimmunoassay at varying times after oral administration of a 1 mg dose. The inter-centre differences were of the same order as the intra-centre differences. Variations in metabolism appeared not to be due to variations in body size.

Pharmacokinetics of ethynyloestradiol in women for different populations.

The pharmacokinetics of a dose of 50 microgram ethynyloestradiol administered orally was studied in fourteen centres. Absorption was rapid and the highest serum concentrations of total ethynyloestradiol were found in most subjects at 1 h and by 24 h concentrations were less than 250 pg/ml. Calculation of the half-lives for absorption, distribution and elimination showed wide variations between subjects, the half-life of elimination varying from 2.5 h to more than 30 h. Bioavailability as measured by the area under the serum ethynyloestradiol concentration-time curve also showed more than a ten-fold variation. Intra-centre differences in the various parameters measured were as large as the inter-centre differences.

A prospective randomised study of continuous warm versus intermittent cold blood cardioplegia for coronary artery surgery: preliminary report.

Between October 1991 and March 1993, 281 consecutive patients underwent non-emergency isolated coronary artery surgery under the care of one surgeon (A.R.). They were prospectively randomised to receive either intermittent cold (Group I-144 patients) or continuous warm (Group II-137 patients) blood cardioplegia for myocardial protection. There were no significant differences in clinical outcome between the two groups, as judged by operative mortality, rates of peri-operative myocardial infarction, blood loss, need for circulatory support, post-operative neurological deficit, or duration of intensive care or hospital stay. However, sinus rhythm returned spontaneously with greater frequency (91.2% vs 45.8%, P < 0.001) in Group II patients. There was greater transmyocardial oxidative stress in Group I patients, as evidenced by a significant rise in oxidised glutathione in coronary sinus blood on myocardial reperfusion. Also, the serum CKMb isoenzyme level 2 h post-operatively was significantly raised in Group I patients, although this difference had disappeared by the day after surgery. In conclusion this preliminary report suggests that continuous warm blood cardioplegia provides comparable myocardial protection to that achieved with standard hypothermic techniques in patients undergoing coronary artery surgery.

Pharmacological measures to prevent post-operative urinary retention; a prospective randomized study.

One hundred patients undergoing vaginal surgery for genital prolapse were randomly allocated to one of four post-operative management groups which included a control group and three groups receiving differently acting pharmacological agents (distigmine bromide, phenoxybenzamine hydrochloride, and prostaglandin F2 alpha) variously reported as being useful in preventing urinary retention after vaginal surgery. The incidence of an elevated residual volume in the control group was 10.7%. All the pharmacological agents appeared to increase by about three times the incidence of an elevated residual urinary volume with statistical significance (P less than 0.05) being noted for distigmine bromide and PGF2 alpha. While this increased incidence occurred irrespective of the type of surgery in the case of distigmine bromide and phenoxybenzamine . HCl, the increase was most marked (P less than 0.01) when PGF2 alpha was used after anterior repair surgery.

Maternal mortality in the Maltese Islands.

Maternal mortality statistics from the Maltese Islands since 1935 are reviewed to show that there has been a marked decrease in maternal mortality rates. This decrease is probably related to reductions in family size and improvements in the perinatal care of mothers. Hypertensive disease is now the most important cause of maternal mortality.

PIP: This study attempts to analyze national maternal mortality and morbidity statistics collected for the Maltese Islands since 1935 in order to identify the current major causes of maternal deaths on the Islands. In 1926, the maternal mortality rate was an estimate 387.3/100,000 live births, white the rate in 1982 was 32.9/100,000 live births. This reflects a sharp decrease in the last 45 years. This decrease is probably related to reductions in family size and improvements in the preinatal care of mothers. Maltese women are having fewer pregnancies, are beginning childbearing when they are in their 20s or early 30s and are spacing their pregnancies at longer intervals. Improvements in the socioeconomic status of pregnant women in the Maltese Islands have also played an important role in decreasing maternal mortality and morbidity. hypertensive disease is now the most important cause of maternal mortality.

Multiple pregnancy in the Maltese population.

This study analyses the multiple birth statistics for the Maltese Islands since 1959. Hospital twin births delivering during the period of 1983-1985 are analysed for a number of variables. The incidence of multiple pregnancy for the Maltese Islands appears to have decreased slightly since 1959 with an overall rate of 10.21 per 1000 maternities. The ratio of dizygotic to monozygotic twinning was computed to be 1.64. Patients with multiple pregnancies are shown to be generally elderly and multiparous. The pregnancy outcome is more likely to be complicated by an operative delivery, while the infant is more likely to be premature and of low birth weight. The perinatal mortality rate for multiple pregnancies is markedly in excess of that for singleton births.

Risks in pregnant teenagers.

The teenage population delivering in Malta during 1983-1986 were identified and the maternal characteristics and obstetric outcome of these patients were statistically compared to those of mothers aged 20-29 years. Teenage mothers were more likely to be primigravida and poor attenders for antenatal care. They were more likely to be cigarette smokers and the pregnancies were more frequently complicated by threatened abortion. The perinatal mortality and morbidity was increased from problems of prematurity.

Perinatal mortality in the Maltese Islands.

This study analyzes the perinatal mortality statistics for the Maltese Islands since 1950 and compares them to those of other European countries. The mortality rate has taken a variable downward trend which can be correlated to important events during this period. Hospital perinatal mortality statistics are reviewed in the light of the national statistics.

PIP: This study analyzed national perinatal mortality statistics collected for the Maltese Islands in 1950-80. The perinatal mortality rate is defined as the number of stillbirths (after the 28th week of pregnancy) plus deaths occurring in the 1st week of life/1000 live births. During this period, the perinatal mortality rate showed a variable but definite downward trend that paralleled a decline in the crude birth rate. The sharp drop in the birth rate registered after 1962 may have contributed to the marked downward trend in the stillbirth rate after 1963 by decreasing the load on antenatal services. The early (1st week of life) neonatal death rate exhibited a sharp decline in 1953, which was the year several antenatal clinics aimed at serving women from the lower socioeconomic group in Malta were opened. These clinics helped to identify disorders of pregnancy that contribute to chronic placental insufficiency and fetal anoxia. Also contributing to the decline in perinatal mortality has been the increase in hospital versus home deliveries. In 1979, home deliveries accounted for only 1.8% of all deliveries in the Maltese Islands. The main government teaching hospital (St. Luke's) accounted for 54.9% and a smaller state-run hospital (Craig) delivered 4.6%; 2 private hospitals, St. Catherine's and Blue Sisters', delivered 21.8% and 16.9%, respectively. In 1980, maternity services at the 2 private hospitals were terminated, but a new maternal and child health complex equipped to provide better intrapartum and postpartum care was established at St. Luke's Hospital. An analysis of 339 perinatal deaths registered at St. Luke's Hospital in 1979-82 indicated that 54.6% were due to unavoidable factors, 33.6% involved avoidable factors attributable to the hospital or to factors outside the hospital, and 11.8% were unexplained. Facilities now exist to reduce perinatal mortality in the Maltese Islands even further; efforts must now be made to identify high-risk pregnancies earlier and more precisely.