Search for magnetic monopoles in polar volcanic rocks.

For a broad range of values of magnetic monopole mass and charge, the abundance of monopoles trapped inside Earth would be expected to be enhanced in the mantle beneath the geomagnetic poles. A search for magnetic monopoles was conducted using the signature of an induced persistent current following the passage of igneous rock samples through a SQUID-based magnetometer. A total of 24.6 kg of rocks from various selected sites, among which 23.4 kg are mantle-derived rocks from the Arctic and Antarctic areas, was analyzed. No monopoles were found, and a 90% confidence level upper limit of 9.8 × 10(-5)/g is set on the monopole density in the search samples.

Magnetised quark nuggets in the atmosphere.

A search for magnetised quark nuggets (MQN) is reported using acoustic signals from hydrophones placed in the Great Salt Lake (GSL) in the USA. No events satisfying the expected signature were seen. This observation allows limits to be set on the flux of MQNs penetrating the Earth's atmosphere and depositing energy in the GSL. The expected signature of the events was ​derived from pressure pulses caused by high-explosive cords between the lake surface and bottom at various locations in the GSL. The limits obtained from this search are compared with those obtained from previous searches and are compared to models for the formation of MQNs.

Mass distribution of magnetized quark-nugget dark matter and comparison with requirements and observations.

Quark nuggets are a candidate for dark matter consistent with the Standard Model. Previous models of quark nuggets have investigated properties arising from their being composed of strange, up, and down quarks and have not included any effects caused by their self-magnetic field. However, Tatsumi found that the core of a magnetar star may be a quark nugget in a ferromagnetic state with core magnetic field Bsurface = 1012±1 T. We apply Tatsumi's result to quark-nugget dark-matter and report results on aggregation of magnetized quark nuggets (MQNs) after formation from the quark-gluon plasma until expansion of the universe freezes out the mass distribution to ~ 10-24 kg to ~ 1014 kg. Aggregation overcomes weak-interaction decay. Computed mass distributions show MQNs are consistent with requirements for dark matter and indicate that geologic detectors (craters in peat bogs) and space-based detectors (satellites measuring radio-frequency emissions after passage through normal matter) should be able to detect MQN dark matter. Null and positive observations narrow the range of a key parameter Bo ~ Bsurface to 1 × 1011 T < Bo ≤ 3 × 1012 T.

Stable five- and six-coordinated silicate anions in aqueous solution.

Addition of aliphatic polyols to aqueous silicate solutions is shown to yield high concentrations of stable polyolate complexes containing five- or six-coordinated silicon. Coordinating polyols require at least four hydroxy groups, two of which must be in threo configuration, and coordinate to silicon via hydroxy oxygens at chain positions on either side of the threo pair. The remarkable ease by which these simple sugar-like molecules react to form hypervalent silicon complexes in aqueous solution supports a long-standing supposition that such species play a significant role in the biological uptake and transport of silicon and in mineral diagenesis.

Effect of a pathway bundle on length of stay.

BACKGROUND: Pathways to guide clinical care are well accepted and used in many emergency departments. We wanted to introduce a number ("bundle") over a short space of time and involve the whole patient stay in the pathway. It was hypothesised that a more efficient process would result with an overall reduction in length of stay (LoS). METHODS: A "bundle" of 14 evidence-based pathways of care was introduced into a medium-sized district general hospital (DGH) in late 2006/early 2007. These pathways covered emergency department care and acute medical care for a period of up to 48 h. A total of 8184 acute emergency admission episodes were audited, 3852 in the 8 months before introduction of the new pathways and 4332 in the 8 months after their introduction. RESULTS: The overall effect of introducing the pathway bundle had a trend towards reduction in LoS by 0.2 days (95% CI -0.2 to 0.5), but this was not statistically significant (p>0.1). However, in those patients with

Detection of magnetized quark-nuggets, a candidate for dark matter.

Quark nuggets are theoretical objects composed of approximately equal numbers of up, down, and strange quarks and are also called strangelets and nuclearites. They have been proposed as a candidate for dark matter, which constitutes ~85% of the universe's mass and which has been a mystery for decades. Previous efforts to detect quark nuggets assumed that the nuclear-density core interacts directly with the surrounding matter so the stopping power is minimal. Tatsumi found that quark nuggets could well exist as a ferromagnetic liquid with a ~1012-T magnetic field. We find that the magnetic field produces a magnetopause with surrounding plasma, as the earth's magnetic field produces a magnetopause with the solar wind, and substantially increases their energy deposition rate in matter. We use the magnetopause model to compute the energy deposition as a function of quark-nugget mass and to analyze testing the quark-nugget hypothesis for dark matter by observations in air, water, and land. We conclude the water option is most promising.

Influence of DH/DL alleles regulating debrisoquine oxidation on phenytoin hydroxylation.

Eleven subjects of previously determined debrisoquine oxidation phenotype status (extensive metabolizer [EM], n = 5; poor metabolizer [PM], n = 6) were studied for their ability to perform the aromatic 4-hydroxylation of phenytoin. The PM subjects studied were found to be slower metabolizers of phenytoin than EM subjects in terms of the metabolite formation rate constant (kfHPPH: EM, 0.030 +/- .007 hr-1; PM, 0.016 +/- 0.003 hr-1, 2p less than 0.001) and cumulative excretion of 4-hydroxyphenytoin (48 hr after dosing: EM, 52.8 +/- 10.7%; PM, 36.9 +/- 7.0%, 2p less than 0.01). It is concluded that the metabolic oxidation of phenytoin is influenced by the same DH and DL alleles, acting at the same locus, that regulate the hydroxylation of debrisoquine and that impaired metabolism of phenytoin may be expected to occur in about 9% of the population, being transmitted as an autosomal-recessive trait. It is suggested that debrisoquine oxidation phenotyping may have predictive value in guiding phenytoin dosage, particularly in those with impaired oxidation.

Debrisoquin hydroxylation polymorphism among Ghanaians and Caucasians.

The alicyclic and aromatic hydroxylation of debrisoquin was studied in Ghanaians. As in a previously studied Caucasian population, the alicyclic 4-hydroxylation of debrisoquin in Ghanaians was polymorphic. Three phenotypes were observed: homozygous extensive metabolizers (58%), heterozygous extensive metabolizers (36%), and homozygous poor metabolizers (6%). In contrast, British Caucasians are primarily monomorphic extensive metabolizers (92%) and homozygous poor metabolizers comprise 8% of the population. Urinary recovery of the drug and its hydroxylated metabolites was significantly less in the Ghanaian subjects. In both Ghanaian and British populations, aromatic hydroxylation producing 5-, 6-, 7-, and 8-hydroxydebrisoquin was shown to parallel the alicyclic 4-hydroxylation of debrisoquin, and thus to be controlled by the same gene locus. Debrisoquin is advocated as a tool for uncovering polymorphism in drug oxidation and its interethnic variations.

Measurement of aortic root size by biplane angiography before cardiac valve replacement.

Aortic valve replacement (AVR) in the patient with a small aortic root demands special consideration because the hemodynamic function of artificial valves with a small external diameter is often poor. In this study, the internal diameter of the aortic root was measured from biplane ventriculography. This measured root diameter was then used to predict the external diameter of the artificial valve. Twelve patients underwent biplane ventriculography followed by AVR with Carpentier-Edwards bioprostheses. The artificial valve diameter was predicted with a correlation coefficient of 0.93, a standard error of estimate of 0.89 mm, and an average absolute difference between preoperative measurement and valve diameter of 0.69 mm. Therefore, the aortic root diameter can be accurately measured from the ventriculogram, thus detecting the patient with a small aortic root before surgery.

Genetic heterogeneity of histamine H2-receptors in the mouse vas deferens.

The ability of histamine to inhibit the overall contractile ('twitch') response of the isolated vas deferens of the mouse to electrical field stimulation (64 V pulse, 1 ms pulse width, frequency 0.2 Hz) was studied in nine inbred mouse strains. The strains were also characterized in terms of the potency of the histamine H2-receptor antagonist cimetidine in its inhibition of histamine-mediated effects. An apparently bimodal inter-strain variation (8-10 fold) in both characteristics was encountered, with three strains (SWR, A2G and C57BL/10ScSn) relatively sensitive (S) to both agonist and antagonist actions, and six (C3H, A, C57/BL6, DBA/2, Balb/C and 129/Sv) relatively insensitive (IS). These strain differences were independent of extracellular calcium concentration in the range 1.25-5 mM, and also independent of the frequency of tissue stimulation over the range 0.2-6.4 Hz. Representative S (SWR and A2G) and IS (DBA/2 and C3H) mouse vasa were also characterized in terms of their sensitivity to the agonist actions of dimaprit and the antagonist actions of tiotidine. In the S strain tissues, dimaprit produced 50% inhibition of the twitch response at 4.6-1.8 microM (mean +/- s.d.) and was able to elicit complete inhibition of the twitch response at concentrations greater than 100 microM, whereas 48.7 +/- 11.9 microM dimaprit was required to produce 50% inhibition of the twitch response in tissues from IS mice. In addition, the agonist actions of dimaprit were incomplete in the latter tissues, the drug eliciting no more than 75% inhibition of the twitch response at concentrations in the range 300-1000 microM. Tiotidine produced competitive antagonism of the actions of both histamine and dimaprit, the strain differences being of the same magnitude as those observed for cimetidine. 4 Mating of a representative S (SWR) and IS (129/Sv) strain produced F, mice with intermediate histamine and cimetidine sensitivities relative to the parental strains. A backcross of male F1 to female IS mice produced progeny displaying a range of histamine and cimetidine sensitivities representative of those seen in tissues from F1 and IS parental animals, however, the data were not bimodal. Thus, the backcross data provided no evidence to support single gene inheritance of histamine sensitivity and might suggest that more than one gene is responsible for these differences between S and IS mice.

Some observations on the oxidation phenotype status of Nigerian patients presenting with cancer.

The hypothesis is being explored that there may be an association between genetically determined oxidation status and propensity to develop carcinoma in response to environmental chemical carcinogens. For this purpose, the genetic structure of a normal, healthy Nigerian population with respect to oxidation status, has been compared with that found for a group of 59 Nigerian patients presenting with carcinoma of the liver and gastrointestinal tract. Genetically determined oxidation status was assessed by measuring the extent of oxidation of a probe drug, debrisoquine, to its major metabolite, 4-hydroxydebrisoquine. The cancer group contained a disproportionately large number of individuals who were extensive oxidizers compared to the controls (2 P = 0.0045). The findings support the view that genetically determined oxidation status may be an important host factor in influencing responsiveness to chemical carcinogens that require oxidative metabolic activation.

Role of the nurse in the multidisciplinary team approach to care of liver transplant patients.

Nursing plays an important contributory role in the multidisciplinary team approach to patient care. The nurse who is responsible for the care of liver transplant patients requires special preparation to meet the patient's needs during the critical phases of the liver transplant process. In the hospital setting, a primary nursing-care delivery system enhances the nurse's role in supporting the goal of patient recovery. Primary nursing places the accountability and responsibility for planning, administering, and evaluating the care of the liver transplant patient with the primary nurse. The transplant nurse acts as a key link in the communication network within the multidisciplinary team, and effective communication is essential in the care of the liver transplant patient. For achievement of a life-style of independence after transplantation, the patient is assisted by the nurse, who provides instruction in such areas as diet, medications, monitoring of vital signs, and record keeping. Although the nurse is only one member contributing to the care of liver transplant patients, the nurse's role in the success of treatment is vital.

Large mediastinal hematomas not associated with aortic rupture. Case presentations and surgical approach.

Mediastinal hematomas not associated with aortic disruption are thought to be common entities, and it is generally believed that most will spontaneously resolve. However, large mediastinal hematomas can cause fluctuations in cardiorespiratory physiology and can even cause death. Three cases of mediastinal hematomas are presented, as well as their surgical approach. Mediastinal hematomas should be evacuated because of their potential morbidity and mortality.

Anesthetic effects on electrophysiologic recordings.

With the increased use of intraoperative monitoring of the central nervous system (CNS) has come a need for better understanding of the effects of anesthetic agents on intraoperative recordings. The commonly used anesthetic agents and their effects on intraoperative electroencephalography (EEG) and evoked potentials (EP) are discussed. Halogenated inhalational anesthetics produce dose-related reduction in EEG amplitude and frequency after an initial activation. They also produce dose-related decreases in amplitude and increases in latency of sensory evoked potentials (SEP) that are most marked in cortically generated components. Subcortical, spinal, and peripheral evoked responses are less affected. Responses in the motor pathways are recordable in the epidural space; however, the relative contributions of sensory and motor tracts may be changed when both are present. Muscle responses are easily suppressed after spinal and motor cortex stimulation, probably by anesthetic effect at the anterior horn cells of the spinal cord. Intravenous analgesic agents (opioids, ketamine) are associated with less marked changes in EEG and evoked responses, with some increases in amplitude of cortically generated SEP caused by ketamine. Intravenous sedative-hypnotic drugs (droperidol, barbiturates, benzodiazepines, etomidate, propofol) produce dose-related depression of the EEG after initial activation and dose-related depression of evoked responses to a lesser extent than do the inhalation agents. Etomidate is associated with amplitude enhancement of EEG and cortically generated SEP. Muscle relaxants have minimal effect on the EEG and SEP. Their use, however, may alter muscle recordings from motor tract stimulation. These effects and their relevance to the choice of agents for specific monitoring techniques are discussed.

The pharmacokinetics of tritiated ethinylestradiol in the rabbit.

The disappearance of ethinylestradiol from the blood of rabbits has been studied, following the intravenous administration of this steroid. The disappearance followed two exponentials, the first having a half life (t1/2) of 5.5 min and the second, apparently terminal exponential was also rapid (t1/2-69 min). The plasma clearance was 150 ml/min which suggests almost total clearance of this steroid during a single passage through the liver. Bile contained a significant concentration of EE conjugates and thus this steroid could undergo enterophepatic recirculations. A large oral dose of unlabelled EE, given prior to intravenous administration of tritiated EE, considerably altered the pharmacokinetics of the latter by saturating both phase one metabolism (changes of the steroid nucleus) and the secretion of conjugates into bile. It was not clear whether phase two metabolism (conjugation) was also saturated.

Neurologic monitoring.

This article discusses the current methods for monitoring the intracranial environment in the critical care setting. Intracranial pressure monitoring is discussed first. Then the electroencephalogram and sensory evoked potentials are considered. Finally, new techniques being evaluated are discussed.

Detection of sacral sparing in acute spinal cord injury.

Sacral dermatomal-evoked responses (DEP) and posterior tibial nerve (PTN) somatosensory-evoked potentials (SSEP) were recorded 28 hours after gunshot injury to the 12th thoracic vertebra of a 17-year-old male. Repeatable responses were obtained from stimulation of the fourth sacral dermatome despite absence of repeatable PTN responses. This suggestion of "sacral sparing" was accompanied by clinical improvement of neural function during the hospital course and 10 months after discharge. This case suggests DEP can make valuable contributions in the diagnosis of sacral sparing in acute spinal cord injury. Considerations regarding the unusual ipsilateral scalp recording location for sacral DEP are discussed.

An approach to airway management in the acutely head-injured patient.

The rapid and safe establishment and maintenance of an adequate airway in patients with acute, severe head injuries is of central importance in the "ABC" approach to the trauma victim. It is also necessary before hyperventilation can be instituted as a means of controlling intracranial pressure. A method of establishing an airway in a manner that best protects the patient from unnecessary elevations in intracranial pressure with the least possible risk is presented. This method can be applied in virtually all emergency departments, from community hospitals to teaching centers, using materials and expertise currently available.

Minimally invasive reoperation through a lateral thoracotomy for circumflex coronary artery bypass.

We report 4 cases of redo coronary artery bypass grafting in which the circumflex coronary artery was successfully revascularized using a minimally invasive approach. In reoperative cases, it is easier to approach the circumflex coronary artery from the left side than from the front. Minimally invasive direct coronary artery bypass technology has made it possible to avoid using cardiopulmonary bypass. In our 4 cases, the revascularization procedure was performed via a small left thoracotomy, and without cardiopulmonary bypass. The patients made a good recovery and are free of angina 22 months after operation. We conclude that the thoracotomy approach provides the opportunity to avoid several hazards: a redo sternotomy, dissection of a hostile mediastinum, and manipulation of the heart.

Multiple endocrine neoplasia syndrome, type III: review and case report.

Successful treatment of the multiple endocrine neoplasia type III (MEN III) syndrome requires early diagnosis. It is highly possible that the patient's dentist may be the first practitioner with the opportunity to diagnose this potentially fatal syndrome. Additionally, patients with this syndrome having a pheochromocytoma and needing invasive dental treatment pose a life-threatening dental management risk. This article presents a review of the MEN II syndrome and a case report on the surgical management of a MEN III patient with a pheochromocytoma.