The UK defence anaesthesia experience with the Zambia Anaesthesia Development Programme

For 18 months UK military anaesthetic trainees have been travelling to Zambia for a 3-month fellowship under the auspices of the Zambia Anaesthesia Development Programme. In this article we will discuss the history, current state and future intent of the fellowship in order to better inform the anaesthetic cadre and wider UK Defence Medical Services.

Structurally conserved binding motifs of transcriptional regulators to notch nuclear effector CSL

This mini review discusses the protein complexes comprised of the universal Notch signaling transcription factor, CSL (CBF1/Su(H)/Lag-1), and its activating or repressing transcriptional coregulation partners. Many of these complex structures have been solved crystallographically as well as undergoing extensive binding studies with wild-type and mutant variants. Notch signaling is critically important in a large variety of basic biological processes: cell proliferation, differentiation, cell cycle control to name a few. Aberrant Notch thus remains a coveted target for pharmaceutical intervention. To that end, we provide a molecular-level summary of the similarities and differences in the Notch coregulator complexes that ultimately govern these processes. We highlight a conserved binding motif that multiple superficially unrelated proteins have adopted to become involved in Notch target gene regulation. As CSL-interacting small molecules begin to be characterized, this review will provide insight to potential binding sites and differential complex disruption.

Impact statement

Proper Notch signaling regulation is informed by many distinct protein complexes involving a single nuclear effector. A decade of research into these protein complexes yields multiple crystal structures and a wealth of binding data to guide drug development for Notch-related diseases – cancer, cardiovascular, development disorders.

TRPM3 and miR-204 establish a regulatory circuit that controls oncogenic autophagy in clear cell renal cell carcinoma

Autophagy promotes tumor growth by generating nutrients from the degradation of intracellular structures. Here we establish, using shRNAs, a dominant-negative mutant, and a pharmacologic inhibitor, mefenamic acid (MFA), that the Transient Receptor Potential Melastatin 3 (TRPM3) channel promotes the growth of clear cell renal cell carcinoma (ccRCC) and stimulates MAP1LC3A (LC3A) and MAP1LC3B (LC3B) autophagy. Increased expression of TRPM3 in RCC leads to Ca(2+) influx, activation of CAMKK2, AMPK, and ULK1, and phagophore formation. In addition, TRPM3 Ca(2+) and Zn(2+) fluxes inhibit miR-214, which directly targets LC3A and LC3B. The von Hippel-Lindau tumor suppressor (VHL) represses TRPM3 directly through miR-204 and indirectly through another miR-204 target, Caveolin 1 (CAV1).

High altitude pulmonary oedema

High altitude pulmonary oedema (HAPE) is an important and preventable cause of death at high altitudes. However, little is known about the global incidence of HAPE, in part because most cases occur in remote environments where no records are kept. Furthermore, despite international efforts to achieve consensus, there is wide disparity in the diagnostic criteria in clinical and research use. We have reviewed the literature on the incidence and epidemiology of HAPE. There is broad agreement between studies that HAPE incidence at 2500m is around 0.01%, and increases to 1.9% at 3600m and 2.5-5% at 4300m. Risk factors for HAPE include rate of ascent, intensity of exercise and absolute altitude attained, although an individual pre-disposition to developing the condition is also well described and suggests an underlying genetic susceptibility. It is increasingly recognised that clinically-detectable HAPE is an extreme of a continuous spectrum of excess pulmonary fluid accumulation, which has been demonstrated in asymptomatic individuals. There is a continued need to ensure awareness of the diagnosis and treatment of HAPE among visitors to high altitude. It is likely that HAPE is preventable in all cases by progressive acclimatisation, and we advocate a pragmatic "golden rules" approach. Our understanding of the epidemiology and underlying genetic susceptibility to HAPE may be advanced if susceptible individuals register with the International HAPE Database: http://www.altitude.org/hape.php. HAPE has direct relevance to military training and operations and is likely to be the leading cause of death at high altitude.

Cuspal movement and microleakage in premolar teeth restored with posterior filling materials of varying reported volumetric shrinkage values

OBJECTIVES

To investigate the effect of polymerisation shrinkage stress of various aesthetic posterior filling materials on cuspal movement and cervical gingival microleakage of mesio-occlusal-distal (MOD) restorations placed in increments in extracted maxillary premolar teeth.

METHODS

Forty sound extracted upper premolar teeth were subjected to standardised preparation of a large MOD cavity. One curing regimen was used and each posterior filling material was placed in eight increments with the appropriate bonding system. A twin channel deflection-measuring gauge allowed a measurement of individual cusp deflections at each stage of polymerisation. Restored teeth were thermocycled before immersion in 0.2% basic fuchsin dye for 24h. After sagittal sectioning of the restored teeth in a mesio-distal plane, the sectioned restorations were examined to assess cervical gingival microleakage.

RESULTS

In general, cuspal deflection measurements were dependent upon the constituent monomers and the associated shrinkage on curing, with significantly increased cuspal movement (P<0.05) being recorded for Z100 (20.03+/-2.92 microm) compared with Filtek Z250 (12.34+/-2.18 microm), P60 (13.41+/-4.43 microm) and Admira (11.2+/-2.58 microm). No significant differences were identified between the posterior filling materials when the cervical gingival microleakage scores were examined.

CONCLUSIONS

It would appear that a reduction in the manufacturers' reported volumetric polymerisation shrinkage for Z100 (4.0%) to below 3% for Filtek Z250, P60 and Admira, resulted in a significant reduction in the associated cuspal strain on the MOD cavity. The diluent triethyleneglycol dimethacrylate (TEGDMA) increases the polymerisation shrinkage of Z100 resin-based composite due to an increased concentration of carbon-to-carbon double bonds (CC). The replacement of TEGDMA with urethane dimethacrylate (UDMA) and Bis-EMA in Filtek Z250 and P60, decreases the polymerisation shrinkage stress by increasing the cross-linking of polymer networks. However, no group was identified as producing less gingival microleakage at the cervical dentine cavosurface margin when the cavities were sectioned and examined, regardless of the reported variations in cuspal strain and the associated volumetric polymerisation shrinkage values.

Preventive mental health interventions in peacekeeping missions to Somalia and Haiti

Mental health interventions of the 528th Combat Stress Control unit to limit the numbers of psychiatric casualties on recent peacekeeping missions are discussed. Similarities and differences in the mental health support of Operation Restore Hope (Somalia) and Operation Uphold Democracy (Haiti) are reviewed. The mission to Somalia was marked by unexpected combat casualties. The mission to Haiti was marked by unexpected self-inflected casualties. Lessons learned by mental health officers serving on these missions are discussed. Recommendations for prevention of psychiatric casualties on future missions are presented.

Stress, suicide, and military service during Operation Uphold Democracy

The initial weeks of Operation Uphold Democracy were marked by a high rate of major axis I disorders among soldiers presenting for treatment at the 528th Combat Stress Center. The mission to Haiti was also marked by three suicides during the first 30 days. The author explores psychodynamic sources of stress that may have contributed to the high level of psychiatric acuity observed during that first month. Then, distinctions are made between psychiatric conditions that present in combat and those that occur on peacekeeping missions.

Stress and arousal in deployment of a combat support hospital

Two hundred thirty-nine soldiers from the 28th Combat Support Hospital were evaluated for stress and arousal during deployment preparations for Operation Uphold Democracy. We measured stress and arousal using the Stress Arousal Checklist and found increased levels of arousal in officers and older soldiers. We also found higher levels of arousal in soldiers reporting a greater number of hours of sleep during the preceding 24 hours. We found no significant difference in stress scores for several demographic and coping behavior groups. Based on lower arousal scores, younger, sleep-deprived, and enlisted soldiers may be at the highest risk for accidents during deployment preparations.

Helping the helper: 528th Combat Stress Center in Somalia

Seventy-three Rangers were injured and 18 were killed after an ambush in Somalia. Members of the 46th Combat Support Hospital provided nearly continuous care to the wounded soldiers over the subsequent 36 hours. Members of the 528th Combat Stress Center provided psychological support to hospital personnel. Those who provide emergency services to trauma victims are often neglected in terms of the emotional trauma they experience in caring for the injured. This article describes the use of critical incident stress debriefings as a means to reduce distress in the wake of mass-casualty care.

Frontal lobe cerebral aneurysm rupture presenting as psychosis

A 23 year old male with acute onset of blunted affect, looseness of associations and auditory hallucinations presented to a tertiary care hospital 10 days after development of symptoms. Before transfer, the patient received a diagnosis of schizophreniform disorder and treatment with haloperidol was started which resulted in moderate improvement. Examination led to detection of a ruptured cerebral aneurysm in the left frontal lobe. Evacuation of the haematoma and repair of the aneurysm resulted in nearly complete resolution of symptoms. The rare incidence of acute aneurysm rupture, presenting in the case described, demonstrates the importance of a complete neurological examination in the evaluation of acute mental status changes.

Identification and characterization of greater mood variance in depression

OBJECTIVE

The authors sought to assess the quantity and quality of mood variation in depressed persons.

METHOD

Using a visual analogue scale, they compared variation of mood in a group of patients (N = 9) with a DSM-III-R diagnosis of depressive disorder and in a group of nondepressed subjects (N = 9) over 12 consecutive hours. To quantify mood variation for each subject, the authors computed the standard deviation of each subject's 13 mood ratings on the visual analogue scale. To characterize the quality of mood variation within each subject, they plotted each subject's mood ratings as a function of time and applied complex demodulation to confirm cyclical patterns of mood variability (ultradian cycles).

RESULTS

The depressed group demonstrated greater mood score variability over the course of the day. Both groups demonstrated ultradian cycles and circadian trends; however, the depressed group demonstrated ultradian cycles of significantly greater amplitude than the nondepressed group.

CONCLUSIONS

Repeated assessments of mood at different times of the day may be necessary to obtain an accurate impression of a patient's mood state. Further, the mechanism of depressive disorders may include a deregulation of a normal oscillatory mood variation pattern.

High-affinity binding of [3H]acetylcholine to muscarinic cholinergic receptors

High-affinity binding of [3H]acetylcholine to muscarinic cholinergic sites in rat CNS and peripheral tissues was measured in the presence of cytisin, which occupies nicotinic cholinergic receptors. The muscarinic sites were characterized with regard to binding kinetics, pharmacology, anatomical distribution, and regulation by guanyl nucleotides. These binding sites have characteristics of high-affinity muscarinic cholinergic receptors with a Kd of approximately 30 nM. Most of the muscarinic agonist and antagonist drugs tested have high affinity for the [3H]acetylcholine binding site, but pirenzepine, an antagonist which is selective for M-1 receptors, has relatively low affinity. The ratio of high-affinity [3H]acetylcholine binding sites to total muscarinic binding sites labeled by [3H]quinuclidinyl benzilate varies from 9 to 90% in different tissues, with the highest ratios in the pons, medulla, and heart atrium. In the presence of guanyl nucleotides, [3H] acetylcholine binding is decreased, but the extent of decrease varies from 40 to 90% in different tissues, with the largest decreases being found in the pons, medulla, cerebellum, and heart atrium. The results indicate that [3H]acetylcholine binds to high-affinity M-1 and M-2 muscarinic receptors, and they suggest that most M-2 sites have high affinity for acetylcholine but that only a small fraction of M-1 sites have such high affinity.

Exposure to nicotine enhances the behavioral stimulant effect of nicotine and increases binding of [3H]acetylcholine to nicotinic receptors

Rats were given daily injections of nicotine sulfate in doses ranging from 0.1 to 0.4 mg/kg. The behavioral effect of these injections was measured as locomotor activity in photocell cages. Repeated administration of the same dose to each rat resulted in an enhancement of the stimulant effect of nicotine. This enhanced behavioral effect was quite pronounced within 5 days of repeated injection. Tissue from the cerebral cortex of these rats, exposed to nicotine for 5 days, was assayed for binding of [3H]acetylcholine to nicotinic receptors. These relatively small doses of nicotine resulted in 18-26% increases in cortical nicotinic receptors, compared to saline-treated rats. Rats exposed to 0.2 mg/kg of nicotine for 5 days and then given saline for 7 days still showed an enhanced behavioral response to nicotine on the eighth day after exposure, and nicotinic binding in the cortex was still elevated. However, 21 days after exposure to nicotine both the behavioral response to nicotine and the binding values had returned to the same values as those of saline-treated rats. These data imply that increased binding of [3H]acetylcholine to nicotinic sites and the enhanced behavioral effect of nicotine are functionally linked.

Percutaneous transluminal coronary angioplasty: an update on indications, techniques, and results

Despite continued efforts at disease prevention, coronary artery disease remains accountable for more than 500,000 deaths per year in the United States. Surgical intervention has assumed a well-deserved role over the past 16 years in disease palliation and receives wide application. More recently, PTCA has emerged as a proven technique for coronary revascularization that can be applied to a large group of patients with coronary artery disease. Clearly complementing bypass surgery, percutaneous dilatation offers certain advantages such as reduced emotional pain and suffering, sizable economic savings, and reduced time lost from work. As diagnostic technology continues to improve, the goal of early disease recognition and gentle nonsurgical resolution may well be accomplished in many individuals suffering from coronary artery disease.

Traumatic rupture of the thoracic aorta

Aortic transection secondary to blunt trauma is not an uncommon injury. Prompt recognition and treatment of the injury is required to salvage patients with this type of injury. Ten patients with transection of the thoracic aorta at the isthmus have been treated in the past two years at our institution. There have been two operative deaths, one delayed hospital death, and seven survivors. We believe the use of a temporary shunt of heparin-bonded polyvinylchloride during the repair of the aorta offers significant advantages over other methods which have been described.

Coarctation of the aorta

A review of the congenital anomaly of coarctation of the aorta has been presented. The salient features in diagnosis are the differential pressures and pulses between the upper and lower extremities. Also, the features of left ventricular hypertrophy and pulsating intercostal vessels are significant. The essential complications are those of sustained hypertension. In most cases surgical correction can be accomplished with excision of the coarcted segment and an end-to-end anastomosis. In some instances, particularly in adults, a graft may be necessary. The surgical results have been gratifying with a mortality rate of less than 5 per cent and in general a reduction of the blood pressure to normal.