The sandhopper Talitrus saltator (Crustacea: Amphipoda) as a biomonitor of trace metal bioavailabilities in European coastal waters.

The amphipod crustacean Talitrus saltator is an established, easily accessible, biomonitor of trace metal bioavailabilities in coastal waters. We have carried out a geographically widespread collection of T. saltator from European shores, stretching from the north-west Atlantic through the Baltic to the Mediterranean. A primary aim of the work was to establish a database of accumulated trace metal concentrations (Cd, Cr, Cu, Fe, Mn and Zn) in this biomonitor. Statistical analysis has shown significant geographical differences in the bioavailabilities of all the metals, the most distinct being copper, iron and manganese. It has proved possible to identify unusually high accumulated concentrations of Cd, Cr, Cu, Fe, Mn and Zn in this biomonitor, indicative of high metal bioavailability at a particular site. These may serve as reference points for future biomonitoring programmes seeking to identify metal contamination in coastal waters.

Legal aspects of conserving native oysters in Scotland.

Native oysters (Ostrea edulis) historically supported valuable fisheries in Scotland, but are now absent from areas of former abundance on the east coast and occur mainly in isolated populations in west coast sea lochs. The main contemporary threat is from unauthorized gathering. In most places, the exclusive right to gather is retained by the Crown, as a remnant of the feudal system, but in some areas the right has been acquired by individuals or institutions. A temporary right to gather oysters may be obtained by permit from the proprietor, or through a Several or Regulating Order made under shellfish fisheries legislation. The right to gather oysters is separate from ownership of the foreshore or sea bed on which they are located. To receive the maximum legal protection, oyster beds must be marked out, or the rights to them otherwise adequately made known. Wild or formerly-cultivated oyster beds may not meet this criterion and, in any case, enforcement is difficult in remote locations. It has been proposed that there should be a statutory public right to gather oysters. Were this to be created, then strong conservation measures would need to be implemented to protect native oysters from eradication by uncontrolled gathering.

Effects of hypertonic saline on regional function and blood flow in canine hearts during acute coronary occlusion.

Small-volume resuscitation using hypertonic saline (7.5%) is effective for various types of shock. Recently, hypertonic saline has been proposed for fluid management in patients with impaired cardiovascular function. Whether hypertonic saline is safe in the compromised heart during coronary occlusion is not known. We examined the effects of hypertonic saline at 4 mL.kg-1 on myocardial function and blood flow during acute coronary occlusion. In anesthetized dogs, the left ventricle (LV) was instrumented with pressure and ultrasonic dimension transducers. Myocardial contractility was assessed using percent of systolic shortenings measured in both normal or ischemic regions. Blood flow distribution was measured using radioactive microspheres. Percent of systolic shortening and blood flow in the normal myocardium, unaltered by coronary occlusion, increased significantly after hypertonic saline from 11.0 +/- 1.1% to 13.7 +/- 1.4% and from 120 +/- 13 mL.min-1.100 g-1 to 169 +/- 13 mL.min-1.100 g-1, respectively. In the ischemic myocardium, occlusion of the left anterior descending coronary artery markedly decreased percent of systolic shortening from 13.0 +/- 1.2% to 9.3 +/- .9% and blood flow from 98 +/- 13 mL.min-1.100 g-1 to 19 +/- 10 mL.min-1.100 g-1. At peak effect of hypertonic saline contractility and blood flow in the ischemic myocardium decreased to 7.4 +/- .8% and 12 +/- 5 mL.min-1.100 g-1, respectively. Five of the nine dogs developed premature ventricular beats during hypertonic saline infusion. However, no significant changes were observed when normal saline was given at equivalent volumes to hypertonic saline in six dogs. Hypertonic saline was associated with significant increases in heart rate (from 116 +/- 3 beats.min-1 to 129 +/- 5 beats.min-1) and cardiac output (from 2.54 +/- .17 L.min-1 to 3.32 +/- .26 L.min-1). Except for an improved perfusion in the skin, hepatic arterial, and coronary beds, blood flow to the muscle, spleen, jejunum, kidney, and brain was not significantly altered by hypertonic saline. Our data demonstrates variant effects of hypertonic saline on either normal or ischemic myocardium. Whereas contractile function and blood flow in the normal myocardium were improved after hypertonic saline infusion, further decreases in blood flow and contractile function in region distal to coronary occlusion could lead to worsening of ischemic injury. These data suggest that hypertonic saline may be deleterious in hearts with impaired contractile function caused by ischemia.

Airway thermal volume in humans and its relation to body size.

The objective of this study was to investigate the influence of volume ventilation (VE) and cardiac output (Q) on the temperature of the expired gas at the distal end of the endotracheal tube in anesthetized humans. In 63 mechanically ventilated adults, we used a step decrease in the humidity of inspired gas to cool the lungs. After change from humid to dry gas ventilation, the temperature of the expired gas decreased. We evaluated the relationship between the inverse monoexponential time constant of the temperature fall (1/tau) and either VE or Q. When VE was increased from 5.67 +/- 1.28 to 7.14 +/- 1.60 (SD) l/min (P = 0. 02), 1/tau did not change significantly [from 1.25 +/- 0.38 to 1.21 +/- 0.51 min-1, P = 0.81]. In the 11 patients in whom Q changed during the study period (from 5.07 +/- 1.81 to 7.38 +/- 2.45 l/min, P = 0.02), 1/tau increased correspondingly from 0.89 +/- 0.22 to 1. 52 +/- 0.44 min-1 (P = 0.003). We calculated the airway thermal volume (ATV) as the ratio of the measured values Q to 1/tau and related it to the body height (BH): ATV (liters) = 0.086 BH (cm) - 9. 55 (r = 0.90).

Copper and zinc in an ecological series of talitroidean Amphipoda (Crustacea).

Cu and Zn concentrations were determined for the following talitroidean amphipods, Hyale nilssoni (Rathke), Talitrus saltator (Montagu), Talorchestia deshayesii (Audouin), Orchestia mediterranea Costa, O. gammarellus (Pallas), O cavimana Heller and Arcitalitrus dorrieni (Hunt) in September 1986 from sites in W. Britain (mostly Scottish). To minimize size effects, only animals >2mg body dry weight were included in analyses. Only Talorchestia (Cu & Zn) and O. cavimana (Zn) showed any residual relationship between metal concentration and dry weight. Log transformed data for concentrations of each metal against log dry wt. in all species were compared by ANCOVA. Copper and zinc concentrations of males and females were not significantly different in O. gammarellus, O. mediterranea and T. deshayesii, though Cu (but not Zn) concentrations differed with sex in O. cavimana. The order of species when ranked according to an ascending series of Cu concentrations (at standard body weight) reflected their ecological zonation from sea to land closely, with species living proximal to the sea having lowest Cu concentrations. The 6 talitrid species all had similar Zn concentrations but the Zn concentration of H. nilssoni was considerably lower. There was a relationship between Cu and Zn concentrations in individuals of only one species (O. gammarellus). Data on Cu and Zn concentrations for O. gammarellus derived from the same site in September 1983 were almost exctly the same as in September 1986. The possible impact of seasonal variation on haemocyanin levels is discussed.

Respiratory failure after chest injury: the development of effective treatment.

The development of methods of treatment of severe chest injury over the years is reviewed and the contribution made by the introduction of intensive care units is assessed. A comparative analysis of the results of treatment in large series of patients reported during the period 1946-78 shows that, despite the risk of complications, the addition of artificial ventilation to conservative methods of treatment reduces mortality in patients with respiratory failure associated with chest trauma.

Incremental evaluation of risky choices.

This paper compares the incremental method of valuation and its possible effects on choices analysed through utility theory with similar zero-base valuations. Analysis shows how biases can arise using incremental valuations in situations with decreasing risk aversion. This could be important in certain circumstances, e.g. delegated decision-making in cases where the total value of an organisation is unknown to the decision-maker or difficult to quantify.

The background to the proposition that plankton be used as food in the United Kingdom during the Second World War.

Food shortages, particularly of proteins, in Britain during the Second World War led to the suggestion re-surfacing that marine plankton might be harvested on an industrial scale first as human food, then turning to its potential use as a supplement to stock and poultry feed. The notion emanated in the United Kingdom from Sir John Graham Kerr, at Glasgow University. He encouraged Alister Hardy, at Hull, to develop the idea and the natural testing ground was the Clyde Sea Area (given the extensive history of plankton research at Millport). Unpublished documents from the archives of the Scottish Association for Marine Science shed new light on the interactions behind the scenes of this project between Kerr, Hardy and the Millport Marine Station's then director, Richard Elmhirst. Elmhirst, who was sceptical about the feasibility of the plan from the outset, went along with it; not least as a way of attracting welcome research funding during lean times but also, doubtless, regarding it as his patriotic duty in case the proposal proved worthwhile.

Illustrations and the genesis of Barrett and Yonge's "Collins pocket guide to the sea shore" (1958).

Twenty nine items of correspondence from the mid-1950s discovered recently in the archives of the University Marine Biological Station Millport, and others made available by one of the illustrators and a referee, shed unique light on the publishing history of "Collins pocket guide to the sea shore". This handbook, generally regarded as a classic of its genre, marked a huge step forwards in 1958; providing generations of students with an authoritative, concise, affordable, well illustrated text with which to identify common organisms found between the tidemarks from around the coasts of the British Isles. The crucial role played by a select band of illustrators in making this publication the success it eventually became, is highlighted herein. The difficulties of accomplishing this production within commercial strictures, and generally as a sideline to the main employment of the participants, are revealed. Such stresses were not helped by changing demands on the illustrators made by the authors and by the publishers.

Preparation of the intensive care patient for major surgery.

Improved methods for monitoring and treating critically ill patients have increased the number of surgical candidates with multiorgan system impairment. Whereas such patients may have been considered "too sick to undergo surgery" in the past, many such patients linger in the intensive care unit unless definitive therapy is accomplished. Specific attention to review of the patient's preoperative preparation for surgery on a system-by-system basis may improve outcome substantially. The need for possible mechanical ventilation prior to transport to the operating room must receive particular attention. Pneumothorax, if present, must be treated prior to institution of positive-pressure ventilation so progression to tension pneumothorax can be avoided. Deficits in the circulating blood volume must be identified and corrected preoperatively if possible. A need for enhancement of cardiac output or alteration of vascular tone requires pulmonary arterial catheterization and indicates an increased operative risk. Metabolic abnormalities such as disturbances of acid-base balance, sodium or potassium concentration, and endocrinopathies are identified and corrected as much as possible prior to operation. Antibiotics are instituted as appropriate. Replacement of the red blood cell mass is dictated primarily by anticipated or actual blood loss. Factors of coagulation are infused on a replacement basis as necessary. Great care must be taken during transport to the operating room, as maintenance of intravascular monitoring devices, therapeutic infusions, and mechanical ventilation must continue during transport. Precautions must be taken to avoid hypothermia during transport and institution of anesthesia. Critical illness mandates specific considerations of the anesthetic agents to be utilized.

Causes of death after blunt chest injury.

During the 10 years from 1968 a total of 1119 patients with chest and associated injuries were admitted to the Royal Newcastle Hospital (RNH); 530 of these needed ICU treatment and fifty-nine died. Common causes of death included irreparable associated injuries to brain and exsanguination due to major vessel injury. However, the commonest cause encountered was refractory respiratory failure due to pulmonary sepsis. This condition was associated with hypovolaemic shock, intra-abdominal injuries, failure of conservative treatment and injuries in the older age groups.

Tracheostomy in the management of chest injuries: its use and complications.

During the period March 1968 to June 1978 a total of 238 adult patients received long term artificial ventilation for acute respiratory failure following chest and associated injuries. In 180 of these tracheostomy was used as the means of access to the tracheobronchial tree. Our indications for tracheostomy in these patients, details of treatment and the complications which resulted from this aid to management are given. The lack of serious complications suggests that tracheostomy can be used safely and with advantage in the management of acute respiratory failure after injury.

Inhibition of nitric oxide synthesis causes systemic and pulmonary vasoconstriction in isoflurane-anesthetized dogs.

The postulate that the hemodynamic changes produced by isoflurane (1.5%) involve release of nitric oxide (NO) was examined. Fifteen dogs were anesthetized with thiamylal (15 mg/kg) and ventilated with isoflurane and oxygen. Catheters were inserted for measurement of aortic pressure, pulmonary artery pressures, and determination of cardiac output. Left thoracotomy was performed and complete heart block was induced by injection of 37% formaldehyde (0.3 mL) into the atrioventricular node; ventricular rate was fixed at 100 beats/min by external pacing. An apical microtransducer was inserted into the left ventricle (LV) via the apex for measurement of left ventricular pressure (LVP) and its first derivative (dP/dt). Flow probes were mounted on the left circumflex (Cx) and anterior descending (AD) coronary arteries. Measurements were obtained before (control period) and during NO inhibition using IV NG-nitro-L-arginine methyl ester (L-NAME) by a 50 mg/kg bolus plus 1 mg/kg/min. Infusion of L-NAME caused immediate and sustained increases in mean arterial pressure to 145 +/- 3% (P < 0.001), mean pulmonary arterial pressure to 128 +/- 5% (P < 0.001), pulmonary capillary wedge pressure to 144 +/- 8% (P < 0.001), coronary perfusion pressure to 163 +/- 4% (P < 0.001), systemic vascular resistance to 209 +/- 9% (P < 0.001), pulmonary vascular resistance to 142 +/- 12% (P < 0.005), anterior descending flow to 115 +/- 4% (P < 0.005), and circumflex flow to 113 +/- 3% (P < 0.01) of control levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular function during induced hypotension by fenoldopam or sodium nitroprusside in anesthetized dogs.

Fenoldopam, a selective dopamine1 receptor agonist, has been recommended for induced hypotension because it effectively lowers arterial blood pressure and improves renal perfusion. We examined cardiovascular functions during hypotension induced by fenoldopam or sodium nitroprusside. In eight halothane-anesthetized dogs, the left ventricle (LV) was instrumented with pressure and ultrasonic dimension transducers for the assessment of LV contractility using the analysis of the pressure-diameter relationship. Blood flow distribution was measured by radioactive microspheres. Doses of fenoldopam and nitroprusside were titrated to reduce mean arterial blood pressure to 60 mm Hg. After 40 min of hypotension, fenoldopam and nitroprusside caused similar increases in heart rate (17% +/- 4% vs 19% +/- 10%, respectively) and decreases in systemic vascular resistance (-24% +/- 5% vs -27% +/- 4%). Hypotension induced by fenoldopam was associated with higher LV end-diastolic pressure (4.4 +/- 0.6 vs 2.5 +/- 1.1 mm Hg) and end-systolic meridional wall stress (33.0 +/- 4.3 vs 17.8 +/- 2.1 g/cm2) when compared with nitroprusside. There were no significant changes in cardiac output and cardiac contractility as expressed by the slope (Ees) of the LV end-systolic pressure-diameter relationship, velocity of shortening of the diameter, and percentage of wall thickening of the LV. In contrast to nitroprusside, which decreased renal blood flow from 197 +/- 19 to 163 +/- 15 mL/min, renal blood flow increased during fenoldopam-induced hypotension from 187 +/- 20 to 239 +/- 18 mL/min. The increase in renal perfusion was similar in upper, middle, and lower regions of the kidney; however, it was more in the medulla compared with the cortex (37% +/- 17% vs 25% +/- 7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Tracheobronchial and oesophageal ruptures caused by blunt injury.

During the period 1968-1982, six patients with tracheobronchial ruptures following chest injury were treated in the Royal Newcastle Hospital Intensive Care Unit. In one there was associated oesophageal rupture. The management of these patients is described and recommendations regarding management are made.

Haemodynamic compromise during thoracoscopic/laparoscopic oesophagectomy.

Minimally invasive oesophagectomy is a relatively new procedure that is performed by means of thoracoscopy and laparoscopy. One stage of the procedure involves creation of a peritoneo-pleural communication in the presence of a pneumoperitoneum. In the case presented, severe hypotension occurred at this point. We believe this was caused by the escape of carbon dioxide from the peritoneal cavity into the right hemithorax, resulting in tension pneumothorax and cardiac tamponade. We believe this to be a predictable complication of this procedure but one that if expected, recognised and correctly managed, should not result in adverse outcomes.

Comparative effects of nitric oxide inhibition on the coronary vasomotor responses to etomidate, propofol, and thiopental in anesthetized dogs.

We examined the hypothesis that the coronary vasomotor responses to etomidate (ETO), propofol (PRO), and sodium thiopental (STP) are mediated through contrasting effects on the resting nitric oxide (NO)-dependent vasodilator tone that opposes adrenergic vasoconstrictor activity in the intact dog. Circumflex flow (CxF) responses to randomized intracoronary microinjections (0.3 mL) of normal saline (NS), alkalinized saline (AS), intralipid (IL), adenosine (ADE, 17 micrograms), acetylcholine (ACh, 1.25 micrograms), ETO (6, 12, 60 micrograms), PRO (30, 60, 300 micrograms), and STP (75, 150, 750 micrograms) were quantified in eight isoflurane-anesthetized dogs with fixed ventricular rates (100 bpm). Injections were repeated during intravenous (IV) infusion (50 mg/kg + 1 mg.kg-1.min-1) of NG-nitro-L-arginine methyl ester (L-NAME). ADE and ACh transiently increased CxF to 305% +/- 20% (P < 0.001) and 310% +/- 29% (P < 0.001) of resting values, respectively. ETO had no effect, whereas PRO (300 micrograms) provoked small transient increases in CxF to 135% +/- 4% (P < 0.05) of control. Responses to STP (750 micrograms) were characterized by momentary decreases to 74% +/- 4% (P < 0.001), followed immediately by increases to 183% +/- 11% (P < 0.001) of resting values; NS AS, and IL had no effect. The momentary decreases with STP (750 micrograms) were significantly augmented during NO inhibition with CxF declining to 49% +/- 7% (P < 0.001) of resting values, whereas the secondary increase was unchanged. With L-NAME, CxF responses to ACh were attenuated to 32% +/- 3% (P < 0.001) of control, whereas responses to ADE, ETO, and PRO were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Costs, severity of illness and outcome in intensive care.

Severity of illness (Therapeutic Index Severity Score, Classes 1-4) and direct clinical costs (labour costs, diagnostic costs, drugs, disposables, etc.) were determined for 100 consecutive patients admitted to Royal Newcastle Hospital Intensive Care Unit over six weeks. Outcome was assessed using mortality, quality of life, functional status, productivity and mental status one month after separation from the Unit. The mean total admission cost was $1,357 (Class 4 mean = $3,706) but for over 70% of patients costs were less than $1,000. The main component of cost was labour (about 60% for all classes). TISS proved a strong predictor (P less than 0.001) of total admission costs. Survival to one month was 89% and optimal association between cost and survival was found with those with low costs more likely to survive (P less than 0.001). On the other hand, no association was found between total admission cost and resulting quality of life. However, there was an association between pre-admission and follow-up quality of life (P less than 0.0005).

Post-operative respiratory failure due to bilateral phrenic nerve palsy.

A 65 year old female patient developed a large left pleural effusion and a sternal split dehiscence following aorto-coronary artery bypass grafting. A second operation was performed to investigate and drain the pleural effusion and to repair the sternum. Subsequent to this operation the patient was in acute respiratory failure due to bilateral phrenic palsy. It is probable that the left phrenic nerve was damaged in the initial operation and the right nerve in the second. The patient's subsequent progress is described.