Human bite injury in North East England--the impact of alcohol intake on a mode of violent assault.

Ninety-two retrospective cases of human bite injury referred to a Plastic Surgery department are presented. Particular emphasis is placed on the relationship of alcohol intake to these injuries, their distribution and subsequent management. A review of the literature is conducted. The human bite is a leisure time injury of the young single male in the North East. It has been shown that there is a clear link to alcohol and in particular weekend drinking. Prompt operative intervention and wounds located at the head and neck have been shown to be associated with a decreased risk of subsequent infection, which reflects findings in the earlier literature. Fifteen cases were infected. One was the result of a postoperative complication. The remainder were infected on admission. The majority of infected cases were upper limb bites and were associated with a delayed presentation.

Effect of hydration on plasma volume and endocrine responses to water immersion.

To determine the effect of hydration on the early osmotic and intravascular volume and endocrine responses to water immersion the hematocrit, hemoglobin, plasma renin activity (PRA), and plasma electrolyte, aldosterone (PA), and vasopressin (PVP) concentrations were measured during immersion following 24-h dehydration; these were compared with corresponding values following rapid rehydration. Six men and one woman (age 23-46 yr) underwent 45 min of standing immersion to the neck preceded by 45-min standing without immersion, first dehydrated, and then 105 min later after rehydration with water. Immersion caused an isotonic expansion of the plasma volume (P less than 0.001), which occurred independently of hydration status. Suppression of PRA (P less than 0.001) and PA (P less than 0.001) during both immersions also occurred independently of hydration status. Suppression of plasma vasopressin was observed during dehydrated immersion (P less than 0.001) but not during rehydrated immersion. It is concluded that plasma tonicity is not a factor influencing PVP suppression during water immersion.

Analysis of calcium-lipid complexes in faeces.

Calcium is purported to prevent colorectal cancer by forming insoluble complexes with bile acids and long-chain fatty acids in the large bowel. Therefore, a method for analysing calcium-lipid complexes in faeces has been developed to investigate this. The calcium soaps of a long-chain fatty acid (calcium palmitate) and bile acids (calcium deoxycholate, chenodeoxycholate, cholate and lithocholate) were obtained by organic synthesis. Studies with the authentic soaps reveal that they exist in an empirical ratio of calcium-to-lipid of 1:2. On addition to lipid-free faeces, approximately 30% of calcium palmitate could be recovered and quantified in the authentic state by extraction with 72% ethanol and overnight precipitation at 0 degree C. In contrast, the calcium soaps of the bile acids could not be recovered in the authentic state but were quantified entirely as the free acids. The method was applied to the analyses of calcium-lipid complexes in the faeces of adenoma patients partaking in a placebo-controlled calcium-intervention study. The results show that human faeces contain appreciable amounts of calcium long-chain fatty acid soaps predominantly in the form of calcium palmitate and stearate. The faecal concentration of long-chain fatty acid soaps was increased significantly (P = 0.005) during calcium intervention but this did not have a statistically significant effect on the excretion of free long-chain fatty acids (P = 0.4). Calcium long-chain fatty acid soap formation was found by multiple regression to be equally dependent on stool long-chain fatty acid and calcium concentration. Calcium soaps of the bile acids were not detected by this method.(ABSTRACT TRUNCATED AT 250 WORDS)

Athletes, astronauts and orthostatic tolerance.

Specific alterations in autonomic functions induced by endurance training may lead to a reduced ability to withstand orthostatic stress. This possibility has caused some authorities to suggest that, because of potentially greater pooling of blood in the lower extremities during gravitational loading, endurance-trained athletes may make poor astronauts. Although results from spaceflight studies have provided little evidence to support this suggestion, data from water-immersion studies indicate that endurance-trained athletes do become more orthostatically intolerant following a few hours of simulated weightlessness. Unfortunately, other evidence supporting the hypothesis that endurance training reduces orthostatic tolerance has not received adequate publication in the open scientific literature. On the other hand, a number of studies which have been openly reported clearly refute this hypothesis. Nevertheless, the established physiological differences between endurance athletes and non-athletes are themselves sufficient to suggest that the hypothesis could be tenable. Consequently, it has to be concluded that the presently available information is both qualitatively and quantitatively inadequate to permit any definite statement regarding a possible relationship between aerobic power (VO2max) and orthostatic tolerance.

Heat and exercise. Effects on blood volume.

The ability of the cardiovascular system to meet the competing demands of skin and muscle for blood flow without compromising regulation of blood pressure is a critical factor influencing the capacity for prolonged work in hot environments. Unfortunately, this competition is exacerbated by the progressive reduction in blood volume (haemoconcentration) which can occur during exercise in the heat. Thermal stress alone induces haemoconcentration only above the upper limit of the prescriptive zone. Exercise performed in a supine or seated position is associated with an initial rapid haemoconcentration, which, if the environmental temperature is high, is followed by a slower, secondary haemoconcentration. Exercise performed in a standing position is associated with variable changes in blood volume, and effects of a superimposed thermal stress are small unless dehydration supervenes. The magnitude of exercise-induced primary haemoconcentration is limited, probably by oedema-preventing mechanisms, and is inversely related to the magnitude of any preceding postural haemoconcentration. Dehydration reduces absolute blood volume (induces hypovolaemia), and accentuates exercise haemoconcentration. Heat acclimatization attenuates dehydration by inducing hypervolaemia, but still appears to accentuate exercise haemoconcentration. During exercise in the heat haemoconcentration represents an undesirable response, the effects of which can be mitigated by heat acclimatization, endurance training, and preventing dehydration.

Intravascular volume and protein responses to running exercise.

The roles of posture and mean skin temperature (Tsk) in determining intravascular volume and protein responses to running exercise were examined in 12 male subjects. Moving from a sitting to a standing position before exercise was always accompanied by a decrease in blood volume (BV), as indicated by increases in the hematocrit and hemoglobin concentration. Although neither the onset of running nor alterations in Tsk during running caused any further consistent change in BV, there was an acceleration of the rate at which protein entered the intravascular space. At the end of exercise and in recovery this led to an augmentation of intravascular protein. It is concluded that intravascular volume responses to running exercise are determined by the accompanying postural hemoconcentration, and that running per se and any imposed thermal stress have minimal effects on BV thereafter. A hypothesis is presented which accounts for the reportedly diverse effects of different forms of exercise on BV in terms of the posture-dependent BV being obtained immediately before exercise begins.

Painful sequelae of coxa plana.

Thirty-one patients with an average age of twenty-seven years had painful hips as the result of coxa plana in childhood. The pain was severe enough for surgical relief to be considered. Radiographically the lesions could be subdivided into three groups: severe mushroom deformity of the femoral head, 43 per cent; less severe dysplasia of the hip, 27 per cent; and severe osteoarthritis, 30 per cent. Twenty-three hip operations were done on theses patients. Fifteen hips showed radiographic evidence of definitive premature closure of the femoral capital epiphysis. The series is presented to illustrate that coxa plana may be followed by major disability in the hip within the first three decades of life.

Coxa plana--the fate of the physis.

Eighty patients who had unilateral coxa plana and who had been treated conservatively were followed to a mean age of sixteen and one-quarter years, and their cases were reviewed for radiographic evidence of a disturbance of the femoral capital growth plate. This physeal involvement was inferred by the presence of one or more of five findings: premature physeal closure, overgrowth of the greater trochanter, change in physeal shape, lateral protrusion of the capital nucleus, and medial bowing of the femoral neck. Premature physeal closure, which was more common in the girls than in the boys, occurred in 25 per cent of the affected femoral heads, and 90 per cent of the patients showed some interference with normal physeal growth in the affected femoral head. A direct correlation was found between the severity of the physeal involvement and the ultimate deformity of the femoral head. The possible causes of interference with physeal growth and damage are discussed.

A prospective study of children with untreated Catterall group 1 Perthes' disease.

Twenty-four hips in twenty children affected by Group 1 Perthes' disease have been reviewed to assess the radiographic result after a minimum follow-up of four years. The children were allocated to Group 1 prospectively after examination of the early radiographs and no specific treatment of the affected hip was provided. The radiographic end results assessed by three methods were good even in those cases in which the additional stress of containment splintage of the contralateral hip was applied.

The correction of angular deformities of long bones by osteotomy-osteoclasis.

The correction of angular deformities of long bones by incomplete osteotomy, followed three weeks later by manual osteoclasis, overcomes the problem of secondary displacement sometimes seen after correction by complete osteotomy and makes internal fixation unnecessary. This paper presents an experience of twenty-six operations in eighteen patients. In all cases the deformity was corrected with excellent cosmetic and functional results. Complete bony union was achieved and there were no problems with displacement at the osteotomy site. Four cases are described in detail to illustrate use of the technique in different clinical situations.

A study of the "normal" hip in children with unilateral Perthes' disease.

The radiographs of 153 children suffering from Perthes' disease of one hip were studied to examine the bony outline of the femoral capital epiphysis in the unaffected hip. In 48.4 per cent of patients irregularity of the surface, flattening or dimpling, were noted; in the majority of instances (37.2 per cent) these changes were present in the initial anteroposterior radiograph. By contrast, these changes were present in only 10.4 per cent of a control series of 153 children in whom intravenous urography was being performed, these children being matched for age and sex with the children with Perthes' disease. A second unmatched control series of 49 children whose pelves were being radiographed after injury showed a 6.1 per cent incidence of contour irregularities in 98 femoral capital epiphyses. In the patients with Perthes' disease and in the control series obtained at urography the incidence of changes was inversely related to age. The possible cause and significance of contour irregularities in normal children and in those with Perthes' disease is disscussed.

Slipped upper femoral epiphysis. A potential for spontaneous recovery.

Evidence is presented to support the contention that after slipping of the upper femoral epiphysis there is a potential for the bony epiphysis to grow back to its pre-slipped position. A suggestion is made as to how this recovery may occur.

The sagging rope sign: a critical appraisal.

Certain features of the sagging rope sign recently analysed by Apley and Weintroub (1981) are examined in detail. Evidence is presented to show that the line is a radiological shadow cast by the lateral edge of a severely deformed femoral head rather than a condensation of the spongiosa within the neck. An explanation is offered to explain the common association of the presence of this radiological sign with premature epiphysial fusion.

Skeletal immaturity in Perthes' disease.

Skeletal age was estimated by examination of radiographs of the carpus in 182 children suffering from Perthes' disease after the reliability of the Greulich and Pyle Atlas had been checked for a control group of British children. A striking tendency to delayed skeletal maturation was shown in the children with Perthes' disease. This trait was also found in ninety-three unaffected siblings of the patients. The velocity of skeletal ageing as the disease progressed was estimated. In some patients the carpal skeleton failed to mature at all for periods of up to three years and the term "skeletal standstill" is applied to this phenomenon. The significance of these findings is discussed and it is suggested that the maturation defect may have aetiological significance.

Congenital abnormalities and Perthes' disease. Clinical evidence that children with Perthes' disease may have a major congenital defect.

This paper reports a high incidence of minor congenital anomalies in boys and girls with Perthes' disease compared with that in a control population. There is a similarity of the incidence of minor anomalies in the children with Perthes' disease to that in babies with a single major congenital defect. Multiple major defects were more numerous and more severe than in the control children. It is speculated that there may be a congenital abnormality affecting skeletal development which in some way makes the hip susceptible to Perthes' disease at a later date.

Effects of acute heat stress on tissue carbohydrate in fasted rats.

Exposure of starved female rats to 45 degrees C db, 26 degrees C wb for 0.25-2 h tended to lower blood glucose levels, and increase blood lactate levels, compared with controls at 24 degrees C db, 14 degrees C wb. There was a sustained liver glycogenolysis, but no detectable change in muscle glycogen level. Despite the severity of the stress, the effect of a high environmental temperature on carbohydrate metabolism cannot be satisfactorily interpreted in terms of increased adrenal medullary activity. It is suggested that increased respiratory muscle activity may explain the changes observed.

Operational characteristics of liquid-conditioned suits.

The data from several studies of liquid-conditioned suits carried out over the last 12 years at the RAF Institute of Aviation Medicine have been collated, collectively reanalysed, and used to describe the characteristics of personal liquid-conditioning systems in terms of interactions between the conditioning and the conditioned system. Heat exchange across a liquid-conditioned suit (LCS) is shown to be proportional to the inlet temperature (Tin) of the conditioning liquid. Choice of Tin is determined, for resting subjects, primarily by the environmental temperature, by the length of the heat exchange tubing, and by the insulation value of the clothing worn over the LCS. Mean skin temperature (Tsk), but not core temperature (Tc) is directly related to Tin. However, certainly in exercising subjects, steady-state values for Tc can be increased by selecting very low values for Tin, which reduce Tsk below 29 degrees C. It is suggested that mean Tsk should not fall below 30 degrees C when the LCS is used for personal cooling. When the LCS is used for personal heating, sweating should be minimised, or prevented, by not allowing Tsk to rise to levels sufficient to cause an increase in Tc.

Heat stress in an aircraft cockpit during ground standby.

Measurements have been made of cockpit temperatures in a Buccaneer aircraft exposed to high air temperatures and radiation loads. With the canopy open 8 cm, and with the wind direction unfavourable for convective cooling, air temperatures inside the cockpit exceeded those outside by approximately 20 degrees C. This reduced to 10 degrees C with a favourable wind direction. An assessment of the likely heating effect of cockpit avionic equipment indicated that the addition of 1 kW and 2 kW of heat would raise cockpit temperatures by 20 degrees C and 30 degrees C respectively. Prediction of the combined effect of solar and avionic heat suggests that, in hot weather conditions, cockpit temperatures will be considerably in excess of the upper limit for effective physiological temperature regulation. Therefore, if aircrews are to be required to remain on ground standby within their aircraft under such conditions, maximum use must be made of convective cooling of the cockpit by the prevailing wind, and of sun shades to eliminate the greenhouse effect completely.

Measurement of change in plasma volume during heat exposure and exercise.

The application of radio-iodinated human serum albumin (RISA) to the measurement of a continuously changing plasma volume, such as that occurring during heat exposure and exercise, has been considered in terms of the exchange dynamics of albumin between the intravascular and extravascular compartments. In six male subjects resting supine for 2 h in a hot environment, or exercising for 50 min in a thermoneutral or hot environment, there was no statistically significant alteration in the rate of protein efflux from the intravascular space. However, following exercise, protein was added to the circulation at a greater rate than it was lost through the capillary walls. A technique for calculating plasma volume from a single measurement of plasma RISA activity is described. This may be used in conjunction with measurements of changes in haemoglobin concentration of determining plasma volume in situations where alterations in protein exchange dynamics do occur.

Identification of an apprehension effect on physiological indices of thermal strain.

A laboratory assessment of the thermal strain produced by wearing a protective clothing assembly, in addition to a normal flying clothing assembly, in a hot environment is described. In addition to the demonstration of an increase in thermal strain when wearing the protective clothing, two points of importance emerged. First, condition replication revealed a significant apprehension effect which confounded the physiological variables used to evaluate the thermal strain, leading to an over-estimation of the severity of that strain. Second, there was a large between-subject variation amongst the eight subjects used, which made the arithmetic mean a potentially misleading statistic for evaluating the increased physiological strain caused by the additional clothing assembly during the heat exposure. The practical implications of these observations are discussed....