Experimental intracerebral haematoma in the rat: sequential light microscopical changes

In a small animal model of controlled intracerebral haemorrhage, changes within the haematoma and surrounding tissues were examined by light microscopy in toluidine blue stained semithin sections. Groups of animals were killed at 2, 6, 15, 24 and 48 hours, 2, 4, 8 and 14 days, and 3 months survival. Sequential changes in neurons, glia and leucocytes, together with the gradual absorption of the blood clot and its replacement by an astrocytic scar are described.

Should we tell them when their blood pressure is up?

We carried out two studies to determine the effects of feedback on subsequent blood pressure and heart rate readings in subjects without significant cardiovascular abnormalities. In both studies the subjects were randomly assigned to be told that their blood pressure was normal or was high or to receive no feedback at all; 3 minutes later another reading was taken and correct feedback provided. Study 1 was done in 114 patients who attended a family practice teaching unit for an office visit; subjects taking cardioactive medication or with chronically elevated blood pressure (diastolic pressure more than 95 mm Hg) or known low pressure (diastolic pressure less than 60 mm Hg) were excluded. Half of the subjects received feedback from a nurse and the other half from a physician. We found no effect of type of feedback or type of practitioner on subsequent readings. No adaptation of diastolic blood pressure or heart rate took place, whereas a similar rest period in the laboratory consistently triggers cardiovascular adaptation. Given the field nature of the study it was not clear whether the intervention was not powerful or whether the practitioner-patient interactions diffused the effects of an otherwise powerful intervention. Therefore, a second study with the same design was carried out in a controlled laboratory setting with 61 university students who believed they were in the adaptation phase of an experimental stress protocol. The subjects did not interact with the experimenter, who provided only the initial feedback, via intercom. The findings replicated those of study 1: type of feedback had no significant effect on subsequent blood pressure levels, and all types of feedback prevented cardiovascular adaptation. We recommend that patients be allowed to rest alone for at least 10 minutes before blood pressure is measured. Our findings suggest that practitioners need not be concerned about telling normotensive or borderline hypertensive patients that their blood pressure is elevated.

The use of in vitro magnetic resonance tissue studies to optimise pulse sequences in the imaging of intracranial haemorrhage

The choice of appropriate MR pulse sequences to highlight a particular pathology to best advantage is not always straightforward. In this study of intracranial haemorrhage, tissue relaxation times measured in vitro were entered into a computer program which calculated the signal intensity of each tissue (brain, blood, CSF, and bloody CSF) for all possible echo (TE) and repeat (TR) times. Analysis of graph plots of the results enabled the selection of pulse sequences which gave optimal separation of the signal intensities of intracranial haemorrhage from those of normal intracranial contents. The sequences thus chosen were used successfully in the imaging of patients with intracranial haemorrhage.

Magnetic resonance imaging of acute subarachnoid hemorrhage

The feasibility, safety, and diagnostic value of magnetic resonance (MR) imaging versus computerized tomography (CT) scanning were compared in 30 patients with clinical evidence of subarachnoid hemorrhage. Subarachnoid blood was identified more often and more information was available about the site and source of the hemorrhage on MR imaging than on CT. Magnetic resonance imaging could be used safely both before and after the operation, provided that nonferromagnetic clips were used and that comprehensive monitoring and cardiorespiratory support were available. Postoperative studies showed that artifacts from metallic implants and from patient movement caused less image degradation on MR images than on CT scans.

Magnetic resonance imaging in acute head injury

Using cardiorespiratory monitoring and support equipment compatible with a low field (0.15 T) system, magnetic resonance imaging (MRI) of patients suffering acute head injuries proved to be both feasible and safe. An abnormality was demonstrated by magnetic resonance imaging in 46 of 50 patients examined within 7 days of head injury using T2 weighted (SE2200/80) and T1 weighted (IR2000/600/40) multislice sequences. IN contrast, computed tomography (CT) demonstrated abnormalities in only 31 of the 50 patients. Intracranial extracerebral space-occupying collections of blood were well shown by magnetic resonance imaging which provided especially clear definition in the posterior fossa, subtemporal and subfrontal regions. Magnetic resonance imaging was more sensitive to cerebral abnormalities associated with traumatic unconsciousness and detected parenchymal lesions both in patients in coma and in those who had lost consciousness for only a few minutes. Lesions seen with MRI but not with CT included non-haemorrhagic contusions and abnormalities thought to reflect shearing injuries of white matter and intracerebral vessels. Magnetic resonance imaging is an effective alternative to CT; the additional information it can provide should be valuable in increasing the understanding of the early effects and late consequences of a head injury.

Dipyridamole: pharmacokinetics and effects on aspects of platelet function in man

1. The effect of dipyridamole on platelet function was measured in twelve normal subjects given 150 or 200 mg tablets as single and multiple doses, and in six subjects given single doses of 25, 50 and 100 mg and multiple doses of 50 mg 8 hourly. 2. Platelet aggregation was measured in response to ADP and collagen. In the subjects given 150/200 mg, the platelets were assayed for content of cyclic AMP and for formation of thromboxane after addition of collagen. The responses to ADP and collagen and the cyclic AMP content were assessed in both the presence and absence of added PGE1. The pharmacokinetics of dipyridamole were studied in all subjects. 3. One hour after 150/200 mg single doses of dipyridamole there was significant inhibition of platelet aggregation in response to both collagen and ADP. There was no detectable effect on aggregation at other time points or with lower doses of dipyridamole. The addition of PGE1 to platelets prior to testing did not enhance the effect of dipyridamole on platelet aggregation. 4. In multiple doses, dipyridamole (150/200 mg twice daily for 11 days) had no detectable effect on platelet aggregation. 5. Dipyridamole did not have any effect on platelet cyclic AMP content, whether or not PGE1 was added prior to assay. 6. Dipyridamole did not affect platelet thromboxane formation. 7. Plasma dipyridamole concentrations were maximal 1-2 h after ingestion, at the same time that inhibition of platelet aggregation was detected. The concentrations declined in a biexponential fashion, with a terminal half life of 24.1 +/- 1.9 h (mean +/- s.e. mean). In six of the 17 subjects, the mean steady state plasma concentration was less than 75% of the value predicted from the single dose data.

Effects of experimental intracerebral hemorrhage on blood flow, capillary permeability, and histochemistry

Experimental intracerebral hemorrhage has been shown to cause extensive cerebral ischemia. This study was performed to ascertain the time course of these changes and also to examine the type of brain damage that may occur under such circumstances. Halothane anesthesia was induced in rats, and 25 microliter autologous blood was injected into the caudate nucleus; the effects were studied with autoradiographic measurement of local cerebral blood flow and capillary permeability, and also by light microscopy and histochemical techniques. Blood flow returned to normal or to slightly increased levels within the first 3 hours, and ischemic levels of flow were found to persist only to a marginal degree beyond 10 minutes after the lesions were made. Capillary permeability was maximum during the first 30 minutes after the hemorrhage and diminished with time. Structural evidence of ischemic damage was localized to the cortex overlying the hemorrhage, but was not seen in the caudate nucleus. Nevertheless, histochemical investigation did reveal an area of disturbed enzyme function in the striatum. This finding of biochemical disturbance without structural evidence of ischemic damage reveals that there is an area around the hematoma that, although demonstrating disturbed function, does not show structural damage, and the milieu of this partially injured brain may be implicated in the delayed development of the ischemic brain damage that follows intracerebral hemorrhage in man.

MR relaxation times of cerebrospinal fluid

A review of 15 recent publications purporting to provide the relaxation times of CSF reveals a considerable disparity in the quoted results, by a factor of five in terms of T1 (range 1,000 to 5,500 ms) and by a factor of 16 for T2 (range 166 to 2,640 ms). In this article measurements are performed independently on both a spectrometer and an imager. The results indicate that for CSF T1 is greater than 3,000 ms and T2 is approximately 2,000 ms at 6 MHz. The vast differences in relaxation behaviour between CSF and other body tissues have considerable clinical implications and present profound diagnostic opportunities. The application of this knowledge to ventriculography, myelography, and image contrast methodology is discussed.

The effect of 1 alpha-hydroxyvitamin D3 on the mineralization defect in disodium etidronate-treated Paget's disease--a double-blind randomized clinical study

A double-blind randomized study of 29 patients with symptomatic Paget's disease was conducted comparing the clinical, biochemical, and histomorphometric responses to 3-month treatment with placebo (10 patients), low-dose disodium etidronate (EHDP) (5-7 mg/kg/day) (10 patients), and low-dose EHDP plus 1 alpha-hydroxyvitamin D3 (1 alpha D3) 0.5 mcg daily (9 patients). In placebo-treated patients no significant changes were observed in symptoms, biochemistry, or bone histomorphometry. Histologically apparent mineralization defects developed after 3 months of therapy in 90% of patients in the EHDP group, compared with 45% of patients in the EHDP/1 alpha D3 group. In 19% of the patients treated with active medication, the mineralization defects in pagetic bone were accompanied by histological evidence of continued osteoclastic resorption. The development of mineralization defects was not related to serum levels of vitamin D metabolites, alkaline phosphatase, or intestinal calcium absorption but did correlate with the occurrence of hyperphosphatemia during treatment, which was most marked in patients treated with EHDP alone. Although mineralization defects were less frequent in the EHDP/1 alpha D3 group, these patients also responded less well symptomatically, thus limiting the potential usefulness of this drug combination in Paget's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Accuracy of stereotaxic localisation using MRI and CT

The accuracy of stereotaxic coordinates determined using the Leksell apparatus with CT and MRI was investigated using an Agar filled head phantom. Both imaging techniques were found to produce an accuracy of better than 2 mm with the exception of the Z coordinate as measured by CT (2.3 mm). This latter error is greater because of the 3 mm slice width used. Direct coronal views were used to determine Z more accurately using MRI. The measurement procedures are described and it is shown that the Leksell system of using orthogonal coordinates enables the scaling of images, which is particularly necessary with MRI, to be done easily.

Extracorporeal shock wave lithotripsy: interventional radiologic solutions to associated problems

Among 1,500 patients treated with extracorporeal shock wave lithotripsy, 1,300 had calculi less than 2.5 cm in diameter and 200 had calculi of 2.5 cm or larger. Although most patients did well and required no further radiologic intervention, 178 interventional radiologic procedures were performed. Urinary tract obstruction often developed in patients with large stones when the collecting system filled with stone fragments (steinstrasse). Nephrostomy was performed in 5.3% of the total patient population and in 29% of the patients with stones measuring 2.5 cm or more. Only 1.8% of the patients with calculi smaller than 2.5 cm required radiologic intervention. When the obstructed collecting system could not be crossed with conventional angiographic techniques, the stone fragments were removed through a percutaneous nephrostomy tract either by flushing or by suctioning with a pulsating water jet.

Early hemodynamic changes in experimental intracerebral hemorrhage

A model of experimental intracerebral hemorrhage is described in which carefully controlled volumes of autologous blood were injected at arterial pressure into the caudate nucleus of the rat. A comparison of intracranial pressure changes and local cerebral blood flow (CBF) was made between three groups of rats, each receiving different injection volumes, and sham-operated control rats by monitoring intraventricular pressure and by obtaining quantitative autoradiographic measurements of CBF within 1 minute of the experimental hemorrhage. Cerebral blood flow was reduced both around the hematoma and in the surrounding brain. This change was strongly volume-dependent and was not accompanied by significant alterations in cerebral perfusion pressure. This finding suggests that the degree of ischemia at the time of an intracerebral bleed depends on the size of the lesion, and implicates local squeezing of the microcirculation by the hematoma, rather than a generalized alteration in perfusion pressure, as the cause of ischemia.

Digital mapping of multi-parameter contrast functions in magnetic resonance (MR) imaging using a standard MR computer system and digital display

A technique is described which utilises the full analysis and display capabilities of a commercial MRI system to produce digital maps of multi-parameter functions produced by MR contrast theory. The technique is utilised to determine the effects of nominating specific overall scan times on the optimum solutions as produced by the theory and it is shown that different solutions are obtained when the theory is applied using typical clinical constraints. The digital mapping approach is potentially of great value in prospectively determining pulse timing parameters to produce optimum contrast images, in producing contrast maps to aid retrospective image interpretation, and as a training aid for clinicians inexperienced in the interpretation MR images.

Comparison of two high dose corticosteroid aerosol treatments, beclomethasone dipropionate (1500 micrograms/day) and budesonide (1600 micrograms/day), for chronic asthma

Twenty eight patients with chronic asthma took part in a double blind single crossover controlled trial of inhaled budesonide and inhaled beclomethasone dipropionate, using high doses of 1600 micrograms and 1500 micrograms daily respectively. Both drugs were administered by pressurised aerosol inhaler; the inhaler containing budesonide and its matching placebo were fitted with a collapsible spacer device. There was no significant difference in the control of asthma during the two six week treatment periods. There was no significant difference in FEV1 and forced vital capacity after four and six weeks of treatment or in mean morning and evening peak expiratory flow rates for the last 21 days of treatment. There was a small but statistically significant reduction in the daytime wheeze score while they were taking high dose budesonide but there was no difference for daytime activity, cough, and night symptoms. The mean basal cortisol concentrations were significantly lower after six weeks of high dose treatment than before treatment (budesonide p less than 0.01, beclomethasone p less than 0.05). There was no difference between mean basal cortisol values after six weeks of high dose treatment, and there was no effect on the rise of cortisol obtained after a short tetracosactrin test. High dose inhaled corticosteroids produced few side effects and were well tolerated.

A quantitative index of ventricular and extraventricular intracranial CSF volumes using MR imaging

A new technique is described that utilises a novel magnetic resonance pulse sequence to produce a quantitative index both for ventricular and, for the first time, extraventricular intracranial CSF volumes. The pulse sequence is a combination of a null-point inversion recovery sequence with an extended spin-echo read (echo time = 400 ms), which produces a contrast of CSF to white or grey matter of approximately 120:1. A series of experiments are performed on phantoms representing CSF filled ventricles and sulci over a wide range of volume values, and it is found that the standard deviation of differences between true and estimated values is 3.9% for ventricles, 4.6% for total cranial CSF, and 7.9% for CSF within the sulci. Normal volunteer reproducibility studies revealed corresponding standard deviations of less than 5.5%. Using the technique to produce absolute estimates of CSF volumes in normal subjects and patients produced results in good agreement with previously published necropsy studies. The technique has wide neurological and neurosurgical applicability particularly in terms of differential diagnosis and as an objective monitor of therapy or progression in conditions such as hydrocephalus, atrophy, and benign intracranial hypertension.

Brain lesions detected by magnetic resonance imaging in mild and severe head injuries

50 patients were studied by magnetic resonance imaging (MRI) within one week of a head injury. Abnormalities indicating primary brain damage were found in 46 patients, almost twice as many as with computed tomography. Cortical contusions were the most common finding, irrespective of the effect of injury on the level of consciousness. Intracerebral lesions were seen only in patients who had lost consciousness and were present in 29 of 42 patients whose consciousness was still impaired on arrival at hospital. Lesions in the deep white-matter of the cerebral hemispheres were seen in 15 patients; they were significantly more frequent in patients in coma but were also seen in patients who had lost consciousness for no more than 5 min. The findings indicate that lesions in the cerebral hemispheres may be the primary factor in traumatic unconsciousness. MRI studies may also clarify the sequelae of head injuries.

Making a rehabilitation hospital for the elderly work

We report our efforts to make a rehabilitation hospital work. The simple intervention of introducing a patient record system, in which problems, management, achievements and discharge plans were clearly documented, doubled the number of patients who returned home over an eight-month period. This resulted in greater availability of acute geriatric beds at the District General Hospital (DGH), where two thirds of the elderly medical inpatients occupy beds on other units, and in an improvement in morale of patients and staff. Greater co-operation between geriatric and medical teams in selecting those patients who would benefit from continuing rehabilitation is required. The advantages of accommodating such patients separately from patients with a poor prognosis and those requiring long-term care are discussed.

Does insulin administration contribute to immune complex formation in diabetes?

The effect of insulin administration on immune complex (IC) formation in diabetic patients was analysed in vivo and in vitro. Firstly, serial studies of IC status were performed over a mean period of 18 months in 44 diabetic patients, 37 of whom were receiving standard insulin therapy. Thirty patients changed to monocomponent (MC) insulin while seven commenced MC insulin after tablet failure. The other seven patients remained on standard insulin throughout the study. Secondly, nine patients had serial measurements of IC over a 6-8 h period following a routine morning dose of MC insulin; eight control subjects were similarly studied. The insulin content of IC in insulin treated patients was assessed in vitro by examining, (a) the selective precipitation of antibody bound insulin by 3% polyethylene glycol (PEG) and (b) the insulin specificity of antisera raised against PEG precipitates of IC positive sera. The longitudinal study of circulating IC showed no significant changes apart from an isolated fall in IgA containing IC at 6 months after changing therapy (P less than 0.05). No short term change in IC was observed after MC insulin administration. The precipitability of antibody bound insulin in insulin treated patients was not significantly different to that seen in non-insulin treated patients or normal sera. Antisera to PEG precipitates of diabetic sera showed no significant specificity for insulin, although they showed marked reactivity with other plasma components (such as immunoglobulins and complement components). It is concluded that administered insulin plays little or no role in IC formation in insulin treated diabetic patients.

PTH and vitamin D responses during treatment of hypomagnesaemic hypoparathyroidism

The response of calcium regulating hormones in a patient with hypomagnesaemic hypoparathyroidism was assessed during magnesium infusion. Magnesium repletion was accompanied by prompt restoration of PTH secretion which subsequently stimulated 1,25-diOHD3 production, thus correcting hypocalcaemia. Further, failure of the patient to respond to previous 1 alpha-OHD3 therapy suggests that severe magnesium depletion may also result in a state of acquired resistance to the active metabolites of vitamin D.

The instep of the foot as a fasciocutaneous island and as a free flap for heel defects

The instep flap needs neither muscle nor a transposition base for survival or innervation. It can be transposed as an island fasciocutaneous flap either on the medial or lateral plantar neurovascular bundles or both, and it can be transferred also as a free flap from the opposite foot. Four cases demonstrating the use of the flap as an island and free flap are presented with follow-up ranging from 1 to 2 years. The absence of muscle in the flap provides greater stability of the heel reconstruction and results in a lesser secondary defect. Sensation in the flaps is diminished but adequate for long-term function, but hyperkeratotic reaction remains an unpredictable problem. The ability to transfer the flap as a free transfer widens the scope of the flap to reconstruct both heel and forefoot defects where local instep tissue or vascularity are inadequate for local reconstruction. The secondary defect, particularly when no muscle is included in the flap, has been minimal.

The effect of fermented and unfermented milks on serum cholesterol

Groups of 10 to 13 healthy volunteers were provided with 11 supplements of 2% butterfat milk (2% milk), whole milk, skim milk, yogurt, buttermilk, and sweet acidophilus milk daily for a 3-wk period. Despite increases in caloric intakes on all supplements, no significant increases were found in total, low-density, and high-density lipoprotein cholesterol. A significant weight gain was seen in subjects taking yogurt and acidophilus groups; these were the only two groups showing significant rises in triglyceride levels. These results in normal volunteers focus attention on the current practice of recommending only skim or 2% milk for hyperlipidemic individuals.

Effect of processing on digestibility and the blood glucose response: a study of lentils

To test the effect of processing on digestibility and the glycemic response to a leguminous seed, a group of eight healthy volunteers took a series of breakfast test meals containing either lentils which had been processed in four different ways or the same amount of carbohydrate as white bread. Lentils, boiled for 20 min, resulted in a flattened blood glucose response by comparison with bread. This was unaltered by blending the lentils to a paste or boiling them for an additional 40 minutes. However the blood glucose response was significantly enhanced by drying the boiled blended lentils for 12 h at 250 degrees F. In vitro digestion with human saliva showed the rate of sugars released from the food related positively to the blood glucose rise. Breath hydrogen studies indicated that carbohydrate malabsorption was too small to account for differences in the blood glucose response. These results emphasize the importance of processing in determining digestibility and hence the glycemic response to a food.

Generation of fecal and total coliform surges by stream flow manipulation in the absence of normal hydrometeorological stimuli

The response of Escherichia coli and total coliform concentration to increases in river discharge was investigated. Artificial hydrographs were generated on eight occasions between 21 October 1979 and 3 March 1981 by releasing water from Thruscross Reservoir in North Yorkshire into Fewston Reservoir. The majority of the releases were made after rainless periods to isolate the effects of stream channel entrainment from those induced by rainfall on the land surface. In the absence of rainfall, bacterial concentrations are shown to increase more than 10-fold in response to stage increases. It is suggested that two stores of bacteria must exist on the catchment, the first being a land store and the second a channel or near-channel store. Movement from the land to the channel store must relate to hill slope hydrological processes, whereas movement between stores in the channel fluvial system may be closely allied to sedimentary processes. Some consideration is given to bacterial levels in relation to European Economic Communities guidelines for contact recreation.

Cigarette smoking among secondary schoolchildren in 1975. Prevalence of respiratory symptoms, knowledge of health hazards, and attitudes to smoking and health

A questionnaire relating to smoking habits, respirator symptoms, and health attitudes was administered to 10 498 secondary schoolchildren in 1975. The results reported in this paper indicate that children who smoke regularly have a higher prevalence of upper respiratory tract infections and a higher incidence of the respiratory symptoms, cough, phlegm production with a cold, and shortness of breath, compared with non-smokers. Children are aware of the risks of lung cancer when smoking, but less aware of the other more immediate health risks, and this is particularly so in the younger age groups. It is suggested that health education should be directed towards younger children and that more use should be made of the fact that smoking clearly makes them less healthy.

A mammalian nicking endonuclease

Purification and properties are described for an endonuclease isolated from calf thymus which attacks double-stranded, unmodified DNA, primarily by making single-strand breaks. No detectable acid-soluble products arise from the reaction. Double-strand breaks may occasionally be produced by the introduction of single-strand breaks on opposite strands in close proximity. The enzyme does not attack denatured DNA and is not inhibited by tRNA. Although added divalent cations are not required for activity, the enzyme is inhibited by EDTA, which suggests an essential role for bound cations; reaction is inhibited by Ca2+. The endonuclease has a broad pH optimum and is inactivated by preincubation at temperatures of 45 degrees C and higher. The molecular weight as determined by gel chromatography is about 30 000. Analysis of the products of reaction on a defined substrate, bacteriophage T3 DNA, by sedimentation in alkaline sucrose density gradients indicates limit products with chain lengths of about 0.8 X 10(6) daltons. On electrophoresis in agarose gels these products were shown to be heterogeneous in size. The endonuclease appears to generate 3'-hydroxyl and 5'-phosphate ends. The ability of the endonuclease to utilize bovine DNA as substrate argues against a restriction role for this enzyme.

Repair of ultraviolet light-induced damage in Micrococcus radiophilus, an extremely resistant microorganism

Repair of ultraviolet radiation damage was examined in an extremely radioresistant organism, Micrococcus radiophilus. Measurement of the number of thymine-containing dimers formed as a function of ultraviolet dose suggests that the ability of this organism to withstand high doses of ultraviolet radiation (20,000 ergs/mm2) is not related to protective screening by pigments. M. radiophilus carries out a rapid excision of thymine dimers at doses of ultraviolet light up to 10,000 ergs/mm2. Synthesis of deoxyribonucleic acid is reduced after irradiation, but after removal of photodamage the rate approaches that in unirradiated cells. A comparison is drawn with Micrococcus luteus and M. radiodurans. We conclude that the extremely high resistance to ultraviolet irradiation in M. radiophilus is at least partly due to the presence of an efficient excision repair system.

Flatulent dyspepsia: a tiered symptom complex?

The symptom complex of flatulent dyspepsia is ill-defined but is made up of at least nine individual symptoms. The relationship between these symptoms is not known and thier change after cholecystectomy in gall-stone patients is unpredictable; they disappear completely in less than half the patients. We studied the symptoms in one hundred and thirty nine patients, using various computer programmes to see if the changes after operation could be predicted and if some of the symptoms were linked or formed "clusters". The results did not show any standard relationship between the symptoms. We have therefore, proposed the hypothesis of a tiered symptom complex to explain these observations. They could be produced by a motility disorder affecting different parts of the gastro-intestinal tract to a varying degree.