Metabolic studies following thoracotomy for lung cancer with particular reference to postoperative atrial fibrillation.

Atrial fibrillation has proved to be a frequent complication after thoracotomy for lung cancer. In order to study the possibility that metabolic changes are the trigger mechanism of these arrhythmias, free fatty acids (FFA), glycerol, triglycerides, serum insulin and glucose were determined pre- and postoperatively in patients both with and without this postoperative complication. In the primary series of patients, FFA were found to be increased immediately after the start of the atrial fibrillation, partly in relation to the morning values and partly to the 24-hour curve. This is a possible expression of an increased lipolysis in a causal relationship to the arrhythmia. In another series of patients, the degree of lypolysis was demonstrated using the glycerol values. With this method, no signs of increased lipolysis were found in connection with the onset of atrial fibrillation. Thus, changes in the lipoid metabolism were not found to be the trigger mechanism of the postoperative atrial fibrillation. Reduced values of serum insulin and glucose were not demonstrated either during the uncomplicated postoperative period or at the start of atrial fibrillation.


Experimental evaluation of oesophageal muscular cuffs in the repair of oesophageal defects.

The current study was designed to test the value of oesophageal muscular cuffs in the repair of anastomotic defects in the thoracic oesophagus. In 30 piglets, defects involving 25%, 50% and nearly 100% of the anastomosis were created and repaired by means of a cuff derived from the oesophagus musculature. The results demonstrated that his method provides uniformly a leak-proof closure under the most severe circumstances. Oesophageal narrowing at the site of repair was common and depended on the nature of the experiment and not on the technique used. Although experimental data may not be directly transferable to human subjects, this method proved so effective that it might be the potential clinical benefit. Questionable oesophageal anastomoses and fresh oesophageal perforations are the clinical applications suggested.


Early results of heart valve replacement with the Björk-Shiley prosthesis.

The operation on and subsequent course of 88 patients with valve replacements using Björk-Shiley tilting disc prostheses has been reviewed in terms of mortality, clinical results, and valve function. The follow-up period varied between 6 months and 2 years. The hospital mortality was 17% and late mortality 8%. Of those who left hospital, 75% returned to full normal activity and required less (or no) drug therapy other than maintenance anticoagulation. There was one transient embolic episode. Significant intravascular haemolysis does not occur with this prosthesis.


"In situ" evaluation of the aortic pivoting disc valve prosthesis.

An index of the "in situ" forward flow characteristics of an aortic valve prosthesis is suggested. The effective area index, Ia, is defined as the ratio between the effective orifice area, Aeff, and the area occupied by the valve in the aortic root. Aeff is calculated from a hydraulic formula using peroperative measurements of instantaneous ascending aortic flow, Fao, and the pressure gradient, deltaP. Ia was found to be 0.29 +/- 0.33 (S.D.) for Lillehei-Kaster valves and 0.32 +/- 0.059 (S.D.) for Björk-Shiley valves. The variations in valve performance among the Björk-Shiley valves may partly be due to differences in valve orientation in the aortic root. Attention should therefore be given to the choice of the opening direction of the disc in order to optimize valve performance in the patient.


Aortic valve replacement with the Björk-Shiley tilting disc valve prosthesis. Clinical experiences in 50 cases.

Single aortic valve replacement with the Björk-Shiley tilting disc valve prosthesis has been performed in 50 patients since April 1971. None of the total of six deaths (12.0%) was attributable to malfunction of the prosthesis or to embolic complications. Follow-up examination showed insignificant or moderate prosthetic regurgitation in two patients and moderate paravalvular leakage in one patient. A slight intravascular haemolysis was found in two cases, one of them without marked regurgitation, and a slight reversible cerebral thrombo-embolism in two. Clinical improvement was observed in 43 of the 44 survivors during the 6 to 12 months of follow-up. Objective evidence of improvement was verified by cardiac catheterization following the replacement of aortic valve with the Björk-Shiley tilting disc prosthesis.


Emergency aortic valve replacement in active endocarditis with the Björk-Shiley tilting disc valve prosthesis.

Because of severe and intractable heart failure in three patients with infective endocarditis, an emergency replacement of the aortic valve with a Björk-Shiley prosthesis was carried out. Heart failure, which is the most common cause of death in infective endocarditis, was in these cases due to acute aortic regurgitation caused by perforation and other damage of the aortic valve. One patient died in the early postoperative period because of myocardial damage and respiratory insufficiency. The other two survived and are in relatively good condition after follow-up periods of 2 years and 6 months, respectively. The emergency replacement of incompetent valves may be a lifesaving procedure during the course of active endocarditis.


Aortic valve replacement with frame-supported autologous fascia lata grafts. I. Technical consideration and early results.

During the period November 1969 to June 1972, a frame-supported autologous fascia lata graft was implanted in 71 consecutive patients with surgically treated aortic valve disease at the Department of Thoracic & Cardiovascular Surgery, University Hospital, Uppsala. The follow-up period was between 1 and 4 years. Eleven patients died within 28 days of the operation (16%) and 13 after discharge from hospital (18%); the cumulative mortality was thus 34%. Forty-five percent of the patients who died had associated cardiovascular or other diseases. The causes of death were infection (10), myocardial failure (6), myocardial infarction (3), cerebral damage (3), and intraoperative aortic dissection from the cannulation site (2). The majority of the deaths (88%) occurred within 6 months and all within 13 1/2 months after operation. Two fascia lata valves were removed because of endocarditis 23 and 26 months, respectively, after operation. Two valves were also removed on account of mechanical malfunction. The remaining 44 patients with fascia lata valves had returned to work. No embolic complications occurred, despite the fact that only patients with a concomitant prosthetic mitral valve or atrial fibrillation received anticoagulatant treatment. Haemodynamic studies of the valve in vitro and pressure measurements during the operation showed that the valve had a low primary systolic peak gradient of 0-16 mmHg. Certain modifications in the construction aimed at improving the haemodynamic properties of the valve are discussed. Increased stringency in the sterility precautions during the valve construction procedure may have contributed to the fact that early endocarditis, which is a serious complication, did not occur in any of the last 43 patients. As yet the observation time is too short to judge, however, to what extent susceptibility to infection and possible late changes of the valve can affect its function.


Removal of trace levels of 2-acetylaminofluorene (2-AAF) from wastewater.

An adsorption system is described for the removal of part per billion levels of the chemical carcinogen, 2-acetylaminofluorene (2-AAF), from industrial wastewater. The system consists primarily of filters and activated carbon and non-ionic polymeric adsorbents arranged in tandem. It is highly efficient, operates at low cost, and requires minimal attention. The chemical monitoring of the raw and/or cleaned-up wastewater is based on a highly sensitive and specific spectrophotofluorometric method that allows acceptance or rejection of samples at the 0.2 part per billion level. The system is presented as a model for evaluating the removal of traces of organic chemicals from wastewater prior to recycling or discharging it into the environment. Results of laboratory evaluations of several other approaches to the purification of 2-AAF-containing wastewater are also presented.


A probabilistic model of bathing beach safety.

An improved mathematical model for bathing beach safety is proposed. It is derived by joining the probability of infection from a given dose (Poisson distribution and the probability of acquiring such a dose (lognormal distribution). Even in the absence of better clinical and epidemiological data, the model permits an assessment of relative risk from certain hazards and the design of more meaningful bacteriological standards for individual beaches.


Human alpha-lactalbumin: measurement in serum and in breast cancer organ cultures by radioimmunoassay.

A sensitive and specific radioimmunoassay for human alpha-lactalbumin, a major milk protein, is described. Some normal men and women have detectable levels of alpha-lactalbumin in their blood. High values are found in nursing mothers and many patients with galactorrhea. Alpha-Lactalbumin is found in some breast cancer organ cultures. In addition, alpha-lactalbumin output was stimulated by ovine prolactin in 2 of the 19 tumors studied.


Melatonin: antigonadal and progonadal effects in male golden hamsters.

Melatonin induced marked testicular regression in hamsters maintained on photostimulatory long days (light-dark 14 : 10). In animals maintained on nonstimulatory short days (light-dark 6 : 18), small amounts of melatonin (50 micrograms per day; 100 millimeters capsule length) prevented testicular regression; but testicular atrophy occurred in hamsters that received larger amounts of melatonin (75 to 100 micrograms per day; 150 to 200 millimeters capsule length) and in control hamsters that received none. The results demonstrate that melatonin can exert either pro- or antigonadal effects and emphasize that the effects of melatonin on the testis cannot be properly assessed unless account is taken of the dosage and mode of melatonin administration and the photoperiod on which experimental animals are maintained.


Human interferon production: superinduction by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole.

Polyinosinic.polycytidylic acid [poly(I.C)] induced production of interferon by a strain of diploid human fibroblasts (FS-4), measured between 5 and 24 hours from induction, is enhanced up to 128-fold by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB), a reversible inhibitor of nuclear heterogeneous RNA synthesis. A normalized dose-effect plot shows a close correlation between the superinducing effect of DRB and inhibition of RNA synthesis. Cultures that contained DRB continue to produce interferon for up to 4 days. Removal of the drug at any time during this period leads to a prompt shutoff of interferon production.


Hemopoietic stem cells in human peripheral blood.

A population of lymphocytes, separable from the great majority by virtue of their larger size and their failure to exhibit the rosetting characteristics of thymus-dependent lymphocytes and bursa-equivalent cells, possess true pluripotentiality. On culture in vivo they proliferate and differentiate into erythrocytic, granulocytic, and megakaryocytic progeny. This may be the first clear demonstration of the primitive progenitor blood cell in man.


Right hemisphere lateralization for emotion in the human brain: interactions with cognition.

Right-handed subjects tend to look to the left when answering affective questions. The relative shift in gaze from right to left is accentuated when the questions also involve spatial manipulation and attenuated when the questions require verbal manipulation. The data support the hypothesis that the right hemisphere has a special role in emotion in the intact brain, and that predictable patterning of hemispheric activity can occur when specific combinations of cognitive and affective processes interact.


Antibody formation in first and second generation offspring of nutritionally deprived rats.

Prolonged partial restriction of calorie intake in young rats results in reduced growth, involution of lymphoid organs, and lymphopenia. After immunization with sheep red blood cells, the number of antibody-forming cells in the spleen and serum hemolysin titers are markedly reduced. The effect is more pronounced on the primary response and on immunoglobulin G antibody-forming cells. Significant impairment of antibody formation is detectable in the first (F1) and second (F2) generation offspring of starved Fo mothers.


Response plasticity of lateral geniculate neurons during and after pairing of auditory and visual stimuli.

Neurons of the lateral geniculate nucleus, responsive only to visual stimulation, show response plasticity during and after pairing of auditory and visual stimuli. Modal response histograms reveal a gradual decrement in the number of spikes at interstimulus pairing intervals of 0 and 100 milliseconds but not 500 milliseconds. This plasticity effect, limited to tonic units, may persist for 2 to 3 minutes after termination of click-flash pairing.


Clades versus clones in evolution: why we have sex.

Sexual reproduction predominates among organisms mainly because most evolutionary change is concentrated in speciation events, and asexual species cannot speciate in the normal sense. Asexual clones seldom diversify rapidly enough to overcome normal rates of extinction. In contrast, phylogenetic groups of sexual species (clades) commonly develop broad, heterogeneous adaptive zones rapidly enough to ensure survival.


Direct observation of domains in wet lipid bilayers.

Domain structure and phase separation in hydrated lipid bilayers have been imaged directly by selected reflection dark-field electron microscopy. Domains in multicomponent bilayers are much smaller than those in single component bilayers, in agreement with results obtained by selected area electron diffraction.


Arrhythmically singing crickets: thermoperiodic reentrainment after bilobectomy.

The circadian control of the calling song of crickets is abolished by severance of the optic lobes. The arrhythmic singing activity of operated animals is unaffected by all possible light conditions, yet the singing can be reentained by a daily temperature cycle. The characteristics of this reentrainment indicate the that temperature is acting as an actual Zeitgeber. In light of these results the current hypothesis which ascribes a driving oscillator function to the optic lobes must be reevaluated.


Binaural beats at high frequencies.

Binaural beats have long been believed to be audible only at low frequencies, but an interaction reminiscent of a binaural beat can sometimes be heard when different two-tone complexes of high frequency are presented to the two ears. The primary requirement is that the frequency separation in the complex at one ear be slightly different from that in the other--that is, that there be a small interaural difference in the envelope periodicities. This finding is in accord with other recent demonstrations that the auditory system is not deaf to interaural time differences at high frequencies.


Myasthenia gravis: passive transfer from man to mouse.

Daily injections into mice of an ammonium sulfate-precipitated immunoglobulin fraction of serum from patients with myasthenia gravis were carried out for up to 14 days. The mice showed reduced amplitudes of miniature endplate potentials and reduced numbers of acetylcholine receptors at the neuromuscular junctions. Some mice showed typical decremental responses on repetitive nerve stimulation, with reversal by neostigmine. This represents the first evidence of a circulating factor in the serum of patients with myasthenia gravis which on passive transfer reproduces features of the disease in experimental animals.


Towards curative treatment of advanced Hodgkin's disease.

Advanced Hodgkin's disease was considered incurable until 1966. The development of combined chemotherapy has led to intensIVe treatment and to cures. Results obtained in 104 patients treated according to acute leukaemia group B protocols are discussed. Staging according to the Rye classification was used, as these patients were treated from 1966 to 1971. Methodology and dosage schemes are discussed. Reponse rates reached 88%, with extended survival. The modifications of therapeutic schedules which led to long-term, unmaintained remissions, are explained. The 5-year survival rate of patients with Hodgkin's disease in stages III and iv who responded, was 82,7%. The effect of histological subclassification on the prognosis is considered. The importance of accurate documentation is stressed, and also the use of laparotomy to prove the staging of the disease so as not to deny the patient the benefit of potential cure with chemotherapy.


The use of the SI in reporting results in chemical pathology--our experience.

Since 1 April 1974 some units of the SI have been introduced in the reporting of results from this laboratory. A change from the conventional way of expressing results to the new system requires careful planning and reorganisation. Our laboratory is the first in this country to make the change and our approach and experiences up to the present, are recorded. Special attention was given to reorganisation of the laboratory, to information supplied to the clinical staff, and to the procedure to be adopted on the day of the change. The impact on the clinical staff is assessed and some possible problems are discussed.


The value of the effort electrocardiogram.

The most useful single predictor of future coronary events, but independent of other risk factors, is an effort electrocardiogram indicating ischaemia. The double Master's test as currently used is apt to fail in this respect in 46% of patients with abnormal hearts. The history of stress testing is outlined and it is concluded that treadmill techniques using the S-T segment index represent a much-needed advance on other methods. A small percentage of false positives and false negatives still remains, even with the most sophisticated computer-assisted techniques, and the reasons for this are discussed.


Subcutaneous lumbosacral lipomas.

Twenty-four patients with subcutaneous lumbosacral lipomas are discussed. The neurological involvement of the lower limbs with incontinence is stressed, the high incidence of intrathecal tethering is shown, and early exploration is advocated.


Severe calcification in a horseshoe kidney. A case report.

Marked calcification in a horseshoe kidney of a Black patient in terminal renal failure is described. The role of pyelonephritis in producing the severe calcification in a horseshoe kidney is discussed. One of the complications of a horseshoe kidney is renal stone.


The nitroblue tetrazolium test in Black patients.

An outline of the development of the NBT test is given. The results of studies in a Black population are given and these conform to the pattern published elsewhere, except that a high degree of positivity was found in pulmonary tuberculosis. The value of the test is discussed, and it is concluded that, except in the rare condition of chronic granulomatous disease, the test is of very limited value in the diagnosis of bacterial infection. The test is positive in many situations of stress and may be mediated through a factor in the 'acute phase'.


A year's experience in a clinic for obese diabetics.

The problem of obesity is not well dealt with in the ordinary diabetes clinic. We therefore started a clinic for obese diabetics, the principles of which are mentioned. We reviewed the results of its ifrst year's activity in relation to 80 patients who attended for at least 3 months, and found: (i) a very frequent family history of diabetes in first-degree relatives (59% among Coloured patients); (ii) very commonly, an abnormal ECG, suggestive of ischaemic heart disease (about 60%); (iii) very frequent serum lipid abnormalities, yet no correlation between high lipid levels and an abnormal ECT; (iv) a mean loss of 5,9 kg over 8,6 months for the 80 patients (mean loss of 10,4 kg by the 8 men); (v) patients who had been fat in childhood actually lost more weight than did those who became overweight only in adult life; and (vi) oral hypoglycaemic drugs and even insulin could frequently be discontinued. We believe the clinic is worthwhile.


Somatostatin and serum gastrin in normal subjects and in patients with pernicious anaemia, chronic liver and renal disease.

The effects of somatostatin (growth hormone release inhibiting hormone) on basal gastrin were studied in patients suffering from pernicious anaemia and chronic renal and liver disease, and during sequential arginine/insulin-stimulated gastrin release in normal subjects. When basal gastrin concentrations were normal (10-50 pg/ml) in controls and in patients who were in renal and liver failure, somatostatin had no effect on gastrin levels. Raised basal gastrin levels in pernicious anaemia and in 2 cases of chronic renal disease, were significantly inhibited by somatostatin with a half-life (T 1/2) of 3-4 minutes. Arginine infusion caused an insignificant rise in serum gastrin which was unaffected by somatostatin, whereas insulin hypoglycaemia significantly stimulated gastrin release, which was inhibited by somatostatin.


Unilateral pulmonary oedema after drainage of a spontaneous pneumothorax. Case report and review of the literature.

This is the ninth recorded case of the rare complication of unilateral pulmonary oedema following drainage of a pneumothorax. The complication should be anticipated if the pneumothorax has been present for longer than 3 days, or if coughing and shock develop after insertion of the drain. Radiological confirmation and prompt treatment are necessary. The literature is reviewed.


Problems relating to the discharge of elderly patients from hospital.

A significant number of White patients over the age of 65 years, admitted to the medical wards of Grey's Hospital, cannot be discharged after treatment. This is a serious problem because they occupy beds needed for patients who are acutely ill. The objective of this study was to determine the reasons for this state of affairs.


Prognostic factors in endometrial carcinoma.

An analysis of 78 patients with surgical stage 1 adenocarcinoma of the endometrium reveals that several factors influence the prognosis. Differentiation of the tumour, and the depth of the uterine cavity, play a role, but a depth of 10 cm seems to be of greater assistance in prognostication than one of 8 cm. The menopausal state is very important, since not one patient who was less than 5 years postmenopausal died from carcinoma, and the majority who developed metastases were between 5 and 10 years postmenopausal. Prognosis did seem to be dependent on age, since the group aged between 60 and 70 years had the worst prognosis. Crude survival figures are useless for determining prognostic factors, and an analysis of patients dying from carcinoma must be made. That definite factors besides the method of treatment affect the survival of patients, makes it virtually impossible to make an accurate comparison of survival figures in different series.


Metastatic carcinoid presenting as a spinal tumor.

A case of carcinoid tumor metastatic to the thoracic spine with associated myelopathy is described. Multiple posterior explorations were singularly unsuccessful in locating and indentifying the metastasis, but an anterior transthoracic exposure allowed identification of the tumor, removal of the osteoblastic epidural mass, and fusion of the spine with a rib graft. The patient's myelopathy improved steadily following surgery without evidence of tumor recurrence or regression of neurologic status. The reasons for the relative absence of central nervous system carcinoid metastases are not known.


Continuous measurement of intracranial pressure with SFT: clinical experiences.

In 29 consecutive patients, the epidural intracranial pressure (EDP) was continuously measured with a semiconductor strain film transducer, and with a telemetric monitoring system in two patients. Factors affecting the EDP during pre-, intra- and postoperative periods were analyzed and their significance in clinical practice stressed.


Pulmonary edema and the central nervous system: a clinico-pathological study.

Pulmonary edema is reported in central nervous system disorders, especially trauma. With head injury, a common associated factor is said to be raised intracranial pressure. Among more than 2,100 patients with serious head injuries and 132 serious cervical spinal cord and/or cervical spinal column injuries, only two clear examples of pulmonary edema that might be considered related solely to such injury were found. Another group of patients with non-traumatic central nervous system disorders in whom pulmonary edema developed was also analyzed. In any case, conclusive pathophysiologic explanations for its production are difficult to find. We believe pulmonary edema occurs only rarely in patients with lesions of the central nervous system whether of traumatic or non-traumatic nature and that the mechanism of its production is not clear.


Vertebral arteriography and microsurgery in the management of dumbbell cervical neurinomas.

Preoperative vertebral angiography is advised when the vertebral artery may be compromised by a large cervical neurinoma. The surgical removal of this type of tumor, particularly when its foraminal extension involves the vertebral artery, is facilitated by the use of the operating microscope.


Closed head injury complicated by nonketotic hyperglycemic hyperosmolar coma.

A case of nonketotic hyperglycemic hyperosmolar coma occurring in a patient with closed head injury and basilar skull fracture is reported. The metabolic abnormality masqueraded as a progression of central transtentorial herniation due to cerebral edema. It is suggested that the development of this complication is related to various predisposing factors normally employed in cases of critically ill, neurologically compromised patients. The anatomic lesions found at autopsy were considered inappropriate as a cause of death; the occurrence of central transtentorial herniation three days before death had been reversed. An awareness of this syndrome is emphasized in considering patients receiving steroids, mannitol, tube feedings, Dilantin, and dehydrative measures as part of their care.


Chronic inflammatory lesions of the sphenoid sinus.

A case of chronic inflammation of the sphenoidal sinus is presented. The intermittent and relapsing nature of the condition is emphasized. Its association with hypopituitarism is distinctly uncommon. The surgical management of the case is discussed.


Tuberculous epidural granuloma simulating a herniated lumbar disc.

A case of tuberculous epidural granuloma producing L5 root compression in a 37-year-old Negro male is presented. Excision of the granuloma and the administration of anti-tuberculous therapy was followed by complete recovery. Tuberculous epidural granuloma simulating a radicular syndrome is rarely seen. A search of the literature revealed only five previously reported cases.


A new method for ventriculocentesis.

A new, safe, simple technique for percutaneous ventriculocentesis has been devised and used in 15 consecutive patients with excellent results and no complications. This method allows rapid access to the ventricular system for diagnostic and therapeutic purposes.


The Moyamoya syndrome and the neurosurgeon.

Three cases (two children, one adult) presenting the angiographic features of the Moyamoya syndrome are reported, and the variety of the arterial collateral system is described. If there is a progressive neurological deterioration as a consequence of an inadequate collateral circulation, the creation of a new collateral vascular channel by way of anastomosis between the superficial temporal artery and a branch of the middle cerebral artery is proposed.


Arterial and respiratory influences on intracranial pressure in infancy.

Ventricular and subdural pressures have been monitored in 23 infants. Pressure waves which were influenced by respiratory and cardiac activity were noted. These were rather long lasting and were influenced more by respiration than by cardiac activity, when the intracranial pressure is low. Respiration and arterial pressure have similar effects when the intracranial pressure is normal, but when the intracanial pressure is increased the effects of respiratory activity are diminished.


A giant schwannoma of cauda equina.

A case of giant schwannoma occurring in a woman 23 years of age with deformity of the foot developing at the age of five years is reported. The gross radiological changes of increased interpedicular distance and erosion of the posterior surface of the vertebra suggested the massive size of the tumour (6'' x 21/2'' x 11/2''). Successful surgical excision of such a large size schwannoma has not been reported previously.


Hemifacial spasm: ultrastructural changes in the facial nerve induced by neurovascular compression.

In patients with hemifacial spasm, pathological changes were found in the facial nerve resulting from neurovascular compression-distortion. These changes are simular to those noted in trigeminal neuralgia.


Unilateral acoustic neuroma and cerebellopontine angle lesions in children.

A case of unilateral acoustic neuroma in a girl of ten years without any stigmata or family history of von Recklinghausen's disease is presented. Despite the relatively large size of the tumor, a complete removal was achieved with preservation of function of the facial nerve and a fortuitous preservation of useful hearing. Such tumors are rare in childhood. A brief differential diagnosis of other lesions in the cerebelloponitine angle is mentioned along with a pertinent review of literature.


Electrical stimulation of the brain. III. The neural damage model.

A major concern in the use of neural prostheses is whether electrical stimualtion can cause irreversible damage to neurons. The Neural Damage Model was devised to study the problem and to provide guidlines. The cerebral cortex of cats was stimulated continuously for 36 hours with balanced, biphasic waveforms. The charge per phase, charge density and current density were varied in 16 separate tests. Of these stimulus parameters the charge per phase was more closely correlatable with neuronal damage than charge density and current density. Furthermore, the findings in this study suggest that current flow is more important than electrochemical reactions in causing neural damage. Correlation between blood-brain barrier (BBB) breakdown and neuronal damage was valid only in the group of animals sacrificed immediately following stimulation. The BBB is restored within one month following electrical injury. Convulsive seizures occurred in all but one of the animals during electrical stimulation. A technique for localizing the electrode sites at autopsy and in the microscopic sections is described.


Diagnosis and management of alveolar proteinosis: the rôle of electron microscopy.

The diagnosis and management of three cases of pulmonary alveolar proteinosis are described. The electron microscopic appearances of lung biopsy material, lung washings, and sputum and the value of this method of sputum examination in extremely ill patients are demonstrated. The practical details of controlled volume bronchial lavage are described and the good clinical and physiological response of patients reported. The findings have been compared with those of experimental pulmonary alveolar proteinosis, and the pathogenesis of the condition is discussed.


Use of carboxyhaemoglobin levels to predict the development of diseases associated with cigarette smoking.

Carboxyhaemoglobin (COHb) levels in tobacco smokers vary throughout the day since they are affected by the pattern of tobacco consumption and the rate at which COHb is eliminated. A method is described whereby a single COHb measurement together with a recent smoking history may be used to estimate the average COHb "boost" produced by each cigarette, the total daily carbon monoxide (CO) uptake from smoking, and the mean COHb level throughout the day. These three indices of tobacco smoke absorption were estimated in nine healthy cigarette smokers on different days, each set of three estimations being derived from separate COHb determinations. The indices were reasonably reproducible within the same person, and the differences between people were statistically highly significant (P less than 0-001). For example, the estimates of mean daily COHb level resulting from smoking ranged from 0-7% to 9-3% in smokers who smoked 15 to 40 cigarettes a day. These differences are sufficiently large to distinguish possible differences in the risk of developing diseases such as ischaemic heart disease which may result from the inhalation and absorption of tobacco smoke. The suggested indices also depend less on the time of the blood test and on the daily pattern of smoking than a COHb level alone. The ratio of the COHb boost to the CO yield of a cigarrette may reflect depth of inhalation more accurately than a smoker's self-assessment. Moreover there was little correlation between these two measures of inhalation in the nine subjects studied.


Mediastinoscopy in the surgical management of lung carcinoma.

Up to December 1973, we had performed 100 mediastinoscopies for lung carcinoma. Fifty-two were positive and 48 negative. In 80 cases there was clinical or radiological suspicion of mediastinal invasion. With radiological evidence of mediastinal node involvement exploration was positive in 32 out of 35 cases, when chest radiography findings were equivocal in 19 out of 45, and when radiology of the mediastinum was normal in only one of 20 cases. Mediastinoscopy was more frequently positive when the carcinoma was oat-cell or anaplastic. Of 48 patients with negative biopsies, 41 were explored. In 26 the carcinoma extended beyond the lung. In 1973 we circularized 83 thoracic surgeons concerning (1) the use of mediastinoscopy for patients with lung carcinoma assessed for surgery, (2) the significance of mediastinal node involvement, (3) the results of radiotherapy alone in patients rejected for surgery, and (4) the survival rate in patients with positive mediastinal nodes treated with surgery alone or together with radiotherapy. The replies to the questionnaire are summarized. The authors emphasize the usefulness of mediastinoscopy but state that care must be taken when deciding to withhold operation for a possible cure.


Local ablative procedures designed to destroy squamous-cell carcinoma.

In a series of experiments in dogs, the bronchial mucosa was either excised or destroyed prior to closure of a bronchial stump following a lobectomy or the reanastomosis of a divided bronchus. The experiments were designed to simulate the clinical situation in which focal areas of squamous-cell carcinoma in situ in the bronchial margin would be managed by local ablation of the mucosa rather than by excision of additional bronchus. The experiments demonstrated that the bronchial mucosa is not necessary for bronchial healing. They also demonstrated that functionally and morphologically normal bronchial epithelium regenerates across the denuded bronchus. The source of this regenerated epithelium appears to be the submucosal glands which remain in the bronchial wall after a variety of local ablative procedures. Since our clinical experience has demonstrated that these submucosal glands frequently contain small foci of squamous-cell carcinoma in situ, we have concluded that either excision or thermal destruction of the bronchial mucosa has very limited clinical application and should be considered only in patients who cannot tolerate excision of more than one lobe of the lung.


Tricuspid valve replacement: a five-year appraisal.

Organic disease of the tricuspid valve required surgery in 18% of all patients undergoing valve replacement over a five-year period. Differentiation of organic from functional disease is difficult and may be made only at open-heart surgery. The results of a series of 56 patients who underwent tricuspid valve replacement are presented; of these, 53 had organic disease. Operative mortality at the end of five years had fallen to 7% with significant clinical improvement in 79% of patients, a reduction in cardiothoracic ratio in 81%, and a low incidence of postoperative tricuspid incompetence.


Acetylcholinesterase-positive nerves of the rhesus monkey bronchial tree.

The rhesus monkey lung was stained both by histological methods and histochemically for specific acetylcholinesterase (AChE). AChE-containing nerves in bundles were demonstrated in connective tissue of the hilum and in association with clusters of ganglion cells. These bundles become associated with the bronchial tree as they enter the lung parenchyma, and their numbers of myelinated fibres diminish as they pass scattered ganglion cells along the bronchial system. Extrachondral and subchondral plexuses of nerves were found to be interconnected and to contribute to the perimuscular varicose nerve plexus of the bronchi and bronchioles. These nerve plexuses were found to extend as far as the respiratory bronchioles. In the bronchial submucosa there are AChE-positive nerve plexuses which arise from three sources: (1) the adventitial plexus in bronchioles, or the subchondral plexus in bronchi, (2) the perimuscular nerve plexus, and (3) AChe-containing nerves associated with the bronchial artery. The submucosal plexus appears to innervate the acinar submucosal glands in bronchi as well as continuing as central nerves in the mucosal folds. In the bronchioles the nerves in the mucosal fold are in close relationship with the mucosa.


Epithelial surfaces of the trachea and principal bronchi in the rat.

The epithelial surfaces in the trachea and principal bronchi of healthy rats were examined by scanning electron microscopy. A system of four cell types, ciliated, microvillous, brush, and goblet cells, in this order of frequency, were found and intermediate type cells were not seen. An extensive area of the surface examined was covered by densely ciliated epithelium. The presence of other cell types beneath the cilia was confirmed by transmission electron microscopy. Areas up to 1 mm in diameter and randomly distributed were observed where microvillous cells predominated and only occasional ciliated cells were found. Most ciliated cells in these areas were adjacent to glandular openings or goblet cells. The larger microvilli of the brush cells were arranged in a coronal configuration elucidated by the scanning electron microscope. Preparatory techniques recently introduced for the examination of soft tissue in the scanning electron microscope facilitated the confirmation of cell types present and the microarchitecture of the epithelial surface.


Multiple nodular pulmonary amyloidosis. A case report and comparison with diffuse alveolar-septal pulmonary amyloidosis.

A case of multiple nodular pulmonary amyloidosis in a 54-year-old Caucasian man is presented. Discrete symptomless radiodensities had developed in this patient's lungs within a period of three years, leading to a suspicion of a neoplastic process. The amyloid nature of these nodules was demonstrated by biopsy. In this case, as in others previously reported, there was no evidence of systemic disease, and immunoglobulins were normal. Local factors probably play an important part in the pathogenesis of this disease. This entity is to be distinguished from the diffuse type of pulmonary amyloidosis, which has a far graver prognosis. Diffuse alveolar septal amyloidosis is usually associated with primary systemic amyloidosis or multiple myeloma and leads rapidly to respiratory distress.


Primary diffuse alveolar septal amyloidosis.

The case is reported of a 61-year-old man with primary diffuse alveolar septal pulmonary amyloidosis. Amyloid infiltration of the heart and other organs was also observed. The clinical findings and laboratory investigations reveal features characteristic of defective gas transfer with pulmonary oedema due to left ventricular failure from myocardial involvement.


Farmer's lung in Devon.

Farmer's lung is a cause of disability to agricultural workers in Devon and there is no evidence that the incidence is falling. A survey of known cases was made to assess the degree of disability in relation to the clinical history, the presence of farmer's lung precipitins, tests of lung function, and radiographic changes. Information was obtained about 200 patients diagnosed between 1939 and 1971. A survey of 148 of these patients showed that the disease was most commonly diagnosed  in men aged 40 to 50 years and the most important symptom at diagnosis was dyspnoea related to occupational exposure to hay or grain. The onset was often insidious and only 67 patients (45%) were diagnosed during the first year of the disorder. Disability was severe in about one-third of the cases. The degree of disability did not seem to be related to the serological changes recorded either at diagnosis or at the time of our survey. Disability was commonly associated with restriction and reduced gas transfer factor and with airways obstruction in more severe cases. Many individuals reporting significant disability had only slightly abnormal ventilatory function tests at rest. Radiographic changes were found at survey in about one-third of the subjects reporting disability. Many farmers had not used an efficient mask. Treatment is unsatisfactory but steroid therapy is effective in acute episodes.


Respiratory disease caused by synthetic fibres: a new occupational disease.

Seven patients exposed to the inhalation of synthetic fibres presented with various bronchopulmonary diseases, such as asthma, extrinsic allergic alveolitis, chronic bronchitis with bronchiectasis, spontaneous pneumothorax, and chronic pneumonia. The histological features are described and an attempt has been made to set up immunological techniques for the diagnosis. A series of histochemical techniques, based on textile chemistry, are proposed for the identification of the inclusions found in bronchopulmonary lesions. The results of the experimental production of the disease in guinea-pigs by the inhalation of synthetic fibre dusts are presented. The prognosis of these cases is good in the acute or recently established cases but is poor when widespread and irreversible fibrosis has set in. The authors consider that pulmonary disease due to inhaled particles is probably set off by an individual factor, possibly immunological.


Comparison of peak flow gauge and peak flow meter.

A comparison has been made of the new peak flow gauge and the Wright peak flow meter. Close correlation was found between measurements made with the two instruments both in normal subjects and in patients. The peak flow gauge is as consistent as the peak flow meter but is cheaper and more portable. It should be useful in survey work in general practice and for loan from hospital outpatient departments where serial measurements are used to monitor patients' progress.


Ability of single-breath nitrogen closing volume to detect early airway obstruction.

In order to determine the ability of single-breath nitrogen closing volume (CV) to detect early airway obstruction, the CV was measured in patients with either minimal obstruction of spirometry or with increased residual volume (RV). A total of 39 subjects was included in this study. The mean CV was largest in patients who had reduced maximum mid-expiratory flow rates (MMF). There was no difference in mean CV between smokers and the patients who had large RV but no airway obstruction, although both groups had higher mean CV than ex-smokers. Normal CV was seen in four of 11 patients who had reduced MMF and in four of seven who had large RV but no airway obstruction. All ex-smokers had normal CV while five of 12 smokers had adnormal CV. The results indicate that the closing volume should be used to complement spirometry, rather than to replace it, for screening of early airway obstruction.


Electrical alternans in cardiac tamponade.

Of nine patients with pericardial effusion due to various causes, four developed cardiac tamponade. Electrical alternans was present in all four, being total in three and ventricular in one. The alternans corresponded very well with the clinical diagnosis of cardiac tamponade and the radiological signs of a large pericardial effusion. In two patients alternans was present even with heart rates below 100 per minute. Apart from the exact (1 : 1) type of electrical alternans, three new types are described, a 2 : 1, 3 : 1, and a varying type. It is concluded that (a) electrical alternans associated with pericardial effusion is strongly suggestive of impending or established cardiac tamponade, and (b) electrical alternans is produced when the heart is oscillating within the pericardial sac distended by fluid with a frequency equal to one-half (exact alternans), one-third (2 : 1 alternans), and one-quarter (3 : 1 alternans) of the heart rate. The aetiology and mechanism of electrical alternans are discussed.


Myocardial ultrastructural changes during extracorporeal circulation wtih anoxic cardiac arrest and its prevention by coronary perfusion. Experimental study.

This experimental work has been carried out with the aim of studying the ultrastructural myocardial changes caused by prolonged anoxic cardiac arrest during cardiopulmonary bypass, and their prevention by means of two different techniques of coronary perfusion--systemic-pressure continuous and low-pressure intermittent perfusion. After 30 minutes of cardiac anoxia, the ultrastructural changes of the myocardial cell were reverted to normal by coronary perfusion; when anoxic cardiac arrest was prolonged up to 60 minutes there was severe myocardial damage, with marked mitochondrial changes and dehiscence of intercalated discs, which persisted in spite of restoring coronary flow. These morphological data were in accordance with the fact that no dog which underwent anoxic cardiac arrest for 60 minutes recovered. Both intermittent and continuous coronary perfusion were effective in preventing anoxic damage; cardiac muscle cells were better preserved by low-pressure intermittent perfusion than by systemic-pressure continuous perfusion, which caused intracellular and intramitochondrial oedema.


Silicosis among grindstone cutters in the north of Nigeria.

Many of the grindstones used in Nigerian homes are quarried from sandstone in a small group of villages near Kano in the extreme north of the country. Of an unselected group of 126 stonecutters from two of these villages 49 were found to have radiographic evidence of silicosis, with progressive massive fibrosis in 17. Those with silicosis had worked longer in the quarries than 77 whose radiographs showed no evidence of silicosis. Sixty-three per cent of the silicotics had respiratory symptoms, the commonest being breathlessness on moderate exertion. Cough was the earliest symptom in 42%. Only 35% had abnormal physical signs in the cardiorespiratory system, 18% had clearly reduced ventilatory capacity, and airways obstruction was evident in 16%. The prevalence of silicosis in these open-cast sandstone quarriers is unexpectedly high. This is probably explained by the intensity of exposure and the particular kind of sandstone being worked. Reduction of dust exposure in these quarries raises severe practical problems, but the inhabitants of this drought-ridden area can scarcely be expected to abandon their traditional livelihood.


Postmortem assessment of chronic airways obstruction by tantalum bronchography.

Tantalum bronchography was performed on 22 left lungs obtained at necropsy. Seven were from patients dying in cor pulmonale as a result of chronic airways obstruction and 15 were from unselected necropsies. Of the latter group, nine had no evidence of respiratory disease and six had pathological changes of emphysema and bronchial mucous gland enlargement when the lungs were examined following formalin fixation. A range of changes in the bronchographic appearances from the normal to the groosly abnormal is illustrated. The main changes in severely diseases lungs were: irregularity of the bronchial walls, failure of the walls to taper towards the periphery, areas of narrowing and dilatation, and 'pooling' of tantalum at the ends of airways. A count was made of the numbers of small airway branches in the most distal 4 cm of the lung and also of the number of airways of less than 1 mm in diameter. Patients dying in cor pulmonale had a significantly reduced total number of patent small airways in the area measured and also fewer patent airways of less than 1 mm diameter compared to both the other groups. Histological study of four of the lungs in greater detail revealed that the reduction in small airways filling was the result of a combination of obliteration and obstruction of the lumen by pus. Tantalum bronchography provides a good indication of the state of the bronchial tree at the time of death, and the changes seen are the result of both acute and chronic disease processes.


An analysis of the physiological strain of submaximal exercise in patients with chronic obstructive bronchitis.

An increasing work rate was performed by 40 patients with chronic obstructive bronchitis, split into two groups according to FEV1 (group M, mean FEV1 1-451. and group S, mean FEV1 0-621.), and by 20 normal, non-athletic men of similar age to the patients. Values for cardiac frequency and ventilation were interpolated to standard oxygen uptakes of 0-75, 1-0, and, where possible, 1-5 min-1. The tidal volume at a ventilation of 20 and 30 1 min-1 was also determined. The cardiac frequencies at oxygen uptake of 0-75 and 1-01 min-1 were significantly higher in the patient groups than in the normal men, and were highest in patient group S. The cardiac output when related to the oxygen uptake was in the normal range in all three groups of subjects, so that the patients had smaller stroke volumes than the normal men. Ventilation at oxygen uptakes of 0-75 and 1-01 min-1 was significantly higher in both patient groups than in the normal subjects; there were no significant differences between the two patient groups, Values for dead space/tidal volume ration, alveolar-arterial oxygen gradient, and the percent venous admixture measured during a constant work rate test were significantly greater than normal in the patient groups. Possible factors limiting exercise tolerance in these patients were assessed by extending the increasing work rate test from submaximum to maximum exercise. Changes in blood gas tensions and blood lactate concentrations from resting levels were small, and probably did not limit exercise performance. Measurements at maximum exercise did not add appreciably to the analysis of the disturbed cardiopulmonary function. This study has shown that major disturbances in cardiopulmonary function can be demonstrated without the need for stressing a patient to the limit of his effort tolerance.


Interaction of corticosteroids and catecholamines in the treatment of asthma.

Twelve patients with airways obstruction (due to asthma and/or chronic bronchitis) were given a trial of prednisone therapy to assess reversibility. Six asthmatic patients responded well but no predictive criteria were found. In three patients improvement in forced expiratory volume in 1 second (FEV1) was detectable at 6 hours but not at 3 hours. One patient took 36 hours to show any sign of improvement. None of the patients who improved reached their peak FEV1 before six days treatment with prednisone, which suggests that a 'trial of steroids' should last for at least one week. Potentiation, as measured by either a greater peak rise or a more sustained increase in FEV1 after isoprenaline, was observed in five of the six asthmatic patients responding to steroids. It is concluded that potentiation of catecholmines is one of the mechanisms by which corticosteroids may act in asthma.


Nocturnal and morning asthma. Relationship to plasma corticosteroids and response to cortisol infusion.

Nocturnal and early morning breathlessness is a common and important symptom in asthmatic patients. Six patients in whom these symptoms were a major clinical problem have been studied by serial measurements of peak expiratory flow rate (PEFR) and plasma corticosteroids over two 24-hour periods. Although PEFR and plasma corticosteroids are lowest during the night or early morning, preventing the nocturnal fall in plasma corticosteroids by cortisol infusion did not prevent the fall in PEFR in five out of the six patients. The circadian rhythm of corticosteroid secretion does not appear to be the main cause of nocturnal and early morning asthma.


Effect of fiberoptic bronchoscopy on respiratory performance in patients with chronic airways obstruction.

Lung volumes, airway resistance, expiratory flow rates, distribution of ventilation, and arterial blood gases were measured before and after fiberoptic bronchoscopy in 13 patients with moderately severe chronic airways obstruction and in 10 healthy non-smoking controls. Arterial blood gases were also monitored serially during the procedure. Arterial oxygen tension (Pao2) fell during fiberoptic bronchoscopy in both patients and controls whereas arterial carbon dioxide tension and pH remained unchanged. Control subjects had no change in lung mechanics after fiberoptic bronchoscopy. However, the patients consistently developed increased airway obstruction after fiberoptic bronchoscopy. Within 24 hours after bronchoscopy lung function in the patients returned to baseline values, except for the residual volume which remained abnormally high. The topical application of lignocaine (Lidocaine) for local anesthesia before fiberoptic bronchoscopy produced no effect on lung mechanics in nine patients and 10 controls, but Pao2 decreased in both the patient and control groups. These results indicate that fiberoptic bronchoscopy consistently inpairs lung mechanics and gas exchange in patients with chronic airways obstruction but that the impairment is mild and reversible. Lignocaine administration as well as the intubation procedure contribute to the fall in Pao2 which occurs both in the patients and in subjects without pre-existing lung disease.


Intraoperative autologous blood transfusion: report of a technique.

Using a simple and relatively inexpensive technique, blood was salvaged during major thoracic and cardiovascular surgery in 34 cases. Detailed haematological, biochemical, and bacteriological studies were carried out, with red cell survival studies. It has been shown that cellular as well as non-cellular elements of the blood were well preserved with little or nor bacterial contamination. It has been suggested that this form of autologous blood is a more suitable form of blood replacement than donor blood.


Generalized pulmonary hyperinflation and Fallot's tetralogy in a neonate investigated by pulmonary physiological and radioisotopic methods.

An infant is described who presented a complex cardiopulmonary problem which was evaluated with the help of new physiological techniques. the infant was born at term after an emergency Caesarian section for fetal distress and was found to have meconium aspiration. He remained persistently tachypnoeic and hypoxic despite high ambient oxygen. Chest radiography suggested cystic lesions at the lung bases, and lung function tests confirmed hyperinflation with delayed nitrogen washout. In addition the child had signs of Fallot's tetralogy, and this diagnosis was confirmed by cardiac catheterization. Because of persistent hypoxia and tachypnoea disproportionate to the cardiac condition, the possibility of localized lung disease was considered. Regional lung function tests were carried out in the neonatal period and again at six months of age useing radioisotopic 13N given by both inhalation and injection. These studies showed gross ventilation/perfusion imbalance in the lungs, particularly marked at the bases, but with enough generalized abnormality to preclude the possibility of surgical intervention. The principles of the measurement of lung mechanics in the newborn by whole-body plethysmography, nitrogen washout, and regional radioisotopic spirometry are outlined. The particular value of these techniques in the evaluation of complex disorders is discussed, especially where both cardiac and pulmonary abnormalities are present.


Dissolving foreign bodies in the trachea and bronchus.

Two young children inhaled sweets which dissolved in the tracheobronchial secretions and caused severe respiratory obstruction. The viscid fluid produced as the sweet dissolved was not expectorated and bronchoscopy was necessary. The oedema of the mucosa caused by the presence of a hyperosmolar sugar solution took up to 48 hours to resolve; antibiotics and steroid cover were considered necessary. The similarity of presentation with acute tracheobronchitis and the lack of reports in the literature suggest that such cases may be misdiagnosed.


Carcinoid heart disease: successful tricuspid valve replacement.

A woman aged 46 was found to have severe tricuspid valve disease 14 years after the diagnosis of a malignant carcinoid tumour of the ileum and 33 years after the onset of symptoms attributable to the disease. Increasing ascites requiring repeated paracentesis had not responded to chemotherapy including infusion of 5-fluorouracil and vincristine into the coeliac artery. The tricuspid valve was replaced by a Björk-Shiley prosthesis. After operation there was no recurrence of ascites or oedema. She remains well one year and 11 months later. It is suggested that valve replacement surgery should be considered more often in patients with carcinoid heart disease. Hepatomegaly and ascites sould not be attributed too readily to advancing malignant disease without careful consideration of the role of right-sided valvar lesions in the production of these signs.


Carcinoid tumour of the thymus gland: report of a case.

CARCINOID OF THE THYMUS IS A RARE PROBLEM A case is reported to add to only 16 previously reported. None of these 17 patients had the carcinoid syndrome. Complete surgical excision, if possible, is the treatment of choice.


Adenoid cystic carcinoma of the oesophagus.

A case of adenoid cystic carcinoma of the oesophagus occurring in a patient who had previously been treated for craniopharyngioma is presented. This is the thirteenth reported case of adenoid cystic carcinoma of the oesophagus and the first in association with craniopharyngioma. The previously described cases of oesophageal adenoid cystic carcinoma are critically reviewed, and it is suggested that this tumour is in general highly malignant and may not be so rare as is generally thought.


Supravalvar aortic stenosis syndrome with stenosis of all aortic arch branches.

A 9-year-old girl with the supravalvar aortic stenosis syndrome is presented. In addition to the classical features of the syndrome, namely supravalvar aortic stenosis, peripheral pulmonary stenosis, typical facies, and mental retardation, she was also found to have stenosis at the origin of all aortic arch main branches, a hitherto undescribed feature.


Multifocal haemangiomatous malformation: a case report.

A rare case of haemangiomatous malformation affecting the mediastinum, spleen, kidney, and liver is described. The literature concerning mediastinal haemangiomas is discussed.


[Further studies on the effect of management and milk production on fertility in cattle (author's transl)].

The results of first and second inseminations carried out by the associations of artificial insemination of Sijbekarspel and Stompetoren during the period from November 1971 to November 1972, were studied more closely. The reason for this study consisted in the fact that there were systematic differences in the results of 60-90 days non-return after first inseminations between the two associations. Although the size of the farms (determined by the number of first inseminations) actually had an effect on the results of the inseminations within the herds of the two associations, this cannot account for the difference between the two associations. The effect of the size of the farms, summarized in the concept of management, is also determined by the choice of bulls. The milk-production level did not have any overall direct effect on the results of insemination.


[Studies on the fertility of a number of A.I. bulls in herds of various sizes (author's transl)].

The inseminations carried out with semen collected from eight bulls were counted and arranged according to the size of the herds in which these bulls were used. A study of the figures shows that the conception rate attained by each bull decreases as the size of the herd increases. Evaluation of the fertility of a bull will therefore not only depend on semen quality but also on the management of the farm on which the bull is used.


[Poultry vaccination against N.C.D. by means of an intramuscular injection with LaSota strain vaccine; a practical investigation (author's transl)].

An intramuscular N.D.C. vaccination with LaSota vaccine, in animals of less than ten weeks which were previously vaccinated by the spray method at about 5 days and 25 days against N.C.D., leads to an immunity of at least three months, as expressed by a high concentration of haemagglutination inhibiting antibodies in the circulatory system. If the vaccinated animals are older than twenty weeks, the resulting immunity is very high indeed and shows practically no impairment within a year after vaccination (longer periods have not been investigated), so that it may be assumed that revaccination will not be necessary during the laying period. Antibody variations between different animals of a flock are slight. The residual immunity of previous vaccinations did not appear to affect the development or maintenance of the antibodies. No spread of vaccine was observed. Here it should be noted that animals with a low residual immunity were used for control. It would be desirable to use specifically pathogenfree animals for this purpose, but this is not really practicable in field conditions. Half a hen dose of the LaSota vaccine, dissolved in 1/2 ml physiological saline, was injected into the pectoralis muscle with the help of the Cornwall Pipetting Unit. Twenty flocks, involving 6900 animals, were vaccinated in field conditions. Not a single vaccination gave rise to any vaccination reaction. The method does have a high labour content; which is an objection.


[Results of semen separation using a modified electromagnetochemical method (author's transl)].

The results of a field trial of an electrophoretic method of semen separation (EMC) are reported. The use of this procedure resulted in a slight but statistically significant decrease in conception rates. 10,251 births due to inseminations with separated semen of thirty-seven different bulls were recorded. Changes in the normal sex ratio were not observed.


[Death by malpractice? (Corticosteroid administration to fattening-calves) (author's transl)].

A fatting-calf suffering from an acute bronchi(oli)tis, was treated with antibiotics and dexamethasone. Although the pulmonary complaint healed, the patient died a few days later because of internal haemorrhage from an abomasal ulcer. The article makes a possible connexion between the therapy and the ultimate cause of death plausible.


Induction of abortion in cattle with prostaglandin F2alpha and oestradiol valerate.

Twenty, 2 to 5 months pregnant heifers were injected with 25 mg. and 12.5 mg. Prostaglandin F2alpha on two consecutive days or with a single dose of 20 mg. of a long acting oestrogen (oestradiol valerate). Abortion occurred at an average interval of 3,6 days in the 10 PG F2alpha treated animals and after 10,8 days in 8 out of 10 oestradiol valerate treated heifers. The foetuses of the PG F2alpha treated heifers were in a fresh state while the oestradiol foetuses were already degenerating at the time of abortion. A rather severe vaginal discharge after abortion was more often observed in oestradiol valerate induced abortion. Development of the mammary glands and prolonged oestrus periods also was more pronounced in these animals. In both treatments the concentration of progestins in peripheral blood dropped to less than 1 ng/ml at the time of abortion. The decline was very rapid after administration of PG F2alpha and rather slow after oestradiol valerate. Based on its rapid luteolytic effect and rapid elimination after administration which prevents interferring with the endocrine system for a prolonged time, PG F2alpha is preferred as an abortifacient during the first 4 to 5 months of pregnancy in cattle.


Cold hemagglutinin disease in a toy Pinscher dog.

High titers cold agglutinins were demonstrated in the serum of a 7 year old female toy Pinscher with a hemolytic anemia. In vitro, the serum did not show distinct hemolytic properties, but it fixed complement components to both the patient's own red cells and randomly sampled canine erythrocytes and agglutinated these cells at high dilutions at low temperatures (optimally at 0 degrees C). Serum electrophoresis on cellulose acetate membranes failed to reveal a paraproteinemia. Normal canine red cells sensitized with the patient's serum at 0 degrees C and eluted at 40 degrees C, released a cold agglutinin identifiable as IgM by immunoelectrophoresis. Neither IgA nor IgG were detectable in a concentrate of the eluate. The auto-antibody showed no specificity against the canine blood group A antigen and did not react with human O-erythrocytes, irrespective of whether these carried the I- or i-antigens. Following erroneous exposure of the dog to cold, cyanosis and serious gangrene developed at the acra (the ears, nose and feet). In addition, symptoms indicating diffuse intravascular coagulation were observed both hematologically and on pathological-anatomical examination. No primary disease could be demonstrated.


HL-A antigen, gene, and haplotype frequencies in Denmark.

Between 426 and 1,967 unrelated Danes have been HL-A typed for most presently known HL-A antigens of the LA (first), FOUR (second), and AJ (third) segregant series. Antigen, gene and haplotype frequencies with delta values are given. AJ series antigens are most strongly associated with some of the FOUR series antigens, and except for one case, the linkage disequilibrium between AJ and FOUR does not seem to be influenced by the LA series; the exception concerns HL-A9, RH-315, and 12: the RH-315 determinant is significantly more frequent on HL-A9, 12 haplotypes and on other HL-A12 carrying haplotypes. The term "superhaplotype" is suggested for gene constellations such as the HL-A9, RH-315, 12 "haplotype". It is suggested that the associations between cross-reacting antigens from one series with the same antigen from another series may reflect recent evolutionary divergence of the cross-reacting antigens.


HL-A system in the Japanese population 1.

The antigen W22 was found to be subdivided into three components in the Japanese population. Population and family studies indicate that at least two of these components are new antigens. By using both known and new antigens, gene and haplotype frequencies in the Japanese population are shown.


A freeze-fracture study of the tegumental membrane of Schistosoma mansoni (Platyhelminthes:Trematoda).

Two fracture faces in each half of the freeze-fractured tegumental membrane of adult Schistosoma mansoni indicate the presence of two trilaminate membranes. This result is compatible with the heptalaminate appearance of the tegumental membrane in ultrathin sections. Intramembranous particles are located mainly in the outermost leaflet of the outer membrane and in the cytoplasmic leaflet of the inner membrane. The tegumental membrane of the cercaria (infective larva) has a single fracture plane, which conforms with its trilaminate appearance in sections. Intramembranous particles are extremely numerous and are almost all located in the cytoplasmic leaflet.


Morphological and histochemical evidence of mitoribosomes in Manduca sexta.

The mitochondria found in the neurons of the frontal ganglion of Manduca sexta contained numerous mitoribosomes. The mitochondria of the glial and perineural cells did not contain mitoribosomes. The mitoribosomes were digested in RNase whereas phospholipase C digested the cellular membranes but had no effect on the mitoribosomes.


[The development, structure and function of the mandibular glands of Blaberus craniifer burm. (Dictyoptera Blaberidae)].

The mandibular glands of Blaberus craniifer are examined by histochemical, electrophoretic, thin-layer chromatography and electron microscopical techniques. These glands are known to secrete a volatile aggregative pheromone. The gregarious behaviour increases during insect development and is maximal in imagos. Each gland is composed of a bundle of secretory cells with efferent ductules which arise in a common duct. Secretory cells contain a myeloid secretion more abundant in imagos than in larval stages. Histochemical and electrophoretic criteria show that the myeloid product is made up of a mixture of glycoproteins. A lipidic component is also present in the secretion; its ultrastructural localization remains to be elucidated. Cytological features are in agreement with the gregarious behaviour of cockroaches. Detailed structure and functional interpretation are also discussed.


Ultrastructural changes in an unciliated sensory receptor during activation of the metacestode of Hymenolepis microstoma.

The fine structure of an unciliated sensory receptor of the metacestode of Hymenolepis microstoma is described. Each receptor contains a basal body inserted into an electron dense matrix; a terminal cilium is lacking. At this stage of development neurotubules were lacking, but rapidly appeared following excystation. It is suggested that neurotubules play a role in the functioning of the putative proprioceptor.


Cylindrical organelles associated with microtubules during sperm elongation in a mealybug.

Spermiogenesis in the mealybug Pseudococcus obscurus involves the elongation of a cytoplasmic papilla from the surface of a spermatid. Longitudinally oriented fibers and microtubules, with diameters of 250 A and a non-9+2 arrangement, are associated with this process. Fibers alone are found in early stages of papilla emergence and in the basal region of the elongated papilla. They appear to be continuous with the microtubules in the more distal region of an elongated papilla. Disk-shaped, circular, and rectangular profiles are associated with the basal ends of the fibers. Probably the fibers are microtubular "anlagen" and the associated structures may be microtubular "organizing centers".


Structural and functional dynamics of oogenesis in Glossina austeni: vitellogenesis with special reference to the follicular epithelium.

Morphological changes of the oocyte, follicle cells and nurse cells of the ovaries of the viviparous fly Glossina austeni during vitellogenesis and postvitellogenesis are outlined. During vitellogenesis, material is pinocytosed and incorporated into yolk spheres by subsequent fusions. Various lines of evidence are presented that indicate much of this material is derived from the follicular epithelium. The ultrastructure of the follicular cells throughout the 9 day cycle and their role in protein synthesis is presented. Subsequent to vitellogenesis, the follicle cells synthesize the secondary envelopes.


Intercellular communication in a positional field. Ultrastructural correlates and tracer analysis of communication between insect epidermal cells.

The junctional membrane in the epidermal cells of the larval beetle (Tenebrio molitor L.) is comprised of macular gap junctions embedded in septate junctions. Ultrastructural and morphometric analysis of the distribution of gap junctions within the segmental epidermis suggests that this junction alone could account for the high electrotonic coupling recorded for the epidermal sheet. Analysis of the lanthanum-impregnated septate junction makes it doubtful that this junction serves as a communicating channel between beetle cells. A new model for the septate junction is presented in which pleated septa, less than 30 A thick, connect adjacent plasma membranes; the septa themselves are interconnected by two interseptal platforms that are coplanar with the plasma membranes. Iontophoretic injection of organic tracers into single epidermal cells suggests that only molecules of less than MW 1000 can transfer between cells through low-resistance junctions.


Inverted gap and other cell junctions in cockroach hemocyte capsules: a thin section and freeze-fracture study.

Freeze-fracture and thin-section studies were done on cockroach hemocytes that had encapsulated implanted pieces of Araldite. Desmosome-like junctions and 'B' type gap junction were described. Freeze-fractured gap junctions displayed fused and clustered, but not hexagonally arrayed intramembranous practicles (approximately 130 A) on the B face and pitted areas on the A face of the plasmalemma. Gap junctions were quite numerous and counts of gap and non-gap particles indicated at least a five-fold particle density increase (4000/mu2) compared with B face particle densities (approximately 800/mu2) from free circulating blood cells where gap junctions had not been formed.


Application to a radioimmunoassay for angiotensin I to the measurement of plasma renin in rabbits, and comparison with a biological assay of plasma renin activity.

A radioimmunoassay method for ileu-5-angiotensin I was applied to the measurement of plasma renin in rabbits. In the present method, the volume of plasma sample, required for the determination of plasma renin activity and plasma renin concentration, could be reduced to 0.6 ml and 0.05 ml, respectively. A satisfactory correlation (r = 0.918) was found between the plasma renin activity measured by our bioassay method reported previously and that by the present radioimmunoassay method in each of 25 different plasma samples. A highly significant correlation (r = 0.968) was also observed between the plasma renin activity and the plasma renin concentration, both of which were measured by radioimmunoassays, as far as renin concentration remained under 200 ng/ml/hr. On the other hand, the present results appear to indicate that, when a high plasma renin activity was obtained, it was difficult to evaluate the actual plasma renin concentration. Therefore, it would be necessary to be cautious to apply the method for plasma renin activity on the renin rich plasma.


The effect of pentazocine on PHA-stimulated human lymphocyte transformation.

The effect of pentazocine on lymphocyte transformation induced by PHA was studied in vitro by observing the incorporation of 3H-thymidine into nucleic acid of the lymphocytes. Pentazocine in therapeutic concentrations was shown to inhibit lymphocyte transformation.


On metal elements in pure pigment gallstones.

T total of 17 metal elements (Ag, Al, B, Bi, Ca, Cu, Fe, K, Mg, Mn, Mo, Na, P, Pb, Si, Sn and Zn) were identified by spectroanalysis of various gallstone specimens. In the pure pigment stone which is characterized by black appearance, the metal elements were more various in sort and the spectra of respective elements were more intense than in the calcium bilirubinate stone and the cholesterol stone. As compared with other gallstones, the pure pigment stone contained Ca, Cu, Fe, Mg and Mn at higher concentrations, as determined by semiquantitative analysis, and on incineration yielded more ash. Concentrations of Ca and Mg seemed to parallel the ash content of gallstone, while Cu and Fe did not show such a tendency and were relatively specific to the pure pigment stone irrespective of ash content. These results indicate that metal elements, particularly Cu and Fe, play a role in the formation of black substances of the pure pigment stone, possibly as complex compounds with bilirubin derivatives.


Separation of gastric mucosal cells of rat with proteolytic enzymes, pronase and trypsin, with special reference to the collection, morphology and viability of the generative cells.

Methods to separate and collect gastric mucosal cells of the rat using proteolytic enzymes were devised. Pronase (1.0%) achieved better results than did trypsin (2.0%) in collecting single isolated cells with higher cell yields and viability. The cells dissociated with trypsin retained glandular structures as in situ. The measurement of radioactivity revealed that the incorporation of 3H-thymidine into generative cells was highest in the cell suspension collected by the second 15 min dissociation. It was concluded that the most effective method to obtain dissociated cells from the generative zone of the mucosa is to collect the cells dissociated with 1.0% pronase continuously for a period from 15 to 45 min after the start of dissociation. On autogradiographic analysis with 3H-thymidine, the ratio of generative cells was 10%, approximately 3 X 10(5) cells, in the specimens.


Aging and scar tissue in human heart muscle.

Histometrical estimation of scar tissue was made on 30 human hearts obtained at autopsy in order to know possible correlations between aging and scar tissue in the heart muscle. Estimation was made on histological specimens of the anterior wall of the left ventricle and the posteromedial papillary muscle, according to Chalkley's point counting method, and the amount of scar tissue was expressed in percentage. The mean percentages were 3.11, 5.26 and 9.24 in the epicardial, endocardial parts of the left ventricle and the papillary muscle, respectively. There were very significant differences between these 3 mean percentages. There were very significant correlations between the percentages of scar tissue in these 3 parts and ages. From these results, it is concluded that the scar formation increases in the heart muscle with aging.


Infrared absorption spectroscopy of pure pigment gallstones.

Pure pigment stones, a minor variety of gallstones characterized by black appearance, were analyzed by infrared absorption spectroscopy. The spectra of these stones resembled those of calcium bilirubinate in position of respective absorption bands, but they were smoother in general aspect than spectra of usual calcium bilirubinate stones. From this and other findings the main constitutents of the black stones have been identified as polymers of bilirubin derivatives. It was also revealed spectroscopically that the stones were associated with carbonate and/or phosphate of calcium at an incidence of 65 percent, and that they were less commonly associated with organic bile components such as cholesterol, bile acids and fatty acids than calcium bilirubinate stones. In order to quantitate "smoothness" of the spectrum, the quotient Q was calculated from intensity readings at three determined positions, including 1624 cm-1 at which the absorption is due to pyrrole rings of bilirubin. The "smoothness" was found to correlate well with "blackness" of the stone, Q being less than 0.30 for 91 percent of pure pigment stones and over 0.30 for all specimens of calcium bilirubinate stone and synthetic calcium bilirubinate.


Renal impairment in patients with paroxysmal nocturnal hemoglobinuria.

Three patients with paroxysmal nocturnal hemoglobinuria accompanied by chronic renal lesions were studied. All the cases had histories of severe hemolytic anemia and repeated hemoglobinuria. The biopsy specimen of the kidney of two patients (Case 1 and Case 2) showed interstitial nephritis. Renal glucosuria, tubular proteinuria, increased urate clearance (Case 2) and reduced tubular reabsorption of phosphate (Case 3) were revealed in Case 2 and Case 3, suggesting renal tubular impairment. From the nephrological point of view, hemodynamic alteration resulting from intravascular hemolysis and severe persistent chronic anemia may primarily be responsible for the renal impairment.


Effects of 1-sarcosine-8-isoleucine-angiotensin II on blood pressure and plasma renin activity in various types of hypertension.

The pharmacological effects of 1-Sar-8-Ile-angiotensin II on blood pressure and plasma renin activity (PRA) were studied in 5 normal subjects and in 19 patients with hypertension of various etiologics including malignant hypertension, renovascular hypertension, essential hypertension, and primary aldosteronism. Intravenous administration of this peptide induced a significant pressor response in normal or low PRA subjects at infusion rates of 100-600 ng/kg/min. Similar pressor response was also observed in renovascular hypertensives with normal PRA who were cured later by surgical treatment. The blood pressure in high PRA group was lowered remarkably by infusion of this angiotensin II inhibitor. A significant increase in PRA was obtained in subjects with malignant hypertension following the infusion of this peptide. However, there was no detectable rise in PRA in other subjects with normal or high PRA. The present data show that circulating angiotensin II plays an important role in maintaining high blood pressure in high PRA patients, especially in malignant hypertension, while it is not directly involved in the maintenance of high blood pressure in human chronic renovascular hypertension.


One step separation of the sialoprotein possessing ABH and MN blood group activities from human red cell membrane.

Sialoprotein possessing blood group activity has been usually extracted with organic solvents from red cell membrane. To obtain the blood group substance under milder condition, the author presented carboxymethyl (CM) cellulose column chromatography with eluents of phosphate buffer containing 1% Brij 35. Red cell stroma was applied onto the column with an equal volume of 0.0175 M phosphate buffer pH 6.3 and one-fifth volume of 0.05% 2-mercaptoethanol in 1% Brij 35. Separation of the substance was performed by stepwise elution with three kinds of phosphate buffers. Serological assay showed that only the first fraction eluted with 1% Brij 35 in 0.0175 M phosphate buffer pH 6.3 and ABH and MN blood group activities and the other fractions obtained with buffers of higher molarities had not such activities. Sialic acid was also detected only in the first fraction, and the majority of proteins of the stroma was found in the other fractions.


[Evaluation of various factors influencing the choice of therapy and the prognosis of the uterine corpus carcinoma].

Results are reported from the treatment of a group comprising 246 women with carcinoma of the uterine corpus. Of these, 126 patients were treated surgically and afterwards irradiated, whereas 120 were exposed to radiation methods only. The five-year survival rate without recurrence was 73,8% of the surgically treated cases and 37,7% of the patients who were only irradiated. It has to be noted, however, that the two groups are hardly comparable, since the second group mostly consisted of inoperable cases in advanced stages and in a bad general state. Postoperative radiotherapy proved very useful. The reexamination of this group revealed considerable diminution of recurrences and vaginal metastases. Only in three (2,4%) out of 126 patients irradiated after surgical treatment metastases to the vagina were found later on.


Skin dose with cones and diaphragms in 137Cs teletherapy - a study using lithium borate thermoluminescent dosimeters.

Beam definition in 137Cs teletherapy is done either by use of cones for specified SSDs or by means of adjustable diaphragms. Using lithium borate thermoluminescent dosimeters, the skin dose was studied for conditions of the bare cone without any electron filter, the cone with an affixed perspex cup for cutting off the electrons, the cone with an affixed copper plate filter at its face. It was observed that of the above three arrangements, the case employing the copper filter gave the minimum skin dose. Similar skin dose measurements made for a diaphragm type collimator are discussed in comparison with the values for cones.


[Metabolism of calcium in bones following local  x-irradiation. 14. Effect of castration and estrogens on the general response].

The female sex hormones cause a moderation of the local and general metabolic response to local irradiation of an extremity in female white rats. After castration in adult age, therefore, a more intense reaction is observed with more distinctly marked changes of the 45Ca-incorporation. In male rats, consequently, there is a more vivid course of general response. In these, castration contrarily brings about a moderation of the general response.


Behaviour of intestinal lactase after irradiation.

The behaviour of intestinal lactase has been studied in rats after irradiation. The significant increase of activity is not immediate, but slowly and progressively starting from 4 hrs after irradiation. The modifications of the activity are slow and gradual also during the reduction phase. This disaccharase does not show a return to normal values even after three weeks. We suggest that hypothesis that the increase could be due to a modification of the normal synthesis of enzymes caused by irradiation.


Effects of irradiation on the release and retention of labelled DNA in the small intestine of mice.

Mice were whole-body irradiated with 300, 500 and 800 rd (60Co) one hour or three days after administration of 3H-thymidine. The time courses of the total and specific activity of DNA indicate that three days after exposure with 500 and 800 rd the mitotically active cells were selectively lost from the small intestine. The release of labelled DNA was determined in the fraction of DNA soluble in 0.14 N NaCl. The results suggest that the relatively small fraction of soluble DNA belongs to the mitotically active cells probably having died in the interphase.


[Exploitation possibilities of characteristic autoradiations for dermatological radiotherapy].

Several reasons, especially radioprotection of non-affected strata, seem to make it necessary to look for X-ray qualities which effect - in the diseased dermal layers - a more appropriate dose distribution than it was possible to achieve by the X-ray units used so far. Therefore, the possibilities to utilize characteristic autoradiations are examined, i.e. those possibilities being at disposal in the soft-ray range. Practically, there are the series "K" of copper and molybdenum - maybe also those of silver - coming into the question. Using X-ray tubes with copper and molybdenum anodes, the following items are determined, under D.C. operation, in comparison to the wolfram anode tubes which were usually operated until now: Parts of the characteristic autoradiation in the mixture of rays, half-value thicknesses, relative depth doses, stratified half-value depths, the "rates of tissue homogeneity", and - with regard to special care for deeper strate - the "one-tenth value depths" as well as "depth stress factors". The determinations were effected right in dependence on tube tension and focus - skin - distance. The results of the studies, partly demonstrated by practical examples, show that an X-radiation within the so-called soft-ray range corresponds so much the more to the up-to-date conceptions of radioprotection, as this radiation is accepting the characteristics of the monochromatic autoradiation of the anode material. From the clinical point of view, it remains to be exmained preferably whether there will ever be an indication in the range of dermatological radiotherapy that needs a harder quality of rays than those of the molybdene series K.


[Inactivating and mutagenic effects of long-wave UV-light in bacteria with various mechanism of repair].

UV-radiation of 254 nm wavelength produces in the genetic material (desoxyribonucleic acid, (DNA) of bacteria photochemical alterations (lesions) which can lead to cellular death or mutation induction. The biologically most important class of these lesions is the one of the pyrimidine dimers. Bacteria possess three groups of enzymatic mechanisms which can eliminate such lesions under certain circumstances: elimination in situ; removal from the nucleotide chain (prereplication repair); ignoring the lesion (postreplication repair). The biological effect and the importance of these so-called repair mechanisms is reviewed and the occurrence in other organisms is briefly discussed. On the one hand, organisms are exposed to UV-radiation of 254 nm wavelength only under artificial conditions; on the other hand, long-wave solar UV-radiation (between approximately 300 nm and visible light) which amounts to about three per cent of the total energy output, represents the most powerful radiation to which organisms can be exposed under natural conditions to any larger extent. As outlined in the second part of this review, this radiation also induces lesions which may act as substrate for the above mentioned repair mechanisms. With increasing wavelength, lesions may also occur in cellular components other than DNA. The complexity of biological responses arising thereby is discussed.


[Light-induced cancer].

After exposure of mice and rats to ultraviolet radiation, the yield of cutaneous carcinomas regularly depends on radiation dose and dose distribution. In man, according to comparison of radiation climate with cancer frequency and based on distribution studies of skin exposed to light, the rules are supposed to be of the same kind. Thereby, the latent period is additionally influenced by genetically determined radiosensitivity (melanin content; DNA repair and by the action of syncarcinogenic and concarcinogenic factors. The resulting correlations between UV-light absorption and initiation of cutaneous carcinomas are tight in spinocellular carcinoma, distinct in basaloma, and questionable in melanoma. By converting the estimated UV-radiation doses into "Biological Units", it is possible to determine the risk of cutaneous carcinoma induced by artificial radiation sources as compared with the risk by radiation from sun and sky.


[Effect of radiation changes in the spectrum UV on plant organisms].

The synthesis of UV absorbing pigments (flavonoids), induced by UV (lambdamax less than 300 nm) with linear dose dependency, which we have recently observed in seedlings of the Umbelliferae, is described. This may provide a protective mechanism against an excess of solar UV radiation. The physiological importance of UV for the plant is discussed from the point of view of radiation damage and the plant's resistance to it.


[The use of radiation sources in solariums].

Solaria are increasingly in favour. As radiation sources, the following ones have proved useful: high-pressure mercury-vapour lamps, compound radiation systems consisting of high-pressure mercury-vapour burner, series coiled filament and reflector bulbs made of special glass as well as halogen metal-vapour lamps. The spectral distributions of irradiances of these emitters, the spatial and local distribution of their radiant intensity or irradiance respectively are reported as well as the balance of emitted energy, i.e. the distribution of radiant power over the different wave ranges. Demands of radiation technics are pointed out, which ought to be considered for the construction of solaria.


[Effect of the atmospheric ozone layer on the biologically active ultraviolet radiation on the earth's surface].

Based on measurements of the spectral irradiation intensity of UV-B global radiation by Bener (1960) and on the curve of spectral skin erythema effects newly measured by Urbach and Berger (1972), the biologically active UV-radiation at earth's surface has been calculated as a function of sun's altitude and atmospheric ozone content in so-called "Biological Units": BE = mWh cm-2 times erythema efficacy. On the basis of these data, the total daily, monthly, and yearly amounts of biologically active UV-radiation have been determined for the different geographical latitudes and various ozone contents. Approximately two thirds of BU hit the equatorial zone from 35 degrees south to 35 degrees north. Provided that the stratospheric ozone layer would be reduced by ten per cent from the exhaust gases of supersonic planes flying at high-altitude, an increase of BU would result amounting to 18% at the equator, to 19% in middle latitudes, and to 22% at the poles.


The production and clinical features of a chronic stroke model in experimental primates.

The characteristics of stroke in baboons produced by transcranial occlusion of the middle cerebral artery were studied by clinical examination and serial cinematographic studies, the animals being maintained for three years following the stroke. The characteristic deficit in all animals was an initial, fairly dense faciobrachial weakness with, in a few instances, some accompanying leg weakness for a few days, rapidly improving over the first few months. Some animals retained very evident arm weakness; most animals retained weakness of the face; the majority showed recovery of reaching and placing reactions and some movement in all joints of the upper limb, although fine movements of the fingers remained invariably impaired. Homonymous hemianopia, at least to attention, also appeared to be characteristic, but all of the animals recovered a normal gait and leaping was regained. The close correlation between this and human stroke appears to confirm that middle cerebral artery occlusion in the baboon is a reliable, repeatable and acceptable stroke model.


Local cerebral blood flow and vascular reactivity in a chronic stable stroke in baboons.

Blood flow in the hemispheres of baboons three years after middle cerebral artery occlusion has been assessed by the hydrogen clearance technique. Blood flow in the infarct itself varied from very low (8 ml/100 gm per minute) to very high (89 ml/100 gm per minute) values and, averaging the values for the infarct as a whole, it was impossible to distinguish average flows in the infarct from those of the normal hemisphere. Flow values in surrounding zones of the infarct remained significantly lower than those of comparable normal hemispheres, and, excluding the infarct, the mean average hemispheral blood flow was 35.2 ml/100 gm per minute. This indicates a significant reduction in flow in the cortex, subsequently shown histologically to be normal, compared with normal blood flow values for the baboon hemisphere. Autoregulation was lost in the infarct and impaired in surrounding tissue. CO2 reactivity was grossly reduced in the hemisphere as a whole but was present in all areas, even occasionally in electrode placements within the infarct itself. After perfusion fixation of the head, pathological study of the area of infarction showed a fairly consistent distribution, the infarct itself consisting of many dilated blood vessels of non-capillary nature scattered among fibrous tissue in what was virtually a glial scar.


Amaurosis fugax: a clinical comparison.

Amaurosis fugax (transient monocular blindness) is a symptom of retinal ischemia just as contralateral hemiparesis and sensory loss are symptoms of cerebral ischemia. These symptoms are produced by atherosclerotic stenosis of the carotid vessels at the ipsilateral carotid bifurcation and emboli from these areas causing focal, repetitive, retinal ischemia. A study of 31 endarterectomy patients was undertaken to see if eight patients with amaurosis fugax (25%) could be differentiated from 22 patients with transient cerebral ischemia. The patients with amaurosis fugax were found to be younger. They all had 75% or greater stenosis of the internal carotid artery at the bifurcation on the symptomatic side. They all had unilateral visual symptoms and these symptoms were relieved by surgery. The patients with amaurosis fugax were devoid of cardiac disease, while 45% of the cerebral ischemic patients had documented myocardial disease. Amaurosis fugax (transient monocular blindness) in the setting of clinically significant atheroslerosis of the carotid vessels is an indication for carotid endarterectomy.


Chronically impaired autoregulation of cerebral blood flow in long-term diabetics.

Using the arteriovenous oxygen difference method autoregulation of cerebral blood flow (CBF) was tested in 16 long-term diabetics and eight control patients. Blood pressure was raised by angiotensin infusion and lowered by trimethaphan camsylate infusion, in some cases combined with head-up tilting of the patient. Regression analysis was carried out on the results in order to quantify autoregulatory capacity. In the control patients CBF did not vary with moderate blood pressure variations, indicating normal autoregulation. In four of the 16 diabetic patients CBF showed significant pressure dependency, indicating impaired autoregulation. The cause of impaired autoregulation in some long-term diabetics is believed to be diffuse or multifocal dysfunction of cerebral arterioles due to diabetic vascular disease. Other conditions with impaired autoregulation are discussed and compared with that seen in long-term diabetes.


Regional cerebral blood flow response to hypocapnia in the contralateral hemisphere of patients with acute cerebral infarction.

The rCBF response to hypocapnia induced by active short-term hyperventilation was determined in the contralateral hemispheres of ten patients with acute unilateral cerebral infarction. Overall rCBF reduction occurred in only two patients. Regional or widespread abnormal responses to Paco2 reduction manifested as either no change or a paradoxical increase in the rCBF were observed in eight patients. The hemispheric mean rCBF reduction following hypocapnia was diminished as compared with control subjects. Our findings suggest that an impairment of the chemical control of rCBF may occur in the non-infarcted hemisphere during the early period following the onset of cerebral infarction. The pathophysiological mechanisms which may underlie this abnormal rCBF reactivity to Paco2 reduction are considered.