Occupational status variations in disagreements on the diagnosis of cause of death

Studies of occupational status-related risk factors in specific-cause mortality assume that the proportions of disagreements concerning the diagnoses of the cause of death do not vary between different statuses. This assumption was verified by the addition of data concerning the occupation of the decreased (collected at death registration) to a data set comparing the clinicians' and the pathologists' diagnoses at autopsy of the cause of death. It was found that clinicians and pathologists were least likely to agree on the diagnoses of the cause of death of non-manual workers and were most likely to agree on the diagnosis of the cause of death of skilled manual workers. These occupational status differences in diagnostic disagreements reached levels of statistical significance in the neoplasm chapter of the International Classification of Diseases. Artefactual and clinical reasons for these occupational status differences are discussed.

Effects of intrarenal adenosine on renal function and medullary blood flow in the rat

Adenosine is a potent vasodilator of the systemic circulation. Infusion of adenosine into the aorta causes water and sodium retention and a fall in glomerular filtration rate and renal blood flow. The effect of adenosine on medullary blood flow is unknown. Because systemic vasodilatory effects may confound its renal actions, adenosine was infused into the renal artery of anesthetized Munich-Wistar rats at doses of 2, 6, and 15 micrograms/min. A marked dose-dependent increase in urinary flow and sodium excretion was observed. Inulin and p-aminohippuric acid clearance did not change significantly. Blood flow in vasa recta in the exposed renal papilla, as determined by fluorescence videomicroscopy, increased significantly only with the highest dose of adenosine. In control animals infused with the vehicle only, there was no change in any of the above variables. These results indicate that direct intrarenal infusion of adenosine in the rat increases urinary flow and sodium excretion and at higher doses also increases vasa recta blood flow. The effects on urinary flow and sodium excretion were therefore mediated by a mechanism other than an increase in vasa recta blood flow.

Management of asthma in hospital: a prospective audit

In a prospective study of management of asthma in hospital patients with acute asthma admitted to a single hospital over a calendar year were surveyed. Altogether 157 out of 194 admissions (81%) were studied. The patients (16 of whom had been admitted twice and one three times) were interviewed at home about two weeks after discharge, and their hospital records were reviewed. When interviewed an appreciable proportion of patients said that their asthma had been poorly controlled after their discharge from the hospital: 54 reported regular sleep disturbance due to wheeze, 78 tightness of the chest in the morning, and 77 wheeze after climbing one flight of stairs. Patients had been described on admission as having had symptoms of deteriorating asthma for a median of three days. Closer questioning of 71 patients, however, elicited that 50 had had regular symptoms indicating poor control for weeks or months. Most patients did not know how their drugs worked, and many did not have an appropriate plan of action in the event of a further attack. In all the cases studied 114 patients were treated with oral corticosteroids, only 70 had had their previous maintenance treatment increased at the time of discharge, and 107 had a follow up appointment booked for an average of three and a half weeks after discharge. These findings show that undersupervision and undertreatment of patients with asthma are common and not confined to those dying of the condition.

A possible artefactual component in specific cause mortality gradients. Social class variations in the clinical accuracy of death certificates

This paper investigates one possible avenue of artefactual influence on the production and/or concealment of social class gradients in specific cause mortality rates, namely, the possibility of social class biases in the accuracy of diagnosis of cause of death and the systematic misallocation of certain social groups to particular diagnoses. Information on this topic was obtained by matching occupational data gathered at death registration with data on the accuracy of diagnosis of cause of death (measured by diagnostic agreement between clinician and pathologist) collected in a prospective study of 1152 hospital necropsies. Extrapolation from these data to national mortality rates should be cautious, but it appears that in the majority of the most common causes of death grouped by ICD chapter (neoplasms, cerebrovascular and digestive) social class gradients would be steeper if mortality data were based on pathologists' rather than clinicians' diagnoses. Only in the respiratory chapter would the gradient be reduced, with the gradient in cardiovascular deaths unaffected.

Differences in hospital asthma management

Asthma management was audited prospectively for one year in a large teaching hospital. Full details were available on 77% of all patients admitted, or readmitted, with asthma during that year (150 of 195 admissions). 64 patients were admitted to general wards with a special interest in respiratory medicine, and 86 to general wards without this specialist interest. Cases in the two groups were similar in terms of age, previous severity of asthma, previous treatment, and initial pulse rate. Fewer cases in the non-specialist group were treated with oral corticosteroids (67%, vs 83%), had regular peak flow recordings (42%, vs 73%), or were given return appointments (56%, vs 92%); and fewer had their regular inhaled therapy increased after discharge (28%, vs 55%). At interview 13 days later, more patients from the non-specialist group reported sleep disturbance (41%, vs 23%), morning chest tightness (55%, vs 37%), ow wheeze on 1 flight of stairs (58%, vs 34%). 20% of first admissions in the non-specialist group were readmitted within the year, compared to 2% of the group treated on wards with a specialist interest in respiratory medicine. These data suggest that the intensive management of asthmatic patients, practised in respiratory units, prevents much unnecessary morbidity.

Breast cancer and colon cancer incidence in females in Scotland, 1960-84

In view of the suggested similarity in risk factors for breast cancer and colon cancer in women, an analysis was undertaken to investigate age, period, and cohort influences on the risk of these diseases by use of incidence data for Scotland. Statistical modeling of data for the period 1960-84 revealed that both the age effects and the cohort effects were different for each site. While younger cohorts apparently had signs of reduced risk of both diseases, reduced risk was only apparent among the very youngest cohorts in the case of breast cancer, whereas there has been a gradual reduction in the risk of colon cancer among successive cohorts born since the beginning of the century. Clemmesen's hook was demonstrated in the age-incidence curve of breast cancer, which was clearly shown to have two different slopes: among premenopausal and among postmenopausal women. The declining risk of breast cancer in younger cohorts appeared contradictory to their apparently "high-risk" profile (in terms of present knowledge of etiologic factors) and suggested the possible existence of a factor that protects against breast cancer, at least at younger ages, but that remains, as yet, unidentified.

Pre-treatment with beta blockers and the frequency of hypokalaemia in patients with acute chest pain

Plasma potassium concentration was measured at admission in 1234 patients who presented with acute chest pain. One hundred and ninety five patients were on beta blockers before admission. The potassium concentrations of patients admitted early (within four hours of onset of symptoms) were compared with those admitted later (4-18 hours after onset of symptoms). There was a transient fall in plasma potassium concentrations in patients not pre-treated with beta blockers. This was not seen in patients who had been on beta blockers before admission. Non-selective beta blockers were more effective than cardioselective agents in maintaining concentrations of plasma potassium. These findings suggest a mechanism for the beneficial effects of beta blockers on morbidity and mortality in acute myocardial infarction.

Carcinoma of the larynx

Six hundred sixty-eight patients with tumours of the larynx were treated by radiotherapy. The patients had stage T1 N0 M0 to T4 N3 M0 disease. Patients with T1 N0 M0 disease (273) had an excellent long-term survival (90%) as did those with T2 N0 M0 disease (142), whose 5-year survival was 70%. Patients with more advanced disease but no nodal spread did not respond as readily to radiotherapy; the 5-year survival was 40%. All patients were treated using a parallel pair set-up 6 X 6 cm lateral neck fields. A more aggressive radiotherapy regime to a larger tissue volume to include microscopic spread to lymph nodes may improve survival of locally advanced disease.

Saksenaea vasiformis osteomyelitis

A 24-year-old man sustained a crush injury to the tibia, which subsequently became infected with Saksenaea vasiformis. He was treated with debridement and a free myocutaneous flap, but amputation was necessary because of mycotic osteomyelitis. S. vasiformis was recovered and identified on the basis of its characteristic morphology on cornmeal agar.

Statistical modelling of lung cancer and laryngeal cancer incidence in Scotland, 1960-1979

The ratio of cancer occurrence among smokers compared to nonsmokers has been generally reported to be greatest for carcinomas arising in the lung and larynx. This report presents the results of an investigation into mechanisms underlying the temporal trends in the incidence of these two forms of cancer in Scotland over the 20-year period, 1960-1979. The purpose of the study was to establish the independent effects of age, calendar time, and birth cohort on the observed pattern of incidence by adopting an alternative approach to this classical problem which can be employed when data are available as individual records. The most economic model found to explain the data involved the independent effects of site, sex, and age and different cohort effects in each sex. The cohort effect was more pronounced in men than women in older cohorts but, conversely, stronger in women than in men in younger cohorts, i.e., among those born most recently. This observation accords with the observed increase in the use of cigarettes in young women relative to young men. There appeared to be a small effect of calendar time which was the same in both sexes and both sites, although this main effect, it must be emphasized, could be eliminated from the model on statistical grounds. The effect can be interpreted to indicate the increase in the coverage of cancer registration in Scotland which has taken place since 1960. These results indicate that lung cancer risk in Scottish males will continue to fall, with the risk in women lagging 20 years behind, although the levels in women will probably not reach those attained by men.

Relationship between transcutaneous oxygen tension, ankle blood pressure, and clinical outcome of vascular surgery in diabetic and nondiabetic patients

We measured ankle systolic blood pressure (ABP) and limb transcutaneous oxygen tension (TcPO2) before and after 53 vascular procedures performed to relieve limb-threatening ischemia. We compared changes in ABP and TcPO2 and also compared these measurements of limb hemodynamics with the clinical outcome of the vascular procedures. For the procedures performed on patients without diabetes, both ABP and TcPO2 registered similar changes after surgery. Furthermore, those nondiabetic patients who had a postoperative ABP greater than 75 mm Hg or TcPO2 greater than 20 mm Hg showed resolution of the clinical symptoms within 60 days after surgery. All patients falling below these levels underwent a subsequent limb amputation. The results differed somewhat for procedures performed on patients with diabetes. First, a number of diabetic patients showed high ABP in conjunction with low TcPO2. We attribute these observations to the high incidence in diabetic patients of calcific medial stenosis leading to artificially elevated ABP measurements. Second, the clinical outcome among diabetic patients was uncorrelated with the postoperative ABP and was poorly correlated with postoperative TcPO2. Those diabetic patients with postoperative TcPO2 below 20 mm Hg showed unfavorable clinical outcomes, but many patients with postoperative TcPO2 greater than 20 mm Hg and postoperative ABP greater than 75 mm Hg also showed unfavorable clinical outcome (slow healing of ulcers, persistence of rest pain, and/or an amputation on the limb). These data suggest that among our patients with diabetes, simple relief of limb ischemia was not sufficient to result in a trouble-free clinical course. We conclude that TcPO2 is a useful replacement or adjunct to ABP measurements for evaluating the hemodynamic outcome of vascular surgery. Our results also suggest that it is extremely important to evaluate the outcome of such surgeries separately in patients with and without diabetes.

Age, period and cohort models: the use of individual records

Problems with the interpretation of age-period-cohort models are discussed. If individual records are available for cancer incidence in Scotland, then a solution is obtainable. An example using incidence data for cancers of the lung and larynx in Scotland is presented to illustrate the models.

Evaluation of serum theophylline concentrations following administration of sustained-release beads in applesauce to asthmatic preschool children

A sustained-release theophylline preparation (Theo-Dur Sprinkle) was evaluated in young asthmatic patients aged 1 to 6 years and receiving a daily dose of 23.4 +/- 2.0 mg/kg (mean +/- SD) to determine, on the basis of serial serum concentrations obtained over a 12-hour dosing interval at steady state, the suitability of such a product in patients likely to metabolize the drug very rapidly. Peak theophylline concentrations of 15.1 +/- 4.1 mg/L were achieved 5.5 +/- 1.5 hours after dosing. The mean maximum to minimum concentration difference was 6.9 +/- 2.2 mg/L for the dosing interval studied. Fluctuations in theophylline concentration less than 100% were achieved in nine of the 12 study patients. Use of the "sprinkle-technique" with Theo-Dur Sprinkle appears to be a simple and effective method of maintaining acceptable fluctuations in serum theophylline concentrations in preschool asthmatic children.

Snoring in children: is it pathological?

Some children who snore heavily, have been shown to have periods of apnoea which, if frequent, are known as the obstructive sleep apnoea syndrome (OSA). Twenty patients with OSA, who presented to the Department of Thoracic Medicine, Royal Children's Hospital, Melbourne, over a three-year period, were reviewed. The findings indicated that OSA is more common than is generally supposed and that it can present with a wide range of symptoms. It is important that an early diagnosis of this syndrome is made, to prevent major complications and to allow appropriate therapy.

Gastric perforation after acute aspirin overdose

A case is presented of gastric perforation complicating acute aspirin overdose in a patient without previous evidence of peptic ulcer disease.

Term infants with hypoxic-ischemic encephalopathy: outcome at 3.5 years

A total of 167 term neonates with a diagnosis of hypoxic-ischemic encephalopathy (HIE) had detailed neurodevelopmental follow-up at 3.5 years of age. All 66 children with mild HIE were free from handicap; all seven with severe HIE were severely handicapped; and of the 94 with moderate HIE at birth, 21.3 per cent were handicapped. Mean IQ was significantly related to the category of HIE. Within the moderate HIE category, the neurological examination at discharge from the Neonatal Intensive Care Unit was more useful than the presence of neonatal convulsions in identifying children with subsequent developmental delay. Abnormalities on this examination related significantly to an increased number of handicapped children, decreased motor and language skills, and lower IQs. Although neonatal convulsions were associated with an increased number of handicapped children, they did not significantly affect most other developmental outcome measures. In term infants with documented HIE at birth, major neurodevelopmental dysfunction at 3.5 years depended more on prospectively established category of HIE than on other perinatal or social factors.

The effect of Parkinson's disease on the ability to maintain a mental set

In two experiments with an Odd-Man-Out choice discrimination task, Parkinsonian subjects had difficulty in alternating between two rules on successive trials. The pattern of errors suggested that the difficulty arises from an instability of cognitive set rather than any loss of reasoning ability, perseveration or increased distractibility.

Examination of transepithelial exchange of water and solute in the rat renal pelvis

Severance of the ureter beyond the renal papilla causes a fall in urinary osmolality, which suggests that exchange of water or solute between urine and renal parenchyma normally occurs in the intact renal pelvis. We examined water and solute flux in the renal pelvis with micropuncture and microcatheterization techniques. Four groups of antidiuretic rats were studied. Group I (n = 17) underwent micropuncture through the intact contracting ureter. Urine samples were obtained at the papillary tip, and in the pelvis beside the base of the extrarenal papilla. Urinary osmolality at the base, 880 +/- 97 mosmol/kg H2O (mean +/- SE), was less than that at the tip, 1,425 +/- 104 mosmol/kg H2O (P less than 0.005). In group II (n = 24), samples were analyzed for inulin and osmolality. In 15 rats (group IIA), comparison was made between base and tip samples. In the other nine animals (group IIB), comparisons were made among base, tip, and bladder samples and urea was also measured. In group II (A and B combined) urine-to-plasma (U/P) osmolality was lower at the base, 4.31 +/- 0.27, than at the tip, 6.08 +/- 0.23 (P less than 0.001), and U/P inulin was lower at the base, 192 +/- 25, than at the tip, 306 +/- 16 (P less than 0.001). In group IIB, the bladder urine had a lower U/P osmolality, 5.27 +/- 0.25, than the tip, 6.01 +/- 0.31 (P less than 0.02). The U/P urea was 59 +/- 10.6 (base), 98 +/- 9.4 (tip) (base vs. tip, P less than 0.05), and 81 +/- 6.5 (bladder, P less than 0.005, compared with tip). In group III (n = 8), samples were obtained by microcatheter from the fornices, the deepest intrarenal extensions of the pelvis, and compared with samples at the tip. Urinary osmolality was lower in the fornix, 646 +/- 106 mosmol/kg H2O, than at the tip, 1,296 +/- 99 mosmol/kg H2O (P less than 0.001). Similarly, U/P inulin was lower in the fornix, 48 +/- 14, than at the tip, 128 +/- 12 (P less than 0.001). The lower U/P inulin in the pelvic urine is the result of either the addition of fluid to the pelvis, or the backleak of inulin across the epithelium lining the pelvis. To verify that the pelvic epithelium was impermeable to inulin, in group IVA (n = 4) the left renal pelvis was superfused with a solution of chemical inulin. Cumulative absorption of inulin from the left kidney was 0.15 +/- 0.08% of that superfused. Using [14C]inulin in group IVB (n= 3), similar results were obtained (0.05 +/- 0.02%). These findings indicate that in the renal pelvis, fluid is added to urine after it emerges from the collecting ducts. We suggest that reflux of hyperosmotic urine over the renal papilla creates a transepithelial gradient for the flux of water into the pelvis. A model that incorporates diffusive and convective forces for water and solute transport is proposed to account for these findings.

Electron-microscopic study of the apical region of the toad bladder epithelial cell

Antidiuretic hormone (ADH) promotes fusion of cytoplasmic tubules with the luminal membrane and delivery of particles from the tubules to the membrane. The particles are believed to be the water-conducting elements in the membrane. We have employed several scanning (SEM) and transmission electron-microscopic (TEM) techniques to study the relationship of the cytoplasmic tubules to the luminal membrane and to the apical cytoskeleton of the toad bladder epithelial cell. This paper reports the results of freeze-crack SEM and tannic acid-fixed TEM studies, as well as studies with a resinless method of embedding. Freeze-cracked epithelial cells reveal that the tubules are anchored in a matrix of cytoskeleton and granules just below the luminal membrane, and many, if not all, retain their anchorage to the matrix after ADH-induced fusion. Tannic acid-fixed specimens show that the tubules in unstimulated cells lie horizontally. Fusion appears to involve an angulation of the tubules, and this may be the major mode of ADH-induced tubule movement. There are suggestions in the tannic acid sections of filamentous attachments of tubules to the surrounding cytoskeleton. In addition there are prominent microfilament bundles running down the microvilli and a dense concentration of filaments just below the luminal membrane. The presence of these filaments is confirmed in the resinless sections, and their possible role in ADH action is discussed.

Collagen implant: an early assessment

Injectable collagen has been used successfully to improve skin contour defects. This paper will briefly review the biosynthesis, the preparation, and the clinical application of this new material. Collagen is the major structural protein of the extracellular matrix and provides a scaffolding for the support cells. Skin collagen is composed of short fibriles grouped in bundles which are randomly orientated to provide strength and resiliency in all directions of the skin place.

Neurological outcome correlated with spinal evoked potentials in a spinal cord ischemia model

Occlusion of the abdominal aorta of the rabbit by inflating the balloon of a Swan-Ganz catheter positioned in the aorta is a simple and reliable method of producing spinal cord ischemia. The electrophysiological, neurological, and neuropathological correlates of ischemia with progressively longer durations and of ischemia after drug interventions were studied with the goal of developing an easily monitored, reproducible model for central nervous system ischemia. The percentage of animals developing paraplegia after varying periods of ischemia was zero after 15 minutes, 30% after 17 minutes, 33% after 20 minutes, 38% after 25 minutes, and 100% after 60 minutes of ischemia. After 25 minutes of ischemia the percentage of animals developing paraplegia was 87% when they were awake and not ventilated during ischemia and reperfusion, but dropped to 38% in animals that were paralyzed, sedated with ketamine, and ventilated, and when the metabolic acidosis that follows aortic occlusion was corrected during reperfusion. Pretreatment with thiopental, hypothermia, naloxone, methylprednisolone, and verapamil changed the percentage of animals developing paraplegia after 25 minutes of ischemia to 0%, 0%, 25%, 40%, and 100%, respectively. The component waves of the spinal somatosensory evoked potential (SSEP) disappeared sequentially during ischemia in the following order: P2, N4, N3, N2, and N1. After reperfusion, the SSEP components returned in reverse order of their disappearance. In the untreated animals, absence of the N3 wave for more than 10 minutes during ischemia was always followed by a neurological deficit. Pretreatment with thiopental or hypothermia permitted longer periods of electrophysiological silence without permanent neurological deficit. The ratio of the amplitude of N3 to N1 (N3/N1) was at least 70% of the control level, and N4 and P2 amplitudes were at least 30% of the control level at 120 minutes after reperfusion in all animals that had a normal outcome. Return of the N3/N1 amplitude to at least 90% of the control level or return of N3/N1 to 70% to 89% of control and P2 to at least 60% of control at 120 minutes after reperfusion reliably correlated with a normal 48-hour motor examination in animals with and without drug interventions.

Attachment and extracellular matrix differences between tendon and synovial fibroblastic cells

Fibroblasts of the synovium of sheathed tendons were isolated, and their biochemical properties were compared with those of the fibroblasts of the remaining tendon. The synovial cells had a lower attachment efficiency than did the tendon cells. On the day of cell isolation the synovial cells synthesized collagen as 10% of their total protein, whereas the tendon cells synthesized 30% collagen. After growth in fetal bovine serum (FBS), the percentage of collagen synthesized by both populations decreased; however, the synovial cells still made less collagen than did the tendon cells (5 versus 11%). On the basis of cyanogen bromide peptide analysis, the synovial cells were found to synthesize Types I and III collagen in primary culture, whereas the tendon cells synthesized only Type I. The synovial cells also synthesized two to three times less sulfated glycosaminoglycans in culture than did the tendon cells. Thus, the two cell populations differed in attachment efficiency and in their biosynthesis of collagen and sulfated glycosaminoglycans. These differences reflect extracellular matrix differences that have been observed in the tendon in vivo. In addition, the results augment existing data showing that not all fibroblasts have identical phenotypes.