Post-surgical tympanostomy tube follow up with audiology: experience at the Freeman Hospital.

BACKGROUND: Tympanostomy tube (grommet) insertion is a common procedure, with little guidance in the current literature regarding post-operative surveillance. Our institution implemented a protocol to follow up post-surgical grommet patients via audiology at six weeks. METHODS: A retrospective audit of all patients less than 16 years old who had undergone grommet insertion during a three-month period. RESULTS: A total of 149 patients had grommets inserted. Exclusion criteria left a cohort of 123 individuals; 82 (67 per cent) were followed up by audiology. Of these, 13 (11 per cent) did not attend follow up, and were discharged; 53 (43 per cent) were discharged from audiology with normal thresholds; and 16 (13 per cent) were referred back to a consultant. Therefore, the overall reduction in patients followed up by an otolaryngologist was 54 per cent. CONCLUSION: We recommend a six-week follow up with audiology following grommet insertion, allowing for referral back to ENT services in the event of related complications.

Pre-employment health assessments for food handlers: a survey of occupational physicians in the food industry.

The format of pre-employment health screens within the food industry varies considerably. The aim of this study was to produce a consensus on the content of a screen that will enable employees to handle food with minimum risk to the product and employee. A questionnaire was sent to the 63 members of the Food Industry Medical Association, of whom 45 (71%) responded. As a minimum, a questionnaire completed by the applicant is thought to be sufficient. Applicants reporting health problems need to be assessed by a health professional.

The development of circadian rhythms in a human infant.

STUDY OBJECTIVES: This study examines the ontogeny and interaction of circadian rhythms of sleep, wake, temperature, melatonin, and feeding in the human newborn, and the influence of photic and non-photic factors on the initiation of entrainment. DESIGN: An infant's sleep-wake state, temperature, and salivary melatonin were monitored from birth to 6 months. Temperature was obtained every hour, and the infant's sleep/eating onset/termination were observed continuously and recorded until day 182. Salivary melatonin was obtained weekly for a 24-hour period, starting at week 3. SETTING: The infant slept in his parents' bedroom. All household members awakened, retired, and ate meals according to a fixed schedule during the study, while the infant ate, slept, and woke on demand. PARTICIPANTS: A healthy male infant was the subject. Biological parents gathered data continuously for six months. INTERVENTIONS: The infant's schedule was on-demand; the household's was fixed. Illumination was restricted to sunlight. MEASUREMENTS AND RESULTS: The circadian rhythm of temperature appeared first, soon after birth, and became statistically significant within one week. The wake circadian rhythm appeared second, attaining significance at day 45; approximately the same time that increased melatonin concentration began to occur at sunset. The sleep circadian rhythm appeared last, attaining significance after day 56. Ninety to 120 minute zones of sustained wakefulness first appeared in the second month of life subsequent to awakening and prior to sleep onset. The infant's nocturnal sleep-onset was coupled to sunset before day 60 and subsequently to family bedtime, giving evidence of initial photic entrainment followed by social entrainment. CONCLUSIONS: Circadian rhythms appeared much more rapidly in this infant than previously reported; their rapid appearance was probably facilitated by maximal exposure to sunlight, and regular social cues. These lighting conditions replicate universal infant experience prior to the invention of artificial light.

Endothelial function and adrenergic reactivity in human type-II diabetic resistance arteries.

PURPOSE: This study was performed to examine the role of the vascular endothelium in modulating arterial reactivity to adrenergic vasoconstriction in subcutaneous arteries from patients with type II diabetes. METHODS: Small subcutaneous arteries (inner diameter = 90 to 180 microns) from control subjects (n = 22) and patients with diabetes (n = 18) were dissected from skin biopsies obtained at surgery and mounted on a specialized arteriograph that allowed for continuous measurement of lumen diameter under controlled pressure. The sensitivity to norepinephrine was compared in arteries that were either intact, denuded of endothelium, or intact and exposed to N omega-nitro-L-arginine (L-NNA), an inhibitor of nitric oxide synthesis. Stimulated release of nitric oxide by acetylcholine and smooth muscle cell responses to sodium nitroprusside were also evaluated in diabetic and control arteries. RESULTS: Sensitivity to norepinephrine was augmented in diabetic arteries and the amount of agonist necessary to contract the vessels 50% of maximum (EC50) decreased from 0.35 +/- 0.05 mumol/L in the control arteries to 0.16 +/- 0.06 mumol/L in the diabetic arteries (p < 0.05). Both endothelial removal and blockade of nitric oxide synthesis increased sensitivity to norepinephrine in control arteries (EC50 denuded = 0.14 +/- 0.03 mumol/L and EC50 L-NNA = 0.14 +/- 0.04 mumol/L; p < 0.01) but failed to augment sensitivity in diabetic arteries (EC50 denuded = 0.17 +/- 0.05 mumol/L and EC50 L-NNA = 0.15 +/- 0.04 mumol/L; p > 0.05). Stimulated release of nitric oxide by acetylcholine was increased in the diabetic arteries: EC50 control = 0.04 +/- 0.01 mumol/L versus EC50 diabetic = 0.009 +/- 0.001 mumol/L (p < 0.05). Sensitivity of vascular smooth muscle to sodium nitroprusside was similar in both nondiabetic and diabetic arteries. CONCLUSIONS: The endothelium mitigates adrenergic reactivity in control arteries, which is lacking in diabetic arteries and results in enhanced reactivity to norepinephrine; increased sensitivity of diabetic arteries to acetylcholine, however, indicates a possible alteration at the receptor level.

Dithiothreitol treatment permits measurement of melatonin in otherwise unusable saliva samples.

Melatonin research has primarily utilized blood as the source of samples, but there is now increasing interest in measuring levels of the hormone found in saliva. One impediment to this approach is that several melatonin assays involve a column-extraction step that can prove very time-consuming or even impossible when salivary samples are excessively viscous. We have treated 67 samples with dithiothreitol to enhance their passage through the column. Following this treatment, all samples passed freely through the columns. The minimum and maximum values measured were 0.7 - 50.0 pg/ml for the untreated controls and 1.0 - 51.9 pg/ml for the treated samples. The means (+/-SEM) for these groups were 9.5 +/- 1.6 and 9.9 +/- 1.7, respectively, and were not significantly different from one another as assessed by Student's t-test (P = 0.08). In summary, we have found that this technique permits us to obtain values on samples which would otherwise be unusable and that such treatment does not alter the melatonin values yielded by RIA analysis.

Oilseed rape and bronchial reactivity.

OBJECTIVES: To investigate atopy and changes in symptoms, peak flow rate, and bronchial reactivity in people complaining of symptoms during the oilseed rape flowering season. METHODS: 37 people who had given positive answers to questions about the presence of symptoms in relation to the flowering season of oilseed rape and 24 controls with no such symptoms were studied, although not all took part in all parts of the study. All had been previously identified in a cross sectional survey of a random sample of a rural population. Atopy was assessed by means of skin prick tests, total immunoglobulin E (IgE), and radioallergosorbent test (RAST) assays. Bronchial reactivity (PC20) was measured by histamine challenge. Total IgE and bronchial reactivity were measured both before and during the oilseed rape flowering season. Day to day changes were monitored by subjects who kept a record of their symptoms and peak flow morning and evening, starting before the flowering season and continuing during it and into the grass pollen season. RESULTS: Only two cases, of 23 tested, showed evidence of allergy to oilseed rape and only 10 of 23 tested, including these two, were atopic. Eye, nasal, and headache symptoms increased in the season in cases, which validated the questionnaire used in the previous cross sectional survey. 12 of 16 cases tested and seven of 15 controls showed a seasonal fall in PC20; the fall in the cases was significantly greater than in the controls. Peak flow charts showed no evidence of fall or of increased variability during the season. CONCLUSIONS: People who complained of symptoms in relation to the flowering of oilseed rape were rarely allergic to the plant and fewer than half were atopic. Nevertheless, they usually showed increased bronchial reactivity during the season, which may have been due in some cases to other allergens but in others to non-specific irritant effects of the air. Whether these are due to chemicals released by the crop, to rising summer ozone levels, or to other factors remains unclear.

Mevalonate availability affects human and rat resistance vessel function.

Previous data in rat conductance vessels indicated that cellular mevalonate contributes to vascular tone and systemic blood pressure control. Using exogenous mevalonate (M) or lovastatin, a 3-hydroxy-3-methyl-glutaryl CoA (HMG-CoA) reductase inhibitor (L), we characterized the role of mevalonate availability in resistance artery function, both in experimental animals and humans. Rat mesenteric artery resistance vessels (MARV, n = 9) were incubated for 48 h with either L, M, L + M, or vehicle (V) and tested for reactivity to NE, serotonin, acetylcholine, atrial natriuretic peptide, and sodium nitroprusside (SNP). Lovastatin increased sensitivity to NE (P < 0.03) and serotonin (P < 0.003), and significantly impaired the response to all three vasodilators. These effects were reversed by co-incubation with mevalonate. Mevalonate alone had no effect. In separate experiments, intravascular free Ca2+ concentration (ivfCa2+) was determined in fura-2AM loaded MARV. Basal ivfCa2+ was increased after a 48-h exposure to L (52.7 +/- 4.6 nM, L, vs. 29.7 +/- 2.4 nM, V, n = 12, P < 0.003), as were ivfCa2+ levels following stimulation with low (100 nM) NE concentrations. Similar ivfCa2+ concentrations were achieved during maximum contraction with NE (10 mM) in both groups. Human resistance arteries of human adipose tissue were also studied. Lovastatin increased the sensitivity to NE (ED50 = 372 +/- 56 nM, V, and 99 +/- 33 nM, L, P < 0.001) and significantly decreased the relaxation to acetylcholine and SNP of human vessels. We conclude that mevalonate availability directly contribute to resistance vessel function and vascular signal transduction systems in both experimental animals and humans. The study calls for the identification of non-sterol, mevalonate-derived vasoactive metabolites, and suggests that disorders of the mevalonate pathway can alter vascular tone and cause hypertension.

Oilseed rape and seasonal symptoms: epidemiological and environmental studies.

BACKGROUND: There is widespread concern that the cultivation of oilseed rape leads to seasonal epidemics of respiratory symptoms in populations living in the neighbourhood, and it has been suggested that the plant is a potent allergen. A study was therefore undertaken to determine the prevalence of seasonal symptoms in rural populations close to and far from areas of oilseed rape cultivation, and to measure the levels of allergen and other potentially harmful substances released by the crop. METHODS: Random samples of 1000 adults from the general practice populations of two villages surrounded by oilseed rape fields, and 1000 adults from one village far from such cultivation, were taken. The subjects completed a previously validated questionnaire on respiratory and other symptoms, including questions on symptom seasonality, occupation, and smoking habits. Pollen and fungal spore counts were made around fields of oilseed rape and in the villages. The chemicals released by oilseed rape were measured in the field. RESULTS: Overall, 86.8% of the subjects completed the questionnaires and the populations of the two samples were generally comparable. Spring and summer exacerbations of symptoms occurred equally in the two areas in approximately 25% of the population. There were small but significant excesses of cough, wheeze, and headaches in spring in the oilseed rape area (2.3% v 1.1%, 6.8% v 4.6%, and 4.8% v 2.8%, respectively), and cough, wheeze, and itchy skin were more prevalent in smokers. Counts of oilseed rape pollen were generally low except adjacent to fields, and counts of fungal spores were mostly higher in the rape than the non-rape areas. Oilseed rape was shown to give off terpenes and these were detected close to fields. CONCLUSIONS: While it is likely that a proportion of the spring symptoms occurring in people living in close proximity to oilseed rape is caused by the plant, the excess of such symptoms is small. This, together with the low levels of pollen in the area, suggests that allergy to oilseed rape pollen is uncommon. The general prevalence of seasonal symptoms in rural areas is of interest, and a proportion of these cases is likely to be caused by factors other than allergy. Release of chemicals by plants and natural rises in summer ozone levels may be contributors.

Cooling augments human saphenous vein reactivity to electrical stimulation.

Human saphenous veins were obtained at operation and assayed immediately (n = 10). The veins were cut into rings, suspended in organ chambers, and connected to force transducers for recording of isometric tension. One ring served as control; others were treated with either the alpha 1-adrenoceptor antagonist prazosin (Pz, 3 x 10(-7) M) or the alpha 2-adrenoceptor antagonist rauwolscine (Rw1, 10(-7) M). Cooling from 37 degrees to 24 degrees C had no significant effect on the resting tone of quiescent rings. Electrical stimulation (0.2-16 Hz) caused frequency-dependent contractions in control vessels. The contractions were inhibited by Pz (p < 0.001) and by Rw (p < 0.001). In control rings, cooling potentiated contractions evoked at all frequencies. Similar augmentations were induced by cooling in rings treated with the alpha 1-antagonist Pz. In contrast, rings treated with Rw before being electrically stimulated showed no significant change in contractile force when cooled. The data indicate that in the human saphenous vein, both alpha 1- and alpha 2-adrenoceptors are innervated, contributing to contractile response evoked by neuronal excitation. Cold augments saphenous vein reactivity to endogenously released norepinephrine (NE) by an apparent increase in the responsiveness of alpha 2-adrenoceptors to agonists. This relationship between temperature and adrenoceptor responsiveness is consistent with the hypothesized role of alpha 2-adrenoceptors in cold-induced vasospasm.

Hemidiaphragm paralysis: CT diagnosis.

We describe the use of computed tomography (CT) in diagnosing and documenting diaphragmatic paralysis in a patient with right lung cancer that invaded the mediastinum. The patient was unable to breath hold during CT scanning, and the images were degraded by motion artifact. Motion artifact, however, was noted only in the left lung. In patients with suspected phrenic nerve dysfunction who are having chest CT for any reason, we suggest obtaining several dynamic images at the lung bases during forced exhalation. The lack of motion artifact in the lung parenchyma may be useful for diagnosing phrenic nerve injury and hemidiaphragm paralysis.

The renin-angiotensin system in the type II diabetic obese Zucker rat.

Recently, the obese Zucker rat (OZR), an animal model of non-insulin-dependent (type II) diabetes, was shown to respond to converting enzyme inhibition with decreased albuminuria and a marked attenuation of glomerular injury. It was hypothesized that the OZR would possess low plasma renin values and an increased vascular responsiveness to angiotensin II, and therefore, the renin-angiotensin system (PRA, active renin, inactive renin, renal renin content, and plasma angiotensinogen) and vascular reactivity in OZR at 10 and 24 wk of age were investigated. PRA and renin concentration, inactive plasma renin, and renal renin content were all significantly (P < 0.05) reduced in OZR when compared with age-matched lean controls. The ratio of inactive to total renin was significantly increased in the OZR. OZR aortic ring vascular reactivity to KCl, norepinephrine, and angiotensin II was assessed. Despite essentially equal or increased contractile responses to KCl and norepinephrine at both 10 and 24 wk of age, the OZR was not more sensitive to angiotensin II and displayed a significantly reduced contractile response to angiotensin II at 24 wk of age, when compared with lean age-matched controls. It was concluded that the renal protective effect of converting enzyme inhibition in OZR, despite significantly reduced PRA and concentration, inactive plasma renin, and renal renin content, may not be due to a diabetes-induced increased vascular reactivity to angiotensin II.

Perimalleolar subcutaneous tissue pressure effects of elastic compression stockings.

PURPOSE: We hypothesized that the clinical benefit of elastic compression stockings (ECS) is at least in part due to an increase in subcutaneous pressure that may promote resorption of extracellular fluids, providing more efficient diffusion of oxygen and nutrients from the microcirculation to the skin and subcutaneous tissues. METHODS: To test this hypothesis we designed and standardized a device for measuring subcutaneous pressure in patients. We then measured the supine perimalleolar subcutaneous pressure from a single limb in four groups: group 1 consisted of control subjects (n = 8); group 2 consisted of patients with varicose veins and superficial venous insufficiency without lipodermatosclerosis or edema (n = 5); group 3 consisted of patients with deep venous insufficiency and lipodermatosclerosis but without edema (n = 8); and group 4 consisted of patients with deep venous insufficiency, lipodermatosclerosis, and clinically evident edema (n = 8). Measurements were made at baseline and after application of 20 to 30 mm Hg and 30 to 40 mm Hg ECS. RESULTS: There was no significant difference in the baseline subcutaneous pressure between the three groups without clinical edema (p > 0.05). Baseline perimalleolar pressure was elevated, however, in group 4 patients compared with groups 1, 2, and 3 (p < 0.05). All three groups with chronic venous insufficiency (CVI) (groups 2, 3, 4) demonstrated increases in subcutaneous pressure with application of ECS, which was statistically significant in groups 3 and 4. There was no difference between the increase in perimalleolar subcutaneous pressure induced by 20 to 30 mm Hg or 30 to 40 mm Hg ECS in groups 3 and 4. CONCLUSIONS: Patients with CVI and edema have significant elevations in supine resting perimalleolar subcutaneous pressure compared with control subjects and patients with CVI without edema. Twenty to 30 mm Hg and 30 to 40 mm Hg ECS increased measured perimalleolar subcutaneous pressure in patients with CVI with and without clinical edema but not in control patients. These results suggest the mechanism of benefit of ECS in patients with CVI is due at least in part to an increase in subcutaneous pressure that may act to promote more efficient absorption of perimalleolar extracellular fluid.

The roentgenographic findings associated with air embolism in sport scuba divers.

Records on all patients with arterial gas embolism (AGE) presenting to UCSD from 1982-1989 and for whom chest radiographs were available were reviewed. Of the 31 patients, 13 roentgenograms (42%) showed evidence of pulmonary barotrauma demonstrated by pneumomediastinum (N = 8), subcutaneous emphysema (N = 3), pneumocardium (N = 2), pneumoperitoneum (N = 1), or pneumothorax (N = 1). Pneumopericardium was not seen. Sixteen (52%) of the 31 patients had pulmonary infiltrates. Radiographic evidence of barotrauma was on occasion subtle, and in four cases was overlooked. Evidence of barotrauma (i.e., extra-alveolar air) was often identified along the left cardiac border, aortic arch, descending aorta, and hilar vessels. Subtle findings of ectopic air can confirm the clinical diagnosis of AGE; however, radiographic evidence of concomitant near drowning occurs more frequently.

Human saphenous vein grafts explanted from the arterial circulation demonstrate altered smooth-muscle and endothelial responses.

PURPOSE: Animal models have been used to assess the function of vascular smooth muscle and endothelium of veins grafted into arterial circulation. The primary model consists of grafting the external jugular vein into the carotid artery of the rabbit. These studies suggest a selective increase in the responsiveness of the grafted veins to serotonin. However, in both human cardiac and peripheral vascular operations, the saphenous, not the jugular, is the vein most frequently used. Thus the propriety of the rabbit model is unknown. METHODS: Human saphenous veins and vein grafts were obtained from patients undergoing leg vein bypass graft revisions (n = 8). The reversed vein grafts were placed into arterial circulation for periods ranging from 4 to 26 months before removal (mean 16 months). All vessels were immediately cut into rings and suspended in organ chambers for recording isometric contractions to norepinephrine and serotonin. RESULTS: The maximal contractions elicited by both norepinephrine and serotonin were reduced in human vein grafts in comparison to the results in human saphenous vein (maximal response to norepinephrine 1.42 +/- 0.34 gm [vein graft] vs 4.59 +/- 1.13 gm [saphenous vein], p = 0.031; maximal response to serotonin 2.68 +/- 0.58 gm [vein graft] vs 4.72 +/- 1.11 gm [saphenous vein], p = 0.042). Human vein grafts were less responsive to norepinephrine than was saphenous vein (negative log of concentration that caused 50% of the maximal response -5.91 +/- 0.10 and -6.84 +/- 0.22, respectively; p < 0.009). After precontraction with norepinephrine (to 30% of the maximal response), saphenous vein, but not vein grafts, demonstrated endothelium-dependent relaxation to acetylcholine (maximum relaxation 27.4% +/- 6.8%; p = 0.001). CONCLUSIONS: Human saphenous veins grafted into arterial circulation exhibit loss of endothelium-dependent relaxation to acetylcholine and diminished contractions to agonists (norepinephrine and serotonin). In contrast to rabbit data, serotonin elicits dose-dependent contractions in both human saphenous vein and human vein grafts. Since the vascular wall contractility varies widely across species, the relevance of rabbit vein graft data to human bypass grafts is uncertain.

Occupational accidents presenting to the accident and emergency department.

A prospective survey of patients attending the major Accident and Emergency Department in Aberdeen was undertaken. This department serves a population of 500,000 and sees some 50% of all accidents in the region. All work-related injuries were identified and information relating to the circumstances of the accident, injury sustained, and treatment required was sought. Work-related injuries accounted for 16.5% of new patients attending the department. The commonest injury type was a laceration to a finger. Three hundred and eighty diagnostic X-rays were undertaken and a total of 910 treatments were required over a 27-day period. On an annual basis, it is estimated that some 5100 radiographs and 12,300 medical treatments would be required for work-related accidents. It is estimated that 30% of injuries to the hands and feet would have been prevented by the wearing of appropriate personal protective equipment. The majority of workplace accidents were correctly referred to A&E and any efforts to reduce this workload must concentrate on preventive measures in the workplace. This paper suggests that documenting work-related accidents and determining targets for preventive action would reduce the number of attendances at A&E units with a potential significant saving for industry and the National Health Service.

Linkage maps in pea.

We have analyzed segregation patterns of markers among the late generation progeny of several crosses of pea. From the patterns of association of these markers we have deduced linkage orders. Salient features of these linkages are discussed, as is the relationship between the data presented here and previously published genetic and cytogenetic data.

Percutaneous drainage of tubo-ovarian abscesses.

The authors performed percutaneous drainage of 27 tubo-ovarian abscesses (TOAs) in 16 patients in whom medical therapy with triple antibiotics prior to catheter drainage had not been successful. Percutaneous drainage was successful in 15 of 16 patients (94%). One patient underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy 3 days after catheter placement because of persistent symptoms and lack of drainage from the catheter; at laparotomy, a large infected phlegmon was found. Two patients had recurrent disease at 3 and 4 months after catheter placement. Bilateral salpingectomy was performed in one patient and total abdominal hysterectomy and bilateral salpingo-oophorectomy in the other. One of these patients had cervical carcinoma, and the other had a long history of recurrent pelvic inflammatory disease and TOAs. The long-term avoidance of surgery was 81.2%. Access routes for catheter drainage were through the anterior abdominal wall for 10 abscesses, through the posterior transgluteal route for 11, and through the transvaginal route for six. Duration of drainage was 1-20 days (mean, 6 days). Complications consisted of transient sciatic pain in two patients and mild bacteremia in one. The results indicate that percutaneous drainage of TOAs is effective in patients in whom medical therapy is not successful.