Influence of patients' expectations on antibiotic management of acute lower respiratory tract illness in general practice: questionnaire study

OBJECTIVE

To assess patients' views and expectations when they consult their general practitioner with acute lower respiratory symptoms and the influence these have on management.

DESIGN

General practitioners studied consecutive, previously well adults and recorded clinical data, the certainty regarding their prescribing decision, and the influence of non-clinical factors on that decision. Patients completed a questionnaire at home after the consultation.

SETTING

76 doctors from suburban, inner city, and rural practices.

SUBJECTS

1014 eligible patients entered; 787 (78%) returned the questionnaire.

MAIN OUTCOME MEASURES

The views of the patient, the views of and antibiotic prescription by the doctor.

RESULTS

Most patients thought that their symptoms were caused by an infection (662) and that antibiotics would help (656) and had both wanted (564) and expected (561) such a prescription. 146 requested an antibiotic, 587 received one. Of the 643 patients who thought they had an infection, 582 wanted an antibiotic and thought it would help. Severity of symptoms did not relate to wanting antibiotics. For those prescribed antibiotics, their doctor thought they were definitely indicated in only 116 cases and not indicated in 126. Patient pressure most commonly influenced the decision to prescribe even when the doctor thought antibiotics were not indicated. Doctors considered antibiotics definitely indicated in only 1% of the group in whom patient pressure influenced the prescribing decision. Patients who did not receive an antibiotic that they wanted were much more likely to express dissatisfaction. Dissatisfied patients reconsulted for the same symptoms twice as often as satisfied patients.

CONCLUSION

Patients presenting with acute lower respiratory symptoms often believe that infection is the problem and antibiotics the answer. Patients' expectations have a significant influence on prescribing, even when their doctor judges that antibiotics are not indicated.

Prospective study of the incidence, aetiology and outcome of adult lower respiratory tract illness in the community

BACKGROUND

Acute lower respiratory tract illness in previously well adults is usually labelled as acute bronchitis and treated with antibiotics without establishing the aetiology. Viral infection is thought to be the cause in most cases. We have investigated the incidence, aetiology, and outcome of this condition.

METHODS

Previously well adults from a stable suburban population consulting over one year with a lower respiratory tract illness were studied. For the first six months detailed investigations identified predetermined direct and indirect markers of infection. Evidence of infection was assessed in relation to presenting clinical features, indirect markers of infection, antibiotic use, and outcome.

RESULTS

Consultations were very common, particularly in younger women (70/1000 per year in previously well women aged 16-39 years), mainly in the winter months; 638 patients consulted, of whom 316 were investigated. Pathogens were identified in 173 (55%) cases: bacteria in 82 (Streptococcus pneumoniae 54, Haemophilus influenzae 31, Moraxella catarrhalis 7), atypical organisms in 75 (Chlamydia pneumoniae 55, Mycoplasma pneumoniae 23), and viruses in 61 (influenza 23). Seventy nine (24%) had indirect evidence of infection. Bacterial and atypical infection correlated with changes in the chest radiograph and high levels of C reactive protein but not with (a) the GP's clinical assessment of whether infection was present, (b) clinical features other than focal chest signs, and (c) outcome, whether or not appropriate antibiotics were prescribed.

CONCLUSIONS

Over 50% of patients have direct and/or indirect evidence of infection, most commonly bacterial and atypical pathogens, but the outcome is unrelated to the identified pathogens. Many patients improve without antibiotics and investigations do not help in the management of these patients. GPs can reassure patients of the causes and usual outcome of this self-limiting condition.

Dead men and radiologists don't lie: a review of cadaveric and radiological studies of rotator cuff tear prevalence

INTRODUCTION

Rotator cuff tears are a common pathology, with a varied prevalence reported.

PATIENTS AND METHODS

A literature review was undertaken to determine the cadaveric and radiological (ultrasonography and magnetic resonance imaging [MRI]) prevalence of rotator cuff tear. The radiological studies were subdivided into symptomatic and asymptomatic subjects.

RESULTS

Cadaveric rotator cuff tears were found in 4629 shoulders of which only 2553 met the inclusion criteria. The prevalence of full-thickness tears was 11.75% and partial thickness 18.49% (total tears 30.24%). The total tear rate in ultrasound asymptomatic was 38.9% and ultrasound symptomatic 41.4%. The total rate in MRI asymptomatic was 26.2% whilst MRI symptomatic was 49.4%.

DISCUSSION

The unselected cadaveric population should contain both symptomatic and asymptomatic subjects. A prevalence of tears between the symptomatic and asymptomatic radiological groups would be expected. However, apart from the MRI asymptomatic group, the radiological prevalence of rotator cuff tears exceeds the cadaveric.

CONCLUSIONS

Rotator cuff tears are frequently asymptomatic. Tears demonstrated during radiological investigation of the shoulder may be asymptomatic. It is important to correlate radiological and clinical findings in the shoulder.

Cauda equina syndrome: what is the relationship between timing of surgery and outcome?

The role of urgent surgery in improving the outcome of cauda equina compression following lumbar central disc prolapse remains controversial. Some series claim improved outcome from emergency decompression whilst others have found no benefit. Resolution of this issue is important because the opportunity to reverse neurological impairment may already have been lost by the time of hospital admission. Removal of a large central disc prolapse can be considerably more difficult than routine discectomy, and may require an extensive exposure. When performed under less than optimal conditions, as often exists in the emergency setting, surgery may even add to rather than alleviate morbidity. This article reviews the pathophysiology of cauda equina syndrome, its definition, and the controversies surrounding management. Where urinary retention with overflow incontinence extists at presentation we believe that urgent decompression confers no benefit.

Symptoms arising from Double-J ureteral stents

We investigated whether use of the Double-J ureteral stent causes untoward symptoms and complications. Of 20 patients evaluated by questionnaire 18 suffered 1 or more symptoms in the upper (for example loin pain) or lower (for example dysuria and frequency) urinary tract in the absence of infection. Despite the undoubted benefit in many patients, troublesome symptoms are common. We recommend early removal of the stents but we cannot implicate any correctable technical factors.

The role of neuroeffector mechanisms in cerebral hyperperfusion syndromes

Cerebral hyperperfusion, a state in which blood flow exceeds the metabolic needs of brain, may complicate a number of neurological and neurosurgical conditions. It may account for the propensity with which hemorrhage, cerebral edema, or seizures follow embolic stroke, carotid endarterectomy, or the excision of large arteriovenous malformations, and for some of the morbidity that accompanies acute severe head injury, prolonged seizures, and acute severe hypertension. Hyperperfusion syndromes have in common acute increases in blood pressure, vasodilatation, breakdown of the blood-brain barrier, and the development of cerebral edema. These common features suggest the possibility that they share the same pathogenic mechanisms. It was believed until recently that reactive hyperemia was caused primarily by the generation of vasoactive metabolites, which induced vasodilatation through relaxation of vascular smooth muscle. However, the authors have recently established that the release of vasoactive neuropeptides from perivascular sensory nerves via axon reflex-like mechanisms has a significant bearing upon a number of hyperperfusion syndromes. In this article, the authors summarize their data and discuss possible therapeutic implications for blockade of these nerves or their constituent neuropeptides.

Mortality in patients with diabetic neuropathic osteoarthropathy (Charcot foot)

OBJECTIVE

To determine the mortality of a population of patients diagnosed with Charcot neuropathic osteoarthropathy managed by a single specialist unit and to compare the results with a control population.

METHODS

We have undertaken a retrospective analysis of all cases of Charcot foot on the comprehensive database which has been maintained at the specialist diabetic foot clinic at the City Hospital, Nottingham since 1982. Survival and the incidence of amputation (major and minor) was compared with a control population referred with uncomplicated neuropathic ulceration. Controls were individually matched for gender, age (+/-2 years), disease type, disease duration (+/-2 years) and year of referral (+/-3 years).

RESULTS

Forty-seven cases (21 female, 26 male) of Charcot foot were identified, of whom 18 (38.3%) had Type 1 diabetes. Mean age and disease duration at presentation were 59.2 +/- 13.4 (sd) and 16.2 +/- 11.2 years, compared with 59.7 +/- 12.6 and 16.3 +/- 11.2 years, respectively, in the controls. Twenty-one (44.7%) of those with Charcot had died, after a mean interval of 3.7 +/- 2.8 years. This compared with 16 (34.0%) after a mean 3.1 +/- 2.7 years in the control group. Mean duration of follow-up in the survivors was 4.7 +/- 4.9 years (Charcot) and 5.3 +/- 3.9 years (controls). A total of 11 (23.4%) Charcot patients had had a major amputation on the side of the index lesion, compared with five (10.6%) controls. There was no difference between the two groups (P > 0.05, Chi-square).

CONCLUSIONS

The mortality in this group of patients with Charcot foot was higher than expected. Nevertheless, there was no difference between those with Charcot and those with uncomplicated neuropathic ulceration. It is possible that it is neuropathy, rather than Charcot osteoarthropathy, which is independently associated with increased mortality in diabetes. The mechanism underlying any such association is not known. There is a need for a formal, prospective, multicentre study to investigate the life expectancy and cardiovascular risk of those with Charcot osteoarthropathy.

Surgery for acoustic neurinoma. An analysis of 100 translabyrinthine operations

A consecutive series of 100 translabyrinthine operations for removal of acoustic neurinoma is reported. Complete tumor removal was achieved in 97% of cases. There were three perioperative deaths, and the postoperative morbidity rate was low. The facial nerve was preserved anatomically in 82% of patients. Preoperative facial weakness and tumor size larger than 2.5 cm were predictive of poor facial recovery. In patients with an intact nerve but complete facial palsy 1 week after surgery, electroneuronography was a good predictor of the final facial outcome and may influence the timing of rehabilitative procedures. With the exception of patients who have small tumors and good speech discrimination (where a suboccipital approach may preserve hearing acuity), the translabyrinthine operation is the procedure of choice for removal of acoustic neurinomas in patients who have normal hearing in the contralateral ear.

Measurement of cerebrovascular changes in cats after transient ischemia using dynamic magnetic resonance imaging

BACKGROUND AND PURPOSE

Hemodynamic changes associated with acute ischemia cannot be measured with conventional nuclear magnetic resonance imaging. In this study, we used dynamic susceptibility-contrast magnetic resonance imaging to measure the changes in vascular transit time and relative cerebral blood volume in a feline occlusion-reperfusion model.

METHODS

Dynamic susceptibility-contrast measurements were obtained before and during 10 minutes of global cerebral ischemia and for up to 3 hours after the onset of reperfusion. A cerebral blood flow index was calculated from the vascular transit time and relative cerebral blood volume measurements. Functional maps were constructed to demonstrate the regional hemodynamic differences resulting from the induced ischemia.

RESULTS

During the early phase after reperfusion, both the relative cerebral blood volume and blood flow index rose sharply, followed by a fall to near-basal levels at 45 minutes (1 x control and 1.3 x control, respectively). Thereafter, the volume rose slowly, whereas the flow index continued to drop. At 3 hours, cerebral blood volume had reached 1.6 times its control value, whereas the flow index had returned to its base value.

CONCLUSIONS

The hemodynamic behavior we observed in our model reflects the independent responses of the cerebral blood volume and flow index to ischemic insult. Measurements acquired by our method were consistent with the temporal behavior reported in previous radionuclide studies. Susceptibility-contrast nuclear magnetic resonance tomographic imaging proved to be valuable in detecting and quantifying both immediate and subsequent changes in the hemodynamic state of the ischemic and hyperemic feline brain.

Surgery of the lateral skull base: a 50-year endeavour

Disregarding the widely used division of skull base into anterior and lateral, since the skull base should be conceived as a single anatomic structure, it was to our convenience to group all those approaches that run from the antero-lateral, pure lateral and postero-lateral side of the skull base as “Surgery of the lateral skull base”. “50 years of endeavour” points to the great effort which has been made over the last decades, when more and more difficult surgeries were performed by reducing morbidity. The principle of lateral skull base surgery, “remove skull base bone to approach the base itself and the adjacent sites of the endo-esocranium”, was then combined with function preservation and with tailoring surgery to the pathology. The concept that histology dictates the extent of resection, balancing the intrinsic morbidity of each approach was the object of the first section of the present report. The main surgical approaches were described in the second section and were conceived not as a step-by-step description of technique, but as the highlighthening of the surgical principles. The third section was centered on open issues related to the tumor and its treatment. The topic of vestibular schwannoma was investigated with the current debate on observation, hearing preservation surgery, hearing rehabilitation, radiotherapy and the recent efforts to detect biological markers able to predict tumor growth. Jugular foramen paragangliomas were treated in the frame of radical or partial surgery, radiotherapy, partial “tailored” surgery and observation. Surgery on meningioma was debated from the point of view of the neurosurgeon and of the otologist. Endolymphatic sac tumors and malignant tumors of the external auditory canal were also treated, as well as chordomas, chondrosarcomas and petrous bone cholesteatomas. Finally, the fourth section focused on free-choice topics which were assigned to aknowledged experts. The aim of this work was attempting to report the state of the art of the lateral skull base surgery after 50 years of hard work and, above all, to raise questions on those issues which still need an answer, as to allow progress in knowledge through sharing of various experiences. At the end of the reading, if more doubts remain rather than certainties, the aim of this work will probably be achieved.

Contemporary use of antibiotics in 1089 adults presenting with acute lower respiratory tract illness in general practice in the U.K.: implications for developing management guidelines

Respiratory symptoms are the most common cause of general practitioner (GP) consultation, and hospital-based specialists are often called on to provide management guidelines, particularly in the area of antibiotic prescribing. The present authors have assessed factors associated with antibiotic use by 115 GPs when managing 1089 adults with an acute lower respiratory tract illness, including cough. They prescribed antibiotics to three-quarters of patients, but felt antibiotics to be definitely indicated in less than one-third of these cases and not needed in one-fifth. Univariate analysis revealed that antibiotics were prescribed more frequently by older GPs for older patients in the presence of underlying disease, discoloured sputum, shortness of breath, wheeze, fever, signs on chest examination, and 'other factors'. Multivariate logistic regression confirmed an independent effect for all these findings except for the presence of underlying disease, shortness of breath and wheeze. 'Other factors' included patient 'pressure' and social factors, and GP work pressure or prior experience with the patient. These factors were an important influence on prescribing, especially if the GP felt an antibiotic was not indicated. Amoxycillin was the first choice (58% of total) except where the patient had recently received antibiotics for the same illness. Broader spectrum antibiotics were used more commonly in patients with chronic lung disease, discoloured sputum, chest signs on examination and where the GP felt antibiotics were indicated. However, these antibiotics were also prescribed to 14% of previously well patients. General practitioners used a wide variety of terms to describe the illness with little consistency or structure. The decision concerning the use and choice of antibiotics and the confidence with which the GP makes that decision is a complex interaction between patient, doctor and disease, being affected not only by clinical features but also by the social and psychological elements of the presenting problem. Such issues need to be appreciated by hospital specialists when called on to advise on developing relevant guidelines for primary care.

Chronic trigeminal ganglionectomy or topical capsaicin application to pial vessels attenuates postocclusive cortical hyperemia but does not influence postischemic hypoperfusion

Marked hyperemia accompanies reperfusion after ischemia in the brain, and may account for the propensity of cerebral hemorrhage to follow embolic stroke or carotid endarterectomy, and for the morbidity that follows head injury or the ligation of large arteriovenous malformations. To evaluate the contribution of trigeminal sensory fibers to the hyperemic response, CBF was determined in 12 symmetrical brain regions, using microspheres with up to five different isotopic labels, in four groups of cats. Measurements were made at 15-min intervals for up to 2 h of reperfusion after global cerebral ischemia induced by four-vessel occlusion combined with systemic hypotension of either 10- or 20-min duration. In normal animals, hyperemia in cortical gray matter 30 min after reperfusion was significantly greater after 20 min (n = 10) than after 10 min (n = 7) of ischemia (312 ml/100 g/min versus 245 ml/100 g/min; p less than 0.01). CBF returned to preischemic levels approximately 45 min after reperfusion and was reduced to approximately 65% of basal CBF for the remaining 75 min. In cats subjected to chronic trigeminal ganglionectomy (n = 15), postocclusive hyperemia in cortical gray matter was attenuated by up to 48% on the denervated side (249 versus 150 ml/100 g/min; p less than 0.01) after 10 min of ischemia. This effect was maximal in the middle cerebral artery (MCA) territory, and was confined to regions known to receive a trigeminal innervation. In these animals, substance P (SP) levels in the MCA were reduced by 64% (p less than 0.01), and the density of nerve fibers containing calcitonin gene-related peptide (but not vasoactive intestinal polypeptide or neuropeptide Y) was decreased markedly on the lesioned side. Topical application of capsaicin (100 nM; 50 microliters) to the middle or posterior temporal branch of the MCA 10-14 days before ischemia decreased SP levels by 36%. Postocclusive hyperemia in cortical gray matter was attenuated throughout the ipsilateral hemisphere by up to 58%, but the cerebral vascular response to hypercapnia (PaCO2 = 60 mm Hg) was unimpaired. The duration of hyperemia and the severity of the delayed hypoperfusion were not influenced by trigeminalectomy, capsaicin application, or the intravenous administration of ATP. These data demonstrate the importance of neurogenic mechanisms in the development of postischemic hyperperfusion, and suggest the potential utility of strategies aimed at blocking axon reflex-like mechanisms to reduce severe cortical hyperemia.

Encephaloceles of the anterior cranial fossa

From a total of 114 encephaloceles treated surgically at The Hospital for Sick Children in the 15 years to 1994, the case records of 17 patients with sincipital and 5 patients with basal defects were reviewed retrospectively. The condition was evident at birth in 64% of patients, while the remainder presented with either cerebrospinal fluid (CSF) rhinorrhea, nasal obstruction, or feeding difficulty. Hypertelorism affected 73% of patients. All encephaloceles were repaired transcranially, at a mean age of 2 years, usually by means of an intradural pericranial graft. Five children with gross hypertelorism underwent orbital translocation at the time of encephalocele repair. Of those not corrected, primary and secondary hypertelorism regressed in most instances where the encephalocele was treated before the age of 2 years. There were no deaths. The only case of CSF rhinorrhea occurred in a patient with a basal defect, in whom intradural repair was not possible because of adherence of diencephalic structures to the sac wall. Hypertelorism recurred in 1 patient after orbital translocation, requiring recorrection 2 years later. One patient with untreated secondary hypertelorism failed to regress after the encephalocele was excised at the age of 4 months. Developmental outcome was normal in 59% of children, whilst 18% have mild mental or physical disability, and 23% are severely impaired. A child with a sincipital or basal defect and mild hypertelorism should have the encephalocele treated in early childhood to allow the facial skeleton to remodel with growth. When an encephalocele is accompanied by gross hypertelorism or a facial cleft, one-stage correction can be undertaken safely in early childhood with minimal mortality and acceptable morbidity.

Dissolution of porcine incisor pulps in sodium hypochlorite solutions of varying compositions and concentrations

BACKGROUND

The solubility of dental pulp tissue in sodium hypochlorite has been extensively investigated but results have been inconsistent; due most likely to variations in experimental design, the volume and/or rate of replenishment of the solutions used and the nature of the tissues assessed. Traditionally, the sodium hypochlorite solutions used for endodontic irrigation in Australia have been either Milton or commercial bleach, with Milton being the most common. Recently, a range of Therapeutic Goods Administration (TGA) approved proprietary sodium hypochlorite solutions, which contain surfactant, has become available. Some domestic chlorine bleaches now also contain surfactants. The purpose of this study was to perform new solubility assessments, comparing Milton with new TGA approved products, Hypochlor 1% and Hypochlor 4% forte, and with a domestic bleach containing surfactant (White King).

METHODS

Ten randomly assigned pulp samples of porcine dental pulp of approximately equal dimensions were immersed in the above solutions, as well as representative concentrations of sodium hydroxide. Time to complete dissolution was measured and assessed statistically.

RESULTS

White King 4% showed the shortest dissolution time, closely followed by Hypochlor 4% forte. White King 1% and Hypochlor 1% each took around three times as long to completely dissolve the samples of pulp as their respective 4% concentrations, while Milton took nearly 10 times as long. The sodium hydroxide solutions showed no noticeable dissolution of the pulp samples.

CONCLUSIONS

The composition and content of sodium hypochlorite solutions had a profound effect on the ability of these solutions to dissolve pulp tissue in vitro. Greater concentrations provided more rapid dissolution of tissue. One per cent solutions with added surfactant and which contained higher concentrations of sodium hydroxide were significantly more effective in dissolution of pulp tissue than Milton.

Absence of the greater sphenoid wing in neurofibromatosis type I: congenital or acquired: case report

unilateral absence of the greater wing of the sphenoid bone is a distinctive but uncommon manifestation of Type I neurofibromatosis, which has until now been regarded as a developmental anomaly of mesodermal origin. A computed tomographic scan was obtained in a 4-week-old infant with an abnormal left eye. The scan demonstrated an intact ipsilateral sphenoid bone, except for minor expansion of the medial end of the left superior orbital fissure. Another computed tomographic scan was obtained 6 years later, when the child had café-au-lait patches, axillary freckling, Lisch nodules, and left phthisis bulbi. This later scan showed typical sphenoid dysplasia. Much of the greater wing was absent, and the anterior temporal pole was displaced anteriorly. In this article, we discuss the implications of this case in terms of the cause of this condition and the diagnosis of Type I neurofibromatosis.

Outcome of translabyrinthine surgery for vestibular schwannoma in neurofibromatosis type 2

OBJECTIVES

To analyse the long-term outcome of translabyrinthine surgery for vestibular schwannoma (VS) in neurofibromatosis type 2 (NF2). RESEARCH TYPE: Retrospective cohort study.

SETTING

Two tertiary referral NF2 units.

PATIENTS

One hundred and forty eight translabyrinthine operations for patients with VS were performed. Preoperative stereotactic radiotherapy had been performed on 12(9.4%) patients.

RESULTS

Mean tumour size was 3.1 cm. Total tumour excision was achieved in 66% of cases, capsular remnants were left in 24% of cases, and subtotal excision was achieved in 5% and partial removal was achieved in 5%. The radiological residual/recurrence rate was 13.9%. The perioperative mortality was 1.6%. At 2 years postoperatively, facial function was expressed in terms of House-Brackmann score (HB): HB 1 in 53.4%, HB 1/2 in 61.3%, HB 1-3 in 83.2% and HB 4-6 in 16.8%. All nine patients who underwent surgery following failed stereotactic radiotherapy had HB 3 function or better. Among 9.5% of the cases, 14 facial nerves were lost during surgery and repaired using direct anastomosis or grafting. There was no tinnitus present preoperatively in 27% of the cases, and 22% of patients developed tinnitus postoperatively. In patients with preoperative tinnitus, 61% remained the same, 17% got it resolved and only in 21% it worsened. The preoperative hydrocephalus rate was 26%, and among 15% of the cases five ventriculo-peritoneal (VP) shunts were performed. The cerebrospinal fluid leak rate was 2.5%. Fifty-six patients underwent auditory brainstem implantation (ABI) and two patients had cochlear implant (CI) sleepers inserted.

CONCLUSIONS

The management of patients with NF2 presents the clinician with a formidable challenge with many patients still presenting themselves late with the neurological compromise and a large tumour load. There is still an argument for the management by observation until the neurological compromise dictates interventional treatment particularly with the option of hearing rehabilitation with ABI or CI. The translabyrinthine approach provides a very satisfactory means of reducing the overall tumour volume.

Treatment of vasospasm with a 480-nm pulsed-dye laser

Laser energy at a wavelength of 480 nm was applied in 1-microseconds pulses of 3 to 10 mJ to two models of vasospasm. Rabbit common carotid arteries (CCA's) were constricted chronically by the application of human blood within a silicone sheath. Peak vasospasm developed 24 to 48 hours later, and persisted for up to 6 days. Endovascular laser treatment was delivered to 40 CCA's via a 200-microns diameter silica quartz fiber introduced through the femoral artery. The CCA caliber increased from 60% of the pre-vasospasm control diameter to a minimum post-laser diameter of 83% of control. No instances of laser-induced perforation or of arterial thrombosis were observed for up to 60 days after treatment. Prophylactic laser application to nine normal vessels was able to attenuate the development of vasospasm if blood was applied immediately thereafter (88% vs. 59% of control diameter, p less than 0.02), but not if blood was applied 7 days later. Studies in 16 normal CCA's established that there was a considerable margin between the laser energy required to induce dilatation and that which caused perforation, providing that the fiber remained relatively central within the artery. Morphological examination demonstrated focal loss of endothelial cells immediately after laser application, followed approximately 7 days later by the development of areas of intimal hyperplasia. Only minimal changes were observed in the medial or adventitial layers. In a second study, the basilar artery of seven dogs was constricted chronically by two intracisternal injections of autologous blood 3 days apart. Five dogs received endovascular laser treatment 7 or 10 days after the first injection, when basilar artery diameter was reduced to a mean of 61% and 77% of control, respectively. Immediately following treatment, basilar artery diameter increased to 104% and 102% of resting diameter, respectively. Both untreated and laser-treated arteries were smaller than the control diameter at 30 days (80% and 82%, respectively), but in each group the vasodilatory response to hypercapnia was preserved. These findings indicate that 1-microsecond laser pulses are well tolerated by systemic and cerebral arteries in two different animal models, and suggest that the 480-nm pulsed-dye laser may have an application for the treatment or prophylaxis of cerebral vasospasm.

Are varicose veins and coronary artery bypass surgery compatible?

In 35 legs being operated on for varicose veins a venogram showed that the part of the long saphenous vein below the knee does not undergo varicose dilatation. In 7 of the 9 examined postoperatively this segment remained patent after the vein above was stripped. Varicose veins resulting from saphenofemoral incompetence can be treated surgically by stripping the long saphenous vein only to the knee and yet still leave a non-varicose segment for future coronary artery bypass grafting.

Matrotrophic viviparity in the yellowtail rockfish Sebastes flavidus

A capacity for matrotrophic viviparity was established in the yellowtail rockfish Sebastes flavidus (Teleostei: Scorpaeniformes). The incorporation of radiolabel into embryos from [14C]phosphatidylcholine present in the maternal serum during gestation provided the first in vivo demonstration of matrotrophy of phospholipid for any viviparous teleost and of any nutrient for a member of the genus Sebastes. Radiolabel content increased as embryos progressed through ontogeny. Serum proteins of 170 kDa, present in vitellogenic and embryogenic females, but not in earlier stages, in immature females or in males, indicated the presence of vitellogenin in pregnant females and, thus, the potential for matrotrophic supplementation to yolk sequestered before fertilization. The retention of higher molecular mass proteins and highly phosphorylated proteins and the maintenance of total protein content in yolk during early to mid embryogenesis argue for exogenous maternal supply during gestation. As ovarian development proceeded from the oocyte through successive embryonic stages, the distribution of yolk proteins shifted from higher (67­97 kDa) to lower molecular masses (<70 kDa). The results of these experimental studies corroborate data from field investigations showing that yellowtail rockfish can matrotrophically supplement embryo nutrients obtained before fertilization. Thus, yellowtail rockfish represent a teleost species positioned within the viviparity continuum and not at its extremes.

Villous tumours of the large bowel

A series of 110 patients with villous tumours of the colon and rectum treated by a single surgeon over an 18-year period is reported. Multiple lesions were present in 15 per cent of patients and 24 per cent of cases contained invasive malignancy, of which 83 per cent were Dukes' A. The major lesion was in the rectum in 84 per cent of patients and in the sigmoid colon in 12 per cent. Rectal bleeding and diarrhoea were the most common presenting symptoms; 6 per cent of patients were asymptomatic. Digital assessment proved a more reliable indicator of the presence of malignancy than either random biopsy or barium enema. In all, 70 of 76 (92 per cent) benign rectal lesions and 15 of 22 (68 per cent) malignant rectal lesions were successfully removed by peranal submucous excision or snaring and none of the malignancies so treated has developed a recurrence to date. Benign recurrence has developed in 13 per cent of all patients; the majority appeared within 4 years and were at the same level as the initial lesion. Of the 79 patients with benign tumours 7.6 per cent have subsequently developed large bowel carcinomas, after 2-16 years; all were symptomatic, half were at the same level as the previous benign lesion, and half were suitable for peranal removal.

Two-color holography in reduced near-stoichiometric lithium niobate

We explored a number of factors affecting the properties relevant to holographic optical data storage by using a two-color recording scheme in reduced, near-stoichiometric lithium niobate. Two-color, or photon-gated, recording is achieved by use of 852-nm information-carrying beams and 488-nm gating light. Readout at 852 nm is nondestructive, with a gating ratio of ~10(4). Recording sensitivity, gating ratio, dynamic range, and dark decay were measured for crystals of differing stoichiometry, degree of reduction, wavelength of the gating light, temperature, and optical power density. The two-color sensitivity per incident photon is still somewhat less than that of the one-color process at 488 nm for ~1 W/cm(2) of gating light but is essentially the same in terms of absorbed photons. Two-color recording is an attractive way of achieving nondestructive readout in a read-write material, and it allows selective optical erasure.

Wound closure after acoustic neuroma surgery

Cerebrospinal fluid leakage from the wound or middle ear cavity remains a common cause of morbidity after acoustic neuroma surgery, regardless of the operative route employed. An incidence of around 15% is reported in most large series. The authors describe a method of wound closure which is applicable to both translabyrinthine and retrosigmoid tumour excision. Adoption of this technique in 188 consecutive patients has reduced the incidence of this complication in our unit from 13% to 1.6%.