1604 Infection and Morbidity After Local Anaesthetic Intravesical Botox Treatment Without Prophylactic Antibiotics

Aim

Intravesical Botulinum Toxin Type A (BoNT-A) is a common treatment for overactive bladder symptoms refractory to anticholinergic and beta-3 agonist medications. Urinary tract infection rates of < 10% are commonly reported for flexible cystoscopy. We aimed to establish whether local anaesthetic flexible cystoscopy BoNT-A treatment could be performed with an acceptable rate of infection and morbidity without prophylactic antibiotics.

Method

Prospective audit of patients treated with local anaesthetic intravesical BoNT-A over 8 weeks. A telephone questionnaire was administered at 10 to 17 days post-procedure assessing symptoms, infection and antibiotic use. Electronic records were used to review pre-procedure urine analysis and post-procedure urine culture. Antibiotic use and positive cultures within 10 days were considered significant.

Results

51 (76%) of the 67 patients treated were contacted by telephone. These consisted of 41 female and 10 male patients with mean (range) age of 58 (25 to 86) years. 35 (69%) reported being asymptomatic or having symptoms as expected and 2 (4%) patients reported symptoms worse than expected following the procedure. 14 (27%) reported having a urinary tract infection with 9 (18%) provided with antibiotics. Positive urine cultures were present in 5 (10%) patients. Pre-procedure urine analysis, patient age, history of recurrent infection and catheter use did not predict post-procedure urinary tract infection.

Conclusions

Patients reported higher levels of infection and antibiotic use than expected. Patients should be well counselled about symptoms and complications to minimise antibiotic use. Further work is planned to establish whether prophylactic antibiotics will reduce symptomatic infections, antibiotic use and healthcare interactions post-procedure.

Bladder leiomyoma masquerading as a ureterocele

We present a unique case of bladder leiomyoma that was mistakenly diagnosed as a ureterocele. The delay in diagnosis meant ongoing significant voiding lower urinary tract symptoms, which could have been avoided. This was eventually successfully treated by transurethral resection. Leiomyoma is the most common benign bladder mass and should be considered in the differential diagnosis when a smooth mass with normal overlying mucosa is seen on cystoscopy or a homogeneous, low density bladder mass is seen on cross-sectional imaging. Despite the benign nature of the lesion, leiomyoma can convey significant morbidity to the patient.

British Association of Urological Surgeons (BAUS) consensus document: management of bladder and ureteric injury

Injuries to the bladder and ureter are uncommon but usually require prompt urological management. Due to their infrequent nature, Urologists maybe unfamiliar with managing these acute problems and may not work in specialist centres with readily available expertise in open and abdominal surgery. We aim to provide advice in the form of a consensus statement led by the Female, Neurological and Urodynamic Urology (FNUU) Section of the British Association of Urological Surgeons (BAUS), in consultation with BAUS members and consultants working in units throughout the UK, to create a comprehensive management pathway and a series of statements to aid clinicians.

British Association of Urological Surgeons (BAUS) and Nurses (BAUN) consensus document: management of the complications of long-term indwelling catheters

OBJECTIVE

To look at best evidence and expert opinion to provide advice in the form of a consensus statement lead by Female, Neurological and Urodynamic Urology (FNUU) section of the British Association of Urological Surgeons (BAUS) in conjunction with the British Association of Urological Nurses (BAUN).

METHODS

Initially a literature search was performed with incorporation of aspects of the existing guidance and further informed by UK best practice by core members of the group. The document then underwent reviews by the FNUU Executive Committee members, the BAUN executive committee, a separate experienced urologist and presented at the BAUS annual meeting 2020 to ensure wider feedback was incorporated in the document.

RESULTS

Complications of long-term indwelling catheters include catheter-associated urinary tract infections (CAUTI), purple urine bag syndrome, catheter blockages, bladder spasms (causing pain and urinary leakage), loss of bladder capacity, urethral erosion ("catheter hypospadias")/dilatation of bladder outlet and chronic inflammation (metaplasia and cancer risk).

CONCLUSIONS

We have provided a list of recommendations and a troubleshooting table to help with the management of the complications of long term catheters.

British Association of Urological Surgeons (BAUS) consensus document: Management of female voiding dysfunction

OBJECTIVES

To report the British Association of Urological Surgeon's (BAUS) guidance on the assessment and management of female voiding dysfunction.

METHODS

A contemporary literature search was conducted to identify the evidence base. The BAUS Section of Female, Neurological and Urodynamic Urology (FNUU) Executive Committee formed a guideline development group to draw up and review the recommendations. Where there was no supporting evidence, expert opinion of the BAUS FNUU executive committee, FNUU Section and BAUS members, including urology consultants working in units throughout the UK, was used.

RESULTS

Female patients with voiding dysfunction can present with mixed urinary symptoms or urinary retention in both elective and emergency settings. Voiding dysfunction is caused by a wide range of conditions which can be categorized into bladder outlet obstruction (attributable to functional or anatomical causes) or detrusor underactivity. Guidance on the assessment, investigation and treatment of women with voiding dysfunction and urinary retention, in the absence of a known underlying neurological condition, is provided.

CONCLUSION

Wa have produced a BAUS approved consensus on the management pathway for female voiding dysfunction with the aim to optimize assessment and treatment pathways for patients.

The meaning of words - closing the gap in understanding between doctors and patients in 21st century consent

'When I use a word' Humpty Dumpty said, in a rather scornful tone, 'it means just what I choose it to mean, neither more nor less'. 'The question is' said Alice 'whether you can make words mean so many different things'. Through the Looking-Glass, Lewis Carroll, 1872.

Micro-organisms attached to the lumens and balloons of indwelling urinary catheters and correlation with symptoms, antibiotic use and catheter specimen of urine results

To determine micro-organisms attached to removed urethral catheters and relate this to patient-specific information. Indwelling urethral catheters were collected from patients at a UK teaching hospital. The balloon and lumen were sonicated, and micro-organisms were enumerated. Catheter specimen urine results were retrospectively reviewed. Escherichia coli and Enterococcus faecalis were the most common isolates from 61 catheters. 19.7% of patients received antibiotics and 25 % of those had a multi-drug-resistant (MDR) organism in the lumen. Only 2.04% of catheters from patients not receiving antibiotics had a MDR organism. All lumens were colonized irrespective of antibiotic use. Symptom presentation did not correlate with numbers of colonizing organisms or species. Despite heavy colonization, only 8/61 patients were symptomatic. Indwelling urinary catheters in place for ≥10 days were universally colonized and there was no correlation with symptom presentation. Symptom presentation remains the most important factor for defining catheter-associated urinary tract infection.

A tolerability and patient acceptability pilot study of a novel antimicrobial urinary catheter for long-term use

AIMS

We have developed a novel antimicrobial urinary catheter (AUC) impregnated with rifampicin, triclosan, and sparfloxacin and demonstrated that it has long-term (∼84 days) protection against bacterial colonization in vitro. This study aimed to assess the safety and patient acceptability of this device in long-term catheter users.

METHODS

Adults who use long term (>28 days) indwelling urinary catheters with capacity to consent were invited to receive the AUC at their next catheter change. The primary outcome measure was adverse events (AE) attributable to antimicrobial impregnation of the catheter. Secondary outcome measures included severity of related AEs, patient acceptability, early removal of the trial catheter, and degree of microbial colonization of trial catheters. Except for the last, outcomes were assessed by telephone interviews. Original and trial catheters were collected, and the lumens and balloons were separated and analyzed for microbiological colonization.

RESULTS

Thirty participants were recruited. Eighty four AEs were reported, and only one was rated as "probably" related to antimicrobial impregnation. The AE was mild and resolved within 48 h. A total of 82.14% of participants rated the catheter as no different or better than their usual catheter. Two participants chose to remove the AUC early due to it feeling shorter. There were significantly fewer bacterial isolates attached to the balloons of trial catheters compared to the matched original catheters.

CONCLUSIONS

The AUC has an advantageous safety profile and was acceptable to the majority of participants. Information gained from this trial will support a larger randomized controlled study of efficacy.

Isolated Red Patches Seen During Endoscopic Surveillance of Bladder Cancer: Incidence of Malignancy and When Should We Biopsy?

OBJECTIVE

To establish whether the regular biopsy of red patches (RPs) seen during endoscopic surveillance for bladder cancer is worthwhile and determine a suitable time frame for repeat biopsy of prior histologically benign persistent RPs in patients on endoscopic surveillance for bladder cancer.

PATIENTS AND METHODS

Four thousand eight hundred five flexible cystoscopy (FC) reports over a 12-month period were retrospectively reviewed at a United Kingdom tertiary teaching hospital and those undergoing cystoscopic surveillance for bladder cancer and found to have solitary RPs at FC were included in the study. A proportion of these cases had biopsies taken for histopathologic analysis.

RESULTS

Two hundred forty-one FC performed on 183 patients on endoscopic surveillance for bladder cancer had RPs and 120 (49.8%) of them had previous intravesical Bacillus Calmette-Guerin therapy. Eighty-five patients (35.3%) underwent biopsy of the RP. Malignancy was found in 20 biopsies (23.5%), of which, 11 out of 20 (55%) were carcinoma in-situ. Sixteen of these recurrences were biopsied previously, of which 11 (68.8%) were benign at last biopsy, 6 of which were in the last 12 months. The remaining four recurrences had no previous biopsy. No cases of malignancy were identified in patients with low-risk bladder cancer.

CONCLUSION

We recommend the biopsy of all RPs found during endoscopic surveillance of patients with intermediate-/high-risk bladder cancer due to the significant incidence of malignant recurrence identified, particularly if no biopsy has been performed within the previous 12 months. This is independent of previous biopsy histology.

Cytoplasmic PML promotes TGF-β-associated epithelial-mesenchymal transition and invasion in prostate cancer

Epithelial-mesenchymal transition (EMT) is a key event that is involved in the invasion and dissemination of cancer cells. Although typically considered as having tumour-suppressive properties, transforming growth factor (TGF)-β signalling is altered during cancer and has been associated with the invasion of cancer cells and metastasis. In this study, we report a previously unknown role for the cytoplasmic promyelocytic leukaemia (cPML) tumour suppressor in TGF-β signalling-induced regulation of prostate cancer-associated EMT and invasion. We demonstrate that cPML promotes a mesenchymal phenotype and increases the invasiveness of prostate cancer cells. This event is associated with activation of TGF-β canonical signalling pathway through the induction of Sma and Mad related family 2 and 3 (SMAD2 and SMAD3) phosphorylation. Furthermore, the cytoplasmic localization of promyelocytic leukaemia (PML) is mediated by its nuclear export in a chromosomal maintenance 1 (CRM1)-dependent manner. This was clinically tested in prostate cancer tissue and shown that cytoplasmic PML and CRM1 co-expression correlates with reduced disease-specific survival. In summary, we provide evidence of dysfunctional TGF-β signalling occurring at an early stage in prostate cancer. We show that this disease pathway is mediated by cPML and CRM1 and results in a more aggressive cancer cell phenotype. We propose that the targeting of this pathway could be therapeutically exploited for clinical benefit.

Biomaterial modification of urinary catheters with antimicrobials to give long-term broadspectrum antibiofilm activity

Catheter-associated urinary tract infection (CAUTI) is the commonest hospital-acquired infection, accounting for over 100,000 hospital admissions within the USA annually. Biomaterials and processes intended to reduce the risk of bacterial colonization of the catheters for long-term users have not been successful, mainly because of the need for long duration of activity in flow conditions. Here we report the results of impregnation of urinary catheters with a combination of rifampicin, sparfloxacin and triclosan. In flow experiments, the antimicrobial catheters were able to prevent colonization by common uropathogens Proteus mirabilis, Staphylococcus aureus and Escherichia coli for 7 to 12weeks in vitro compared with 1-3days for other, commercially available antimicrobial catheters currently used clinically. Resistance development was minimized by careful choice of antimicrobial combinations. Drug release profiles and distribution in the polymer, and surface analysis were also carried out and the process had no deleterious effect on the mechanical performance of the catheter or its balloon. The antimicrobial catheter therefore offers for the first time a means of reducing infection and its complications in long-term urinary catheter users.

Contemporary Management of recurrent UTI in adult females

The management of recurrent UTI is subject to significant variation and patients may fall under the care of a variety of specialties. We review the pathogenesis, investigation and management of this group of patients. Accurate diagnosis of UTI is the cornerstone of successful management, and careful interpretation of MSU results is needed. Although prophylactic antibiotic regimes are often successful, the emergence of antibiotic resistance mandates the cautious use of antibiotics and consideration of other initial therapies where possible.

The low contact stress patellofemoral replacement

The low contact stress patellofemoral replacement consists of a trochlear component and a modular patellar component which has a metal-backed mobile polyethylene bearing. We present the early results of the use of this prosthesis for established isolated patellofemoral arthritis in 51 consecutive patellofemoral replacements in 35 patients. The mean follow-up was 25 months (5 to 60). The estimated survival rate at three years was 63% (95% confidence interval 47 to 80) with revision as the endpoint and 46% (95% confidence interval 30 to 63) with revision and ongoing moderate or severe pain as the endpoint.

The early results of the use of the low contact stress patellofemoral replacement are disappointing with a high rate of revision. We cannot therefore recommend its use.

Gangrenous cystitis in a 42-year-old male

Gangrenous cystitis is now an extremely rare condition since the widespread use of antibiotics. The authors report a case of gangrenous cystitis in a previously fit and normal 42-year-old male who presented in acute urinary retention. He underwent a partial cystectomy during an exploratory laparotomy for clinical deterioration and peritonitis. Diagnosis of this rare disease is challenged by its low incidence and lack of characteristic pathognomic features, resulting in delayed diagnosis and increased morbidity and mortality. The authors review the literature to date on the aetiology, presentation, diagnosis and management of gangrenous cystitis and emphasise the importance of early and aggressive surgical management.

Coil embolization of posttraumatic pseudoaneurysm of the ophthalmic artery causing subarachnoid hemorrhage

✓The authors report a unique case of subarachnoid hemorrhage caused by a traumatic pseudoaneurysm of the ophthalmic artery, which was successfully treated with coil embolization. Clinical and imaging features, as well as the relevant literature, are described.

Percutaneous radiofrequency ablation of renal tumours: Case series of 11 tumours and review of published work

Detection of renal cell carcinoma (RCC) is increasing with the greater use of cross-sectional imaging and up to two-thirds of RCCs are discovered incidentally in asymptomatic patients. The traditional option of nephrectomy or partial nephrectomy may not always be appropriate. A minimally invasive treatment alternative is radiofrequency ablation (RFA). We retrospectively reviewed the RFA cases for renal tumours at our institution between January 2004 and June 2006. Thirteen RFA treatment sessions were conducted for 11 neoplasms in 11 patients. Mean patient age was 74.4 years (61-88 years). Imaging was carried out after ablation with a mean follow up of 8.0 months (2-26 months). No residual tumour was observed after the first RFA treatment in 82% of patients (nine of 11). Two patients required a second RFA treatment for residual (one) or recurrent tumour (one). RFA is emerging as a useful technique for treatment of small renal tumour. A number of short-term studies reflect this, however, long-term findings are still lacking.

Primary treatment of an indirect carotid cavernous fistula by injection of N-butyl cyanoacrylate in the dural wall of the cavernous sinus

BACKGROUND

Carotid cavernous fistulae are abnormal communications between the carotid artery system and the cavernous sinus. Endovascular treatment is the treatment of choice, but because of their heterogeneous etiology and anatomy, an appropriate treatment plan must be tailored for each patient.

CASE DESCRIPTION

A 77-year-old diabetic woman presented with rapid onset of right eye pain, conjunctivitis, and chemosis. Angiography revealed an indirect CCF located in the posterior wall of the right cavernous sinus. N-Butyl cyanoacrylate was injected directly into the fistula site in the dural wall via a microcatheter, resulting in a cure.

CONCLUSION

We describe an unconventional treatment of an indirect CCF from an IPS approach. One type D(2) CCF was treated successfully using only N-butyl cyanoacrylate injected directly at the fistula site. This was achieved by microcatheterization of the fistula in the posterior wall of the right cavernous sinus.

SIV DNA vaccine co-administered with IL-12 expression plasmid enhances CD8 SIV cellular immune responses in cynomolgus macaques

Current evidence suggests that a strong induced CD8 human immunodeficiency virus type 1 (HIV-1)-specific cell mediated immune response may be an important aspect of an HIV vaccine. The response rates and the magnitude of the CTL responses induced by current DNA vaccines in humans need to be improved and cellular immune responses to DNA vaccines can be enhanced in mice by co-delivering DNA plasmids expressing immune modulators. Two reported to work well in the mouse systems are interleukin (IL)-12 and CD40L. We sought to compare these molecular adjuvants in a primate model system. The cDNA for macaque IL-12 and CD40L were cloned into DNA vectors. Groups of cynomolgus macaques were immunized with 2 mg of plasmid expressing SIVgag alone or in combination with either IL-12 or CD40L. CD40L did not appear to enhance the cellular immune response to SIVgag antigen. However, more robust results were observed in animals co-injected with the IL-12 molecular adjuvant. The IL-12 expanded antigen-specific IFN-gamma positive effector cells as well as granzyme B production. The vaccine immune responses contained both a CD8 component as well a CD4 component. The adjuvanted DNA vaccines illustrate that IL-12 enhances a CD8 vaccine immune response, however, different cellular profiles.

Neuroendovascular Interventions for Intracranial Posterior Circulation Disease via the Transradial Approach: Technical Case Report

OBJECTIVE AND IMPORTANCE:

To describe our experience with the transradial approach for posterior circulation neurointerventional procedures. To the best of our knowledge, this approach has not been described previously for intracranial neuroendovascular procedures.

CLINICAL PRESENTATION:

The clinical and imaging characteristics as well as periprocedural outcomes of patients treated for intracranial posterior circulation disease via the transradial approach were analyzed retrospectively.

INTERVENTION:

Between January 1 and October 21, 2003, four patients with posterior circulation disease (aneurysm, n = 1, and atherosclerotic stenosis, n = 3) were treated via the transradial approach because of tortuous brachiocephalic anatomy. Procedural success was 100%, and there were no procedural complications. No technical difficulties were encountered.

CONCLUSION:

The transradial approach is an alternative to the femoral approach for posterior circulation neuroendovascular intervention. This approach has several advantages over other approaches, and the vasculature can be less tortuous than that encountered during the femoral approach. These factors can result in increased device trackability and procedural ease.

Neuroendovascular interventions for intracranial posterior circulation disease via the transradial approach: technical case report

OBJECTIVE AND IMPORTANCE

To describe our experience with the transradial approach for posterior circulation neurointerventional procedures. To the best of our knowledge, this approach has not been described previously for intracranial neuroendovascular procedures.

CLINICAL PRESENTATION

The clinical and imaging characteristics as well as periprocedural outcomes of patients treated for intracranial posterior circulation disease via the transradial approach were analyzed retrospectively.

INTERVENTION

Between January 1 and October 21, 2003, four patients with posterior circulation disease (aneurysm, n = 1, and atherosclerotic stenosis, n = 3) were treated via the transradial approach because of tortuous brachiocephalic anatomy. Procedural success was 100%, and there were no procedural complications. No technical difficulties were encountered.

CONCLUSION

The transradial approach is an alternative to the femoral approach for posterior circulation neuroendovascular intervention. This approach has several advantages over other approaches, and the vasculature can be less tortuous than that encountered during the femoral approach. These factors can result in increased device trackability and procedural ease.

Extended Lateral Transsylvian Approach for Basilar Bifurcation Aneurysms

THE SURGICAL MANAGEMENT of aneurysms of the basilar apex is one of the most challenging areas in neurosurgery. Successful treatment of this subgroup of aneurysms is dependent on the mastery of technical nuances that have been pioneered and advanced over the past 4 decades. Although both the traditional transsylvian and subtemporal approaches have distinct advantages, each is associated with significant limitations. In this article, the senior author shares his insights into a hybrid approach: the extended lateral transsylvian approach. This approach combines the assets of the two traditional approaches while eliminating their liabilities.

Effect of turning regime and seasonal weather conditions on nitrogen and phosphorus losses during aerobic composting of cattle manure

Cattle manure from stock bedded on straw was aerobically composted under ambient conditions, turning with either a tractor-mounted front-end loader or a rear discharge manure spreader. Three composting experiments, each of approximately four months duration, were conducted to investigate the effect of turning regime and seasonal weather conditions on nitrogen and phosphorus losses during aerobic composting of cattle manure. Manure stacks of 12-15 m(3) initial volume were constructed in separate 5 x 5 m concrete compartments. Experiment 1 (January-April 1999) compared manure heaps turned once (T1) or three times (T3) using a front-end loader with an unturned static (S) control manure stack. Experiment 2 (June-September 1999) compared the same treatments as Experiment 1. Experiment 3 (September-December 1999) compared T1 and T3 turning regimes using a front end loader with turning by a rear-discharge spreader (TR1 and TR1T2) for more effective aeration of the manure. Turning took place at 6 weeks for the one turn treatments, and after 2, 6 and 10 weeks for the three turn treatments. Leachate losses were dominated by NH(4)-N during the first three weeks of composting, after which time NH4-N and NO3-N concentrations in leachates were approximately the same, in the range 0-20 mg N l(-1). The concentrations of both NH4-N and NO3-N in leachate were higher after turning. Molybdate-reactive P concentrations in leachate tended not to be significantly influenced by turning regime. Gaseous losses of NH3 and N2O rose quickly during the initial phases of composting, peaking at 152 g N t(-1) d(-1) for the T3 treatment. Mean NH3 emission rate (25-252 g N t(-1) d(-1)) for the first two weeks of Experiment 2 conducted during the period June-September were an order of magnitude greater (1-10 g N t(-1) d(-1)) than Experiment 3, conducted during the colder, wetter autumn period (September-December). Nitrous oxide emission rates ranged between 1-14 g N t(-1) d(-1) and showed little influence of turning regime. Total N and P concentrations in turned (T) and static (S) manure were elevated at the end of all experiments, due to loss of dry matter. Mean total N losses were 30.4% (T1) and 36.8% (T3) and total P losses 28.2% (T1) and 27.4% (T3).

Disabled infectious single cycle-herpes simplex virus (DISC-HSV) as a vector for immunogene therapy of cancer

Disabled infectious single cycle-herpes simplex viruses (DISC-HSV) have been shown to be safe for use in humans and may be considered efficacious as vectors for immunogene therapy in cancer. Preclinical studies show that DISC-HSV is an efficient delivery system for cytokine genes and antigens. DISC-HSV infects a high proportion of cells, resulting in rapid gene expression for at least 72 h. The DISC-HSV-mGM-CSF vector, when inoculated into tumors, induces tumor regression in a high percentage of animals, concomitant with establishing a cytotoxic T-cell response, which is MHC class I restricted and directed against peptides of known tumor antigens. The inherent properties of DISC-HSV makes it a suitable vector for consideration in human immunogene therapy trials.

Two methods of administration of propofol for dental sedation

Propofol was used for intravenous sedation in a group of 19 healthy fit young patients undergoing third molar extractions. We compared two ways of giving the drug, patient-controlled and operator-controlled, in a crossover trial. There were no differences between the two methods. The psychomotor functions returned to normal by 60 min, there was a high incidence of partial or complete amnesia and both methods were acceptable to 18/19 patients. There were only minimal changes in the respiratory function, and oxygen saturation remained normal. The only problem noted was mild pain on injection in 4 patients.

Establishing an ultrasound guided peripherally inserted central catheter (PICC) insertion service

Peripherally inserted central catheters (PICCs) are an increasingly used means of medium to long-term intravenous access. We have established an ultrasound (US) guided PICC insertion service at our institution that has largely replaced blind bedside insertions. One hundred and six PICCs were inserted in the upper arms of 89 patients, over a 6-month period with a 100% success rate. The technique for US guided vein puncture and guidewire insertion is described. Catheter related complications included infection (6 proven cases; 3.1 infections per 1000 catheter days); catheter blockage (7), breakage (8) and unintentional removal (5). Catheter blockage, breakage and partial unintentional removal are potentially remediable complications using guide-wire techniques under fluoroscopic guidance. The management of catheter related infection is discussed. We have encouraged early communication with our clinical colleagues in order to facilitate the management of such complications and minimize unnecessary catheter removal.

Respiratory effects of intravenous midazolam

Thirty-four healthy, young-adult patients receiving intravenous midazolam for third-molar surgery had their respiratory parameters measured by respiratory inductive plethysmography. Tidal volume and minute volume showed significant changes during the initial 5-10 minutes of sedation, the changes being maximal during the first 5 minutes from the completion of injection of midazolam. The measurement of phase angle, an indicator of respiratory asynchrony, showed no significant change from normal, although a few patients showed some asynchrony of breathing, suggesting some amount of respiratory obstruction. A few patients showed a short period of apnoea and a small fall in the oxygen saturation. None of these changes caused any clinical concerns. It is suggested that the absence of stimulation after injection of midazolam, particularly in the initial few minutes, may contribute to the potential onset of respiratory problems.

Nitrous oxide and the rate of gas uptake from an unventilated lung in dogs

We have studied the effect of FIO2 of a nitrous oxide-oxygen mixture on the rate of gas uptake from an unventilated lung. Nine anaesthetized dogs were studied, each breathing four nitrous oxide-oxygen mixtures (FIO2 0.3, 0.5, 0.75 and 1.0) in random order. A double-lumen endobronchial tube separated lung ventilation. Both lungs were given the nitrous oxide-oxygen mixture for an equilibration period. Then the right lung was connected to a spirometer containing the same gas, and gas uptake measured. In every dog, gas uptake was faster with an FIO2 of 0.5 or 0.75 than with an FIO2 of 1.0. When breathing a nitrous oxide-oxygen mixture with FIO2 > 0.3, the rate of gas uptake from the unventilated lung was faster than with 100% oxygen.

Effect of flumazenil on the recovery from intravenous midazolam

Psychomotor recovery characteristics were studied in young, healthy patients undergoing intravenous sedation using midazolam for the extraction of third molars. There were significant changes to Choice Reaction Time and Critical Flicker Fusion Threshold noted half an hour after the administration of midazolam (P < 0.001). The administration of the benzodiazepine antagonist flumazenil significantly improved the Choice Reaction Times, but failed to reverse changes in Critical Flicker Fusion Threshold up to 120 minutes later. However, the use of flumazenil assured that no post-operative changes in oxygen saturation occurred in any of the patients.

A cadaveric study comparing discography, magnetic resonance imaging, histology, and mechanical behavior of the human lumbar disc

The aims of this study were 1) to compare discography and magnetic resonance imaging scanning on cadaver specimens and to correlate these imaging procedures by examining all the discs histologically; and 2) to study the extent to which the amplitude of rotational movement in the neutral and flexed position at a certain level correlates with the morphologic appearance of that disc. Twenty-four human lumbar spines were harvested from cadavers between the ages of 19 and 75 years. Each specimen underwent standard radiography, magnetic resonance imaging scanning, discography, histologic examination, and measurement of axial rotation in a torsion apparatus. For practical reasons, all specimens did not undergo all of the examinations. Not all peripheral anular lesions were detected by discography. Histology showed rim lesions of the anterior anulus in 18% of discs with normal discography. The overall incidence of anterior and posterior anular tears was greater in discs where larger amplitudes of rotation were observed. To which extent the one is a consequence of the other or vice versa is not clear. Magnetic resonance imaging was found to be less specific than discography. However, it must be emphasized that no axial magnetic resonance imaging scans were taken in this study. Discs with significantly decreased amounts of nuclear material (observed at histology) can still produce normal magnetic resonance imaging images. Infolding of the inner layers of the anulus fibrosus (33% anterior, 4% posterior) was a frequently observed feature.

Demonstration of variation in chondrocyte activity in different zones of articular cartilage: an assessment of the value of in-situ hybridization

Several methods have been described for investigating chondrocyte metabolism in vitro. In this study, in-situ hybridization (ISH) using an oligonucleotide probe (i.e. a poly-d(T) probe) to detect total messenger RNA (mRNA) in cartilage explants has been compared with radiosulphate and radioleucine uptake studies in an attempt to assess the value of ISH in investigating chondrocyte metabolism. The relative results of the three parameters indicate qualitative similarities in cells in the intermediate, deep and calcified zones but differences in the superficial zone. The relative levels of mRNA and leucine and sulphate uptake in the midzone areas could be construed as indicating that the bulk of cellular activity was directed towards the synthesis of proteoglycans. A similar relation between the three parameters, but at a lower level, was seen in chondrocytes in the calcified zone demonstrating that these cells are viable and biosynthetic. Both quantitative and qualitative differences between the three methods were observed in the superficial chondrocytes regarding the amount of mRNA compared to sulphate and leucine uptake. The results suggest that ISH can detect differences in the amount of mRNA present in chondrocytes in differing zones of cartilage and, like the radioleucine and radiosulphate studies, particularly emphasizes their functional heterogeneity.

"Thick" cell membranes revealed by immunocytochemical staining: a clue to the diagnosis of mesothelioma

The distinction of malignant mesothelioma from metastatic adenocarcinoma in pleural effusions and biopsies is frequently a diagnostic problem. Immunocytochemical staining of 13 malignant mesotheliomas, eight primary adenocarcinomas of the lung, five metastatic adenocarcinomas of the lung, and 20 primary adenocarcinomas in extrapulmonary sites with a monoclonal antibody to epithelial membrane antigen (EMA) revealed "thick" cell membranes in all cases of mesothelioma. This distinctive pattern of staining was seen in the periphery of cell clusters and circumferentially around individual cells in cytologic preparations, cell blocks, and tissue sections. Intracellular and intercellular acini were also outlined by anti-EMA, and long intraluminal microvillous projections were demonstrated. Weak cytoplasmic staining was only rarely seen in mesothelioma cells. This membranous staining pattern was not observed in adenocarcinomas, which displayed strong and diffuse cytoplasmic staining. The immunocytochemical demonstration of thick and spiky membranes circumferentially disposed around individual cells corresponds to aberrant microvilli, a diagnostic clue in the recognition of malignant mesothelioma.