Bioluminescence assay for the highly sensitive detection of botulinum neurotoxin A activity.

This article describes a novel bioluminescence assay for detecting the proteolytic activity of Botulinum NeuroToxins (BoNT) in complex matrices. The assay is capable of detecting traces of BoNT in blood samples as well as in food drinks. The assay was responsive to BoNT/A subtypes 1 to 5, and serotype E3 in buffered solutions. It was responsive to filtered Clostridium botulinum supernatants and BoNT/A1 in complex with neurotoxin associated proteins in bouillon and milk (3.8% fat) down to 400 fM after 4 h RT incubation and in bouillon at concentrations down to 120 fM after 21 h RT incubation. In combination with an immunocapture/enrichment step it could detect BoNT/A1 in citrated plasma at concentrations down to 30 fM (1.2 mouse LD50 per mL). The simplicity of the assay, combined with a demonstrated ability to lyophilize the reagents, demonstrates its usefulness for detection of BoNT in non-specialised analytical laboratories.

The measurement of patellar height: a review of the methods of imaging.

Many radiographic techniques have been described for measuring patellar height. They can be divided into two groups: those that relate the position of the patella to the femur (direct) and those that relate it to the tibia (indirect). This article looks at the methods that have been described, the logic behind their conception and the critical analyses that have been performed to test them.

Penetrating injury from laminated glass--a trap for the unwary.

Although the incidence of glass injury following road traffic accidents has been decreasing over the past five decades, the location and source of glass bodies from accidents involving vehicles can prove difficult for the radiologist and surgeon and in medico-legal disputes. This case illustrates the issues with regard to penetrating injuries from different types of glass used in the automotive industry. Shatterproof glass windscreens with a laminated coating have been developed to prevent fragmentation and dispersal. This has led to a significant reduction in glass-related injury. Although laminated glass fitted in front windscreens and in some side windows is designed not to shatter, fragmentation can indeed take place in cases of high impact, resulting in penetrating injury that can be difficult to detect and can lead to injury and morbidity. The attending clinician should therefore consider penetrating injuries in the clinical and radiological assessment of individuals who present after motor vehicle accidents and be aware that laminated glass, although considered to be "safe", can indeed be responsible for penetrating injury. We present a unique case report to illustrate this important point, which may encourage debate in the medical world and motor manufacturing industry.

Extranodal lymphomas presenting as soft tissue sarcomas to a sarcoma service over a two-year period.

Non-Hodgkin's lymphoma usually presents with lymphadenopathy at multiple sites but can also involve any part of the musculoskeletal system. Occasionally the presentation is with a soft tissue mass. The presentation of large, superficial lymphomatous masses is similar both clinically and radiologically to that of soft tissue sarcomas. The six cases of lymphoma presenting to the Exeter Sarcoma Service as suspected soft tissue sarcomas, over a two-year period (2002-2004), are presented. We describe the clinical and imaging characteristics of these tumours and their subsequent management. Our cases showed variability in presentation. Only one of the six cases presented with pain and one with tenderness. Four of the cases had no lymphadenopathy and the other two had lymphadenopathy restricted to one nodal basin. Overlying soft tissue swelling occurred in four cases and in distal limb swelling beyond the mass in one case. Radiologically, lymphomas are known to be likely to exhibit confluent lymphadenopathy that is rare in patients with soft tissue sarcoma. Confluent lymphadenopathy was demonstrated in only one case of this series of patients. It is thought that lymphomas infiltrate across anatomical fascial planes more readily than sarcomas and in four of our six cases this feature was present. Clinical history, examination and MRI are insufficient to differentiate between soft tissue sarcoma and lymphoma and the importance of obtaining a pathological diagnosis prior to surgery is clear. It is crucial to differentiate lymphoma from sarcoma in order to avoid unnecessary excisional procedures in lymphoma patients.

Neurotized Free Muscle Flaps can Produce MRI Changes Mimicking Tumour Recurrence.

Soft tissue sarcomas are investigated by magnetic resonance imaging (MRI) both for initial staging and follow-up. We describe the presence of increased signal on T2-weighted images caused by a neurotized muscle flap following reconstructive surgery. This raised concern about possible sarcoma recurrence that was not clinically evident. On post-operative imaging of sarcomas the presence of recurrent tumour is indicated by a mass and high signal intensity on T2-weighted images. However, high signal changes in skeletal muscle on T2-weighted images are not specific. In this case, the free functioning muscle transfer with neurotization of the flap mimicked recurrence on MR scan. High signal intensity on T2-weighted images in muscle is an indication of either a physiological change or a pathological condition and must be taken in context of the clinical picture.

Ultrasound-guided aspiration of posterior cruciate ligament ganglion cysts.

Intra-articular ganglion cysts of the knee joint are rare. Percutaneous aspiration of ganglion cysts of the knee, which has both diagnostic and therapeutic value, has been described, but usually under guidance by computed tomography (CT). We describe ultrasound-guided aspiration of posterior cruciate ligament cysts in two patients.

Asthma after childhood pneumonia: six year follow up study.

OBJECTIVE: To establish the long term cumulative prevalence of asthma in children admitted to hospital with pneumonia and to examine the hypothesis that some children admitted to hospital with pneumonia may be presenting with undiagnosed asthma. DESIGN: Prospective study of a cohort of children previously admitted to hospital with pneumonia, followed up by postal questionnaires to their general practitioners and the children or their parents. SETTING: General practices in southwest England. PARTICIPANTS: 78 children admitted to the Royal Devon and Exeter Hospital between 1989 and 1991 with a diagnosis of pneumonia confirmed on independent review of x ray films. MAIN OUTCOME MEASURES: Any diagnosis of asthma, use of any treatment for asthma, and asthma symptom scores. RESULTS: On the basis of a 100% response rate from general practitioners and 86% from patients or parents, the cumulative prevalence of asthma was 45%. A diagnosis of asthma was associated with a family history of asthma (odds ratio 11.23; 95% confidence interval 2.57 to 56.36; P=0.0002). Mean symptom scores were higher for all children with asthma (mean score 2.4; chi(2)=14.88; P=0. 0001) and for children with asthma not being treated (mean 1.4; chi(2)=6.2; P=0.01) than for those without asthma (mean 0.2). CONCLUSIONS: A considerable proportion of children presenting to a district general hospital with pneumonia either already have unrecognised asthma or subsequently develop asthma. The high cumulative prevalence of asthma suggests that careful follow up of such children is worth while. Asthma is undertreated in these children; a structured symptom questionnaire may help to identify and reduce morbidity due to undertreatment.

Pathologic findings at the time of nephrectomy for renal mass.

BACKGROUND: Ultrasound (US) and computed tomography (CT) have improved the diagnosis of solid renal masses. Nevertheless, some patients still undergo exploration for a presumptive diagnosis of renal cell carcinoma (RCC) and are found to have other pathology. We report a contemporary series of non-RCC renal masses (both incidental and symptomatic) among nephrectomies performed for suspected RCC. MATERIALS AND METHODS: All nephrectomies performed by the Urology Service at the Memorial Sloan-Kettering Cancer Center from July of 1989 through July of 1996 for a parenchymal renal mass were reviewed, and patients without a final diagnosis of RCC were identified. Cases were excluded if RCC was not suspected preoperatively. Presentation, preoperative radiographic evaluation, type of operation, and pathologic features were assessed. RESULTS: Of the 636 nephrectomies performed, 108 patients (16.9%) had a diagnosis other than RCC. CONCLUSIONS: Of patients undergoing nephrectomy for renal masses, 16.9% have other pathologic diagnoses. Sixty-six percent of these non-RCC masses are discovered incidentally, and the majority are treated with radical nephrectomy. Preoperative radiographic evaluation reflects both clinical presentation, with IVP used to evaluate symptomatic tumors, and diagnostic uncertainty, with multiple modalities used to evaluate cystic lesions. This information has important implications for preoperative counseling and surgical planning.

Ureteral carcinoma in situ at radical cystectomy: does the margin matter?

PURPOSE: The clinical impact of ureteral carcinoma in situ identified at the time of radical cystectomy for bladder cancer has been poorly studied. We discuss our experience with this clinical problem in the context of published reports. MATERIALS AND METHODS: A total of 31 patients with concomitant ureteral carcinoma in situ was retrospectively identified among 401 consecutive radical cystectomies. End points analyzed included positive urinary cytology, upper tract recurrence of carcinoma and cancer specific survival. RESULTS: Ureteral margins were positive in 21 patients and negative in 10. Among 30 patients in whom it was performed frozen section failed to detect carcinoma in situ in 5 (16.6%) and sequential ureteral resection did not result in a negative margin in 15 (50%). In 3 patients upper tract carcinoma recurred at the anastomosis (1) and renal pelvis/ureter (2) at a median of 51 months (mean 49, range 36 to 59) following cystectomy. Positive cytology and upper tract carcinoma recurrence were not significantly associated with ureteral margin status, clinical or pathological bladder tumor stage or prior bacillus Calmette Guerin treatment. Median followup was 22.9 months (mean 31.8, range 2.0 to 74.2), during which 7 of the 31 patients died of metastatic bladder cancer. CONCLUSIONS: Concomitant ureteral carcinoma in situ is uncommon, and is rarely associated with local morbidity. It appears to confer increased risk for upper tract carcinoma recurrence, irrespective of margin status. In our experience upper tract carcinoma recurrence is heralded by positive cytology and generally appears only with protracted followup. Prognosis appears to be determined by the bladder tumor. Given the lack of morbidity and mortality attributable to concomitant ureteral carcinoma in situ, and the limited ability of frozen section examination to assist in its extirpation, the value of intraoperative identification of concomitant ureteral carcinoma in situ is questionable and expectant management is advised.

Prostate-specific membrane antigen expression in normal and malignant human tissues.

Prostate-specific membrane antigen is a type II membrane protein with folate hydrolase activity produced by prostatic epithelium. The expression of this molecule has also been documented in extraprostatic tissues, including small bowel and brain. In the present study, an extensive immunohistochemical analysis was performed on a panel of well-characterized normal and malignant human tissues to further define the pattern of prostate-specific membrane antigen (PSMA) expression. Detectable PSMA levels were identified in prostatic epithelium, duodenal mucosa, and a subset of proximal renal tubules. A subpopulation of neuroendocrine cells in the colonic crypts also exhibited PSMA immunoreactivity. All other normal tissues, including cerebral cortex and cerebellum, had undetectable levels of PSMA. Thirty-three of 35 primary prostate adenocarcinomas and 7 of 8 lymph node metastases displayed tumor cell PSMA immunostaining. Eight of 18 prostate tumors metastatic to bone expressed PSMA. All of the other nonprostatic primary tumors studied had undetectable PSMA levels. However, intense staining was observed in endothelial cells of capillary vessels in peritumoral and endotumoral areas of certain malignancies, including 8 of 17 renal cell carcinomas, 7 of 13 transitional cell carcinomas, and 3 of 19 colon carcinomas. Extraprostatic PSMA expression appears to be highly restricted. Nevertheless, its diverse anatomical distribution implies a broader functional significance than previously suspected. The decrease in PSMA immunoreactivity noted in advanced prostate cancer suggests that expression of this molecule may be linked to the degree of tumor differentiation. The neoexpression of PSMA in endothelial cells of capillary beds in certain tumors may be related to tumor angiogenesis and suggests a potential mechanism for specific targeting of tumor neovasculature.

Computed tomography of the brain in acute carbon monoxide poisoning.

Of 107 patients admitted to the South Western Hyperbaric Medical Centre with acute carbon monoxide poisoning for hyperbaric oxygen therapy 19 had cerebral imaging performed: 17 patients had CT, one patient had MRI and CT and one patient MRI alone. The role of brain CT is established in determining the prognosis from acute carbon monoxide poisoning. Brain imaging was indicated because of unconsciousness on admission and failure or delayed improvement in neurological status after initiation of hyperbaric oxygen therapy. Of the 18 patients who underwent brain CT, seven were found to have the characteristic changes of bilateral low attenuation areas within the globus pallidus and six had low attenuation changes within cerebral white matter. In two patients there were both globus pallidus and cerebral white matter changes. Out of the total of the 19 patients who were studied, four patients died, 10 recovered fully and five had variable disabilities ranging from short term memory loss to more severe cognitive impairment and physical disability. The role of CT and the practicalities of hyperbaric oxygen therapy for acute carbon monoxide poisoning are discussed in the light of the experience from a regional dedicated medical diving centre.

Prenatal ultrasound diagnosis of fetal candida infection: a complication of a retained intrauterine contraceptive device.

A 32-year-old woman was referred complaining of abdominal pain and bleeding at 18 weeks' gestation. The striking finding on ultrasound examination was of symmetrically enlarged echogenic fetal lungs. In addition, mediastinal compression, increased echogenicity of the kidneys and bowel, an enlarged liver of decreased echogenicity, and hydrops fetalis, as evidenced by ascites and skin edema, were all present. The differential diagnosis included upper respiratory tract obstruction and cystic kidney disease. The presence of fetal hydrops together with the other findings suggested a poor outcome, and on these grounds therapeutic abortion was recommended and performed. Subsequent postmortem findings explained all the ultrasound abnormalities on the basis of extensive fetal candida infection. The presence of a retained intrauterine contraceptive device was considered to be the likely cause and the implications of this, together with the ultrasound abnormalities and differential diagnoses, are discussed.

Heel pad thickness following calcaneal fractures: ultrasound findings.

Ultrasound measurements of heel pad thickness in 21 patients who had suffered unilateral fractures of the calcaneum were taken. Body weight was also recorded. Contrary to previous assertions in the literature, heel pad thinning was not found to occur and in fact a significant increase in heel pad thickness on the affected side was noted.

Gas-containing ganglia of the hip.

Three cases of ganglia related to the hip containing gas are presented. Gas may be shown by conventional radiography, linear tomography or computed tomography. All three cases had advanced degenerative disease of the joint. In degenerative disease, ganglia form through a pathway which allows the transfer of intra-articular gas into the ganglion. It is important to differentiate this phenomenon from overlying bowel gas and other causes of gas within soft tissues. It is the most specific radiological feature of ganglia around the hip.

Congenital displacement of temporal cortex into the central spinal canal.

This is a report of the first recorded observation of displacement of temporal cortex into the central spinal canal in an infant with Arnold Chiari malformation, platybasia, aqueductal atresia, hydrocephalus and meningomyelocele. The combination of an absent right cerebellar hemisphere and malformed fourth ventricular roof provided the anatomical background for this unique event.