Why is there still hepatitis C transmission in Australian prisons? A case report

BACKGROUND

The ability to cure hepatitis C viral infection, with specific reference to the prisoner population and the prison environment, will be challenged, even if opiate replacement therapy is concurrently offered, and even if bleach is available. The missing elements, widely available in the community, are a regulated injecting equipment exchange and tattooing parlours.

CASE PRESENTATION

We report a case of re-infection of hepatitis C in a prisoner treated with a direct-acting antiviral. What makes this case so remarkable is that it was entirely predictable and preventable.

CONCLUSIONS

Hepatitis C infection will continue to test both the strengths and the weaknesses in the relationship between health and corrective services in Australia. Nothing less than full implementation of all harm minimisation modalities will be necessary to eliminate the clinical and public health risks of hepatitis C infection, both in prison and by extension into the general community.

Infections following lawnmower and farm machinery-related injuries in children

AIMS

Because of the paucity of previous data, we report the organisms causing infection in children with injuries from lawnmowers and farm machinery.

METHODS

Retrospective study of children admitted to the Children's Hospital at Westmead for lawnmower and farm machinery-related injuries from 1998 to 2007.

RESULTS

Twenty-four patients were admitted for lawnmower-related injuries. They had a bimodal age distribution, with peaks at 2-4 years and 14 years. Twenty-one (87.5%) were boys. Positive wound cultures were obtained in 16.7% and included Gram-positive and Gram-negative organisms. Eight patients were admitted for farm machinery-related injuries. Two patients (25%) returned positive wound cultures with multiple organisms including bacteria, fungi and mycobacteria and were diagnosed with osteomyelitis caused by Stenotrophomonas maltophilia and Scedosporium prolificans, respectively.

CONCLUSION

The rate of infection in our small series of children with lawnmower and farm machinery-related injuries was comparable to previous reports. We found a wide range of causative organisms, often inherently antibiotic resistant, and we add a case of invasive fungal infection to previous case reports. Because of the wide range of organisms, empirical antibiotic therapy is difficult and our data emphasise the need for cultures to direct ongoing therapy.

Staging by positron emission tomography predicts survival in patients with non-small cell lung cancer

BACKGROUND

Positron emission tomography (PET) scanning is used increasingly to detect and stage lung cancer, but the test performance characteristics and relationship of PET to patient outcomes remain undefined.

OBJECTIVE

To determine the test performance characteristics and relationship of PET scanning stage to patient outcomes relative to the 1997 International System for the Staging of Lung Cancer.

DESIGN

Survival analysis using pathologic staging as the criterion standard for comparison of survival as predicted by staging by PET and CT.

SETTING

University-based hospital.

PATIENTS

All consecutive patients undergoing PET scanning for the evaluation of possible non-small cell lung cancer (NSCLC) during a 5-year period.

MAIN OUTCOME MEASURES

Long-term survival of patients with NSCLC after staging by PET.

RESULTS

One hundred fifty-two thoracic PET scans were obtained for the staging of possible NSCLC during a 5-year period. One hundred twenty-three patients (81%) demonstrated increased (18)F-fluorodeoxyglucose uptake. The overall sensitivity and specificity of PET for detecting malignancy were 95% and 67%, respectively, compared with 100% and 27% for chest CT. PET and CT had similar accuracy for staging the overall extent of disease (91% and 89%, respectively). PET stage correlated highly with survival using either nodal location or overall stage (p = 0.003, p = 0.002), as did pathologic staging (p = 0.0001, p = 0.0001). CT scan results did not accurately predict survival (p = 0.608, p = 0.338).

CONCLUSION

PET scanning is a highly sensitive technologic advance in detecting and staging of thoracic malignancy and may more accurately predict the likelihood of long-term survival in patients with NSCLC than chest CT does.

The role of lateral cephalometric radiography and fluoroscopy in assessing mandibular advancement in sleep-related disorders

Mandibular advancement splints are successful in managing obstructive sleep apnoea (OSA) in selected subjects. For these to be effective, some improvement in the dimensions of the oropharyngeal airway must occur. Twenty subjects with proven obstructive sleep apnoea were examined using lateral cephalometric radiography and a fluoroscopic technique. Cephalograms were analysed, and assessed for both skeletal and soft tissue abnormalities known to be present in OSA subjects. On the basis of these, a prediction was made as to whether the subject's oropharyngeal airway would increase during mandibular protrusion. From the fluoroscopic sequences, the narrowest antero-posterior dimensions of the post-palatal and post-lingual airways were recorded as the mandible moved from the intercuspal position into maximal protrusion. The changes in airway size were noted and these were compared with the predictions made from the static films. In nine subjects, fluoroscopy indicated that the airway opened well during mandibular protrusion, seven did not improve and in four the changes were minimal. Post-palatally the mean airway increase was 2.6 mm, whilst behind the tongue a mean improvement of 3.1 mm was seen. In all but two instances, the cephalometric prediction agreed exactly with the outcome demonstrated by fluoroscopy. All subjects whose airways clearly increased were correctly identified by the cephalogram alone. Cephalometric features associated with a good airway response to protrusion were a reduced lower facial height, low maxillomandibular planes angle and a high hyoid position, accompanied by a normal anteroposterior relationship of the jaws, relatively normal mandibular body length and soft palate area. The more abnormal the skeletal and soft tissue dimensions, the poorer the prognosis. Thus, whilst a single radiograph could indicate whether a positive mandibular response to protrusion could be expected, where doubt existed, a fluoroscopic analysis could provide a useful adjunct to diagnosis.

Comparison and evaluation of retrospective intermodality brain image registration techniques

PURPOSE

The primary objective of this study is to perform a blinded evaluation of a group of retrospective image registration techniques using as a gold standard a prospective, marker-based registration method. To ensure blindedness, all retrospective registrations were performed by participants who had no knowledge of the gold standard results until after their results had been submitted. A secondary goal of the project is to evaluate the importance of correcting geometrical distortion in MR images by comparing the retrospective registration error in the rectified images, i.e., those that have had the distortion correction applied, with that of the same images before rectification.

METHOD

Image volumes of three modalities (CT, MR, and PET) were obtained from patients undergoing neurosurgery at Vanderbilt University Medical Center on whom bone-implanted fiducial markers were mounted. These volumes had all traces of the markers removed and were provided via the Internet to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/ or from PET to MR. These investigators communicated their transformations again via the Internet to Vanderbilt, where the accuracy of each registration was evaluated. In this evaluation, the accuracy is measured at multiple volumes of interest (VOIs), i.e., areas in the brain that would commonly be areas of neurological interest. A VOI is defined in the MR image and its centroid c is determined. Then, the prospective registration is used to obtain the corresponding point c' in CT or PET. To this point, the retrospective registration is then applied, producing c" in MR. Statistics are gathered on the target registration error (TRE), which is the distance between the original point c and its corresponding point c".

RESULTS

This article presents statistics on the TRE calculated for each registration technique in this study and provides a brief description of each technique and an estimate of both preparation and execution time needed to perform the registration.

CONCLUSION

Our results indicate that retrospective techniques have the potential to produce satisfactory results much of the time, but that visual inspection is necessary to guard against large errors.

Lag phase quantification for solid gastric emptying studies

This study compared the different calculation methods of the solid gastric emptying lag phase and evaluated the effect of the temporal sampling interval on the calculated value using the modified power exponential (MPE) method.

METHODS

Twenty normal control subjects and 42 patients had anterior and posterior image acquisition on a multihead gamma camera, one frame per minute x 90. ROIs were selected for the stomach, gastric antrum and small bowel. Time-activity curves (TACs) were generated for anterior, posterior and geometric mean data. The lag phase was calculated using various methods such as transition point, starting index, first appearance of bowel activity (FABA), MPE and antral peak filling time. To determine the importance of the temporal sampling rate on the calculation of the lag phase by the MPE, intervals between 1 and 20 min were analyzed.

RESULTS

The transition point, starting index and FABA correlated extremely high (r = > or = 0.92) in normal control subjects and patients. Normal lag phase values were mean 22-24 +/- 10 min for transition point, starting index and FABA compared with 47 +/- 18 min for the MPE method (p < 0.0001). The MPE correlated poorly with the other method (r = 0.74). Antral peak filling time correlated poorly (r = 0.47) with transition point, starting index and FABA, but somewhat better with the MPE (r = 0.70). Comparing 15-min versus 1-min sampling intervals using the MPE, 35% of subjects had values that differed by > or = 7.5 min and 10% had values differing by > or = 15 min.

CONCLUSION

The lag phase calculated by the MPE correlated poorly with other methods, and its accuracy was limited by the rate of the temporal sampling. The transition point, starting index and FABA all highly correlated with each other; the latter is a particularly reliable physiological indicator and is easily quantified using a small-bowel TAC.

A method of studying adaptive changes of the oropharynx to variation in mandibular position in patients with obstructive sleep apnoea

The aim of this study was to develop a method of studying the effects of mandibular advancement on oropharyngeal airway dimensions in the sagittal plane in conscious, supine patients. Six white, dentate, male patients with proven obstructive sleep apnoea had sagittal fluoroscopic recordings taken in the resting supine position. Images were recorded at four frames per second as the mandible was advanced with the teeth in contact to maximum protrusion and then opened. Software in the fluoroscopic imaging system permitted measurement of the change in mandibular position together with oropharyngeal airway dimensions expressed as the narrowest dimension observable in the post-palatal and post-lingual sites. Plotting of airway dimensions during mandibular advancement enabled estimation of the degree of protrusion associated with maximal airway benefits. Progressive mandibular advancement produced variable adaptive changes in the post-palatal and post-lingual regions of the oropharynx. The amount of airway opening appeared to be related to the horizontal and vertical relationships of the face and to the dimensions of the soft palate. The changes in post-palatal and post-lingual airway dimensions were not always identical, despite the observation that both tongue and soft palate were seen to move in unison, with close contact being maintained between the two structures. Jaw opening resulted in synchronous posterior movement of both tongue and soft palate, with consequent narrowing of oropharyngeal airspace. Fluoroscopy is a simple method of assessing upper airway changes with mandibular advancement in the conscious patient. The technique should facilitate the selection of subjects for whom mandibular advancement would seem advantageous. The nature of the adaptive response is dependent on individual structural variation. It is suggested that, where artificial mandibular advancement with dental devices is considered beneficial, jaw opening should be kept to a minimum.

The importance of a multidisciplinary approach to the assessment of patients with obstructive sleep apnoea

Obstructive sleep apnoea may present with a wide range of symptoms resulting in a variety of referral pathways. A multidisciplinary approach to examination and diagnosis helps to determine the most appropriate treatment plan for each individual. The subject is seen by each member of the team, appropriate investigations undertaken and a further meeting arranged at which all opinions are discussed. A reasoned treatment regime is produced, taking into consideration the patient's wishes and overall medical condition. This paper describes the team approach currently employed in the Department of Thoracic Medicine at The Prince Charles Hospital, Brisbane, Australia. The thoracic physician and ENT surgeon work in close collaboration with their dental colleagues: an orthodontist, prosthodontist and a maxillofacial surgeon. An outline of the examination and investigations made by each is described and the multidisciplinary approach is illustrated by a description of the management of five subjects with suspected obstructive sleep apnoea.

The importance of a multidisciplinary approach to the assessment of patients with obstructive sleep apnoea

Obstructive sleep apnoea may present with a wide range of symptoms resulting in a variety of referral pathways. A multidisciplinary approach to examination and diagnosis helps to determine the most appropriate treatment plan for each individual. The subject is seen by each member of the team, appropriate investigations undertaken and a further meeting arranged at which all opinions are discussed. A reasoned treatment regime is produced, taking into consideration the patient's wishes and overall medical condition. This paper describes the team approach currently employed in the Department of Thoracic Medicine at The Prince Charles Hospital, Brisbane, Australia. The thoracic physician and ENT surgeon work in close collaboration with their dental colleagues: an orthodontist, prosthodontist and a maxillofacial surgeon. An outline of the examination and investigations made by each is described and the multidisciplinary approach is illustrated by a description of the management of five subjects with suspected obstructive sleep apnoea.

The diagnosis of acute pyelonephritis in the piglet using single photon emission computerized tomography dimercaptosuccinic acid scintigraphy: a pathological correlation

Single photon emission computerized tomography (SPECT) scintigraphy has proved to be an extremely sensitive renal imaging modality in children with genitourinary pathology, including pyelonephritis, particularly when compared to 2-dimensional planar imaging. This study was undertaken to corroborate SPECT dimercaptosuccinic acid (DMSA) scintigraphic findings with specific histopathology in acute pyelonephritis. Unilateral vesicoureteral reflux was produced in 19 Yorkshire piglets 3 to 4 weeks old. The bladders of 12 animals were inoculated with Escherichia coli 2 weeks later, after baseline SPECT DMSA scans had been obtained. The animals were then re-imaged at 3 (4), 7 (4) or 14 (4) days after infection and sacrificed for histological evaluation. Seven purposefully uninfected piglets with unilateral reflux served as controls and were followed for up to 6 weeks before imaging and sacrifice. SPECT proved to be 97% sensitive and 93% specific in providing the diagnosis of acute pyelonephritis. The SPECT findings were manifest by a spectrum of abnormal findings (mottling, striations, inner cortical scalloping and focal cortical defects), which correlated precisely with the extent and severity of cortical involvement in the acute pyelonephritic process. We propose a new classification scheme for SPECT DMSA renal scintigraphic imaging, and believe that this modality is exquisitely sensitive in providing the diagnosis as well as in evaluating the extent of renal parenchymal involvement when acute pyelonephritis is induced in the animal model.

Improved detection of small cavernous hemangiomas of the liver with high-resolution three-headed SPECT

The purpose of this study was to review our experience with 99mTc-red blood cell scintigraphy for diagnosis of cavernous hemangiomas of the liver using a new three-headed, high-resolution dedicated SPECT system. Of 19 patients referred with a total of 38 lesions seen on CT, US, or MRI, 14 patients had 24 lesions that were hemangioma-positive with SPECT (all true-positives). Six of these 14 patients also had 9 hemangioma-negative lesions; all were less than or equal to 1.3 cm in size and false-negative. The remaining five patients had hemangioma-negative lesions only (1 false-negative, 4 true-negatives). Two hemangiomas were seen by SPECT that were not detected by CT, US, or MR. The sensitivity for hemangiomas greater than or equal to 1.4 cm. was 100% (20/20). The sensitivity was 33% for lesions 0.9-1.3 cm, and 20% for lesions less than or equal to 0.8 cm. The smallest hemangioma detected was 0.5 cm. These results show a definite improvement in sensitivity with high-resolution triple-headed SPECT over previously reported results using single-headed SPECT. High-resolution SPECT has improved our ability to detect small cavernous hemangiomas of the liver.

High resolution single photon emission computerized tomography (SPECT) 99mtechnetium-dimercapto-succinic acid renal imaging: a state of the art technique

The 99mtechnetium-dimercapto-succinic acid renal scan has become the gold standard for evaluating renal parenchymal pathology. The traditional pinhole technique provides 2-dimensional imaging. Recent application of high resolution single photon emission computerized tomography (SPECT) has provided the means to obtain even greater cortical detail. With 360-degree imaging and computer reconstruction, SPECT provides coronal, sagittal and transaxial imaging. We prospectively compared the SPECT and pinhole techniques in 33 patients (65 renal units) ranging in age from 2.5 months to 18 years. Both scans were obtained in all patients. All scans were reviewed by an independent interpreter. Using SPECT imaging, diagnostic information was enhanced in 46 of the 65 kidneys (71%). Of the 24 kidneys that appeared "normal" by pinhole imaging 15 (63%) had defects on SPECT imaging. High resolution SPECT imaging improves the ability to identify cortical defects and visualize asymmetry of cortical thickness compared to standard pinhole imaging.