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Biomedical subjects

J Clinton

Publications and source records attributed to J Clinton.

15 recordsLinked to original sources

Prion protein immunocytochemistry helps to establish the true incidence of prion diseases.

Creutzfeldt-Jakob disease (CJD) and Gerstmann-Strüssler-Scheinker disease (GSSD) are transmissible spongiform encephalopathies or prion diseases affecting man. It has been reported that prion diseases may occur without the histological hallmarks of spongiform encephalopathies: vacuolation of the cerebral grey matter, neuronal loss and astrocytosis. These cases without characteristic neuropathology may go undiagnosed and consequently the true incidence of transmissible dementias is likely to have been under-estimated. Immunocytochemistry using antibodies to prion protein gives positive staining of these cases, albeit the pattern of immunostaining differs from that seen in typical forms. Accumulation of prion protein is a molecular hallmark of prion diseases, and thus a reproducible, speedy and cost-efficient immunocytochemical screening of unusual dementias may help to establish the true incidence of prion diseases.

Adult

Quantification of beta A4 protein deposition in the medial temporal lobe: a comparison of Alzheimer's disease and senile dementia of the Lewy body type.

The distribution of beta-amyloid protein (beta A4) was examined in the medial temporal lobes from cases of Alzheimer's disease (AD) (n = 13), senile dementia of Lewy body type (SDLT) (n = 12) and age matched controls (n = 9). Using a previously described image analysis technique the extent of beta A4 pathology was determined in ten distinct anatomical sites within the medial temporal lobe. AD and SDLT cases contained very similar amounts of beta A4 in the areas sampled and both contained significantly more beta A4 than the age matched controls, particularly in the dentate and parahippocampal gyri. The similarity of the beta A4 load in the two conditions is in contrast to reported differences in the number of neurofibrillary tangles which can be observed. It is suggested that AD and SDLT represent a spectrum of pathology which centres around the aberrant processing of the beta A4 precursor protein.

Aged

Quantifying the pattern of beta/A4 amyloid protein distribution in Alzheimer's disease by image analysis.

We have undertaken a study of the distribution of the beta/A4 amyloid deposited in the cerebral cortex in Alzheimer's disease. Previous studies which have examined the differential distribution of amyloid in the cortex in order to determine the laminar pattern of cortical pathology have not proved to be conclusive. We have developed an alternative method for the solution of this problem. It involves the immunostaining of sections followed by computer-enhanced image analysis. A mathematical model is then used to describe both the amount and the pattern of amyloid across the cortex. This method is both accurate and reliable and also removes many of the problems concerning inter and intra-rater variability in measurement. This method will provide the basis for further quantitative studies on the differential distribution of amyloid in Alzheimer's disease and other cases of dementia where cerebral amyloidosis occurs.

Alzheimer Disease

Post-traumatic Alzheimer's disease: preponderance of a single plaque type.

The cause of Alzheimer's disease is unknown. Several factors have been proposed including head trauma. At present, the link between head injury and a subsequent neurodegenerative process is largely circumstantial, except in the case of dementia pugilistica (punch drunk syndrome) found in boxers. Recent studies have shown that the brains of boxers with this syndrome contain large numbers of 'diffuse' beta-protein immunoreactive plaques. We supposed that this plaque type might be associated with trauma induced Alzheimer-like degeneration. In order to test this hypothesis we have re-investigated a previously reported case of post-traumatic premature Alzheimer's disease. Immunocytochemistry using antibodies to amyloid beta-protein revealed large numbers of 'diffuse' non-Congophilic plaques with little or no neuritic component. A similar preponderance of this plaque type is present in the brains of boxers with dementia pugilistica. Our observations support the idea of a trauma induced Alzheimer-like degenerative process and indicate that such a condition is associated with a marked preponderance of 'diffuse' plaques.

Adult

A comparison of open peritoneal lavage with modified closed peritoneal lavage in blunt abdominal trauma.

A randomized prospective study compared open peritoneal lavage using a peritoneal dialysis catheter with modified closed lavage using either the Lazarus-Nelson or Cook lavage catheter. The time required to perform the lavage, technical difficulties, complications, and accuracy were assessed in 63 adult victims of blunt abdominal trauma. The average time to perform lavage was 21.1 minutes for open lavage, 14.7 minutes for Lazarus-Nelson closed lavage, and 9.8 minutes for Cook closed lavage. The closed technique using the Cook catheter was significantly faster than open lavage. Technical difficulties were significantly less frequent with Cook catheter closed lavage than with Lazarus-Nelson catheter closed lavage. The overall complication rate was 1.8%, and the overall accuracy was 98.1%, without apparent difference among techniques. It is concluded that, when no contraindications to closed lavage exist, and when time is of importance, closed lavage with the Cook catheter is the preferred technique.

Abdominal Injuries

The external rotation method for reduction of acute anterior shoulder dislocation.

Acute anterior shoulder dislocation is a common disorder confronting the emergency physician. Traditional methods of reduction are often technically difficult, time consuming, and painful to the patient. Furthermore, they frequently require more than one physician and occasionally exacerbate the injury. Conversely, the recently described method of reduction by external rotation is a reliable and safe method. A single physician performs the reduction rapidly and patients tolerate it well.

Emergencies

Clinical assessment of patients undergoing CPR in the emergency department.

A problem frequently encountered in the emergency department is assessing the effectiveness of cardiopulmonary resuscitation (CPR), particularly when it is continued over a period of time. To evaluate the effectiveness of CPR in our emergency department we use a mechanical cardiopulmonary resuscitator (Michigan Instruments, Thumper) together with early invasive monitoring of pulse and blood pressure. This also allows for frequent monitoring of blood gases. Three patients are presented who underwent longterm CPR (ie, longer than one hour), and invasive monitoring. Results indicate that better management of the clinical status of patients undergoing prolonged resuscitation can be obtained by using continuous blood pressure and pulse monitoring, and frequent blood gas analysis. In addition, when frequent arrhythmias are taking place, this system allows for better determination of appropriate procedures and medications.

Aged

Defining nursing assignment patterns.

A new way of defining nursing assignment patterns, consistent with current work in studies of organizations, is presented. An instrument has been devised which allows direct measurement of the assignment pattern in use on a patient unit. Although current instrumentation requires continued refinement, the instrument has been used successfully on a dozen patients units to characterize the assignment pattern and appears to be both practical and superior to more conventional methods of characterizing assignment patterns which are now in use.

Humans