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Biomedical subjects

D F Kelly

Publications and source records attributed to D F Kelly.

At least 37 records · Page 2Linked to original sources

Advances in management of neurosurgical trauma: USA and Canada.

Traumatic brain and spinal cord injuries continue to pose serious challenges for physicians around the world. In North America, the annual number of serious head and spinal injuries has decreased over the last two decades, and of those patients who reach a hospital, the mortality and long-term morbidity have also declined. The two major reasons for this reduction in death and disability after craniospinal trauma in the United States and Canada appear to be (1) widespread implementation of prevention measures, safety legislation, and public education initiatives; and (2) further improvements in and wider availability of emergency medical systems and regional trauma centers. Improvements in neurocritical care and the implementation of evidence-based treatment guidelines for severe head injury victims may also, in part, be responsible for improved survival rates and reduced disability rates. Unfortunately, numerous clinical trials of putative neuroprotective agents conducted in North America and elsewhere during the 1990s have failed to demonstrate efficacy in head-injured patients. However, methylprednisolone does appear to confer some benefit to a select population of spinal cord injury patients. These advances in the areas of prevention, regional trauma systems, treatment guidelines, and neurocritical care that have influenced survival rates and recovery of function are discussed.

Brain Injuries↗

Carbohydrate-deficient glycoprotein syndrome 1b: a new answer to an old diagnostic dilemma.

A patient with carbohydrate-deficient glycoprotein syndrome type 1b (CDGS1b) is reported. The patient presented at 5 months of age with failure to thrive, prolonged diarrhoea, hepatomegaly and elevated serum liver transaminases. Liver biopsy showed steatosis. A low serum albumin and elevated serum liver transaminases persisted throughout childhood during which he had repeated infectious illnesses. From the age of 10 years he had oesophageal and duodenal ulceration together with recurrent bacterial cholangitis. Liver biopsy demonstrated hepatic fibrosis. CDGS1b was suspected, supported by the finding of a protein-losing enteropathy and finally confirmed by showing a reduced phosphomannoseisomerase activity. This case illustrates a rare condition with a wide range of presentations.

Adolescent↗

Experimental studies on the transmission of Neospora caninum between cattle.

Three studies were conducted to investigate the transmission of Neospora caninum between cattle by the oral route. In the first study, six calves were dosed with 10(7)N caninum tachyzoites (NC LivB1) in colostrum and/or milk replacer on four occasions. In the second study, two calves and two cows were fed placental tissues from N caninum -infected cows, and, in the third study, seven uninfected calves were fostered onto N caninum -infected dams. In the first study, all six calves developed antibody responses and five calves developed antigen-specific lymphoproliferation responses, including two calves initially challenged at 1 week of age. No evidence of N caninum infection was found in the brain or heart of these calves by histology or polymerase chain reaction (PCR). In the second and third studies, there was no evidence of N caninum infection in any of the calves and cows. The results confirm that calves up to 1 week of age can be experimentally infected via the oral route, but suggest that this is not an important natural route of transmission for N caninum between cattle.

Animals↗

Collagen sponge repair of small cerebrospinal fluid leaks obviates tissue grafts and cerebrospinal fluid diversion after pituitary surgery.

OBJECTIVE: Repair of a cerebrospinal fluid (CSF) leak created at the time of transsphenoidal surgery typically involves placement of a fat, fascial, or muscle graft and sellar floor reconstruction. In this report, a simplified repair for small, "weeping" CSF leaks using collagen sponge is described. METHODS: All patients underwent an endonasal transsphenoidal procedure using the operating microscope. At the completion of tumor removal, if a small CSF leak was noted but no obvious large arachnoidal defect was present, a piece of collagen sponge was fashioned to cover the exposed diaphragma sellae. Titanium mesh was then wedged into the intrasellar, extradural space and a larger piece of collagen was placed over the reconstructed sellar floor. Nasal packing was removed within 24 hours. RESULTS: During an 18-month period, 62 consecutive transsphenoidal procedures were performed for tumor removal. Of 20 patients with a small CSF leak (18 pituitary adenomas, 1 Rathke's cleft cyst, and 1 chordoma), all had successful repair with collagen sponge. At follow-up examinations at 1 to 18 months, no patient had required a lumbar drain or had developed meningitis. One other patient had a large intraoperative arachnoidal defect that was unsuccessfully repaired with the collagen sponge technique; in this patient, a second operation was required with a fat graft, sellar floor reconstruction, and lumbar drainage. CONCLUSION: A simplified repair of small CSF leaks after transsphenoidal surgery using a two-layered collagen sponge technique with sellar floor reinforcement is thought to be safe and effective and obviates the need for tissue grafts, fibrin glue, or lumbar drain placement.

Adenoma↗

Auricular chondritis in a cat.

A four-year-old male neutered domestic shorthaired cat developed bilateral thickening of the pinnae, with slight curling, intense erythema and pain. No ear canal disease was present. The cat was negative for feline immunodeficiency virus, feline leukaemia virus and feline coronavirus. Biopsy of the ear lesion revealed auricular chondritis. In humans, histologically similar lesions may involve the pinnae, nose, trachea, joints, eyes and heart, and the disease is termed relapsing polychondritis. The cat reported had a history of corneal damage, resulting in corneal vascularisation and opacity, eyelid distortion, necessitating an entropion operation, and radiological evidence of mild cardiac enlargement. The ear disease responded rapidly to treatment with prednisolone and, apart from slight thickening and curling of the pinnae, the cat remained normal and pain-free. After two years, the prednisolone was withdrawn, and there was no recurrence of the condition in a follow-up period of 14 months.

Animals↗

Carbon dioxide reactivity, pressure autoregulation, and metabolic suppression reactivity after head injury: a transcranial Doppler study.

OBJECT: Contemporary management of head-injured patients is based on assumptions about CO2 reactivity, pressure autoregulation (PA), and vascular reactivity to pharmacological metabolic suppression. In this study, serial assessments of vasoreactivity of the middle cerebral artery (MCA) were performed using bilateral transcranial Doppler (TCD) ultrasonography. METHODS: Twenty-eight patients (mean age 33 +/- 13 years, median Glasgow Coma Scale score of 7) underwent a total of 61 testing sessions during postinjury Days 0 to 13. The CO2 reactivity (58 studies in 28 patients), PA (51 studies in 23 patients), and metabolic suppression reactivity (35 studies in 16 patients) were quantified for each cerebral hemisphere by measuring changes in MCA velocity in response to transient hyperventilation, arterial blood pressure elevation, or propofol-induced burst suppression, respectively. One or both hemispheres registered below normal vasoreactivity scores in 40%, 69%, and 97% of study sessions for CO2 reactivity, PA, and metabolic suppression reactivity (p < 0.0001), respectively. Intracranial hypertension, classified as intracranial pressure (ICP) greater than 20 mm Hg at the time of testing, was associated with global impairment of CO2 reactivity, PA, and metabolic suppression reactivity (p < 0.05). A low baseline cerebral perfusion pressure (CPP) was also predictive of impaired CO2 reactivity and PA (p < 0.01). Early postinjury hypotension or hypoxia was also associated with impaired CO2 reactivity (p < 0.05), and hemorrhagic brain lesions in or overlying the MCA territory were predictive of impaired metabolic suppression reactivity (p < 0.01). The 6-month Glasgow Outcome Scale score correlated with the overall degree of impaired vasoreactivity (p < 0.05). CONCLUSIONS: During the first 2 weeks after moderate or severe head injury, CO2 reactivity remains relatively intact, PA is variably impaired, and metabolic suppression reactivity remains severely impaired. Elevated ICP appears to affect all three components of vasoreactivity that were tested, whereas other clinical factors such as CPP, hypotensive and hypoxic insults, and hemorrhagic brain lesions have distinctly different impacts on the state of vasoreactivity. Incorporation of TCD ultrasonography-derived vasoreactivity data may facilitate more injury- and time-specific therapies for head-injured patients.

Adolescent↗

Endoscopic electrosurgical excision of laryngeal granulation tissue in a standing pregnant mare.

An 11-year-old, eight-months pregnant mare suddenly developed severe respiratory distress. Endoscopic examination identified intralaryngeal granulation tissue obstructing the airway. In order to avoid general anaesthesia and the problems associated with a permanent tracheostomy, the mass was resected electrosurgically while the mare was standing. Patency was restored to the airway and the mare foaled without complication.

Airway Obstruction↗

Neospora caninum-associated abortion in cattle: the time of experimentally-induced parasitaemia during gestation determines foetal survival.

The parasite, Neospora caninum is an important cause of abortion in cattle. It is transmitted vertically or horizontally and infection may result in abortion or the birth of a live, healthy but infected calf at full-term. Only a proportion of infected cattle abort and the pathogenesis of abortion is not understood. Groups of cattle were infected with 10(7) N. caninum tachyzoites intravenously at different times relative to gestation. Intravenous inoculation was chosen to reproduce the putative haematogenous spread of N. caninum following either recrudescence of endogenous infection or de novo infection. In all cattle, infection was accompanied by high gamma-interferon and lymphoproliferative responses, and a biased IgG2 response indicating that N. caninum infection is accompanied by a profound Th1 helper T cell-like response. Infection at 10 weeks gestation resulted in foetopathy and resorption of foetal tissues 3 weeks after infection in 5 out of 6 cows. Infection at 30 weeks gestation resulted in the birth of asymptomatic, congenitally-infected calves at full term in all 6 cows, whereas the 6 cows infected before artificial insemination gave birth to live, uninfected calves. These results suggest that the reason some cows abort is related to the time during gestation when they become infected or an existing infection recrudesces.

Abortion, Veterinary↗

Ethanol reduces metabolic uncoupling following experimental head injury.

Previous investigations have shown that ethanol is neuroprotective following experimental traumatic brain injury (TBI). This study sought to determine if the neuroprotective effects of ethanol in a controlled cortical impact (CCI) injury model are related to its effects on cerebral glucose metabolism and blood flow. Adult rats were given ethanol (1.0 g/kg) or saline by intraperitoneal injection followed 40 min later by injury. Regional cerebral blood flow (CBF) and cerebral metabolic rates of glucose (CMRglc) were determined immediately, and at 3, 6, 12, 24, and 72 h postinjury using quantitative autoradiography. Immediately after injury, CMRglc in the contusion core and penumbra was reduced in the ethanol group compared to the saline group: (core CMRglc: 52.2 +/- 16.0 versus 94.2 +/- 14.1 micromol/100 g/min, respectively,p < 0.001; penumbral CMRglc: 58.2 +/- 12.8 versus 82.8 +/-19.7 micromol/100 g/min, respectively; p < 0.05) However, at 24 and 72 h postinjury, penumbral CMRglc in the ethanol group was increased compared to the saline group (p < 0.05 and p < 0.001, respectively). Regarding CBF, contusion core values in the ethanol group were elevated compared to the saline group immediately postinjury, (70.4 +/- 17.1 versus 31.5 +/- 27.8 mL/100 g/min, respectively (p < .05), and at 6, 12, and 24 h postinjury (p < 0.05). Penumbral CBF was also higher at 6 and 72 h in the ethanol group compared to the saline group (p < 0.05). These results indicate that low-dose ethanol is associated with a marked attenuation of immediate postinjury hyperglycolysis and with more normal glucose metabolism in the injury penumbra over the ensuing 3 days. Simultaneously, the reduction in CBF typically seen within the contusion core and penumbra after CCI is less severe when ethanol is present. The net effect of these changes is a decreased degree of uncoupling between glucose metabolism and CBF that otherwise occurs in the absence of ethanol. These changes may likely explain the neuroprotective effect of ethanol.

Animals↗

Dissociation of cerebral glucose metabolism and level of consciousness during the period of metabolic depression following human traumatic brain injury.

Utilizing [18F]fluorodeoxyglucose positron emission tomography (FDG-PET), we studied the correlation between CMRglc and the level of consciousness within the first month following human traumatic brain injury. Forty-three FDG-PET scans obtained on 42 mild to severely head-injured patients were quantitatively analyzed for the determination of regional cerebral metabolic rate of glucose (CMRglc). Reduction of cerebral glucose utilization, defined as a CMRglc of < or =4.9 mg/100 g/min, was present regionally in 88% of the studies. The prevalence of global cortical CMRglc reduction was higher in severely head-injured patients (86% versus 67% mild-moderate), although the absolute magnitude was similar across the injury severity spectrum (mean CMRglc 3.9 +/- 0.6 mg/100 g/min). The level of consciousness, as measured by the Glasgow Coma Scale, correlated poorly with the global cortical CMRglc value (r = 0.08; p = 0.63). With regards to severity of head injury, this correlation was worst for the severely injured (r = -0.11; p = 0.58) and better for the mildly injured patients (r = 0.50; p = 0.07). In most cases, intraparenchymal hemorrhagic lesions were associated with either focal CMRglc reduction or elevation. It is concluded that the etiologies of CMRglc reduction are likely multifactorial given the complex nature of traumatic brain injury and that the reduction of CMRglc represents a fundamental pathobiologic state following head injury that is not tightly coupled to level of consciousness.

Adult↗

Segmental eosinophilic colitis: a review of 22 cases.

Twenty-two horses with colic, referred to the University of Liverpool Equine Hospital (1992-1998), were found at laparotomy to have a partial obstruction of the large colon caused by a segmental mural lesion located in the left dorsal colon. The decision to take the horses to surgery was based on rectal examination findings of secondary impaction and mural oedema of the large colon and turbid peritoneal fluid containing large numbers of neutrophils obtained by paracentesis. The affected segment of colon showed oedema and serosal changes varying from erythema to well-defined necrosis. These pathological changes were considered to be sufficiently severe in 16 horses to merit partial resection of the left colon. Histology revealed varying degrees of mucosal necrosis, marked submucosal oedema and infiltration with large numbers of eosinophilic leucocytes. No cause was identified for the lesions. Sixteen of the 18 horses discharged from the hospital were alive 3 months to 7 years after surgery and have returned to their previous type of work and level of performance. The remaining 2 horses were subjected to euthanasia because of a recurrence of colic but no autopsy was performed.

Animals↗

Anaemia, diarrhoea and opportunistic infections in Fell ponies.

This report summarises clinical and pathological observations on Fell pony foals with a range of signs that included ill thrift, anaemia, respiratory infection, glossal hyperkeratosis and diarrhoea. Some of the foals had normochromic, normocytic anaemia and some had low levels of plasma proteins, including immunoglobulin G. Antibiotic and supportive treatment was ineffective and all affected foals died or were killed on humane grounds. Postmortem examination of 12 foals and tissues from 2 other foals revealed a range of lesions that included glossal hyperkeratosis, typhlocolitis, intestinal cryptosporidiosis, granulomatous enteritis, proliferative and necrotising bronchiolitis consistent with adenovirus infection; lesions similar to those in the respiratory tract were present in the salivary gland and pancreas of individual foals. Lymphoid tissue was judged to be smaller than expected. These observations suggest the possibility of opportunistic infections secondary to some form of undefined immunocompromised state.

Anemia↗

Hypopituitarism following traumatic brain injury and aneurysmal subarachnoid hemorrhage: a preliminary report.

OBJECT: Recognition of pituitary hormonal insufficiencies after head injury and aneurysmal subarachnoid hemorrhage (SAH) may be important, especially given that hypopituitarism-related neurobehavioral problems are typically alleviated by hormone replacement. In this prospective study the authors sought to determine the rate and risk factors of pituitary dysfunction after head injury and SAH in patients at least 3 months after insult. METHODS: Patients underwent dynamic anterior and posterior pituitary function testing. Results of the tests were compared with those of 18 age-, sex-, and body mass index-matched healthy volunteers. The 22 head-injured patients included 18 men and four women (mean age 28+/-10 years at the time of injury) with initial Glasgow Coma Scale (GCS) scores of 3 to 15. Eight patients (36.4%) had a subnormal response in at least one hormonal axis. Four were growth hormone (GH) deficient. Five patients (four men, all with normal testosterone levels, and one woman with a low estradiol level) exhibited an inadequate gonadotroph response. One patient had both GH and thyrotroph deficiency and another had both GH deficiency and borderline cortisol deficiency. At the time of injury, all eight patients with pituitary dysfunction had an initial GCS score of 10 or less and, compared with the 14 patients without dysfunction, were more likely to have had diffuse swelling, seen on initial computerized tomography scans (p < 0.05), and to have sustained a hypotensive or hypoxic insult (p = 0.07). Of two patients with SAH who were studied (Hunt and Hess Grade IV) both had GH deficiency. CONCLUSIONS: From this preliminary study, some degree of hypopituitarism appears to occur in approximately 40% of patients with moderate or severe head injury, with GH and gonadotroph deficiencies being most common. A high degree of injury severity and secondary cerebral insults are likely risk factors for hypopituitarism. Pituitary dysfunction also occurs in patients with poor-grade aneurysms. Postacute pituitary function testing may be warranted in most patients with moderate or severe head injury, particularly those with diffuse brain swelling and those sustaining hypotensive or hypoxic insults. The neurobehavioral effects of GH replacement in patients suffering from head injury or SAH warrant further study.

Adolescent↗

Immunocytochemical demonstration of lymphocyte subsets and MHC class II antigen expression in synovial membranes from dogs with rheumatoid arthritis and degenerative joint disease.

The study describes the distribution of canine leucocyte antigens in synovial membrane biopsies from six dogs with canine rheumatoid arthritis (CRA) and from eight dogs with osteoarthritis (OA) secondary to spontaneous rupture of the cranial cruciate ligament (CCL) (n = 5) or patellar luxation (n = 3). Synovial membranes from five dogs without evidence of joint lesions were used as control tissues. In the subsynovium of dogs with normal joints CD5+, CD4+, CD8+ and alpha beta TCR+ lymphocytes were present only in low numbers. With monoclonal antibody (mAb) to MHC class II antigen, either none or up to 20-30% of synovial lining cells were immunoreactive. Furthermore, scattered MHCII+ stromal cells were seen in the deeper subsynovial layer. In synovial membrane biopsies from dogs with CRA numerous diffusely and perivascularly distributed CD5+ lymphocytes were found in the subsynovium. CD4+ cells outnumbered CD8+ cells and were more numerous in the perivascular areas. In all the CRA cases examined, there were markedly higher numbers of alpha beta TCR+ cells compared with gamma delta TCR+ cells. With mAb to CD21, low numbers of immunoreactive lymphocytes were demonstrated. In all the CRA cases, a marked increase of MHC class II antigen expression was noted. In the majority of samples, 50% or more than 90% of the synovial lining cells were strongly MHC class II+. Throughout the subsynovial layer there were numerous MHC class II+ cells and included those with dendritic morphology and inflammatory mononuclear cells. Furthermore, marked perivascular immunoreactivity for MHC class II antigen was found. In biopsies from dogs with OA, there were markedly lower numbers of subsynovial CD5+, CD4+ and CD8+ lymphocytes. T-cells were mainly diffusely distributed. In three of the eight OA dogs examined, there was an increased percentage of synovial lining cells expressing MHC class II. The majority of OA cases had subsynovial major histocompatibility complex (MHC) class II+ cells with a dendritic morphology.

Animals↗

Propofol in the treatment of moderate and severe head injury: a randomized, prospective double-blinded pilot trial.

OBJECT: Sedation regimens for head-injured patients are quite variable. The short-acting sedative-anesthetic agent propofol is being increasingly used in such patients, yet little is known regarding its safety and efficacy. In this multicenter double-blind trial, a titratable infusion of 2% propofol accompanied by low-dose morphine for analgesia was compared with a regimen of morphine sulfate in intubated head-injured patients. In both groups, other standard measures of controlling intracranial pressure (ICP) were also used. METHODS: Forty-two patients from 11 centers were evaluated to assess both the safety and efficacy of propofol: 23 patients in the propofol group (mean time of propofol usage 95+/-87 hours) and 19 patients in the morphine group (mean time of morphine usage 70+/-54 hours). There was a higher incidence of poor prognostic indicators in the propofol group than in the morphine group: patient age older than 55 years (30.4% compared with 10.5%, p < 0.05), initial Glasgow Coma Scale scores of 3 to 5 (39.1% compared with 15.8%, p < 0.05), compressed or absent cisterns on initial computerized tomography scanning (78.3% compared with 57.9%, p < 0.05), early hypotension and/or hypoxia (26.1% compared with 10.5%, p = 0.07). During treatment there was a trend toward greater use of vasopressors in the propofol group. However, the mean daily ICP and cerebral perfusion pressure were generally similar between groups and, on therapy Day 3, ICP was lower in the propofol group compared with the morphine group (p < 0.05). Additionally, there was less use of neuromuscular blocking agents, benzodiazepines, pentobarbital, and cerebrospinal fluid drainage in the propofol group (p < 0.05). At 6 months postinjury, a favorable outcome (good recovery or moderate disability) was observed in 52.1% of patients receiving propofol and in 47.4% receiving morphine; the mortality rates were 17.4% and 21.1%, respectively. Patients who received the highest doses of propofol for the longest duration tended to have the best outcomes. There were no significant differences between groups in terms of adverse events. CONCLUSIONS: Despite a higher incidence of poor prognostic indicators in the propofol group, ICP therapy was less intensive, ICP was lower on therapy Day 3, and long-term outcome was similar to that of the morphine group. These results suggest that a propofol-based sedation and an ICP control regimen is a safe, acceptable, and, possibly, desirable alternative to an opiate-based sedation regimen in intubated head-injured patients.

Adult↗

Increased incidence and impact of nonconvulsive and convulsive seizures after traumatic brain injury as detected by continuous electroencephalographic monitoring.

OBJECT: The early pathophysiological features of traumatic brain injury observed in the intensive care unit (ICU) have been described in terms of altered cerebral blood flow, altered brain metabolism, and neurochemical excitotoxicity. Seizures occur in animal models of brain injury and in human brain injury. Previous studies of posttraumatic seizures in humans have been based principally on clinical observations without a systematic approach to electroencephalographic (EEG) recording of seizures. The purpose of this study was to determine prospectively the incidence of convulsive and nonconvulsive seizures by using continuous EEG monitoring in patients in the ICU during the initial 14 days post-injury. METHODS: Ninety-four patients with moderate-to-severe brain injuries underwent continuous EEG monitoring begin-ning at admission to the ICU (mean delay 9.6+/-5.4 hours) and extending up to 14 days postinjury. Convulsive and nonconvulsive seizures occurred in 21 (22%) of the 94 patients, with six of them displaying status epilepticus. In more than half of the patients (52%) the seizures were nonconvulsive and were diagnosed on the basis of EEG studies alone. All six patients with status epilepticus died, compared with a mortality rate of 24% (18 of 73) in the nonseizure group (p<0.001). The patients with status epilepticus had a shorter mean length of stay (9.14+/-5.9 days compared with 14+/-9 days [t-test, p<0.031). Seizures occurred despite initiation of prophylactic phenytoin on admission to the emergency room, with maintenance at mean levels of 16.6+/-2.8 mg/dl. No differences in key prognostic factors (such as the Glasgow Coma Scale score, early hypoxemia, early hypotension, or 1-month Glasgow Outcome Scale score) were found between the patients with seizures and those without. CONCLUSIONS: Seizures occur in more than one in five patients during the 1st week after moderate-to-severe brain injury and may play a role in the pathobiological conditions associated with brain injury.

Adolescent↗

Ovarian cancer treatment: the benefit of patient telephone follow-up post-chemotherapy.

Approximately 2,500 women in Canada were diagnosed with cancer of the ovary in 1997 (NCIC, 1997). Standard therapy consists of surgical tumour debulking and cytotoxic chemotherapy. Very little data are available examining the most appropriate outpatient management of patients receiving chemotherapy. The objective of this study was to assess the impact of and benefit received from telephone follow-up between chemotherapy treatments for patients with cancer of the ovary. Patients with cancer of the ovary were treated every three to four weeks with a cisplatin-based chemotherapy. Telephone follow-up was performed five to seven days post-treatment by the gynaecology oncology liaison nurse. Follow-up addressed issues pertinent to treatment and disease side effects. A patient survey addressing the impact of telephone follow-up was performed on a sample of the patient population. Thirty-one patients responded to the survey: Eighty-seven per cent found that receiving a call post-chemotherapy was reassuring and helpful. Eighty-three per cent stated that medications could be adjusted according to the severity of side effects. Eighty per cent of patients agreed that most issues had been dealt with at the time of telephone follow-up. Sixty-four per cent felt that their concerns had been addressed during the phone calls, and only 22% had suggestions on how to improve follow-up. Telephone follow-up during chemotherapy was a valuable tool in assessing patient needs, side effects, and concerns experienced during treatments. Telephone follow-up may facilitate early identification of patient problems allowing appropriate and timely intervention.

Aftercare↗