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Biomedical subjects

N Nathoo

Publications and source records attributed to N Nathoo.

At least 19 recordsLinked to original sources

Pathobiology of brain metastases.

Brain metastasis is a major cause of systemic cancer morbidity and mortality. Many factors participate in the development and maintenance of brain metastases. The survival of the metastasis depends upon crucial interactions between tumour cells and the brain microenvironment during its development at the new site. This review focuses on the pathobiological mechanisms involved in the establishment and regulation of brain metastases. Developments in molecular biology have vastly expanded our knowledge about the mechanisms of invasion, proliferation, metastatic cell signalling, and angiogenesis in brain metastases. Advances in this understanding of the pathobiology of brain metastasis may lead to novel targeted treatment paradigms and a better prognosis for patients with brain metastatic disease.

Brain Neoplasms↗

The eicosanoid cascade: possible role in gliomas and meningiomas.

Eicosanoids constitute a large family of biologically active lipid mediators that are produced by two enzyme classes, cyclooxygenases (COX-1 and COX-2) and lipoxygenases (5-LO, 12-LO, and 15-LO). Increasing evidence suggests that in addition to a variety of epithelial malignancies, the two most common types of human brain tumour, gliomas and meningiomas, aberrantly overexpress eicosanoid producing enzymes and release a spectrum of eicosanoids that may promote tumorigenesis and the development of peritumorous brain oedema. Glioma and meningioma cells are killed in vitro and in animal models when exposed to COX-2 and 5-LO inhibitors, and their effectiveness is under investigation in clinical trials for treatment of patients with malignant brain tumours. However, despite research into the role of the eicosanoid cascade in the tumorigenesis of human brain tumours, many important questions remain unanswered. Current and newer agents that specifically target key players of the eicosanoid cascade could change the approach to treating brain tumours, because their benefits may lie in their synergism with conventional cytotoxic treatments and/or with other novel agents targeted against other procarcinogenic pathways.

Antineoplastic Agents↗

Genetic vulnerability following traumatic brain injury: the role of apolipoprotein E.

Apolipoprotein E (APOE) is thought to be responsible for the transportation of lipids within the brain, maintaining structural integrity of the microtubule within the neurone, and assisting with neural transmission. Possession of the APOE epsilon4 allele has also been shown to influence neuropathological findings in patients who die from traumatic brain injury, including the accumulation of amyloid beta protein. Previous clinical studies reporting varying outcome severities of traumatic brain injury, including cognitive and functional recovery, all support the notion that APOE epsilon4 allele possession is associated with an unfavourable outcome. Evidence from experimental and clinical brain injury studies confirms that APOE plays an important role in the response of the brain to injury.

Alleles↗

Telemedicine and neurosurgery: experience of a regional unit based in South Africa.

We carried out a retrospective analysis of all emergency referrals to the neurosurgery department of the Wentworth Hospital from 1996 to 1999. The hospital provided a service to seven peripheral hospitals with computerized tomography (CT) scanners and 46 hospitals without, in the province of KwaZulu Natal. By the end of the study, six of the hospitals with CT scanners had facilities for teleradiology and the mean patient return rate had fallen to 17%. In comparison, almost half the patients seen from the hospitals with no CT scanners were returned to hospital after assessment at the Wentworth Hospital. We also carried out a prospective analysis of 100 consecutive teleradiology-assisted consultations from January to March 2000. Of the 57 patients (79%) who remained at their referral hospitals, 45 had a good outcome, while the other 12 (21%) patients had a poor outcome. The implementation of teleradiology-assisted consultation decreased the number of inappropriate inter-hospital transfers while maintaining appropriate patient care and improving outcome.

Adult↗

To determine the effect of metoclopramide on gastric emptying in severe head injuries: a prospective, randomized, controlled clinical trial.

To determine the effect of 8-hourly administration of 10 mg intravenous metoclopramide, over a 48-h period on gastric emptying in severe head injury (SHI), 22 patients were prospectively randomized (Glasgow Coma Score of 3-8) to receive 2 ml of intravenous metoclopramide or 2 ml of 5% saline 8-hourly for 48 h. Baseline and serial blood paracetamol absorption assays were performed at time (t) = 0, 15, 30, 45, 60, 90 and 120 min on day 0 and day 2. The area under the curve between the day 0 and day 2 was used to measure the degree of gastric emptying. In SHI, sequential doses of metoclopramide did not appear to improve gastric motility within subject comparisons (p = 0.65) and between subject comparisons (placebo p = 0.4 and drug p = 0.12). Metoclopramide has no significant prokinetic effect on gastric emptying in SHI patients when given in the early postinjury period.

Adolescent↗

Home-made gun injury: spontaneous version and anterior migration of bullet.

We report a unique case of a self-inflicted brain injury using an ingenious home-made gun with spontaneous anterior migration of the intact bullet. On admission, the patient was fully conscious with no neurological deficits. Computed tomography (CT) confirmed a penetrating missile injury with transventricular across midline trajectory and multi-lobe injury with the bullet lodged in the occipital lobe. Serial CT revealed spontaneous version with anterior migration of the bullet from the occipital lobe to finally come to rest in the ipsilateral frontobasal region. The bullet was removed via a left supra-orbital craniotomy. The patient experienced good outcome. Home-made gun injuries, although uncommon today, represent a special form of missile injury with unique low velocity terminal ballistics. As these weapons are seen infrequently today, surgeons should be alerted to their existence as patients with this form of injury usually have a good prognosis if vital brain structures are spared.

Adult↗

Craniotomy improves outcomes for cranial subdural empyemas: computed tomography-era experience with 699 patients.

OBJECTIVE: Uncertainty regarding the best surgical management for subdural empyemas (SDEs) continues. Our unit has considered craniotomy the preferred method of surgical drainage for all cranial SDEs since 1988. We performed an analysis of our previously published, computed tomography-era, experience with 699 patients. METHODS: Two analyses of the database (1983-1997) were performed. First, analysis of the periods from 1983 to 1987 and from 1988 to 1997 was performed. Second, analysis of the composite database was performed. Outcomes were compared for possible outcome predictors by univariate analysis. Multivariate analysis was used to identify variables that contributed independently to outcomes, using stepwise discriminant analysis. RESULTS: Significant correlations between the analyzed periods with respect to outcome and type of surgery (P = 0.001) were noted. Analysis of the entire database (1983-1997) revealed a significant relationship between outcome and surgery type (P = 0.05). Pairwise comparison of limited procedures such as burr holes or craniectomies with wide-exposure surgical procedures such as primary craniotomies or procedures proceeding to full craniotomies indicated significant correlation with outcomes (P = 0.027). Reoperation and morbidity rates were increased with limited procedures. Stepwise discriminant analyses revealed that the type of surgery was correlated with outcomes (P = 0.0008, partial r(2) = 0.034). CONCLUSION: Craniotomy was determined to be the surgical procedure of choice for treatment of cranial SDEs, allowing complete evacuation of the pus and, more importantly, decompressing the underlying cerebral hemisphere. Limited procedures such as burr holes or craniectomies may be performed for patients in septic shock, for patients with parafalcine empyemas, or for children with SDEs secondary to meningitis.

Craniotomy↗

Longstanding retained foreign bodies in the cranium: a short case report.

Two cases of longstanding retained cranial foreign bodies treated surgically are reported. Patients with longstanding retained foreign bodies may remain clinically well until complications arise. This report emphasizes the importance of maintaining clinical suspicion in mild head injured patients presenting with open scalp wounds, and the value of skull radiographs.

Adult↗

Traumatic cranial empyemas: a review of 55 patients.

A 15-year (1983-1997) review of our unit's computed tomographic experience with traumatic cranial empyema (TCE) is reported. Fifty-five patients with documented history and clinical evidence of neurotrauma with secondary cranial empyema at surgery were identified. The clinical records and CT scans were analysed. TCE [four extradural and 51 subdural collections (SDE)] accounted for 7.86% of the total cranial empyemas seen during the study period. Most of the patients were young males (44 patients) and neurological deficits on admission were found only in the SDE group. Forty-one of 53 patients presented with septic compound skull fractures. Fifty-four patients had urgent surgical drainage. Eighty per cent of patients experienced a good outcome (GOS 4 or 5). A morbidity of 16.4% (including postoperative seizures) was noted and eight patients died (mortality rate 14.5%). Urgent surgical drainage, removal of osteitic bone, wound debridement and high dose intravenous antibiotic therapy form the mainstay of treatment.

Adolescent↗

Role of cerebrospinal fluid shunting for human immunodeficiency virus-positive patients with tuberculous meningitis and hydrocephalus.

OBJECTIVE: Tuberculous meningitis (TBM) and its complications continue to have devastating neurological consequences for patients. Budgetary constraints, especially in developing countries, have made it necessary to select patients for shunting who are likely to experience good recoveries. To date, the value of cerebrospinal fluid shunting for human immunodeficiency virus (HIV)-positive patients with TBM has not been clearly established. METHODS: Thirty patients with TBM and hydrocephalus were prospectively evaluated. Coincidentally, one-half of the patients were HIV-positive. All patients underwent uniform treatment, including ventriculoperitoneal shunt placement and antituberculosis treatment. CD4 counts were measured for all patients. Outcomes were assessed at 1 month. RESULTS: No complications related to shunt insertion were noted. The HIV-positive group fared poorly (death, 66.7%; poor outcome, 64.7%), compared with the HIV-negative group (death, 26.7%; poor outcome, 30.8%). Despite cerebrospinal fluid shunting, no patient in the HIV-positive group experienced a good recovery (Glasgow Outcome Scale score of 5). This is in contrast to the six patients (40%) in the HIV-negative group who, with the same treatment, experienced good recoveries (Glasgow Outcome Scale scores of 5) at discharge (P<0.14). No patient (either HIV-positive or HIV-negative) who presented in TBM Grade 4 survived, whereas no HIV-positive patient who presented in TBM Grade 3 survived. A significant relationship was noted between CD4 counts and patient outcomes (P<0.031). CONCLUSION: In the absence of obvious clinical benefit, HIV-positive patients with TBM should undergo a trial of ventricular or lumbar cerebrospinal fluid drainage, and only those who exhibit significant neurological improvement should proceed to shunt surgery.

AIDS-Related Opportunistic Infections↗

Transcranial brainstem stab injuries: a retrospective analysis of 17 patients.

OBJECTIVE: Transcranial stab injuries remain a frequent cause of emergent neurosurgical admissions to neurosurgical units in South Africa. Brainstem stabs are an uncommon, yet often fatal, form of brain injury. METHODS: A retrospective audit of 597 patients with transcranial stab injuries admitted to our unit over a 12-year period (January 1987 to December 1998) identified 17 patients (2.85%) with brainstem stab injuries. The computed tomographic scans of all patients were analyzed, and a detailed autopsy examination of the skull and its contents was performed in all patients who died. Stepwise linear regression analysis was used to formulate a predictive model of outcome for the entire series of 597 patients. RESULTS: The majority of the patients were males (16 patients), and the study group had a mean age of 28.65 +/- 9.59 years and a mean Glasgow Coma Scale score of 8.59 +/- 2.76. Knives (82%) were the most common instruments of penetration. Cerebral angiography identified 3 patients with vascular abnormalities, and autopsy revealed an additional 4 patients with vascular injury. Emergency ventriculostomy was performed in 10 patients for obstructive hydrocephalus. Four of the 17 patients survived (76.5% mortality). Factors significantly predictive of outcome in patients with transcranial stab injuries were the Glasgow Coma Scale score (F = 43.7), the occurrence of intraventricular hemorrhage (F = 22.8), the type of associated lesion (intracranial bleed, vascular abnormality, or brain abscess) (F = 5.9), and the number of operations (F = 3.2). CONCLUSION: The Glasgow Coma Scale score is the most significant predictor of outcome in low-velocity transcranial stab injuries. Brainstem stab injuries have a great propensity for vascular damage. Survivors are incapacitated by severe, fixed neurological deficits.

Adult↗