Quantitative proton MRS of Pelizaeus-Merzbacher disease: evidence of dys- and hypomyelination.
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Brain↗
Biomedical subjects
Omar A Khan
Publications and source records attributed to Omar A Khan.
Herpes encephalitis presenting as mild aphasia: case report.
BACKGROUND: Encephalitis presenting as a change in mental status can be challenging to recognize in the primary care setting. However, early detection via a low threshold of suspicion can be useful, leading in turn to early treatment and improved survival. CASE PRESENTATION: We present a case which we consider relevant to primary care practitioners. The patient in question presented with relatively mild mental status changes, progressing to confusion, dysnomia and delirium over a period of three days. While infection did not appear to be the leading cause on her differential diagnosis, she was found on extensive workup to have encephalitis caused by Herpes Simplex Virus type 1. CONCLUSION: The case is instructive for general practitioners and other clinicians to maintain vigilance for central nervous system (CNS) infections which may present atypically.
Acyclovir↗
Routine histological analysis of resected lung tissue in primary spontaneous pneumothorax -- is it justified?
Surgical management of spontaneous primary pneumothorax consists of pleurectomy together with resection of blebs or bullae. We analysed the utility of routine histological examination of these resected specimens. A consecutive series of 64 resected specimens were reviewed, of which 43 (67%) showed the presence of bullae or blebs. Of the remainder, 20 (31%) specimens showed no evidence of bullae or blebs and 1 specimen showed the presence of pneumatocoeles. Examination of the lung parenchyma revealed inflammation in 34 (53%) cases. In all 64 cases, the histological results did not result in a change in medical therapy. Although resected lung specimens from patients with primary spontaneous pneumothorax show diversity in their histological characteristics, we would question the utility of routine pathological analysis of resected lung specimens in primary spontaneous pneumothorax.
Acute Disease↗
Survival after esophageal resection for carcinoma: the importance of the histologic cell type.
BACKGROUND: The significance of tumor cell type on survival after esophageal resection for carcinoma is uncertain. We reviewed our experience in order to compare the outcome in the two main histologic groups. METHODS: Between January 1987 and April 2000, 621 patients underwent esophagectomy with curative intention for squamous cell carcinoma or adenocarcinoma. The postoperative outcomes of patients with adenocarcinoma and squamous cell carcinoma were compared. RESULTS: Of the cohort, 424 patients had adenocarcinoma (group A) and 197 had squamous cell carcinoma (group B). The commonest approach in group A was a left thoracotomy (67%), while in group B, it was an Ivor Lewis resection (55%) (p < 0.0001). Operative mortality was 3.5% for group A and 8.1% for group B (p = 0.03). Cardiorespiratory complication rate was similar, but anastomotic leaks occurred more frequently in group B (4.2% vs 8.6%, p = 0.04). Patients in group B tended to have earlier pathologic tumor, node, metastasis (pTNM) stage (p = 0.06). Overall, survival was significantly better for group B (p = 0.003). Group B had a significantly better survival than group A in lymph node (LN) negative status (p = 0.01), and a relatively improved survival in LN positive status (p = 0.35). On multivariate analysis, squamous cell subtype (p = 0.034), pTNM stage (p = 0.005), LN status (p = 0.008), and completeness of resection (p = 0.028) were significant predictors of survival. CONCLUSIONS: After esophagectomy, patients with squamous cell carcinoma have a poorer perioperative outcome as compared with those with adenocarcinoma. However, in the longer term, squamous cell type appears to confer a significant survival advantage.
Adenocarcinoma↗
Effects of pre-natal and early post-natal undernutrition on adult internal thoracic artery function.
OBJECTIVE: Previous studies in humans and animals have suggested that undernutrition in utero and in early post-natal life may lead to altered vascular function in a number of peripheral arteries. We investigated the effect of pre- and post-natal nutrient restriction on the vascular reactivity of the left internal thoracic artery using a sheep model. METHODS: Welsh mountain ewes were mated and assigned to three dietary groups: (1) 100% of total nutritional requirements (control, n=6); (2) 50% of total nutritional requirements during the first 31 days of gestation (n=6); and (3) 50% nutritional restriction during the first 31 days of gestation, followed by a restriction in the diet of their offspring 12-25 weeks post-natally, designed to produce a 15% reduction in growth trajectory (n=7). The male offspring were sacrificed at 130 weeks; the left internal thoracic artery was mounted onto a wire myograph and the reactivity of the vessel to various agonists measured. RESULTS: The offspring of animals who underwent an early gestation nutrient restriction had a significantly increased basal tone (0.41+/-0.25 vs 6.34+/-1.35, p=0.015) and sensitivity to phenylephrine (log EC(50): -6.23+/-0.04 M vs -5.74+/-0.17 M, p=0.036) as compared with control animals. However, this phenomenon was not seen in animals that underwent both pre- and post-natal nutrient restriction. CONCLUSIONS: Pre-natal undernutrition increases the basal tone and sensitivity of the left internal thoracic artery to phenylephrine. This effect is significantly attenuated by continued undernutrition in early post-natal life. These experiments suggest that in utero and early post-natal undernutrition may be important determinants of graft function in later life.
Animal Nutritional Physiological Phenomena↗
Fetal origins of coronary heart disease-implications for cardiothoracic surgery?
Over the last 15 years, there has been growing evidence that poor nutrition during gestation plays an important role in the development of coronary heart disease. This hypothesis, commonly known as the 'fetal origins of adult disease' has now gained widespread acceptance in the scientific community. In this review, we discuss the evidence for this theory and analyse the patho-physiological mechanisms underlying the relationship between altered fetal growth and coronary heart disease. Finally, the potential relevance of the theory to cardiac surgical practice will be evaluated.
Adult↗
Recurrent spontaneous esophageal rupture.
Spontaneous esophageal rupture is an uncommon and poorly understood condition. Recurrent rupture is extremely rare, with only one previously reported case in the literature. Here, we present a case series of two patients who had recurrent ruptures, and discuss the principles underlying the management of such cases.
Esophageal Diseases↗
Histological determinants of survival in completely resected T1-2N1M0 nonsmall cell cancer of the lung.
BACKGROUND: The histologic determinants of survival after surgical resection of stage II nonsmall cell lung cancer are poorly understood. We analyzed the prognostic significance of a number of histologic features after complete resection of T1-2N1M0 nonsmall cell cancer of the lung. METHODS: The case notes and histology of all patients who underwent a potentially curative surgical resection for T1-2N1M0 nonsmall cell carcinoma of the lung between 1991 and 1997 were reviewed retrospectively. The following histologic factors were recorded: histologic type of tumor; number of nodes with metastatic deposits together with their nodal station; the presence of vascular invasion, visceral pleural involvement, and cellular necrosis; and grade of tumor. The results from 98 patients were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors. RESULTS: Univariate analysis showed that only three factors had a statistically significant correlation with a poor prognosis: vascular invasion (p = 0.002), nonsquamous histology (p = 0.005), and visceral pleural involvement (p = 0.002). Multivariate analysis revealed that all three factors were significant independent adverse prognostic indicators. CONCLUSIONS: Visceral pleural involvement, nonsquamous histology, and vascular invasion are all significant adverse prognostic factors after surgical resection of T1-2N1M0 nonsmall cell cancer of the lung. These findings conflict with previously published reports, and we advocate a prospective, large-scale study in order to clarify the prognostic significance of histologic characteristics in stage II disease.
Carcinoma, Non-Small-Cell Lung↗
Redo antireflux surgery--the importance of a tailored approach.
OBJECTIVE: Although several studies have examined early outcome following redo antireflux surgery, there is little data on the long-term efficacy of these procedures. We reviewed our experience of these operations in order to assess the long-term results which can be achieved by choosing redo antireflux procedures based on the results obtained from pre-operative oesophageal function testing. METHODS: The case notes of 26 patients who underwent a repeat antireflux procedure between 1981 and 2000 were reviewed. Clinical history, examination, endoscopy, pH studies, oesophageal manometry and video barium contrast studies were performed on all patients prior to re-operation. In all cases, a standardised pre-formulated algorithm, based on the results of the pre-operative oesophageal function tests, was used to determine the choice of surgical procedure. Post-operatively, patients were classified into three groups: Group A (those with no symptoms), Group B (symptoms controlled by medication) and Group C (symptoms refractory to medical treatment). Patients in Groups B and C underwent repeat oesophageal function studies. RESULTS: In all cases, the indication for re-operation was gastro-oesophageal reflux symptoms refractory to medical treatment. Twenty-one patients (81%) underwent a left thoracotomy, of whom 11 patients (42%) underwent a gastroplasty. The mean follow-up period was 8.27 years (range 1.5-19.8 years), after which 14 patients (54%) were classified as Group A; 10 patients (38%) as Group B; and 2 patients (8%) as Group C. Within Groups B and C, manometry showed that re-operation had increased basal lower oesophageal sphincter pressure (4.6 vs 12.7 mmHg, pre- vs post-operative P=0.03), and in all, but one case pH studies showed no evidence of recurrent acid reflux. CONCLUSIONS: Redo antireflux surgery can provide complete symptomatic relief in approximately 50% of patients and symptomatic improvement over 90% of patients. We advocate a tailored approach in the selection of re-operative procedures based on the results of pre-operative oesophageal function testing.
Adolescent↗
A controlled trial of natalizumab for relapsing multiple sclerosis.
BACKGROUND: In patients with multiple sclerosis, inflammatory brain lesions appear to arise from autoimmune responses involving activated lymphocytes and monocytes. The glycoprotein alpha4 integrin is expressed on the surface of these cells and plays a critical part in their adhesion to the vascular endothelium and migration into the parenchyma. Natalizumab is an alpha4 integrin antagonist that reduced the development of brain lesions in experimental models and in a preliminary study of patients with multiple sclerosis. METHODS: In a randomized, double-blind trial, we randomly assigned a total of 213 patients with relapsing-remitting or relapsing secondary progressive multiple sclerosis to receive 3 mg of intravenous natalizumab per kilogram of body weight (68 patients), 6 mg per kilogram (74 patients), or placebo (71 patients) every 28 days for 6 months. The primary end point was the number of new brain lesions on monthly gadolinium-enhanced magnetic resonance imaging during the six-month treatment period. Clinical outcomes included relapses and self-reported well-being. RESULTS: There were marked reductions in the mean number of new lesions in both natalizumab groups: 9.6 per patient in the placebo group, as compared with 0.7 in the group given 3 mg of natalizumab per kilogram (P<0.001) and 1.1 in the group given 6 mg of natalizumab per kilogram (P<0.001). Twenty-seven patients in the placebo group had relapses, as compared with 13 in the group given 3 mg of natalizumab per kilogram (P=0.02) and 14 in the group given 6 mg of natalizumab per kilogram (P=0.02). The placebo group reported a slight worsening in well-being (a mean decrease of 1.38 mm on a 100-mm visual-analogue scale), whereas the natalizumab groups reported an improvement (mean increase of 9.49 mm in the group given 3 mg of natalizumab per kilogram and 6.21 mm in the group given 6 mg of natalizumab per kilogram). CONCLUSIONS: In a placebo-controlled trial, treatment with natalizumab led to fewer inflammatory brain lesions and fewer relapses over a six-month period in patients with relapsing multiple sclerosis.
Adult↗
The global and local impact of malaria: a case report from Delaware, advances in treatment, and recommendations for travelers.
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Adult↗