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Biomedical subjects

H Mumtaz

Publications and source records attributed to H Mumtaz.

13 recordsLinked to original sources
PubMed2000

Central venous catheter placement in patients with disorders of hemostasis.

BACKGROUND: Patients requiring central venous access frequently have disorders of hemostasis. The aim of this study was to identify factors predictive of bleeding complications after central venous catheterization in this group of patients. METHODS: A retrospective analysis of all central venous catheters placed over a 2-year period (1997 to 1999) at our institution were performed. The age, sex, clinical diagnosis, most recent platelet count, prothrombin international normalized ratio (INR), activated partial thromboplastin time (aPTT), catheter type, the number of passes to complete the procedure, and bleeding complications were retrieved from the medical records. RESULTS: In a 2-year period, 2,010 central venous catheters were placed in 1,825 patients. Three hundred and thirty placements were in patients with disorders of hemostasis. In 88 of the 330 patients, the underlying coagulopathy was not corrected before catheter placement. In these patients, there were 3 bleeding complications requiring placement of a purse string suture at the catheter entry site. In the remaining 242 patients, there was 1 bleeding complication. Of the variables analyzed, only a low platelet count (<50 x 10(9)/L) was significantly associated with bleeding complications. CONCLUSION: Central venous access procedures can be safely performed in patients with underlying disorders of hemostasis. Even patients with low platelet counts have infrequent (3 of 88) bleeding complications, and these problems are easily managed.

Blood Coagulation Disorders↗
PubMed1997

An immunocytochemical study of MHC class I expression on human Langerhans cells and melanocytes.

Classical MHC class I glycoproteins (HLA-A, B, and C) present endogenous cytosolic peptide antigen fragments to CD8-positive T-cells. CD8-positive T-cell recognition and destruction of virus-infected cells are dependent on adequate cellular MHC class I expression. Constitutive MHC class I expression is ubiquitous, but known to be deficient on specific differentiated cell types which include hepatocytes, neurones, chondrocytes and myocytes. Although enabling assessment of MHC class I expression on individual cells, limitations of immunocytochemistry were encountered with this assessment on Langerhans cells and melanocytes. These dispersed intraepidermal cells were obscured by adjacent keratinocytes in sections immunostained for MHC class I glycoproteins. Initiatives designed to resolve the issue have included immunoelectron microscopy, cell culture techniques, and animal bone marrow chimera models. Despite the elegance of these techniques, the issue of MHC class I expression on Langerhans cells and melanocytes remains unresolved. In this immunocytochemical study, an alternative strategy was based upon the recognized deficiency of epithelial MHC class I expression within pilosebaceous adnexal units. Langerhans cells and melanocytes were therefore studied within this microenvironment of deficient MHC class I expression, using monomorphic and polymorphic MHC markers. Langerhans cells and melanocytes were demonstrated within pilosebaceous units of scalp skin by immunocytochemistry. Differentiation markers OKT6 (CD1a) and TMH1 defined Langerhans cells and melanocytes, respectively. Monomorphic MHC markers W6/32 and TAL IB5 defined invariant epitopes of HLA class I and II, respectively. Polymorphic MHC class I markers defined the HLA-Bw4 and HLA-Bw6 supertypic determinants. Constitutive MHC class I expression was shown to be deficient on Langerhans cells and melanocytes.

Hair Follicle↗
PubMed1997

Breast MR and the appearance of the normal and abnormal nipple.

AIM: To identify the magnetic resonance (MR) morphological and enhancement characteristics of the normal and diseased nipple. MATERIALS AND METHODS: The MR appearances of the nipple in 35 patients with known primary breast cancer who went on to mastectomy was reviewed by two radiologists (blinded to the clinical, mammographic and histopathological information) and correlated with histology. The appearance of the contra-lateral nipple in 31 patients was reviewed and compared with that of the affected side. MR was performed at 1.0T using a receive-only double breast coil in 33 patients and a single breast coil in two patients. Three dimensional (3-D) T1-weighted gradient-echo images were made before and immediately after a fast hand injection of gadolinium-DTPA (0.1 mmol/kg). RESULTS: Twenty-six breasts had histopathologically normal nipples and retroareolar tissue, four had evidence of tumour within the nipple and four had retroareolar tumour but with nipple sparing. Fifteen normal nipples were everted and 11 were inverted (flat). All showed superficial linear dermal enhancement above a non-enhancing zone in the nipple areolar complex. Linear or patchy enhancement deep to the non-enhancing zone was seen in four breasts and linear enhancement through the non-enhancing zone was seen in two. The nipple in all four breasts with tumour involvement showed increased thickening/bulkiness and enhancement of the nipple-areolar complex and retroareolar tissue. The four breasts with retroareolar tumour and nipple sparing showed increased thickening and enhancement of the retroareolar tissue only. There was one false positive result on breast MR for retroareolar tumour involvement. In this case the abnormally enhancing retroareolar tissue adjacent to the focal mass was shown to be an area of sclerosing adenosis on histology. The 31 contra-lateral nipples had the characteristic 'normal' appearance and when compared with its normal ipsilateral nipple showed marked symmetry. When compared with its abnormal ipsilateral nipple showed marked asymmetry. CONCLUSION: MR of the breast can show nipple involvement even when clinically unsuspected. This is important for treatment planning of breast cancer, in particular nipple preserving surgery.

Adult↗
PubMed1997

Staging of symptomatic primary breast cancer with MR imaging.

OBJECTIVE: This study was designed to investigate the accuracy of contrast-enhanced MR imaging in the locoregional staging of symptomatic primary breast cancer and to determine the impact of contrast-enhanced MR imaging in planning surgical management. MATERIALS AND METHODS: Ninety patients with primary breast cancer (including two bilateral cancers) diagnosed and treated on the basis of conventional triple assessment (clinical, cytologic, and mammographic examination) underwent MR imaging at 1.0 T using a three-dimensional fast low-angle shot T1-weighted pulse sequence before and after contrast enhancement. A short inversion time inversion recovery sequence was also obtained to evaluate the axilla of each patient. After resection, tumors were histopathologically mapped in detail and correlated with the extent of contrast enhancement on MR imaging. RESULTS: On the basis of triple assessment, 53 cancers were treated by wide local excision, of which 17 (32%) had positive margins at excision. Residual disease at reexcision was detected in eight of these 17 patients, a finding that correlated accurately with the extent of contrast enhancement on MR imaging. MR imaging was more accurate than mammography in determining invasive tumor size (r2 = .93 versus r2 = .59), in depicting multifocality and extensive intraductal component (sensitivity, 81% versus 62%), and in assessing nipple-retroareolar complex. MR imaging-histopathologic correlation was possible in 75 axillae. Sensitivity and specificity for axillary node metastases were 90% and 82%, respectively. CONCLUSION: MR imaging of the breast has value in the preoperative locoregional staging of symptomatic primary breast cancer and is useful in planning a single definitive surgical resection in patients with breast cancer.

Adult↗
PubMed1997

Comparison of magnetic resonance imaging and conventional triple assessment in locally recurrent breast cancer.

BACKGROUND: Magnetic resonance imaging (MRI) was compared with triple assessment (clinical examination, cytology and mammography) in the differentiation of post-treatment changes from local recurrence of breast carcinoma. METHODS: Thirty patients treated previously by breast conservation surgery and radiotherapy with clinical suspicion of local recurrence were evaluated prospectively by triple assessment and MRI. Breast MRI was performed on a 1-tesla scanner using a T1-weighted three-dimensional fast low angle shot pulse sequence before and after contrast enhancement. RESULTS: Local recurrence was confirmed histologically in 14 patients. Of these, mammography identified seven (sensitivity 50 per cent), cytology 11 (sensitivity 79 per cent) and breast MRI 13 (sensitivity 93 per cent). Compared with histological measurement, breast MRI allowed an accurate estimation of the extent of local recurrence (r2 = 0.98). Morphologically abnormal areas without contrast enhancement correlated with postradiation changes. False-positive contrast enhancement was seen in two patients (specificity 88 per cent) in whom histology confirmed inflammatory changes only. CONCLUSION: Breast MRI is useful in the evaluation of patients with a high clinical suspicion of local recurrence within the irradiated conserved breast.

Adult↗
PubMed1996

Breast surgery after neoadjuvant treatment. Is it necessary?

The optimum management of women with advanced loco-regional breast cancer (T3-4, N1-2) is controversial. Neoadjuvant therapy in the form of chemotherapy and or radiotherapy is popular and results in an encouraging local response in over 70% of patients. However, should subsequent surgery (either mastectomy or breast conservation treatment) be undertaken in women who respond? We present a prospective evaluation of 15 patients with T3-4, N1-2 tumours (including 1 bilateral cancer) who underwent mastectomy after achieving a complete clinical response to neoadjuvant treatment. All patients had 6 cycles of chemotherapy and 10 also received 50 Gy radiotherapy. In addition to clinical examination, the response to neoadjuvant treatment was assessed by mammography (in all cases) and by magnetic resonance imaging (MR) (in eight patients). Careful histopathological assessment of the breast was undertaken to determine the extent of residual disease. In all patients histological malignancy was recognized within the breast. The size varied from 0.6 to 6.5 cm in maximum diameter with three grade I, eight grade II and five grade III tumours. Axillary lymph nodes were positive in seven patients. In conclusion, surgery is indicated for control of residual disease in locally advanced breast cancer regardless of the response to neoadjuvant treatment. Our preliminary observations suggest a potential role for breast MR in defining the extent of residual disease which may aid in the planning of surgery.

Adult↗
PubMed1996

Laser therapy for breast cancer: MR imaging and histopathologic correlation.

PURPOSE: To investigate magnetic resonance (MR) imaging guidance of interstitial laser photocoagulation to treat primary breast cancer. MATERIALS AND METHODS: Twenty female patients with symptomatic breast cancers diagnosed at cytologic examination underwent interstitial laser photocoagulation by means of a single fiber prior to surgical excision. Gadolinium-enhanced T1-weighted three-dimensional fast low-angle shot (FLASH) MR imaging was performed before and after laser therapy (median, 48 hours; range, 24-96 hours). Following resection, tumors were mapped in detail histopathologically. The extent of disease, size of laser burn, and extent of residual tumor were correlated with MR findings. RESULTS: Twenty-seven tumors were detected at histopathologic examination in the 20 patients. Five patients had more than one invasive mass. Twenty-five of the 27 tumors were identified as discrete enhancing masses at MR. The two missed invasive foci were obscured on MR images by diffuse patchy enhancement that correlated with the presence of an associated extensive intraductal component. Early (4-hour) follow-up images failed to depict the laser effect. Later (24-96 hours) follow-up images depicted the laser-induced necrosis as a zone of nonenhancement within the residual enhancing tumor. The correlation coefficients (MR vs histopathologic analysis) for the laser-burn diameter and residual tumor were 0.80 and 0.86, respectively. CONCLUSION: Delayed gadolinium-enhanced MR images can help define the extent of laser-induced necrosis and residual tumor after interstitial laser photocoagulation therapy in breast cancer.

Adult↗
PubMed1996

Myocardial perfusion scintigraphy in patients undergoing major non-vascular abdominal surgery.

The prognostic value of myocardial perfusion scintigraphy is beginning to be recognised in patients undergoing cardiovascular surgery. The aim of this prospective study was to assess the predictive value of scintigraphy in elderly patients undergoing major non-vascular abdominal surgery. Adenosine stress thallium-201 (201Tl) single-photon emission tomography (SPET) was employed for imaging using a standard protocol. Patients over the age of 60 years (n = 55) with an intermediate to high likelihood of coronary artery disease were evaluated prospectively. The clinical outcome variables analysed were cardiac mortality and major cardiac morbidity occurring within 30 days of surgery. Cardiac events were cardiac death (n = 5), angina pectoris (n = 5), nonfatal mycardial infarction (n = 1), acute left ventricular failure (n = 2) and arrhythmias requiring treatment (n = 4). All cardiac events occurred in the first 10 postoperative days except one cardiac death which happened on the 29th postoperative day. Patients with an abnormal 201Tl SPET scan had a higher risk of postoperative death (4 vs 1) or any postoperative cardiac event (13 patients vs 4 patients; P < 0.0001) when compared with those with a normal scan. The sensitivity, specificity and positive predictive value of 201Tl imaging for perioperative ischaemia and adverse outcomes were 76%, 82% and 65%, respectively. The occurrence of an intraoperative event (P < 0.02) and the length of surgery (P < 0.01) were also predictors of a postoperative cardiac event. Clinical risk variables and an abnormal electrocardiogram in isolation were poor predictors. In conclusion, preoperative myocardial perfusion scintigraphy is a valuable technique for identifying elderly patients with a high risk for cardiac events when undergoing major non-vascular abdominal surgery.

Abdomen↗
PubMed1976

Gastrointestinal tuberculosis.

Gastrointestinal tuberculosis continues to occur sporadically in hospitals in the British Isles. Accurate diagnosis may enable its rare but lethal complications to be anticipated. Pathology, clinical features and treatment are reviewed. The use of antituberculous chemotherapy and corticosteroids is discussed with reference to 14 cases of gastrointestinal tuberculosis seen in Southampton between 1951 and 1973.

Adrenal Cortex Hormones↗