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Biomedical subjects

D Kahn

Publications and source records attributed to D Kahn.

At least 145 records · Page 8Linked to original sources
PubMed1994

A 15-year experience of injection sclerotherapy in adult patients with extrahepatic portal venous obstruction.

OBJECTIVE: The authors report a 15-year experience with injection sclerotherapy in the management of adult and teenage patients with esophageal varices due to extrahepatic portal venous obstruction (EHPVO). SUMMARY BACKGROUND DATA: Extrahepatic portal venous obstruction is an uncommon cause of esophageal varices and is associated with normal liver function. Effective control of variceal bleeding is the major factor influencing survival. The results of surgery have been unsatisfactory, and therefore, more conservative management policies have been adopted. METHODS: Fifty-five patients with proven EHPVO underwent repeated injection sclerotherapy via either a modified rigid esophagoscope under general anaesthesia or a fiber-optic endoscope under light sedation, using ethanolamine oleate as the sclerosant. RESULTS: Esophageal varices were eradicated in 44 patients after a median number 6 injections (range 1-17) over a mean of 12.5 months (range 1-48). The mean follow-up was 6.8 years (range 1.1-14.6 years). Eleven patients were admitted on eighteen occasions with bleeding from esophageal varices before eradication and there were seven bleeding episodes in six patients from recurrent varices after initial eradication. Complications related to sclerotherapy included injection site leak (6), stenosis (11) and mucosal ulceration (32) during 362 injection sclerotherapy episodes. Four patients died during the study period. CONCLUSIONS: Injection scelotherapy is the treatment of choice in most patients with EHPVO.

Adult↗
PubMed1994

Detection of recurrent colorectal carcinoma with In-111 CYT-103 scintigraphy in a patient with nondiagnostic MRI and CT.

Detection of recurrent colorectal carcinoma can be a diagnostic challenge. The authors report a case of a patient who, after resection of his primary colorectal carcinoma, had a recurrence that was not detected by MRI or serial CT examination, but was clearly demonstrated by In-111 labeled CYT-103 scintigraphy. This case demonstrates the use of CYT-103 scintigraphy in detecting recurrent colorectal cancer in a patient, despite results of nondiagnostic MRI or serial CT examinations.

Adenocarcinoma↗
PubMed1994

Crossed cerebellar diaschisis associated with balloon test occlusion of the carotid artery.

99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO) single photon emission computed tomographic (SPECT) brain imaging performed in conjunction with balloon test occlusion of the carotid artery has been used to assess risk of neurologic sequelae that might follow permanent surgical ligation of the artery. The predictive value of cortical hypoperfusion during temporary carotid occlusion for adverse neurologic events has been debated in previous publications. We believe that the risk of an adverse event is greater when a reduction in cortical perfusion during balloon test occlusion is associated with crossed cerebellar diaschisis (CCD). To test our hypothesis we evaluated the results of 27 99Tcm-HMPAO SPECT brain studies obtained in association with balloon test occlusions of the carotid artery. In each case we correlated clinical outcome with the presence or absence of regional decreases in cerebral perfusion and CCD. All of the 27 patients were free of neurologic symptoms during the balloon test occlusion. Seventeen of the 27 scintigraphic studies were felt to be abnormal, showing cortical perfusion defects all on the side of the occlusion. Among these 17 patients, five demonstrated CCD. Four of these five CCD patients showed evidence for cerebral cortical ischaemia on the side of the temporary carotid occlusion either shortly after the procedure or following carotid artery sacrifice. Of the remaining 12 patients with regionally reduced cerebral perfusion and no CCD, none showed evidence for cortical ischaemia in association with balloon test occlusion, and five of these 12 patients had carotid ligation without subsequent neurologic sequelae.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Captopril-enhanced 99Tcm-MAG3 renal scintigraphy in subjects with suspected renovascular hypertension.

This pilot study was undertaken to generate preliminary data on the accuracy of captopril-enhanced renal scintigraphy with a relatively new radiopharmaceutical, 99Tcm-mercaptoacetyltriglycine (99Tcm-MAG3) for detecting significant renal artery stenosis. Truth data was based either on arteriographic or outcome criteria (blood pressure response to therapy). Twenty-seven subjects with suspected renovascular hypertension were studied with baseline and captopril-enhanced 99Tcm-MAG3 renal scintigraphy and renal arteriography. Scan interpretations were expressed as a probability of a significant renal artery stenosis. Scan interpretations were compared with renal arteriographic results, renal vein renin levels, blood pressure values after renal artery repair, and blood pressure control after 4-26 months of clinical follow-up. Using > or = 50% luminal obstruction on arteriography as the reference standard for renal artery stenosis and a high probability scan representing a positive test, the test sensitivity and specificity were 33 and 97%, respectively (using high or indeterminate probability to represent a positive scan, the test sensitivity and specificity were 67 and 83%, respectively). The negative predictive value of a low probability scan for renal artery stenosis was 80%. However, including a measure of renovascular hypertension (blood pressure response to renal artery repair) as the reference standard, the accuracy of the scan improves, with the negative predictive value of a low probability scan for renovascular hypertension increasing to 97%. Scintigraphic results were also positively correlated with renal vein renin values in a statistically significant fashion (two-tailed Fisher exact test statistic = 6.43, P = 0.0219). Captopril-enhanced 99Tcm-MAG3 renal scintigraphy is a moderately accurate technique for detecting renal artery stenosis. More importantly, our preliminary findings suggest that the scintigraphic technique using 99Tcm-MAG3 appears to predict the blood pressure response to renal artery repair in subjects with suspected renovascular hypertension, thereby separating subjects with haemodynamically insignificant renal artery stenosis from those with renovascular hypertension.

Angiography↗
PubMed1994

The effect of a tumour necrosis factor antibody on the regenerative response after partial hepatectomy in rats.

In this study we investigated the effect of tumour necrosis factor (TNF) on the regenerative response after partial hepatectomy. Adult male rats were injected intravenously with an antibody to TNF immediately after partial hepatectomy. Animals were sacrificed at 0, 24, 48, 72 and 96 h postoperatively. Hepatic thymidine kinase (TK) activity, liver weight to body weight (LW/BW) ratio, and mitotic index (MI) were used as indices of hepatic regeneration. The rats treated with TNF-Ab had significantly lower levels of TK activity in the liver at 24 h postoperatively compared to the saline treated animals. Furthermore the peak hepatic TK activity was delayed to 48 h in the rats treated with TNF-Ab. The mitotic indices and LW/BW ratios in the TNF-Ab- and saline-treated animals were similar. These data suggest that TNF potentiates the regenerative response after partial hepatectomy.

Animals↗
PubMed1994

Effects of fludrocortisone on sympathetic nerve activity in humans.

Fludrocortisone reduces plasma norepinephrine in healthy humans, but forearm vascular and pressor responses to norepinephrine are potentiated. The effects of fludrocortisone on sympathetic nerve activity in healthy humans are not known. To investigate these effects we evaluated muscle sympathetic nerve activity, heart rate, and arterial pressure in 11 healthy volunteers during three protocols: (1) before and on day 7 of fludrocortisone (0.4 mg/d) treatment with ad libitum diet (n = 6); (2) before and on day 7 of fludrocortisone (0.4 mg/d) or placebo with a 150 mmol/24 h (mEq/24 h) sodium diet (n = 7); and (3) before and on day 2 of fludrocortisone (0.4 mg/d) or placebo with a 150 mmol/24 h (mEq/24 h) sodium diet (n = 4). Placebo did not alter any parameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Mycobacterial infection in renal transplant recipients.

STUDY OBJECTIVE: To determine the prevalence and presentation of mycobacterial infection as well as the influence on outcome in graft function and patient survival in renal transplant recipients at our institution. DESIGN: A retrospective review of case records of all renal transplant recipients from 1980 to 1992. SETTING: Groote Schuur Hospital, a large teaching hospital and regional tertiary referral center in Cape Town, South Africa. PATIENTS: During the period reviewed, 857 transplants were performed. The records of 487 patients who had remained in Cape Town were examined. RESULTS: There were 22 cases of mycobacterial infection (21 confirmed or presumed Mycobacterium tuberculosis and 1 unidentified Mycobacterium other than tuberculosis). In seven cases, immunosuppression had been intensified within 3 months of diagnosis. The median time from transplantation to diagnosis was 14 months (range, 2 to 74). Chest radiograph findings included consolidation (14), miliary pattern (4), pleural effusion (3), tuberculoma (2), cavitation (2), and hilar lymphadenopathy (1). Diagnosis of tuberculosis was made on sputum smears (eight), pleural biopsy specimen (two), fine-needle aspiration (one), and fiberoptic bronchoscopy in ten cases (brushings, eight; transbronchial biopsy specimen, three). Extrapulmonary tuberculosis (in addition to pulmonary tuberculosis) occurred in five patients (tuberculous meningitis, one; renal tuberculosis, one; and dissemminated infection, four). Five of the seven patients in whom immunosuppression had been intensified had concurrent infections; two of these died and the remainder returned to dialysis within 6 months. All but one patient received three antituberculosis drugs, including rifampin and isoniazid, for between 6 and 18 months. At the end of the period of review, 12 (59 percent) patients were alive, 10 with functioning grafts and 2 receiving dialysis. Four patients died while receiving antituberculosis treatment, but death was only directly related to tuberculosis in one case. CONCLUSIONS: Tuberculosis is an important infection in renal transplant recipients in Cape Town, but disseminated disease is less common than reported elsewhere.

Adult↗
PubMed1994

Diagnosis of recurrent brain tumor: value of 201Tl SPECT vs 18F-fluorodeoxyglucose PET.

OBJECTIVE: This prospective study was designed to compare the sensitivity and specificity of a relatively simple examination, 201Tl chloride single-photon emission CT (SPECT), with a more complex examination, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), in patients thought to have recurrent brain tumor. Because both agents have been shown to be markers of viable tumor, we hypothesized that their sensitivity and specificity should be the same. SUBJECTS AND METHODS: Nineteen patients with evidence of recurrent tumor on CT or MR images were studied with both 201Tl SPECT and FDG PET imaging. Two patients were examined twice, so a total of 21 studies were evaluated. The 201Tl SPECT and FDG PET examinations were performed on the same day in 17 patients, and the remaining four examinations were done within 1 week of one another. Three reviewers independently interpreted each Tl SPECT and PET scan. Inappropriate regional increases in 201Tl or FDG activity were considered indicative of tumor recurrence. Sensitivity and specificity values were based on biopsy results and clinical follow-up. The final diagnosis was tumor recurrence in 16 cases and radiation necrosis in 5 cases. The relationship of scan results to survival was analyzed. RESULTS: The sensitivity and specificity of the 201Tl examination for detecting tumor recurrence were 11 (69%) of 16 and two (40%) of five, respectively; values for the FDG PET examination were 13 (81%) of 16 and 2 (40%) of 5, respectively. In patients with recurrent tumors less than 1.6 cm in size, results were false-negative in four 201Tl SPECT examinations and three FDG PET studies. All tumor lesions 1.6 cm or larger (n = 8) were detected. Agreement among the three nuclear medicine specialists was complete for each of the 201Tl SPECT scans. There was disagreement on the interpretation of five (24%) of the 21 FDG PET scans, which was resolved by consensus. Scintigraphic findings did not correlate with patients' survival times. CONCLUSION: We were unable to detect a statistically significant difference in sensitivity or specificity between the 201Tl SPECT and FDG PET scans. Both techniques were sensitive for tumor recurrence with lesions less than 1.6 cm or larger. However, given the greater availability, simplicity, and ease of interpretation and the lower cost of the 201Tl SPECT studies, this technique should be considered for detection of tumor recurrence with lesions that are demonstrated to be 1.6 cm or larger on CT or MR examinations.

Adult↗
PubMed1994

Radiolabeled antibody imaging of patients with potentially resectable colorectal adenocarcinoma.

Thirty-two patients with potentially resectable recurrent colorectal adenocarcinoma were imaged with the radioimmunoconjugate 111In-satumomab pendetide to determine whether imaging supplies clinically relevant information relating to the extent of disease in patients with different presenting characteristics. Patients included 12 with increasing carcinoembryonic antigen (CEA) without anatomical evidence of recurrence, 13 with radiological abnormalities consistent with apparently isolated metastases, and 7 with recurrence and anatomical abnormalities of unclear significance. 111In-satumomab pendetide imaging detected extrahepatic abdominal and pelvic disease in 16 subjects. Imaging was most informative in patients with recurrent disease and anatomical abnormalities of unclear significance, but imaging of the liver was suboptimal owing to high levels of nonspecific uptake. We conclude 111In-satumomab pendetide imaging can supply clinically relevant information relating to the extent and location of recurrent colorectal adenocarcinoma in patients with extrahepatic abdominal and pelvic radiological abnormalities of unclear significance and in radiologically normal patients with high CEA levels.

Adult↗
PubMed1994

The first 100 kidney transplants from living related donors at Groote Schuur Hospital.

Improved results with cadaver kidney transplantation and the increase in the number of cadaver organs have caused the continued use of donor kidneys from living relatives to be questioned. In this analysis of our first 100 renal transplants involving a living related donor, the 5-year graft survival rate was 70%. The 5-year graft survival rate for recipients of grafts from HLA-identical donors was 81%, as opposed to the 64% survival rate for grafts from one-haplotype donors. Recipients of grafts from one-haplotype-matched donors who received donor-specific blood transfusions demonstrated better graft survival than those who were not transfused. This analysis demonstrates that the results of living related kidney transplantation are good, and suggests that donor-specific blood transfusions may be beneficial.

Graft Survival↗
PubMed1994

Ultrasonographic growth and Doppler hemodynamic evaluation of fetuses of obese women.

All fetuses benefit from ultrasonographic estimation of gestational age and evaluation of growth patterns. Monitoring the pregnancies of obese women is perceived as more difficult than monitoring those of nonobese women. The aim of this study was to determine if maternal obesity affects the growth and Doppler resistance indices (RI) of the fetus. Twenty-eight women with a preconception weight > 90.7 kg underwent obstetric ultrasonographic evaluations from the 20th week of gestation. Their ultrasonographic data were compared with those of controls. Ten of the obese women developed gestational diabetes and had lower umbilical artery RIs for a given gestational age (P < .0001) than did those obese women without other medical complications, those with medically controlled pregnancy-induced hypertension or those from the control population. The relation between fetal unit weight and umbilical artery RIs was established. The pattern of RI changes was similar in all groups when estimated fetal weight instead of gestational age was used as the covariant. Fetal growth and Doppler velocimetry can be monitored adequately in obese women. Gestational diabetes significantly influences the pattern of fetal growth and the impedance to flow in the umbilical artery.

Adult↗
PubMed1994

Placement of a double lumen silastic catheter for hemodialysis access through the cephalic vein.

The cephalic vein within the deltopectoral groove provides adequate access to the central venous system for the PermCath hemodialysis catheter. Unlike EJV techniques, which are successful in few instances, the cephalic vein approach was successful in approximately 75 percent of instances. In addition, the rate of complications secondary to bleeding or catheter kinking are decreased with the cephalic vein technique as compared with insertion through the EJV or IJV. We conclude that the cephalic vein is a dependable and functional approach to the central venous system for the PermCath hemodialysis catheter.

Adult↗
PubMed1993

Disordered hemostasis in extrahepatic portal hypertension.

To assess the contribution of naturally occurring portal-systemic shunts to the coagulopathy of patients with liver disease, we studied laboratory parameters of hemostasis in 20 adult patients with extrahepatic portal hypertension, secondary to portal vein thrombosis, that had resulted in variceal bleeding. All extrahepatic portal hypertension patients had normal liver function and histological appearance. None had any evidence of preexisting coagulation disorders, and none had bled or undergone sclerotherapy in the 6 mo before study. Age- and gender-matched groups of 20 healthy individuals and 20 stable patients with cirrhosis and portal hypertension who had a history of variceal bleeding served as controls. Both patient groups had thrombocytopenia consistent with hypersplenism and portal hypertension. Prothrombin international normalized ratio (extrahepatic portal hypertension, 1.3 +/- 0.12; cirrhosis, 1.7 +/- 0.2; control, 1.02 +/- 0.06; p < 0.05) and partial thromboplastin time ratios (extrahepatic portal hypertension, 1.12 +/- 0.1; cirrhosis, 1.26 +/- 0.2; controls, 1.01 +/- 0.03; p < 0.05) were significantly prolonged in both patient groups. Extrahepatic portal hypertension and cirrhotic patient groups had significantly increased levels of serum total fibrin(ogen)-related antigen (extrahepatic portal hypertension, 818 +/- 150 ng/ml; cirrhosis, 454 +/- 52 ng/ml; controls, 124 +/- 7.3 ng/ml; p < 0.05), fibrin monomer (extrahepatic portal hypertension, 168.8 +/- 16.9 ng/ml; cirrhosis, 115.6 +/- 11.1 ng/ml; controls, 19.7 +/- 0.4 ng/ml; p < 0.05) and D-dimer (extrahepatic portal hypertension, 118 +/- 9.6 ng/ml; cirrhosis, 129 +/- 10 ng/ml; controls, 53.2 +/- 1.6 ng/ml; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗