Biomedical subjects

I Francis

Publications and source records attributed to I Francis.

At least 37 records · Page 2Linked to original sources

PubMed1994

CT-SPECT fusion plus conjugate views for determining dosimetry in iodine-131-monoclonal antibody therapy of lymphoma patients.

UNLABELLED: A method for performing 131I quantitative SPECT imaging is described which uses the superimposition of markers placed on the skin to accomplish fusion of computed tomography (CT) and SPECT image sets. METHODS: To calculate mean absorbed dose after administration of one of two 131I-labeled monoclonal antibodies (Mabs), the shape of the time-activity curve is measured by daily diagnostic conjugate views, the y-axis of that curve is normalized by a quantitative SPECT measurement (usually intra-therapy), and the tumor mass is deduced from a concurrent CT volume measurement. The method is applied to six B-cell non-Hodgkin's lymphoma patients. RESULTS: For four tumors in three patients treated with the MB1 Mab, a correlation appears to be present between resulting mean absorbed dose and disease response. Including all dosimetric estimates for both antibodies, the range for the specific absorbed dose is within that found by others in treating B-cell lymphoma patients. Excluding a retreated anti-B1 patient, the tumor-specific absorbed dose during anti-B1 therapy is from 1.4 to 1.7 mGy/MBq. For the one anti-B1 patient, where quantitative SPECT and conjugate-view imaging was carried out back to back, the quantitative SPECT-measured activity was somewhat less for the spleen and much less for the tumor than that from conjugate views. CONCLUSION: The quantitative SPECT plus conjugate views method may be of general utility for macro-dosimetry of 131I therapies.

Adult↗

PubMed1993

Cystic hydatid disease: pitfalls in diagnosis in the Middle East endemic area.

Ultrasound (US) and computerized tomography (CT) have made a significant contribution to accurately localizing focal lesions. Such imaging techniques have been found useful in assessing a hydatid aetiology of cystic lesions. However, we present 23 cases which demonstrate that these modalities in isolation are not adequate in diagnosing hydatid cysts, as claimed from this geographic area. Simple, congenital, choledochal and pancreatic pseudocysts were cystic lesions misinterpreted as hydatid cysts, as were infective disorders such as amoebiasis and tuberculosis. The appearance of a lipoma and an ovarian intra-abdominal cystadenoma and an intra-hepatic haematoma were among other conditions that were labelled as hydatid cysts on US/CT. However, in all the cyst/mass lesions that were misdiagnosed, counter-immunoelectrophoresis (CIEP), with an antigen that elicits an arc-5 in immunoelectrophoresis on cellulose acetate membranes as a substrate, did not detect any anti-Echinococcus antibodies in patients' sera. This was in contrast to the classic indirect haemagglutination test which was equivocal in some cases. The CIEP was specific and excluded hydatidosis though such a diagnosis was ventured on US and/or CT. We therefore conclude that a specific and sensitive serological test is mandatory for confirming a preoperative diagnosis of CHD. When surgery is not immediate, a negative serological test such as the CIEP would in addition indicate US or CT-guided aspiration of cyst fluid for cytological evaluation and/or enzyme immunoassay, thereby avoiding the cost and morbidity of laparotomy. Furthermore, chemotherapy is now a viable alternative provided the diagnosis is unequivocal. This may be a prudent protocol before a further decision on management is envisaged.

Adolescent↗

PubMed1991

Clinical significance of the large adrenal mass.

Current clinical teaching indicates that large (greater than 5 cm in diameter) adrenal masses are often malignant. In a retrospective analysis of patients studied between 1977 and 1988 with computed tomography (CT), adrenal scintigraphy, and when available, magnetic resonance imaging (MRI) 45 were found to have adrenal masses greater than 5 cm (range 5-19 cm) in diameter. Thirty were benign (16 phaeochromocytomas, six adrenocortical adenomas, four adrenal cysts, two myelolipomas, an adrenal hematoma and a ganglioneuroma). Of 15 malignant masses, there were seven adrenocortical carcinomas, five adrenal metastases and three adrenal lymphomas. With the exception of the adrenal myelolipomas, cysts, and the ganglioneuroma neither CT nor MRI demonstrated sufficient diagnostic specificity to distinguish benign from malignant lesions. Functional scintigraphy with 131I-6-beta-iodomethyl-19-norcholesterol for suspected adrenocortical lesions and 131I-metaiodobenzylguanidine for suspected phaeochromocytomas frequently provided useful information.

19-Iodocholesterol↗

PubMed1991

Computed tomography as an adjunct to ultrasound in the diagnosis of acute acalculous cholecystitis.

The sonographic and computed tomographic (CT) findings were reviewed in 17 patients with acute acalculous cholecystitis (AAC) over a 6-year period from 1984 to 1989. Of the six patients in whom both ultrasound and CT were performed, CT revealed marked gallbladder (GB) wall abnormalities, including perforation, and pericholecystic fluid collections in five patients not demonstrated by sonography. Of the total group, five patients had GB wall thicknesses of less than or equal to 3 mm (normal) at pathologic examination, which demonstrated a spectrum of disease ranging from acute hemorrhagic/necrotizing, to gangrenous acalculous cholecystitis with perforation. Sonography was falsely negative or significantly underestimated the severity of AAC in seven of the 13 patients examined by sonography. CT because of its superior ability to assess pericholecystic inflammation may provide additional diagnostic information even after a thorough sonographic study in cases of AAC.

Acute Disease↗

PubMed1991

Clinical significance of the solitary functioning adrenal gland.

To assess the compensatory functional and anatomic changes in the remaining adrenal cortex after unilateral adrenalectomy or in the unaffected adrenal in patients with unilateral adrenal destruction by neoplasm, 17 patients with a single, functioning adrenal gland and normal indices of adrenocortical function, nine after adrenalectomy and eight with a unilateral, destructive adrenal lesion were studied with 131I-6 beta-iodomethyl-19-norcholesterol (NP-59) scintigraphy and computed tomography. Adrenal masses with a mean (+/- s.d.) diameter of 2.8 +/- 1.0 cm; (range 1-4 cm; 95% confidence interval (Cl), 2.5-3.1 cm) were identified by computed tomography in seven of nine patients in the remaining adrenal cortex at variable times (6.1 +/- 5.9 y; range 0.5-19 y) after unilateral adrenalectomy. Mean (+/- s.e.m.) NP-59 uptake was elevated (p less than 0.01) in both adrenalectomy and adrenal destruction groups, mean uptake (+/- s.e.m.) was 0.32% +/- 0.04% administered dose (95% Cl, 0.24%-0.4% administered dose) as compared to normal (0.16% +/- 0.05% administered dose, 95% Cl, 0.06%-0.26% administered dose). The remaining adrenal cortex may be anatomically abnormal after unilateral adrenalectomy and demonstrate compensatory, increased NP-59 uptake in the presence of overall, normal adrenocortical function.

Adosterol↗

PubMed1990

Magnification angiography and histology for the evaluation of microvascular anastomosis.

Magnification angiography was compared with histology in order to assess the value of each of the two techniques for the evaluation of microvascular anastomoses. At postmortem, angiography of 108 end-to-end anastomoses of the rat carotid artery (4.5 X magnification) was performed, followed by histological examination. Each method assessed the degree of stenosis or aneurysmal dilatation independently, expressing it as a percentage of lumen change compared to a noninvolved vessel segment of the same artery. Results were plotted for each carotid separately. Both methods were found to be equally useful, but were of rather low sensitivity and specificity. Each failed to diagnose roughly one-third of all stenoses and even more aneurysms. A possibility for further improvement of the results is discussed. Both methods proved to be complementary; at least one-third of the vascular changes would have been missed if only one method had been used. A combination of both techniques should therefore be used in studies of microvascular anastomoses.

Anastomosis, Surgical↗

PubMed1990

A comparative study of the use of 9-0 PDS and 9-0 prolene in microvascular anastomosis.

9-0 absorbable polydioxanone (PDS) has been compared to 9-0 nonabsorbable Prolene in order to evaluate any advantages of either suture in microvascular surgery. In each of 29 rats, one carotid artery was anastomosed end-to-end with PDS and the other with Prolene. Specimens were harvested 48 hr, 14 days, and three, and five months postoperatively. Histologic examination of the carotids followed postmortem using 4.5 x magnification angiography. Histologic analysis of inflammation, fibrosis, and medical necrosis of the anastomoses revealed no significant differences between the two materials. There was no difference as regards stenosis and aneurysm formation, when evaluated independently by the two methods. It was observed that saccular aneurysms formed as a result of medial necrosis and could develop at any time. Fusiform aneurysms formed where the media was replaced by bulging fibrosis and they appeared late. External support of adherent skeletal muscle prevented aneurysm formation. It can be concluded that the amount of inflammation and fibrosis leading to stenosis is related to the amount of trauma at the time of surgery and not to the type of suturing material used.

Anastomosis, Surgical↗

PubMed1990

Angiogenic activity of normal and pathologic human thyroid tissue.

Thyroid tissue was collected from 60 patients during operations for various thyroid conditions. The tissue's angiogenic capacity was assessed in a chick chorioallantoic membrane preparation. Angiogenic activity was observed in 22 (85%) of 26 solitary follicular neoplasms, in none of ten papillary carcinomas and in one of seven glands with Graves' disease (all pretreated with propranolol). Of 17 glands with euthyroid multinodular colloid goitre, three (18%) showed angiogenic activity. No angiogenic activity was detected in normal thyroid tissue from 26 patients. Angiogenic activity of diseased human thyroid does not seem to be a marker of thyroid malignancy.

Adult↗

PubMed1989

Transient primary hypothyroidism in the newborn: experience of the Victorian Neonatal Thyroid Screening Programme.

Between May 1977 and December 1986, the Victorian Thyroid Screening Programme tested approximately 570,000 newborns for congenital hypothyroidism. One hundred and sixty-six cases of primary hypothyroidism, confirmed by formal thyroid function tests, were identified, of which 24 were later found to be transient. In addition, there were two patients with permanent dyshormonogenesis who passed through a stage of being biochemically euthyroid and so could have been diagnosed mistakenly as transient hypothyroidism. Fourteen of the transient cases were due to excessive intake of iodine. In two, this was due to maternal ingestion of iodide during pregnancy and in 12 the babies received large amounts of topical iodine antiseptic. Two cases were caused by maternal anti-thyroid antibodies and in eight instances the cause was unknown. The large number of cases due to the topical application of iodine antiseptic emphasizes the need for caution when using this substance in neonates.

Female↗

PubMed1988

Diagnosis of cystic hydatid disease: role of aspiration cytology.

Fine needle aspiration of mass lesions is reported in eleven patients in whom cystic hydatid disease (CHD) was not a differential diagnosis or whose serological results were negative. Aspiration was continued until no more fluid could be obtained. In five patients aspiration was done under ultrasound guidance. No sequelae were observed that could be attributed to aspiration per se. Aspirated fluid was stained with haematoxylin and eosin and giemsa or was passed through 5 micron polycarbonate filters which were then stained in the same way. The aspirated material and polycarbonate filters were also stained with trichrome which proved the best stain to demonstrate the acid-fast hooklets. Such filtration of the total volume of the aspirated material or that evacuated at operation is simple, quick, and accurate.

Adult↗

PubMed1988

Thyroid function in very preterm infants.

Indices of thyroid function were measured in 108 infants born at 23-31 weeks gestation, after birth, at 24 and 72 h, and at 1, 3, 4, 5 and 6 weeks of age. This group was characterised by low serum thyroxine (T4), normal thyroid stimulating hormone (TSH), low-normal thyroid binding globulin (TBG), low free thyroxine index (FTI) and low triiodothyronine (T3). The incidence of hypothyroxinaemia defined as a serum T4 value of less than 65 nmol/l was 58% after birth, increasing to 84% at 1 week, after which there was progressive reduction to 36% by 6 weeks of age. Mean T4 values were inversely proportional to gestational age during this study period. Infants of 23-28 weeks gestation had significantly lower T4, TBG, FTI and T3 values compared to those of 29-31 weeks gestation. Infants who had hyaline membrane disease (HMD) had significantly lower T4 and FTI values compared to those without HMD for up to 3 weeks of age. Similar differences were found between deaths and survivors in the first week after birth. This study suggests that there is increasing delay in maturation of the hypothalamic-pituitary-thyroid axis control with increasing prematurity. In addition, the data suggest that infants who were extremely preterm or those with HMD had worse and more persistent abnormalities of thyroid function secondary to their illness and metabolic stress. The significance of our findings, in particular that of prolonged hypothyroxinaemia, is uncertain. The role of thyroid replacement therapy in these very preterm infants therefore need to be assessed with a randomised clinical trial.

Age Factors↗

PubMed1988

Intermittent intra-aortic balloon tamponade during hemorrhagic shock.

The use of intermittent intra-aortic balloon tamponade was evaluated during resuscitation of hemorrhagic shock in a sheep model. Twenty adult sheep were exposed to severe hemorrhagic shock and they were all treated with crystalloids (8% of body wt) during one hour. Ten of these were also treated with intermittent supraceliac intra-aortic balloon tamponade during the initial 30 min (group A) while the other 10 were used as a controls (group B). In the group treated with intra-aortic tamponade the mean arterial pressure (MAP) was rapidly increased as the balloon was inflated, but it dropped to the same level as in the control group during deflation. In this group there were also great fluctuations in systemic vascular resistance (SVR), pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) when the aortic balloon was inflated/deflated, while central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) were hardly affected at all. After final deflation of the aortic balloon (at 30 min), MAP remained 35% lower than the baseline value (p less than 0.01), similar to the control group. Cardiac index (CI) increased continuously during the first 30 min, at which time it reached the pre-shock level in both groups. At the end of the resuscitation period there was no significant difference between the two groups in any of the cardiovascular parameters measured. Four animals died in group A and 3 in group B within 24 hours, after which time the survivers were sacrificed. Both groups had high incidence of pathological changes in the kidneys, liver, intestine, and lungs. Six animals in group A had hind limb paralysis and loss of anal sphinter tone after the resuscitation. It was concluded that intermittent supraceliac aortic occlusion for 30 minutes did not decrease morbidity or mortality in sheep exposed to severe hemorrhagic shock compared with a control group treated in a traditional way with fluid replacement.

Animals↗

PubMed1988

Intraaortic balloon tamponade during hemorrhagic shock in sheep.

Two groups (n = 10 in each) of adult sheep were exposed to hemorrhagic shock resulting in mean arterial pressure (MAP) below 25 mmHg for 10 min. Following that, group A received crystalloids (8% of body wt) during one hr together with supraceliac intraaortic balloon tamponade during the first 30 min, while group B (controls) received crystalloids only. The central circulation was rapidly restored in group A, as indicated by increased MAP and increased systemic vascular resistance (SVR). After deflation of the balloon MAP dropped to the same value as in the control group, while cardiac index increased gradually with volume replacement and was significantly higher at the end of the resuscitation period (60 min) than in the control group (P less than 0.05). Despite a more rapid restoration of central hemodynamics in group A, lactic acidosis was more severe, acute renal failure and neurological complications more frequent, and mortality higher than in the control group. It was concluded that continuous supraceliac aortic occlusion for 30 min had deleterious effects on organs dependent on aortic blood flow distal to the aortic tamponade and may contribute to the development of multiple organ failure after resuscitation from hemorrhagic shock. Further studies are needed to evaluate the effects of intermittent intraaortic balloon tamponade in hemorrhagic shock.

Animals↗

PubMed1987

Biliary obstruction secondary to an extramedullary plasmacytoma of the pancreas: confusion with pancreatitis on computed tomography.

A 29-year-old woman with a history of a maxillary plasmacytoma treated with radiation therapy presented with painless jaundice. A computed tomography (CT) scan revealed biliary dilatation and diffuse pancreatic enlargement suggestive of pancreatitis. Percutaneous transhepatic cholangiography demonstrated encasement of the distal common bile duct by an extrinsic mass. At exploratory laparotomy, a large mass replacing the entire pancreas was found. Pathologic examination confirmed plasmacytoma. This report presents a unique case of extramedullary plasmacytoma involving the pancreas early in a patient's clinical course. The CT appearance was similar to that of acute pancreatitis.

Adult↗

PubMed1985

Surgical treatment of cardiac pheochromocytomas.

The development at our institution of the radiopharmaceutical 131-I-metaiodobenzylguanidine has permitted for the first time scintigraphic localization of pheochromocytomas. By the use of this scan in combination with contrast-enhanced computed tomography, intrapericardial pheochromocytomas have been demonstrated in eight patients at our hospital during the past 2 years. Four of these patients have been operated upon by us, and each was found to have a pheochromocytoma arising from the heart (left atrium in three and interventricular groove at the aortic root in one). While in one patient it was possible to "shell" the tumor away from the left atrial wall without cardiopulmonary bypass, in the remaining patients, bypass and cardioplegia were required to resect the pheochromocytomas without inducing life-threatening intraoperative hypertension and cardiac arrhythmias. One patient required coronary artery reconstruction and two, excision of the posterior left atrial wall with pericardial replacement. One of these latter two patients died intraoperatively of uncontrollable hemorrhage. The three remaining patients are well and normotensive after more than 1 year of follow-up. Cardiac pheochromocytomas should not be approached as typical posterior mediastinal tumors, or as they are in the abdomen, with the expectation that they will "shell away" from contiguous structures. Cardiopulmonary bypass should be available, and resection of involved myocardium may be necessary for complete removal.

3-Iodobenzylguanidine↗

PubMed1984

The location of middle mediastinal pheochromocytomas.

Eight middle mediastinal pheochromocytomas were located by means of 131I- meta- iodobenzylguanidine scintigraphy. The exact anatomic location of the lesions was confirmed by means of dynamic computed tomographic scanning following bolus injection of contrast medium. In all but one case the lesion had not been detected prior to scintigraphy despite extensive investigations including arteriography, venography with sampling, computed tomography with infusion of contrast medium, and in some cases surgical exploration of the abdomen and chest. Accurate anatomic location of the lesion permitted resection of five lesions from the cardiac atria and one from the aortopulmonary window. A sixth case in which an atrial pheochromocytoma was found by coronary angiography was not cured by resection of the primary tumor, and 131I- meta- iodobenzylguanidine scintigraphy revealed extensive metastases. Thus 131I- meta- iodobenzylguanidine scintigraphy has been of considerable value in the location of pheochromocytomas of the middle mediastinum, which may be a more frequent site than previously recognized.

3-Iodobenzylguanidine↗

PubMed1983

Genetic screening of newborn in Australia. Results for 1981.

Since screening of newborn infants for phenylketonuria (PKU) by the Guthrie bacterial inhibition assay was established in the 1960s, 3 017 703 infants have been tested in Australia. Two hundred and fifty-one cases of PKU (0.83/10 000) and six cases of the variant forms of malignant hyperphenylalaninaemia (MHPA) (0.02/10 000) have been detected. In 1981, 11 infants with PKU were detected. Screening for congenital hypothyroidism was carried out in seven States, and 66 new cases were detected in 1981 (2.13/10 000). In Adelaide, 154 310 infants have been tested for galactosaemia and a total of seven cases have now been detected (0.45/10 000). In New South Wales, 35 955 infants have been tested for cystic fibrosis of the pancreas, and 17 cases were found (4.73/10 000).

Australia↗

PubMed1982

Genetic screening of newborn in Australia: results for 1980.

Since screening of newborn infants for phenylketonuria (PKU) by Guthrie bacterial inhibition assay was established in the 1960s, 2779 790 infants have been tested in Australia. Two hundred and forty cases of PKU (rate: 1/11 582) and six cases of the variant forms of malignant hyperphenylalaninaemia (MHPA) (rate: 1/463 298) have been detected. In 1980, 18 infants with PKU were detected. Screening for congenital hypothyroidism was carried out in six centres, and 40 new cases were detected in 1980.

Australia↗