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Biomedical subjects

J A Lawrance

Publications and source records attributed to J A Lawrance.

7 recordsLinked to original sources
PubMed2004

Tositumomab and iodine I 131 tositumomab for recurrent indolent and transformed B-cell non-Hodgkin's lymphoma.

PURPOSE: An open-label phase II study was conducted at two centers to establish the efficacy and safety of tositumomab and iodine I 131 tositumomab at first or second recurrence of indolent or transformed indolent B-cell lymphoma. PATIENTS AND METHODS: A single dosimetric dose was followed at 7 to 14 days by the patient-specific administered radioactivity required to deliver a total body dose of 0.75 Gy (reduced to 0.65 Gy for patients with platelets counts of 100 to 149 x 10(9)/L). Forty of 41 patients received both infusions. RESULTS: Thirty-one of 41 patients (76%) responded, with 20 patients (49%) achieving either a complete (CR) or unconfirmed complete remission [CR(u)] and 11 patients (27%) achieving a partial remission. Response rates were similar in both indolent (76%) and transformed disease (71%). The overall median duration of remission was 1.3 years. The median duration of remission has not yet been reached for those patients who achieved a CR or CR(u). Eleven patients continue in CR or CR(u) between 2.6+ and 5.2+ years after therapy. Therapy was well tolerated; hematologic toxicity was the principal adverse event. Grade 3 or 4 anemia, neutropenia, and thrombocytopenia were observed in 5%, 45%, and 32% of patients, respectively. Secondary myelodysplasia has occurred in one patient. Four patients developed human antimouse antibodies after therapy. Five of 38 assessable patients have developed an elevated thyroid-stimulating hormone; treatment with thyroxine has been initiated in one patient. CONCLUSION: High overall and CR rates were observed after a single dose of tositumomab and iodine I 131 tositumomab in this patient group. Toxicity was modest and easily managed.

Adult↗
PubMed1999

Assessment and significance of mediastinal bulk in Hodgkin's disease: comparison between computed tomography and chest radiography.

PURPOSE: In Hodgkin's disease (HD), mediastinal bulk is currently defined from chest radiograph (CXR) measurements as a ratio of the maximum transverse mass diameter to the internal thoracic diameter at T5/6 level > or = 0.33. We evaluated how computed tomographic (CT) measurements of bulk correspond to those obtained from the CXR and correlated nodal mass long axis diameter with freedom from progression. METHODS: Ninety-five adult patients who had a CXR thoracic ratio of greater than 0.3 and a CT scan within 28 days of the CXR were included in the study, provided that both investigations were performed before the start of treatment. Measurements of the widest mediastinal diameter and internal thoracic diameter were made on both CXR and CT scan. The thoracic ratio (TR) was calculated for each modality and compared using paired t tests. The longest diameter of the largest individual nodal mass (LIM(CT)) was also measured from the CT and correlated with freedom from progression using Cox regression. RESULTS: There was excellent correlation between CT and CXR for measurement of TR, with TR(CT) greater than TR(CXR) (mean difference of 2%). A TR(CT) of 0. 35 was found to be equivalent to a TR(CXR) of 0.33. No single measurement of nodal size correlated with the current definition of bulk. However LIM(CT) greater than 10 cm did correlate with increased risk of progressive HD (P =.03), even after adjustment for other prognostic variables (chemotherapy regimen and Hasenclever Prognostic Index). CONCLUSION: Excellent correlation was observed between assessment of TR by CXR and CT scan. The longest diameter of the LIM(CT) greater than 10 cm was found to be associated with an increased risk of disease progression.

Adult↗
PubMed1997

Zebra pattern: a diagnostically challenging hepatic parenchymal enhancement pattern at CT arterial portography.

PURPOSE: To investigate the effect of arterial injection site and splenic volume on the hepatic zebra pattern seen at computed tomographic (CT) arterial portography. MATERIALS AND METHODS: Images from CT arterial portographic examinations, performed via either the splenic artery (SA)(n = 47) or superior mesenteric artery (SMA)(n = 51) in 98 patients, were reviewed. The hepatic parenchymal enhancement pattern was assessed by three blinded reviewers. Splenic volume was determined. RESULTS: Twenty-two of 98 (22%) CT arterial portographic studies showed a zebra pattern: 10 of 47 (21%) with injection via the SA and 12 of 51 (24%) with injection via the SMA. The mean percentage of hepatic parenchyma with nontumorous perfusion defects was 55% with the zebra pattern versus 12% without (P < .001). For SA injections, the mean splenic volume was lower in patients with the zebra patterns (321 vs 409 cm3, P = .09). For SMA injections, it was higher in patients with zebra patterns (372 vs 291 cm3, P = .10). CONCLUSION: The zebra pattern can cause difficulties in interpreting images. It is due to alternating, well-defined regions of portal venous hyper- and hypoperfusion; it likely has a multifactorial cause and is likely due to technical parameters such as the injection site, the volume of the spleen, and the hemodynamic effects of the tumor.

Adult↗
PubMed1996

MRI diagnosis of partial tears of the anterior cruciate ligament.

In an attempt to define the magnetic resonance imaging (MRI) features of partial tears of the anterior cruciate ligament (ACL) we retrospectively analysed the MRI scans of 30 patients with a recent arthroscopic finding of a normal, a partial or a completely torn ACL. On review of the original reports MRI correctly predicted 9/9 (100 per cent) complete ACL tears, 11/12 (92 per cent) normal ACLs but only 1/9 (11 per cent) partial ACL tears. On analysis of the MRI there were four features which helped to differentiate partial ACL tears from either complete ACL tears or normal ligaments. These were the appearance of some intact fibres, thinning of the ligament, a wavy or curved ligament and the presence of an inhomogeneous mass posterolateral to the ACL. We propose that these findings may be indicators of partial ACL tear.

Adolescent↗
PubMed1996

CT during arterial portography: comparison of injection into the splenic versus superior mesenteric artery.

PURPOSE: To determine whether the diagnostic quality of computed tomography (CT) during arterial portography (CTAP) performed via the splenic artery (SA) is better than that performed via the superior mesenteric artery (SMA). MATERIALS AND METHODS: The authors evaluated CTAP images obtained in 98 patients from 1991 to 1994; 47 examinations were performed via the SA and 51 were performed via the SMA. Images were reviewed, by consensus, by three radiologists blinded to catheter location. Hepatic enhancement was quantitatively assessed in 53 patients (31 in the SA group, 22 in the SMA group). RESULTS: The numbers of low-attenuation non-tumor-related perfusion defects (19 in the SA group, 17 in the SMA group), high-attenuation non-tumor-related perfusion defects (six in the SA group, six in the SMA group), diffuse mottled perfusion abnormalities (six in the SA group, five in the SMA group), and portal venous flow defects (20 in the SA group, 20 in the SMA group) were similar in both groups (P > .05). Peak hepatic enhancement was similar in both groups (SMA group = 111 HU; SA group = 112 HU) (P > .05). CONCLUSION: There is no difference in quality between CTAP performed via the SA versus CTAP performed via the SMA.

Adult↗
PubMed1994

Colonic preparation with Picolax: patient tolerance and approaches to fluid replacement.

Sodium picosulphate (Picolax) is widely used for bowel preparation prior to colonic investigation or surgery. The most troublesome side effect reported is headache, which has been thought to be due to dehydration. In a prospective randomized study we investigated the incidence of adverse effects in patients given Picolax prior to barium enema examination, and assessed the incidence of adverse effects with different oral fluid regimens. A total of 197 outpatients were allocated to one of five fluid regimens on the day prior to the enema: (a) 4 pints of Dioralyte (glucose and electrolyte solution); (b) 4 pints of half-strength Dioralyte; (c) 4 pints of water; (d) 6 pints of water; and (e) free fluids. In a questionnaire, 36% of patients had no headache (graded 0/5), while 38% had a significant headache (graded 3/5 or greater). Sixteen per cent had significant abdominal pain, 42% had dry mouths, 43% thirst and 34% tiredness or irritability. There was no correlation between headache and fluid regimen. Furthermore, we have found no evidence of dehydration. None of the five fluid regimens was shown to offer any advantage, and we therefore recommend that patients be allowed to drink according to thirst when taking Picolax.

Abdominal Pain↗