Ammonia and nitrous oxide emissions from two acidic soils of Nova Scotia fertilised with liquid hog manure mixed with or without dicyandiamide

Gaseous nitrogen (N) loss from field-applied manure in the form of ammonia (NH(3)) and nitrous oxide (N(2)O) has negative agronomic, environmental and health implications. This study was undertaken to evaluate the combined effect of soil type and dicyandiamide (DCD) on NH(3) and N(2)O emissions following application of liquid hog manure. Soil samples (100g) were placed in 500 mL screw-top Mason-jars and de-ionised water was added to bring the soil samples to 50%, 70% and 90% water-filled pore space (WFPS). Slurry and slurry+DCD treatments were applied at a rate of 116000 l ha(-1). The jars were then sealed and incubated at 21 degrees C for 21 d. Ammonia volatilisation was quantified using boric acid traps while N(2)O gas concentrations were analysed using gas chromatography. Results showed that DCD had no effect (p>0.05) on either NH(3) or N(2)O emissions. However, soil type had a significant effect (p<0.05) on both gases. Overall, the Pugwash soil produced 3 and 2.5 times more NH(3) and N(2)O, respectively, than the Acadia soil. N(2)O emissions from both soils increased with an increase in %WFPS, indicating that during the spring and fall in Atlantic Canada, when soils are generally wet, a significant amount of N(2)O may be emitted from these soils. The relationship between cumulative N(2)O and %WFPS was best described by an exponential function R(2)=0.83 and p<0.05 (both soils). Therefore, soil type should be taken into consideration when formulating N(2)O emission factors. The addition of DCD together with slurry may not be a viable strategy to mitigate N(2)O emissions from acidic soils. To reduce emissions of both gases, livestock slurry should not be applied on wet soils.

Expression of KIT and epidermal growth factor receptor in chemotherapy refractory non-seminomatous germ-cell tumors

BACKGROUND

The majority of patients with germ-cell tumors (GCTs) are curable with standard therapy. The molecular differences between curable and incurable disease are unknown. We have studied the expression of KIT and the epidermal growth factor receptor (EGFR) to determine their incidence in chemorefractory disease.

PATIENTS AND METHODS

We retrospectively analyzed 23 patients with chemorefractory non-seminomatous GCTs (15 late relapse and eight transformed teratomas). None of these 23 patients were cured by their initial chemotherapy and/or surgery. Immunohistochemical analysis of KIT and EGFR was performed on the most recently available specimen from a metastatic site. PCR amplimers of KIT exon 17 were screened for mutations by a combination of denaturing high-performance liquid chromatography and direct sequencing.

RESULTS

KIT was expressed (>/=10% of the tumor displaying membranous or cytoplasmic staining) in 11 of 23 GCT patients [48%; 95% confidence interval (CI) 26% to 68%]. There were no activating KIT mutations in the phosphoryltransferase domain (exon 17) in 21 patients analyzed. EGFR was expressed (1+ to 3+) in 15 of 23 GCT patients (65%; 95% CI 41% to 82%).

CONCLUSIONS

KIT and EGFR are expressed in a significant proportion of refractory GCTs. The significance of these findings will be determined by ongoing clinical trials.

[The medical imaging and radiology department]

Technological developments arising from research have affected the whole wide spectrum of medical endeavor and have made a very significant impact on clinical practice and especially on imaging sciences. Ultrasonography brought spectacular advances, but CT and MRI became important landmark techniques. A further important development, which greatly increased the involvement of radiologists in direct patient management, was the growth of interventional and therapeutic techniques, called interventional radiology. Some statistics: approximately 155,000 patients per year including 19,000 CT Scans, 10,000 MRI exams, 21,000 ultrasound examinations and 1,000 therapeutic procedures. Some research activities: CT quantification of pulmonary emphysema, respiratory mechanics, MR and CT angiography, antenatal diagnosis of congenital and genetic diseases of the fetus, quantification of portal haemodynamics, MR imaging of bile and pancreatic ducts, morphologic and functional imaging of the brain, radiology of bone trauma, MR characterization in hepatic lesions.

Quantitative computed tomography assessment of lung structure and function in pulmonary emphysema

Accurate diagnosis and quantification of pulmonary emphysema during life is important to understand the natural history of the disease, to assess the extent of the disease, and to evaluate and follow-up therapeutic interventions. Since pulmonary emphysema is defined through pathological criteria, new methods of diagnosis and quantification should be validated by comparisons against histological references. Recent studies have addressed the capability of computed tomography (CT) to quantify pulmonary emphysema accurately. The studies reviewed in this article have been based on CT scans obtained after deep inspiration or expiration, on subjective visual grading and on objective measurements of attenuation values. Especially dedicated software was used for this purpose, which provided numerical data, on both two- and three-dimensional approaches, and compared CT data with pulmonary function tests. More recently, fractal and textural analyses were applied to computed tomography scans to assess the presence, the extent, and the types of emphysema. Quantitative computed tomography has already been used in patient selection for surgical treatment of pulmonary emphysema and in pharmacotherapeutical trials. However, despite numerous and extensive studies, this technique has not yet been standardized and important questions about how best to use computed tomography for the quantification of pulmonary emphysema are still unsolved.

The vacuum phenomenon: a CT sign of nonunited fracture

OBJECTIVE

The purpose of this study was to describe on CT scans the presence of a gas collection within a bone fracture reflecting the vacuum phenomenon as a sign of nonunited fracture.

CONCLUSION

A gas collection between fractured bone fragments suggests a nonunited fracture.

Balloon angioplasty of native coarctation of the aorta in infants and neonates: is it worth the hassle?

Balloon angioplasty (BA) for native coarctation of the aorta (CA) in infants and neonates remains controversial with a high incidence of restenosis. The purpose of this study is to analyze our acute and midterm results for BA of native CA in infants and neonates and try to identify factors that may be predictive of outcome. Between September 1991 and June 1999, 17 patients with CA underwent BA at a median age of 3 months (range 2 weeks--9 months) and median weight of 4.8 kg (range 2.8--7 kg). Fourteen patients had discrete CA and 3 had tubular hypoplasia. All patients were hemodynamically stable prior to BA and no patients had critical coarctation requiring prostaglandin E(1) infusion to maintain ductus arteriosus patency. Seven patients had other associated cardiac defects. All patients had significant initial improvement. The mean peak systolic gradient across the CA improved from 43 +/- 15 mmHg to 10 +/- 8 mmHg (p < 0.001), and the mean minimum diameter of the aortic lumen increased from 2.4 +/- 0.9 mm to 5.2 +/- 1.0 mm (p < 0.001). There was no mortality or major complication. At median follow-up interval of 2.7 years (0.15-7.75 years), 10 (59%) of 17 patients are clinically well and have an upper to lower limb systolic blood pressure difference of <20 mmHg. Seven (41%) of 17 patients developed significant restenosis (5 of these patients underwent repeat BA, which was successful in 3 patients). Four (24%) patients underwent surgical repair at a median age of 4.5 months (3--6.9 months) and a median time interval of 4 months (2--6.5 months) from the initial BA. All 3 patients with tubular hypoplasia type of CA underwent surgical repair. No patients developed aortic aneurysm following initial or repeat BA. All patients who underwent surgical repair were 1 month or less in age at the time of their initial BA. We conclude that BA of native CA in infants and neonates can be performed safely with low mortality and morbidity. It appears to offer the best results in patients who are older than 1 month with discrete CA and a well-developed aortic arch. Further restenosis of the discrete CA can be managed successfully by repeat BA.

[Multifocal osteosarcoma. A case report]

Multifocal osteosarcoma is an uncommon and aggressive presentation of osteosarcoma.

CASE REPORT

We report a case of multifocal osteosarcoma in a 12-year-old boy who was admitted for a tumor of the skull, associated with pleural and pulmonary nodules. A computed tomography scan of the head showed a calcified lesion with intra- and extracranial extent. A biopsy of the skull tumor showed an osteoblastic osteosarcoma. Three weeks later, the patient developed two other tumors of the skull, a tumor of the left shoulder and a pelvic pain. Radiographic studies confirmed the presence of further lytic lesions at these sites. The patient was unresponsive to chemotherapy (high dose methotrexate and doxorubicin) and died nine months later.

COMMENTS

Multifocal osteosarcoma, or osteosarcomatosis, is a highly aggressive form of osteosarcoma. The multiple lesions can all arise synchronously as primary tumors, or appear to be one dominant site with early and rapid appearance of secondary lesions. The incidence is reported to be between 1 and 10% of osteosarcoma. The histology shows an osteosarcoma of osteoblastic type in most cases.

CONCLUSION

Despite intensive chemotherapy, the prognosis remains poor. The debate remains as to whether or not this clinical presentation represents true multifocality of the disease or a relatively unusual metastatic pattern of osteosarcoma.

Peri-optic nerve infiltration during leukaemic relapse: MRI diagnosis

BACKGROUND

A 10-year-old boy with a history of acute lymphoblastic leukaemia (ALL), but without previous evidence of central nervous system involvement, presented with seizures 3 years after complete remission.

MATERIALS AND METHODS

MRI showed bilateral enlargement of the optic nerves despite normal ophthalmological examination.

RESULTS

Only the third cerebrospinal fluid examination showed 2 % blasts without concomitant bone-marrow infiltration. Enlargement of the optic nerves was consistent with bilateral leukaemic peri-optic nerve infiltration. The appearances returned to normal after chemotherapy.

CONCLUSION

The optic nerves are a potential site of relapse in patients with systemic and meningeal ALL, even in the absence of ophthalmological signs.

Transcatheter closure of a large coronary arteriovenous fistula using the new Amplatzer Duct Occluder

A 9-year-old patient with a large coronary arteriovenous fistula (circumflex-right atrium) underwent successful complete percutaneous closure, using the new Amplatzer Duct Occluder (ADO) inserted via a 6 Fr sheath.

Transgenic mice for MTCP1 develop T-cell prolymphocytic leukemia

T-cell prolymphocytic leukemia (T-PLL) is a rare form of mature T-cell leukemia associated with chromosomal rearrangements implicating MTCP1 or TCL1 genes. These genes encode two homologous proteins, p13(MTCP1) and p14(TCL1), which share no similarity with other known protein. To determine the oncogenic role of MTCP1, mice transgenic for MTCP1 under the control of CD2 regulatory regions (CD2-p13 mice) were generated. No abnormality was detected during the first year after birth. A late effect of the transgene was searched for in a cohort of 48 CD2-p13 mice aged 15 to 20 months, issued from 3 independent founders. Lymphoid hemopathies, occurring in the three transgenic lines, were characterized by lymphoid cells with an irregular nucleus, a unique and prominent nucleolus, condensed chromatin, a basophilic cytoplasm devoid of granules, and an immunophenotype of mature T cells. The molecular characterization of Tcrb rearrangements demonstrated the monoclonal origin of these populations. Histopathological analysis of the cohort demonstrated early splenic and hepatic infiltrations, whereas lymphocytosis and medullar infiltrations were found infrequently. The engraftment of these proliferations in H2-matched animals demonstrated their malignant nature. Cumulative incidence of the disease at 20 months was 100%, 50%, and 21% in F3, F4, and F7 lines, respectively, and null in the control group. The level of expression of the transgene, as estimated by Western blotting in the transgenic lines correlated with the tumoral incidence, with the highest expression of p13(MTCP1) being found in F3 mice. CD2-p13 transgenic mice developed an hemopathy similar to human T-PLL. These data demonstrate that p13(MTCP1) is an oncoprotein and that CD2-p13 transgenic mice represent the first animal model for mature T-PLL.

Asbestosis, pleural plaques and diffuse pleural thickening: three distinct benign responses to asbestos exposure

The aim of this study was to investigate by computed tomography (CT) whether asbestosis, diffuse pleural thickening and/or pleural plaques are statistically associated. We also tried to find criteria to differentiate between diffuse and circumscribed pleural thickening. From 231 exposed workers, only those subjects whose radiograph showed neither bilateral calcified pleural plaques nor small pulmonary opacities higher than 1/1 grade according to the 1980 International Labour Office (ILO) Classification were considered. Scans were assessed for the presence of subpleural curvilinear lines, septal and intralobular lines, parenchymal bands, honeycombing, rounded atelectasis, pleural plaques and diffuse pleural thickening. CT scans revealed pleural and/or lung abnormalities in 99 workers. Pleural plaques were unilateral in one-third of cases with plaques. Diffuse pleural thickening, parenchymal bands and rounded atelectasis were unilateral in, respectively, 62 and 69 and 75% of cases with the abnormality. Septal and intralobular lines, and honeycombing were always bilateral. CT signs could be grouped into three patterns: 1) septal and intralobular lines, and honeycombing corresponding to pulmonary fibrosis; 2) pleural plaques corresponding to parietal pleural fibrosis; and 3) diffuse pleural thickening, rounded atelectasis and parenchymal bands corresponding to visceral pleural fibrosis. In these workers with a normal or near-normal radiograph, three groups of subjects with different responses were distinguished. Crow's feet and rounded atelectasis help to differentiate plaques from diffuse thickening.

Transcatheter closure of secundum atrial septal defect in a patient with dextrocardia using the amplatzer septal occluder

Transcatheter closure of secundum atrial septal defects (ASD) in patients with levocardia is performed routinely using various investigational devices. A 6-yr-old child with dextrocardia, situs inversus, and secundum ASD measuring 13 mm by TEE underwent successful transcatheter closure using a 15 mm Amplatzer Septal Occluder with complete closure of the defect.

Alternative origin of p13MTCP1-encoding transcripts in mature T-cell proliferations with t(X;14) translocations

The MTCP1 gene is involved in the t(X;14)(q28;q11) translocation associated with T-cell prolymphocytic leukemia and related conditions. This gene is unusual in that it codes for two distinct proteins: a small mitochondrial protein, p8MTCP1, and a putative oncogenic protein, p13MTCP1. Scarcity of material from t(X;14)-associated proliferations and very low levels of mRNA expression have so far prevented a thorough description of p13MTCP1-encoding transcripts. Here, we characterize two additional t(X;14) bearing leukemias allowing this analysis. In one case, with a breakpoint located 5' to the MTCP1 gene, the level of transcription of previously described p13MTCP1-encoding transcripts is enhanced. In the second case, with a breakpoint within the MTCP1 intron I, an alternative transcription initiation site is demonstrated in the tumor cells at 229 bp upstream to exon II. The identification of this internal promoter, together with the similarity between TCL1 and MTCP1 genomic structures, allow us to propose a model in which the duplication of an ancestral gene was followed by the insertion of one copy within the intron of a p8-encoding gene, accounting for the unusual feature of the MTCP1 gene.

Endovascular aortic stent-grafts: transcatheter embolization of persistent perigraft leaks

PURPOSE

To assess efficacy of transcatheter embolization of peri prosthetic leaks from aortic stent-grafts

MATERIALS AND METHODS

Eight patients with a long-standing (3-13 months) perigraft leak after stent-graft implantation underwent transcatheter embolization. Leakage was demonstrated at helical computed tomography (CT). Angiography was performed for evaluation of outflow vessels and transcatheter embolization. All patients underwent helical CT follow-up after the procedure and every 3 months.

RESULTS

Embolization was successful in seven patients and resulted in aneurysmal sac thrombosis. A second procedure was necessary in one patient to complete occlusion of the aneurysm. No further aneurysmal growth was detected during 4-9 months follow-up. Right leg paresis was observed in one patient immediately after the procedure, but symptoms disappeared completely after 8 days. Another patient had a minor sensory deficit in the region of the right crural nerve.

CONCLUSION

Transcatheter embolization of perigraft leaks appears to be an effective technique to achieve aneurysmal thrombosis.

[Emergency treatment of hemobilia using embolization]

Embolotherapy has gained widespread acceptance as the modality of choice for the management of hemobilia because of its safety profile. Our case reports a successful transcatheter embolization of the right hepatic artery aneurysm causing hemobilia in a patient in hemodynamic instability.

TEL-AML1 fusion RNA as a new target to detect minimal residual disease in pediatric B-cell precursor acute lymphoblastic leukemia

It has recently been shown that the t(12;21)(p13;q22) translocation fuses two genes, TEL on chromosome 12 and AML1 on chromosome 21. We have evaluated the frequency of this newly described translocation in acute lymphoblastic leukemia (ALL), and the feasibility of minimal residual disease (MRD) monitoring by polymerase chain reaction (PCR) amplification of TEL-AML1 transcripts. Thirty-nine adult- and 45 childhood-ALLs consecutively diagnosed in a single center were included in this study. TEL-AML1 fusion transcripts were searched for in the 39 adult- and 45 childhood-ALLs for which material was available. BCR-ABL, E2A-PBX1, and MLL-AF4 transcripts were also studied by PCR in these cases. TEL-AML1 transcripts were found in 8 out of 35 (23%) childhood B-cell precursor ALLs (BCP-ALLs). TEL-AML1 transcripts were detected in only 1 of 31 adult BCP-ALLs (P = .04, Fisher's exact test). Nevertheless, in this adult case, TEL-AML1 transcripts were found at a low level in 2 of 3 different samples. BCR-ABL, E2A-PBX1, and MLL-AF4 transcripts were found in 12, 3, and 1 cases of 31 adult BCP-ALLs, and in 1, 2, and 1 cases of 35 childhood BCP-ALLs, respectively. TEL-AML1 transcripts were never found associated with any other fusion transcripts. Taken together, the four types of chimeric transcripts were detected in 12 of 35 (34%) childhood BCP-ALL cases. No TEL-AML1 transcripts were detected in 11 T-cell ALLs (4 adults and 5 children), nor in 2 B-cell (slg+) ALLs. MRD was evaluated in 21 samples collected in 9 TEL-AML1+ childhood BCP-ALL cases during therapy (median follow-up = 200 days). Of 8 patients evaluated after induction therapy, 4 showed detectable but low levels of MRD. Of 7 patients serially evaluated, only one showed persistence of detectable MRD. This study shows that TEL-AML1 transcripts are frequently detected in pediatric BCP-ALLs and that these transcripts are molecular targets that will simplify the strategy of MRD monitoring in childhood BCP-ALL.

Multiple tumor-suppressor gene 1 inactivation is the most frequent genetic alteration in T-cell acute lymphoblastic leukemia

No constant genetic alteration has yet been unravelled in T-cell acute lymphoblastic leukemia (T-ALL), and, to date, the most frequent alteration, the SIL-TAL1 deletion, is found in approximately 20% of cases. Recently, two genes have been identified, the multiple tumor-suppressor gene 1 (MTS1) and multiple tumor-suppressor gene 2 (MTS2), whose products inhibit cell cycle progression. A characterization of the MTS locus organization allowed to determine the incidence of MTS1 and MTS2 inactivation in T-ALL. MTS1 and MTS2 configurations were determined by Southern blotting using 8 probes in 59 patients with T-ALL (40 children and 19 adults). Biallelic MTS1 inactivation by deletions and/or rearrangements was observed in 45 cases (76%). Monoallelic alterations were found in 6 cases (10%). The second MTS1 allele was studied in the 4 cases with available material. A point mutation was found in 2 cases. The lack of MTS1 mRNA expression was observed by Northern blot analysis in a third case. A normal single-strand conformation polymorphism pattern of MTS1 exons 1alpha and 2 was found and MTS1 RNA was detected in the fourth case, but a rearrangement occurring 5' to MTS1 exon 1 alpha deleting MTS1 exon 1Beta was documented. One case presented a complex rearrangement. Germline configuration for MTS1 and MTS2 was found in only 7 cases. The localization of the 17 breakpoints occurring in the MTS locus were determined. Ten of them (59%) are clustered in a 6-kb region located 5 kb downstream to the newly identified MTS1 exon 1Beta. No rearrangement disrupting MTS2 was detected and more rearrangements spared MTS2 than MTS1 (P<.01). MTS1 but not MTS2 RNA was detected by Northern blotting in the human thymus. These data strongly suggest that MTS1 is the functional target of rearrangements in T-ALL. MTS1 inactivation, observed in at least 80% of T-ALL, is the most consistent genetic defect found in this disease to date.