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Biomedical subjects

J Roland

Publications and source records attributed to J Roland.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Multislice CT: principles and new CT-scan applications].

The introduction of new array detector technology for multislice CT improves CT-scan capabilities. Compared to single-slice helical CT, this technique offers three significant advantages: the pitch can be increased by a factor of 4, resulting in shorter acquisition times and contrast media saving, the temporal and spatial resolution are improved and the slice thickness can be freely and retrospectively selected. This technique promises to revolutionize radiological practice, just as spiral systems did a decade ago. Multislice CT is particularly suitable for exploring the chest, the heart and the vessels. It is also specially useful for musculo-skeletal explorations and trauma patients.

Animals↗
PubMed1999

Influence of landscape on the population genetic structure of the alpine butterfly parnassius smintheus (Papilionidae)

Four microsatellite DNA markers were developed which were used to examine the relationship between landscape and population genetic structure among a set of populations of the butterfly Parnassius smintheus located in the foothills of the Canadian Rockies. Detailed information on the dispersal of adult butterflies among this same set of populations was available. Simple and partial Mantel tests were used to examine the relationships between genetic distances, predicted rates of dispersal, and a number of landscape variables, all measured pairwise for 17 sample sites. Nei's standard genetic distance was negatively correlated with predicted dispersal. We observed a significant pattern of isolation by distance at a very small spatial scale. The distance between sites that was through forest was a stronger predictor of genetic distance than the distance through open meadow, indicating a significant effect of landscape on population genetic structure beyond that of simple isolation by distance. Our results suggest that rises in the tree-line in alpine areas, caused by global warming, will lead to reduced gene flow among populations of P. smintheus.

Journal Article↗
PubMed1999

The synthetic CD4 exocyclic CDR3.AME(82-89) inhibits NF-kappaB nuclear translocation, HIV-1 promoter activation, and viral gene expression.

We have previously shown that the synthetic aromatically modified exocyclic (AME) analog (CDR3.AME(82-89), derived from the CDR3 (residues 82-89) region of CD4 domain 1, inhibits replication of human immunodeficiency virus type 1 (HIV-1) in infected cells. In this work, we investigated the mechanism by which this inhibition is achieved. Although cells exposed to HIV-1 and treated with the CDR3.AME(82-89) peptide did not release viral particles for more than a week and kept surface expression of CD4, viral DNA was found in those cells 24 h after virus exposure, indicating that the CDR3.AME(82-89) analog does not prevent virus entry. However, virus transcription remained extremely low in infected cells, as demonstrated by the study of spliced HIV-1 mRNA in cultures treated with CDR3.AME(82-89) 72 h postinfection. Finally, the CDR3.AME(82-89) peptide was found to be a potent inhibitor of HIV-1 promoter activity and nuclear factor-kappaB translocation, indicating that the antiviral property of this peptide is, at least in part, linked with the ability of the molecule to prevent HIV-1 transcription.

Anti-HIV Agents↗
PubMed1999

Bone marrow content measured in radioimmune bone marrow scintigraphy: intra- and inter-observer variability.

The aim of this study was to assess the possible quantification of vertebral residual bone marrow content relative to the bone marrow content of a non-irradiated vertebra. This method is based on the vertebral count activity, measured using radioimmune bone marrow scintigraphy. First, however, we had to evaluate intra- and inter-observer variability. In three patients who underwent radioimmune bone marrow scintigraphy, two independent observers measured the count density in 51 (15 lumbar and 36 thoracic) vertebrae using a manually drawn region of interest. To evaluate intra- and inter-observer variability, we calculated the means and standard deviations of the differences between measurements. Bland-Altman plots were drawn for all vertebrae as well as for three subgroups of vertebrae (the upper thoracic spine, D1-D6; the lower thoracic spine, D7-D12; and the lumber spine, L1-L5). For all vertebrae, the mean (+/- S.D.) difference, expressed as a percentage of the overall mean, was -0.44 +/- 3.3% for observer 1 and -0.3 +/- 2.1% for observer 2 for intra-observer variability; inter-observer variability varied from 0.55 +/- 3.9% to 1.28 +/- 3.7%. On the Bland-Altman plots, the data points were evenly distributed above and below the 0-line and the linear regression equations matched the line of equality almost perfectly. This pattern was observed for all the vertebrae as well as for the subgroups of vertebrae. In conclusion, our results show that the intra- and inter-observer variabilities are not great, confirming that this technique is simple and robust and can be used for further quantification of bone marrow content in the axial skeleton.

Adult↗
PubMed1998

British Diabetic Association guidelines on genetic and immune screening for type 1 diabetes mellitus.

The following article is a report from the Chairman of the Professional Advisory Committee of the British Diabetic Association. The committee, with the help of a number of experts currently working in the field, produced a set of guidelines intended for use by health care professionals on the issues around genetic screening for Type 1 diabetes mellitus. The guidelines were approved by the Board of Management of the British Diabetic Association and we publish them here.

Autoantibodies↗
PubMed1998

Autoantibodies to polymorphonuclear neutrophil elastase do not inhibit but enhance elastase activity.

Polymorphonuclear neutrophils (PMNs) of patients with active Wegener's granulomatosis and PMN activated in vitro express elastase on their surface as detected by autoantibodies derived from patients with ANCA-positive vasculitis or chronic staphylococcus infections. The PMN-associated elastase was enzymatically active. By affinity-purified autoantibodies to elastase, the enzymatic activity was further enhanced as measured either by a chromogenic peptide or by elastin as substrate. Antibodies to human elastase from mouse or from sheep also enhanced elastase activity, whereas unrelated immunoglobulins had no effect. Taken together, our data indicate that autoantibodies to elastase are not inhibitory but upregulate the elastase activity and thereby might contribute to tissue damage.

Animals↗
PubMed1998

An autopsy study of the prostate in acquired immunodeficiency syndrome: evidence for excessive apoptosis and intracytoplasmic epithelial inclusions.

We describe a combination of epithelial cell apoptosis and intracytoplasmic inclusions in prostatic epithelium in 6 patients who died from the acquired immunodeficiency syndrome. Two different types of apoptosis were detected: simple cell shrinkage and exploding glandular cells. No intracellular or extracellular viral particles were detected, either ultrastructurally or immunohistochemically. Intracytoplasmic inclusions are apoptotic bodies in a state of degradation and in close association with lipofuscin. The cell degeneration we observed confirms the theory that increased apoptotic cell depletion is responsible for weight loss in the acquired immunodeficiency syndrome. In the prostate itself, the combination of excessive apoptosis and active phagosomal digestion of apoptotic bodies presents a "human model" of postcastration rat ventral prostate, under the conditions of severe immune deficiency.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Primary cerebral lymphoma visualised by means of In-111-pentetreotide scintigraphy.

Primary lymphoma of the central nervous system, until recently representing about 1% of all brain tumours, shows a dramatically increased incidence in the general population as well as in high-risk groups (immunocompromised, AIDS), and may rise up to 6% in a population of AIDS patients. The clinical presentation is variable and cannot reliably be distinguished from other intracerebral tumours. At present, CT and MRI are the methods of choice for diagnosing cerebral lymphomas. However, their characteristics are not specific. The radiological picture may suggest glioma, meningioma, metastatic carcinoma or even a cerebrovascular accident. A labelled somatostatin analogue (pentetreotide) has been proposed as a new tracer for the imaging of somatostatin receptors, which have been identified by immunocytochemical or radioimmunoassay techniques in several organ systems. Somatostatin receptors were also identified in surgical biopsy samples from patients with Hodgkin and non-Hodgkin lymphoma and extracerebral lymphoma has already been visualised in vivo by means of In-111-labelled pentetreotide. While CT images of the brain showed a regression of the tumour after radiotherapeutic treatment, the scintigraphic images showed persistence of the tumoural tissue, corresponding with the clinical evolution and outcome. Furthermore, the absence of extra-cerebral lymphoma tissue, seen on the whole body images, was confirmed by post-mortem examination. To our knowledge, this is the first report of a primary intracerebral lymphoma visualised by means In-111-pentetreotide.

Aged↗
PubMed1997

[Imaging of osteoarticular diseases of the anterior chest wall].

The purpose of this paper is to present a pictorial display of osseous and articular lesions of the anterior chest wall. The role of CT and MR imaging in such disorders is emphasized. Imaging of the anterior thoracic wall by plain films is particularly difficult. However numerous disorders may be encountered. They include inflammatory hyperostosis and sclerosis of the clavicle and the sternum, condensing osteitis and post-traumatic osteolysis of the clavicle, radiation osteitis of the sternum and the ribs, septic arthritis of the sternoclavicular joint, primary and secondary tumors of the sternum and the ribs. We illustrate a spectrum of such lesions in which CT and MR imaging provides acute evaluation of both soft tissue and bone details.

Clavicle↗
PubMed1997

[Branchial cyst of unusual localization: report of a case and considerations on organogenesis].

We report a case of branchial cyst of unusual location. A asymptomatic 41-year-old man had a nontender deeply located left neck mass. Sonography, CT scan, and MRI showed a cystic lesion posterior to the sternocleidomastoid muscle. The diagnosis of branchial cyst much debated because of this atypical location was confirmed by histologic analysis after surgical resection. During organogenesis, the important caudal proliferation of the second branchial arch generates a transient cavity, the cervical sinus, which finally becomes obliterated. The incomplete obliteration of which can result in a sinus, fistula or cyst. Such cysts typically lie at the level of the mandibular angle, anterior to the sternocleidomastoid muscle. This location has been regarded as a major diagnosis criteria, but it is not absolute. The sternocleidomastoid muscle develops apart from the branchial apparatus, caudally and anteriorly. As a result the cysts which are located on an inferior portion of the cervical sinus can lie posterior to this muscle.

Adult↗
PubMed1996

Enzyme immunometric assay of thyroliberin (TRH).

An enzyme immunometric assay of thyroliberin (TRH) using monoclonal antibodies and a derivatization procedure is described. This assay, named SPIE-IA, involves a four step procedure after chemical derivatization of TRH and biological samples by diazotized APEA. Step 1: derivatized TRH was immunocaptured by a monoclonal anti-TRH antibody coated on a 96-well microtiter plate. Step 2: after washing, derivatized TRH was cross-linked via its amino group to the wells using glutaraldehyde. Step 3: washing and treatment with NaOH. Step 4: measurement of bound TRH using a monoclonal anti-TRH antibody labeled with acetylcholinesterase. The minimal detectable concentration was 0.1 pmol/ml: with a coefficient of variation less than 10% in the 0.156-10 pmol/ml range. This assay is 26-fold more sensitive and more specific than the competitive enzyme immunoassay using the same monoclonal capture antibody, derivatized TRH and TRH-acetylcholinesterase conjugate as tracer. Good correlation was observed between SPIE-IA and a sensitive competitive enzyme immunoassay using polyclonal antibodies.

Animals↗
PubMed1996

Genomic structure and precise mapping of a thymic regulatory region on mouse chromosome 17 revealed by a c-myc transgene insertion.

In one transgenic strain harboring a human c-myc proto-oncogene construct, the transgene was actively and exclusively expressed in the thymus, where it contributed to the development of lymphoma that corresponded to CD4(+)CD8(+) cells. Here, we have pursued the analysis of transgene expression in healthy transgenic mice and show that transgene activation occurs in the thymus 3 days before birth, at a time when CD4(+)CD8(+) lymphocytes emerge. In the adult, its expression is restricted to the CD4(+)CD8(+) cells. The region flanking the transgene insertion site was isolated and made it possible to map the preintegration locus, hereafter called Tsil (for thymus-specific integration locus) on chromosome 17 between D17Rp11e and Ras12-3. A YAC that contains both Tsil and the Pim2 locus, previously shown to be involved in progression of T-cell lymphoma, was isolated. Analysis of Tsil offers a unique opportunity to identify a regulatory region or a gene that might play an important role in T-cell maturation.

Animals↗
PubMed1996

Oesophageal motility disorders in patients with psychiatric disease.

Clinical and experimental observations indicate that the motility of the oesophagus may be affected by emotional stimuli. The aim of this study was to evaluate the incidence of oesophageal contractility impairment in patients suffering from a psychiatric disorder. Fifty-one patients admitted to the psychiatric department were submitted to an oesophageal transit study by means of krypton-81m. All patients with an abnormal oesophageal transit underwent manometry and endoscopy. The level of depression and anxiety was evaluated by the treating psychiatrist, using the Hamilton Depression and Anxiety Rating Scales. The oesophageal transit was abnormal in 13 patients. Two of these 13 patients refused manometric investigation. In ten of the 11 remaining patients, the manometry revealed functional motor abnormalities. Endoscopy, performed in all these ten patients, was normal. In conclusion, a high percentage of oesophageal contractility disturbances was found in psychiatric patients complaining of anxiety and/or depression. These abnormalities were detected by scintigraphy as well as by manometry. Owing to the normal endoscopic findings, these contraction abnormalities are likely to reflect a functional motor impairment.

Anxiety↗
PubMed1996

Pontine veins. MRI cross-sectional anatomy.

The pons is covered by a rich venous network offering numerous vascular landmarks in MRI and during surgery. We present an original study of the veins as they appear on MR multiplanar scans after gadolinium IV injection. This prospective study is based on 40 consecutive patients with normal posterior fossa structures. One of the major venous collectors follows the pons: the superior petrosal v. was identified on MRI in 95% of our cases. Its hooklike extremity drains into the superior petrosal sinus. The inferior petrosal v. was never identifiable. The superficial pontine venous network are identified in 72.5% of cases in the axial plane and were organised in longitudinal and transverse collectors, whose MR aspects are presented here.

Humans↗