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Biomedical subjects

P J Dubois

Publications and source records attributed to P J Dubois.

At least 19 recordsLinked to original sources
PubMed1997

A case report: immune responses and clinical course of the first human use of granulocyte/macrophage-colony-stimulating-factor-transduced autologous melanoma cells for immunotherapy.

The first use of granulocyte/macrophage-colony-stimulating-factor-transduced, lethally irradiated, autologous melanoma cells as a therapeutic vaccine in a patient, with rapidly progressive, widely disseminated malignant melanoma resulted in the generation of a novel antitumour immune response associated with partial, albeit temporary, clinical benefit. An initially negative reaction to non-transduced, autologous melanoma cells was converted to a delayed-type hypersensitivity (DTH) reaction of increasing magnitude following successive vaccinations. While intradermal vaccine sites showed prominent dendritic cell accrual, DTH sites revealed a striking influx of eosinophils in addition to activated/memory T lymphocytes and macrophages, recalling the histology of challenge tumour cell rejection in immune mice. Cytotoxic T lymphocytes (CTL) reactive with autologous melanoma cells were detectable at high frequency after vaccination, not only in limiting-dilution analysis, but also in bulk culture without added cytokines. Clonal analysis of CTL showed a conversion from a purely CD8+ response to a high proportion of CD4+ clones following vaccination. A prominent acute-phase response manifested by a five- to tenfold increase in C-reactive protein was observed, as was a systemic eosinophila. Vaccination resulted in the regression of axillary lymphatic metastases, stabilisation of pulmonary metastases, and a dramatic, reversible increase in cerebral oedema associated with multiple central nervous system metastases: however, lesions in the adrenal glands, pancreas and spleen proved refractory. The antitumour effects and immune response were not detectable 2 months following the last vaccination. Irradiation of the extensive cerebral metastases resulted in rapid deterioration and death of the patient.

Autopsy↗
PubMed1983

Computerized tomographic and pathologic studies of the untreated, quiescent, and recurrent glioblastoma multiforme.

Pathological findings in 20 cases of glioblastoma multiforme were correlated with clinical histories and computerized tomographic (CT) scans. This was done to define the neoplasm in three stages: before treatment, during remission, and during recurrence. The untreated lesions were markedly cellular neoplasms composed predominantly of small anaplastic cells. The radiographic central region of low density was necrosis, the enhancing rim was a cellular zone of viable neoplasm, and the perilesional low-density area was edema with infiltrating tumor. In these 20 cases, all of the identifiable neoplasms lay within the zone of peritumoral edema or contrast enhancement, although small anaplastic cells may have been present in more distant regions. The lesions in remission were remarkable for their minimal mass effect, discrete nature, extensive necrosis, and content of large bizarre glia. The large cells were confined to the original tumor bed and were consistent with neoplastic cells inactivated and immobilized by radio- and chemotherapy. These lesions were accurately localized by CT scanning. The recurrent lesions were heterogeneous, but most were formed of widely disseminated small anaplastic cells. The highly cellular regions of such lesions could be localized by CT scanning, but CT could not detect less cellular foci in the cerebrum, cerebellum, or brain stem. In one patient, the contrast-enhancing lesions of "recurrence," were foci of radionecrosis, underscoring the difficulty in distinguishing this entity from recurrent neoplasm.

Adult↗
PubMed1982

Radiographic quantitation of reversible blood-brain barrier disruption in vivo.

Cranial computed tomography (CT) was used to quantitate disruption of the blood-brain barrier (BBB) in dogs in vivo following intracarotid infusion of hypertonic mannitol. The degree of opening varied with the same dose and infusion rate. The ratio of contrast enhancement in brain vs. venous blood was elevated in 4 of 5 mannitol-treated animals, with the greatest enhancement occurring in the ipsilateral basal ganglia and cortical gray matter. The statistical significance and reproducibility of the derived CT numbers used for brain and venous blood calculations, as well as the linear relationship between iodine concentration and CT enhancement, was affirmed by obtaining multiple consecutive scans.

Animals↗
PubMed1982

Late sequelae of spinal cord trauma. Myelographic and surgical correlation.

Eighteen patients with posttraumatic paraplegia were examined myelographically at 2 months to 30 years after the injury, and the findings correlated with surgical exploration. The following six myelographic patterns were seen: 1) tethered cord and subarachnoid adhesions; 2) proximal cord cysts; 3) loculated subarachnoid cysts; 4) proximal cord atrophy; 5) extradural fibrosis; and 6) complete obliteration of the subarachnoid space at the level of trauma due to extradural fibrosis and/or bone encroachment on the vertebral canal. Myelography with or without computerized tomography (CT) accurately reflected the gross pathological process. The examination is indicated prior to surgical intervention: the structural lesion in four patients extended two or more vertebral levels above the site of the original bone injury and was not easily predictable preoperatively. When combined with CT, myelography allowed evaluation of the transverse anatomy of the vertebral canal and its contents; it was especially useful when the canal was narrowed or distorted by bone and soft tissue. Water-soluble contrast media provided a more detailed evaluation of the spinal cord and subarachnoid space, and were the preferred agents. If a posttraumatic syrinx is suspected, these are the agents of choice.

Adult↗
PubMed1981

Rapid serial cranial computed tomography for tumor diagnosis.

Rapid serial computed tomography (RSCT) provides more information about the cerebral cortical capillary bed and leptomeningeal vessels than conventional enhanced computed tomography (CT). This increased neuroanatomical definition has potential value for separating intra- from extracerebral tumors in selected cases. RSCT offers better visualization of the angioarchitecture of highly vascular tumors than conventional enhanced CT. However, CT scans delayed several minutes after contrast administration are more useful for evaluating the extent of hypovascular tumors. Time-density curves were of limited value for tumor evaluation. However, the peak increase of Hounsfield units did correlate well with the degree of tumor vascularity assessed angiographically.

Adult↗
PubMed1981

Case report. Malignant change in an intracranial epidermoid cyst.

A malignant epidermoid tumor invading the fourth ventricle had histologic features that indicated malignant transformation in a benign epidermoid cyst. The computed tomographic (CT) findings correlated precisely with the histologic features, revealing both pathologic enhancement and a low attenuation zone. The spectrum of described CT findings in intracranial epidermoids is reviewed and contrasted with the appearance encountered in the present case.

Brain Neoplasms↗
PubMed1981

Case report. Rapid development of cerebral atrophy due to perinatal herpes simplex encephalitis.

A case of neonatal herpes simplex virus (HSV) encephalitis is reported in which diffuse cerebral hemorrhagic lesions were seen in the neonatal period. Severe progressive cortical atrophy with parenchymal calcification developed over the subsequent 9 months, resulting in a striking computed tomography (CT) appearance. The range of CT findings in neonatal HSV encephalitis is reviewed, and differential diagnostic considerations in the present case are discussed.

Atrophy↗
PubMed1981

Case report. Atypical findings in adrenoleukodystrophy.

Computed tomography (CT) in a child with typical clinical and biochemical features of adrenoleukodystrophy (ALD) revealed striking pathologic enhancement in the centra semiovalia, posterior corpus callosum, and corticospinal tracts within the internal capsules, cerebral peduncles, and basis pontis. Central calcifications were detected within otherwise typical symmetrical low attenuation lesions in the periatrial white matter. These findings further expand the spectrum of CT abnormalities in ALD and may represent a link between the recently described Type 1 and Type 11 CT patterns.

Adrenal Glands↗
PubMed1981

Meningiomas associated with large cysts with neoplastic cells in the cysts walls. Report of two cases.

Two adults presented with frontal lobe masses. As visualized by computerized tomography, both lesions were large cysts with contrast-enhancing mural nodules and enhancing circumferential rims. En bloc resections of the mural nodules and cyst walls were performed. Pathological evaluation of each nodule disclosed a meningioma, and neoplastic cells were found in the distant cyst walls. Although the walls of large cysts associated with some meningiomas have been composed of reactive glia or collagen, the neoplastic character of the cysts in the present cases underscores the need for resection and careful pathological evaluation of the large cysts associated with meningiomas.

Aged↗
PubMed1980

Hyperventilation induced abnormalities in the electroencephalogram of children with Moyamoya disease.

Two cases of Moyamoya disease in children are presented. The EEG of each child demonstrated minimal abnormalities at rest. However, during 3 min of hyperventilation, the record developed rhythmic delta activity which persisted in excess of 5 min after termination of over breathing. This activity did not respond to glucose administration and was maximal in the areas correlating with the clinical symptoms. It appears to represent a physiologic correlate of an abnormal vascular response to hypocapnia. Although admittedly a non-specific response, the persistence of delta activity easily provoked by hyperventilation, the topographic correspondence to the ultimately demonstrated vascular anomaly, and the lack of response to glucose ingestion represent a combination of factors which, in the appropriate clinical setting, are distinctive and of diagnostic value. Currently, invasive arteriography is required for definitive diagnosis of Moyamoya. Improved selection of children for invasive studies may be accomplished by EEG screening.

Adolescent↗
PubMed1980

CT-guided fine needle aspiration biopsy of orbital optic nerve tumors.

Biopsies were done for seven patients who had blinding optic nerve tumors or inflammations, using the fine needle aspiration technique guided by the CT scan. Cytologic material was recovered in this manner in all cases, which allowed the rendering of diagnoses. This allowed for therapeutic planning with minimal therapeutic invasion.

Adolescent↗
PubMed1980

A preliminary investigation of the role of dynamic computed tomography in renovascular hypertension.

This preliminary report describes the application of dynamic computed tomography (CT) to the study of the kidney. The study is a simple, rapid, noninterventional test that gives time--density perfusion curves for the renal cortices as compared with aortic perfusion. In normal subjects, renal cortical time--density curves almost parallel the aortic time--density curve. In theory, decreases in perfusion in the kidney should show a renal cortical perfusion curve that is flattened and no longer parallel to the aortic curve. An experimental model for renal infarction was developed in the dog. Time--density curves taken from the infarcted area do show a depressed renal perfusion curve, with a lower peak than the curve for the contralateral kidney. Dynamic CT may be useful in screening human subjects for possible renovascular hypertension.

Animals↗
PubMed1980

Distinction between obstructive and atrophic dilatation of ventricles in children.

The computed tomography (CT) scans of 92 infants and children were reviewed. Thirty-three had proven atrophy, and 44 had proven obstructive hydrocephalus. Twelve CT measurements were made, and the results were subjected to computer analysis. The pathologic patients were divided into three groups by ventricular size index: mild (33--39%), moderate (40--46%), and severe (greater than 46%) enlargement. Obstructive patients showed much greater measurements for the temporal horn diameter and the frontal horn radius. The angle of the frontal horn was narrower in the obstructed group than in the atrophic patients. As expected, there were significantly more sulci visualized in the atrophic group than in the obstructed group. Three of these four parameters were directly related to concentric expansion of the ventricles in the presence of obstructive hydrocephalus. This is contrasted with passive dilatation of the ventricular system with preservation of the normal ventricular configuration in atrophy. The temporal horn diameter, frontal horn radius, the angle of the frontal horn, and the number of sulci all distinguish between obstruction and atrophy with individual probabilities of less than 0.05. When used together, they assure a high probability of separating obstruction from atrophy. Preliminary data suggest that these findings may have application in adults, but the number of confirmed observations has been too small for statistical analysis.

Atrophy↗
PubMed1979

Fine-needle aspiration biopsy. Its use in orbital tumors.

Fifteen orbital tumors have been evaluated with the fine-needle aspiration biopsy (FNAB) technique. The best indication for FNAB is supposed malignant orbital disease. The technique has not been helpful in tumors or inflammatory disease with a high fibrous content. Lesions that are suspected of being pseudotumors are not recommended for FNAB since, even in histologic sections, they are notoriously difficult to distinguish from well-differentiated lymphocytic malignant lymphoma. Benign encapsulated tumors should not be subjected to FNAB.

Adult↗
PubMed1979

Tomography of the vestibular aqueduct in ear disease.

A controversy exists concerning whether or not roentgenographic narrowing or nonvisualization of the vestibular aqueduct is a specific sign for Meniere's disease. Of 190 ears that were evaluated, abnormal aqueducts were seen in 42.9% of ears with Meniere's disease, 45.4% of contralateral, noninvolved ears from patients with Meniere's disease, 41.3% of ears with diseases other than Meniere's disease, 30.4% of ears with no disease, and 51.6% of normal ears. Narrowing or nonvisualization of the vestibular aqueduct is a nonspecific roentgenographic sign that is seen in diseased, as well as in normal ears, and should not be used to make a diagnosis of Meniere's disease. Indications for polytomography in Meniere's disease include (1) preoperative evaluation of the aqueduct prior to endolymphatic shunt procedures and (2) exclusion of acoustic neurinomas or other organic causes of vertigo.

Adolescent↗
PubMed1979

Advantages of a fourth generation CT scanner in the management of patients with orbital mass lesions.

This presentation demonstrates the advantages of a fourth generation CT scanner in prognosis and localization of orbital space taking lesions, including its use as a localization guide for fine needle aspiration biopsy. It also provides an accurate means of follow-up of orbital lesions which have been either left in situ, partially excised, or excised. Six patients with difficult orbital problems of various types have been described to demonstrate how this high resolution CT scanner was utilized to improve the recognition and management of these problems.

Adult↗