Biomedical subjects

A J Conrad

Publications and source records attributed to A J Conrad.

24 records · Page 2Linked to original sources

PubMed1993

Trans-blood-brain-barrier albumin leakage and comparisons of intrathecal IgG synthesis calculations in multiple sclerosis patients. Multiple Sclerosis Study Group, Alpha Interferon Study Group, and Azathioprine Study Group.

We compared four equations for estimating intrathecal IgG synthesis (Tibbling and Link IgG index (T/L), Schuller and Sagar (S/S), Reiber and Felgenhauer (R/F), and Tourtellotte (T) equations) using data from chronic progressive MS patients. For normal albumin leakage (AL) (< 75 mg/day-intact BBB), T (r = 0.15) and R/F (r = 0.10) showed comparable positive correlations with trans-BBB AL, T/L (r = -0.10) was negative and S/S was uncorrelated (r = 0.05). For abnormal AL (> or = 75 mg/day), the R/F (r = -0.24), S/S (r = -0.37) and the T/L (r = -0.22) equations overcorrected, whereas the T (r = 0.07) equation values did not correlate with AL. The albumin index and trans-BBB albumin leakage rate formulae gave essentially identical estimates of BBB leakage (r = 0.99, P = 0.0001). We conclude that in chronic progressive MS patients the R/F, T/L and S/S formulae overcompensate for large abnormal T-BBB albumin leakage rates. The T formula corrected best for IgG transudate at high AL rate values in MS.

Albumins↗

PubMed1993

On classification of post-mortem multiple sclerosis plaques for neuroscientists.

Plaque classification is proposed based on observation of 348 plaques from 52 post-mortem multiple sclerosis (MS) cases. Four plaque types, ranging from 'earliest lesion' to 'inactive', are described according to immunological activation and degree of demyelination, seen by expression of the Major Histocompatibility Complex (MHC) Class II molecule, HLA-DR, and by Oil Red O staining, respectively. 40% of the plaques were inactive. This result highlights the need for a description of plaque activity for studies of the etiopathogenesis of MS; that is, the earliest and/or the most active plaques should contain the causative agent whereas the burnt out plaques should not.

Adult↗

PubMed1991

Hippocampal pyramidal cell disarray in schizophrenia as a bilateral phenomenon.

In a continuing quantitative study of hippocampal cell orientation in schizophrenic subjects and nonschizophrenic control subjects, a pattern of right hemispheric cell disorganization in schizophrenic subjects, as robust as that previously described in the left hemisphere, was shown. The study was based on tissue from 11 schizophrenic and seven approximately age-matched control subjects from a Veterans Administration Medical Center. Using a new measuring technique that proved complementary and superior to the method formerly used, we determined the axes of orientation for approximately 10,800 neurons. A significant difference in cell disorganization was found between schizophrenic and control subjects. From separate analyses of the interface zones among the various hippocampal cell sectors, this difference was found to be significant at the interfaces between cornu ammonis zones 1 and 2 and zones 2 and 3. Analysis of the pattern of disorganization numbers suggests a bimodal distribution in which the cell orientation values of one group of schizophrenic subjects overlap those of the nonschizophrenic control group, while the cell orientation values of a second group significantly exceed those of the control population. Although some recent studies have suggested that schizophrenia may be related exclusively to the left hemisphere, the results of this study indicate that schizophrenia-related structural changes involve the right hemisphere as well. Thus, schizophrenia may be a bilateral rather than unilateral disorder.

Adult↗

PubMed1987

Schizophrenia and the hippocampus: the embryological hypothesis extended.

Recent studies suggest that consistent structural changes exist in the hippocampi of schizophrenic patients. These alterations are characterized by a significant degree of disorientation of the hippocampal pyramidal cells when compared with age-matched nonschizophrenic controls. The degree of neuronal disorientation seems to correlate positively with the severity of the clinical picture. A hypothesis on the pathogenesis of this process, suggested in an earlier article, is extended here. Putative maternal infection with one of several neuraminidase-bearing viruses, especially during the second trimester of pregnancy, may severely affect the migration of primitive neurons into the primordial hippocampus. The "neuraminidase effect," expressed through alteration of the normal sequential patterns of N-CAM (neuronal-cell adhesion molecule) maturation, may result in the cellular disarray we have noted. This alteration may prove useful as a cell marker for schizophrenia, even though its actual relation to clinical symptomatology has still to be evaluated. Genetic factors also are believed to be involved, perhaps in the form of certain patterns of reduced immunocompetence, which might render the mother more susceptible to viral infection.

Adult↗

PubMedDate not supplied

Common laparoscopic procedures in swine: a review.

Swine serve as excellent models for many laparoscopic procedures. As more operations are being performed laparoscopically, it is essential for the surgeon to have a good understanding of laparoscopic techniques. This manuscript reviews some commonly performed laparoscopic operations with an emphasis on models in swine. Porcine anatomy is generally similar to human anatomy with some minor differences. Practice on porcine models can help refine techniques and increase efficiency and skill.

Animals↗

PubMedDate not supplied

Relationship between prior course of illness and neuroanatomic structures in bipolar disorder: a preliminary study.

OBJECTIVE: In this preliminary study, we examined the relationships between prior course and severity of illness and size of the hippocampus, temporal lobes, and third and lateral ventricles in patients with bipolar disorder. BACKGROUND: The few studies that have investigated relationships between course of illness measures and neuroanatomic structures in patients with bipolar disorder found divergent results. METHOD: Twenty-six outpatients, who met Diagnostic and Statistical Manual, Third Edition - Revised (DSM-III-R) criteria for bipolar disorder, received a magnetic resonance imaging (MRI) scan, from which volumes of the temporal lobes, hippocampi, third ventricle, and areas of the lateral ventricles were calculated. Prior course of illness variables were determined using the NIMH Life-Chart Method and were correlated to the volumetric measures of neuroanatomic structures using multiple regression analyses. RESULTS: A longer duration of illness was paradoxically associated with a larger left temporal lobe volume whether patients with a history of substance abuse were removed from the analyses. CONCLUSIONS: Additional studies are needed to both replicate and further examine the association of prior course of illness and larger hippocampal and ventricular volumes in bipolar disorder.

Adult↗