Biomedical subjects

T Jernigan

Publications and source records attributed to T Jernigan.

8 recordsLinked to original sources

PubMed1996

Low body weight in Alzheimer's disease is associated with mesial temporal cortex atrophy.

There are reports of weight loss and low body mass index (BMI) in patients with AD. The mesial temporal cortex (MTC) is involved in feeding behavior and memory and is preferentially involved in AD. We studied 74 subjects, including 58 AD patients and 16 control subjects, to determine whether BMI is associated with atrophy of the MTC or other brain regions. We used MRI morphometric analysis to provide measures of regional brain atrophy. AD patients had significant brain atrophy in all measured brain regions, except the white matter, compared with normal control subjects. The MTC was the only brain region significantly associated with BMI in AD patients (r = 0.39, p = 0.003). Multiple-regression analysis indicated that addition of brain regions other than the MTC to the model did not significantly add to the prediction of BMI. We conclude that low BMI correlates best and specifically with MTC atrophy. This finding supports a connection between limbic system damage and low body weight in AD.

Aged↗

PubMed1995

Gender differences in schizophrenia.

In an assessment of gender differences in schizophrenia, 85 outpatients (53 men and 32 women) with schizophrenia were evaluated for illness history, symptom severity, IQ, neurocognitive status, cerebral volume loss, and cortical asymmetry. Social functioning was assessed using marital status, independent living skills, and employment status. Significant gender differences were found, as women were on lower doses of neuroleptic medications and more frequently met criteria for paranoid and disorganized subtypes of schizophrenia than men. Women also were better educated and more often married, living independently, and employed. No gender differences were found in present age, symptom severity, neurocognitive functioning, or clinical magnetic resonance imaging scan readings. Our findings suggest that women may experience less of the adverse interpersonal psychosocial consequences of schizophrenia than men, even when symptom and neurocognitive status is equivalent between groups. However, more extensive investigations are warranted to better understand the role of pathophysiological or social mechanisms in gender differences.

Activities of Daily Living↗

PubMed1995

Quantitative magnetic resonance imaging of the brain in late-life schizophrenia.

OBJECTIVE: This study compared morphometric analyses of brain regions in elderly subjects with early- or late-onset schizophrenia to identify structural abnormalities responsible for schizophrenia. METHOD: Quantitative analyses of magnetic resonance images of the brain were performed in 16 patients with DSM-III-R-diagnosed late-onset schizophrenia (i.e., onset after age 45), 14 patients with early-onset schizophrenia, and 28 normal comparison subjects, all of whom were over the age of 45. The three groups were similar in age, sex, education, and handedness. RESULTS: The groups differed significantly in ventricular and thalamic volumes. The patients with late-onset schizophrenia had significantly larger ventricles than the normal comparison subjects and significantly larger thalamic volumes than the patients with early-onset schizophrenia. There were no significant linear correlations between thalamic volume and age at onset, duration of illness, or mean current neuroleptic dose. CONCLUSIONS: Differences in thalamic volume may account for the putative disruption in thalamofrontal ciruitry in schizophrenia.

Age of Onset↗

PubMed1994

Development studies of Aurelia (jellyfish) ephyrae which developed during the SLS-1 mission.

Aurelia polyps (scyphistomae) and ephyrae were exposed to microgravity for nine days aboard the space shuttle during the SLS-1 mission. During strobilation, polyps segment transversely and each segment develops into an ephyra. Polyps were induced to strobilate at 28 degrees C, using iodine or thyroxine, at L(Launch)-48h, L-24h, and L+8h. Ephyrae developed in the groups tested in space and on Earth. The number of ephyrae formed per polyp was slightly higher in the L+8h groups as compared with those induced at L-24h and L-48h. On Earth, iodine is used by jellyfish to synthesize jellyfish-thyroxine (Jf T4), needed for ephyra production. Since iodine-treated polyps strobilated and formed ephyrae in space, it appears that jellyfish can synthesize Jf-T4 in space. Indeed, two groups of polyps not given inducer formed ephyrae [correction of ephryae] in space, presumably due to enhanced Jf-T4 synthesis, utilization or accumulation. Some ephyrae that formed in space were also fixed in space on Mission Day (MD) 8; others were fixed post-flight. Examination of living ephyrae with the light microscope and fixed ones with the Scanning and Transmission Electron Microscopes revealed that those which developed in space were morphologically very similar to those which developed on Earth. Quantitation of arm numbers determined that there were no significant differences between space and Earth-developed ephyrae. Pulsing abnormalities, however, were found in greater numbers (18.3%) in space-developed ephyrae than in Earth-developed controls (2.9%). These abnormalities suggest abnormal development of the graviceptors, the neuromuscular system, or a defect in the integration between these systems in apparently microgravity-sensitive animals.

Animals↗

PubMed1994

Graviceptor development in jellyfish ephyrae in space and on Earth.

Graviceptor (rhopalium) development in Aurelia aurita ephyrae which developed on Earth and in space during the nine-day NASA SLS-1 mission was compared. The space-developed ephyrae made graviceptors which were morphologically similar to those of their ground-based controls. Rhopalia of both groups developed statocysts with statoliths, ocelli, ciliated mechanoreceptor cells, and immature touch-plates with one type of hair cell. The number of rhopalia formed per arm of ephyrae of both groups revealed no significant differences. The number of statoliths formed per rhopalium was statistically higher in ephyrae which were induced to form in space with iodine than in L(Launch)+8h controls. Statolith numbers were not significantly different between Earth-formed control ephyrae and those formed from polyps induced on Earth and then sent into space 24h and 48h later. Statolith loss from rhopalia was significantly enhanced in the space-maintained ephyrae in ASW as compared to their controls. Ephyrae formed through thyroxine treatment and those maintained in thyroxine in space had statolith numbers comparable to thyroxine-treated controls. Pulsing abnormalities seen in some space-developed ephyrae suggest that some space-formed ephyrae may have developed abnormal rhopalia because normal rhopalia development and function is necessary for normal pulsing.

Animals↗

PubMed1992

Past substance abuse and clinical course of schizophrenia.

To evaluate the effects of previous alcohol and drug use on the course and symptoms of schizophrenia, the authors compared 34 patients with schizophrenia who had histories of substance abuse with 17 patients with schizophrenia who were lifelong abstainers. Surprisingly, they did not find that individuals with past histories of abuse were more impaired or had more symptoms.

Adult↗

PubMed1990

Neuropsychological, neurological, and neuroanatomical profile of Williams syndrome.

The general aim of our research is to understand the brain mechanisms that underlie language and cognition. In this paper, we present a new line of investigation which attempts to forge links between a specific neurodevelopmental disorder, a specific neuropsychological profile, and abnormal brain organization. We report on a dissociation between language and cognitive functions in Williams syndrome adolescents, in contrast to age- and IQ-matched Down syndrome adolescents. The Williams syndrome individuals exhibit an unusual fractionation of higher cortical functioning, with marked cognitive deficits, but selective sparing of syntax. Differences in spatial cognitive abilities in the 2 groups are investigated, showing peaks and valleys of abilities specific to Williams syndrome individuals. These neurobehavioral profiles are explored in light of new evidence regarding neurologic and neuroanatomical differences between the 2 matched groups of adolescents. Results from these combined studies should help clarify the neural systems that mediate language and cognitive functions.

Abnormalities, Multiple↗

PubMed1988

Brain computerized tomography in subtypes of severe chronic schizophrenia.

Computerized tomographic (CT) brain scans were obtained in severely ill, chronic schizophrenic patients hospitalized in a long-term in-patient facility of a Veterans Administration hospital, and compared to CT brain scans from an age, sex and education-matched normal control population. In contrast to results obtained in our previous studies with younger, less severely ill, chronic schizophrenic patients, the current study population exhibited significantly increased rankings of third ventricular size and of fronto-tempero-sylvian atrophy, compared to normal control subjects.

Adult↗