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Biomedical subjects

L Richman

Publications and source records attributed to L Richman.

15 recordsLinked to original sources
PubMed2006

Structure and function of the superior temporal plane in adult males with cleft lip and palate: pathologic enlargement with no relationship to childhood hearing deficits.

BACKGROUND: In a previous study from our lab, adult males with non-syndromic cleft lip and/or palate (NSCLP) were shown to have significantly lower temporal lobe gray matter volume than matched controls. The current study was designed to begin a regional analysis of specific subregions of the temporal lobe. The superior temporal plane (STP) is a brain region involved in the governance of auditory processing and aspects of language. The cognitive deficit of subjects with NSCLP is characterized by specific deficits in language; therefore this region of the temporal lobe is particularly important to investigate in this population. The STP has been found to be structurally abnormal in subjects with dyslexia, another developmental disorder involving language deficit. The hypothesis for the current study was that the STP in subjects with NSCLP would be structurally abnormal and that the abnormality would be related to cognitive deficit, but not to developmental hearing deficit. METHODS: Manual tracing of the STP in NSCLP males and matched controls was performed on magnetic resonance imaging (MRI) scans. Ratios of STP to total temporal lobe gray matter volume were calculated and compared across groups. In addition, the morphology of the STP was correlated to cognitive function as well as measures of hearing deficit during infancy and childhood. RESULTS: Despite overall deficit in temporal lobe gray matter, the STP is disproportionately large in subjects with NSCLP compared to controls. Further, gray matter volume of the STP was inversely correlated with IQ and language test scores in CLP subjects. Hearing loss throughout childhood and adulthood was not significantly correlated with brain morphology. CONCLUSIONS: The structure of the superior temporal plane in adult males with NSCLP was disproportionately large. This abnormally increased volume was directly related to IQ, with greater STP volume being associated with lower cognitive functioning, thus characterizing the finding as 'pathologic enlargement'. Moreover, there was no relationship between the structure of the STP and measures of childhood hearing impairment, supporting the notion that the language deficits of this population are more likely due to abnormal brain development than to the effects of hearing deficit during childhood.

Adolescent↗
PubMed2001

Increased incidence of a midline brain anomaly in patients with nonsyndromic clefts of the lip and/or palate.

BACKGROUND AND PURPOSE: Nonsyndromic clefts of the lip and palate (CLP) are developmental craniofacial abnormalities that are often associated with cognitive dysfunction. This study was designed to evaluate, in patients with CLP, the presence of a specific midline brain anomaly (enlarged cavum septi pellucidi [CSP]) that has been shown in other developmental syndromes to be related to poor cognitive function. METHODS: Brain images were obtained using magnetic resonance imaging on 49 adult men with CLP and 75 healthy controls. Size of CSP was measured using consecutive coronal images. RESULTS: The incidence of large CSP in the CLP group was 8% (4 of 49), significantly higher than that found in the control group. In 2 of these 4 subjects, the anomaly was complete nonfusion of the septal leaflets, known as a combined CSP and cavum vergae. Furthermore, there was a significant inverse relationship of IQ and CSP in CLP patients that was not present in controls. That is, in individuals with CLP, the larger the CSP, the lower the IQ. CONCLUSIONS: Adult men with CLP have an increased prevalence of enlarged CSP. Moreover, this anomaly is directly related to cognitive deficits. This study provides further evidence that the development of the face and the development of the brain are intimately related and that defects in craniofacial development are most likely associated with defects in brain development.

Adult↗
PubMed2000

Abnormal brain morphology in patients with isolated cleft lip, cleft palate, or both: a preliminary analysis.

OBJECTIVE: The aim of this study was to determine whether adult men with cleft lip and palate (CLP) have aberrant cerebral morphology. DESIGN: Brain morphology of 14 adult men with isolated CLP were analyzed and compared with 14 healthy controls matched for sex, age, and parental socioeconomic status. SETTING: The research took place at a large, tertiary care hospital, with participation on an outpatient basis. PARTICIPANTS: The 14 males with CLP were recruited from a large cleft lip and palate registry, while their 14 matched controls were selected from a registry of healthy volunteers collected via the Mental Health Clinical Research Center. RESULTS: The males with CLP have significantly smaller cerebellar size (p = .04), significantly larger frontal lobes (p = .02), and significantly smaller temporal and occipital lobes (p = .02; p = .009, respectively). No significant difference in gray/white matter ratios or laterality were found. CONCLUSIONS: Adult males with CLP have a significantly different pattern of brain morphology, compared with healthy controls, which is most likely due to aberrant cerebral development. This study highlights the complex interaction and interdependence of craniofacial and cerebral development.

Adult↗
PubMed1998

Cyclin E2: a novel CDK2 partner in the late G1 and S phases of the mammalian cell cycle.

We report here the cloning and characterization of human and mouse cyclin E2, which define a new subfamily within the vertebrate E-type cyclins, while all previously identified family-members belong to the cyclin El subfamily. Cyclin E2/CKD2 and cyclin E/CDK2 complexes phosphorylate histone H1 in vitro with similar specific activities and both are inhibited by p27Kip1. Cyclin E2 mRNA levels in human cells oscillate throughout the cell cycle and peak at the G1/S boundary, in parallel with the cyclin E mRNA. In cells, cyclin E2 is complexed with CDK2, p27 and p21. Like cyclin E, cyclin E2 is an unstable protein in vivo and is stabilized by proteasome inhibitors. Cyclin E2-associated kinase activity rises in late G1 and peaks very close to cyclin E activity. In two malignantly transformed cell lines, cyclin E2 activity is sustained throughout S phase, while cyclin E activity has already declined and cyclin A activity is only beginning to rise. We speculate that cyclin E2 is not simply redundant with cyclin E, but may regulate distinct rate-limiting pathway(s) in G1-S control.

Amino Acid Sequence↗
PubMed1998

A chromatographic assay for heme oxygenase activity in cultured human cells: application to artificial heme oxygenase overexpression.

Heme oxygenase (HO) activity oxidizes heme, releasing carbon monoxide; heme iron; and biliverdin, which is converted to bilirubin by biliverdin reductase. Inducible HO-I expression is a marker of oxidative stress in mammalian cells, while noninducible HO-II contributes to basal HO activity. HO-I and HO-II activities are implicated in cellular antioxidant defense mechanisms. We describe a microassay for HO activity in cultured human cells, using high-performance liquid chromatography of biliverdin and bilirubin. The assay is sufficiently sensitive to quantify basal and inducible HO activity in various human cell types. We have established human cell lines overexpressing heme oxygenase-II activity in microsomes using a metallothionein promoter-regulated expression system. Stable transformants treated with ZnCl2 express up to ninefold induction of HO activity. We have constructed human cell lines overexpressing HO-II protein and activity (5-15-fold) in the absence of tetracycline, using the HtTA-1 cell line transfected with tetracycline-regulated expression vectors (Gossen et al., Proc. Natl. Acad. Sci. USA 89, 1992). Functional HO-II overexpressing clones will be useful in investigating anti- or pro-oxidant effects of HO activity during cellular oxidative stress.

Cell Line↗
PubMed1991

A comparison of memory and attention in Turner syndrome and learning disability.

Compared short-term verbal memory, sustained attention, and impulsivity in 13 children with Turner syndrome to 13 females and 14 males with learning disability who had neuropsychological patterns similar to the children with Turner syndrome. Similar patterns of short-term memory deficits were found in all three groups. There were no significant differences among the groups on computer measures of sustained attention and impulsivity. However, extreme variability of the attention and impulsivity scores for the Turner syndrome group may reflect atypical attention deficit disorder in some of these children.

Attention↗
PubMed1987

An examination of mental health services offered by cleft/craniofacial teams.

Questionnaire data about mental health services provided by teams for patients with cleft lip, cleft palate, or craniofacial anomalies were examined. The subjects were 195 directors of cleft/craniofacial teams. Descriptive analysis of the directors' responses included their teams' patient population, mental health representation, and intervention practices. Nurses and social workers were most frequently identified as the mental health specialists on the teams. Eighty percent of the directors stated that mental health intervention was important to patients and to teams. The type of service and the directors' ratings of the importance of psychosocial issues are presented. Research suggestions are provided.

Adolescent↗
PubMed1983

The dynamics of vertical eye movements in normal human subjects.

We studied the dynamics of horizontal and vertical slow eye movements (vestibular, optokinetic, pursuit, and visual-vestibular) in 10 normal human subjects. Several differences between horizontal and vertical eye movements were found. The time constant (time required for the slow-phase eye velocity to decay to 37% of the peak value) of vertical postrotatory nystagmus (PRN) was, on average, 50% as long as the time constant of horizontal PRN; the mean phase lead of per-rotatory nystagmus during low-frequency sinusoidal rotation in the vertical plane was approximately twice the mean phase lead of per-rotatory nystagmus at the same frequency in the horizontal plane. Vertical optokinetic after-nystagmus (OKAN) was minimal compared to horizontal OKAN. Asymmetries in the dynamics of vertical eye movements were also noted. The mean time constant of PRN with upward slow phases was consistently longer than the mean time constant of PRN with downward slow phases and vertical OKAN only occurred when the optokinetic stimulus moved upward. Upward pursuit was better than downward pursuit and upward slow phases of vestibular nystagmus were poorly inhibited with fixation while downward slow phases were normally inhibited.

Electrooculography↗
PubMed1978

School adjustment of children with observable disabilities.

This study investigated school behavior and achievement of children with mild degrees of observable physical disability. Children from two different disability types (cleft palate and cerebral palsy) were compared with each other and to a control group in order to determine potential similarities across disability types. Children (N = 78) from each of the two disability groups were individually matched to each other and to a normal control group (N = 39) by sex, IQ, socioeconomic status, age, and grade. They were compared on the basis of teachers' behavioral ratings and achievement test scores. All children attended regular public school classrooms. The two disability groups displayed significantly greater inhibition of impulse and lower educational achievement than did the controls. The implication of similar school adjustment across mild but observable subtypes is discussed.

Achievement↗