PubMed Health⌕ Search

Biomedical subjects

V Pratt

Publications and source records attributed to V Pratt.

8 recordsLinked to original sources
PubMed1997

Proteolipid protein is necessary in peripheral as well as central myelin.

Alternative products of the proteolipid protein gene (PLP), proteolipid protein (PLP) and DM20, are major components of compact myelin in the central nervous system, but quantitatively minor constituents of Schwann cells. A family with a null allele of PLP has a less severe CNS phenotype than those with other types of PLP mutations. Moreover, individuals with PLP null mutations have a demyelinating peripheral neuropathy, not seen with other PLP mutations of humans or animals. Direct analysis of normal peripheral nerve demonstrates that PLP is localized to compact myelin. This and the clinical and pathologic observations of the PLP null phenotype indicate that PLP/DM20 is necessary for proper myelin function both in the central and peripheral nervous systems.

Adolescent↗
PubMed1996

Goethe's Archetype and the romantic concept of the self.

This paper attempts to illuminate Goethe's concept of an archetype by setting it alongside the concept of the self that was being articulated at the same time, also by writers of the Romantic movement. The Romantic concept of the self expresses a new concept of the self as a 'core' plus an expression of the core: and it is the same 'core plus expression' idea that is embodied in the Goethean archetype. Goethe's archetype is not simply a 'plan'. It is a kind of agent at the heart of a thing, striving for self expression, and to this end driving the thing's development. Both Romantic self and archetype reflect the wider attempt to reinstate the concept of action in our understanding of things and happenings in general. The root idea of there being at the heart of a living thing an agent pursuing a goal remains in the modern concept of the organism.

Biology↗
PubMed1996

An association between precocious puberty and fragile X syndrome?

STUDY OBJECTIVE: To determine the FMR1 gene status in a 10-year, 10-month-old girl with a history of precocious puberty and a family history of fragile X syndrome. DESIGN: Case report. SETTING: The outpatient facility of the Division of Adolescent Medicine and the Division of Genetic and Metabolic Disorders at Children's Hospital of Michigan and the Medical Genetics and Birth Defects Center of Henry Ford Hospital, Detroit, Michigan. PARTICIPANT: A 10-year, 10-month-old girl with a history of precocious puberty. INTERVENTION: Evaluation for menorraghia, DNA extraction, and fragile X gene analysis of blood samples from the patient and her mother. MAIN OUTCOME MEASURES: Identification of a full mutation in the FMR1 gene. RESULTS: Southern blot analysis of the FMR1 gene identified a full mutation in the daughter with approximately 750 repeats of the CGG sequence. Methylation studies showed that the full mutation was completely methylated. FMR1 DNA studies on her mother identified a premutation of approximately 100 repeats. CONCLUSIONS: This report identifies a young girl with a history of precocious puberty and fragile X syndrome. It is also the first report of molecular genetic FMR1 studies in a female with precocious puberty. A possible association between the two conditions is suggested and warrants further investigation.

Blotting, Southern↗
PubMed1991

Diverse backmutations at an ochre defect in the tyrA gene sequence of E. coli B/r.

A DNA fragment including most of the tyrA gene from E. coli B/r strain WU (Tyr-, Leu-) was amplified in vitro by polymerase chain reaction. The sequence was determined, first, for essentially all of the fragment to locate an ochre nonsense defect, and second, repeatedly for a region of the fragment from several independent isolates containing backmutations at the ochre codon (spontaneous and UV-induced). There were 20 single base differences in the tyrA gene region from the analogous wild-type E. coli K12 sequence: an ochre codon at amino acid position 161, 18 silent changes (1 at the first codon base and 17 at the third) and one replacement of valine by alanine. Different backmutations at the ochre codon encoded lysine, glutamine, glutamic acid, leucine, cysteine, phenylalanine, serine or tyrosine. The diversities of base substitutions at the ochre codon after UV mutagenesis or after mutagenesis where targeting by dimers was reduced or eliminated (after photoreversal of irradiated cells treated with nalidixic acid to induce SOS functions or after UV mutagenesis of cells containing amplified DNA photolyase) were similar (with two notable exceptions). The overall differences between the gene sequences for E. coli K12 or B/r seemed consistent with the neutral theory of molecular evolution.

Base Sequence↗
PubMed1991

Classification of plasma cortisol patterns in normal subjects and in Cushing's syndrome.

The 24-h pattern of half-hourly sampled plasma cortisol in normal human subjects shows a 24-h (circadian) period, which may be variably distorted in patients who suffer from autonomous hypercortisolism (Cushing's syndrome). We have developed a pattern recognition system for computer classification of cortisol time series into the normal class and subclasses of Cushing's syndrome with different etiology ("pituitary" designating pituitary tumor, "adrenal" designating adrenal tumor, and "ectopic" designating tumor elsewhere). Discriminatory features were extracted from Fourier analysis and Karhunen-Loeve expansion coefficients of cortisol time series. Decision functions were trained by the LMSE algorithm and tested by the jack-knife test procedure on a data-base of 90 normal and patient patterns. The classification accuracy for normal, "pituitary," "adrenal," and "ectopic" classes was 100, 98.1, 98.3, and 100%, respectively. Hence this pattern recognition system may be useful as an aid in the differential diagnosis of Cushing's syndrome.

Algorithms↗