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Biomedical subjects

R G Curless

Publications and source records attributed to R G Curless.

At least 55 records · Page 3Linked to original sources
PubMed1977

Congenital fiber type disproportion in identical twins.

Eighteen-month-old identical twins with the muscle histological characteristics of congenital fiber type disproportion are reported. The fiber typing system of pH-dependent adenosine triphosphatase was used to analyze the size and percentage of type 1, 2A, and 2B fibers in muscle tissue obtained by needle biopsy. Both twins had significantly larger type 2 than type 1 fibers, with 2B fibers representing the largest type. One patient also had type 1 predominance at the expense of a reduction in 2B (2B deficiency). The probands as well as other family members had transient delayed motor development, macrocephaly, and normal intelligence. A biopsy obtained from 1 of these family members failed to demonstrate a similar histological abnormality. The disorder is nonprogressive in this family, as evidenced by minimal disability in the older members and gradual improvement in the probands.

Biopsy, Needle↗
PubMed1977

Fingerprint inclusions. Ultrastructural demonstration of muscle fiber type specificity.

Fingerprint inclusions were identified in the skeletal muscle of a child with severe hypotonia. The mean Z-line and M-line widths from each of 19 muscle fibers containing the fingerprint inclusions were calculated. The mean Z-line widths were 85-99 nm, and the mean M-line widths were 75-101 nm. According to out present system of fiber typing, all of these fibers would be classified as Type I. The possible pathogenesis and fiber type specificity of the fingerprint inclusion is discussed.

Child, Preschool↗
PubMed1977

Brain and spinal cord lesions in the newborn rat.

Previous studies involving the induction of central nervous system lesions in animals have required complex, expensive equipment including sterotaxis and an operating microscope. This study describes a technique for producing telencephalic (forebrain) lesions in the developing rat by the use of copper wire. In addition, a nonvisual method of producing spinal cord transections in the young rat is discussed. Both techniques have a high succes rate and minimal mortality.

Animals↗
PubMed1976

Concentric laminated bodies. Ultrastructural demonstration of muscle fiber type specificity.

Concentric laminated bodies were identified in the skeletal muscle of 3 children affected by muscle weakness and hypotonia with probable cerebral involvement. The mean Z-line and M-line widths from each of 11 muscle fibers containing the concentric laminated bodies were calculated. The mean Z-line widths were 61-81 nm and the mean M-line widths from 7 out of 11 fibers were 54-65 nm. According to our present system of fiber typing, the majority of these fibers would be classified as subtype IIB. The possible pathogenesis and fiber type specificity of the concentric laminated body is discussed.

Child, Preschool↗
PubMed1976

Phenytoin kinetics in children.

Previous studies have shown the importance of phenytoin kinetics in the management of adult patients with seizure disorders. The long half-life in adults makes single daily dosing realistic in terms of blood levels and anticonvulsant effectiveness. This report shows a wide range in both half-lives and volumes of distribution of phenytoin in 11 children (ages 6 months to 6 years) with seizure disorders. Ten of these patients have very short phenytoin half-lives (1.2 to 6.7 hours). The data strongly suggest that current recommendations for phenytoin dosage regimens in adults cannot necessarily be used in children. Blood levels must be followed closely in this age group to determine the required dosage and dose interval.

Age Factors↗
PubMed1976

Developmental patterns of rat muscle histochemistry.

A developmental progression of histochemical fiber typing is demonstrated in normal rat soleus muscle. By utilizing the acid lability of ATPase, the type II fibres are subdivided into type IIA, IIB and IIC. No IIB fibers are present in the newborn or adult rat soleus. In the 1-day-old animal 90% of the fibers can be differentiated into type I and II with all of the type II's demonstrating IIC characteristics. Only type I and IIC fibers are present until 18 days, when poorly differentiated IIA fibers first appear and gradually become the predominant type II fiber at the expense of IIC's. Further analysis documents the sequence of disappearance of myotubues from up to 80% of all fibers in the 1-day-old to less than 1% between 15 and 18 days. An analysis of the progression of fiber size according to type is presented.

Adenosine Triphosphatases↗
PubMed1976

Headache in classical hemophilia. The risk of diagnostic procedures.

Headache in a hemophiliac poses a major problem. The fact that at least half of hemophiliacs with proven intracranial hemorrhage present with a headache but no preexisting injury, requires an aggressive approach to the management of these patients. Recent articles point out successful instances of craniotomy in hemophilia, but relatively few hemophiliacs with headaches progress to that stage. We have reviewed the literature and added three cases in an attempt to establish the risk of spinal puncture and cerebral angiography in the evaluation of these patients. The data presented suggests that with replacement therapy and attention to angiographic technique, both procedures may be performed with minimal risk.

Cerebral Angiography↗
PubMed1975

Ultrastructural fiber typing in normal and diseased human muscle.

The differential staining of the 3 fiber types for oxidative enzyme activity at the histochemical level provides the basis of their identification at the ultrastructural level. Type I fibers have the largest and most numerous mitochondria, the Type IIA smaller and less numerous mitochondria, and Type IIB have the smallest and least numerous mitochondria as studied in 4 patients without neuromuscular disease. Type I fibers could be distinguished from Type II fibers on the basis of mean Z-line width and IIA fibers could be distinguished from IIB fibers on the basis of mean M-line width. Type I fibers had wide Z-lines (95 nm) and wide M-lines (89 nm), Type IIA had narrow Z-lines (74 nm) and wide M-lines (79 nm) and Type IIB fibers had narrow Z-lines (69 nm) and narrow M-lines (60 nm). This system of fiber typing based on relative Z-line and M-line widths was applied to several abnormal muscle biopsies each of which showed a deficiency in at least 1 of the major histochemical fiber types. In each case, the same deficiency was revealed at the ultrastructural level by measuring the relative Z-line and M-line widths of the remaining fiber types.

Adenosine Triphosphatases↗
PubMed1975

Needle biopsies of muscle in infants for diagnosis and research.

The results of needle biopsies of muscle in 14 infants (age-range four months to 3 years 3 months) with marked hypotonia are presented. In adults, needle biopsies of muscle have been used to aid in the diagnosis of neuromuscular disorders, with considerable success. The simplicity of the method and the high quality of the samples obtained in the present study suggest that further evaluation of the technique in infants and small children is warranted, and that needle biopsy may in future take precedence over the more commonly used open technique.

Biopsy, Needle↗
PubMedDate not supplied

Ambulatory EEG recordings in children with infrequent seizures.

Twenty-one children, ages 1-15 years, were selected for outpatient ambulatory electroencephalographic (AEEG) monitoring on the basis of infrequent seizures without therapy, normal routine EEGs, and normal neurologic/developmental examinations. Technically satisfactory recordings were obtained in all patients; recording time consisted of 24, 22, and 6 hours for 15, 4, and 2 patients, respectively. Eighteen patients were not receiving antiepileptic drug therapy at AEEG. The follow-up intervals after the AEEG ranged from 4-20 months. Only 2 patients had epileptiform AEEGs. Of the remaining 19 with nonepileptiform records, 10 were seizure free without antiepileptic drug therapy, but 9 developed additional seizures which required treatment.

Adolescent↗
PubMedDate not supplied

Central nervous system tuberculosis in children.

The incidence of tuberculosis in the United States is increasing in all age groups; 5% of all of these patients have central nervous system involvement. We studied childhood central nervous system tuberculosis between 1979 and 1989 and reviewed the literature for patients up to 14 years of age. The small number of patients reported in this country results in delayed diagnoses because of reduced awareness. Cranial computed tomography within 1 week of initial symptoms may reveal basilar enhancement, hydrocephalus, or infarction. When combined with cerebrospinal fluid findings atypical for common bacterial infection, these radiographic findings support the prompt initiation of antituberculous therapy. Prophylactic considerations are also discussed.

Central Nervous System Diseases↗