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Biomedical subjects

R E Pettit

Publications and source records attributed to R E Pettit.

11 recordsLinked to original sources
PubMed1990

Effect of peanut tannin extracts on growth of Aspergillus parasiticus and aflatoxin production.

Twenty-three peanut (Arachis hypogaea L.) genotypes were evaluated for kernel resistance to Aspergillus parasiticus Spear. colonization and aflatoxin contamination when incubated under high relative humidity. Also, tannin-containing extracts from kernel coats (testae) and cotyledons of these genotypes were prepared and tested for their effect on A. parasiticus growth and aflatoxin production in vitro. The lowest degree of colonization, less than 30%, was noted in kernels from the genotypes, Toalson x UF 73-4022 (selections TX-798731 and TX-798736), A72118, SN 55-437, PI337409, and Florunner. Genotypes with low levels of colonization also had the lowest aflatoxin contamination. The coefficient of correlation between infection frequency and aflatoxin contamination was 0.66. Higher levels of tannins were detected in the testae (23.9-97.2 mg g tissue) compared to the cotyledons (0.17-0.82 mg g tissue). Some of the methanol-extracted and water-soluble tannin extracts from testae and cotyledons, when incorporated in yeast extract sucrose liquid medium (100 mg l), significantly inhibited A. parasiticus growth and reduced the levels of aflatoxin produced. There was no overall correlation between the peanut genotypes and the influence of tannin extracts on A parasiticus growth and aflatoxin production. However, correlations were higher for specific genotypes. For example, the coefficient of correlation between the ability of tannin extracts from testae of genotypes PI337409 and TX-798736 to inhibit aflatoxin production was 0.93 and 0.85 respectively.

Aflatoxins↗
PubMed1987

Pyridoxine dependency seizures: report of a case with unusual features.

Pyridoxine dependency is a rare cause of neonatal seizures. Newborns with this disorder are often hyperirritable and fail to respond to the usual anticonvulsants. The diagnosis is established by cessation of seizures after the administration of parenteral pyridoxine. Reported is a case of pyridoxine dependency that illustrates several problems in management. The amount of pyridoxine required to control seizures is variable and may exceed 100 mg per day. The electroencephalogram (EEG) may not change significantly during the initiation of therapy. During intercurrent illnesses, parenteral pyridoxine may need to be given. Additional pyridoxine may be needed even when the EEG is normal. Treatment should continue indefinitely.

Dose-Response Relationship, Drug↗
PubMed1986

Leukocyte granulation abnormality associated with normal neutrophil function and neurologic impairment.

This article describes studies of two unrelated patients, ages 5.5 and 26 years, with leukocyte granulation abnormalities similar to those in the Chediak-Higashi syndrome. Both patients presented with neurologic manifestations characterized by psychomotor impairment, but neither had any evidence of oculocutaneous albinism, photophobia, or increased susceptibility to pyogenic infection. The leukocytes were studied for cytochemical, ultrastructural, ultrastructural cytochemical, and functional characteristics. Abnormal granules were present in neutrophils, eosinophils, basophils, monocytes, and lymphocytes; in the neutrophil series the abnormalities involved both the azurophilic and specific granules. On ultrastructural examination, the abnormal granules in the neutrophils were found to result from fusion of both peroxidase-positive and peroxidase-negative granules. Large numbers of normal granules were also present. The abnormal large granules in the eosinophils and basophils were the result of fusion of normal granules. The neutrophil function studies showed normal chemotaxis, chemiluminescence, bactericidal activity, and nitro-blue tetrazolium reduction. The normal neutrophil function studies were paralleled by the clinical histories in that neither patient had a history of severe infectious episodes.

Adult↗
PubMed1984

Chédiak-Higashi syndrome. Neurologic appearance.

A 25-year-old man was first seen with a neurologic disorder that resembled a spinocerebellar degeneration and parkinsonism. A peripheral smear revealed the characteristic peroxidase-positive panleukocytic granules associated with the Chédiak-Higashi syndrome. He did not have any associated oculocutaneous abnormalities. The Chédiak-Higashi syndrome may appear primarily with neurologic dysfunction and should be considered in a differential diagnosis of children and young adults first seen with a spinocerebellar degeneration or movement disorder.

Adult↗
PubMed1980

Benign familial neonatal seizures.

Five family members in three successive generations experienced convulsions as newborns. One died during a cyanotic spell. The remaining four are developmentally and neurologically normal, although three continue to have seizure disorders as adults. No underlying inborn error of metabolism has been identified. This family appears to have a familial epilepsy beginning at birth that is transmitted as an autosomal dominant trait.

Electroencephalography↗
PubMed1980

Macrocephaly with head growth parallel to normal growth pattern: neurological, developmental, and computerized tomography findings in full-term infants.

Fifteen infants with macrocephaly had a head growth pattern parallel to 2 SDs above normal. In eight patients with initial and subsequent normal findings on neurological and developmental examinations, computerized tomography (CT) showed slight ventricular dilation and increased width of the subarachnoid space anteriorly. The other seven patients had abnormal results from neurological or developmental examinations. The CT findings in two were similar to those in the first group; in four, other abnormalities were observed; and one had a normal scan. None of the 15 infants required shunting. In infants with this head growth pattern, a similar CT scan with ventricular dilation and widened subarachnoid space could be found in patients with normal or abnormal results from neurological and developmental examinations. Those infants with this CT scan pattern and normal neurological and developmental findings appear to have a benign condition.

Cephalometry↗
PubMed1971

Influence of fungicides and irrigation practice on aflatoxin in peantus before digging.

Peanuts grown under dryland conditions where drought stress occurred accumulated more aflatoxin before digging than peanuts grown under irrigation. Kernels became more susceptible to Aspergillus flavus and A. parasiticus invasion when the soil moisture in the pod zone approached levels at which moisture moved from the pod into the soil and the kernel moisture dropped below 31%. Isolation frequencies of these aspergilli from fresh-dug kernels were lowest in 1968 (maximum of 3%). In 1967 and 1969, maximum percentages of 100 and 74, respectively, were noted. Kernel infestation was correlated with degree of aflatoxin contamination. Dryland fresh-dug kernels contained a maximum of 35,800 parts per billion aflatoxin while a maximum of 50 parts per billion was detected in kernels from irrigated plots. In 1969 A. flavus infestation was as high as 59% in peanuts from irrigated plots; however, no aflatoxin was detected. Absence of aflatoxin in these samples is attributed to the higher kernel moisture content which reduced the aflatoxin-producing potential of A. flavus. Statistical analysis of the data revealed no significant differences in degree of fungal infestation, production levels, and grade factors between any fungicide treatments.

Acetone↗
PubMed1968

Factors influencing aflatoxin accumulation in peanut kernels and the associated mycoflora.

Accumulation of aflatoxin in Spanish peanut kernel samples from different geographical areas in Texas during 1966, as detected by the thin-layer chromatographic method, was relatively low. Analysis of samples obtained from growers using artificial drying equipment (forced air and supplemental heat), when windrow conditions were unfavorable for rapid drying, suggests that this practice reduces the possibility of aflatoxin accumulation. In general, peanuts harvested from land planted to peanuts the previous year were more highly infested with fungi and contained more aflatoxin than peanuts grown on land planted with rye, oats, melons, or potatoes the previous year. Aflatoxin incidence tended to decrease from south to north Texas. These findings verify previous research observations that moist tropical climates are conducive to fungal infestation and aflatoxin accumulation. Detection of aflatoxin in sound mature kernels (kernels screened for minimal size) indicates that the practice of screening for removal of small immature kernels and removal of obviously damaged kernels does not completely eliminate aflatoxin contamination.

Aflatoxins↗