Morphological abnormalities

Deficiency. Macrocytic anemia, megaloblastic anemia, and neurological symptoms characterize vitamin B 2 deficiency. Alterations in hematopoiesis occur because of the high requirement for vitamin B 2 for normal DNA repHcation necessary to sustain the rapid turnover of the erythrocytes. Abnormal DNA repHcation secondary to vitamin B 2 deficiency produces a defect in the nuclear maturational process of committed hematopoietic stem cells. As a result, the erythrocytes are either morphologically abnormal or die during development. 

Morphological abnormalities in developing eggs of Limnaea palustris at 0.230mg/L... 

Measurements of regional cerebral blood flow by PET and of cerebral perfusion by SPECT often detect functional abnormalities before CT or MRI identifies morphological abnormalities 945 The PET method is a valuable tool for the estimation of regional glucose and oxygen metabolic rates and cerebral blood flow 946 PET and SPECT combined with principles of receptor binding permit imaging of receptors in the intact brain 946... 

Morphological abnormalities, both positive and negative phototaxis suppressed 29... 

Pyrethroids produce no common teratogenic effects in a particular species based on similarity in structure or mode of insecticidal action. In most of the animal studies with pyrethroids, no increased incidences of morphological abnormalities were... 

The lack of G6PD activity means that the production of NADPH is compromised, oxidized glutathione (GSSG) cannot be reduced (to GSH) and the red cells show morphological abnormalities leading to lysis. 

In an attempt to influence flavor characteristics, CHS antisense and overexpression constructs were introduced into grapefruit by Agrobacterium tumefaciens [16, 59]. CHS overexpression constructs were shown to lead to morphological abnormalities and frequently to death, while a number of CHS antisense constructs resulted in a statistically significant reduction in flavonoid content in the transgenic plants even though there was a large variation in the flavonoid concentration [16]. 

Noiri et al. used AS-ODN to inhibit production of inducible nitric oxide synthase (INOS) in an attempt to prevent NO production in an ischaemic kidney. A single intravenous injection of iNOS AS-ODN attenuated acute renal failure and reduced the morphological abnormalities [129],... 

A two-generational study in pregnant rats exposed to 538 ppm 1,4-dichlorobenzene via inhalation produced decreased survival and decreased body weights in Fj pups (Tyl and Neeper-Bradley 1989). Murthy et al. (1987) reported morphologically abnormal sperm in rats exposed to 800 mg/kg/day by intraperitoneal injection. There are no studies that report transgenerational effects of exposure to... 

Functional disturbances in spermatogenesis and morphologic abnormalities of sperm were observed among workers occupationally exposed to 0.28 and 1.94ppm chloroprene. A threefold excess of miscarriages in the wives of these workers also was reported. 

Daily oral doses of 4.3, 43, or 432mg/kg to rats on days 6-15 of gestation caused abnormalities in 50%, 93%, and 100% of the animals. Major malformations, including micromelia, vertebral opening, and skull defects, were observed at the highest dose, whereas only skeletal variations occurred at 4.3 mg/kg. Applied to the skin of pregnant rats 1.4ml/kg caused marked maternal toxicity and morphologic abnormalities in the fetuses at... 

Beltrame D, Giavini E (1990) Morphological abnormalities in experimental teratology need for a standardization of current terminology. Cong Anom 30(3) 187-195... 

The experienced reproductive toxicologist understands the normal variability of the various study endpoints, e.g., the prevalence of clusters of cleft palate in the control population of mice. He is also familiar with the relative sensitivity of the various parameters to toxicological insult, e.g., frequent reactive increases in liver weight due to metabolic activation versus the relative stability of brain weight, which is rarely influenced by systemic toxicity. An understanding of the relationship between the endpoints is also important, e.g., an increase in the incidence of morphological abnormalities is more likely to be... 

Bechter R Teriouw GDC (1993) Strain differences in the control incidences of morphological abnormalities in the rat whole embryo culture. Toxicol In Vitro, 7(Suppl 1) 281-284. 

Caprolactam treatment in vivo did not increase DNA single-strand breaks in hepatocytes or unscheduled DNA synthesis in spermatocytes of rats, did not induce sister chromatid exchanges, micronuclei or chromosomal aberrations in mouse bone marrow and did not induce morphological abnormalities in mouse sperm. Inconclusive results were reported in two mouse spot test studies for gene mutations. 

Washington, W.J., Murthy, R.C., Doye, A., Eugene, K., Brown, D. Bradley, I. (1983) Induction of morphologically abnormal sperm in rats exposed to o-xylene. Arch. Androl., 11, 233-237... 

These studies offer a new model of concomitant behavioral, chemical, and morphological abnormalities associated with a defined Insult at a critical period 1n dendritic development. This model may have some special Importance 1n relation to minimal brain dysfunctions, particularly since no blood-brain barrier protects the fetal brain from antibodies 1n the maternal circulation. 

The impetus for the developmental studies came not from embryology but from clinical observations on the postnatal organism, on metabolic problems frequently seen in newborn children. They occurred in the absence of genetic or morphological abnormalities, were often transient, indicated defects in hepatic functions, and had a higher incidence in premature than in term infants. For these reasons, Dawkins(4) suggested that several important hepatic enzymes are acquired only shortly before or after term, so that the newborn is not immediately ready to take over functions which, like detoxifixations, had been carried out by the maternal liver. 

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