Reproductive deficit

Knockout of the prolactin receptor, rather than knockout of prolactin, is necessary to explore the role of the hormone and its receptor in maternal behavior because several molecules other than prolactin, including growth hormone (GH) and placental lactogens, may stimulate the prolactin receptor. Disruption of the prolactin receptor gene in a mouse model has allowed for assessment of phenotypes associated with partial and complete prolactin receptor deficits (Goffin et ah, 1999). Prolactin receptor knockout mice have severe reproductive deficits. Heterozygous mothers (receptor —/+) were also unable to lactate (Bridges, 1998). 

Technical linuron is highly toxic to aquatic invertebrates, while the formulated product is less toxic. Linuron was highly toxic to sheepshead minnow and moderately toxic to eastern oyster and mysid shrimp. Linuron is practically nontoxic to honeybees. Reproductive deficits have been noted in birds treated with linuron. 

Co deficit Everywhere Low content of Co in Podsoluvisols, Podzols, Arenosols and Histosols. The average Co content in plant species is < 5 ppb The decrease of Co content in tissues decrease of vitamin BJ2 in liver (tr.—130 ppm), in tissue (tr.—0.05 ppm), in milk (tr.—3 ppm). Synthesis of vitamin Bi2 and protein is weakened. Cobalt-deficiency and Bj2 vitamin-deficiency. The number of animal diseases is decreasing in raw sheep —cattle — pigs and horses. Low meat and wool productivity and reproduction... 

Adverse reproductive effects have been observed in animals fed PCB in the diet. Fetal resorptions were common, and dose-related incidences of terata were found in pups and piglets when females were fed Arochlor 1254 at Img/kg/day or more. Long-term low-level maternal exposure of rats before breeding and throughout gestation and lactation caused permanent hearing deficits, decreased serum thyroid hormones, and reproductive effects. PCBs have been observed in human cord blood and in tissues of newborn humans and animals. ... 

In human beings and most mammals, affiliation is an essential part of the life process, as it is necessary for both reproduction and survival. There are nonetheless instances in nature of profound lack of affiliative behavior. For example, children with autism spectrum disorders have significant difficulties in social skills, including lack of positive reinforcement from social interaction, poor eye gaze, impairment in social interactions, difficulties in attachment, and difficulties in nonverbal and, often, verbal communication. Deficits of this kind have led us to the study of the neurobiology underlying attachment and affiliation. 

Oxytocin typically has a facilitative effect on affiliative behaviors (Witt et ah, 1992), including parental and reproductive behaviors and infant-mother attachment. Oxytocin facilitates social memory, with knockout mice displaying social memory deficits it facilitates conditioning to maternal-related olfactory cues (Nelson and Panksepp, 1996). 

Lead Inorganic lead oxides and salts Gastrointestinal, respiratory Soft tissues redistributed to skeleton (> 90% of adult body burden) CNS deficits peripheral neuropathy anemia nephropathy hypertension reproductive toxicity Inhibits enzymes interferes with essential cations alters membrane structure Renal (major) feces and breast milk (minor)... 

Methylmercury intoxication affects mainly the central nervous system and results in paresthesias, ataxia, hearing impairment, dysarthria, and progressive constriction of the visual fields. Signs and symptoms of methylmercury intoxication may first appear several weeks or months after exposure begins. Methylmercury is a reproductive toxin. High-dose prenatal exposure to methylmercury may produce mental retardation and a cerebral palsy-like syndrome in the offspring. Low-level prenatal exposures to methylmercury have been associated with a risk of subclinical neurodevelopmental deficits. 

Reproductive Effects. The two studies of developmental effects (see Developmental Effects) included observations of maternal toxicity, maternal deficits in weight gain were present in mice and rats and mice exhibited an increased rate of resorptions. Maternal toxicity undoubtedly was the most important contributing factor in producing the developmental effects. The relevance of the findings to humans is not clear. 

In comparisons of numbers of children, men who did not respond to the question on children were assumed to have had no children. Most men who failed to respond to this item had never been married. Table 26 shows the numbers of children reported by men tested only with anticholinergics and with anticholinergics and other chemicals. The deficits in numbers of children of those exposed only to anticholinergics and those exposed to anticholinergics and other chemicals were the same 1.81 children per respondent compared with an expectation of 2.01 children per respondent, based on the age-specific NCT-group reproduction rates. The expected number of men with given family sizes was also estimated on the basis of the age-specific reproduction... 

Reviews of the results from the reproductive toxicity testing for the approved monoclonal antibody biopharmaceuticals have shown very few incidences of harm to fetuses. The only notable effects that have been observed are hematologic changes in macaque fetuses exposed to natalizumab, skeletal abnormalities in rabbit fetuses exposed to bevacizumab, and immunological deficits in mice exposed to the efalizumab murine surrogate. In each of these examples the effects seen in the fetuses were predicable based on effects seen in the adult animals. 

Chronic exposure to maneb has been related to reproductive, embryotoxic teratogenic, and neurotoxic effects. Although the toxicity associated with maneb exposure is low, it has been shown that in combination with other toxicants such as metals, other fungicides and herbicides the effects of maneb may be more pronounced, leading to more severe deficits. 

Radioactive Strontium. Numerous oral exposure have demonstrated the enhanced risk of reproductive effects and cancer in animals exposed to radiostrontium in utero or during lactation. At the higher levels used in injection studies, teratogenic effects were observed on bone development. The possibility of neurological deficits from gestational exposure to radioactive strontium, resulting from radiostrontium incorporation into the cranium and subsequent irradiation of adjacent brain tissue, should be explored. The toxicokinetic and bioavailability issues mentioned in the previous section on Stable Strontium apply to radioactive strontium. Low-level exposure studies should be conducted to evaluate possible impairment of immune function, which results from irradiation of bone marrow by radiostrontium incorporated into bone and which has been observed in animal studies at higher levels. ... 

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