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Biomedical subjects

P Abbott

Publications and source records attributed to P Abbott.

9 recordsLinked to original sources

Placental opioid-enhancing factor (POEF): generalizability of effects.

A substance in amniotic fluid and placenta (POEF for Placental Opioid-Enhancing Factor) has been shown to enhance opiate- or opioid-mediated analgesia in rats. Recent studies have only touched on the generalizability of the phenomenon. The present studies further tested the generalizability of the POEF effect: they examined sex specificity of the mechanism; whether POEF activity exists in afterbirth material of species other than the rat; whether POEF activity exists in tissue other than afterbirth material; whether POEF activity could be demonstrated after injection rather than ingestion of afterbirth material; and whether POEF enhances all opioid-mediated phenomena. We found that (a) POEF is effective in male rats as well as in female rats; (b) POEF activity exists in human and dolphin afterbirth material; (c) ingestion of pregnant-rat liver does not produce enhancement of opioid-mediated analgesia; (d) POEF does not seem to be effective when amniotic fluid is injected either IP or SC; and (e) POEF does not modify morphine-induced hyperthermia.

Animals

Amniotic fluid ingestion before vaginal/cervical stimulation produces a dose-dependent enhancement of analgesia and blocks pseudopregnancy.

A substance in amniotic fluid (AF) and placenta has been shown to enhance analgesia produced by morphine, late pregnancy, footshock, and vaginal/cervical stimulation (VS). When morphine-induced analgesia was assessed previously, the degree of enhancement by ingestion of AF or placenta was found to be a function of the amount of analgesia being generated. We have extended these results to include the analgesia produced by VS. Analgesia induced by 75, 125, 175, or 225 g of vaginal/cervical pressure was measured in rats pretreated with 0.25 ml (by orogastric infusion) of either AF or saline. AF infusion enhanced the analgesia produced by 125 g VS, but did not affect the analgesia produced by 75, 175, or 225 g VS. Unexpectedly, we also found that infusion of AF shortly before the application of VS prevents VS-induced pseudopregnancy (PsP). Whereas the incidence of PsP following 75, 125, or 175 g VS was less than 19% and not statistically different for AF and saline pretreatments, the incidence of PsP after 225 g VS was 44% in saline-pretreated rats, but only 10% in AF-pretreated rats. Protection from the induction of pseudopregnancy, which could be caused by mechanical stimulation of the cervical area during delivery, may be an additional benefit of parturitional ingestion of placenta and amniotic fluid (placentophagia).

Afferent Pathways

Loss of heterozygosity for genes on 11p and the clinical course of patients with lung carcinoma.

Forty-five primary human lung carcinomas were evaluated for the loss of heterozygosity for genes on the short end of chromosome 11. Of 40 evaluable heterozygous cases, loss of the 11p genes c-H-ras and insulin was documented in nine cases (22%). The clinical parameters investigated for each patient included the disease stage at presentation, the presence of metastatic disease in either bronchial or mediastinal lymph nodes, and the presence of positive parietal pleural margins in the surgically resected specimen. There were no differences found with respect to these indicators when patients exhibiting the loss of heterozygosity were compared with those who did not have such genetic loss. In addition, when the clinical courses of the two patient groups were compared, there was no difference in survival. We conclude that the loss of heterozygosity for c-H-ras and insulin on 11p is a common finding in primary non-small cell human lung carcinomas but does not confer a more aggressive phenotype on these tumors. Although this genetic lesion may be important in the initial transformation of the cells to carcinoma, the available data for lung carcinoma are insufficient to prove causality.

Alleles

Amniotic-fluid ingestion by parturient rats enhances pregnancy-mediated analgesia.

Amniotic fluid and placenta contain a substance (POEF, for Placental Opioid-Enhancing Factor) that, when ingested, enhances opioid-mediated analgesia in nonpregnant rats; ingestion of the substance by rats not experiencing opioid-mediated analgesia, however, does not produce analgesia. It is highly likely that periparturitional analgesia-enhancement is a significant benefit of ingestion of the afterbirth (placentophagia) during delivery. Here we report that prepartum ingestion of amniotic fluid (via orogastric infusion) does indeed enhance the endogenous-opioid-mediated analgesia evident at the end of pregnancy and during delivery; that the degree of enhancement is greater with 0.75 ml than with 0.25 ml; and that the prepartum enhancement of analgesia can be blocked with the opioid antagonist naloxone.

Amniotic Fluid

Intractable neck pain.

A retrospective survey of 1,661 patients seen over a 10-year period at a pain clinic yielded 55 patients with intractable neck pain as the presenting complaint. In 89% there was an industrial or motor vehicle accident as the precipitating event, 78% were involved in legal proceedings relating to the accident, and in 87% the pain radiated to neighboring structures. Diagnostically, 36% had no physical signs, and cervical radiographs were normal for 46%. There was a high incidence of previous psychiatric treatment (53%) and major intrafamily problems (60%). Treatment mainly by psychotherapy or tricyclic antidepressants resulted in some benefit for 56% of patients. Legal compensation and change in occupation were not major factors influencing the outcome of treatment.

Accidents, Occupational

Anxiety, depression, and somatization in DSM-III hypochondriasis.

To assess the severity of distress and of somatization in hypochondriasis, the authors administered several validated self-rating scales of depression, anxiety, somatic symptoms, and anger/hostility to 21 psychiatric outpatients with the DSM-III diagnosis of hypochondriasis and to matched groups of other nonpsychotic psychiatric patients, family practice patients, and employees. Anxiety and somatic symptoms were highest in hypochondriacal patients; depression and anger/hostility did not differ from those of other psychiatric patients but were higher than in the other groups. The findings do not support the theory that hypochondriasis is a defense against anxiety or that it is a masked depression or depressive equivalent. The findings are consistent with the view that the interaction of severe anxiety and severe somatic symptoms is a common feature of the psychopathology of hypochondriasis.

Adult

Dose-dependent enhancement of morphine-induced analgesia by ingestion of amniotic fluid and placenta.

Ingestion of amniotic fluid and placenta by rats has been shown to enhance opioid-mediated analgesia. The present studies were designed to examine the effect of several doses and volumes of placenta and amniotic fluid on tail-flick latency in rats treated with 3 mg/kg morphine. The optimal dose of amniotic fluid was found to be 0.25 ml, although 0.50 and 1.0 ml also produced significant enhancement. Doses of 0.125 and 2 ml of amniotic fluid were ineffective, as was a dose of 0.25 ml diluted to 2 ml with saline. The optimal dose of placenta was found to be 1 placenta, although the resulting enhancement was not significantly greater than that produced by 025, 0.50, 2.0 or 4.0 placentas. Doses smaller than 0.25 placenta or larger than 4.0 placentas were ineffective. The most effective doses of amniotic fluid and placenta correspond to the amounts delivered with each pup during parturition.

Amniotic Fluid