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Biomedical subjects

I Stevenson

Publications and source records attributed to I Stevenson.

At least 37 records · Page 2Linked to original sources
PubMed1985

Protoplast formation from submerged mycelium and from spore germinants of Streptomyces coelicolor.

Stages in the formation of protoplasts from S. coelicolor strain A3(2) have been studied by transmission electron microscopy. Protoplasts liberated from submerged mycelial growth were variable in size and were released when digestion of the cell wall by lysozyme had completely or almost completely taken place. Protoplasts did not fully adopt the typical rounded shape until after release. A single region of cytoplasm gave rise to more than one protoplast unit. Protoplasts released from spore germinants escaped from the tip of the germ tube, which was the region of the cell wall most susceptible to digestion. Protoplasts derived from spore germinants were more consistent in size and rounded up more rapidly. If a cross-wall had formed in a germinant then it gave rise to separate protoplasts from each cellular compartment. Protoplasts of either type contained a single DNA region. These studies give an indication of the cellular organization of a streptomycete colony, which can be visualized as a multinucleated assemblage of cellular units in a common cytoplasm. The assembly of units separates into a number of protoplasts on digestion of the cell wall.

Microscopy, Electron↗
PubMed1983

American children who claim to remember previous lives.

An unknown number of American children claim to remember previous lives. In this paper data of 79 such children are analyzed and compared with data from a larger number of cases in India. Few American children of these cases make verifiable statements, and those who do nearly always speak about the lives of deceased members of their own families. In this feature, American cases differ from Indian ones, in which the children usually speak of the lives of deceased persons in another family and often in another community. Indian children also frequently make verifiable statements about the lives of such persons. In some other respects, however, such as the age of first speaking about the previous lives, the content of the statements they make, and related unusual behavior, American subjects closely resemble ones in India. Although many of the American cases may derive from fantasies, a wish-fulfilling motive or obvious gain for the child is not discernible in most of them. Nor do the cases resemble in their form fantasies of imaginary playmates. Some American cases of this type occur in families already believing in reincarnation, but many others do not. In these families the child's statements about a previous life are often puzzling and even alarming to his or her parents. The child is sometimes involved in conflict over the apparent memories with members of his or her family.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1983

Do we need a new word to supplement "hallucination"?

The word "hallucination" was used originally (and with etymological correctness) to refer to the unshared sensory experiences of persons who are mentally ill. However, many persons who are not mentally ill also have unshared sensory experiences. A few of these convey information paranormally, but the longstanding association of "hallucination" with mental illness inhibits many persons who have such experiences from reporting them so that they can be studied. The author suggests a new word, "idiophany," to designate all unshared sensory experiences. The word "hallucination" could then be restricted, as it originally was, to the unshared sensory experiences of the mentally ill.

Hallucinations↗
PubMed1980

Influence of surgery on plasma propranolol levels and protein binding.

The influence of surgery and anesthesia on perioperative plasma propranolol levels was studied in 25 hyperthyroid and five euthyroid patients undergoing thyroidectomy. Propranolol levels fell markedly after surgery as a consequence of poor drug administration in the immediate postoperative period due largely to patients' nausea and inability to swallow. Propranolol was not detectable in the plasma of three hyperthyroid patients 8 hr after surgery. When propranolol was given through a nasogastric tube, propranolol levels were satisfactory throughout. Compared with preoperative levels, in all patients there was a two- to threefold rise in total and free propranolol levels 24 hr after surgery, suggesting decreased hepatic clearance of propranolol. The degree of plasma protein binding of propranolol had also increased on the day after surgery, leading to a 30% reduction in propranolol free fraction. Surgery and anesthesia greatly influence the handling of propranolol in the perioperative period.

Absorption↗
PubMed1980

The phenomenology of near-death experiences.

The authors studied retrospectively 78 reports of "near-death experiences using subjects narratives and questionnaires, interviews, and medical records. Prior experiences suggestive of transcendence of death were more common among these subjects than among control populations, but prior experiences suggestive of extrasensory phenomena were less common. Subsequent changes in attitudes were more common than among subjects in other studies who had had psychic experiences. The influence of cultural and psychological factors, sensory deprivation, and reflex adaptive responses to stress explain some but not all of the features of near-death experiences. Their potential value to our conceptualization of dying and to suicide prevention and the care of the terminally ill justifies further investigation.

Adolescent↗
PubMed1980

Propranolol dosage in thyrotoxicosis.

Eighteen thyrotoxic patients receiving chronic treatment with propranolol (160 mg/day) were studied to determine the relationship between plasma propranolol concentration and drug effect. There was a considerable interindividual variability in both the plasma propranolol steady state concentration and the degree of beta-adrenergic blockade. The plasma propranolol steady state concentration correlated significantly with both beta-adrenergic blockage and weight change but not with the degree of subjective improvement. In a group of 40 patients, including 10 severely thyrotoxic patients, who had the dosage of propranolol titrated objectively preoperatively to bring about a greater than 25% reduction in exercise heart rate at the end of a dosage interval, no case of thyroid storm was encountered. Many patients, the younger and severely thyrotoxic in particular, require doses in excess of 160 mg/day to achieve this degree of beta-adrenergic blockade.

Adolescent↗
PubMed1977

Ribonucleic acid stimulation of mammalian liver nuclear-envelope nucleoside triphosphatase. A possible enzymic marker for the nuclear envelope.

1. The specific activity of rat and pig liver nuclear-envelope nucleoside triphosphatase (EC 3.6.1.3) decreases when the system is depleted of RNA. The activity can be restored by adding high concentrations of yeast RNA to the assay medium. 2. Exogenous RNA also increases the activity of the enzyme in control envelopes (not RNA-depleted). The effect appears to be largely specific for poly(A) and poly(G); it is not stimulated by rRNA or tRNA preparations, ribonuclease-hydrolysed RNA, AMP, or double- or single-stranded DNA. 3. Inhibitors of the enzyme, in concentrations at which half-maximal inhibition of the enzyme is achieved, do not affect the percentage stimulation of the enzyme by yeast RNA. 4. The simulation is abolished by the inclusion of 150 mM-KCl or -NaCl in the assay medium, but not by increasing the assay pH to 8.5. 5. The results are discussed in the light of the possible role of the nucleoside triphosphatase in vivo in nucleo-cytoplasmic ribonucleoprotein translocation. 6. It is proposed that poly(G)-stimulated Mg2+-activated adenosine triphosphatase activity should be adopted as an enzymic marker for the nuclear envelope.

Adenosine Triphosphatases↗
PubMed1977

The explanatory value of the idea of reincarnation.

The idea of reincarnation is presented as having considerable explanatory value for several features of human personality and biology that currently accepted theories do not adequately clarify. Reincarnation is not offered as a substitute for present knowledge derived from genetics and understanding of environmental influences; it may, however, usefully supplement such knowledge. The present paper does not present evidence from cases suggestive of reincarnation. It does, however, cite cases of subjects who have claimed to remember previous lives, most of whose statements have been verified in the course of detailed investigations. For each case, a reference is provided to a detailed published case report furnishing the evidence in that case. The idea of reincarnation may contribute to an improved understanding of such diverse matters as: phobias and philias of childhood; skills not learned in early life; abnormalities of child-parent relationships; vendettas and bellicose nationalism; childhood sexuality and gender identity confusion; birthmarks, congenital deformities, and internal diseases; differences between members of monozygotic twin pairs; and abnormal appetites during pregnancy. Empirical studies of cases of the reincarnation type have so far not provided any evidence that justifies using reincarnation as an explanation for the occurrence of child prodigies of the large inequities in socioeconomic conditions of humans at birth.

Aptitude↗
PubMed1977

The Southeast Asian interpretation of gender dysphoria: an illustrative case report.

In the West gender dysphoria is commonly attributed to a biological abnormality, parental influences favoring assumption of a gender opposite to the subject's anatomical sex, or a combination of these factors. In Southeast Asia (among Hindus and Buddhists), numerous cases of gender dysphoria occur. They generally receive less attention than they do in the West and evoke relatively little concern on the part of the persons affected and the members of their families. The condition is attribwted to residues of a previous life as a member of the opposite sex. Some persons with gender identity confusion claim to remember details of previous lives. A case illustrating such claims (without verifiable details) is presented.

Adjustment Disorders↗