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PubMed1992

Transitions in fertility research.

History reveals that the genesis of progress in fertility research comes chiefly from animal research, and that subsequent applications of this research to humans have touched on many sensitive beliefs, prejudices, religions, and philosophies. Developments in fertility research, when applied to the human, diverge into two sensitive and very complex applied research categories-assisted reproduction and contraception. History also shows that these concurrently progressing research disciplines have undergone vacillating interludes of progress and of being blocked or restricted. Many of the technological improvements considered to be major transitional states in the progress of each of these categories are identified. They include artificial insemination, the invention of the sheath and the intrauterine device, the identification of hormones, and the elucidation of their activities as well as their interdependent relationships, the social acceptance and rejection, early embryo manipulation techniques, enzyme and sperm capacitation, and certain modern techniques involved in assisted fertility. Giant steps occurred in the 1950's with the rapid and seemingly unrestrained upward movement in chemical and clinical research that produced the hormonal contraceptives. This continued into the 1960's with additional advances providing improvements and popular choices such as intrauterine devices. In the following decades, many improvements were realized in both disciplines; however, changes in the legal environment, the litigious attitude of the public, sources of financial support, and basic priorities by industry and governments have caused uncertainty in many areas. The progressive moves seem to have occurred at certain periods when our population was not preoccupied with other matters and tended to pursue intellect and logic. This paper attempts to summarize a portion of the history of discoveries and developments in fertility research within each of the two applied research categories, and thereby to reveal and discuss a few of the underlying factors and the human qualities that impacted on the evolution of fertility research.

Journal Article↗
PubMed1991

Adolescent and older mothers' interaction patterns with their six-month-old infants.

Children of adolescent mothers suffer more physical, intellectual, and emotional difficulties than do other children. In order to gain a better understanding of the differences, the interaction patterns of adolescent mothers and non-adolescent mothers interacting with their young infants were compared. One hundred adolescent mothers and 29 married primiparous non-adolescent mothers were observed interacting with their six-month-old infants during a feeding episode and a play episode. All of the mothers had a high school education or less. During feeding, the adolescent mothers demonstrated less expressiveness, less positive attitude, less delight, less positive regard, fewer vocalizations, and a lower quality of vocalizations than non-adolescent mothers. During play, the adolescent mothers demonstrated less inventiveness, less patience, and less positive attitude than the non-adolescent mothers. These results extend and strengthen what is known about adolescent mothers patterns of interaction with their young infants.

Adolescent↗
PubMed1987

Relationship between lordosis and the position of the centre of reaction of the spinal disc.

Whenever we stand upright in apparent static equilibrium, we are, in fact, continuously making minor adjustments in order to maintain our balance. For each intervertebral joint, a point must exist at which all moments applied to the joint are continually and dynamically balanced. This point, known as the centre of reaction, is a mathematical invention necessary to perform analyses of spinal motion, but which need not be associated with any real anatomical structure. As the spine flexes and extends, this centre is expected to move; where it moves and the rationale for its motion is worthy of enquiry. In this paper, we propose that the centre of reaction remains confined to the nucleus of the disc, but only if one simple but crucial assumption is made; that the motion of the spine and control of its musculature maintain a minimum and equal stress at each intervertebral joint. This is a simple hypothesis which imposes a very specific relationship between lordosis and the centre of reaction. We investigate this relationship and its consequences on the teaching of lifting. The impossibility of designing experiments adequately to verify this hypothesis prevents in vivo verification, and, therefore, the model's verification must be made through the inferred consequences. For example, the capability of correctly predicting physiological responses of the musculoskeletal system is an indication of the validity of a model; however, this is not universally accepted. In this particular case, additional experimental data are available in the form of the locus of the centre of rotation of a vertebra vis-à-vis its lower neighbour as the spine flexes and extends. It is instructive to compare the predicted locus of the centre of reaction to experimentally determined locus of the centre of rotation; more than just coincidental similarities are found.

Biomechanical Phenomena↗
PubMed1985

Child pornography: perpetuating the sexual victimization of children.

Children have been sexually exploited throughout recorded history. The invention of the camera and subsequent related technological advances (slides, movies, instant picture cameras and videotape) have provided new avenues for the exploitation of children by facilitating the distribution of pictorial representations of these children on a world-wide basis. A major use of commercial child pornography is to convince a potential child victim that the sexual acts desired by the adult offender are fun, exciting, can satisfy the child's curiosity and are a societally acceptable means of expressing affection. Commercial child pornography publications contain numerous pictures of children viewing child pornography, in some cases replicating the pose(s) depicted in the viewed material. Although many jurisdictions have now prohibited child pornography, the need for a world-wide ban continues, as the remaining producers distribute their material throughout the world.

Child↗
PubMed1989

Separation of free and apolipoprotein D-associated human plasma lecithin: cholesterol acyltransferase.

A high performance gel filtration method for the rapid and reproducible separation of free and apolipoprotein D-associated lecithin: cholesterol acyltransferase (LCAT) originating from human plasma has been developed. Starting from step 3 of a previously invented covalent chromatography procedure, free LCAT was obtained as a well separated fraction in a yield of 55% of that injected into the column. The free LCAT had a specific activity of over 34,000 units/mg and did not contain apolipoprotein D or any other contaminant in the injected sample. Further 28% of LCAT with fully retained activity was recovered in a second fraction, demonstrating a 66,000 u LCAT associated with all apolipoprotein D occurring as a mean 33,000 u and a minor 66,000 u species and with at least two unidentified proteins with apparent molecular masses of 76,000 u and 43,000 u, respectively. Both free and apolipoprotein D-associated LCAT accepted the free cholesterol of heat-inactivated plasma selectively depleted of VLDL and LDL (alpha-LCAT activity) and of HDL (beta-LCAT activity) as substrate.

Apolipoproteins↗
PubMed1995

The brain slice preparation: a tribute to the pioneer Henry McIlwain.

Henry McIlwain is usually remembered for his major contributions to the discipline of neurochemistry. He also had a profound influence on electrophysiology by inventing and establishing the brain slice technique. This article describes some of his pioneering studies where he devised ways of preparing, both manually and mechanically (using the McIlwain tissue chopper), viable slices of mammalian cortical tissue and showed how these could be maintained in a brain slice chamber. His work with Choh-Luh Li (Li and McIlwain, 1957) on the first intracellular recording from brain slices and his work with Chosaburo Yamamoto (Yamamoto and McIlwain, 1966) describing the first study of synaptic transmission in brain slices are highlighted. In these studies, McIlwain started the use of brain slices to investigate functional anatomy, to study the effects of hypoxia and hypoglycaemia, to perform quantitative pharmacological analyses and to study synaptic plasticity: investigations which continue today to provide important insights into the functioning of the brain in health and disease.

Animals↗
PubMed1984

The Genain Quadruplets: psychological studies.

A series of behavioral studies is reported on the Genain Quadruplets. These monozygous women, all of whom have suffered or are suffering from schizophrenia, were studied previously at the National Institute of Mental Health (1955-1958) and were the subject of an extensive report by Rosenthal (1963). Although the Genains are genetically identical, the expression of the schizophrenic disorder is unequal among the quads, and this circumstance has led to speculation about the relative contributions of nature and nurture (or diathesis and stress in Rosenthal's terminology) in the development of this disease. Two goals were pursued in this investigation: one concerned a comparison of the status of the Genains in 1981 as compared with 1958; the other concerned whether data from the armamentarium of newer behavioral and neurobiological techniques invented and employed since 1958 might shed some light on the unequal expression of schizophrenia among the quadruplets. We conclude that the Genains are functioning about as well as they ever have in their adult lives, and scores on attentional tests show improvement as compared to 1958 measures. This is probably attributable to the medication (primarily neuroleptics) and other supportive treatments they have received over the years. With respect to the varying degrees of illness seen in the Genains, scrutiny of the biochemical, physiological, neuroradiological, immunogenetic, and behavioral test data leads to speculation that certain unique biochemical findings interacting with differing types and amounts of cerebral pathology constitute a major cause of the variable expression of the schizophrenic diathesis.

Antipsychotic Agents↗
PubMed1991

Efficacy of the immunoblot assay for cysticercosis in pigs and modulated expression of distinct IgM/IgG activities to Taenia solium antigens in experimental infections.

A recently invented immunoblot assay for human cysticercosis was evaluated for efficacy in pigs. The test population consists of 45 pigs with parasitologically confirmed cysticercosis, 47 with heterologous infections, 45 SPF or concrete raised control animals. With this group of 137 animals the test performance was 100% sensitive and 100% specific. The antigen-specific responses of immunoglobulin A (IgA), IgG and IgM in four pigs infected with Taenia solium eggs derived from a human were quantified by immunoblot. Antigen-specific activities were observed as early as 1 week postinfection. The first antigen-specific isotypic response was IgM antibodies directed against a glycoprotein at 97 KD (GP97). This activity generally disappeared between the sixth and ninth week postinfection. Between Weeks 5 and 8, IgG activity rose as IgM activity fell. The IgG activity, however, was directed mostly towards GP50 and GP42 antigens. If the same response occurs in people with cysticercosis, identifying specific isotype activity may help to distinguish new infection from old.

Animals↗
PubMed1986

The peritoneal cell carcinogenicity test.

The peritoneal cell carcinogenicity test, which is a new short-term in vivo-in vitro transformation test invented by Nashed (1981), was evaluated in the present report. The experimental design and materials used were as close as possible to those used by Nashed (1981). Test compounds were the two carcinogenic/non-carcinogenic analog pairs benzo[a]pyrene/pyrene and 2-acetylamidofluorene/4-acetylamidofluorene. All 4 compounds were administered orally. Al(OH)3 was injected intraperitoneally to act as mitogen for peritoneal macrophages. The criterium for transformation was colony growth of macrophages in soft agar. Two transformed cell types formed colonies under the conditions used. Pulmonary and peritoneal macrophages formed colonies when colony-stimulating factor was added. No colony growth was observed on plates with macrophages from 256 animals tested (100 carcinogen treated, 80 treated with noncarcinogenic analogs and 76 untreated controls). Thus we were not able to confirm results published previously by the inventor of this test (Nashed, 1981).

Animals↗
PubMed1990

From cornea to retinal image in invertebrate eyes.

The optical information processing that takes place in an eye involves a large variety of very different optical components that are put together to solve a task which, in its basic nature, does not differ much from one species to another. The principal task of an eye is to sort the incoming photons so that they excite specific sensory neurons depending on angle of incidence, wavelength and plane of polarization. Despite the apparent simplicity of the task, the solutions to it are often complex and the variation between species is enormous. The pinhole camera, the Keplerian and Galilean telescopes, the corner reflector, optical fibres, and interference filters, are all names of optical devices invented by man. It now appears that all of these devices, and many more, exist in various combinations in the optics of invertebrate eyes. The similarity between man's and nature's optical engineering has been useful in many ways. For the study of eyes, it has helped to understand biological design principles in unparalleled detail.

Animals↗
PubMed1992

Immunoglobulins did not arise in evolution to fight infection.

The complex interactions between B and T cells in response to external antigens are the major focus of contemporary immunology. Here, John Stewart argues that they may be relatively late evolutionary developments, due to the redeployment of a system invented for other reasons. He suggests that the system of variable region molecules (VRM) arose, at the time of the first vertebrates, by an endogenous, self-organizing process; this primordial VRM system instituted a molecular ecology, a function so important that from then on no vertebrate has been able to do without it.

Animals↗
PubMed1994

Design of protein structures: helix bundles and beyond.

The design of proteins or peptides with novel functions can be achieved either by modifying existing molecules or by inventing entirely new structures and sequences that are unknown in nature. Combinatorial-design strategies have led to the first de novo proteins, but these still lack some of the desired attributes. The most promising practical strategies for developing proteins with useful biological or chemical function combine theoretical design with experimental screening or selection systems.

Amino Acid Sequence↗
PubMed1996

Gene patents--a time to balance access and incentives.

The issue of patents on inventions of genomic research is the subject of intense debate. The exchange of scientific information and access to new technologies are critical to biomedical research. Similarly, strong patent laws are necessary to encourage innovation. Thus, it is time to balance access and incentive. Patents claiming genes with purely speculative utilities should not be issued, and they possibly limit research. Reasonable access to properly patented genes should be provided for research, and exclusive positions maintained for commercial utilities. This will promote ready access to genomic information and fundamental technologies, while optimizing the discovery and disclosure of basic advances in biomedical research.

Biotechnology↗
PubMed1994

History of medicine and changes in concept of diabetes mellitus in Japan.

In Japan, diabetes mellitus was called 'Shoukachi', thirst disease, before the 18th century. Western medicine was first introduced by the Portuguese in the 16th century. During the period of National Isolation from the 16th to the middle of the 19th century, Nagasaki served as the sole window of Japan, through which Dutch medicine came into Japan. After the Meiji Reform in the 19th century, German medicine was actively introduced. There remains a record of a lecture by Prof. Aoyama on diabetes mellitus delivered in 1906, in which the restriction of carbohydrate intake and a meat-rich diet was recommended. Prof. Sakaguchi, the successor of Prof. Aoyama and a pioneer of diabetes research in Japan, studied blood sugar profiles in healthy and diabetic subjects and invented a rice-meal test to examine glucose tolerance. In 1928, he wrote 'diabetes occurs by the deficiency of insulin, genetic factors are important, and the bodily need for insulin is increased with obesity'. He and his colleagues found that too low an intake of carbohydrate may impair glucose tolerance. After the 2nd World War, Japanese doctors eagerly learned foreign medicine, especially from the United States. Since the 1940s, a new concept has arisen in which diabetes was defined by blood glucose values after glucose loading. But, in 1970, a Committee of the Japan Diabetes Society (JDS) expressed an opinion that diabetes should not be solely defined by the results of the glucose tolerance test but should be considered as a disease or diseases with characteristic metabolic and clinical features, based on deficient insulin action.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus↗
PubMed1984

Visions for the future.

I have discussed, from my vantage point as a public health specialist, areas for emphasis in control and prevention of nosocomial infections. Surveillance is the key to all control and prevention programs. With the constraints of resources and increasing responsibilities, infection control personnel have to be innovative, inventive, and imaginative in their approach to surveillance. The principles of epidemiology may be overlooked in the rush to perform. Epidemiology is a valuable science; it is being applied to an increasing number of problems inherent to hospitals. The community and the hospital are closely related in regard to nosocomial infections. There is constant two-way traffic of both people and bugs that can be properly addressed through cooperative action. The international arena may not have a great impact on each of you, but collectively, APIC has much to offer to developing countries. We should support with actions those countries that are becoming concerned over nosocomial infections. Regardless of your own priorities, there will be new and significant challenges to all practitioners of infection control, challenges related to new and currently unidentified problems, and unfortunately, fewer resources with which to meet the challenges. I congratulate APIC, its officers, and members on all you have done to focus attention and intellect on the problem of nosocomial infections. A humble beginning has been extremely productive by all possible criteria, especially by imitation, which is "the highest form of praise."

Community-Institutional Relations↗
PubMed1991

Glass-ionomer cement--origins, development and future.

The origin of the glass-ionomer cement lies in a change in attitude regarding the qualities demanded of a dental material. The foundation of dental materials science in the 1920s tended to stultify the development of dental materials because of an over emphasis on mechanical properties. In this period, traditional materials invented before the end of the 19th century remained in use. A change in approach in the 1950s and 1960s, brought about by the realization of the importance of biocompatibility and adhesion, led to a revolution in dental materials science. This era was characterized by closer collaboration between materials research scientist and clinician. New materials were developed, including the glass-ionomer cement, with novel properties which were exploited by the development of novel clinical techniques. The glass-ionomer cement has the crucial property of adhering to untreated dentine and enamel, a quality which has led to the development of clinical techniques to minimize cavity preparation and thus loss of tooth material.

Dental Bonding↗
PubMed1994

Ethological experiments on human orientation behavior within a three-dimensional space--in microgravity.

In weightlessness situation the subject has to realize domestic and professional tasks comparable to those performed under normal gravity, whereas the "body tool" available to him has been placed in new conditions which require significant behavioral changes. The loss of weight, the disappearance or modification of some ideothetic and allothetic cues, notably the absence of gravity for the body's referential verticality have the most obvious effect of diversifying the astronaut's orientations. The vertical position is thus no longer the only one possible. This means that in order to efficiently accomplish his tasks, the subject has to invent new motor strategies which transform the quality of displacements and manipulations on the basis of the new orientation possibilities in a three-dimensional space. The previous ethological studies have dealt, in a global way, with the astronaut's motor behavior in microgravity, revealed according to an exhaustive quantitative description of the behavioral manifestions as a whole in terms of movement, posture and orientation. We now propose focusing more specifically on his spatial behavior in a three-dimensional space in microgravity. Such a situation is an exceptional experimental paradigm since at every moment, the relationships of the body referential to the surrounding space are infinitely variable: a man in space has to extract, process or use spatial information between the referentials of his moving body in all directions of the three-dimensional space and the fixed referentials of the physical environment of the space habitat. Furthermore, in the temporal dynamics, the previous ethological results showed that the behavioral events change according to the duration of the space mission, passing through different adaptative stages from a large behavioral diversity to complete behavioral reorganization. On the first day of his space mission the astronaut has however acquired experience of microgravity through his training, simulated on the ground and realized in parabolic flights. Some immediate adaptative processes are already present. As a result, the subject's experience of such a situation has to be emphasized from the initial moments of adaptation to microgravity. We thus postulate that the subject, through his orientation behavior in a three-dimensional space, according to his experience and over time, would elaborate a new representation of the space, as part of the whole adaptative process to this new environment. In order to verify such hypotheses, the present study will propose three levels of observation, i.e. three experiments in conditions of orbital flight, parabolic flight, visual simulation.

Adult↗
PubMed1989

Critical assessment of carcinogenic risk policy.

Fact. Cancer is a relatively common yet greatly feared disease. Belief. The concept that cancer is largely preventable is widely held by advocate groups, the press, and Congress. Belief. The concept that carcinogens at any level of exposure pose a significant cancer risk to human is widely believed by the public. Fact. In contrast to this belief, carcinogens are now known to be widespread in the environment and that virtually all substances are contaminated with carcinogens at some albiet low level. Fact. The solution to the ubiguitous presence of carcinogens cannot be solved by regulatory fiat. Fact. Often the only viable solution to regulating carcinogens is setting maximum levels of acceptable exposure (tolerances). Belief. In U.S. society, the process of establishing tolerances must be conducted in the open, providing adequate opportunity for public comment. Fact. The courts will sustain regulatory agency decisions about risks only if the administrative procedures used comply with the Administrative Procedures Act and if the technical methodology used is in good standing. Fact. For the method to be in good standing it cannot be a recent invention created after the fact to solve the issue at hand but must instead be a procedure that is claimed to be generally applicable to determining or estimating cancer risk. Belief. QRA should be an orderly procedure or process by which cancer risk estimations are conducted in an unbiased manner. As such it is fundamentally acceptable to the courts for resolving disputes. Fact. However, because QRA is dependent upon a large number of assumptions and because regulatory agencies feel compelled to act in a conservative, risk-adverse manner, risk estimates are often criticized for being over stated. Belief. To make risk estimates more realistic, data or facts must substitute for worst case assumptions. Fact. This process of substituting scientific facts for assumptions is occurring but it is expensive, time consuming, and not always possible. Nevertheless, it constitutes a major opportunity for improving the process by which risk estimates are made.

Animals↗