Regeneration of defects in articular cartilage with callus and cortical bone grafts. An experimental study

Luteal-phase estrogen and progesterone concentrations were measured every other day and used to monitor the corpus luteum activity. The patterns of estrogen and progesterone concentrations were compared relative to the day of endogenous human chorionic gonadotropin (hCG) detection (defined as the day of implantation). The relationship between estrogen and progesterone and hCG concentrations was studied in 71 viable pregnancies, 12 clinical abortions, five preclinical abortions and 84 non-pregnant cycles after IVF/ET. Although all patients received luteal-phase progesterone support (25-50 mg/ml), low late luteal-phase progesterone concentrations of < 30 ng/ml from day + 11 to day + 15 were found in 64 patients (17% of viable pregnancies, 33.3% of clinical abortions, 60% of preclinical abortions and 53.6% of non-pregnant cycles) day + 1 was the day of retrieval). Implantation always occurred before or on day + 13 and 86% of pregnant cycles implanted on day + 8 to day + 11. Viable pregnancies had significantly higher mean progesterone concentrations on day + 3 to day + 7 (pre-implantation) and on day + 9 to day + 15 (postimplantation) than those of non-pregnant cycles or abortions. On the day of implantation, the mean +/- standard of deviation of estrogen (pg/ml) and progesterone (ng/ml) levels for viable pregnancies, clinical abortion and preclinical abortions were 314 +/- 210, 40.5 +/- 25; 226.7 +/- 246, 48.7 +/- 31; and 39.6 +/- 24.5, 28.6 +/- 24.5, respectively. On the same day, 73.2% of viable pregnancies, 41.7% of clinical abortions, and 20% preclinical abortions had a progesterone concentration > 30 ng/ml; 73.2% of viable pregnancies, 41.7% of clinical abortions and 20% of preclinical abortions had an estrogen concentration > 100 pg/ml. Although not precluding implantation completely, late luteal-phase hormonal deficiencies may impair endometrial growth and might ultimately lead to failure or abnormal implantation. A viable pregnancy requires not only a functional corpus luteum in the early luteal phase to develop a receptive endometrium, but also a responsive corpus luteum in the late luteal phase to support pregnancy. The time of implantation is critical. Implantation that occurs before the demise of the corpus luteum will facilitate a normal pregnancy.     

Regeneration of lesioned corticospinal tract fibers in the adult rat spinal cord under experimental conditions

The absence of fiber regrowth in the injured spinal cord and brain is influenced by several different factors and mechanisms. Among these are factors which inhibit neurite growth which are found on the surface of oligodendrocytes and central myelin. Their neutralization by a specific antibody allowed regeneration of transected corticospinal tract fibers in the adult rat spinal cord. Using a recently introduced novel neuroanatomical tracer, biotin-dextran-amine, we demonstrate the extensive regenerative sprouting of lesioned corticospinal fibers in the lesioned adult spinal cord. In the presence of the antibody against the myelin-associated neurite growth inhibitors, some of these fibers grew over remaining tissue bridges into the caudal spinal cord. They branched extensively in the lumbar spinal cord segments. These branches were decorated with synapse-like boutons. This neuroanatomical configuration probably contributes importantly to the functional recovery observed earlier in these antibody-treated animals.     

An experimental study of the effectiveness of brainstorming.

In the study of conditions favorable to creativity 2 different ways of conducting brainstorming groups were compared. 3 groups each composed of 7 university students were given instructions to uncritically invent names for 3 kinds of articles; 3 other groups of students each composed of 7 persons were given instructions to also invent names for the same articles only to do so critically. 150 different students rated the invented names of both groups for quality. "For each product, the noncritical condition produced a greater number or responses than the critical condition… . If it is the purpose of problem solving to produce a specific number of ideas of highest possible quality, these best ideas will tend to be of higher or equal quality when the noncritical method is used." From Psyc Abstracts 36:02:2HD45W. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An experimental study of the double bind hypothesis.

The primary aim of the study was to assess whether persons highly conversant with the double bind concept could reliably identify such communication in letters, and, if so, whether its presence or absence was related to the fact of the letter having been written by the parent of a schizophrenic or nonschizophrenic person. The interjudge correlations of the double bind judges were very low, indicating that their judgments regarding presence or absence of double bind communication were not reliable. Other judges achieved statistically significant interjudge reliability and were able to differentiate between letters written by parents of patients and a comparison group. It was concluded from these results that a more critical appraisal of the double bind concept is indicated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tooth mobility and resolution of experimental periodontitis. An experimental study in the dog

The aim of the present experiment was to study alterations in the mobility of teeth that occurred during resolution of experimentally induced periodontitis lesions in the dog. 5, 1-year-old, beagle dogs were used in the study. The left and right 4th, 3rd, and 2nd mandibular premolars (4P4, 3P3, 2P2) served as experimental teeth. Periodontal tissue breakdown was initiated by placing plaque-collecting cotton-floss ligatures around the neck of the experimental teeth. The ligatures were replaced to the level of the receding gingival margin 1 x every month. On Day 120, the ligatures were removed and debridement was performed. A groove, parallel to the long axis of the mesial root, was prepared in the mesio-buccal surface of the crowns of 2P and P2. Guided by the groove and with a probing force of 0.5 N, a probe was inserted into the buccal gingival pocket of the mesial root and was attached to the buccal surface. Biopsies including both the mesial and distal root of 2P and P2 and the surrounding hard and soft tissues were harvested. The biopsy procedure was repeated in a similar manner 15 days (i.e. Day 135) and 3 months (i.e. Day 225) after ligature removal in the 4th (4P4) and 3rd (3P3) premolar regions. After fixation, decalcification and sectioning, the biopsy material was exposed to histometric and morphometric measurements. Assessment of the mobility of the experimental teeth was performed on Days 120, 135 and 225 using the Periotest system.(ABSTRACT TRUNCATED AT 250 WORDS)     

Decadron in the treatment of cerebral abscess. An experimental study

Forty rabbits were inoculated with Streptococcus pyogenes or Staphylococcus aureus to produce cerebral abscesses. One-third of the rabbits received no treatment and served as controls. One-third received dexamethasone (Decadron) plus an appropriate antibiotic. One-third received only the appropriate antibiotic in the same dosage. The animals were sacrificed 10 days after inoculation and the brains examined. In the control group, an abscess at the stage of granulation tissue encapsulation containing the inoculated organisms was found. The surrounding brain showed a marked inflammatory response. In the Decadron plus antibiotic group, necrotic lesions were found containing the inoculated organisms and surrounded by relatively normal brain. In the group treated with antibiotic alone, healed glial scars were found in relatively normal brain. Our findings are discussed with reference to the medical literature regarding the influence of glucocorticoids on the inflammatory response and the efficacy of antibiotics when this response is suppressed.     

Percutaneous reinsertion of the nucleus pulposus. An experimental study

STUDY DESIGN: An analysis of the histologic changes in intervertebral discs after percutaneous reinsertion of the nucleus pulposus in rats. OBJECTIVE: To devise a way to delay further disc degeneration resulting from spinal deformity and the adverse effects of various treatments. SUMMARY OF BACKGROUND DATA: The role of the nucleus pulposus of the intervertebral disc described by many investigators has not been fully clarified. METHODS: Disc herniation was induced in the tails of 112 Wistar rats, using a fixation device between the 5th and 8th coccygeal vertebrae. After percutaneous nucleotomy at coccygeal vertebrae 5-6 and 6-7, fresh nucleus pulposus, cryopreserved nucleus pulposus, or an artificial substitute was inserted into the intervertebral disc at coccygeal vertebrae 5-6. Two, 4, or 8 weeks after reinsertion, disc sections from each coccygeal level were studied histopathologically. RESULTS: In the groups with reinsertion of fresh or cryopreserved nucleus pulposus, degenerative changes of the disc with the reinserted nucleus at coccygeal vertebrae 5-6 were milder than those of the disc without reinsertion at coccygeal vertebrae 6-7. However, no apparent benefit from reinsertion was observed in the group with artificial substitutes. CONCLUSIONS: Early reinsertion of the nucleus pulposus (fresh or cryopreserved) delays degeneration of such disc materials as the anulus fibrosus, endplate, and remaining nucleus pulposus.     

An experimental study of cross-cultural norm conflict.

"An experimental study was conducted in which normative conflict of foreign students was examined. From a treatment of norms as force-fields, predictions were made about the resolution of intergroup norm conflict under two conditions of situational potency of membership. It was hypothesized that the resolution of intergroup norm conflict favors the norm of the group whose situational potency is increased. The results obtained did not show the clarity necessary for a definitive validation of the hypotheses. The major analyses led to acceptable levels of significance in only half of the tests made; nevertheless, all the results presented a consistent pattern in harmony with the theoretical formulation." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reversibility of medialization laryngoplasty. An experimental study

Medialization laryngoplasty has become a routine procedure for cases of unilateral vocal fold paralysis. In certain clinical situations, it may become desirable to reverse the procedure and remove the implant. This process was studied experimentally in eight dogs in a chronic model of induced canine phonation. A silicone polymer implant was inserted to medialize one normal vocal fold for a period of 1 month, after which it was removed. Motion of the cricoarytenoid (CA) joint and induced phonation were studied weekly while the implant was in place, and for another month following implant removal. Significant abnormalities were found even with this relatively short period of implantation. With the implant in place, impairment of CA joint mobility was found in seven of the eight dogs, precluding phonation. A dense fibrous capsule rapidly developed around the implant, making its removal technically difficult. Following implant removal, a gradual return to normal function was found in only three of the eight dogs. One of the animals had evidence of neural injury, while four had intact neural function but impaired mobility or fixation of the CA joint. Medialization laryngoplasty should not be considered a reversible procedure. The clinical implications of these findings are discussed.     

Met-enkephalin-Arg6-Phe7 in spinal cord and brain following traumatic injury to the spinal cord: influence of p-chlorophenylalanine. An experimental study in the rat using radioimmunoassay technique

The possibility that trauma to the dorsal horn may affect the release and distribution of enkephalin was examined using the opioid peptide Met-Enk-Arg6-Phe7 (MEAP) as a marker in a rat model. The peptide content of samples of spinal cord and whole brain was measured using a radioimmunoassay (RIA) technique. In addition, the possible functional relation between this peptide and serotonin was evaluated using a pharmacological approach that included depletion of endogenous serotonin. A focal trauma to the right dorsal horn in the T10-11 segments (2 mm deep and 5 mm long) markedly modified the content of MEAP of the adjacent rostral and caudal segments of the cord, as well as the content of MEAP of the brain. Depletion of serotonin with p-CPA (an inhibitor of the synthesis of serotonin) significantly elevated the content of MEAP in the whole brain without affecting the regions of the spinal cord (except T9 level which showed a 25% decrease from an intact control group). Trauma to the spinal cord in the serotonin-depleted animals did not alter the content of MEAP further, as compared to a p-CPA-treated but untraumatized group. These results indicate that enkephalin (i) participates in the pathophysiology of spinal cord trauma and (ii) suggest that the peptide is somehow functionally related with serotonin.     

An experimental study of internalization fantasies in schizophrenic men.

Explored the types of internalization fantasies involving the constructs (or concepts or fantasies) of mother that are ameliorative in schizophrenia, using 120 18–65 yr old male schizophrenics (nonorganic). Four groups of 30 Ss received a subliminal experimental stimulus designed to activate a different fantasy of internalization as well as a subliminal neutral control message. The experimental messages were "Mommy and I are one," "Mommy and I are the same," "Mommy is inside me," and "Mommy and I are alike"; the control message was "People are walking." Assessments of pathological thinking and behavior were made before and after the presentation of each stimulus. Only the stimulus "Mommy and I are one" was effective in reducing pathology. Findings lend strong support to the contention that fantasies of oneness identification with the "good" mother are ameliorative for schizophrenics. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An experimental study of the thematic structure of primal-scene imagery.

Describes an experimental method in which the affective reactions evoked by primal-scene imagination were quantitatively assessed and systematically compared with those reactions evoked by the imagination of other scenes that usually elicit various theoretically related themes. 50 college-age persons, 25 males and 25 females, imagined a scene of their parents engaging in sexual relations, as well as other scenes emphasizing incestuous sexuality, loss and aloneness, or cognitive-confusion themes, and rated their reactions to each. Commonalities in reactions to the primal scene and the other scenes indicated that incest and aloneness themes underlie reactions to primal-scene imagery for this population. Data are consistent with observations from the clinical situation. It is expected that the scene-comparison method, which is a new research technique, will have further application for studies of unconscious processes and mental imagery. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regeneration of ascending spinal axons in goldfish

Regeneration of descending spinal cord tracts occur spontaneously in adult goldfish. Very little information is available regarding the fate of ascending fibers. Using Dextran amines as a tracer, we studied the normal and regenerated ascending axonal projection patterns in adult goldfish brain nuclei. Present study includes spinal projections to torus semicircularis, hypothalamus, thalamus and the telencephalon. Regenerated fibers had finer caliber axons and the terminal axonal arbors covered a larger area than the corresponding normal ones.     

Functional motor innervation of brachial plexus roots. An intraoperative electrophysiological study

Human T-lymphocytic virus type 1 (HTLV-1) carriage is associated with a 2% to 5% lifetime risk of developing a severe, if not fatal, disease. In our Inner London antenatal population, we found that the carrier rate was 0.3%. The antenatal transmission rate is known to be very low, but if the infant is breastfed the transmission rate is up to 25%. It is therefore possible to interrupt the transmission cycle by advising against breastfeeding. The ethical and fiscal issues surrounding antenatal testing are addressed.     

An experimental study of reinforcement and participant satisfaction.

The Es attempted to condition each S to accept a "relayer role" (see 35: 743). The relayer in a 5-man circle net collects information from the participant on one side and then passes that information plus his own to the participant on the other side. He has no opportunity to solve the problem himself. Ss were encouraged to perform the "relayer role" and were told that the group had succeeded only when they performed this role. For the questionnaire administered at the end of Trial 4, all of the satisfaction questions except task interest were interrelated in an essentially unidimensional or single-factored fashion and were significantly corelated with the number of rewards on Trials 1-4. At the end of 10 trials, however, these same items had separated into 2 independent factors. 1 factor repreesnted an evaluation of group performance and was correlated with rewards on Trials 1-10. The 2nd factor represented an evaluation of personal performance and was not related to rewards on Trials 1-10. This latter finding is not surprising in light of the fact that the Ss never did solve the problem themselves and many did not seem to understand who was solving it. The Ss with an understanding of the reward contingencies were more "satisfied" than those who did not believe their productivity was instrumental to reinforcement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Guided bone regeneration in long bone. An experimental study

To assess the satisfaction with the department and hospital services provided by a medium-size community hospital during a 2 month period (April-May 1995), 118 randomly chosen patients were asked to complete a questionnaire designed to reflect their opinions during hospitalization. The principal points of the survey concerned the general perception regarding the services in the department and the hospital, the admission and discharge procedures, the quality of food and sanitary conditions, an evaluation of the physicians' and nurses' skill and attitude, as well as their compliance to patients' needs. Overall satisfaction with the medical care was very high, the physicians' attitude and nurses' compliance being the two most important determinants. The role of this type of questionnaire as an instrument for improving health services is emphasized.     

The regenerative potential of oxytalan fibers. An experimental study in the monkey

Although a number of studies have described the oxytalan fibers as being a natural component of the periodontal ligament, little information exists about the regenerative potential of these connective tissue fibers. The aim of the present study was to examine whether oxytalan fibers have the capacity to reform after regenerative periodontal therapy. Intrabony defects were produced surgically at the mesial aspects of teeth 37, 35, 45, 47 and at the distal aspects of teeth 11, 21, 31, 41 in one monkey (Macaca fascicularis). After 3 months, the defects were exposed using a full-thickness flap procedure. The root surfaces were debrided and subsequently PDGF-growth factors were placed in the defects. 4 of the 8 sites were covered with a bioresorbable membrane before closure of the wound. Post-surgically, antibiotics were given systemically for 1 week, and tooth cleaning was carried out 1x a week during the entire experimental period. After 5 months, the animal was sacrificed and the oral tissues were fixed by perfusion with 10% buffered formalin. Specimens containing the defects and surrounding tissues were dissected free and histological sections were cut in the mesio-distal direction, parallel to the long axes of the teeth. The sections were stained with hematoxylin and eosin or with the oxone-aldehyde-fuchsin-Halmi staining method and subsequently examined in the light and in the electron microscope. The results revealed that new oxytalan fibers oriented mainly in an apico-occlusal direction had developed in the regenerated periodontal ligament. Many of the newly-formed fibers were inserted into the new cementum, thus suggesting a strong relationship between this tissue and the oxytalan fibers. It is concluded that the regenerated periodontal ligament connective tissue formed after surgery contains oxytalan fibers similar to those present in the original tissue. These results demonstrate that oxytalan fibers develop de novo in the newly-formed periodontal ligament.     

Animal intelligence: An experimental study of the associate processes in animals.

This article is an excerpt from E. L. Thorndike's (see record 2005-06679-000) "Animal intelligence: An experimental study of the associate processes in animals." The background and rationale for the study are discussed. The method chosen was to put animals when hungry in enclosures from which they could escape by some simple act, such as pulling at a loop of cord, pressing a lever, or stepping on a platform. If, after a certain time the animal did not succeed, he was taken out, but not fed. By this method of experimentation the animals are put in situations which all into activity their mental functions and permit them to be carefully observed. Advantages to using this methodology are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)