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Biomedical subjects

D Kleinman

Publications and source records attributed to D Kleinman.

48 records · Page 3Linked to original sources
PubMed1975

"Stimulus generalization" between differentiated visual, auditory, and central stimuli.

Cats were trained to discriminate between two different repetition rates of flicker and of click. Both approach-approach and avoidance-avoidance discriminations were used. After substantial overtraining, transfer of frequency discrimination was initiated to stimulation of the reticular formation using bursts of electrical pulses at the same two repetition rates. Significant levels of discriminated performance were obtained in all cats very quickly, indicating good cross-modal transfer between the peripheral discriminanda and the central stimuli. The literature on stimulus generalization and cross-modal transfer is reviewed and the findings of this experiment are discussed in that context. Certain conditions are defined which, if satisfied, justify the interpretation that stimulus generalization or rapid cross-modal transfer indicate that facilitation of subsequent tasks in a training sequence can be attributed to mediation by a specific neuronal mechanism established by training on a previous task. The present experiment was designed in view of such criteria. The evidence of good cross-modal transfer is interpreted to mean that brain mechanisms storing memories about discriminations between visual or auditory stimuli with different repetition rates can be effectively activated by gross electrical stimuli at the same repetition rates. Conflict trials were then carried out in which flicker or click at either frequency was contradicted by concurrent RF stimuli at the other frequency. As the current level of RF stimuli was parametrically increased, it was found that the central stimuli achieved almost complete control over the behavioral outcome in most cases. Concurrent transfer of training, using a counterbalanced training sequence, was then carried out to stimulation of the visual cortex, lateral geniculate, medial geniculate, and the intralaminar nuclei of the thalamus. In each case, rapid transfer was displayed by at least one animal. Once performance to brain stimulation at a given repition rate was established, little change was observed when the fine structure of the stimulus was altered by changing parameters of the stimulus burst. These findings are interpreted as providing support for a statistical theory of memory, since they constitute evidence that previously learned discriminative behavior can readily be elicited by compelling large ensembles of neurons in various brain regions to discharge with particular temporal patterns. It is difficult to reconcile these results with theories which postulate that learning establishes new synaptic pathways in which discharge must occur for memories to be retrieved.

Animals↗
PubMedDate not supplied

Combined anesthetic and surgical treatment of reflex sympathetic dystrophy following a healed crush injury of the foot.

Reflex sympathetic dystrophy is an often overlooked diagnostic cause of posttraumatic pain. After wound healing, persistent pain frequently is treated with continued analgesic administration, physical therapy, acupuncture, nerve blocks, psychotherapy and sometimes even ignored in hopes that either the pain or the patient will "go away." The authors relate successful evaluation and treatment of reflex sympathetic dystrophy in the case of a young man with disabling pain following a healed crush injury to his foot.

Adult↗
PubMedDate not supplied

Specific IgG and IgA antibodies to Chlamydia trachomatis in infertile women.

IgG, IgA, and IgM antibody titers to Chlamydia trachomatis were determined in sera of 80 infertile women and 100 controls by a single antigen (L-2) immunoperoxidase assay. The infertile women included 50 with unexplained infertility and normal hysterosalpingogram (HSG) and 30 with abnormal HSG. The control sera included 50 from primiparous and 50 from multiparous women. The prevalence of C. trachomatis IgG antibody was significantly higher in infertile women with abnormal HSG as compared with infertile patients with normal HSG and controls (87% v. 20% and 10%, respectively). The geometric mean titer (GMT) of C. trachomatis IgG antibodies of infertile women with abnormal HSG was significantly higher than those of controls (20.7 v. 5.6). A significantly higher prevalence of C. trachomatis IgA antibodies was found in infertile women with both abnormal and normal HSG than in controls (77% and 14% v. 3% respectively). No C. trachomatis IgM antibodies (less than 2) were found in any of the infertile or control groups. The possibility that serum C. trachomatis IgA antibodies may serve as a marker for early recognition of persistent C. trachomatis is discussed.

Adult↗
PubMedDate not supplied

Immunoperoxidase assay for detection of specific IgG and IgA antibodies to human spermatozoa in infertile women.

A new immunoperoxidase antibody-membrane antigen (IPAMA) technique for the detection of IgG and IgA antibodies specific for sperm antigens is described. The technique utilizes as antigen sperm cells dried on glass slides and stored at -70 degrees C. Sera of 82 infertile women, 50 primiparas, 50 multiparas and 25 children were tested by IPAMA. Results obtained with the IPAMA test for sperm-specific IgG are compared with the results obtained by the sperm immobilization test (SIT). By the IPAMA technique, 11 of 82 infertile women (13.4%) were positive for sperm-specific IgG antibodies, 12 (14.6%) for IgA antibodies and three (3.7%) for both. In the control groups only two of 125 subjects were positive for sperm-specific IgG and none for IgA antibodies. The difference in the prevalence of anti-sperm antibodies between the control groups and the infertility group was highly significant (P less than 0.001). There was agreement between the results of the IPAMA and SIT as to the presence or absence of antibodies in seven of the 11 IgG-positive sera in the infertility group. Four more sera were IgG positive by IPAMA only. The two positive sera in the control group were detected by both IPAMA and SIT. Since the IPAMA technique is simple, does not require special equipment and utilizes stored antigen, it seems that this method could be useful in mass screening of infertile couples.

Adult↗
PubMedDate not supplied

Perinatal outcomes in women with systemic lupus erythematosus.

OBJECTIVE: Pregnancies of women with systemic lupus erythematosus (SLE) were studied to assess the effects interaction of this disease and pregnancy. STUDY DESIGN: Charts of pregnant women with a discharge diagnosis of lupus were reviewed. Inclusion criterion was SLE diagnosed by the criteria of the American College of Rheumatology. All patients were cared for at the University of North Carolina Hospitals, a tertiary level university center. RESULTS: Between January 1988 and June 1995, we participated in the care of 21 women with the diagnosis of SLE. Their obstetric histories included a total of 56 pregnancies spanning 19 years. Obstetric histories were divided into pregnancies occurring before the patient was diagnosed with lupus and those pregnancies occurring after she had been given the diagnosis. The diagnosis of lupus was made during the course of five pregnancies; those five were categorized as occurring after diagnosis. Of the pregnancies that occurred before a woman's diagnosis of SLE, 46% resulted in live births, 36% ended in spontaneous abortion, and 18% ended in an intrauterine fetal demise. Among pregnancies occurring after the diagnosis of SLE, 85% resulted in live birth, 10% in spontaneous abortion, 3.3% in intrauterine fetal demise, and 3.3% in neonatal death. Of all live births, 53% were delivered before 37 weeks' gestation. The most common causes of maternal morbidity were joint involvement (n = 8) and dermatologic disorders (n = 6). Other clinical manifestations of SLE included nephritis (n = 5), hypertension (n = 4), pleuritis (n = 3), and thrombocytopenia (n = 3). One maternal death occurred as a result of pulmonary disease. Four pregnancies were complicated by preeclampsia. Seven patients were hospitalized during their pregnancies for lupus-related complications. CONCLUSIONS: Substantial fetal, neonatal, and maternal risks still exist for pregnant women with lupus.

Birth Rate↗