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Biomedical subjects

M Laufer

Publications and source records attributed to M Laufer.

At least 37 records · Page 2Linked to original sources
PubMed1998

Erectile dysfunction following Nd-YAG visual laser-assisted prostatectomy (VLAP).

We investigated if side fire Nd-YAG visual laser prostatectomy (VLAP) causes erectile dysfunction (ED) in patients who were sexually active prior to the procedure. The 36 study patients gave a detailed medical/sexual history: physical examination included bulbo-cavernous reflex (BCR) on rectal examination and routine blood tests. Lasing time, power of the applied laser beam (in watts), coagulation site and energy intensity were recorded. Patients with new onset ED during the one year study period underwent pudendal nerve conduction (PNC), color duplex Doppler ultrasonography, and NPT/RigiScan testing. In 6 out of 36 (16.7%) patients reporting significant post-operative ED, there was a tendency towards higher energy applied and longer lasing time but no correlation between prostate size or the site of energy application. Patients reported loss of night and/or morning erections (n = 5), retrograde ejaculations (n = 2), loss of ejaculate (n = 2), and decreased sensation of orgasm (n = 3). Three had abnormal PNC, duplex Doppler showed abnormal blood supply in four, and all six had abnormal NPT/RigiScan. We believe this is the first demonstration that VLAP may be associated with a high rate of ED and that the lasing time and intensity of applied laser energy may play a role in this outcome.

Aged↗
PubMed1997

Origins of horizontal cell spectral responses in the retina of marine teleosts (Centropomus and Mugil sp).

Intracellular recording and marking of horizontal cells (HCs) were carried out in isolated retinas of marine teleosts (Centropomus and Mugil sp.) to identify the cellular origins of different spectral types of S-potential. The spectral responses recorded under mesopic conditions were classified into four types: photopic L, biphasic C(R/G), biphasic C(G/R), and scotopic L(sL). Intracellular marking with Lucifer yellow (LY) or Procion yellow (PY) revealed that in the Centropomus retina an L-type response was recorded from H1 and H2 cells, C(R/G)-type from H3 cells, and sL-type from H4 cells. However, in 20% of microelectrode penetrations from the photoreceptor surface, the sequential order of response appearances was found to be L-, sL-, and C(R/G)-types. In this species, thick dendritic processes of H3 and H4 cells are distributed at the same level as the cell body. In the Mugil retina, on the other hand, L-type response was recorded from H1 cells, C(G/R)-type from H2 cells, C(R/G)-type from H3 cells, and sL-type from H4 cells, this sequential arrangement being very regular. In both species, the cone-connected H1 cells are small and possess an axon, while the two other cone HCs as well as rod-connected H4 cells are axonless. Earlier (Negishi et al., 1988) and present findings indicate that there is a wide variety of HC morphology and functional organization in the teleost retina.

Animals↗
PubMed1996

Effects of glutamic acid and related agents on horizontal cells in a marine teleost retina.

Excitatory amino acids (EAAs) such as glutamic and aspartic acids, considered as the most likely neurotransmitters at the photoreceptor-horizontal cell synapse of teleost retinas, as well as agonists such as kainic acid and several of their antagonists, were applied to isolated and superfused retinas of the teleost Eugerres plumieri. Intracellular recordings from horizontal cells reveal that EAA receptors are of the kainate-quisqualate type. There is competitive inhibition between the agonist and antagonist agents used, and under their combined effect, the synapse under study remains operational, in a functional state, able to modulate the horizontal cell membrane potential upon retinal illumination.

Animals↗
PubMed1996

Effect of elective prolonged urethral catheterization on serum prostate-specific antigen concentration.

OBJECTIVES: To determine the effect of an indwelling catheter on prostate-specific antigen (PSA) levels. PSA is an organ (prostate)-specific marker, and its level can be elevated in various pathologies as well as following urologic manipulations. An elevated marker may indicate the presence of prostate cancer. In the presence of an indwelling catheter, our inability to decide whether an elevated PSA value represents genuine pathology or is related to the catheter itself is often of great clinical importance. METHODS: A prospective study was conducted on 21 men with an indwelling catheter inserted electively for major nonurologic abdominal surgery to determine its influence on PSA concentration. Sera were collected before catheter insertion, 2 hours after, and then every day (average, 16 days). Catheters were left in place for an average of 5.5 days. RESULTS: Follow-up data compared to baseline and to the previous day's PSA concentrations revealed no significant change in any of the subjects. In 2 men with elevated preinsertion PSA levels (more than 10.0 ng/mL), the change over time did not differ in magnitude from changes in the other 19 men with normal pretreatment values. CONCLUSIONS: Inserting a urethral catheter and maintaining it for several days does not result in any clinically or statistically significant change in PSA levels. PSA values obtained in patients with an indwelling catheter are reliable and independent of its presence. An elevated level mandates prompt evaluation to exclude prostate cancer.

Aged↗
PubMed1996

Clinical characteristics and treatment of patients with oral lichen planus in Israel.

Oral lichen planus (OLP) has a multiple-site involvement, with the buccal mucosa being the most prevalent. A possible relationship between OLP and the risk of malignancies in the involved site is documented. The characteristics of OLP have been studied in different populations; however, no similar studies have been conducted in any Jewish population. The purpose of this study was to evaluate the natural history of OLP in Israeli Jewish patients. Data were collected from 157 charts of patients with histologically confirmed OLP. No evidence suggesting a connection between OLP and diabetes, cardiovascular disease, smoking, alcohol use, or positive Candida culture was found. Skin involvement of lichen planus was found in one fifth of the patients. Symptomatic OLP was noted in half of the patients, mainly in those with the erosive form. In 65% of the patients with symptoms, improvement by more than 50% was shown within 2 weeks of steroid use. The transformation rate of 1.3% of OLP into malignancy was observed in the entire group. A constant follow-up for contributing symptoms and for early diagnosis of suspected transformed lesions is of utmost importance.

Adrenal Cortex Hormones↗
PubMed1996

The psychoanalyst of the adolescent.

The adolescent who comes for psychoanalytic treatment has probably experienced a developmental breakdown-a rejection of his or her body and a distorted image of himself or herself as being male or female. A critical requisite for work with such adolescents is an understanding of one's own adolescent development. The internal freedom of the psychoanalyst is an essential ingredient in the treatment of the adolescent. This means that the psychoanalyst of the adolescent can separate his own sexual life and thoughts from what is lived out in the analytic sessions and thus can ensure that the treatment will confront whatever is essential and that he will avoid deriving gratification from the treatment process through taking over the adolescent's body or feeling that he is secretly sharing the intimacies of the patient.

Adolescent↗
PubMed1996

Anti-topoisomerase-I and clinical findings in systemic sclerosis (scleroderma).

The relationship between anti-topoisomerase-I antibodies and clinical findings was studied in 191 patients with definite systemic sclerosis. This was done by performing ELISA to detect antibodies to recombinant topoisomerase-I. Antibodies to topoisomerase-I were found in 72 patients (37%) with systemic sclerosis, which is a higher percentage than reported in most previous reports on a large unselected population. In 43 patients the presence of antibodies to recombinant topoisomerase-I was confirmed using both the immunodiffusion method and ELISA, with similar results. When classified into diffuse versus limited disease, a significant difference in antibody prevalence was demonstrated (P < 0.005), thus indicating that anti-topoisomerase-I antibody detection with ELISA may assist in early identification of systemic sclerosis subtypes.

Autoantibodies↗
PubMed1994

Sexual abuse, or a delusional structure? From adolescent to young adult.

The treatment of an adolescent patient who recalled having been sexually abused in childhood by her father is described. In the course of treatment, various doubts were raised in the analyst's mind about the truth of this memory. As the analysis progressed, the analyst felt that the patient's responses to interpretations were signs of the presence of a delusional structure. When the patient felt that the analyst doubted her memory, or was not on her side, she angrily and vengefully broke off her treatment. She remains a very vulnerable young woman. The delusional structure contained the patient's sexual need to destroy the male's potency as a defense against her longing for the oedipal mother who, in reality, had left the patient for a new husband.

Adolescent↗
PubMed1994

[Relevance of alfentanil as an analgesic in N20 supplemented intravenous anesthesia in ambulatory surgery].

Alfentanil is a suitable analgesic drug for nitrous oxide-supplemented intravenous anaesthesia in day case surgery--provided that the appropriate requirements are taken into consideration. Following the last bolus dose of alfentanil the plasma concentration decreased below the threshold plasma concentration for respiratory depression of 100 to 300 ng/ml alfentanil within 5 to 10 minutes. The patients showed rapid recovery from anaesthesia and were cooperative shortly after discontinuation of the intravenous drug administration. Two to three hours postoperatively there was hardly any evidence of residual impairment due to the anaesthetic. Early postoperative pain relief was required.

Adolescent↗
PubMed1993

[Modulation of electrical coupling of horizontal cells of the retina].

Horizontal cells are electrically coupled in the teleost retina. This coupling is modulated by dopamine, which is in turn liberated from interplexiform amacrine cells. The present review includes studies carried out to elucidate the intracellular mechanisms responsible for such modulation of the resistance of intercellular unions, that results from the action of dopamine on receptors located on the cell membrane. In order to study the effects of possible second messengers, hydrogen ions (H+), cyclic adenosine monophosphate (cAMP) or calcium ions (Ca2+) were injected electrophoretically from multiple microelectrodes that simultaneously allow for voltage recording in the injected cells and in neighboring ones. A resistive hexagonal network model was used to calculate the cell membrane resistance (Rm) and the coupling resistance (Ra) between the two impaled cells. Intracellular injections of Lucifer yellow were used to microscopically verify the changes produced in Ra. The microinjection of either H+ or cAMP led to reduction in coupling ratio and increase in Ra, while Rm was reduced. These changes are similar to those produced by dopamine perfusion of the retina and, equally, are corroborated by the hindrance of diffusion to neighboring cells of the Lucifer yellow injected simultaneously. No changes were detected upon Ca2+ injection, but the chelator EGTA resulted in an increased electrical coupling and Rm reduction. The results reported are consistent with the idea that both H+ and cAMP are second messengers involved in dopamine's modulation of intercellular coupling, which is produced by changes in the resistance of intercellular unions, while Ca2+ would act as a modulator through its effect on the cell membrane resistance.

Animals↗
PubMed1990

Retinal neurotransmitter interaction as reflected in horizontal cell spatial behaviour.

The effects of 5-hydroxytryptamine (5-HT) and its precursors 5-hydroxytryptophan (5-HTP) and L-tryptophan (L-Tryp) on the spatial properties of horizontal cells were studied in the isolated and perfused retina of the teleost Eugerres plumieri. All three compounds produce a contraction of the receptive field, evaluated by the ratio of responses evoked by local and distant light stimuli. This is the result of cell uncoupling, revealed by the hindrance to diffusion of intracellularly injected Lucifer yellow. Similar effects are produced by dopamine (DA) and the effectiveness is DA much greater than 5-HT greater than 5-HTP greater than L-Tryp. All these effects are blocked by Haloperidol. HPLC studies of endogenous DA release reveal that it occurs when isolated retinas are incubated with 50 mM potassium, 10 microM 5-HT or 5-HTP, but is not found with up to 1 mM L-Tryp. The results indicate that indolaminergic cells induce the release of DA from interplexiform cells, which in turn uncouples horizontal cells in the fish retina.

5-Hydroxytryptophan↗