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Biomedical subjects

M Goldin

Publications and source records attributed to M Goldin.

At least 19 recordsLinked to original sources
PubMed2001

Functional plasticity triggers formation and pruning of dendritic spines in cultured hippocampal networks.

Despite widespread interest in dendritic spines, little is known about the mechanisms responsible for spine formation, retraction, or stabilization. We have now found that a brief exposure of cultured hippocampal neurons to a conditioning medium that favors activation of the NMDA receptor produces long-term modification of their spontaneous network activity. The conditioning protocol enhances correlated activity of neurons in the culture, in a process requiring an increase in [Ca(2+)](i) and is associated with both formation of novel dendritic spines and pruning of others. The novel spines are likely to be touched by a presynaptic terminal, labeled with FM4-64 dye, whereas the absence of such terminals increases the likelihood of spine pruning. These results indicate that long-term functional changes are correlated with morphological modifications of dendritic spines of neurons in a network.

2-Amino-5-phosphonovalerate↗
PubMed1998

Regulation of rat brain vesicular monoamine transporter by chronic treatment with ovarian hormones.

Ovarian steroids play an important role in neuroregulation and in the pathophysiology of various neuropsychiatric disorders. Most of the studies focused on the impact of gonadal steroids on post-synaptic receptors and plasma membrane transporters. In the present study, we evaluated the effect of chronic treatment with ovarian steroids on the expression of rat brain vesicular monoamine transporter (VMAT2). Ovariectomized rats were treated for 21 days with estradiol, progesterone or both. VMAT2 gene expression was assessed on the protein level by high affinity [3H]dihydrotetrabenazine ([3H]TBZOH) binding using autoradiography and on the mRNA level by in situ hybridization. Progesterone administration led to a decrease in [3H]TBZOH binding in the middle striatum and in the nucleus accumbens and to a parallel decrease in VMAT2 mRNA level in the substantia nigra pars compacta and dorsal raphè nuclei. Chronic estradiol treatment reduced VMAT2 mRNA level in the dorsal raphè and [3H]TBZOH binding in middle part of the striatum and nucleus accumbens but did not affect VMAT2 mRNA level in the substantia nigra pars compacta. Simultaneous administration of both ovarian steroids did not modulate VMAT2 mRNA in the substantia nigra pars compacta as well as [3H]TBZOH binding in the striatum or the nucleus accumbens but reduced VMAT2 mRNA level in the dorsal raphè. It appears that ovarian steroids may play a crucial role in the regulation of VMAT2 gene expression in the dopamine and serotonin systems. This modulatory activity may be relevant to synaptic and neuronal plasticity as well as to the molecular and cellular pathophysiology of gender-specific neuropsychiatric disorders.

Animals↗
PubMed1993

Atrial natriuretic peptide release in response to different positive end-expiratory pressure levels.

OBJECTIVE: To assess the influence of different positive end-expiratory pressure (PEEP) levels on plasma atrial natriuretic peptide concentrations. DESIGN: Prospective, randomized study. SETTING: Intensive care unit of a university hospital. PATIENTS: Twenty-seven patients who were mechanically ventilated due to acute respiratory failure. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The patients were randomized into three groups: in each group, a defined PEEP level (5, 10, or 15 cm H2O, respectively) was applied, alternating with zero PEEP (0 cm H2O) in consecutive order (reversal experiment). Blood samples for the determination of atrial natriuretic peptide concentrations were drawn from the pulmonary artery and the radial artery catheters. There were no decreases in atrial natriuretic peptide concentrations with a PEEP of 5 cm H2O, but significant decreases could be shown for PEEP values of 10 and 15 cm H2O. The patients of all groups were subjected to PEEP levels of 5, 10, 15, and 20 cm H2O in randomized order (step experiment). The data demonstrated a significant inverse correlation between changes in PEEP levels and changes in plasma atrial natriuretic peptide concentrations. CONCLUSION: The data suggest that the release of atrial natriuretic peptide is influenced by a PEEP of > or = 10 cm H2O, while a PEEP of < or = 5 cm H2O does not disturb this cardiac endocrine function.

Adult↗
PubMed1992

The use of fibrin sealant for embryo transfer: development and clinical studies.

Many embryo transfers after in-vitro fertilization may fail because of expulsion of the embryos from the uterus. Approximately 5-8% of pregnancies resulting from embryo transfer are ectopic. The aim of our study was to find a technique to avoid ectopic pregnancies and to improve the pregnancy rate. We used a two-component fibrin sealant which also contains a fibrinolysis inhibitor (aprotinin) at various concentrations. After gaining experience with mouse embryos, the sealant was used in human embryo transfer with great success. The results of a pilot study encouraged us to perform a prospective randomized study on 546 patients (270 with fibrin sealant, 276 conventional embryo transfers). There were 47 (17.0%) orthotopic pregnancies and 6 (2.2%) ectopic pregnancies in the control group, whereas there were 51 (18.9%) intrauterine and no ectopic pregnancies in the treatment group. The difference in ectopic pregnancies was statistically significant (P less than 0.05). With regard to the aprotinin concentration, there was a trend towards better results with 100-150 kIU (28.5% clinical pregnancies) in comparison to 250-300 kIU (19.2%) or no aprotinin (20.4%) (not significant). Further improvements of the technique may raise the pregnancy rate when fibrin sealant is used. As shown in our prospective randomized study, ectopic pregnancies may be completely avoided.

Adult↗
PubMed1989

Patient assessment of care in a pain management unit.

Seventy individuals, 40 females and 30 males with a mean age of 58.5, suffering from protracted pain and associated incapacitation (due, mainly, to rheumatoid or osteoarthrotic conditions) were treated as outpatients with the purpose of relieving their pain and improving their function. The quality of care provided was evaluated based on the outcome approach, using patient assessment of the reduction of their pain and improvement of their limitations--complemented by the assessment of the physician who treated them--and their satisfaction with the care as the measurements of their assessments. The results of the assessment indicate that on completion of treatment 23% of patients had no pain, while the pain level of the rest decreased by 64% with only three still suffering from severe pain and none from very severe pain. In the majority of patients considerable improvement of the associated functional limitation was achieved. There was a high degree of satisfaction with care received in 90% of patients.

Adult↗
PubMed1988

Short-term effect of coronary artery bypass grafting on the signal-averaged electrocardiogram.

Ventricular late potentials at the end of the QRS can be detected on the body surface during sinus rhythm by recording a signal-averaged electrocardiogram (SAECG). In patients with coronary artery disease, these late potentials have been shown to be markers for spontaneous or inducible ventricular tachycardia, or both. The short-term (before and 10 +/- 4 days after coronary revascularization) influence of coronary artery bypass grafting (CABG) on the quantitative SAECG variables was studied in 40 patients with chronic coronary artery disease. Twenty-five of these patients had a previous myocardial infarction. In the 15 patients without previous myocardial infarction, no abnormal SAECG indexes were recorded before CABG and no change in the quantitative SAECG variables was observed after surgery. In the patients with a previous myocardial infarction, 7 (28%) had a late potential before CABG. After CABG, 5 (71%) patients remained late potential-positive, whereas the other 2 (29%) lost their late potential. The mean values of their SAECG variables improved after coronary revascularization. In the entire group of postmyocardial infarction patients, the high-frequency QRS duration had shortened (p less than 0.01) after CABG (the other SAECG indexes did not change). The postoperative arrhythmic complications (transient atrial fibrillation, new onset of ventricular couplets) tended to be more frequent in the postmyocardial infarction group and in patients with late potentials. Our findings suggest that the reported increase in ventricular arrhythmias after CABG is probably not related to a change in the arrhythmogenic substrate for ventricular reentry but is associated with changes in the arrhythmogenic milieu.

Adult↗
PubMed1988

Minimal positive end-expiratory pressure (PEEP) may be "best PEEP".

In the absence of clinical trials, positive end-expired pressure (PEEP) has been accepted as efficacious for treatment of postoperative decreases in arterial oxygen tension (PaO2) from a variety of causes including adult respiratory distress syndrome (ARDS). PEEP is thought to increase PaO2 by alveolar recruitment, which in turn, has been hypothesized to play a decisive role in pulmonary recovery. One hundred and eighteen patients were followed prospectively, and after development of decreased PaO2, randomized to receive recruitive PEEP (determined by blood gas criteria) or supportive PEEP (the minimal PEEP required to maintain PaO2 above 60 mm Hg on .5 inspired O2 fraction (FIO2). No prognostic factors were significantly different between the two groups. Recruitive PEEP application in 22 patients yielded a significantly increased incidence of hypotension (55 percent), pneumothorax (20 percent), and death during treatment (27 percent) when compared to the 28 supportive PEEP patients who had no hypotension or pneumothorax and only one death during treatment (4 percent). After PEEP treatment, deaths in each group were similar (19 percent and 15 percent, respectively). We find no evidence that PEEP treatment promotes beneficial outcomes and conclude that recruitment attempts may be harmful.

Humans↗
PubMed1987

Continuous epidural infusion of morphine for pain relief after cardiac operations.

Postoperative pain relief and stress hormones were examined during the use of continuous epidural infusion of morphine at a rate of 0.1 mg/hr in 30 patients (Group B) after coronary artery bypass grafting. This was compared to our routine method of postoperative analgesia of intravenous morphine 2 mg/2 hr and as needed in another 30 patients (Group A). Continuous epidural morphine infusion required occasional supplementation with intravenous morphine and achieved effective analgesia in 80% of the patients. Pain relief was adequate in 50% of the patients in Group A. The mean dose of morphine used in Group B during the first 3 postoperative days was 5 mg per patient per day and was significantly lower than that used in Group A (mean 18 mg per patient per day). Serum morphine was undetectable (below 2.5 ng/ml) in Group B and was significantly lower than that in Group A (17 ng/ml). Epidural analgesia was associated with adequate postoperative pulmonary and cardiovascular functions; nausea and vomiting occurred in two patients. Levels of postoperative stress, serum cortisol, and beta-endorphin were significantly lower in Group B than in Group A. This study shows that continuous epidural infusion of morphine at a rate of 0.1 mg/hr provides selective and effective pain relief and reduces postoperative stress after cardiac operations. This method of analgesia was also associated with minimal side effects and provides an alternate approach for treatment of pain after cardiac operations.

Adult↗
PubMed1987

Penetration of bacteria and spermatozoa into bovine cervical mucus.

It has been reported that bacteria may attach to motile spermatozoa, be carried through the cervix and uterus to the fallopian tubes, and cause acute salpingitis. In an attempt to mimic these conditions in vitro, we incubated Escherichia coli, Streptococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus with motile spermatozoa which then were allowed to migrate through a capillary filled with bovine cervical mucus. After satisfactory sperm migration through the mucus, the capillaries were broken and cultured at different distances from the original insemination site. Mucus fractions in proximity to bacterial inocula grew varying amounts of the pathogens. More distal fractions of mucus columns were generally culture-negative even though they contained motile sperm which had been exposed to bacteria. Migration of spermatozoa exposed to bacteria through bovine cervical mucus did not result in enhanced bacterial penetration.

Animals↗
PubMed1984

Staphylococcal abscess complicating endocardial aneurysmectomy.

Subendocardial left ventricular aneurysmectomy relieved previously intractable ventricular tachycardia in a 68-year-old man with severe coronary artery disease. Staphylococcal septicemia developed postoperatively; an infected venoclysis site may have provided the portal of entry. Autopsy confirmed staphylococcal abscess at the epicardial aspect of the ventriculotomy, constituting the first reported case, to our knowledge, of this complication following endocardial surgery.

Abscess↗