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Biomedical subjects

S Lurie

Publications and source records attributed to S Lurie.

At least 145 records · Page 8Linked to original sources
PubMed1990

The premenstrual syndrome.

PMS is probably a group of entities which include various symptoms that occur during the 7 to 10 days before menstruation and disappear a few hours after the onset of menstruation. The definition of PMS lacks objective criteria. The most common symptoms are irritability, bloating, aggressiveness, mastodynia, and headaches. The prevalence of PMS is estimated at 30 to 40 per cent. PMS is more prevalent among women working outside the home, alcoholics, women of high parity, and women with toxemic tendency; it probably runs in families. The etiology of PMS is no less obscure to us than when it was first described by Frank in 1931. No single theory has been established to explain the entire diversity of PMS symptomatology. The multitude of possible etiologic factors includes psychosocial bases, progesterone deficiency, prolactin excess, thyroid hypofunction, renin angiotensin alternations, antidiuretic hormone excess, decreased colloidosmotic pressure, endorphin activity alternations, serotonin metabolism alternations, prostaglandin action, vitamin deficiency, and such unconventional theories as the ovarian infection or the "yeast overgrowth" theory. A partial resolution of this divergence of hypotheses comes from the biopsychosocial model developed by Keye and Trunnel. According to this model, a biologic, perhaps genetically determined, predisposition to PMS is realized when past and present life experiences, attitudes, beliefs, coping styles, and social forces interact to stress a woman. The diagnosis of PMS is based on establishing a relationship between the luteal phase of the cycle and the symptoms. The evaluation of PMS patients includes the use of a monthly diary to scale the symptoms, a physical examination, and biochemical studies to rule out other disorders. Management includes education, reassurance, and drug therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

The gynaecological problems of neurofibromatosis.

The gynaecological problems of neurofibromatosis (NF) are not well documented. The present survey of the literature defines 3 main problems, namely: clitoral, vulvar and pelvic NF. The clinical suspicion of NF would in most cases improve patient care and prevent undue procedures. There remain some important unsettled questions to be answered.

Clitoris↗
PubMed1990

Age distribution of erythrocyte population in late pregnancy.

The age population distribution of erythrocytes in late pregnancy was evaluated by the volume and density distribution of cells. This approach enables an evaluation of the life span of erythrocytes in the circulation without using radioactive elements. A younger cell population was found in the circulation of women in late pregnancy as compared to nonpregnant women of similar ages, which might be indicative of shortened life span of erythrocytes. This shortened life span might be explained by the fact that erythrocytes made under conditions of increased erythropoiesis and/or increased metabolic rate show acceleration of senescence. This indication of reduced life span of the erythrocytes in late pregnancy may contribute to the understanding of the increased erythropoiesis on the one hand, and reduced hemoglobin concentration on the other hand, which often occurs in late pregnancy.

Adult↗
PubMed1989

Differential sensitivity to dexamethasone suppression in an animal model of the DST.

The present study reports the feedback suppression of basal and stimulated corticosterone secretion in rats by low doses of dexamethasone (DEX). DEX suppression of basal secretion 6 hr after administration was observed with doses as low as 0.005 mg/kg. The lowest dose capable of suppressing basal corticosterone levels for 24 hr with a return to normal values by 36 hr was established to be 0.025 mg/kg. The ability of DEX to decrease corticosterone responses to physostigmine, morphine, immobilization, and ether stress was determined. Although the magnitude of the rise in corticosterone did not differ significantly among these evocative stimuli, the degree to which DEX attenuated these responses varied. The response to morphine was completely prevented by 0.025 mg/kg and the rises following ether or immobilization were decreased significantly. In contrast, the response to physostigmine was not affected by DEX. With a higher dose of DEX (0.25 mg/kg), responses to morphine, ether, and immobilization were completely eliminated, but the response to physostigmine was only attenuated partway. The time course of the suppression in basal levels, the attenuation of several stimuli for corticosterone secretion, and the "escape" of physostigmine-induced corticosterone secretion resemble the clinical Dexamethasone Suppression Test of endogenous depression and suggest that this test might be useful in the study of animal models of depression.

Animals↗
PubMed1989

Immunopotentiation and pregnancy loss.

To test the hypothesis that immunopotentiation of the maternal immune system is beneficial for the developing embryo, we examined (1) the effect of specific preimmunization with paternal leucocytes in women and BALB/c splenocytes in CBA/J x DBA/2J mice (which show increased % fetal resorption) and (2) the influence of non-specific potentiators such as complete Freund's adjuvant and thymus humoral factor on the abortion rate in CBA/J mothers. Subsequent pregnancy was successful in 76% of habitually aborting women after immunization with paternal leucocytes. Immunization of CBA/J mice with complete Freund's adjuvant (2 foot-pad injections) decreased the resorption rate (11.3% vs 34.9% without treatment). The effect was followed by a slight decrease of the L3H4-positive lymphocyte subpopulation in the spleen but not in the draining lymph nodes, as measured by flow cytometry analysis. The amount of Lyt-2 positive lymphocytes was not changed as a result of treatment. Thymus humoral factor did not influence the abortion rate in CBA/J females mated with DBA/2J male mice. Our results show that non-specific stimulation of the maternal immune system by complete Freund's adjuvant can improve reproductive success in allogeneic mice with increased pregnancy loss. The exact mechanism of this improvement is still unclear but it seems that systemic cellular mechanisms are not responsible for the effect.

Abortion, Habitual↗
PubMed1987

Endocrine consequences of perinatal methadone exposure.

In summary, we have shown that marked acute responses as well as persistent changes in hypothalamopituitary responsivity to opiate challenge result from perinatal opioid addiction. We have also shown that different endocrine systems and opioid receptor subtypes develop at different rates, and that the responses of these systems depend upon the relative timing of the treatment regimen and the functional development of the particular opioid system involved. It should be emphasized that these studies have investigated only a single developmental window. The additional critical question of how opioid neuron function is affected by treatment during the period of active neuronal differentiation has not yet been answered. However, these studies do demonstrate the utility of this neuroendocrine model in assessing opioid function following chronic treatment regimens. By using neuroendocrine function as an end point, multiple systems can be studied simultaneously in the same animal. This has a particular advantage in studying the effects of chronic drug exposure on the developing nervous system, because hormone secretion is an easily quantifiable and early maturing functional index which can be used to identify vulnerable (and resistant) systems. Endogenous opioid systems appear to be particularly important in neuroendocrine regulation during the early phase of development, when other neural controls have not yet matured. Our preliminary results suggest that specific opioid systems that mature early may be especially important in the specific neuroendocrine effects of perinatal opiate addiction.

Aging↗
PubMed1985

Profiles of steady state levels of messenger RNAs coding for type I procollagen, elastin, and fibronectin in hamster lungs undergoing bleomycin-induced interstitial pulmonary fibrosis.

We have characterized the messenger RNAs (mRNAs) coding for procollagen alpha 1(I), elastin, fibronectin, and actin in the lungs of Syrian golden hamsters by Northern blot analyses. While elastin, fibronectin, and beta-actin were each coded for by a single mRNA species of 4.1 kilobases (kb), 9.1 kb, and 2.1 kb in size, respectively, we identified a major (5.4 kb) and a minor (6.5 kb) procollagen alpha 1(I) mRNA species in the hamster lungs. The mRNAs for the three extracellular matrix proteins showed increased accumulation followed by steady decline in the bleomycin-treated lungs. There were significant differences among the three mRNAs in the relative increase and the time of maximum accumulation. After reaching the peak levels between 2-3 wk posttreatment, the levels of procollagen alpha 1(I) and elastin mRNAs declined to near normal values around the fourth week. In contrast, the accumulation of fibronectin mRNA was maximum in the first week after bleomycin treatment. The procollagen alpha 1(I) mRNA accumulated most dramatically (sevenfold above the levels in the untreated animals) compared with a five-fold increase in mRNA coding for fibronectin. Elastin mRNA increased approximately twofold above the control values. Nuclear runoff transcription experiments demonstrated a selective increase in the rates of transcription of genes coding for procollagen alpha 1(I), fibronectin, and elastin; the extent of transcriptional stimulation of procollagen alpha 1(I) and fibronectin genes was significantly greater than that of elastin. Since the amount of actin mRNA, as well as the rate of transcription of actin gene(s), varied only slightly after bleomycin treatment, we conclude that the metabolism of mRNAs coding for extracellular matrix proteins may be preferentially perturbed during pulmonary fibrosis.

Actins↗
PubMed1983

Mode of action of plastic film in extending life of lemon and bell pepper fruits by alleviation of water stress.

The mechanism by which seal-packaging individual fruit in high density polyethylene film delays deterioration was investigated with lemon (Citrus limon [L.] Burm. f. cv Eureka) and bell pepper (Capsicum annuum L. cv Maor) fruits. Seal-packaging effects were due to the water-saturated atmosphere in the sealed enclosure around the fruit. Softening of fruit was highly correlated with declining water potential of fruit. Sealing drastically inhibited softening as well as changes in cell wall pectins. Sealing also delayed disintegration of membrane as shown by the inhibited leakage of amino acids, in particular, and electrolytes in general. All these effects of sealing were prevented or reduced by including hygroscopic CaCl(2) in the sealed enclosure which reduced the ambient humidity. Furthermore, some of these effects of sealing could be achieved also by maintaining nonsealed fruit in water-saturated atmosphere. Sealing effects could not be related to a possible ;modified atmosphere' mechanism in O(2), CO(2), or ethylene. This work supports the hypothesis that the mode of action of sealing in the polyethylene relates to the alleviation of water stress which exists in harvested fruit.

Journal Article↗
PubMed1983

Microsomal Membrane Changes during the Ripening of Apple Fruit.

The changes in leakage and viscosity of microsomal membranes from apples (Malus sylvestris cv Calville de San Sauveur) at different stages of ripening were examined. These changes were correlated with those in the lipid composition of the membranes, sterols, phospholipids, and fatty acids of the phospholipids. The greatest changes in membrane properties occurred as the fruit reached its climacteric and this corresponded with a change in the sterol:phospholipid ratio in the membranes. Changes were also found in fatty acid unsaturation level, but primarily in the postclimacteric stage of ripening.

Journal Article↗
PubMed1979

Differential Ion Stimulation of Plasmalemma Adenosine Triphosphatase from Leaf Epidermis and Mesophyll of Nicotiana rustica L.

An ATPase preparation, presumed to be associated with plasma membrane due to the coincidence on isopycnic gradients of cellulase and beta-glucan synthetase at high substrate, has been isolated from the epidermal and mesophyll of tobacco leaf. The ATPase from both tissues was found to prefer ATP over other nucleotides. The pH optimum was 7.0 in the presence of 3 millimolar MgCl(2) and pH 6.5 in the presence of 3 millimolar MgCl(2) and 100 millimolar KCl. Monovalent ion stimulation patterns of the ATPases from these tissues were found to differ and ion accumulation patterns in these tissues reflect this difference: mesophyll accumulated roughly equal amounts of Na(+) and Rb(+) and its plasma membrane ATPase is also equally stimulated by these ions; on the other hand, epidermal ATPase preparations showed a stronger stimulation by Rb(+) than Na(+) and this tissue was found to accumulate Rb(+) in preference to Na(+). Abscisic acid and fusicoccin affected both ATPase activity and ion uptake, the former inhibiting and the latter stimulating these parameters. These data support the hypothesis that the epidermal plasmalemma ATPase is involved in stomatal opening.

Journal Article↗
PubMed1977

Changing ribulose diphosphate carboxylase/oxygenase activity in ripening tomato fruit.

Tomato fruit (Lycopersicum esculentum Mill) from green, pink, and red stages were assayed for changes in the activity of ribulose diphosphate carboxylase and oxygenase, phosphoenolpyruvate carboxylase, changes in the levels of glycolate and respiratory gas exchange. The ribulose diphosphate carboxylase activity decreased as the fruit ripened. By comparison, the ribulose diphosphate oxygenase activity increased during the transition from the green to the pink stage, and declined afterward. The changes in the endogenous glycolate levels and the respiratory gas exchange, as observed at different stages of ripening, resembled the changes in the ribulose diphosphate oxygenase activity. The utilization of glycolate in further metabolic activity may result in the formation of peroxidases required for the onset of ripening.

Journal Article↗
PubMedDate not supplied

Antenatal maceration of umbilical cord; a case report.

Complete intrapartum detachment of umbilical cord at an area of maceration is described. A severely asphyxiated infant was delivered. Antenatal maceration of umbilical cord has not yet been described. The etiology of the maceration remains obscure.

Adult↗
PubMedDate not supplied

Pulse oximetry from the nasal septum.

STUDY OBJECTIVE: To evaluate the accuracy of the nasal septum site for pulse oximetry measurement of arterial oxyhemoglobin saturation (SpO2) in hypothermic patients. DESIGN: Prospective study. SETTING: Operating theater of a public hospital. PATIENTS: Fourteen hypothermic (temperature 34.6 degrees C to 36 degrees C) patients (eight males and six females) undergoing a major surgical abdominal procedure. INTERVENTIONS: Fifty estimations of SpO2 were simultaneously made by a flex sensor probe applied at the nasal septum site and by a finger sensor probe using a pulse oximeter. The results were compared with arterial oxygen saturation (SaO2) as measured by arterial blood gas sampling. MEASUREMENTS AND MAIN RESULTS: In 18% of the estimations, the finger probe produced unmeasurable results. The nasal septum probe did not produce any unmeasurable results (p = 0.0055). In the remaining 41 estimations, a comparison of the measurements from the nasal septum versus the controls showed a mean difference of 0.15 and a limit of agreement of -0.106 to +0.398. A comparison difference of 2.27 and a limit of agreement of 1.986 to 2.551. CONCLUSION: Monitoring SpO2 at the nasal septum site is more reliable than monitoring it at the finger site in hypothermic patients.

Adult↗