Multicenter study evaluating target attainment of anti-Factor Xa levels using various enoxaparin prophylactic dosing practices in adult trauma patients

STUDY OBJECTIVE

Enoxaparin is standard of care for venous thromboembolism (VTE) prophylaxis in adult trauma patients, but fixed-dose protocols are suboptimal. Dosing based on body mass index (BMI) or total body weight (TBW) improves target prophylactic anti-Xa level attainment and reduces VTE rates. A novel strategy using estimated blood volume (EBV) may be more effective based on results of a single-center study. This study compared BMI-, TBW-, EBV-based, and hybrid enoxaparin dosing strategies at achieving target prophylactic anti-Factor Xa (anti-Xa) levels in trauma patients.

DESIGN

Multicenter, retrospective review.

DATA SOURCE

Electronic health records from participating institutions.

PATIENTS

Adult trauma patients who received enoxaparin twice daily for VTE prophylaxis and had at least one appropriately timed anti-Xa level (collected 3 to 6 hours after the previous dose after three consecutive doses) from January 2017 through December 2020. Patients were excluded if the hospital-specific dosing protocol was not followed or if they had thermal burns with > 20% body surface area involvement.

INTERVENTION

Dosing strategy used to determine initial prophylactic dose of enoxaparin.

MEASUREMENTS

The primary end point was percentage of patients with peak anti-Xa levels within the target prophylactic range (0.2-0.4 units/mL).

MAIN RESULTS

Nine hospitals enrolled 742 unique patients. The most common dosing strategy was based on BMI (43.0%), followed by EBV (29.0%). Patients dosed using EBV had the highest percentage of target anti-Xa levels (72.1%). Multiple logistic regression demonstrated EBV-based dosing was significantly more likely to yield anti-Xa levels at or above target compared to BMI-based dosing (adjusted odds ratio (aOR) 3.59, 95% confidence interval (CI) 2.29-5.62, p < 0.001). EBV-based dosing was also more likely than hybrid dosing to yield an anti-Xa level at or above target (aOR 2.30, 95% CI 1.33-3.98, p = 0.003). Other pairwise comparisons between dosing strategy groups were nonsignificant.

CONCLUSIONS

An EBV-based dosing strategy was associated with higher odds of achieving anti-Xa level within target range for enoxaparin VTE prophylaxis compared to BMI-based dosing and may be a preferred method for VTE prophylaxis in adult trauma patients.

GLIM criteria for the diagnosis of malnutrition - A consensus report from the global clinical nutrition community

RATIONALE

This initiative is focused on building a global consensus around core diagnostic criteria for malnutrition in adults in clinical settings.

METHODS

In January 2016, the Global Leadership Initiative on Malnutrition (GLIM) was convened by several of the major global clinical nutrition societies. GLIM appointed a core leadership committee and a supporting working group with representatives bringing additional global diversity and expertise. Empirical consensus was reached through a series of face-to-face meetings, telephone conferences, and e-mail communications.

RESULTS

A two-step approach for the malnutrition diagnosis was selected, i.e., first screening to identify "at risk" status by the use of any validated screening tool, and second, assessment for diagnosis and grading the severity of malnutrition. The malnutrition criteria for consideration were retrieved from existing approaches for screening and assessment. Potential criteria were subjected to a ballot among the GLIM core and supporting working group members. The top five ranked criteria included three phenotypic criteria (non-volitional weight loss, low body mass index, and reduced muscle mass) and two etiologic criteria (reduced food intake or assimilation, and inflammation or disease burden). To diagnose malnutrition at least one phenotypic criterion and one etiologic criterion should be present. Phenotypic metrics for grading severity as Stage 1 (moderate) and Stage 2 (severe) malnutrition are proposed. It is recommended that the etiologic criteria be used to guide intervention and anticipated outcomes. The recommended approach supports classification of malnutrition into four etiology-related diagnosis categories.

CONCLUSION

A consensus scheme for diagnosing malnutrition in adults in clinical settings on a global scale is proposed. Next steps are to secure further collaboration and endorsements from leading nutrition professional societies, to identify overlaps with syndromes like cachexia and sarcopenia, and to promote dissemination, validation studies, and feedback. The diagnostic construct should be re-considered every 3-5 years.

Long-Term Chronic Intermittent Hypobaric Hypoxia Induces Glucose Transporter (GLUT4) Translocation Through AMP-Activated Protein Kinase (AMPK) in the Soleus Muscle in Lean Rats

Background: In chronic hypoxia (CH) and short-term chronic intermittent hypoxia (CIH) exposure, glycemia and insulin levels decrease and insulin sensitivity increases, which can be explained by changes in glucose transport at skeletal muscles involving GLUT1, GLUT4, Akt, and AMPK, as well as GLUT4 translocation to cell membranes. However, during long-term CIH, there is no information regarding whether these changes occur similarly or differently than in other types of hypoxia exposure. This study evaluated the levels of AMPK and Akt and the location of GLUT4 in the soleus muscles of lean rats exposed to long-term CIH, CH, and normoxia (NX) and compared the findings.

Methods: Thirty male adult rats were randomly assigned to three groups: a NX (760 Torr) group (n = 10), a CIH group (2 days hypoxia/2 days NX; n = 10) and a CH group (n = 10). Rats were exposed to hypoxia for 30 days in a hypobaric chamber set at 428 Torr (4,600 m). Feeding (10 g daily) and fasting times were accurately controlled. Measurements included food intake (every 4 days), weight, hematocrit, hemoglobin, glycemia, serum insulin (by ELISA), and insulin sensitivity at days 0 and 30. GLUT1, GLUT4, AMPK levels and Akt activation in rat soleus muscles were determined by western blot. GLUT4 translocation was measured with confocal microscopy at day 30.

Results: (1) Weight loss and increases in hematocrit and hemoglobin were found in both hypoxic groups (p < 0.05). (2) A moderate decrease in glycemia and plasma insulin was found. (3) Insulin sensitivity was greater in the CIH group (p < 0.05). (4) There were no changes in GLUT1, GLUT4 levels or in Akt activation. (5) The level of activated AMPK was increased only in the CIH group (p < 0.05). (6) Increased GLUT4 translocation to the plasma membrane of soleus muscle cells was observed in the CIH group (p < 0.05).

Conclusion: In lean rats experiencing long-term CIH, glycemia and insulin levels decrease and insulin sensitivity increases. Interestingly, there is no increase of GLUT1 or GLUT4 levels or in Akt activation. Therefore, cellular regulation of glucose seems to primarily involve GLUT4 translocation to the cell membrane in response to hypoxia-mediated AMPK activation.

Fat mass to fat-free mass ratio reference values from NHANES III using bioelectrical impedance analysis

BACKGROUND & AIM

Low fat-free mass (FFM) or high fat mass (FM) are abnormal body composition phenotypes associated with morbidity. These conditions in combination lead to worse health outcomes, and can be identified by a high FM/FFM ratio. Here, we developed sex, age, and body mass index (BMI) stratified, population-based FM/FFM reference values using bioelectrical impedance analysis (BIA) measurements.

METHODS

White, non-Hispanic individuals aged 18-90 years old with data for weight, stature and BIA resistance measures from the third National Health and Nutrition Examination Survey (NHANES) III were included. Previously validated and sex-specific BIA prediction equations were used to calculate FM and FFM. FM/FFM values were generated at 5th, 50th and 95th percentiles for each sex, age (18-39.9, 40-59.9, 60-69.9 and 70-90 years), and BMI category (underweight, normal weight, overweight, class I/II and class III obesity).

RESULTS

A total of 6372 individuals who had estimated FM and FFM values were identified (3366 females, 3006 males). Median values of FM/FFM were 0.24 and 0.40 for young (≤39.9 years) males and females with normal BMI, and 0.34 for males and 0.59 for females who were overweight. For elderly individuals aged >70 years, median FM/FFM for males and females were respectively 0.28 and 0.45 for those with normal BMI, and 0.37 and 0.61 for those in the overweight category.

CONCLUSIONS

These FM/FFM reference values provide information on body composition characteristics that account for age, sex and BMI, which can be useful to identify individuals at risk for body composition abnormalities.

Cytochrome P450 4A11 expression in human keratinocytes: effects of ultraviolet irradiation

BACKGROUND

The skin is the major interface between the body and its environment. Directly and continuously exposed to a large variety of foreign agents and stimuli such as ultraviolet radiation (UVR), cutaneous cells are active sites of intense metabolism. The cytochromes P450 (P450) are a group of enzymes that play an important part in the protective role of the skin; they are a family of microsomal membrane-bound mono-oxygenases. These haem-containing proteins catalyse the insertion of an atom of molecular oxygen into the substrate. Although generally present at low levels, a certain number of these enzymes have now been characterized in mammalian skin as constitutive or inducible isoforms.

OBJECTIVES

To test the effects of UVR, a source of oxidative stress, on the expression of mRNA coding for several P450 isoforms (CYP), with particular reference to the CYP2E1 and CYP4A11 isoforms, which might play a role in lipid metabolism in human keratinocytes.

METHODS

Human keratinocytes were cultured, irradiated and mRNA expression was analysed by gel electrophoresis after reverse transcriptase polymerase chain reactions. CYP proteins were determined from keratinocyte microsomal fractions by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoperoxidase staining. Thin layer chromatography was used to detect (omega-1)- and (omega)-hydroxylation of lauric acid in the microsomal fractions.

RESULTS

mRNAs for CYP2E1, CYP1A1 and CYP3A5 were expressed in all the keratinocyte preparations tested; however, neither CYP3A4 nor CYP3A7 were detected, either in the presence or absence of UVR treatment. CYP19Aro, CYP2C19 and CYP26 were not expressed constitutively, although some induction of CYP19Aro was seen after combined UVB and UVA irradiation. CYP4A11 mRNA was not detected in any keratinocyte preparations either under control conditions or after UVB treatment. Nevertheless, in non-irradiated keratinocyte microsomes, two protein bands were immunoreactive with anti-CYP4A11 enzyme antibodies, one of which corresponds to CYP4A11 protein. UVA treatment of cultured keratinocytes induced CYP4A11 mRNA expression after 24 h, as well as an increase in immunoreactivity of the two protein bands. Although (omega-1)- and (omega)-hydroxylation of fatty acids is attributed to CYP2E1 and CYP4A11, respectively, in the liver or kidney, no omega-hydroxylation of lauric acid was observed in microsomal preparations from cultured keratinocytes.

CONCLUSIONS

However, CYP4A11 may participate in the defence mechanism against UVA-induced oxidative damage.

Evidence for a slow-turnover form of the Ca2+-independent phosphoenolpyruvate carboxylase kinase in the aleurone-endosperm tissue of germinating barley seeds

Phosphoenolpyruvate carboxylase (PEPC) activity was detected in aleurone-endosperm extracts of barley (Hordeum vulgare) seeds during germination, and specific anti-sorghum (Sorghum bicolor) C4 PEPC polyclonal antibodies immunodecorated constitutive 103-kD and inducible 108-kD PEPC polypeptides in western analysis. The 103- and 108-kD polypeptides were radiolabeled in situ after imbibition for up to 1.5 d in 32P-labeled inorganic phosphate. In vitro phosphorylation by a Ca2+-independent PEPC protein kinase (PK) in crude extracts enhanced the enzyme's velocity and decreased its sensitivity to L-malate at suboptimal pH and [PEP]. Isolated aleurone cell protoplasts contained both phosphorylated PEPC and a Ca2+-independent PEPC-PK that was partially purified by affinity chromatography on blue dextran-agarose. This PK activity was present in dry seeds, and PEPC phosphorylation in situ during imbibition was not affected by the cytosolic protein-synthesis inhibitor cycloheximide, by weak acids, or by various pharmacological reagents that had proven to be effective blockers of the light signal transduction chain and PEPC phosphorylation in C4 mesophyll protoplasts. These collective data support the hypothesis that this Ca2+-independent PEPC-PK was formed during maturation of barley seeds and that its presumed underlying signaling elements were no longer operative during germination.

Effects of nitric oxide donors sodium nitroprusside and 3-morpholino-sydnonimine on prolactin secretion in conscious rats

In the present study, we have examined the possible involvement of the central nitric oxide (NO) pathway in the control of prolactin secretion in vivo. The effects of intracerebroventricular (i.c.v.) injections of L-arginine (L-Arg), a precursor of NO, N omega-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthase (NOS), and of sodium nitroprusside (SNP) and 3-morpholino-sydnonimine (SIN-1), NO donors, on basal prolactin levels were studied in conscious male rats. Microinjections of L-Arg (100 and 500 mu g) or L-NAME (100 and 500 mu g) did not modify plasma prolactin levels, however i.c.v. injections of both SNP (1, 5, 10 and 20 mu g) and SIN-1 (1, 10 and 100 mu g) induced dose-dependent increases in these levels although SNP was much more potent than SIN-1. These results suggest a role of NO in the control of prolactin secretion.

Effects of ursodeoxycholic acid in patients with intrahepatic cholestasis of pregnancy

The efficacy and safety of ursodeoxycholic acid in the treatment of intrahepatic cholestasis of pregnancy was investigated in an open pilot study. Five patients received 1 gm/day of ursodeoxycholic acid during 20 days and another three patients received two identical periods of treatment separated by a 14-day interval free of the drug. Pruritus and serum levels of total bile salts and glutamic-pyruvic transaminase improved significantly during treatment with ursodeoxycholic acid. In the three patients who received two periods of treatment with ursodeoxycholic acid, pruritus and the laboratory alterations relapsed in the second week after the drug was discontinued, but they improved again when ursodeoxycholic acid was readministered. No adverse reactions were detected in the mothers or in their babies. All newborns were thriving normally during a follow-up period that lasted 5 mo after delivery. It is concluded that UDCA appears to be safe when administered in late pregnancy; its promising efficacy in the treatment of intrahepatic cholestasis of pregnancy should now be confirmed in controlled clinical trials.

S-adenosyl-L-methionine in the treatment of patients with intrahepatic cholestasis of pregnancy: a randomized, double-blind, placebo-controlled study with negative results

S-Adenosyl-L-methionine has been reported to induce beneficial effects in intrahepatic cholestasis of pregnancy. Because cholestasis of pregnancy has a high prevalence in Chile and a deleterious effect on fetal prognosis, we decided to verify the efficacy of S-adenosyl-L-methionine in this disease. Eighteen patients with pruritus that appeared during pregnancy and with elevated serum levels of bile salts (68.1 +/- 15.9 mumol/L; mean +/- S.E.M.) and ALT (226 +/- 50 KU/L) were enrolled in a prospective double-blind study comparing the effects of the drug with a placebo. S-Adenosyl-L-methionine, 900 mg, or placebo was administered in daily intravenous infusions for 20 days. Every 5 days liver function tests were done and pruritus was assessed using a preestablished score. No significant differences in pruritus or in serum levels of bile salts, ALT, bilirubin and alkaline phosphatases were seen during or after treatment between patients who received S-adenosyl-L-methionine (n = 9) or placebo (n = 9). No relevant adverse reactions were detected. Most patients had cesarean sections because of reasons unrelated to the therapeutic trial. All newborns had Apgar scores greater than 7 and normal postnatal development. Our patients had moderately severe to severe cholestasis of pregnancy as indicated by the onset of pruritus before wk 32 of pregnancy. Seven of nine multiparous patients had a past history of recurrent cholestasis of pregnancy. In this study, the administration of S-adenosyl-L-methionine during 20 days did not improve intrahepatic cholestasis of pregnancy.

Interleukin 1 alpha inhibits prostaglandin E2 release to suppress pulsatile release of luteinizing hormone but not follicle-stimulating hormone

Interleukin 1 alpha (IL-1 alpha), a powerful endogenous pyrogen released from monocytes and macrophages by bacterial endotoxin, stimulates corticotropin, prolactin, and somatotropin release and inhibits thyrotropin release by hypothalamic action. We injected recombinant human IL-1 alpha into the third cerebral ventricle, to study its effect on the pulsatile release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in conscious, freely moving, ovariectomized rats. Intraventricular injection of 0.25 pmol of IL-1 alpha caused an almost immediate reduction of plasma LH concentration; this decrease was statistically significant 20 min after injection and occurred through a highly significant reduction in the number of LH pulses, with no effect on pulse amplitude. In contrast, there was no change in pulse frequency but a small significant elevation in amplitude of FSH pulses. Intraventricular injection of the diluent had no effect on gonadotropin release. The results provide further evidence for separate hypothalamic control mechanisms for FSH and LH release. To determine the mechanism of the suppression of LH release, mediobasal hypothalamic fragments were incubated in vitro with IL-1 alpha (10 pM) and the release of LH-releasing hormone (LHRH) and prostaglandin E2 into the medium was measured by RIA in the presence or absence of norepinephrine (50 microM). IL-1 alpha reduced basal LHRH release and blocked LHRH release induced by norepinephrine. It had no effect on the basal release of prostaglandin E2; however, it completely inhibited the release of PGE2 evoked by norepinephrine. To evaluate the possibility that IL-1 alpha might also interfere with the epoxygenase pathway of arachidonic acid metabolism, epoxyeicosatrienoic acids were also measured. IL-1 alpha had no effect on the content of epoxyeicosatrienoic acids in the hypothalamic fragments as measured by gas chromatography and mass spectrometry. In conclusion, IL-1 alpha suppresses LH but not FSH release by an almost complete cessation of pulsatile release of LH in the castrated rat. The mechanism of this effect appears to be by inhibition of prostaglandin E2-mediated release of LHRH.

The crucial role of physiological Ca2+ concentrations in the production of endothelial nitric oxide and the control of vascular tone

1. The effect of varying the extracellular Ca2+ concentration on the basal and acetylcholine (ACh)-induced release of nitric oxide (NO) from the rabbit aorta was investigated by use of a superfusion bioassay system. 2. Changes between 0.5 and 2.0 mM in the concentration of Ca2+ superfusing the detector bioassay tissues or perfusing endothelium-denuded donor aortae had no effect on the tone of these tissues. 3. Increasing the concentration of Ca2+ perfusing endothelium-containing donor aortae from zero to 1.25 mM caused a transient (24 +/- 9 min), concentration-dependent basal release of NO, which was attenuated at higher concentrations of Ca2+ (1.5-2.0 mM). 4. The duration of the effect of Ca2+ on the basal release of NO was increased by a concomitant infusion of L-arginine (100 microM) through the donor aorta. 5. Changes in the concentration of Ca2+ between 0.5 and 2.0 mM had a similar biphasic effect on the release of NO induced by ACh, which was also maximal at 1.25 mM Ca2+. 6. When Ca2+ was removed from the Krebs buffer perfusing the donor aorta, the basal release of NO declined within 2 min. In contrast, the release of NO induced by ACh declined progressively over 60 min. 7. Thus changes in the concentration of Ca2+ around the physiological range modulate the synthesis of NO by the vascular endothelium and consequently, vascular tone. This may account for the effects of dietary Ca2+ supplements on the control of some hypertensive states.

Intrahepatic cholestasis of pregnancy in twin pregnancies

To clarify whether the increase in estrogen levels occurring during twin pregnancies (TP) is associated with a greater risk of developing intrahepatic cholestasis of pregnancy (ICP), we followed up 62 consecutive patients with TP and compared them with single pregnancies delivered in our hospital during 1 year. The prevalence of ICP was significantly higher in twin than in single pregnancies (20.9% versus 4.7%, respectively; P less than 0.001). Urinary estriol excretion was also significantly higher in twin compared to single pregnancies, although no quantitative differences were detected in TP with or without ICP. In multiparous patients with a proband TP affected by ICP, the disease recurred only in further TP, emphasizing the important role that estrogens seem to play in the pathogenesis of ICP. In contrast, in multiparous patients with a proband single pregnancy affected by ICP, the disease occurred in 70.5% of their other single pregnancies, suggesting the presence of a metabolic predisposition in these cases. However, in both groups of multiparous women a notable number of single pregnancies were not affected by the disease, supporting the postulate that the pathogenesis of ICP is multifactorial and that some as yet unidentified environmental factor needs to be present in order to develop the disease and also to modulate its expressivity.

Leukocytes and mediators in bronchoalveolar lavage during allergen-induced late-phase asthmatic reactions

We have measured the total and differential cell counts, histamine, leukotriene (LT) B4 and LTC4, immunoglobulins, complement (C3), eosinophil-derived basic proteins, and monocyte complement rosettes in bronchoalveolar lavage (BAL) 6 h after challenge with either antigen or diluent control in seven patients with antigen-induced single early reactions, and seven with dual (early and late phase) reactions. In both groups, the total cell counts in BAL were similar, irrespective of whether they were challenged with antigen or diluent. However, in the late-phase responders (LPR), there were significant increases in lymphocytes, neutrophils, and eosinophils (p less than 0.05), and significant decreases in the percentage of lung mast cells (p less than 0.05). The eosinophil major basic protein and eosinophil-derived neurotoxin increased in four of five subjects with dual responses and in the majority of single early responders (SER). BAL histamine concentrations increased in five of seven patients with dual responses. There were no consistent changes in LTB4 concentrations in either the LPR or the SER between diluent and antigen days, but a small but significant increase in LTC4 was observed in the LPR. Concentrations of IgG, IgA, IgM, IgE, C3, and albumin did not differ significantly. The percentage of monocyte complement rosettes also increased significantly (p less than 0.05) in LPR, but not in SER. These findings support the hypothesis that eosinophils and their products play a role in tissue injury in LPR and that eosinophil infiltration may be associated with macrophage activation.

Allergen-induced recruitment of bronchoalveolar helper (OKT4) and suppressor (OKT8) T-cells in asthma. Relative increases in OKT8 cells in single early responders compared with those in late-phase responders

We measured the numbers of helper (OKT4) and suppressor (OKT8) T-cells in blood and bronchoalveolar lavage (BAL) in 6 patients who developed single early reactions after allergen inhalational challenge and in 6 subjects who developed dual (early- and late-phase) responses. The asthmatics were lavaged twice. On the first occasion, they inhaled the diluent control (Dil) solution, and after an interval of at least 7 days, allergen (Ag) inhalational challenge was undertaken. Significant differences were observed in the single early responders (SER) only. For instance, when the results obtained on the Dil day were compared with those obtained on the Ag day, there was a significant (p less than 0.05) increase in the percentage of OKT4 cells in the blood of SER. Also in the BAL of SER there was a significant (p less than 0.05) decrease in the percentage of OKT4 and an increase (p less than 0.05) in the percentage and absolute numbers of OKT8 cells. Furthermore, the percentage of OKT4 was highly significantly (p less than 0.005) lower on the Ag day in the SER than on the Ag day in the late-phase responders (LPR). The OKT4/OKT8 ratio was significantly (p less than 0.05) lower on the Ag day than on the Dil day in BAL from SER and highly significantly decreased (p less than 0.001) when results on the Ag day in the SER were compared with those on the Ag day in the LPR. These findings raise the possibility that mobilization of suppressor T-cells into the lung after allergen-induced single early reactions in asthma might be associated with the prevention of a subsequent late-phase response.

Steatorrhea in patients with intrahepatic cholestasis of pregnancy

A prospective study was undertaken to evaluate fat malabsorption during intrahepatic cholestasis of pregnancy (ICP), a disease characterized by a mild cholestasis of short duration appearing in otherwise healthy young women. An abnormal fecal fat excretion (mean 15.8 g/24 h, range 6-31 g/24 h) was demonstrated in 10 of 12 patients with the icteric form of ICP and in 2 of 11 patients with pruritus gravidarum. The increased fecal fat excretion was generally asymptomatic, could be detected as early as 3 wk after the clinical onset of ICP, remained stable during the affected pregnancies, and returned to normal from 3 to 9 wk after delivery. Steatorrhea correlated with the severity of ICP, estimated by serum levels of bilirubin, total bile salts, and glutamic pyruvic transaminase. A significant fall in the maternal weight/height index was detected after the onset of ICP, being more intense in patients with steatorrhea than in those without it (to 92.6% +/- 3.0% of initial values versus 96.7% +/- 2.8%, respectively; p less than 0.05). A high risk of premature deliveries and fetal distress was demonstrated in these patients, also correlating with the severity of ICP. No direct relationship could be established between steatorrhea or maternal nutritional impairment and fetal prognosis.

Behavioral lateralization in the T-maze and monoaminergic brain asymmetries

Recently we have reported a marked rat lateralization in the T-maze choice. The present study examines the relationship between the ascending monoaminergic systems and the T-maze behavioral asymmetry. There were no significant differences for serotonin or norepinephrine between the T-maze preferred and non-preferred brain sides in the s. nigra, ventral tegmental area, striatum, acumbens, frontal lobe or hippocampus. Only in the hippocampus was dopamine concentration significantly greater for the brain site ipsilateral to the T-maze choice side. Previously, we reported that both apomorphine, a dopamine receptor agonist, and 6-hydroxydopamine lesion in the medial forebrain bundle of the catecholaminergic neurons affect the T-maze asymmetry; we therefore suggested that the T-maze choice could be related with the ascending dopaminergic systems. The present data strongly support this hypothesis and suggest that the DA cells involved in the spatial asymmetry in the T-maze are included in the dopaminergic mesohippocampal system.

Different roles of intrahypothalamic and nigrostriatal dopaminergic systems in thermoregulatory responses of the rat

Classically, two neurotransmitters in the brain have been implicated in thermoregulation: 5-hydroxytryptamine and norepinephrine. A dopamine action is less well-known and usually has been studied by means of pharmacological rather than physiological procedures. In the present work using a physiological approach to the problem, the role of different central dopaminergic systems in the thermoregulatory response of rats exposed to cold (4 degrees C) or warm (45 degrees C) environments has been studied. Rostral incertohypothalamic neurons in the medial preoptic area synthesized and released more dopamine in response to a warm but not to a cold environment. On the other hand DA and DOPAC levels in nigrostriatal systems were decreased by cold but not warm environments. The dopaminergic neurons projecting to nucleus accumbens or hypothalamus do not appear to be related to the thermoregulatory response in the rat.

Effects of monoamine neurotoxins injected in different brain areas on gonadotropin and androgen secretion in the male

In order to investigate the relative contribution of the serotoninergic and catecholaminergic innervation of different brain structures to the control of gonadotropin secretion in the male, adult rats were given bilateral injections of the selective neurotoxins, 5,7-dihydroxytryptamine and 6-hydroxydopamine, into the mediobasal hypothalamus, the medial preoptic area, the amygdala, and the medial forebrain bundle. Serum levels of luteinizing hormone (LH), follicle-stimulating hormone, testosterone, pituitary follicle-stimulating hormone, and LH content were measured 15 days later. The medial preoptic area 5,7-dihydroxytryptamine injections were followed by 2- to 3-fold increases of serum LH and testosterone levels and pituitary LH concentration. The 6-hydroxydopamine injections in the medial forebrain bundle resulted in a 60% decrease of pituitary LH content, associated with serum levels of LH and testosterone which were lowered, although not significantly. None of the treatments seemed to influence either serum or pituitary concentrations of follicle-stimulating hormone. These results suggest a hitherto undocumented major function of the serotoninergic innervation of the medial preoptic area in the control of LH secretion in the male and confirm previous reports indicating that some of the catecholaminergic fibers carried by the medial forebrain bundle can be modulatory for LH secretion.

Bronchoalveolar lavage in asthma: the effect of disodium cromoglycate (cromolyn) on leukocyte counts, immunoglobulins, and complement

In a double-blind, placebo-controlled study, we measured the effect of disodium cromoglycate (DSCG) on leukocyte counts, total IgE, IgG, IgA, IgM, house dust mite-specific IgE, C3, and C4 in bronchoalveolar lavage (BAL) fluid and peripheral blood in 36 atopic, perennial asthmatic subjects (DSCG 19; placebo 17). Differential cell counts on bronchial mucus were also performed. The percentage of eosinophils in bronchial mucus and BAL fluid was significantly less after DSCG. There was also a significant decrease in the concentration of total IgA (expressed as an IgA/albumin ratio) in BAL fluid after a 28-day treatment with DSCG. When the DSCG-treated patients were divided into responders and nonresponders on the basis of average daily symptom scores, the responders had significantly less bronchial mucus eosinophils, BAL eosinophils, and house dust mite-specific IgE (but not IgA) after DSCG. No significant differences in any of the measurements were observed in the nonresponders or the placebo group similarly subdivided on the basis of symptom scores. These results suggest that the efficacy of DSCG in bronchial asthma might be related to its ability to suppress the local accumulation of eosinophils and specific-IgE antibodies.

Regulation of hepatic transport of bile salt. Effect of protein synthesis inhibition on excretion of bile salts and their binding to liver surface membrane fractions

The overall transport of bile salts across the hepatocyte is characterized as a carrier-mediated process whose rate-limiting step is biliary secretion. Specific bile salt binding proteins have been identified in liver surface membrane fractions and were postulated to represent the initial interaction in bile salt translocation across both the sinusoidal and canalicular membranes. To test this hypothesis, cycloheximide was administered to rats to inhibit hepatic protein synthesis. 16 h after cycloheximide administration [14C]leucine incorporation into hepatic protein was inhibited by 93% at 1 h and 47% at 12 h. However, values of liver function tests were not increased, although serum albumin, serum alanine amino-transferase, and alkaline phosphatase were significantly decreased. Light and electron microscopy did not demonstrate necrosis or fat accumulation. The latter demonstrated minimal disorganization of rough endoplasmic reticulum and occasional lamellar whorls. 16 h after cycloheximide administration bile salt independent bile flow, basal bile salt excretion, and basal bile flow were unaltered, but the maximum bile salt transport capacity was reduced to 62% of control and 24 h later to 38%. Decreased bile salt transport was reversible, for it returned to control values after 48 h, when hepatic protein synthesis was also normal. Maximum bromosulfophthalein (BSP) transport, on the other hand, was reduced after 16 h to only 85% of control. Both bile salt and BPS maximum transport capacities decreased with time during inhibition of protein synthesis, apparently following first order kinetics. It was estimated that their half-lives are 20 h for bile salt transport and 55 h for BSP transport. These different turnover rates suggest that cycloheximide does not decrease active transport through generalized hepatic dysfunction or alteration of high energy sources possibly required for transport. The maximum number of [14C]cholic acid binding sites in liver surface membrane fractions was determined by an ultrafiltration assay. They were reduced to 68% of control after 16 h of cycloheximide and to 25% after 24 h. This reduction in the number of binding sites is apparently selective, for the activities of the liver surface membrane enzymes (Na+-K+)ATPase, Mg++-ATPase, and 5'-nucleotidase were not significantly changed. The associated alterations in bile salt transport and the maximum number of binding sites after cycloheximide administration suggests that these receptors may be the bile salt carriers.

Prevalence of intrahepatic cholestasis of pregnancy in Chile

The prevalence of intrahepatic cholestasis of pregnancy was studied immediately postpartum in 869 women from three distant Chilean cities differing in climate and food supply. Cholestatic jaundice of pregnancy was detected in 2.4% and pruritus gravidarum in 13.2%, without significant differences between the three cities. Every woman was then ethnically classified as predominantly Caucasoid, Araucanian Indian, or Aimara Indian. A significantly higher prevalence of cholestatic jaundice of pregnancy (5.5%) and pruritus gravidarum (22.1%) was found in Araucanians than in Caucasoids (2.5% and 12.6% respectively) or in the Aimaras (0 and 11.8% respectively). The prevalence of intrahepatic cholestasis of pregnancy in Araucanians increased directly with the degree of "ethnic purity." Recurrence of the disease in multiparous women was also greater in Araucanians (13.8%) than in Caucasoids (5.5%) or in the Aimaras (3.9%). We propose that an ethnic predisposition to develop intrahepatic cholestasis of pregnancy is present in Araucanian women and that the high prevalence of the disease in Chile is mainly influenced by ethnic admixture with this South American Indian (ethnic) group.