Cost saving in implementing ERAS protocol in emergency abdominal surgery

INTRODUCTION

ERAS (Enhanced Recovery After Surgery) protocol is now proposed as the standard of care in elective major abdominal surgery. Implementation of the ERAS protocol in emergency setting has been proposed but his economic impact has not been investigated. Aim of this study was to evaluate the cost saving of implementing ERAS in abdominal emergency surgery in a single institution.

METHODS

A group of 80 consecutive patients treated by ERAS protocol for gastrointestinal emergency surgery in 2021 was compared with an analogue group of 75 consecutive patients treated by the same surgery the year before implementation of ERAS protocol. Adhesion to postoperative items, length of stay, morbidity and mortality were recorded. Cost saving analysis was performed.

RESULTS

50% Adhesion to postoperative items was reached on day 2 in the ERAS group in mean. Laparoscopic approach was 40 vs 12% in ERAS and control group respectively (p ,002). Length of stay was shorter in ERAS group by 3 days (9 vs 12 days p ,002). Morbidity and mortality rate were similar in both groups. The ERAS group had a mean cost saving of 1022,78 € per patient.

CONCLUSIONS

ERAS protocol implementation in the abdominal emergency setting is cost effective resulting in a significant shorter length of stay and cost saving per patient.

OP0290 EMAPALUMAB (ANTI-INTERFERON-GAMMA MONOCLONAL ANTIBODY) IN PATIENTS WITH MACROPHAGE ACTIVATION SYNDROME (MAS) COMPLICATING SYSTEMIC JUVENILE IDIOPATHIC ARTHRITIS (SJIA)

Background:

MAS is a severe complication of rheumatic diseases and occurs most frequently in patients with sJIA. Data from animal models and from observational studies in patients suggest that interferon gamma (IFNy) is a driver of the hyperinflammation and hypercytokinemia observed in MAS.

Objectives:

To assess the pharmacokinetics, efficacy, and safety of intravenous (IV) infusions of emapalumab, a fully human anti-IFNγ monoclonal antibody, in patients with MAS in the context of sJIA.

Methods:

This ongoing, pilot, open-label, single-arm study (NCT03311854) includes patients with MAS (2016 ACR/EULAR criteria) on a background of confirmed, or high presumption of, sJIA, and with inadequate response to high-dose IV glucocorticoids. Emapalumab is initiated at 6 mg/kg (1 dose) and continued at 3 mg/kg twice weekly for a total of 4 weeks, or less upon achievement of complete response (CR). CR is defined as an absence of MAS clinical signs plus white blood cell and platelet counts above the lower limit of normal, LDH, AST and ALT <1.5 x upper limit of normal, fibrinogen >100 mg/dL, and ferritin decreased by ≥80% or to <2,000 ng/mL.

Results:

We report preliminary data from the first 9 patients (median age [range] 11.6 [2.1-25.3] years) enrolled (7 in Europe and 2 in the USA). All patients had failed high-dose methylprednisolone, of which there were prior treatment failures from cyclosporin A (n=4) and from anakinra (n=4). Treatment with emapalumab resulted in rapid IFNγ neutralization, as demonstrated by the decrease in CXCL9 levels (Figure 1), and subsequent deactivation of T cells, as indicated by the decrease in sIL-2R levels. CR was achieved in all patients after a median of 23 (12-56) days. A progressive improvement in all clinical and laboratory parameters of MAS was observed (Table 1 and Figure 2). Glucocorticoids were tapered in all patients (median % tapering -92%; range -45% to -98% at Week 8). Emapalumab infusions were well tolerated by all patients, with no discontinuation. CMV reactivation was reported in 1 patient as a serious event possibly related to emapalumab and resolved with antiviral treatment.

Table 1.

Time to response for key clinical and laboratory parameters.

ParametersMedian baseline value (range)Median days of treatment (range)D-dimers to <1000 mg/L12,480 (550-89,552)15 (1-49)sIL-2R to <2000 ng/L4596 (1664-20,954)21 (6-37)Ferritin <500 mg/L29,240 (716-192,584)21 (9-42)Physician visual analog scale of MAS activity ≤19.0 (2-10)19 (9-56)All MAS laboratory parameters within range of CRNA21 (15-55)All MAS parameters within range of CRNA23 (12-56)Glucocorticoid tapering at ≤1 mg/kg prednisolone equivalent*NA42 (16-50)

*Data incomplete for 1 patient

Figure 1.

Rapid neutralization of IFNy. Each line represents an individual patient (n=9).

Figure 2.

Ferritin levels and platelet counts over time.

Conclusion:

Emapalumab administration led to rapid neutralization of IFNy and was efficacious in controlling MAS with a favorable safety profile. These results support the pathogenic role of IFNγ in MAS/sJIA and the therapeutic value of IFNγ neutralization in MAS patients who have failed standard of care.

Disclosure of Interests:

Fabrizio De Benedetti Grant/research support from: AbbVie, Pfizer, Novartis, Novimmune, Sobi, Sanofi, Roche, Speakers bureau: AbbVie, Novartis, Roche, Sobi, Paul Brogan Grant/research support from: Sobi, Novartis, Roche, Chemocentryx, Consultant of: Roche, Sobi, Speakers bureau: Sobi, Roche, Novartis, UCB, Claudia Bracaglia: None declared, Manuela Pardeo: None declared, Giulia Marucci: None declared, Emanuela Sacco: None declared, Despina Eleftheriou Speakers bureau: Sobi, Charalampia Papadopoulou: None declared, Alexei Grom Grant/research support from: Novartis, AB2Bio, Consultant of: Novartis, Pierre Quartier Consultant of: AbbVie, Chugai-Roche, Lilly, Novartis, Sanofi, Sobi, Speakers bureau: AbbVie, BMS, Chugai-Roche, Novartis, Pfizer, Sobi, Rayfel Schneider Grant/research support from: Roche, Novartis, Sobi, Pfizer, Consultant of: Sobi, Novartis, Novimmune, Philippe Jacqmin Consultant of: Sobi, Rikke Frederiksen Employee of: Sobi, Maria Ballabio Employee of: Sobi, Cristina De Min Employee of: Sobi

Unusual oral presentation of HSV-1 lesions in an adult liver transplant recipient

Herpes Simplex Virus (HSV) hepatitis in liver transplant patients is a rarely reported infective complication of HSV with severe consequences, often leading to fulminant hepatitis if left untreated. The clinical signs are often atypical, leading to under-reporting in the literature and potential delays in treatment. Our case report describes such atypical mucocutaneous lesions in a liver transplant recipient. We highlight the need for further reports, especially those with images, in order to aid the diagnosis of HSV infection, and to allow prompt treatment to prevent complications such as HSV hepatitis.

Quasi-thresholdless Photon Upconversion in Metal-Organic Framework Nanocrystals

Photon upconversion based on sensitized triplet-triplet annihilation ( sTTA) is considered as a promising strategy for the development of light-managing materials aimed to enhance the performance of solar devices by recovering unused low-energy photons. Here, we demonstrate that, thanks to the fast diffusion of excitons, the creation of triplet pairs in metal-organic framework nanocrystals ( nMOFs) with size smaller than the exciton diffusion length implies a 100% TTA yield regardless of the illumination condition. This makes each nMOF a thresholdless, single-unit annihilator. We develop a kinetic model for describing the upconversion dynamics in a nanocrystals ensemble, which allows us to define the threshold excitation intensity  I_th^box required to reach the maximum conversion yield. For materials based on thresholdless annihilators, I_th^box is determined by the statistical distribution of the excitation energy among nanocrystals. The model is validated by fabricating a nanocomposite material based on nMOFs, which shows efficient upconversion under a few percent of solar irradiance, matching the requirements of real life solar technologies. The statistical analysis reproduces the experimental findings, and represents a general tool for predicting the optimal compromise between dimensions and concentration of nMOFs with a given crystalline structure that minimizes the irradiance at which the system starts to fully operate.

Highly Fluorescent Metal-Organic-Framework Nanocomposites for Photonic Applications

Metal-organic frameworks (MOFs) are porous hybrid materials built up from organic ligands coordinated to metal ions or clusters by means of self-assembly strategies. The peculiarity of these materials is the possibility, according to specific synthetic routes, to manipulate both the composition and ligands arrangement in order to control their optical and energy-transport properties. Therefore, optimized MOFs nanocrystals (nano-MOFs) can potentially represent the next generation of luminescent materials with features similar to those of their inorganic predecessors, that is, the colloidal semiconductor quantum dots. The luminescence of fluorescent nano-MOFs is generated through the radiative recombination of ligand molecular excitons. The uniqueness of these nanocrystals is the possibility to pack the ligand chromophores close enough to allow a fast exciton diffusion but sufficiently far from each other preventing the aggregation-induced effects of the organic crystals. In particular, the formation of strongly coupled dimers or excimers is avoided, thus preserving the optical features of the isolated molecule. However, nano-MOFs have a very small fluorescence quantum yield (QY). In order to overcome this limitation and achieve highly emitting systems, we analyzed the fluorescence process in blue emitting nano-MOFs and modeled the diffusion and quenching mechanism of photogenerated singlet excitons. Our results demonstrate that the excitons quenching in nano-MOFs is mainly due to the presence of surface-located, nonradiative recombination centers. In analogy with their inorganic counterparts, we found that the passivation of the nano-MOF surfaces is a straightforward method to enhance the emission efficiency. By embedding the nanocrystals in an inert polymeric host, we observed a +200% increment of the fluorescence QY, thus recovering the emission properties of the isolated ligand in solution.

Tumor suppressor Nf2/merlin drives Schwann cell changes following electromagnetic field exposure through Hippo-dependent mechanisms

Previous evidence showed mutations of the neurofibromin type 2 gene (Nf2), encoding the tumor suppressor protein merlin, in sporadic and vestibular schwannomas affecting Schwann cells (SCs). Accordingly, efforts have been addressed to identify possible factors, even environmental, that may regulate neurofibromas growth. In this context, we investigated the exposure of SC to an electromagnetic field (EMF), which is an environmental issue modulating biological processes. Here, we show that SC exposed to 50 Hz EMFs changes their morphology, proliferation, migration and myelinating capability. In these cells, merlin is downregulated, leading to activation of two intracellular signaling pathways, ERK/AKT and Hippo. Interestingly, SC changes their phenotype toward a proliferative/migrating state, which in principle may be pathologically relevant for schwannoma development.

Effect of postnatal starvation on the 5 alpha-reductase activity of the brain and of the isolated myelin membranes

The 5 alpha-reductase, the enzyme which converts testosterone into its major "active" metabolite (dihydrotestosterone, DHT), has been found to be present in high concentration in brain structures particularly rich of myelin (white matter structures), as well as in myelin membranes. Previous ontogenetic observations seem to indicate that, during the process of myelinogenesis, the enzyme might be synthesized in the oligodendrocytes, and subsequently incorporated into the myelin membranes. It is well established that postnatal malnutrition produces a decreased formation of myelin, when starvation is performed from birth until to the 2nd or 3rd week of life; on the contrary food deprivation does not produce any significant effect on myelin accumulation when performed after the 14th day of life. The present experiments have been performed in the rat in order to study the effects of postnatal undernutrition (from birth to the 19th day of life: long malnutrition; and from the 14th to the 19th day of life: short malnutrition) on the 5 alpha-reductase activity present in the following brain structures: cerebral cortex, hypothalamus, corpus callosum, pyramidal tract, as well as in isolated myelin membranes. Undernourished animals have been killed at 20 days of age. Normally nourished animals served as controls. Long undernutrition induced a statistically significant decrease of the formation of DHT in the corpus callosum and in the pyramidal tract vs controls. On the contrary, the nutritional deficiency did not decrease the 5 alpha-reductase activity in the cerebral cortex and in the hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroactive steroids influence peripheral myelination: a promising opportunity for preventing or treating age-dependent dysfunctions of peripheral nerves

The process of aging deeply influences morphological and functional parameters of peripheral nerves. The observations summarized here indicate that the deterioration of myelin occurring in the peripheral nerves during aging may be explained by the fall of the levels of the major peripheral myelin proteins [e.g., glycoprotein Po (Po) and peripheral myelin protein 22 (PMP22)]. Neuroactive steroids, such as progesterone (PROG), dihydroprogesterone (5alpha-DH PROG), and tetrahydroprogesterone (3alpha,5alpha-TH PROG), are able to stimulate the low expression of these two myelin proteins present in the sciatic nerve of aged male rats. Since Po and PMP22 play an important physiological role in the maintenance of the multilamellar structure of PNS myelin, we have evaluated the effect of PROG and its neuroactive derivatives, 5alpha-DH PROG and 3alpha,5alpha-TH PROG, on the morphological alterations of myelinated fibers in the sciatic nerve of 22-24-month-old male rats. Data obtained clearly indicate that neuroactive steroids are able to reduce aging-associated morphological abnormalities of myelin and aging-associated myelin fiber loss in the sciatic nerve.

Effects of neuroactive steroids on myelin of peripheral nervous system

Peripheral nervous system (PNS) possess both classical (e.g. progesterone receptor, PR, androgen receptor, AR) and non-classical (e.g. GABA(A) receptor) steroid receptors and consequently may represent a target for the action of neuroactive steroids. Our data have indicated that neuroactive steroids, like for instance, progesterone, dihydroprogesterone, tetrahydroprogesterone, dihydrotestosterone and 3alpha-diol, stimulate both in vivo and in vitro (Schwann cell cultures), the expression of two important proteins of the myelin of peripheral nerves, the glycoprotein Po (Po) and the peripheral myelin protein 22 (PMP22). It is important to highlight that the mechanisms by which neuroactive steroids exert their effects on the expression of Po and PMP22 involve different kind of receptors depending on the steroid and on the myelin protein considered. In particular, at least in culture of Schwann cells, the expression of Po seems to be under the control of PR, while that of PMP22 needs the GABA(A) receptor. Because Po and PMP22 play an important physiological role for the maintenance of the multilamellar structure of the myelin of the PNS, the present observations might suggest the utilization of neuroactive steroids as new therapeutically approaches for the rebuilding of the peripheral myelin.

Evaluation of lanreotide effects on human exocrine pancreatic secretion after a single dose: preliminary study

BACKGROUND

Total parenteral nutrition and somatostatin or analogues represent a consolidated therapeutic approach for external fistulas, a frequent complication of major pancreatic surgery.

AIMS

To establish the effects of the somatostatin analogue lanreotide on exocrine pancreatic secretion.

METHODS

Eight patients, undergoing pancreaticoduodenectomy for malignancy, were enrolled in the trial. The volume and composition of pancreatic secretion were evaluated after one single subcutaneous injection of lanreotide 0.5 mg or placebo in a randomised, double-blind cross-over trial.

RESULTS

In the seven patients completing the study, the 24-h output volume was 208.6+/-41.3 and 253.9+/-72.4 ml after lanreotide and placebo, respectively. During the first 6 hours values were 48.1+/-14.7 and 77.6+/-21.4 ml (p=0. 02). No significant difference between treatments was detected in the qualitative composition of 24-h pancreatic secretion, although bicarbonate secretion remained lower after the active drug at all the observation intervals. Peak lanreotide levels were detected 15-30 min after drug injection. Clinical and laboratory tolerability was good.

CONCLUSIONS

Lanreotide induced a statistically significant reduction in the output volume with respect to placebo in the first 6 hours after administration, but not thereafter. The present results encourage a new study to be undertaken in a larger sample and with a multiple dosing scheme of treatment.

A double-blinded evaluation of propacetamol versus ketorolac in combination with patient-controlled analgesia morphine: analgesic efficacy and tolerability after gynecologic surgery

We assessed the relative morphine consumption in a combined analgesic regimen (on-demand morphine plus the nonopioids propacetamol or ketorolac) after gynecologic surgery. Two hundred women randomly received two i.v. doses of propacetamol 2 g or ketorolac 30 mg in a double-blinded, double-dummy trial. Patients were monitored for 12 h, and the following efficacy variables were assessed: total dose of morphine, pain intensity, and global efficacy. Safety and tolerability were evaluated by the occurrence of adverse events, especially the presence and intensity of gastrointestinal symptoms. Hemostatic variables were measured 30 and 60 min after the first infusion; arterial blood pressure, heart and respiratory rates, sedation scores, and renal and hepatic function were also assessed. Total morphine requirements were not significantly different between the propacetamol (10.6 +/- 4.8 mg) and ketorolac (10.2 +/- 4.4 mg) groups. The evolution of pain intensity and the global efficacy also showed similar patterns in the two groups: 70.2% of patients in the propacetamol group rated the efficacy as "good/ excellent" compared with 68.2% in the ketorolac group. There were no clinically significant changes in vital signs or laboratory values and no observed differences between the two groups, although ketorolac slightly, but not significantly, prolonged the bleeding time. Epigastric pain was present in 9% and 15% of patients receiving propacetamol and ketorolac, respectively. There were two adverse events in the propacetamol group and four in the ketorolac group. Propacetamol demonstrates an efficacy similar to that of ketorolac and has an excellent tolerability after gynecologic surgery.

IMPLICATIONS

Propacetamol and ketorolac, combined with patient-controlled analgesia morphine, show similar analgesic efficacy after gynecologic surgery. Morphine consumption and pain scores were comparable in the two studied groups. Propacetamol is as effective as ketorolac and has an excellent tolerability after gynecologic surgery.

Efficacy of propacetamol in the treatment of postoperative pain. Morphine-sparing effect in orthopedic surgery. Italian Collaborative Group on Propacetamol

BACKGROUND

Combined analgesic regimens have been suggested to improve the treatment of postoperative pain. The aim of our study was to evaluate the analgesic efficacy and tolerability of propacetamol, in combination with morphine.

METHODS

Four i.v. infusions of propacetamol 2 g or placebo were administered, in a double-blind fashion, after orthopedic surgery (n = 97). Morphine was administered by a patient-controlled analgesia (PCA) device. The total dose of morphine, pain intensity and global efficacy of treatment were evaluated. Tolerability was assessed by monitoring blood pressure, heart and respiratory rate, sedation scores, adverse events, and renal and hepatic parameters.

RESULTS

The total dose of morphine was significantly decreased in the propacetamol group compared to placebo (9.4 +/- 8.5 mg vs 17.6 +/- 12 mg; P < 0.001), arriving at a sparing effect of 46%. The evolution of pain intensity showed a similar pattern in the two groups. Global efficacy of treatment was rated significantly better by patients receiving the combination propacetamol + PCA morphine (87% of "good"/"excellent" ratings vs 65%; P = 0.01). Tolerability was comparable in the two groups. Eight patients in the propacetamol and 4 patients in the placebo group reported adverse events, of mild/moderate intensity, most commonly nausea/vomiting. Renal and hepatic parameters were also seen to be comparable.

CONCLUSION

These results confirm a significant morphine-sparing effect, significantly better scores in the final assessment by patients, and a good tolerability of propacetamol after orthopedic surgery. The drug may, therefore, represent a useful alternative to NSAIDs, as complementary drug to opioids, in the management of moderate/severe postoperative pain.

Crosstalk between normal and tumoral brain cells. Effect on sex steroid metabolism

The present article shows for the first time that two cell lines derived respectively from a rat glioma (C6 cell line) and from a human astrocytoma (1321N1 cell line) are able to convert testosterone and progesterone into their corresponding 5 alpha-reduced metabolites dihydrotestosterone and dihydroprogesterone. Moreover, both cell lines are also able to convert these metabolites further into their corresponding 3 alpha-OH derivatives, 5 alpha-androstan-3 alpha, 7 beta-diol (3 alpha-diol) and tetrahydroprogesterone. On the basis of these observations, the possibility that secretory products of normal and tumoral brain cells might be able to influence steroid metabolism occurring in the two glial cell lines previously mentioned as well as in fetal rat neurons and in neonatal rat type 1 astrocytes has been considered. To this purpose, cultures of the different cellular types have been exposed to the conditioned medium in which the other cells were grown. The results obtained indicate that: 1. Neurons are able to stimulate, in a statistically significant fashion, the formation of dihydrotestosterone (DHT), 3 alpha-diol, and tetrahydraprogesterone (THP) in C6 cells. 2. Type 1 astrocytes, on the contrary, are unable to modify steroid metabolism in C6 cells. 3. C6 cell product(s) decrease(s) the formation of DHP in type 1 astrocytes, without modifying that of DHT. 4. C6 cells do not influence the metabolism of testosterone (T) and progesterone (P) in neurons. In conclusion, the present observations show that the conditioned medium of normal neurons is able to increase the metabolism of testosterone and progesterone occurring in a tumoral glial cell line, and that the conditioned media of the two tumoral cell lines analyzed are able to decrease the conversion of P into DHP occurring in normal type 1 astrocytes. The surprising result that these conditioned media do not alter the formation of DHT is discussed. Work is presently in progress to identify the principle(s) responsible respectively for the activating and inhibiting actions here described.

Metabolism of steroids in pure cultures of neurons and glial cells: role of intracellular signalling

In the brain, the 5 alpha-reductase converting testosterone (T) is present both in neurons and in glial cells, even if it prevails in neurons; the 3 alpha-hydroxysteroid-dehydrogenase (3 alpha-HSD), the enzyme converting dihydrotestosterone (DHT) into 3 alpha-diol, is particularly concentrated in type 1 astrocytes. In glial cells, since the 5 alpha-reductase is activated by a cAMP analogue, PKA seems to be involved in the control of this enzyme, postulating that nervous inputs utilizing cAMP as the second messenger might modify the activity of this enzyme in glial cells. Moreover, the results indicate that, in type 1 astrocytes, both the 5 alpha-reductase and the 3 alpha-HSD are stimulated by the co-culture with neurons and by the addition of neuron-conditioned medium, suggesting that secretory products released by neurons might intervene in the control of glial cell function.

Pregnancy-induced changes in thyroid function: role of human chorionic gonadotropin as putative regulator of maternal thyroid

Marked changes in maternal thyroid activity occur in pregnancy. It has been suggested that hCG may stimulate maternal T4 secretion, given its in vitro thyrotropic activity ascribed to a significant degree of structural homology with TSH. In a longitudinal study of 32 normal pregnant women, we attempted to clarify the functional activity of the thyroid in early and late pregnancy and the possibility of a nonpituitary control on the thyroid. Total T4 and T4-binding globulin levels were increased from the first trimester onward. Free T4 levels did not differ in the first trimester from postpartum values, but were significantly decreased in second and third trimesters (P less than 0.001). A decrease in TSH levels was observed in the first trimester (0.72 +/- 0.09 vs. 1.23 +/- 0.12 mU/L; P less than 0.001), while second and third trimester values did not differ from those postpartum. A significant negative correlation (P less than 0.05) was observed between hCG and TSH levels in the earliest weeks (8-10) of the first trimester. No correlation was found between hCG and total T4 or free T4 levels. A stimulation of I- uptake in FRTL-5 cells was induced by first trimester serum, which also showed a different behavior at chromatofocusing, with a higher proportion of hCG eluting at acidic pIs compared to second trimester samples. However, neither hCG levels nor the amount of acidic hCG correlated with the thyroid-stimulating activity measured in vitro. Some correlation was found with the percentage of basic hCG (eluting at pI greater than 4.6), although these isoforms were equally present in first and second trimesters. The differing patterns of circulating hCG at various stages of gestation suggest that distinct hCG isoforms may regulate maternal thyroid activity.

Size heterogeneity of circulating growth hormone in acromegaly. "Big-big" GH forms are associated with inappropriately low IGF-I levels

Circulating GH consists of several molecular size species with different biological activity. A reduced sensitivity of some monoclonal antibodies towards high-molecular weight GH variants has been reported. The aim of the present work was to evaluate the molecular size species of circulating GH using Sephadex G-100 gel filtration chromatography in acromegalic patients and in normal subjects employing both RIA and an immunoradiometric assay for all GH determinations. In 6 normal subjects, studied under GHRH stimulation, little GH was 69.8 +/- 6% (mean +/- SD), big GH (44 kD) 26.4 +/- 6% and big-big GH (greater than 80 kD) 2.8 +/- 4%, in IRMA, with a good correspondence with RIA results (70.8 +/- 8, 27.0 +/- 4, and 3.2 +/- 2%, respectively). In 13 untreated acromegalic patients, studied in basal conditions, the little form constituted 76.2 +/- 7%, the big form 18.3 +/- 4%, which is significantly lower than in normals (p less than 0.05), and the big-big form 5.5 +/- 7%. Similar results were obtained with RIA. A clear elevation of big-big GH (21% for both in IRMA, and 15.7 and 27.8% in RIA) was found in 2 patients with IGF-I levels lower than expected on the basis of mean GH concentrations. The study was extended to an additional acromegalic patient, previously operated and irradiated on, characterized by discrepant serum GH levels in RIA (4.6 micrograms/l), and in IRMA (1.4 micrograms/l), and by normal IGF-I levels. Serum GH showed a lack of parallelism to standard GH in RIA, but not in IRMA. RIA immunoreactivity was almost completely composed (92%) of a high molecular weight GH form (greater than 90 kD), not recognized by IRMA. All IRMA immunoreactivity eluted with a Kav corresponding to 19-50 kD.

IN CONCLUSION

a. the three main molecular size isomers of serum GH are similarly recognized by IRMA and RIA methods in normal subjects. b. in acromegaly, both quantitative and qualitative modifications of the GH chromatographic profile may be present. In particular, increased amounts of big-big forms, whether or not recognized by monoclonal antibodies, have been observed. Their lower bioactivity, suggested by the normal or lower than expected IGF-I levels, can account for the discrepancy between serum GH levels and the clinical picture or IGF-I levels sometimes observed in acromegaly.

Maternal thyroid function in early and late pregnancy

Thyroid function was investigated during and after pregnancy in 12 healthy euthyroid women. During pregnancy, serum total T4 (TT4) levels were significantly elevated and nearly stable, while thyroxine-binding globulin (TBG) levels progressively increased till the 7th month. A slight elevation, though not significant, of free T4 (fT4) was recorded in early pregnancy. In the following months, fT4, free T3 (fT3) and the T4/TBG ratio progressively diminished, reaching a plateau at the 7th month. Serum TSH levels, measured by an ultrasensitive immunofluorometric assay, were comparable to postpartum values during the first trimester and showed a moderate upward trend with the progression of pregnancy. The evaluation of 24-hour TSH profiles was performed in 5 women during the first trimester of pregnancy. In all women, the circadian rhythm of TSH was present with a normal nocturnal surge, though anticipated in 1 case. In summary (1) during the first trimester of pregnancy, the increased thyroid activity does not seem to be only sustained by pituitary TSH which remains unmodified; the negative correlation between TSH and hCG levels might suggest that hCG also stimulates the gland to increase thyroid hormone output, and the presence of a normal TSH circadian rhythm indicates that the central mechanism of neuroregulation of the pituitary-thyroid axis is preserved in early pregnancy, and (2) in late pregnancy, a marked decrease in free thyroid hormone fractions is accompanied by serum TSH levels still in the normal range, indicating a modification of thyroid homeostasis which might recognize various etiological factors.

5 alpha-reductase activity in isolated and cultured neuronal and glial cells of the rat

The distribution of the 5 alpha-reductase, the enzyme which converts testosterone into its 'active' metabolite dihydrotestosterone (DHT), has been studied in neurons, astrocytes and oligodendrocytes isolated from the brain of male rats by density gradient ultracentrifugation and in neurons and glial cells grown in cultures. Purity of cellular preparations was examined by electron and light microscopy. Purified neurons, astrocytes and oligodendrocytes, obtained from the brain of adult male rats, are all able to form DHT from testosterone and consequently possess a 5 alpha-reductase activity. Among the 3 cell types studied, neurons appear to be more active than oligodendrocytes and astrocytes. Moreover, between the two population of glial cells, the oligodendrocytes seem to possess a slightly higher enzymatic activity than that present in the astrocytes. Neurons appeared more active in metabolizing testosterone than glial cells also in cell culture experiments. It is presently believed that the 5 alpha-reduction of testosterone to DHT provides one of the mechanisms through which the hormone becomes effective in the CNS. This is supported by the present findings, which indicate that neurons are the cell population in which the 5 alpha-reductase is more concentrated. However, the presence of a considerable 5 alpha-reductase activity in glial cells indicates that also non-neuronal cells might participate in androgen-mediated events occurring in the brain.

Testosterone metabolism in peripheral nerves: presence of the 5 alpha-reductase-3 alpha-hydroxysteroid-dehydrogenase enzymatic system in the sciatic nerve of adult and aged rats

Previous reports from this laboratory indicate that the 5 alpha-reductase, the enzyme which converts testosterone into its "active" metabolite 5 alpha-androstan-17 beta-ol-3-one (dihydrotestosterone, DHT) is highly concentrated in the white matter structures of the CNS, which are mainly composed of myelinated fibers. No studies have been performed up to now, in order to evaluate the possible presence of the 5 alpha-reductase activity in peripheral myelinated nerves. To this purpose the 5 alpha-reductase activity has been evaluated in the sciatic nerve of the rat and compared to that present in the cerebral cortex and in the subcortical white matter, a central structure mainly composed of myelinated fibers. The study has been performed in normal adult male rats (60-90-day-old) and in aged (20-month-old) animals. The data obtained in 60-90-day-old animals indicate the presence of an active metabolism of testosterone at the level of the sciatic nerve. In this structure, testosterone is actively transformed into DHT and 5 alpha-androstan-3 alpha, 17 beta-diol (3 alpha-diol); in the sciatic nerve, the formation of DHT is equal to that found in the subcortical white matter and higher than that found in the cerebral cortex. Moreover, at variance with what happens in CNS structures, where 3 alpha-diol is produced only in small amounts, in the sciatic nerve this metabolite is produced in amounts similar to those of DHT. The study in aged rats has shown that in the sciatic nerve, the formation of DHT and particularly that of 3 alpha-diol are much lower than in younger animals. No age-related variations in the 5 alpha-reductase activity in the cerebral cortex and in the subcortical white matter have been observed.

Kinetic properties of the 5 alpha-reductase of testosterone in the purified myelin, in the subcortical white matter and in the cerebral cortex of the male rat brain

The 5 alpha-reductase, the enzyme which converts testosterone into dihydrotestosterone (DHT), is present in several CNS structures of the rat. Recent reports from this laboratory indicate that the subcortical white matter and the myelin possess a 5 alpha-reductase activity several times higher than that present in the cerebral cortex. Moreover, previous ontogenetic observations indicate that in all cerebral tissues examined (including the myelin) the 5 alpha-reductase has a higher activity in immature animals. This study was performed in order to verify whether the differences in the 5 alpha-reductase activity on the various brain components might be due to the presence of different concentrations of the same enzyme or to different isoenzymes. To this purpose, the kinetic properties Km and Vmax were measured in the purified myelin as well as in homogenates of the subcortical white matter and of the cerebral cortex, obtained from the brain of adult (60-90-day-old), immature (23-day-old), and aged (greater than 20-month-old) male rats. The results indicate that the enzymes present in the myelin, in the subcortical white matter and in the cerebral cortex of adult male rats possess a very similar apparent Km (1.93 +/- 0.2, 2.72 +/- 0.73 and 3.83 +/- 0.49 microM respectively). On the contrary, the Vmax values obtained in the myelin (34.40 +/- 5.54), in the white matter (19.57 +/- 2.36) and in the cerebral cortex (6.47 +/- 1.03 ng/h/mg protein) of adult animals have been found to be consistently different. Very similar Km values were found in the myelin obtained from the brain of immature and very old rats (2.14 +/- 0.11 and 3.39 +/- 0.75 microM respectively). The Vmax measured in the myelin purified from the immature rat brain (62.25 +/- 4.52) showed a value which was much higher than that found in the myelin of adult animals (34.40 +/- 5.54); a Vmax (34.31 +/- 9.41) almost identical to that of adult animals was found in the myelin prepared from the brain of aged rats.

New biosynthetic anthracyclines related to barminomycins incorporating barbiturates in their moiety

Three new anthracyclines, FCE 21424 (2), FCE 24366 (3) and FCE 24367 (4), were isolated from culture broths of Streptomyces peucetius and its mutant strains after addition of sodium barbiturates during the fermentation. Structural assignment, achieved through spectroscopic and degradative studies, that the new anthracyclines had a common barminomycin-like structure incorporating different barbiturate moieties. The new anthracyclines were found to display outstanding cytotoxicity and remarkable potency "in vivo" against P388 ascitic leukemia.

Maturation of thyroid function in normal human foetuses

The functional maturation of an independent foetal thyroid activity was investigated in the present study. Serum concentrations of total T4, free T4, TSH and TBG were measured in 23 foetuses between 18 and 31 weeks' gestational age. Foetal samples were collected by transabdominal needling from the placental cord insertion. TT4, FT4, TBG and TSH levels significantly increased with gestational age. FT4 levels were comparable with the adult range by 28 weeks' gestation; TBG levels reached adult values at approximately 30 weeks, while TT4 was lower than adult levels throughout the whole period studied. TSH values were, in all cases, higher than the normal adult range. A significant positive correlation was present between TT4 and TBG, TT4 and TSH, and TBG and TSH levels; on the contrary, no correlation was demonstrated between FT4 and TSH levels. The TSH/TT4 ratio significantly decreased with gestational age. The results suggest an incomplete responsiveness of the foetal thyroid gland to TSH, while the feedback control system between pituitary and thyroid is operating at a different set point from that in post-natal life. The normal range of thyroid parameters established is of clinical relevance for the antenatal diagnosis, and eventual treatment of thyroid disorders that may seriously damage foetal development and maturation.

Studies of two thyrotrophin-secreting pituitary adenomas: evidence for dopamine receptor deficiency

Of 22 previously reported patients with TSH-secreting pituitary adenomas challenged with dopamine agonists, 18 showed no decrease in serum TSH. There have been few in-vitro studies of these rare tumours so the mechanism of the dopaminergic resistance has remained obscure. We describe two further patients with thyrotrophinomas; the first was thyrotoxic (T3 6.1 nmol/l, TSH 7 mU/l) and the second was diagnosed after radioiodine for presumed Graves' disease. The second patient had an alpha-subunit: TSH molar ratio less than unity (0.27). In-vivo TSH responses to TRH, bromocriptine and domperidone were compared with those of the resected tumour cells in vitro, the latter studied using a continuous perifusion system. Dopamine receptors were sought in membranes from each tumour using a radioreceptor assay employing 3H-spiperone. Patient 1 showed significant increases in serum TSH (7 to 13 mU/l) and alpha-subunit (18.7 to 385 ng/ml) after 200 micrograms TRH (i.v.) but patient 2 showed no such increases (TSH: 69 to 72 mU/l, alpha-subunit: 4.9 to 5.2 ng/ml). Neither patient showed a change in serum TSH following bromocriptine 2.5 mg (orally) or domperidone 10 mg (i.v.), though serum PRL responded normally. Serum TSH from patient 1 was of apparently normal molecular size but increased bioactivity (B/I ratio 3.8) and that from patient 2 was of increased molecular size but reduced bioactivity (B/I ratio 0.1). Tumour cells from each patient immunostained for TSH beta and alpha-subunit, and secreted TSH in vitro. The first showed dose-dependent TSH release after TRH (1-100 ng/ml) which could not be inhibited by dopamine (5 mumol/l) but the second was unresponsive to TRH in vitro. Neither tumour showed inhibition of TSH release by dopamine (5 mumol/l) or bromocriptine (0.01-10 nmol/l) and neither contained membrane-bound dopamine receptors. The results suggest that the dopaminergic resistance typical of most TSH-secreting pituitary adenomas may be due to altered or absent membrane-bound dopamine receptors.

Urinary metabolites of rifabutin, a new antimycobacterial agent, in human volunteers

1. Metabolites of the antimycobacterial agent 4-deoxo-3,4-[2-spiro-(N-isobutyl-4-piperidyl)]-(1H)-imidazo-(2,5-dihydro )- rifamycin S (rifabutin) were isolated from human urine after administration of a single oral dose of the drug. Some of these metabolites were identified by direct inlet mass spectrometry, 1H-n.m.r. spectrometry and, in two cases, by chromatographic comparison with reference compounds. 2. Unchanged drug, 25-O-deacetyl rifabutin and four other metabolites were identified in human urine. 25-O-Deacetyl rifabutin was the main urinary metabolite, other metabolites were characterized as oxidized, and oxidized-deacetylated derivatives. 3. Routes of metabolic transformation were: (a) deacetylation at position 25, (b) oxidation of methyl groups 31 or 32 or at the piperidine nitrogen, and (c) combination of these.

Effect of maternal hypothyroxinaemia during fetal life on the calmodulin-regulated phosphatase activity in the brain of the adult progeny in the rat

Calmodulin-regulated phosphatase activity was measured in the brain of 2-month-old rats born from hypothyroid and normal dams, using a fluorometric enzyme assay developed for this purpose. Calmodulin content was measured in the same brain regions by radioimmunoassay. Significant differences between groups in weight and protein content, basal phosphatase and calmodulin-regulated phosphatase activity were found. The brain region most affected was the cerebellum, where basal and calmodulin-regulated phosphatase activities, and protein content were increased. The data point towards a lasting effect of maternal hypothyroxinaemia on the brain function of the progeny.

Ontogenetic development of the 5 alpha-reductase in the rat brain: cerebral cortex, hypothalamus, purified myelin and isolated oligodendrocytes

In the central nervous system of the rat, the 5 alpha-reductase, the enzyme which converts testosterone into dihydrotestosterone, appears to be concentrated in the white matter and in particular to be associated with myelin. In order to verify whether a temporal correlation might exist between the formation of myelin membranes and the variations of the 5 alpha-reductase activity observed in the brain, the enzymatic activity was studied in the cerebral cortex and in the hypothalamus of male rat in the age range of 3-60 days, in myelin purified from animals of 15-60 days of life and in oligodendrocytes (i.e. in the cells responsible for the formation of the myelin) isolated from the brain of adult and very young rats (7th day of life, when the myelination process is not yet initiated). The results show that the formation of 5 alpha-androstane-17 beta-ol-3-one (DHT) in the cerebral cortex and in the hypothalamus has a peak activity in the first two weeks of life, before the beginning of the myelination process; purified myelin has an enzymatic activity always much higher than that present in the cerebral cortex and in the hypothalamus and shows a peak in the formation of DHT in the first period of myelinogenesis, on the third week of life. Finally the oligodendrocytes of young rats possess a much higher ability to convert testosterone into the 5 alpha-reduced metabolites than the oligodendrocytes of adult animals. A possible involvement of this enzyme in the myelin function may be hypothesized.

Testosterone 5 alpha-reductase activity in the rat brain is highly concentrated in white matter structures and in purified myelin sheaths of axons

Previous results obtained in this laboratory indicate that in the rat brain the 5 alpha-reductase, the enzymatic activity involved in metabolizing testosterone into 5 alpha-androstan-17 beta-ol-3-one (dihydrotestosterone), is particularly concentrated in the white matter. In the present experiments, this enzymatic activity was studied in the following white matter structures, which were microdissected using the punch technique of Palkovits: anterior commissure (CA), fornix (FX), habenulo-interpeduncular tract (HP), corpus callosum (CC), stria medullaris (SM), optic chiasm (CO), fimbria of the hippocampus (FI), cerebral peduncle (PC), pontine fibers (FP), cerebellar medulla (CMD) and corticospinal tract (TCS). Moreover brain myelin was isolated and purified by sucrose density gradient ultracentrifugation. The results obtained confirm that, in the rat brain, the enzymes involved in testosterone 5 alpha-reduction are preferentially localized in the white matter. However, clearcut differences in the metabolic activity exist between the different structures examined so far. DHT formation increases rostro-caudally, so that the highest activity has been recorded in the white matter structures punched at the level of pons (FP), medulla oblungata (TCS) and cerebellum (CMD). The high metabolic activity associated with the white matter structures appears to be linked to the presence of myelin, since the specific activity of the enzyme is particularly elevated in purified preparations of myelin sheaths.

Thyrotropic activity of crude hCG in FRTL-5 rat thyroid cells

The presence of thyroid stimulating activity in partially purified hCG was investigated using, as bioassay system, iodide uptake in rat thyroid FRTL-5 cells. The biological responses evoked by hCG were tested after neutralisation with monoclonal and polyclonal antisera to hTSH and hCG, and after fractionation on Sephadex G-100. The molar amounts of TSH and hCG in respective preparations were calculated assuming an activity of 30 IU/mg and 19 IU/mg, respectively, for bTSH and hTSH, and of 14,000 IU/mg for hCG. A dose-dependent response, paralleling that evoked by bTSH, was observed in a concentration range of 0.1-4 mumol/l hCG; 1 mumol of hCG was equivalent to 50 pmol of bTSH and 132 pmol of hTSH. The thyrotropic activity coeluted with hCG immunoactivity on Sephadex G-100. Incubation with monoclonal anti-hTSH antibodies did not affect the stimulatory ability of hCG preparation, indicating that it was not due to hTSH contamination. Similarly, a pretreatment with monoclonal and polyclonal anti-hCG antibodies did not significantly alter the iodide uptake response induced by hCG. These results indicate that the thyrotropic activity in partially purified hCG is not due to the presence of aspecific contaminants, but to a substance structurally related to hCG in terms of molecular weight. However, it appeared to differ from hCG immunologically, suggesting the hypothesis that minor modifications in the molecular structure may confer thyrotropic activity on hCG, altering its immunoreactive potency.

Differential distribution of the 5-alpha-reductase in the central nervous system of the rat and the mouse: are the white matter structures of the brain target tissue for testosterone action?

In the brain of several animal species testosterone is converted into a series of 5-alpha-reduced metabolites, and especially into 17-beta-hydroxy-5-alpha-androstan-3-one (DHT), by the action of the enzyme 5-alpha-reductase. The formation of DHT has never been evaluated in the white matter structures of the brain, which are composed mainly of myelinated axons. The experiments here described were performed in order to study, in the rat and the mouse, the DHT forming activity of several white matter structures, in comparison with that of the cerebral cortex and of the hypothalamus. Two sampling techniques were used in the rat: microdissection under a stereo-microscope from frozen brain sections of fragments of corpus callosum, optic chiasm and cerebral cortex; fresh tissue macrodissection of subcortical white matter, cerebral cortex and hypothalamus. Only macrodissection was used in the mice. The data show that, independently from the sampling technique used, there are considerable quantitative differences in the distribution pattern of the 5-alpha-reductase activity within different brain structures. Both in the rat and in the mouse, the enzyme appears to be present in higher concentrations in the white matter structures, than in the cerebral cortex and in the hypothalamus. The present results clearly show that the subcortical white matter and the corpus callosum are at least three times as potent as the cerebral cortex in converting testosterone into DHT. An even higher 5-alpha-reductase activity has been found in the optic chiasm. Further work is needed in order to understand the possible physiological role of DHT formation in the white matter structures.

Endocrine, biochemical, and morphological studies of a pituitary adenoma secreting growth hormone, thyrotropin (TSH), and alpha-subunit: evidence for secretion of TSH with increased bioactivity

A 40-yr-old man who had acromegaly and hyperthyroidism due to a GH/TSH-secreting pituitary adenoma is described. Serum free T4 was 2.8 ng/dl, free T3 was 1.1 ng/dl, and TSH was 1.2-1.5 microU/ml; the latter was measured in an immunoradiometric assay with a sensitivity of 0.07 microU/ml. Serum TSH was immunologically identical to standard TSH and did not decrease during a T3 suppression test. Serum free alpha-subunit and the molar alpha-subunit to TSH ratio were high (6.1 ng/ml and 31.2, respectively). TRH administration induced significant increases in both GH (+129%) and alpha-subunit (+156%) levels. Conversely, dopamine infusion resulted in a decrease in serum GH (-66%) and alpha-subunit (-43%) levels, and subsequent administration of the dopamine antagonist sulpiride induced significant increases in both GH and alpha-subunit (+393% and +106%, respectively). Similarly, somatostatin infusion inhibited GH (-43%) and alpha-subunit (-61%) secretion. Serum TSH levels were not affected by TRH, dopamine, or somatostatin. The biological to immunological activity ratio of serum TSH purified by immunoaffinity chromatography and measured in an adenylate cyclase assay was significantly increased compared to that in serum from hypothyroid or euthyroid subjects [biological to immunological activity ratio, 6.9 +/- 0.2 (+/- SD) vs. 4.4 +/- 1.1; P less than 0.001]. In gel chromatography, the apparent mol wt of the patient's TSH was smaller than that of the controls. After adenomectomy, all of the altered parameters of pituitary function became normal. Double gold particle immunostaining of the adenomatous tissue showed that all of the cells contained secretory granules positive for GH and alpha-subunit, while very few cells were positive for TSH beta as well as GH and alpha-subunit. These data indicate that in this patient serum TSH had an apparent mol wt smaller than that of normal TSH and an increased biological activity which, along with the autonomous TSH secretion, account for hyperthyroidism in the presence of low normal TSH levels; alpha-subunit originated from the same adenomatous cells that secreted GH but not TSH, thus explaining the in vivo observation that alpha-subunit responses to several agents were dissociated from TSH responses and parallel to GH responses; and TSH and GH were colocalized in a minority of the neoplastic cells.

Bicyclic compounds with potential antiulcer and/or antisecretory activity. II. 1(or 3),4,6,7-Tetrahydro-1(3)H-pyrano[3,4-d]imidazoles and 1(or 3),4,6,7-tetrahydro-1(3)H-thiopyrano[3,4-d]imidazoles

Owing to our current interest in synthesizing and evaluating the antiulcer and antisecretory activity of bicyclic compounds, a series of 1(or 3),4,6,7-tetrahydropyrano- and 1(or 3),4,6,7-tetrahydrothiopyrano-[3,4-d]imidazoles was synthesized and tested. The biological results were compared with those of some previously described 4,5,6,7-tetrahydroimidazo-[4,5-c]pyridine and 4,5,6,7-tetrahydrobenzimidazole derivatives.

New anthracycline glycosides obtained by the nitrous acid deamination of daunorubicin, doxorubicin and their configurational analogues

The new anthracyclines 7-O-(2,3,5-trideoxy-3-C-formyl-alpha-L-threo-pentofuranosyl)daunomyci none (8) and -adriamycinone (10) have been obtained upon nitrous acid deamination of daunorubicin and doxorubicin respectively. Deamination of the L-ribo analogue of daunorubicin (6) gave a mixture of 2,3,6-trideoxy-L-glycero-hexopyranosid-4-ulose (alpha-L-cinerulosyl) (11) and 2,6-dideoxy-alpha-L-arabino-hexopyranosyl (12) glycosides. The corresponding adriamycinone glycosides 13 and 14, obtained by deamination of the doxorubicin L-ribo analogue 7, were found to display an outstanding antileukemic activity in mice.

Novel rifamycins. III. Synthesis and antibacterial activity of 3-amidino- and of 4-aminoimidazolo[4,5-c]rifamycin derivatives

A number of semisynthetic rifamycin derivatives modified at position 3 and/or 4, belonging to general structures 2 and 4 (see Scheme 1), have been obtained. The synthesis and the biological activities of the new compounds are described. Compounds 4p and 4q display very good antimycobacterial activity in mice.

Excess of beta-subunit of thyrotropin (TSH) in patients with idiopathic central hypothyroidism due to the secretion of TSH with reduced biological activity

alpha-Subunit and beta-subunit of TSH were measured in the sera of five patients with idiopathic central hypothyroidism due to the secretion of biologically inactive TSH, in seven normal controls matched for bone age and sex, and in five subjects with mild primary thyroid failure before and after TRH (200 micrograms, iv) stimulation. Basal serum alpha-subunit concentration in patients did not differ from that in normal controls (mean +/- SD, 0.40 +/- 0.20 vs. 0.38 +/- 0.28 ng/ml; P, NS), whereas TSH and TSH-beta were significantly higher in patients (TSH, 1.51 +/- 0.74 vs. 0.59 +/- 0.53 ng/ml, P less than 0.025; TSH-beta, 0.56 +/- 0.18 vs. 0.10 +/- 0.02 ng/ml, P less than 0.001). The concentration of TSH-beta was also significantly higher in patients with central hypothyroidism than in subjects with mild primary thyroid failure (0.56 +/- 0.18 vs. 0.24 +/- 0.08 ng/ml; P less than 0.01), although serum TSH levels did not differ in the two groups (1.51 +/- 0.74 vs. 2.16 +/- 0.52 ng/ml; P, NS). alpha-Subunit was significantly higher in primary hypothyroid subjects (1.50 +/- 0.87, P less than 0.05 compared with patients with central hypothyroidism). After TRH, alpha-subunit, TSH, and TSH-beta net increases (peak) were significantly higher in patients with central hypothyroidism than in normal controls (alpha-subunit: 0.95 +/- 0.5 vs. 0.47 +/- 0.19 ng/ml, P less than 0.05; TSH: 7.1 +/- 3.1 vs. 2.9 +/- 1.8 ng/ml, P less than 0.005; TSH-beta: 0.89 +/- 0.35 vs. 0.22 +/- 0.18 ng/ml, P less than 0.005), whereas they did not significantly differ from those recorded in hypothyroid controls. The beta/alpha ratio, which was 1.67 +/- 0.86 in patients and 0.35 +/- 0.18 in normal controls (P less than 0.005), slightly decreased after TRH to 1.24 +/- 0.78 in patients, but remained unchanged in normal controls (0.39 +/- 0.1). After TRH the alpha-subunit peak occurred at 20 min both in patients and in controls, whereas TSH and TSH-beta peaked at 60 min in patients and at 20 min in controls. One patient was given oral TRH (40 mg/day for 4 weeks). The beta/alpha ratio fell from 1.85 to 0.13. Interestingly, serum thyroid hormones, which did not increase after iv TRH and after the first doses of oral TRH, showed a definite increase. Sera from two patients were filtered on Sephadex G-100: in one of them TSH-beta eluted in the same position as labeled reference standard, whereas in the other one radioimmunoassayable TSH-beta eluted near the void volume. The above data indicate that in patients with idiopathic central hypothyroidism due to biologically inactive TSH there is an excess of circulating TSH-beta and suggest that TRH is implicated in the secretion of TSH of full biological potency.

Species differences in the kinetics and metabolism of fenfluramine isomers

After single oral doses of racemic fenfluramine to man and animals (male CD-COBS Sprague-Dawley rat, male CD1-COBS mice and male beagle dogs) plasma and/or brain concentrations of the d- and l-isomers and their deethylated metabolite were measured by gas-liquid chromatography. In rat and mouse d-fenfluramine had a longer half-life (T 1/2) and gave a larger area under the curve (AUC) than the l-isomer. These differences were consistent with stereoselective N-deethylation of l-fenfluramine. Thus, in both species the plasma and brain AUC of the l-metabolite were double that of the d-form. In man and dog slight or no differences were seen between te kinetic and metabolic profiles of the isomers. Comparison of the plasma concentrations time curve of fenfluramine showed slower elimination in man than in the other species. The T 1/2 of the d-isomer was 2.6 hr in rat, 2.5 +/- 0.2 hr in the dog. 4.3 hr in the mouse and 17.8 +/- 0.9 hr in man. The deethylated metabolite norfenfluramine was present in plasma or brain, or both, of all the species examined as a major metabolite of the drug. At the oral doses of racemic fenfluramine tested the ration of the AUC for d-norfenfluramine to d-fenfluramine was 4.4, 2.0, 0.8, 0.3, and the dog, rat man and mouse respectively. The T 1/2 of the metabolite was longer than that of the parent drug in all these species. Similar studies with d-fenfluramine indicated that its kinetic profile was identical to that of d-fenfluramine administered in the racemic form. The l-isomer therefore does not change the absorption, distribution and metabolism of the d-isomer which should be considered as the active form.

Antileptazol activity and kinetic of CP 1414 S (7-nitro-2-amino-5-phenyl-3-H-,1,5-benzodiazepine-4-one) in the rat and mouse

The antileptazol effect of CP 1414 S (7-nitro-2-amino-3-phenyl-3H-1,5-benzodiazepine-4-one) a newly developed 1,5 benzodiazepine, lasts longer in mice than in rats. After intraperitoneal injection (10 mg/kg) brain levels of the drug were higher and persisted for longer in the mouse than in the rat. Although it cannot be excluded tht possible metabolites of CP 1414 S may contribute to the anticonvulsant effect of CP 1414 S, in both species the protective effect correlates well with the brain concentrations of the drug.

Antileptazol activity and kinetics of clobazam and N-desmethyl-clobazam in the guinea-pig

The kinetic profiles and antileptazol activity of clobazam and its main metabolite were compared to assess the metabolite's contribution to the anticonvulsant activity of clobazam in the guinea-pig. The metabolite was less effective than the parent compound in terms of doses and active brain levels. However, the metabolite formed after clobazam administration accounted for the persistence of antileptazol activity in this animal species.

Determination of plasma and brain concentrations of trazodone and its metabolite, 1-m-chlorophenylpiperazine, by gas-liquid chromatography

A sensitive and specific gas chromatographic procedure is described for the quantitation of trazodone and its active metabolite, 1-m-chlorophenylpiperazine (mCPP), in plasma and brain. After addition of internal standards, the samples were extracted with benzene and the extracts divided into two portions. One portion was evaporated to dryness, and residue dissolved in methanol and the solution injected into a gas chromatograph equipped with a nitrogen-selective detector, for trazodone quantitation. To the remaining half of the extracts, 100 microliter of heptafluorobutyric anhydride solution were added and the metabolite was measured as the heptafluorobutyryl derivative by electron-capture detection. Gas chromatography-mass spectrometry was used to confirm the specificity of the analyses. The kinetic profile of trazodone and its metabolite was investigated after oral administration of trazodone (25 mg/kg). The parent drug and its metabolite both accumulated in brain, reaching concentrations several times those in plasma. More mCPP than the parent compound entered the brain; the ratio of the area under the curve for trazodone to mCPP in plasma was about 4, whereas in brain it was only about 0.8.

Effects of increased central dopaminergic tonus on gonadotropin secretion

Gonadotropin secretion was investigated in 10 healthy volunteers (5 men and 5 women in the early follicular phase of cycle) by the following procedures: i) infusion of saline over 4 1/2 h period; ii) infusion of dopamine (DA) 4 microgram/kg bw/min over 4 h period; iii) oral administration of L-dopa (D) 100 mg plus carbidopa (C) 35 mg after 24 h pretreatment with C 50 mg every 6 h. This last pharmacological approach selectively enhances the central dopaminergic tonus. Blood samples were withdrawn every 15 min over 4 1/2 h period. No ultradian periodicity in LH and FSH secretion was observed. No significant modification in serum FSH levels was induced by any treatment at any time, while a significant decrease in serum LH concentration was observed from 45 to 240 min during DA infusion (-46.8%; p less than 0.005) and from 60 to 240 min after D + C administration -41.5%; p less than 0.05). These data demonstrate that, in humans, acute dopaminergic stimuli have an inhibitory action on LH release and suggest that this inhibition is exerted at the central level.