Ovarian thecoma: A very unusual cause of postmenopausal bleeding

We describe a 67-year-old woman with postmenopausal bleeding having ceased estrogen plus progestogen therapy nine months before. Transvaginal ultrasonography showed endometrial thickening with normal ovarian appearance. Hormonal studies revealed high estradiol and inhibin B levels but normal androgens and adrenal hormones. Magnetic resonance image demonstrated a 13-mm left ovarian tumour. Hysterectomy and bilateral salpingo-oophorectomy were performed, and the pathological study revealed an 8 mm ovarian thecoma. This case illustrates a very unusual cause of postmenopausal bleeding. We suggest a study protocol and discuss the differential diagnosis of this case.

THU0559 IMPLEMENTATION OF A TRIAGE SYSTEM IN A HOSPITAL WITH HIGH DEMAND FOR CARE

Background:

Our hospital has 4 Rheumatologists and is in charge of 425.000 inhabitants (1 rheumatologist per 106.250 inhabitants). In November 2017, there were 503 referrals from primary care waiting for a first visit with the rheumatologist. Given the impossibility of covering this number of waiting patients through normal operation, it was decided to implement a rapid access polyclinic that started in December of 2017.

Objectives:

To evaluate the effectiveness of a triage system in a center with high demand for care.

Methods:

Patients referred by the general practitioner were evaluated by a senior rheumatologist in a 10-minute consultation using a predefined interrogation, expanded case-by-case based on the criteria of each rheumatologist. According to the results of the interview, the situation of the patient was categorized into: urgent, normal rheumatology control or control in primary care. For urgent consultations, an early control polyclinic was created to evaluate these patients within the following 15 days. The usual consultations entered into the usual scheduling system. The pathologies that were considered to require control in primary care were assigned to a coordination polyclinic where the patients were evaluated by an internist, in charge of confirming the diagnosis, educating the patient, and, if applicable, refer to primary care. No patient was discharged immediately after the triage. We report the data of the first 136 patients.

Results:

The waiting time was reduced from a median of 275 days (IQR 66-591) to 46.5 (23-140). Refer to table 1 for full results. In 52.2% of referred patients the suspicion of a chronic autoimmune or inflammatory disease was described in the referral note. In these patients, when comparing with patients whose referral notes did not refer to an inflammatory or autoimmune disease, the waiting time for triage was significantly shorter, the percentage of patients who were discharged from rheumatology was significantly lower, and the percentage of patients in whom a chronic autoimmune or inflammatory disease was confirmed in the first control was significantly higher.

Table 1All patientsOnly those with suspected autoimmune or chronic inflammatory disease in referral notePatients referred for other reasons (fibromyalgia, arthralgia, myalgia, osteoporosis, etc.)pNumber (%)136 (100)71 (52.2)65 (47.8)NAAge,mean years (SD)51.8 (16.3)50.7 (16.4)53.1 (16.2)NSMen, n (%)24 (17.6)15 (21.1)9 (13.8)NSTime between referral and triage, median days (IQR)46.5 (23-140)34 (15.5-124.5)54 (28-441)0,017Triage resolutionUrgent control, n (%)92 (67.6)55 (77.5)37 (56.9)0,011Normal Control, n (%)25 (18.4)12 (16.9)13 (20)NSPrimary care coordination, n (%)19 (14)4 (5.6)15 (23.1)0,003Time between triage and first control, median days (IQR)21 (14-42)21 (12.5-41)26 (21-42)NSFirst control resolution, n (%)96 (70.6)54 (76.1)42 (64.6)NSDiagnosis confirmation, n (%)37 (38.5)26 (48.1)11 (16.9)0,028Continue control, n (%)41 (42.7)26 (48.1)15 (23.1)NSDischarge to primary care, n (%)18 (18.8)2 (3.7)16 (24.6)<0,001

SD: standard deviation; n: number; IQR: Interquartile range

Conclusion:

We consider this strategy as successful in reducing care times and identifying patients who require an early start of treatment and close control. Referral notes from primary care were generally adequate to identify patients who required to continue rheumatologist control.

References:

None.

Disclosure of Interests:

Sebastian Ibáñez Consultant of: Novartis, Paid instructor for: Bristol Myers, Speakers bureau: Abbvie, Francisca Valenzuela: None declared, Oriela Martinez: None declared, Omar Valenzuela Consultant of: Bristol Myers, Paid instructor for: Bristol Myers, Speakers bureau: Bristol Myers, Abbvie, Francisco Silva Consultant of: Roche, Speakers bureau: Roche, María José Villar: None declared, María Paz Poblete: None declared, Claudia Mardones: None declared

Dry eye is matched by increased intrasubject variability in tear osmolarity as confirmed by machine learning approach

OBJECTIVE

Because of high variability, tear film osmolarity measures have been questioned in dry eye assessment. Understanding the origin of such variability would aid data interpretation. This study aims to evaluate osmolarity variability in a clinical setting.

MATERIAL AND METHODS

Twenty dry eyes and 20 control patients were evaluated. Three consecutive osmolarity measurements per eye at 5min intervals were obtained. Variability was represented by the difference between both extreme readings per eye. Machine learning techniques were used to quantify discrimination capacity of tear osmolarity for dry eye.

RESULTS

Mean osmolarities in the control and dry eye groups were 295.1±7.3mOsm/L and 300.6±11.2mOsm/L, respectively (P=.004). Osmolarity variabilities were 7.5±3.6mOsm/L and 16.7±11.9mOsm/L, for the control and dry eye groups, respectively (P<.001). Based on osmolarity, a logistic classifier showed an 85% classification accuracy.

CONCLUSIONS

In the clinical setting, both mean osmolarity and osmolarity variability in the dry eye group were significantly higher than in the control group. Machine learning techniques showed good classification accuracy. It is concluded that higher variability of tear osmolarity is a dry eye feature.

Evaluación del almidón de papa (Solanum tuberosum) en la obtención de bioplástico

Los bioplásticos a partir de almidón, son productos innovadores con un gran potencial de desarrollo y altamente amigables con el medio ambiente; en tal sentido, se evaluó el almidón extraído de cinco variedades de papa categoría richi (Superior (S), ICA Capiro (IC), Betina (B), Parda Pastusa (PP) y Criolla (C)) para la obtención de bioplásticos. Para lo anterior, se extrajo el almidón por el método de decantación natural, se determinó sus propiedades fisicoquímicas como temperatura de gelatinización (Tg), índice de absorbancia (IA), índice de solubilidad (IS), poder de hinchamiento (PDH), proteína, amilosa y amilopectina teniendo en cuenta la norma ISO 6647. Los resultados de cada variedad se evaluaron con una matriz de priorización, posteriormente, se elaboró el bioplástico siguiendo la metodología realizada por (Meza, 2016) y validado con un diseño unifactorial, donde se evalúa la incidencia del porcentaje de almidón (3, 6, 8%) en la mezcla, como variables de respuesta resistencia y calibre con 2 réplicas. Los resultados indican que la variedad (B) tiene las mejores características con 64,125 °C para Tg, para IA 3.130 g gel/g, IS 18,75 g/ml, PDH 4.03, proteína 0.341 %, amilosa 20,751 mg/L y amilopectina 79,249 mg/L. El bioplástico obtenido de esta variedad presentó características de resistencia de 25.35 MPa y calibre 0.17 mm obteniendo las mejores características mecánicas del bioplástico. Se concluye que el almidón de papa de categoría richi tiene alta potencialidad para la generación de bioplástico.

Ahmed glaucoma drainage implant surgery in the management of refractory uveitic glaucoma: Long-term follow up

OBJECTIVE

To examine the long-term efficacy, safety and complications of Ahmed glaucoma drainage implant surgery in patients with refractory uveitic glaucoma.

METHODS

Retrospective review of consecutive cases of patients with refractory uveitic glaucoma who underwent Ahmed glaucoma drainage implant surgery between 2004-2014. Demographic characteristics of the study population, visual acuity, intraocular pressure (IOP), number of antiglaucoma medications and operative and postoperative complications were recorded. Complete success was defined as IOP≥5 and ≤18mmHg without any medication, as qualified success if IOP≤18mmHg with one or more medications. Patients with less than 12 months of follow-up were excluded.

RESULTS

21 patients (26 eyes) were included. The mean postoperative follow-up was 53.5±31 months. Eight eyes (30%) had at least one previously failed glaucoma surgery. IOP was reduced from a mean of 30.0mmHg to 14.0mmHg at the last follow-up visit (P<.001). The number of IOP-lowering medications was reduced from a median of 2.9 preoperatively to 1.1 at the last follow-up (P<.001). Overall, 7 eyes (27%) were classified as complete success, 13 eyes (50%) were considered as qualified success, and 6 eyes (23%) met the criteria for failure. The most common postoperative complication was hypertensive phase in 12 eyes (46%). Kaplan-Meier life-table analysis showed a cumulative probability of success after Ahmed glaucoma valve implantation of 65% at 84 months.

CONCLUSIONS

Ahmed glaucoma drainage implant surgery may be considered a long-term effective and safety surgical option for patients with refractory uveitic glaucoma.

High prevalence of Demodex spp. infestation among patients with posterior blepharitis: correlation with age and cylindrical dandruff

OBJECTIVE

To determine prevalence of Demodex spp. and infestation index (II) by the parasite among patients of different ages with blepharitis and to assess association with occurrence of cylindrical dandruff (CC).

MATERIALS AND METHODS

Prospective study including patients diagnosed with posterior blepharitis between 2013 and 2015, without previous acaricide treatment, was conducted by Fundación Oftalmológica Los Andes (Chile). Four eyelashes were randomly extracted from each eyelid for parasite detection. The II was calculated as the ratio between the total number of demodex specimens found in the total number of eyelashes removed. A semi-quantitative determination of the CC was performed.

RESULTS

A total of 178 patients (91 men, 87 women), with a mean age of 58.49±20.66 years, were included. It was found that 83.7% of patients were infested with Demodex folliculorum with a mean II of 0.96±0.84 mites/eyelash. The II was significantly higher in patients over 50 years (p<.0001). Patient age and II showed a Pearson correlation coefficient (R²) of 0.12 (p<.0001). CC was observed in 71.4% of patients, with those over 50 years-old showing significantly higher values. A positive correlation was also observed between the amount of CC and the II (R²=.33; p<.0001).

CONCLUSIONS

The prevalence of infestation by Demodex folliculorum is high in patients with posterior blepharitis. The II by the parasite is positively correlated with age and with the occurrence of CC on the eyelid border.

Tofacitinib versus etanercept or placebo in patients with moderate to severe chronic plaque psoriasis: patient-reported outcomes from a Phase 3 study

BACKGROUND

Tofacitinib is an oral Janus kinase inhibitor that is being investigated for psoriasis. Psoriasis impacts on physical and psychological well-being; improvements in health-related quality of life (HRQoL) with etanercept in psoriasis are well documented.

OBJECTIVE

To evaluate HRQoL with tofacitinib, vs. placebo or etanercept, in the Phase 3, randomized, placebo-controlled, non-inferiority, Oral-treatment Psoriasis Trial (OPT) Compare Study (NCT01241591).

METHODS

Adults with moderate to severe chronic plaque psoriasis were randomized 3:3:3:1 to tofacitinib 10 or 5 mg twice daily (BID), etanercept 50 mg twice weekly or placebo, for 12 weeks. Patient-reported outcomes (PROs) included Dermatology Life Quality Index (DLQI), Itch Severity Item and Patient Global Assessment of psoriasis.

RESULTS

At baseline, 83.4% (911/1092) of patients had a DLQI score ranging between 6 and 30, indicating a substantial burden of disease. By Week 12, 47.3%, 43.6% and 30.9% of patients in the tofacitinib 10 mg BID, etanercept and tofacitinib 5 mg BID groups, respectively, had a DLQI score of 0 or 1 (no effect of psoriasis on QoL) vs. 7.8% for placebo (all P < 0.0001). Tofacitinib significantly reduced itch vs. placebo (P < 0.05 both doses) and etanercept (P < 0.0001 both doses) within 1 day of starting treatment. Furthermore, reductions in itch were greater with tofacitinib 10 mg BID, vs. etanercept, at Weeks 2-12 (all time points P < 0.05). At Week 2, an Itch Severity Item score of 'little or no itch' was more frequent with tofacitinib 10 mg (68.6%) vs. etanercept (57.4%) and placebo (12.2%), and the PtGA response rate was significantly greater with tofacitinib 10 mg vs. placebo (P < 0.05).

CONCLUSION

Oral tofacitinib provided significant improvements across multiple PROs by Week 12. Improvements with tofacitinib 10 mg BID were comparable to etanercept, and improvements in itch were greater and more rapid with tofacitinib 10 mg BID.

[Conjunctival impression cytology in patients with normal and impaired OSDI scores]

PURPOSE

To describe goblet cell density and Nelson grading in different areas of the ocular surface using conjunctival impression cytology (CIC) among patients with normal and impaired Ocular Surface Disease Index (OSDI) scores.

MATERIAL AND METHODS

Patients (n=166) under assessment for dry eye were recruited between 2011 and 2012 and classified according to the OSDI score in 4 categories (normal and impaired). Cytological study (CIC plus Papanicolaou staining) using the Nelson grading system, with modifications in staging, and goblet cell counting were performed on the nasal, temporal, inferior, and superior bulbar conjunctival surfaces.

RESULTS

Nelson grading was significantly higher in patients with a severely impaired OSDI score (1.41±0.14) compared to normal patients (0.86±0.09) (P<.01). Goblet cell density was significantly reduced in patients with a severely impaired OSDI score (310.24±56.24 cells per sample) compared with normal subjects (497.31±50.07 cells per sample) (P<.001). Compared with the photoexposed bulbar conjunctiva, goblet cell density on the non-photoexposed conjunctiva was significantly higher both in patients with mild (P<.01) and moderate (P<.001) OSDI scores.

CONCLUSION

Patients with severely impaired OSDI scores have less goblet cells and a higher Nelson grade. Goblet cells are more abundant on the non-photoexposed conjunctiva.

Management of subluxated lens in young patients

OBJECTIVES

To evaluate visual outcomes in patients treated for lens subluxation. Secondary objectives are to report best corrected visual acuity (BCVA) in LogMAR and compare the outcomes of patients managed conservatively with those treated surgically.

METHODS

Retrospective comparison of BCVA in patients under 50 years-old with lens subluxation, managed conservatively or surgically.

RESULTS

A total of 49 eyes of 28 patients were included. Demographic characteristics were similar in both groups. Twenty eyes were treated surgically (40.8%) compared to 29 with medical treatment (59.2%). Marfan syndrome (79.6%) was diagnosed in 39 eyes. LogMAR BCVA post intervention was 0.35±0.31 for medical treatment and 0.39±0.32 for the surgical group, with no significant differences (P=.63). Improvements in LogMAR lines were 2.7±4.2 and 4.11±4.2 (P=.35), respectively. Two eyes in the surgery group developed ocular hypertension (0.04%), none with retinal detachment.

CONCLUSIONS

The final BCVA showed no significant differences in this group of patients. BCVA depends on the visual potential of the rehabilitated eye rather than a specific type of intervention.

Involvement of the transcription factor STAT1 in the regulation of porcine ovarian granulosa cell functions treated and not treated with ghrelin

The aim of our in vitro experiments was to study the role of the transcription factor STAT1 and the hormone ghrelin in controlling porcine ovarian function. The effects of treatment with ghrelin (0, 1, 10, 100 ng/ml), transfection-induced overexpression of transcription factor STAT1, and their combination on apoptosis (expression of apoptosis-related peptides caspase-3, BAX and anti-apoptotic peptide BCL2), proliferation (expression of proliferating cell nuclear antigene PCNA, proliferation-associated protein kinase MAPK/ERK1,2) and release of the hormones progesterone (P(4)), prostaglandin F (PGF) and oxytocin (OXT) in cultured porcine ovarian granulosa cells was evaluated using RIA, immunocytochemistry and SDS-PAGE-western immunoblotting. It was found that ghrelin, when given alone, increased the expression of proliferation-associated PCNA and MAPK/ERK1,2, decreased the accumulation of apoptosis-related substances caspase-3, BAX, BCL2, decreased P(4), and increased PGF and OXT release. Ghrelin tended to promote accumulation of STAT1 in both control and transfected cells, although in transfected cells ghrelin at 1 ng/ml decreased STAT1 accumulation. Transfection of porcine granulosa cells by a gene construct encoding STAT1 promoted the expression of STAT1 and apoptosis-related-BAX but the expression of BCL2 did not, and decreased the accumulation of proliferation-associated MAPK/ERK1,2 but not that of PCNA. It also promoted PGF and OXT but not P(4) release. Overexpression of STAT1 reversed the effect of ghrelin on STAT1, PCNA, PGF, OXT (from stimulatory to inhibitory), BCL2, P(4) (from inhibitory to stimulatory), prevented ghrelin effect on caspase-3 and BAX, but did not affect ghrelin's effect on MAPK/ERK1,2 expression. These results suggest that ghrelin directly affects porcine ovarian cells function - stimulates proliferation, inhibits apoptosis and affects secretory activity. Furthermore, they demonstrated the involvement of the transcription factor STAT1 in controlling these functions, the promotion of some markers of apoptosis (BAX), inhibition of some markers of proliferation (MAPK/ERK1,2) and stimulation of PGF release. Finally, the obtained data failed to demonstrate that STAT1 is involved in mediating the action of ghrelin on ovarian cell functions.

Transcription factor p53 can regulate proliferation, apoptosis and secretory activity of luteinizing porcine ovarian granulosa cell cultured with and without ghrelin and FSH

The aim of our in vitro experiments was to examine the role of transcription factor p53 in controlling the basic functions of ovarian cells and their response to hormonal treatments. Porcine ovarian granulosa cells, transfected and non-transfected with a gene construct encoding p53, were cultured with ghrelin and FSH (all at concentrations of 0, 1, 10, or 100 ng/ml). Accumulation of p53, of apoptosis-related (MAP3K5) and proliferation-related (cyclin B1) substances was evaluated by immunocytochemistry. The secretion of progesterone (P4), oxytocin (OT), prostaglandin F (PGF), and E (PGE) was measured by RIA. Transfection with the p53 gene construct promoted accumulation of this transcription factor within cells. It also stimulated the expression of a marker of apoptosis (MAP3K5). Over-expression of p53 resulted in reduced accumulation of a marker of proliferation (cyclin B1), P4, and PGF secretion and increased OT and PGE secretion. Ghrelin, when added alone, did not affect p53 or P4, but reduced MAP3K5 and increased PGF and PGE secretion. Over-expression of p53 reversed the effect of ghrelin on OT, caused it to be inhibitory to P4 secretion, but did not modify its action on MAP3K5, PGF, or PGE. FSH promoted the accumulation of p53, MAP3K5, and cyclin B1; these effects were unaffected by p53 transfection. These multiple effects of the p53 gene construct on luteinizing granulosa cells, cultured with and without hormones 1) demonstrate the effects of ghrelin and FSH on porcine ovarian cell apoptosis and secretory activity, 2) confirm the involvement of p53 in promoting apoptosis and inhibiting P4 secretion in these cells, 3) provide the first evidence that p53 suppress proliferation of ovarian cells, 4) provide the first evidence that p53 is involved in the control of ovarian peptide hormone (OT) and prostaglandin (PGF and PGE) secretion, and 5) suggest that p53 can modulate, but probably not mediate, the effects of ghrelin and FSH on the ovary.

The effect of obestatin on porcine ovarian granulosa cells

The aim of our in vitro experiments was to investigate the role of obestatin, a newly discovered metabolic hormone produced in the stomach and other tissues, in the direct control of ovarian cell proliferation, apoptosis and secretion. Porcine granulosa cells were cultured in the presence of obestatin (0, 1, 10 and 100ng/ml medium). The expression of intracellular peptides associated with proliferation (PCNA, cyclin B1, MAP kinase), as well as markers of apoptosis (Bax, p53, Caspase 3), were detected using immunocytochemistry and Western immunoblotting. Secretion of progesterone (P4), testosterone (T) and estradiol (E2) was measured by EIA. Addition of obestatin (1-100ng/ml) to the culture medium significantly stimulated the expression of PCNA and resulted in an increase in expression of cyclin B1 and MAPK. It also significantly increased the percentage of cells containing the apoptotic and anti-proliferating peptides p53, Caspase 3 and Bax. At 10 and 100ng/ml, obestatin promoted the secretion of P4, but not T or E2. Our results are the first demonstration that obestatin directly controls porcine ovarian cell functions: it can stimulate proliferation (accumulation of rPCNA, cyclin B1 and MAPK), apoptosis (expression of p53, Caspase 3 and Bax) and the secretion of progesterone.

Some endocrine traits of transgenic rabbits. II. Changes in hormone secretion and response of isolated ovarian tissue to FSH and ghrelin

In the present in vitro experiments we examined FSH- and ghrelin-induced changes in ovarian hormone secretion by transgenic rabbits. Fragments of ovaries isolated from adult transgenic (carrying mammary gland-specific mWAP-hFVIII gene) and non-transgenic rabbits from the same litter were cultured with and without FSH or ghrelin (both at 0, 1, 10 or 100 ng/ml medium). The secretion of progesterone (P4), estradiol (E2) and insulin-like growth factor I (IGF-I) was assessed by RIA. It was observed that ovaries isolated from transgenic rabbits secreted much less P4, E2 and IGF-I than the ovaries of non-transgenic animals. In control animals FSH reduced E2 (at doses 1-100 ng/ml medium) and IGF-I (at 1-100 ng/ml), but not P4 secretion, whereas ghrelin promoted P4 (at 1 ng/ml) and IGF-I (at 100 ng/ml), but not E2 output. In transgenic animals, the effects were reversed: FSH had a stimulatory effect on E2 (at 100 ng/ml) and ghrelin had an inhibitory effect on P4 (at 10 ng/ml). No differences in the pattern of influence of FSH on P4 and IGF-I and of ghrelin on E2 and IGF-I were found between control and transgenic animals. The present observations suggest that 1) both FSH and ghrelin are involved in rabbit ovarian hormone secretion, 2) transgenesis in rabbits is associated with a reduction in ovarian secretory activity, and 3) transgenesis can affect the response of ovarian cells to hormonal regulators.

Facile preparation of disulfide-bridged peptides using the polymer-supported oxidant CLEAR-OX

Formation of disulfide bonds in synthetic peptides is one of the more challenging transformations to achieve in peptide chemistry, in view of the possible formation of oligomeric by-products and other side reactions, as well as occasional solubility problems in aqueous oxidizing media. It was shown previously that 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB identical with Ellman's reagent), when attached to polyethylene glycol-polystyrene (PEG-PS), controlled-pore glass (CPG), or modified Sephadex supports, was an effective oxidizing agent that promoted disulfide formation under mild conditions. More recently, this work was extended to Cross-Linked Ethoxylate Acrylate Resin (CLEAR) supports, because of their compatibility with both organic and aqueous solvent mixtures. The resultant new tool, termed CLEAR-OX, was used to conveniently produce several model cyclic disulfides with improved purities and yields, when compared with solution oxidations. A particularly striking example was the gram-scale oxidation of a urotensin II antagonist peptide containing a hindered penicillamine unit.

Study of the influence of the pH media dissolution, degree of polymerization, and degree of swelling of the polymers on the mechanism of release of diltiazem from matrices based on mixtures of chitosan/alginate

The dissolution profiles of formulations based on mixtures of chitosan/alginate depend on the pH. It is possible to distinguish two processes: (a) a fast kinetic drug release up to 180 min, where the pH value changes from 1.17 to 2.21 and the drug released is controlled by the degree of polymerization and the quantity of chitosan in the formulation; (b) a low kinetic drug release between 210 and 480 min, where the pH value changes from 5.52 to 8.72 and the drug release from the matrix is controlled by the interpolymeric complex. In all formulations the order of release, according to Peppas's model in the range of fast kinetic drug release, was between 0.5 and 1.0. The mechanism of release was non-fickian diffusion, which corresponds to a coupling mechanism of diffusion and relaxation of the polymer.

[Use of amphotericin B in lipid emulsions: does it prevent its toxicity in critically ill patients?]

BACKGROUND

Amphotericin B is efficacious for the treatment of systemic candidiasis, however it has potentially serious toxic effects. Administration as lipid emulsions has been advocated to decrease its toxicity.

AIM

To compare the safety and tolerance of amphotericin B administered as lipid emulsion or dissolved in dextrose in water.

PATIENTS AND METHODS

Forty five patients with confirmed or highly suspected systemic candidiasis were studied. Between January 1996 and June 1997 amphotericin B was administered in dextrose in water to 17 patients (group 1). Between July 1997 and December 1998, the drug was delivered in lipid emulsions (Intralipid, group 2). Clinical and laboratory parameters (serum creatinine, urea nitrogen and potassium), were assessed daily.

RESULTS

Both treatment groups were clinically comparable and had the same survival. Accumulative amphotericin B dose administered was 343.2 +/- 197 and 414.6 +/- 518 mg respectively. Hypokalemia was more frequent in group 2 (52 and 25% respectively, p < 0.05). There were no differences in the outcome of renal function or other adverse reactions.

CONCLUSIONS

Administration of amphotericin B as lipid emulsions did not reduce its toxicity in critical patients (Rev Méd Chile 2000; 128: 1101-07).

Involvement of different Ca2+ pools during the canine bronchial sustained contraction in Ca2+-free medium: lack of effect of PKC inhibition

We evaluated the role of protein kinase C (PKC) in the sustained bronchial contraction (SBC) induced by carbachol (Cch) or histamine in a Ca2+-free medium and the possibility that each agonist uses a different Ca2+ store for this response. We studied third-order bronchi and airway smooth muscle (ASM) from first-order bronchi dissected free of cartilage and epithelium. Bronchial and ASM responsiveness to Cch or histamine were evaluated in Krebs solution (2.5 mM Ca2+) and in Ca2+-free medium. Cch and histamine induced an SBC in bronchial tissues in Ca2+-free medium. In ASM each agonist produced a transient contraction, but the response to histamine was much smaller. Cch induced a concentration-dependent accumulation of inositol phosphates (IPs) in both bronchi and ASM; however, histamine did not induce significant accumulation of IPs. Repeated exposure to histamine in bronchial rings abolished contractile responses in Ca2+-free media, but Cch added afterwards still produced a sustained contraction. This response was blocked when bronchial tissues were preincubated with 10 microM cyclopiazonic acid (CPA). Brief incubation of these preparations with a high EGTA concentration (1 mM) abolished the histamine-induced SBC. The SBC induced by Cch or histamine in Ca2+-free medium was not affected by the preincubation of the tissues with calphostin C, chelerythrine or staurosporine. We concluded that Cch mobilizes Ca2+ from two different sources during the SBC in Ca2+-free medium: from a CPA-sensitive one from sarcoplasmic reticulum (SR) and from a putative extracellular membrane Ca2+ pool sensitive to 1 mM EGTA, and neither process involved PKC activation. Histamine appeared to utilize the extracellular membrane pool only.

[Pharmacological principles in pregnancy]

Drug consumption during pregnancy is a widespread practice that may produce adverse effects on the developing fetus. The magnitude of drug disposition is influenced for maternal-fetal unit physiological changes. The maternal-fetal unit represents a unique pharmacological state with multiple compartments, wherein the mother-placenta-extra-amniotic membranes-amniotic fluid and fetus are each represented as a single compartment with different functions and genetics or cellular individual characteristics. It is a problem which should be focused on several perspectives including epidemiological, pharmacological and toxicological aspects. An understanding of these aspects is essential to rational and effective health public policy on prenatal care.

Estrogenic effects of the synthetic aminoestrogen 17 beta-(5-hydroxy-1-pentylamino)-1,3,5(10)-estratrien-3-ol (pentolame)

In this study, we investigated the effects of pentolame, a 17 beta-aminoestrogen derivative, upon coagulation, serum LH, pituitary progestin receptors, uterine weight, and endometrium morphological changes in the castrated female rat. Groups of animals were subcutaneously (s.c.) injected with either estradiol (E2) (0.1 up to 1000 micrograms/animal), pentolame (1 up to 1000 micrograms/animal), or the vehicle alone daily for 5 consecutive days starting 2 weeks following ovariectomy. Administration of pentolame (10 to 1000 micrograms/animal) increased significantly (p < 0.05) the blood clotting time when compared with that obtained in the group of control animals (EC50 582 micrograms). Pentolame (500 and 1000 micrograms/rat for 5 days) caused a significant inhibition (p < 0.01) of serum LH levels (IC50 860 micrograms), which remained suppressed until Day 5 post last injection. In addition, treatment with pentolame was able to restore in the castrated female rat the presence of specific estrogen-dependent progestin binding sites at the anterior pituitary level. The affinity constants and the number of binding sites of pentolame-induced progestin receptors were similar to those obtained with estradiol at equipotent doses (860 micrograms vs. 1 microgram/animal, respectively). Administration of the 17 beta-aminoestrogen derivative resulted in a significant increase in uterine weight (EC50 420 micrograms) and endometrial characteristics were indistinguishable from those observed in the group of rats treated with E2.

Estrogenic effects of p-hydroxybenzoic acid in CD1 mice

Xenobiotic estrogens in the environment or diet have received much attention as a possible source of certain hormonal disease states in human and wildlife. Therefore, the detection of estrogenic activity of any substance, especially those related to the food industry, is important. The estrogenic activity of p-hydroxybenzoic acid (PHBA), a compound related to a commonly used group of preservatives in food, cosmetic, and pharmaceutical preparations, was evaluated with immature and adult ovariectomized female mice (CD1) using two well-known bioassays. Subcutaneous administrations (s.c.) of different doses of PHBA were compared with estradiol (E2), and their effects on vaginal cornification and uterotrophic activities were evaluated. Different groups of animals were treated s.c. daily for 3 days with vehicle (corn oil, 0.3 ml/100 g), E2 (1 microgram/100 g), and PHBA (0.5, 5, 50, and 500 micrograms/100 g). Four days after treatment, PHBA produced a dose-dependent response on vaginal cornification and uterotrophic activity in both immature and adult ovariectomized mice. The relative uterotrophic potency of PHBA (500 micrograms/100 g) to E2 (1 microgram/100 g) was 0.0011 in immature mice and 0.0018 in ovariectomized animals.

A JAVA-based multimedia tool for clinical practice guidelines

We have developed a specific language for the representation of Clinical Practice Guidelines (CPGs) and Windows C++ and platform independent JAVA applications for multimedia presentation and edition of electronically stored CPGs. This approach facilitates translation of guidelines and protocols from paper to computer-based flowchart representations. Users can navigate through the algorithm with a friendly user interface and access related multimedia information within the context of each clinical problem. CPGs can be stored in a computer server and distributed over the World Wide Web, facilitating dissemination, local adaptation, and use as a reference element in medical care. We have chosen the Agency for Health Care and Policy Research's heart failure guideline to demonstrate the capabilities of our tool.

[Mathematics and the heart]

Mathematical modeling in biomedical sciences is particularly difficult because of the great amount of variables that the biological phenomena imply, the difficulty in observation and experimentation, and the scarceness of mathematical methods suitable for incorporating all of these variables. Even so, many mathematical models can be found in biology which include reduccionist, structural or integrative approaches. Theoretical models in biology are designed upon clearly defined purposes and may extent from the molecular level to the intact organism. For a model to be useful, its variables, levels and links must be very explicit. Observable and measurable aspects of the heart allow a modeling approach of this organ, in normal or in pathological conditions. A few examples are mentioned. Mathematical modeling of the heart may help orient experimental research, join existing data and theories and it may also be of assistance as therapeutic guidance.

Effects of alpha adrenergic stimulation on time independent potassium current of isolated ventricular myocytes

The role of alpha adrenergic receptor stimulation on ventricular electrical activity is controversial. The aim of the present paper was to study a wide range of concentrations of alpha adrenergic agonists on the electrical properties of guinea pig's heart isolated ventricular myocytes. The experiments were performed according to the single electrode voltage clamp technique. Phenylephrine and epinephrine (in the presence of propranolol) were used at concentrations from 1 x 10(-9) to 10(-5) M. It was observed that both agonists induce an increase in the time independent inward rectifying potassium current (IK1), that could explain the shortening of the action potential. All the observed effects were dose-dependent and disappeared during washout. These results could explain, at least partially, some of the electrical changes observed during ischemia.

[Effects of adenosine on automaticity and post-potential oscillations in Purkinje fibers of mammals]

The aim of the present paper was to study the effects of adenosine (ADO) on automaticity and after potential oscillations on canine cardiac Purkinje fibers. ADO concentrations from 10(-8) to 10(-5) M were used. The intracellular electrical activity was recorded with conventional microelectrodes. ADO increased during the first two minutes the basic cycle length (BLC) with concentrations higher than 10(-8) M, to a value 50% above control, later there is a progression to a steady state. The dose-response curve in the steady state is sigmoidal and resembles those of receptor occupation. The slopes of pacemaker potentials have a tendency to decrease along with the increase in BLC length. After potential oscillations decrease with 10(-8) M of ADO but not with larger concentrations. There results supports the hypothesis that ADO produces an increase in the time independent potassium current similar to the one described for atrial and ventricular myocytes. This effect probably depends on specific receptor stimulation. The biphasic time course suggests the existence of subtypes of A1 receptor with different dissociation constants and affinities but with similar actions. The idea that the ADO effects depend mainly on the potassium currents and not on I(f) is supported by the absence of a dose-dependent effects in the oscillatory after potentials.

Role of the Inward K Rectifier in the Repetitive Activity at the Depolarized Level in Single Ventricular Myocytes

The role of the inward K(+) rectifier in the repetitive activity at depolarized levels was studied in guinea pig single ventricular myocytes by voltage- and current-clamp methods. In action potentials arrested at the plateau by a depolarizing current, small superimposed hyperpolarizing currents caused much larger voltage displacements than at the resting potential and sometimes induced a regenerative repolarization. Around -20 mV, sub- and suprathreshold repetitive inward currents were found. In the same voltage range, small hyperpolarizing currents reversed their polarity. During depolarizing voltage-clamp ramps, around -20 mV there was a sudden decrease in the outward current (I(ns): current underlying the negative slope in the inward K(+) rectifier steady state I-V relation). During repolarizing ramps, the reincrease in outward current was smaller and slower. During depolarizing and repolarizing current ramps, sudden voltage displacements showed a similar asymmetry. Repetitive I(ns) could continue as long as the potential was kept at the level at which they appeared. Depolarizing voltage-clamp steps also caused repetitive I(ns) and depolarizing current steps induced repetitive slow responses. Cadmium and verapamil reduced I(ns) amplitude during the depolarizing ramp. BRL 34915 (cromakalim), an opener of the ATP-sensitive K(+) channel, eliminated the negative slope and I(ns), whereas barium increased I(ns) frequency (an effect abolished by adding BRL). Depolarization-induced slow responses persisted in an NaCl- Ca-free solution. Thus, the mechanism of repetitive activity at the depolarized level appears to be related to the presence of the negative slope in the inward K(+) rectifier I-V relation. Copyright 1994 S. Karger AG, Basel

Different mechanism for insulin induced and contraction induced increases in skeletal muscle glucose uptake

Glucose facilitated diffusion into cells depends on concentration gradients between intracellular and extracellular spaces and can be modified by several factors such as insulin and contractions. Calmodulin participates in the insulin induced recruitment of vesicles containing glucose transporter molecules and its inhibition by trifluoperazine blocks insulin increases in glucose uptake. In the present study we tested if calmodulin inhibition with trifluoperazine blocks hindlimb muscle glucose uptake increase induced by contractions. Trifluoperazine does not inhibit exercise induced increases in glucose uptake; therefore, the mechanisms by which insulin and functional activity increase glucose uptake are different.

Regulation by glucose availability of tension development and electrical activity in fetal and neonatal rat hearts

The aim of the present article was to study if changes in glucose availability modify the functional activity of the glucose-dependent developing heart. Our data indicate that a decrease in glucose availability increases tension development and action potential duration at early fetal stages. This fact could probably be explained by the enhancement of Ca2+ movements that regulate the number and turnover rate of membrane glucose transporters in muscle cells. The sensitivity to glucose availability decreases postnatally as the heart becomes fatty acid-dependent.