V-039 EXPANDED INDICATION FOR LAPAROSCOPIC INTRACORPOREAL RECTUS MUSCLE APONEUROPLASTY (LIRA) IN PARASTOMAL HERNIA

Aims

Laparoscopic intracorporeal rectus aponeuroplasty (LIRA) is a minimally invasive technique for the repair of incisional hernias from M2 to M4, but using the basic concepts of the technique, it allows an extended indication for other types of hernias such as suprapubic, lateral, or as in our case, the parastomal.

The aim is to present step by step the larparoscopic aponeuroplasty technique as an alternative for parastomal hernia repair, as a modification of the original LIRA-technique.

Material & Methods

We present a 56-year-old patient with a history of abdominoperineal resection in 2012, who presented a symptomatic parastomal hernia. Clinical examination and computed tomography (CT) showed a partially reducible type I parastomal hernia, 8×11cm.

Results

We begin by releasing adhesions and reducing the hernial sac, always with control of the vascular axis, avoiding ischemic events. We opened the peritoneum and the transversus muscle 1–2 cm from the edge of the defect. We closed the defect using the transversus muscle as well as the posterior rectus sheath. We reduce the pneumoperitoneum to adapt the mesh and fix it using non-absorbable tackers and fibrin glue coating.

Conclusions

The LIRA technique guarantees a reconstruction of the midline, reinforcing this area without tension in ventral hernias. Based on this condition, we apply the concepts in a parastomal hernia, the original technique being equally reproducible, providing the advantages of laparoscopic surgery in terms of less pain. and morbidity, and betting on the minimization of tension compared to primary closure, as well as less appearance of seroma.

V-048 EXPANDING INDICATION OF LAPAROSCOPIC INTRACORPOREAL RECTUS APONEUROPLASTY (LIRA) TO SUPRAPUBIC AREA: LIRA & TAPE

Aim

LIRA-technique is a minimally invasive technique described to repair M2–M4 primary and incisional hernias. Defects below this area (M5 –Suprapubic area) could be treated using the concept associated to LIRA, expanding the indication of this technique in combination with a transabdominal partially extraperitoneal (TAPE) repair. The aim of this video is to show the surgical steps combining LIRA & TAPE for M2–M5 ventral hernias.

Material & Methods

75-years-old-female patient with clinical examination and CT-scan showed a 9 cm width incisional hernia(W2), including the supraumbilical(M3), infraumbilical(M4) and suprapubic area(M5) with a total longitudinal length of 18 cm.

Results

The first step of the procedure is to open the peritoneum and posterior rectus sheath at 1–2 cm from the edge of the defect over the arcuate line. This flap allows following the dissection below arcuate line. At the suprapubic area, a bilateral peritoneal flap was done as indicated during the TAPE-repair until both Cooper ligaments are identified. Loop sutures were used for closing the defect, using the rectus muscle below the arcuate line, as well as the posterior rectus sheath above this line. A double-layer mesh is used in this case, being placed intraperitoneally.

Conclusions

The combination of LIRA & TAPE techniques provides an extension of the indication of concept associated to the LIRA for the repair of M5/W2 hernias, which could not be achieved using a conventional technique. Our initial experience with this technique, expanding the concept of LIRA to the suprapubic area, shows no recurrences and no postoperative morbidity.

Tubulin cofactor B plays a role in the neuronal growth cone

Tubulin cofactors, initially identified as alpha-, beta-tubulin folding proteins, are now believed to participate in the complex tubulin biogenesis and degradation routes, and thus to contribute to microtubule functional diversity and dynamics. However, a concrete role of tubulin cofactor B (TBCB) remains to be elucidated because this protein is not required for tubulin biogenesis, and it is apparently not essential for life in any of the organisms studied. In agreement with these data, here we show that TBCB localizes at the transition zone of the growth cones of growing neurites during neurogenesis where it plays a role in microtubule dynamics and plasticity. Gene silencing by means of small interfering RNA segments revealed that TBCB knockdown enhances axonal growth. In contrast, excess TBCB, a feature of giant axonal neuropathy, leads to microtubule depolymerization, growth cone retraction, and axonal damage followed by neuronal degeneration. These results provide an important insight into the understanding of the controlling mechanisms of growth cone microtubule dynamics.

Air pollution and cardiovascular admissions association in Spain: results within the EMECAS project

OBJECTIVE

To evaluate the short term effect of air pollution on cardiovascular admissions in 14 Spanish cities

METHODS

The period under study was from 1995 to 1999. Daily emergency admissions for all cardiovascular diseases (CVD) and heart diseases (HD) were obtained from hospital records, and the corresponding daily levels of particulates, SO2, NO2, CO, and ozone were recorded. The magnitude of association was estimated using Poisson generalised additive models controlling for confounding and overdispersion. For each cause, lagged effects, up to three days, of each pollutant were examined and combined estimates were obtained. For ozone the analyses were restricted to the warm period. One and two pollutant models were performed.

RESULTS

Associations were more consistent in lag 0 (concurrent day) and 1 (lag 0-1), except in the case of ozone where there was a more delayed relation (lag 2-3). For combined estimates an increase of 10 microg/m3 in the PM10 levels in lag 0-1 was associated with an increase of 0.9% (95% CI: 0.4 to 1.5%) in the number of hospital admissions for CVD, and 1.6% (0.8 to 2.3%) for HD. For ozone the corresponding estimates for lag 2-3 were 0.7% (0.3 to 1.0) for CVD, and 0.7% (0.1 to 1.2) for HD. An increase of 1 mg/m3 in CO levels was associated with an increase of 2.1% (0.7 to 3.5%) in CVD admissions, and 4.2% (1.3 to 7.1%) in HD admissions. SO2 and NO2 estimates were more sensitive in two pollutant models

CONCLUSIONS

A short term association between increases in daily levels of air pollutants and the number of daily admissions for cardiovascular diseases, with specificity for heart diseases, has been described in Spanish cities.

Native tubulin-folding cofactor E purified from baculovirus-infected Sf9 cells dissociates tubulin dimers

Tubulin-folding cofactor E (TBCE) is an alpha-tubulin-binding protein involved in the formation of the tubulin dimer and in microtubule dynamics, through the regulation of tubulin heterodimer dissociation. TBCE has also been implicated in two important related human disorders, the Kenny-Caffey and Sanjad-Sakati syndromes. The expression of TBCE as a recombinant protein in bacteria results in the formation of insoluble inclusion bodies in the absence of denaturing agents. Although the active protein can be obtained from mammalian tissues, biochemical studies of TBCE present a special challenge. To express and purify native TBCE, a recombinant baculovirus expression system was used. Native wild-type TBCE purified from Sf9 extracts was sequentially purified chromatographically through cation exchange, hydrophobic interaction, and high-resolution gel-filtration columns. Mass spectrometric analysis identified 30% of the sequence of human TBCE. A stoichiometric excess of purified TBCE dissociated tubulin heterodimers. This reaction produced a highly unstable TBCE-alpha-tubulin complex, which formed aggregates. To distinguish between the aggregation of tubulin dimers induced by TBCE and tubulin dissociation, TBCE and tubulin were incubated with tubulin-folding cofactor A (TBCA). This cofactor captures the beta-tubulin released from the heterodimer with a stoichiometry of 1:1, as previously demonstrated. The beta-tubulin polypeptide was recovered as TBCA-beta-tubulin complexes, as demonstrated by non-denaturing gel electrophoresis and specific antibodies directed against beta-tubulin and TBCA.

Role of cofactors B (TBCB) and E (TBCE) in tubulin heterodimer dissociation

Tubulin folding cofactors B (TBCB) and E (TBCE) are alpha-tubulin binding proteins that, together with Arl2 and cofactors D (TBCD), A (TBCA or p14) and C (TBCC), participate in tubulin biogenesis. TBCD and TBCE have also been implicated in microtubule dynamics through regulation of tubulin heterodimer dissociation. Understanding the in vivo function of these proteins will shed light on the Kenny-Caffey/Sanjad-Sakati syndrome, an important human disorder associated with TBCE. Here we show that, when overexpressed, TBCB depolymerizes microtubules. We found that this function is based on the ability of TBCB to form a binary complex with TBCE that greatly enhances the efficiency of this cofactor to dissociate tubulin in vivo and in vitro. We also show that TBCE, TBCB and alpha-tubulin form a ternary complex after heterodimer dissociation, whereas the free beta-tubulin subunit is recovered by TBCA. These complexes might serve to escort alpha-tubulin towards degradation or recycling, depending on the cell requirements.

Ventajas y peculiaridades del abordaje laparoscópico en el anciano

Both the age of the population and anesthetic and surgical techniques are advancing. Currently, 40% of surgical activity is performed in patients older than 65 years, who present a higher surgical risk than younger patients. The aim of treatment in the elderly is to provide the best possible quality of life, even though this represents a surgical challenge because of associated comorbidity and reduced cardiopulmonary reserve. From the moment at which laparotomy becomes an increased stress in the elderly, laparoscopic surgery can be particularly advantageous in this population. Therefore, minimally invasive surgery may have a greater impact in these individuals than in younger patients in reducing postoperative pain, cardiorespiratory complications, hospital stay, and recovery time before resuming physical activity. The recent advances in anesthesia, together with improved patient selection and perioperative cardiac care, and the general adoption of minimally invasive access have enabled more complex gastrointestinal procedures to be performed in the elderly. The factors that could influence the development of this type of approach in the elderly, as well as the precautions that should be taken, should be further analyzed.

[Prevalence of mild to moderate chronic kidney disease in the general population of Spain. Hortega study]

BACKGROUND

Although the epidemiology of subjects with end-stage renal disease is well-known in Spain, the prevalence of mild to moderate chronic kidney disease (CKD) in the general population is unknown. In order to measure this, it is necessary to carry out studies in the general population including those who are not health service patients. During epidemiology studies, the method of measuring glomerular filtration rate can change significantly the measurements of the prevalence of mild to moderate CKD.

METHODS

Between 1997 and 2000, we performed a multi-phase descriptive polistratified epidemiological transversal study. The section of public chosen was between the ages of 15 and 85 living in the health area of western Valladolid (Spain). We calculated creatinine clearance using four methods: serum creatinine concentration, creatinine clearance using 24-hour urine samples adjusting the volume to the expected creatinuria with the Walser formulas, using the Cockcroft-Gault (CG) equation and applying the Modification of Diet in Renal Disease (MDRD) study abbreviated formula. We classified the level of kidney function, according to the National Kidney Foundation-Dialysis Outcomes Initiative (NFK-DOQI) guidelines.

RESULTS

The instances of stages 2 and 3 CKD rise with age and are more common in women than men. This tendency is apparent in middle age and persons of 65 and above. Using the CG method, almost half the old women had a stage 3 CKD as opposed to a third of the men. If the measurement is performed using the abbreviated MDRD study, there are very few differences between the sexes. The prevalence of stage 3 CKD is similar (around 8%) but the prevalence of stage 2 CKD rises to 60% as opposed to 36% calculated using the CG equation. After comparing the results obtained with those of the third National Health and Nutrition Examination Survey Study (see table VII), the measurements of stage 3 CKD using the CG formula or by means of expected creatininuria coincide relatively, although the prevalence of stage 2 CKD is higher in persons of 65 and over. If we use the abreviated MDRD study, the prevalences increase by more than 20%.

CONCLUSIONS

The prevalence of stages 2 and 3 CKD is clearly influenced by the method of calculation used. The prevalence of stage 2 CKD affects at least a third of the general population while those affected by stage 3 CKD are between 3.3% and 8.5%.

The EMECAM project: a multicentre study on air pollution and mortality in Spain: combined results for particulates and for sulfur dioxide

OBJECTIVE

The EMECAM study is a collaborative effort to evaluate the impact of air pollution on mortality in Spain. In this paper the combined results are presented for the short term effects of particulates and sulfur dioxide on both daily mortality for all and for specific causes.

METHODS

The relation between daily mortality for all causes, cardiovascular diseases, and respiratory diseases, and air pollution for particulates (daily concentrations) and SO(2) (24 and 1 hour concentrations) was assessed in 13 Spanish cities for the period 1990-6. With a standardised method, magnitude of association in each city was estimated by Poisson regression in a generalised additive model. Local estimates were obtained from both single and two pollutant analyses. Lastly, combined estimates for each cause and pollutant were obtained.

RESULTS

For combined results, in single pollutant models a 10 microg/m(3) increase in the concentration of the mean of the concurrent and one day lag for black smoke was associated with a 0.8% (95% confidence interval (95% CI) 0.4 to 1.1%) increase in total mortality. The estimates for total suspended particles (TSPs) and particulate matter of aerodynamic diameter <10 microm (PM(10)) and total mortality were slightly lower. The same increase in concentrations of SO(2) was associated with a 0.5% increase in daily deaths. For groups of specific causes, higher estimations were found, specially for respiratory conditions. Peak concentrations of SO(2) showed significant associations with the three groups of mortality. When two pollutant analyses were performed, estimates for particulates, specially for black smoke, did not substantially change. The estimates for daily concentrations of SO(2) were greatly reduced, but, on the contrary, the association with peak concentrations of SO(2) did not show any change.

CONCLUSIONS

There is an association between mortality and pollution through particulates among city populations in Spain. Peak rather than daily concentrations of SO(2) were related to mortality. Results suggest that populations in Spanish cities are exposed to health risks derived from air pollution.

The concentration-response relation between air pollution and daily deaths

Studies on three continents have reported associations between various measures of airborne particles and daily deaths. Sulfur dioxide has also been associated with daily deaths, particularly in Europe. Questions remain about the shape of those associations, particularly whether there are thresholds at low levels. We examined the association of daily concentrations of black smoke and SO(2) with daily deaths in eight Spanish cities (Barcelona, Bilbao, Castellón, Gijón, Oviedo, Valencia, Vitoria, and Zaragoza) with different climates and different environmental and social characteristics. We used nonparametric smoothing to estimate the shape of the concentration-response curve in each city and combined those results using a metasmoothing technique developed by Schwartz and Zanobetti. We extended their method to incorporate random variance components. Black smoke had a nearly linear association with daily deaths, with no evidence of a threshold. A 10 microg/m(3) increase in black smoke was associated with a 0.88% increase in daily deaths (95% confidence interval, 0.56%-1.20%). SO(2) had a less plausible association: Daily deaths increased at very low concentrations, but leveled off and then decreased at higher concentrations. These findings held in both one- and two-pollutant models and held whether we optimized our weather and seasonal model in each city or used the same smoothing parameters in each city. We conclude that the association with particle levels is more convincing than for SO(2), and without a threshold. Linear models provide an adequate estimation of the effect of particulate air pollution on mortality at low to moderate concentrations.

Carcinoma of the extrahepatic biliary tree: analysis of 15 cases

AIM

to analyze the epidemiology, prognosis and treatment of those diagnosed as having cholangiocarcinoma of the extrahepatic biliary tree.

METHODS

a prospective study including all cases diagnosed over a period of 26 months. Fifteen patients with primary bile duct carcinoma were included.

RESULTS

the incidence rate was 3.23 cases/10(4). The tumor locations were: 40% proximal bile duct, 33% distal bile duct, and 27% mid-duct. The treatments used were: curative resection in 1 case (7%); palliative surgery in 3 cases (20%); internal drainage through a prosthetic biliary stent by endoscopic retrograde cholangiopancreatography in 6 cases (40%) and by percutaneous transhepatic cholangiography in 2 cases (13%); external bile drainage in case (7%), and in the remaining 2 patients (13%) no treatment was possible. The 1-month, 6-month and 10-month survival rates were 67%, 40% and 33% respectively. Factors associated with a worse survival in this study were age over 70 years and female sex. The worst prognostic location was the mid-duct compared to the distal and proximal thirds.

CONCLUSIONS

the incidence of the primary bile duct carcinoma is high in our population. The commonest location is the proximal bile duct. Curative surgical resection is possible in only a few cases, and thus the overall prognosis is very bad.

[The EMECAM protocol: an analysis of the short-term effect of air pollution on mortality. Estudio Multicéntrico Español sobre la Relación entre la Contaminación Atmosférica u la Mortalidad]

The aim of this study is to Mortality show the protocol of analysis which was set out as part of the EMECAM Project, illustrating the application thereof to the effect of pollution has on the mortality in the city of Valencia. The response variables considered will be the daily deaths rate resulting from all causes, except external ones. The explicative variables are the daily series of different pollutants (black smoke, SO2, NO2, CO, O3). As possible confusion variables, weather factors, structural factors and weekly cases of flu are taken into account. A Poisson regression model is built up for each one of the four deaths series in two stages. In the first stage, a baseline model is fitted using the possible confusion variables. In the second stage, the pollution variables or the time legs thereof are included, controlling the residual autocorrelation by including mortality time lags. The process of fitting the baseline model is as follows: 1) Include the significant sinusoidal terms up to the sixth order. 2) Include the significant temperature or temperature squared terms with the time lags thereof up to the 7th order. 3) Repeat this process with the relative humidity. 4) Add in the significant terms of calendar years, daily tendency and tendency squared. 5) The days of the week as dummy variables are always included in the model. 6) Include the holidays and the significant time lags of up to two weeks of flu. Following the reassessment of the model, each one of the pollutants and the time lags thereof up to the fifth order are proven out. The impact is analyzed by six-month periods, including interaction terms.

[The prevalence of asthma-related symptoms in 13-14-year-old children from 9 Spanish populations. The Spanish Group of the ISAAC Study (International Study of Asthma and Allergies in Childhood)]

BACKGROUND

Asthma is one of the more prevalent diseases in childhood. Geographical differences have been found but it is unknown if they are true or are a consequence of the different methods used in the study of asthma.

POPULATION AND METHODS

In 9 Spanish populations: Almería, Barcelona, Bilbao, Bahía de Cádiz, Cartagena, Castellón, Pamplona, Valencia and Valladolid, 27,407 children aged 13-14 years were interviewed using the asthma written and video questionnaires of the ISAAC protocol. Comparisons among geographical areas were performed using a cluster analysis and a Poisson regression model adjusting by gender.

RESULTS

The prevalence of resting wheezing using the video questionnaire was higher in males than in females (15.4% versus 12.6%) for wheezing ever. In the last year the prevalence of wheezing was 7.8% in males versus 7.0% in females. The analysis shows a group of centers with low prevalence of asthma symptoms: Valladolid, Almería, Castellón and Pamplona. Nevertheless there are also centers with higher prevalences as Bilbao, Barcelona and Bahía de Cádiz.

CONCLUSIONS

Prevalence of asthma and asthmatic symptoms is high in Spanish children aged 13-14 years. There are true geographical differences in Spain, being Valladolid, Almería, Castellón and Pamplona the areas with lowest prevalence.

Latex allergy in fruit-allergic patients

The purpose of this study was to investigate the prevalence of latex allergy in fruit-allergic patients, and to assess its clinical significance. Fifty-seven fruit-allergic patients and 50 non-fruit-allergic atopic patient controls were studied. All patients were questioned about conventional immediate symptoms after contact with latex products. Patients also underwent skin prick testing and determination of specific serum IgE to latex, as well as a screening test for environmental allergens. Immunologic latex sensitization occurred in 49/57 (85.9%) fruit-allergic patients, who showed a positive STP and/or CAP to latex, but in only two controls (P < 0.001). Six out of 57 (10.5%) fruit-allergic patients suffered from clinically relevant latex allergy. Symptoms included contact urticaria, angioedema, conjunctivitis, generalized urticaria, and moderate anaphylactic reactions. No control reported symptoms with latex products (P = 0.052). In all patients, clinical symptoms to fruits preceded a history of latex allergy. The fruits most associated were melon, peach, and banana. From our data, we conclude that there is a potential for allergic reactions to latex in patients with allergy to fruit. All patients with fruit allergy should be screened for individual risk of latex allergy.

Contact allergy to henna

Vegetable dyes can be recommended to patients sensitized to oxidative dyes due to their low allergenic power. The most important of these is henna which is used as a reddishbrown hair dye in some parts of the world. Different pathologies have been described caused by henna but the incidence of contact dermatitis appears to be extremely rare. In the present paper, we describe the case of a 30-year-old woman who developed allergic contact dermatitis following application of henna, but who did not work with the dye professionally.

[Relationship between maximum arterial pressure response to exercise and left ventricular hypertrophy in normotensive subjects]

INTRODUCTION AND OBJECTIVES

To determine whether normotensive persons with increases of systolic blood pressure with exercise have left ventricular hypertrophy and/or diastolic disfunction.

METHODS

A cross-sectional study, using echocardiography as a measurement of left ventricular hypertrophy and diastolic disfunction, was made among healthy population: 53 men, voluntary office workers from a firm and conscript army recruits, aged between 19 and 51 (mean 28, SD = 10.3) who were subjected to the exercise test and the echocardiography.

RESULTS

Twelve people (22.6%) with left ventricular mass index superior to 134 g/m2; and five (9.4%) with a systolic response during exercise higher than 210 mm of Hg. The multiple linear regression showed an association between maximum systolic blood pressure with exercise and the left ventricular mass index in the entire group of subjects (R2 = 18.4%: p < 0.01), but a modification effect with age was detected: no association was found (R2 = 2.8%; p = 0.37) among people under 25 (n = 30), but one was found among the older subjects (R2 = 28.8%; p < 0.01). Diastolic disfunction was associated with age, baseline heart rate and resting diastolic blood pressure (R2 = 64.3%; p < 0.01).

CONCLUSIONS

In normotensive subjects, the finding of an exaggerated blood pressure response to exercise could be related to left ventricular hypertrophy.

[Outbreak of measles at a vocational training school]

BACKGROUND

A measles outbreak which started in the technical institute Els Ports in Albocacer (Castellón), and involved nearby towns was studied.

METHODS

The outbreak was described using a retrospective cohort study to estimate the efficacy of the antimeasles vaccination (EV) by a questionnaire distributed in the institute. Response rate was 80.7%. A clinical definition of measles was used with EV being calculated by 2 different formulas. Antimeasles vaccination coverage (VC) in primary schools of the towns involved was also assessed.

RESULTS

The outbreak occurred from February to April 1992, including 13 cases of measles (mean age: 13.6 +/- 2.7 years). Eleven patients (84.6%) had not been vaccinated. The attack rate the above mentioned institute was 9.1% (8 cases/88 students) with VC of 40.9%. An association was found only between being vaccinated and not having measles, relative risk 0.07 (confidence limits [CL] 95%: 0.01-0.50). EV was 92.9% (CL 95%: 50-99%) using the traditional formula and 96.2% (CL 95%: 88.2-100%) using the new formula. The VC in the schools was 92.3%. Vaccination with the triple viral vaccine was recommended to susceptible individuals.

CONCLUSIONS

Despite specific vaccination measles continues to produce epidemics. A second dose of the triple viral vaccine is recommended for being included in the vaccination calendar between the age of 6 and 14 years.

Effects of noradrenaline and insulin on electrical activity in white adipose tissue of rat

An active change in membrane voltage responses to hyperpolarizing pulses has been identified by intracellular recording on an in vitro preparation of white adipose tissue. This change was characterized by a slow return to baseline at the offset of the pulses. Amplitude and duration of the slow return to baseline were dependent on extracellular K+ concentration, and were diminished by external application of Ba2+. Such properties suggest that this electrical response can be mainly due to activation of transient K+ conductances. The effects that noradrenaline and insulin have over the slow return to baseline have been also studied. While external addition of noradrenaline decreased amplitude and duration of this electrical response, insulin produced the opposite effect. These results suggest that noradrenaline and insulin could modulate K+ conductances in white adipocytes.

[Food poisoning by scombroid fish (tuna) in a communal dining room of a company]

We report a collective tuna fish poisoning which developed on June 10, 1988, in a staff dining room in Castellón. Twenty-one people were involved (attack rate 42.9%). The major symptoms were diarrhea, abdominal pain, headache, facial flushing and oral burning. The mean duration of the symptoms was 15 hours. The ingestion of tuna fish was significantly associated with the illness (p less than 0.001) when the other foodstuffs were controlled. Tuna fish had been defrosted at room air temperature during 14 hours. The analysis of several foodstuffs (there were no tuna fish remains available) and the food handling staff did not disclose pathogens. We discuss the etiology, pathogenesis, epidemiology and control of this type of food poisoning.

Effects of glucose on the metabolization of fructose and glycerol by isolated adipocytes from rat

Isolated white fat cells were incubated in medium containing (14C)-fructose (UL), supplemented with either 1 or 5 mM fructose, in the presence or absence of 5 mM glucose. The utilization of fructose for the formation of CO2, fatty acids or glyceride glycerol was very much dependent on its concentration in the medium. It was significantly inhibited by glucose only at fructose concentration of 5 mM. When the cells were incubated in the presence of (1(-14)C) glycerol, fructose produced a significant increase in the conversion of the tracer to CO2, fatty acids and glyceride glycerol, while glucose produced an increase in the formation of both CO2 and fatty acids, but a significant decrease of glyceride glycerol from the same labelled precursor. Glucose causes the effects of fructose, enhancing the uptake of labelled glycerol by the cells, to disappear.

Utilization of pyruvate, alanine and glutamate by isolated fat cells and their effects on glycerol metabolism

To study the metabolic interactions of different substrates in adipose tissue in vitro, isolated fat cells from fed rats were incubated in medium containing either (U-14C)-pyruvate, L-(U-14C)-alanine, L-(U-14C)-glutamate or (1(-14)C)-glycerol, and supplemented or not with 5 mM glucose or with non-radioactive pyruvate, alanine or glutamate (2 or 10 mM). The utilization of pyruvate for CO2 or fatty acid formation was greater than that of alanine and glutamate, both in the absence and presence of glucose. Glucose enhanced the formation of fatty acids from all the labelled substrates, decreased the synthesis of glyceride glycerol from pyruvate and glycerol, and enhanced it from alanine and glutamate. Pyruvate and glutamate enhanced the utilization of glycerol by the adipocytes and these effects were significantly reduced in the presence of glucose. Thus, the metabolic fate of the glycerol taken up by the cells varied according to the nature of the available substrates.