Parkinsonism and Parkinson's disease associated with long-term administration of sertraline

Sertraline, a serotonin reuptake inhibitor, has been used to treat depression and has rarely been associated to Parkinsonism. The disease usually appears in old people a few days after sertraline administration and disappears very quickly after its withdrawal. We report a case of a woman, 81-year-old, who presented with hemiparkinsonism after long-term administration of sertraline at a dose of 100 mg/day. The symptoms disappeared 3 months after the withdrawal of the drug. However, without further administration of the drug for 14 months, the patient presented with Parkinson's disease, but responded well to levodopa.

Diagnostic approach to inborn errors of metabolism in an emergency unit

OBJECTIVES

Our aim was to review the patients with a final diagnosis of inborn error of metabolism (IEM) who had previously required clinical attention at the emergency unit of our hospital over the last 9 years.

METHODS

From the 184 patients with IEM, we selected 53 patients who required clinical attention at the EU as a prior step that led to a definitive diagnosis. We analyzed the frequency of the various IEM, their clinical presentations, and basic biochemical abnormalities in decompensation.

RESULTS

We detected a predominance of neurologic signs (in 85% of our patients), followed by digestive symptoms (58.5%). Both were associated in 51% of patients. Vomiting and other digestive signs were observed in the same proportion as described in other series, but dehydration was only seen in three of our patients, probably because of early attention and fluid correction.

CONCLUSIONS

1) the diagnosis of an IEM has often been made after the first consultation at the EU, leading to hospitalization; 2) we should suspect an IEM in patients with neurologic abnormalities (eg, developmental delay, hypotonus or feeding difficulties), especially in those patients with multisystem involvement who appear with acute symptoms; 3) it is of the greatest importance that the appropriate sample collection be made before starting any treatment, because abnormal biochemical data can yield a first approach and allow the definitive diagnosis; and 4) the diagnosis of a patient with an IEM is not based on a single clinical or biochemical data but rather on all abnormal features taken together.

[Pre and perioperative factors determining early in-hospital mortality in patients over 75 years of age undergoing cardiac surgery]

INTRODUCTION AND OBJECTIVES

To know the in-hospital morbidity and mortality and the related factors in patients over 75 years old undergoing cardiac surgery.

PATIENTS AND METHODS

A retrospective analysis was carried out in 252 out of 2043 consecutive patients (129 female, 123 male) over 75 years of age (mean age 77.8 years; range 75 to 89 years) undergoing open heart surgery from january 1, 1994 to november 30, 1997. Isolated aortic valve replacement was performed in 128 patients, 78 underwent isolated coronary artery bypass grafting and 46 combined surgery. Preoperative determinants of morbidity and mortality were analyzed.

RESULTS

The overall hospital mortality was 15.1%, 13.2% in the aortic group, 12.8% in the coronary group and 23.9% in the combined surgery group. The overall morbidity rate was 38.6% and 25.8%, 34.2% in the aortic and coronary groups, respectively. Preoperative risk factors were prior surgery (p < 0.0004) and emergency operation (p < 0.04). In aortic valve replacement, NYHA class IV (p < 0.05), prior operation (p < 0. 01) and emergency surgery (p < 0.01) were determinant. Perioperative factors of early mortality were: prolonged cross-clamping > 60 min (p < 0.02), cardiopulmonary bypass time > 90 min (p < 0.002), need for inotropic drugs (p < 0.005) and postoperative complications (p < 0.00001). Mean postoperative length of hospital stay was 12.8 +/- 8. 5 days.

CONCLUSIONS

Despite the greater rate of early morbimortality in patients over 75 years of age, cardiac surgery may be performed avoiding emergency surgery, functional grade IV and prolonged length of surgery.

Biochemical analysis of a caveolae-enriched plasma membrane fraction from rat liver

We isolated and characterized a subcellular fraction derived from the blood-sinusoidal plasma membrane of hepatocytes enriched in caveolin and containing several of the molecular components described to be present in caveolae isolated from other cell types. A morphological study by electron microscopy revealed that it was composed of caveolae-attached membrane profiles. Immunoelectron microscopy of isolated fraction showed the specific labeling of internal caveolae membranes with anti-caveolin antibody. Finally, one- and two-dimensional electrophoresis and Western blotting were used for the biochemical analysis of this new rat liver plasma membrane fraction. From the biochemical and the morphological characterization, we conclude that the caveolae-enriched plasma membrane fraction is a plasma membrane fraction, which originates from specialized regions of the sinusoidal plasma membrane, enriched in caveolae.

EGF triggers caveolin redistribution from the plasma membrane to the early/sorting endocytic compartment of hepatocytes

In this study, we demonstrate that, in rat liver, epidermal growth factor (EGF) is responsible for the partial redistribution of caveolin-1 from the plasma membrane into the early/sorting endocytic compartment. Highly purified endosomes and plasma membrane fractions were isolated from control rat liver and from rats injected with EGF or pIgA for different times. Whereas in subcellular fractions from control hepatocytes most of caveolin was concentrated in the plasma membrane and the receptor-recycling fractions, after EGF injection there was a significant redistribution of caveolin toward the early/sorting (CURL) endocytic fractions. The recruitment of caveolin into the endocytic compartment was not induced by pIgA.

Cellubrevin is present in the basolateral endocytic compartment of hepatocytes and follows the transcytotic pathway after IgA internalization

The endocytic compartment of polarized cells is organized in basolateral and apical endosomes plus those endocytic structures specialized in recycling and transcytosis, which are still poorly characterized. The complexity of the various populations of endosomes has been demonstrated by the exquisite repertoire of endogenous proteins. In this study we examined the distribution of cellubrevin in the endocytic compartment of hepatocytes, since its intracellular location and function in polarized cells are largely unknown. Highly purified rat liver endosomes were isolated from estradiol-treated rats, and the early/sorting endosomal fraction was further subfractionated in a multistep sucrose density gradient, and studied. Analysis of dissected endosomal fractions showed that cellubrevin was located in early/sorting endosomes, with Rab4, annexins II and VI, and transferrin receptor, but in a specific subpopulation of these early endosomes with the same density range as pIgA and Raf-1. Interestingly, only in those isolated endosomal fractions, endosomes enriched in transcytotic structures (of livers loaded with IgA), the polymeric immunoglobulin receptor specifically co-immunoprecipitated with cellubrevin. In addition, confocal and immuno-electron microscopy identification of cellubrevin in tubular structures underneath the sinusoidal plasma membrane together with the re-organization of cellubrevin, in the endocytic compartment, after the IgA loading, strongly suggest the involvement of cellubrevin in the transcytosis of pIgA.

[Prevalence of asthma in Chilean students. Descriptive study of 24,470 children. ISAAC-Chile]

BACKGROUND

There is little information about the prevalence of asthma in Latin American children.

AIM

To determine the prevalence of asthma among Chilean school age children.

SUBJECTS AND METHODS

The prevalence of respiratory symptoms related to asthma in schoolchildren aged 7 and 13 years, coming from South Santiago, Central Santiago, Valdivia and Punta Arenas, was determined using the methodology of the International Study on Asthma and Allergies in Childhood (ISMC). A random sample of school children aged 6-7 and 13-14 years from each locality was selected. This resulted in 24)470 surveyed children (11,723 aged 6-7 years and 12,747 aged 13-14 years).

RESULTS

The current prevalence of wheezing ("wheezing in the last 12 months") ranged from 16.5% to 20.0% in children aged 67 years, and from 6.8% to 11.7% in children aged 13-14 years. The cumulative prevalence of asthma ("asthma ever"), ranged from 9.7% and 16.5% in the 6-7 years group and from 7.3% to 12.4% in those aged 13-14 years.

CONCLUSIONS

This study found much higher figures for prevalence of respiratory symptoms related to asthma in school children than those previously reported in this country, with a significant variability between centers (p < 0.05). The prevalence of asthma in Chilean schoolchildren is as high and variable as that reported in industrialized countries.

[Intravenous drug users serologic control: what may be prevented?]

OBJECTIVE

To report of IDU serologic control done in 1997 in comparison with another of 1990, in a Health-Care Area of Madrid, Spain, focussing to hepatitis B virus prevention.

PATIENTS AND METHODS

Cross-sectional study.

LOCATION

Fuenlabrada-Leganés, 400,000 inhabitants Health-Care Area in the Southeast of Madrid.

PATIENTS

233 IDU submitted for serological study during 1997 (mean age, 29.5; standard deviation, 6.8; 85.8% males).

INTERVENTIONS

HIV, HBV, HCV and Treponema pallidum; serological markers were done at Severo Ochoa Hospital and a search for previous reports since 1991. Study of HBV previous vaccination was done with HBsAb marker in HBV seronegative patients.

RESULTS

Prevalence: HBV 39.5% (IC = 33.2-46.1), HCV 49.3% (IC = 42.8-55.9), HIV 11.1% (IC = 7.5-16.1), syphilis 3.4% (IC = 1.5-7). Statistically meaning falls in rates were detected comparing them with results from 1990 (HBV: 67.5%; HCV: 75.1%; HIV: 50.1%; n = 261; p < 0.001). Only 5 (3.55%) out of 141 HBV seronegative patients showed HBsAb titres above 10 mU/I, although 55 (39%) of them had been tested for HBV previously. Nineteen (20.6%) out of 92 patients with HBV markers had previous seronegative reports and 3 of them suffered an acute viral infection.

CONCLUSIONS

We have seen a statistically meaning fall in seroprevalence of the studied agents although a low HBV vaccination rate was achieved.

The "early-sorting" endocytic compartment of rat hepatocytes is involved in the intracellular pathway of caveolin-1 (VIP-21)

The sinusoidal plasma membrane of the hepatocyte is organized into functional and structural microdomains whose origin, maintenance, and functioning are closely related with the endocytic compartment. Three different subcellular fractions, from rat liver, containing caveolin-1, the structural protein of caveolae, were morphologically and biochemically characterized. A caveolae-enriched plasma membrane fraction (CEF), contains large membrane structures surrounding attached internal plasmalemmal vesicles; the receptor-recycling compartment (RRC), contains tubules and vesicles with similar morphology to the internal vesicles observed by electron microscopy in CEF; and finally, caveolin-1 was also detected in early-sorting endosomes (CURL, compartment of uncoupling receptors and ligands). In this study, we show that following an intravenous administration of retinol-binding protein (RBP), there was a redistribution of caveolin-1 from the plasma membrane (CEF) to intracellular endocytic compartments (RRC and early-sorting endosomes). Thus, these results indicate that, in the hepatocyte, caveolae are dynamic structures actively interacting with the endocytic compartment.

Effect of heat treatment on anti-rotavirus activity of bovine colostrum

Rotavirus is the leading cause of infectious diarrhoea in infants and children throughout the world (Davidson, 1996). In developed countries, rotavirus is associated with significant morbidity, while it causes a high rate of infant mortality in developing countries (Blacklow & Greenberg, 1991).

At present there is no effective treatment or vaccine against human rotavirus. Although considerable effort is being put into developing such a vaccine (Molyneaux, 1995; Midthun & Kapikian, 1996), researchers are encountering difficulty in obtaining sufficiently broad protection against the great variety of human rotavirus serotypes (Kapikian & Chanock, 1985). Passive immunization has been tried as an alternative, and clinical trials have shown that oral intake of bovine colostrum containing anti-human rotavirus antibodies is effective in preventing rotavirus infection and transmission in experimental animals, infants and children (Davidson, 1996). Since cross reactivity has been found between bovine and human rotavirus strains (Kapikian & Chanock, 1985), a product containing specific antibodies against human or bovine rotavirus strains may exert a protective effect in human babies. Such a product would be a useful temporary measure while an effective vaccine is developed. Furthermore, these products could be valuable for immunocompromised patients in preventing rotavirus infections.

However, such products would be subjected to processes such as pasteurization or ultra high temperature treatments, so it would be necessary to know the effect of heat on the biological activity of the antibodies. We have previously studied the effect of heat on the structure of bovine colostrum immunoglobulins IgG, IgA and IgM and evaluated the kinetics of heat denaturation by measuring the loss of their ability to bind to specific antibodies directed against them (Mainer et al. 1997). In the present study we have investigated the effect of different heat treatments on the biological activity of immunoglobulins from bovine colostrum by measuring the virus-neutralizing activity (VNA) of heat-treated colostrum containing anti-rotavirus immunoglobulins against a bovine strain. In addition, we have studied the distribution of the VNA between the different classes of immunoglobulins of the anti-rotavirus colostrum.

Isolated endosomes from quiescent rat liver contain the signal transduction machinery. Differential distribution of activated Raf-1 and Mek in the endocytic compartment

In this study we identify the molecules involved in the MAPK signal transduction pathway (Ras, Raf-1, Mek, Mek-P and MAPK) in highly purified endosomal fractions isolated from rat liver. Biochemical analysis shows that only the early-sorting endocytic compartment contains activated Raf-1 and Mek. Finally, the exogenous administration of EGF led to redistribution of Raf-1 from the caveolin-enriched plasma membrane into the endosomes.

MR cholangiography in primary sclerosing cholangitis

OBJECTIVE

The purpose of this study was to evaluate the ability of MR cholangiography to reveal the characteristics of biliary abnormalities found in primary sclerosing cholangitis.

CONCLUSION

Our results suggest that MR cholangiography could be useful in the diagnosis of primary sclerosing cholangitis. Slightly dilated peripheral bile ducts unconnected to the central ducts in several hepatic segments are a characteristic MR sign of primary sclerosing cholangitis. However, other studies are necessary to establish the usefulness of MR cholangiography in relation to other imaging techniques for evaluating primary sclerosing cholangitis.

Heritability of running economy: a study made on twin brothers

Running economy (RE), defined as the steady-state of oxygen uptake (VO2) for a given running velocity, is a factor of sports performance the genetic component of which has seldom been reported to date. We studied this component using a heritability index (HI) in a group of 32 male twins, 8 monozygotic (MZ) and 8 dizygotic (DZ) pairs, all sportsmen with similar perinatal and environmental backgrounds. Zygocity was determined by the identity of erythrocytic antigenic, protein and enzymatic polymorphism, and human leucocyte antigen serologic types between co-twins. The subjects exercised twice on a treadmill, once until exhaustion and again at submaximal intensities. Pulmonary gas exchange was measured continuously using an automatic analyser system during both tests. Blood samples were obtained during the recovery period to determine lactate concentrations. No significant differences were observed between MZ and DZ, in respect of RE at any speed or in maximal VO2 relative to body mass. Nevertheless, significant HI (P < 0.05) was found in maximal lactate concentrations (HI=0.75) and in respiratory equivalent for oxygen at two speeds, 7 km x h(-1) HI=0.71) and 8 km x h(-1) (HI=0.79), differences which probably suggest that there are differences in RE. In conclusion, we did not detect a genetic component in RE or in maximal oxygen uptake, but a genetic component for markers of anaerobic metabolism was present.

Congenital hepatic fibrosis: findings at MR cholangiopancreatography

OBJECTIVE

This study describes the MR imaging features of congenital hepatic fibrosis in four children who were examined with MR cholangiopancreatography.

CONCLUSION

MR cholangiopancreatography effectively reveals biliary cysts, dilatation of intrahepatic bile ducts, and polycystic kidney disease, findings often associated with congenital hepatic fibrosis. This diagnosis should be suspected when these biliary and renal abnormalities are associated with hepatosplenomegaly in a patient with normal liver function.

Effect of heat treatment on the antigen-binding activity of anti-peroxidase immunoglobulins in bovine colostrum

After intramammary immunization with horseradish peroxidase, bovine colostrum containing anti-peroxidase immunoglobulins (Ig) was obtained. Thermoresistance of the antigen-binding region of these Ig was studied using a direct competitive ELISA. This technique is based on the competition between the anti-peroxidase IgG coated to the plate and the anti-peroxidase IgG contained in the colostrum to bind peroxidase, the antigen, and the enzyme responsible for development of the color of the assay. Thus, the degree of denaturation of the antigen-binding region in the IgG molecule can be determined because this region is directly involved in the assay. The kinetic and thermodynamic parameters for heat induced denaturation of IgG in colostrum were determined over a temperature range of 69 to 81 degrees C. The denaturation of IgG was best described assuming an apparent reaction order of 1.5. D values, the time required to reduce the antigen-binding activity of IgG by 90%, were 8504, 1387, 285, and 152 s at 69, 72, 77, and 81 degrees C, respectively. Similarly, Z value, the degrees necessary to reduce the D value in one logarithmic cycle, was estimated to be 6.6 degrees C, and the activation energy value was 386.83 kJ/mol. These results should be taken into account in the design of heat treatments of milk in order to preserve the biological function of Ig.

Interaction of mercury with human and bovine milk proteins

The interaction of inorganic mercury with human and bovine milk proteins was studied. Gel filtration chromatography of skimmed milk and whey incubated with mercury showed that, in human milk, mercury was mainly bound to caseins, while a low proportion was bound to albumin. In bovine milk, mercury was associated with two protein fractions, caseins and beta-lactoglobulin. Furthermore, it was shown by electrophoresis that mercury induced the formation of dimers of beta-lactoglobulin. Thus, in both human and bovine milk, mercury possessed greater ability to interact with milk proteins than to the low-molecular-weight substances. However, the pattern of mercury distribution was different between the milk of these two species.

Is physical training a good synchronizer of the performance?

Whether changes in the training schedule are capable of modifying the daily pattern of performance has been studies. Twelve swimmers were selected to determine their performance in 25 meter crawl races. Their body temperature was also measured. This group was subsequently divided into 3 subgroups: Sub-group 1, made up of 2 subjects who acted as the control subgroup, trained only in the afternoon; Sub-group 2, composed of 5 subjects, trained only in the morning; and Subgroup 3, also made up of 5 subjects, trained in the afternoon but with an additional session of 10 min of swimming in the morning. All subjects followed their corresponding training pattern for three weeks after which they were subjected to a second study or testing day. Thereafter, they all trained one more week according to the same habitual schedule in the evening; after that, they were tested again. A significant variance in the performance time was observed throughout the day (a maximum performance being observed at around 20:30 h), although the changes introduced in the training schedule did not modify the curve of performance.

Could the A2A11 human leucocyte antigen locus correlate with maximal aerobic power?

1. The power of the aerobic metabolic pathway correlates well with successful physical performance in endurance sports events. The ability to alter the pathway through training presents well-known limitations, and consequently a good genetic endowment is essential to participate in elite sporting activities. 2. In 32 subjects (16 healthy pairs of male twin sportsmen, 8 monozygotic and 8 dizygotic) zygosity was determined by means of the genetic analysis of human leucocyte antigen (HLA) system specificities at class I and II loci and other genetic variants. The subjects performed a progressive exercise test on a treadmill to ascertain the maximal oxygen uptake (VO2max), measured by an automatic breath-by-breath analyser. We have considered the relationship between the A, B and C loci of the HLA system and VO2max. 3. We found a high correlation between the presence of both HLA A2 and A11 and VO2max. In the A2A11 group (n = 6) we found a VO2max (mean +/- SD) equal to 71 +/- 4 ml min-1 kg-1. The group without this pair of alleles (n = 26) showed a much lower aerobic power (58 +/- 5 ml min-1 kg-1). Differences between the two groups were found to be largely significant (P < 0.001). It is noteworthy that in two pairs of dizygotic twins, the higher VO2max value corresponded to the twin with the A2A11 allele. 4. The very marked concordance between the presence of the A2A11 locus of the HLA system and the VO2max could be of great interest for the identification of outstanding performers.

[Prevalence of hepatitis E virus antibodies in blood donors and other population groups in southern Chile]

Little is known about hepatitis E virus (HEV) prevalence in South American countries. Anti-HEV was studied in 1,773 subjects from 1,360 blood donors of 3 cities in Chile, 72 in health care workers, 241 inmates in state jails, and in 100 Araucanian indians. Anti-HEV was detected in 109 out of 1,360 (8.0%) total donors (6.3%, 6.1%, and 18.8% from the cities of Valdivia, Osorno and Puerto Montt respectively); 9 out of 72 (12.5%) health care workers; 18 out of 241 (7.5%) inmates, and 17 out of 100 (17%) Araucanian indians. Prevalence of anti-HEV was not related to age and sex. Hepatitis E is an endemic infection in some population groups of Southern Chile, associated to environmental pollution, crowding and low socioeconomic level.

Is the post-lunch dip in sprinting performance associated with the timing of food ingestion?

To detect whether the drop in performance around lunch has any direct association with the time of food ingestion, a group of 8 sprinters were studied for 5 consecutive Saturdays. On each testing day, the times achieved during 80 meter sprints performed at eight different times of the day separated by 2 hour intervals were recorded. The 1st and 4th testing days, had identical sleep and mealtime schedules, and were therefore considered "control days", while on the 2nd and 3rd testing days the schedule was brought forward ("advanced") or backward ("delayed") by 2 hours respectively. On the 5th testing day the sleep-wake cycle was brought forward 2 hours without changing the mealtime schedule. A post-lunch dip (PLD) was detected on all testing days although at different times. No significant differences in performance were observed between days 1 and 4 while there were differences in performance during the other testing days. It is worth pointing out that PLD occurred at about 15:00 h on the control days, with significant differences between the 2nd (p < 0.05) and 3rd days (p < 0.05), and with the deterioration in performance starting at 15:00 h on the 3rd day despite the fact that lunch had been served at 16:00 h. In conclusion, PLD does not appear to be directly linked to the time of lunch, although lunch itself could potentiate its effects. It is also worth mentioning the fact that this deteriorating effect does not occur after any other meals of the day.

Influence of sleep and meal schedules on performance peaks in competitive sprinters

The influence of sleep and meal schedules on performance in short distance running was assessed in a group of 8 national-class competition male sprinters. They were tested on Saturdays for five consecutive weeks. On each testing day, the performance time for an 80 m sprint was registered on eight different occasions during days 1 and 4, on 9 occasions on days 2 and 5, and on 7 occasions on day 3. On control days (days 1 and 4) performance gradually improved during the morning up to 13:00 h, decreased at 15:00 h, and again improved thereafter, with a maximum peak performance at 19:00 h. On day 2, in which sleep/wake cycles and meal-times were advanced for two hours, and on day 3, in which timetables were delayed for two hours, maximum peak performance was observed at 17:00 h and 21:00 h, respectively. At the time of maximum peak performance on both days a statistically significant improvement was observed as compared with the control day (day 2, p < 0.01; day 3, p = 0.001). On day 5, in which only the sleep/wake cycle was advanced for two hours, performance in the afternoon and evening was similar to that recorded on days 1 and 4. We observed that easy manipulation of sleep and meal schedules would allow competitive sprinters to synchronize peak power output with the time of the athletic event, increasing the chances for improvement in performance.

[Preoperative and postoperative chemotherapy of osteogenic sarcoma of the limbs in children]

BACKGROUND

A preoperative and postoperative chemotherapy regimen was applied to nonmetastatic osteosarcoma of the extremities in patients under 16 years of age to prevent the progress to metastatic disease and reduce the volume of the primary tumor in order to assess a conservative surgery.

PATIENTS AND METHODS

A modified T-10 chemotherapy regimen was used before surgery, including high dose methotrexate, vincristine, bleomycin, cyclophosphamide and dactinomycin. After surgery patients with a grade of tumor necrosis > 90% received the same regimen up to 45 weeks of treatment. For the cases with necrosis < 90%, this regimen was substituted by adriamycin and cisplatinum. Survival was studied in relation with age, sex, tumor site, levels of alkaline phosphatase and LDH, surgical treatment and tumor necrosis in the surgical specimen after preoperative chemotherapy. Uni and multivariate analysis were performed.

RESULTS

Twenty seven patients with ages ranging from 5 to 15 years (median 11 years) were treated. The most common site of primary tumor was femur, followed by humerus and tibia. In 9 cases (33%) tumor necrosis was > 90%. Consecutive surgery was performed in 20 patients and 7 suffered amputation or disarticulation of the extremity. Twenty patients remain alive and disease-free at a median follow-up of 84 months. The probability of disease-free survival at 50 months is 71%. The only factor which influenced significantly the survival was the grade of tumor necrosis. Survival was 100% for the 9 patients with necrosis > 90% and 53% for the 18 cases with necrosis > 90% (p = 0.022).

CONCLUSIONS

Preoperative and postoperative chemotherapy achieve disease-free survival in more than two thirds of patients with nonmetastatic osteosarcoma of the extremities and allow a non mutilating surgical treatment in the majority of them.

Cadmium uptake by Caco-2 cells. Effect of some milk components

The effect of some milk components on the cellular uptake of cadmium has been studied using a human intestinal cell line (Caco-2). Cadmium uptake by Caco-2 cells increased with the concentration of this metal in the culture medium, in a saturable way. These cells were exposed to different concentrations of cadmium and the synthesis of metallothionein was studied by a cadmium-saturation method. The levels of metallothionein increased with the cadmium concentration in the medium up to 20 microM of metal. Supplementation of the culture medium with 10% bovine milk caused a 25% decrease in the uptake of cadmium with respect to that internalized by the cells maintained in the culture medium alone. However, the uptake of cadmium from the medium supplemented with 10% human milk was similar to that with serum-free medium. beta-Lactoglobulin interacted with cadmium when studied by equilibrium dialysis, showing a stoichiometric binding constant of 5 x 10(4) l/mol. Interaction of lactoferrin with cadmium, however, was negligible. When Caco-2 cells were incubated in culture medium containing lactoferrin, cadmium uptake decreased with respect to that observed incubating the cells in a medium containing beta-lactoglobulin or in the free-protein medium. The inhibitory effect of lactoferrin on the uptake of cadmium might be due to a reduction of the cell surface charge, through its binding to the membrane.

Correlation between the clinical classification of bronchial asthma severity and the methacholine test in children

The purpose of this study was to validate the Methacholine Bronchial Challenge Test in its different degrees and to compare them with the different clinical classifications of bronchial asthma. Fifty-four child asthmatic patients over 6 years of age from the Respiratory Outpatient Clinic at La Union Hospital (Chile) were submitted to the clinical classification of bronchial asthma and later to the Methacholine Bronchial Challenge Test, which classified the children as mildly, moderately or severely hyperreactive to the test. In mildly asthmatic children, the Methacholine Test showed both a high sensitivity (100%) and specificity (92.3%). In moderately asthmatic children, the sensitivity decreased to 84.5%, whilst the specificity was maintained (92.3%). In severely asthmatic children, however, the sensitivity decreased to 53.5%, whilst the specificity increased 97.2%. The latter could be explained as a consequence of the previous exposure of this group of children to either inhaled or oral corticoids. According to our experience, the Methacholine Test is not only useful for the diagnosis of bronchial hyperreactivity in dubious cases, but also for contributing together with the clinical findings to the adequate classification of these patients.

Cell stress and implications of the heat-shock response in skin

Heat-shock proteins (HSPs), or so-called 'stress proteins' may play an important role in cutaneous pathophysiology. HSPs are a group of highly conserved molecules that are expressed by all cells when subjected to heat or other forms of physical or chemical stress. The physiological roles of stress proteins are varied and are important in stress and nonstress conditions. They bind to other cellular proteins and participate in protein folding pathways during stress and also during the synthesis of new polypeptides. HSPs are also essential for thermotolerance and for prevention and repair of damage caused in DNA after ultraviolet exposure. Although HSPs are expressed in the skin in both epidermis and dermis, HSPs may influence many other cellular processes in the inflammatory and immune skin response. Many authors have speculated on a link between HSPs and human skin disease characterized by inflammation and proliferation.

Uptake and passage of beta-lactoglobulin, palmitic acid and retinol across the Caco-2 monolayer

Caco-2 cell line grown on collagen coated polycarbonate membranes in bicameral chambers has been used to study the effect of the binding of palmitic acid or retinol on the uptake and passage of iodinated beta-lactoglobulin and albumin across cell monolayers. The percentage of beta-lactoglobulin transported through the monolayer was higher than that of albumin, about 50% and 30% of the total protein after 24 h of incubation, respectively. In all cases, less than 1% of protein was retained intracellularly. No differences were found in the uptake and transport of beta-lactoglobulin or albumin in the presence or absence of ligands. Furthermore, uptake and passage across Caco-2 monolayer of retinol or palmitic acid added either bound to beta-lactoglobulin or to albumin have been compared. The percentage of retinol found in the lower chamber was about 35% of the total retinol after 24 h of incubation for both proteins. However, the amount of retinol associated to cells was higher when it was added bound to beta-lactoglobulin than to albumin, about 26% and 10%, respectively. This fact suggests that the metabolic processing of retinol by Caco-2 cells is the rate-limiting step for retinol transport. The percentage of palmitic acid that crossed the monolayer was about 7%, remaining approx. 90% in the cells for beta-lactoglobulin and albumin. These data support the hypothesis that palmitic acid internalized by Caco-2 cells is mainly destined to serve the structural and energy needs. These results show evidence of retinol and palmitic uptake by Caco-2 cells when beta-lactoglobulin or albumin are the donors, and indicate that the type of binding protein does not affect the transport of both ligands through Caco-2 monolayer.

Interaction of beta-lactoglobulin with retinol and fatty acids and its role as a possible biological function for this protein: a review

beta-Lactoglobulin is the major whey protein in the milk of ruminants and some nonruminants, such as pigs and horses. Although beta-lactoglobulin was first isolated 60 yr ago, no function has been definitely ascribed to beta-lactoglobulin. Recent x-ray crystallographic studies have advanced knowledge of the structure of beta-lactoglobulin, which is homologous with that of retinol-binding protein and lipocalycins; the function of these proteins seems to be participation in the transport of small hydrophobic substances. By analogy, this protein has been suggested as having a role as a transporter of fatty acids and retinol. This review reassesses the function of beta-lactoglobulin in light of the large amount of information that has accrued in the last few years. In particular, this review concentrates upon studies of the binding of retinol and fatty acids to beta-lactoglobulin, including the binding constants and number of binding sites, the location of the binding sites, and the influence of chemical modifications in the interaction of the protein with both ligands. This study also describes studies of the influence of beta-lactoglobulin on several biological processes that may be relevant to the possible biological role of this protein.

Ten-year follow-up in pediatric patients with allergic bronchial asthma: evaluation of specific immunotherapy

Specific immunotherapy as a treatment for bronchial asthma has been a controversial field. A collaborative study was designed in an attempt to further define the possible contribution of specific immunotherapy in a pediatric population. One hundred and sixty-six patients were treated with immunotherapy and 248 received no immunotherapy. The results were compared during 10 years of follow-up in both groups. There was a significant decrease in the number of acute crisis in the treated group (p < 0.05). However, no differences were seen in the number of hospital admissions or in the quality of life between the treated and untreated groups. The treated group required significantly fewer drugs (p < 0.05). Thus, it is probable that the untreated group shows the same clinical indexes as the treated group due to their increased use of medication. Specific immunotherapy represents an effective treatment that changes the natural course of allergic bronchial asthma in pediatric patients.

Effect of heat treatment and other milk proteins on the interaction of lactoferrin with monocytes

The interaction of lactoferrin from human and bovine milk with the human promonocytic cell line U937 has been studied. Both human and bovine Fe-lactoferrins bound to the cells. Binding of bovine lactoferrin was inhibited by excess bovine lactoferrin but not by human lactoferrin, suggesting that the binding mechanisms for the two proteins are different. Binding of human but not bovine lactoferrin was inhibited by bovine lactoperoxidase, while a 20-fold excess of human IgA inhibited binding of human but not bovine lactoferrin. Human and bovine alpha-lactalbumins, bovine beta-lactoglobulin, and human lysozyme had no effect on binding of lactoferrin from either species. Samples of bovine Fe- and apolactoferrin in capillary tubes were exposed to temperatures of 72 degrees C for 20 s, 85 degrees C for 20 min or 137 degrees C for 8 s. All the heated samples inhibited binding of native Fe- and apolactoferrin, though to a lesser extent than the native proteins. Both heated and native lactoferrins enhanced [3H]thymidine incorporation by U937 cells, except for Fe-lactoferrin heated at 85 degrees C for 20 min, which was inhibitory. These results suggest that heat treatment of lactoferrin under conditions used for industrial processing does not greatly affect its ability to interact with and stimulate monocytic cells, and that other milk proteins in general do not interfere with lactoferrin-monocyte interactions. It may thus be feasible to incorporate biologically active lactoferrin into infant formulas.