Evaluation of sulfate rhizofiltration by Carpobrotus chilensis for treating mining waters

Chile, the world's leading copper producer, generates significant volumes of mining waters, some of which cannot be recirculated into the production process. These mining waters are characterized by elevated sulfate (SO 4 2 - ) concentrations, requiring sustainable management strategies for potential reuse. This study aims to evaluate the rhizofiltration technique using Carpobrotus chilensis for treating mining waters with a high SO 4 2 - concentration. Initially, the mining waters exhibited a pH of 7.97 ± 0.16 and a SO 4 2 - concentration of 2,743 ± 137 mg L-1, while the control water had a pH of 7.88 ± 0.08 and a SO 4 2 - concentration of 775 ± 19.0 mg L-1. The plants were hydroponically cultivated in 40 L containers with mining waters and drinking water as a control. Over an 8-week period, the pH of the mining water decreased to 3.12 ± 0.01, and the SO 4 2 - concentration declined to 2,200 ± 110 mg L-1. Notably, the fresh weight of roots was significantly higher in plants grown in mining water (22.2 ± 6.66 g) compared to those in the control treatment (14.3 ± 4.28 g). However, an undesirable increase in the acidity was observed in the mining waters after rhizofiltration, which was attributed to hydrogen sulfate (HSO4-) and/or root exudates. Despite the unexpected increase in acidity, C. chilensis effectively reduced the concentration of SO 4 2 - in mining waters by 20%. Additionally, the C. chilensis roots accumulated 4.84 ± 1.40% of sulfur (S), a level comparable to thiophore plants. This study provides evidence that this non-aquatic plant can be used in sulfate rhizofiltration.

Demographic and diagnostic markers in new onset pediatric type 1 and type 2 diabetes: differences and overlaps

PURPOSE

Type 1 diabetes (T1D) is the most common type of diabetes in children, but the frequency of type 2 diabetes (T2D) is increasing rapidly. Classification of diabetes is based on a constellation of features that vary by type. We aimed to compare demographic, clinical, and laboratory characteristics at diagnosis of pediatric T1D and T2D.

METHODS

We studied children who visited a large academic hospital in Houston, Texas (USA) with a new diagnosis of T2D (n=753) or T1D (n=758). We compared age, sex, race/ethnicity, presence of obesity, glucose, hemoglobin A1c, islet autoantibody positivity, C-peptide, and presence of diabetic ketoacidosis (DKA) at diabetes diagnosis.

RESULTS

At diagnosis, children with T2D, compared with those with T1D, were older (13.6 years vs. 9.7 years), more likely female (63.2% vs. 47.8%), of racial/ethnic minority (91.1% vs. 42.3%), and obese (90.9% vs. 19.4%) and were less likely to have DKA (7.8% vs. 35.0%) and diabetes autoantibodies (5.5% vs. 95.4%). Children with T2D also had significantly lower glucose, lower hemoglobin A1c and lower C-peptide level (all comparisons, p<0.0001). In multiple logistic regression analysis, older age, racial/ethnic minority, obesity, higher C-peptide, and negative islet autoantibodies were independently associated with T2D (all, p<0.05), while sex, glucose, hemoglobin A1c, and DKA were not (model p<0.0001).

CONCLUSION

There are important demographic, clinical, and laboratory differences between T1D and T2D in children. However, none of the characteristics were unique to either diabetes type, which poses challenges to diabetes classification at diagnosis.

Type 2 diabetes in prepubertal children

OBJECTIVE

Puberty-induced insulin resistance is considered critical in the pathogenesis of type 2 diabetes (T2D) in youth. The development of T2D before puberty suggests distinct risk factors and pathophysiology but, because of its rarity, this has not been well studied. We aimed to describe the clinical characteristics of children with T2D diagnosed before the onset of puberty.

RESEARCH DESIGN AND METHODS

We retrospectively studied all children with autoantibody-negative T2D and available pubertal development assessment seen at our center between July 2016 and July 2019, and compared characteristics of those at Tanner stage I (prepubertal, n = 35) versus those at Tanner II-V of pubertal development (n = 341).

RESULTS

At T2D diagnosis, prepubertal children compared with those at Tanner II-V had higher body mass index z-score (p = 0.003) and higher C-peptide (p = 0.003) (while glucose levels were not significantly different), with differences retaining significance after adjustment for glucose, race/ethnicity and sex. Dyslipidemia occurred in 100% of prepubertal children versus 89.7% of those diagnosed later (p = 0.036). Of the prepubertal children diagnosed under age 10 (n = 13), 69.2% were female, 100% racial/ethnic minority, 100% had obesity with history of dyslipidemia and none with diabetic ketoacidosis.

CONCLUSIONS

T2D, although rarely, can develop before puberty. Children with T2D diagnosed in the prepubertal period have more severe obesity, greater insulin resistance, and more frequent dyslipidemia than older youth. These findings suggest that children with prepubertal T2D are at increased risk for associated morbidity compared with older youth and underscore the significance of interventions to prevent and treat obesity in early childhood.

Islet autoantibody types mark differential clinical characteristics at diagnosis of pediatric type 1 diabetes

BACKGROUND

We aimed to study whether islet autoantibody type marks differential characteristics at the time of type 1 diabetes (T1D) diagnosis.

METHODS

We studied 711 children with newly diagnosed autoimmune T1D. We compared demographic (sex, age, race/ethnicity), clinical (pubertal development, BMI percentile, diabetic ketoacidosis [DKA]) and laboratory (glucose, hemoglobin A1c [HbA1c], C-peptide, tissue transglutaminase antibodies [tTGA], thyroglobulin antibodies, and thyroid peroxidase antibodies [TPOA]) characteristics by presence/absence of autoantibodies to insulin (IAA), GAD65 (GADA), or IA-2/ICA512 (IA-2A). Islet autoantibody titers were evaluated among the children positive for the relevant autoantibody type. We used multivariable analysis to adjust for potential confounders.

RESULTS

IAA+ was statistically associated with younger age (p < 0.0001) and lower HbA1c (p = 0.049) while Tanner stage, GADA status and number of positive islet autoantibodies were not significant in the multivariable model. GADA+ was associated with female sex (OR = 4.0, p = 0.002) and negatively with elevated tTGA titers (>50 U/mL) (OR = 0.21, p = 0.026) but not with age, IAA status, IA-2A status, islet autoantibody number, or thyroid autoimmunity. None of the associations with IA-2A positivity was statistically significant in the multivariable analysis. In multivariable models, IAA titer was significantly associated with younger age (p = 0.006), DKA (p = 0.017) and higher tTGA levels (p = 0.002); GADA titer with female sex (p = 0.028), racial minority (p = 0.046) and TPOA positivity (p = 0.021); and IA-2A titer with older age (p = 0.001) and not being African American (p = 0.024).

CONCLUSIONS

Islet autoantibody type is associated with differential characteristics at diagnosis of pediatric T1D. Longitudinal and mechanistic studies are needed to evaluate T1D endotypes by autoantibody type.

0090 Stage-Specific Sleep Disruption and its Effect on Spatial Navigational Memory

Introduction

The mechanisms by which sleep disruption impact memory may depend on sleep stage, as rapid eye movement (REM) and slow wave sleep (SWS) differ in several significant ways, including degree of neuronal synchrony and frequency of cortical local field potential oscillations. Here we sought to examine the relationship between stage-specific disruption of sleep and its effect on spatial navigational memory.

Methods

9 healthy adult subjects participated in this study which involved 3 in-lab polysomnograms (normal, REM-disruption, and SWS-disruption) accompanied by pre- and post-sleep functional neuroimaging of brain during a spatial navigational memory task. Graded auditory stimuli consisting of 0.5 second bursts of high-frequency tones (300-3000Hz) were used to disrupt sleep (REM/SWS) in real time. Primary metrics to ascertain the effect of these auditory tones on sleep were time in sleep stage (REM/SWS) as a % of total sleep time (TST), bout length. The primary metric for spatial navigational memory was %change in overnight completion time on a first-person-experience 3D maze task.

Results

Sleep macrostructure was normal during the normal night (TST:379.9±56.6 min; SWS:19.5±7.6%; REM:19.4±5.3%; mean±std). Stage-specific disruption of sleep was achieved using auditory tones during a) SWS-disruption condition (TST:388.9±47.4 mins; SWS:6.6±4.8%; REM:18.7±5.2%) and b) REM-disruption condition (TST:365.3±69.8 mins; SWS:17.1±7.7%; REM:12.1±6.6%). SWS-disruption reduced mean bout length of SWS as compared to no disruption (1.3±0.8 mins vs. 10.3±8.2 mins; p&lt;0.01) and REM-disruption reduced mean bout length of REM as compared to no disruption (2.2±1.7 vs. 10.6±5.2 mins; p&lt;0.01). When sleep was not disrupted, subjects achieved overnight improvements in performance (25.3±17%) which remained unchanged during REM-disruption (18.8±29.6%, p=0.5) and during SWS-disruption (38.8±24.4%; p=0.2). Morning psychomotor vigilance was also unaffected by condition.

Conclusion

Stage specific disruption of sleep can be achieved using graded auditory tones. While performance on a virtual 3D maze remain unchanged with stage specific sleep disruption, lower sample size may have limited our ability to detect the change. Activation patterns from functional neuroimaging that were acquired during the spatial navigation task may elucidate the interaction between stage-specific sleep disruption and performance.

Support

NIH R21AG059179

0144 Relationship Between Sleep EEG K-Complex Slow Wave Coupling and Next-Day Thalamic Activity During Psychomotor Vigilance Test in Obstructive Sleep Apnea

Introduction

There is large inter-individual variability in the relationship between obstructive sleep apnea (OSA) severity and lapses in vigilance as measured using psychomotor vigilance test (PVT). We have previously shown that overnight sleep EEG K-complex slow wave coupling (∆SWAK) exhibits a dose-responsive relationship with next-day lapses in vigilance in OSA on and off treatment. We hypothesized that a variable thalamic dysfunction in OSA explains difference in lapses in vigilance and alterations in ∆SWAK across individuals.

Methods

Five newly diagnosed severe OSA subjects (mean apnea-hypopnea index [AHI4%=57.1±22.8/hr.]) with excessive daytime sleepiness (Epworth Sleepiness Scale=11±3.4) underwent nocturnal polysomnography followed by PVT testing within a 3T SKYRA MRI scanner. The PVT task inside the scanner (PVT-fMRI) was adapted to match the gold standard PVT-192 device. Each fMRI scanning session consisted of 2 10-min PVT runs interleaved with 2 control conditions wherein the subject pressed the response button at random intervals absent of a visual stimulus. fMRI data was analyzed in 2-step procedure (individual time-series followed by group analysis) using Analysis of Functional Neuroimages (AFNI) software package. To estimate thalamic activity during PVT-fMRI, parameter estimates of the %change in blood-oxygen-level-dependent (BOLD) signal using the contrast PVT-Control were used as the primary metric. The region of interest was limited to the bilateral thalamus using the Eickhoff-Zilles macro labels from the MNI N27 template.

Results

In a preliminary test, PVT performance for the subjects inside the scanner was not significantly different from that outside the scanner (PVTLapsesfMRI=7.3±2.1 vs. PVTLapsesPVT192=6.4±3.6 mean±std; PVTLapses=reaction time &gt; 500 ms.). Within subjects, a trend toward lower thalamic recruitment was observed during PVT-fMRI (-0.17±0.2%; p=0.1). Further, lower thalamic activity during PVT-fMRI also showed a trend to lower overnight ∆SWAK (mean -1.2±1.4) values (r = 0.61, p = 0.17).

Conclusion

In severe OSA subjects with excessive daytime sleepiness, we observed a trend to reduced thalamic activity during daytime PVT. Overnight EEG K-complex slow wave coupling showed a similar trend with next-day thalamic activity during PVT, however the small sample size may have limited our ability to detect this association with statistical significance.

Support

AASM Foundation 199-FP-18; NIH K24HL109156

Availability of copper in mine tailings with humic substance addition and uptake by Atriplex halimus

The chemical characteristics of mine tailings, organic amendments (doses), and plants are the critical factors that must be evaluated and monitored to ensure the sustainability of phytostabilization. The aim of this study was to evaluate the mobility of copper (Cu) in mine tailings (MT) of the Zone Central of Chile to which commercial humic substances were added, examining their effect on the uptake of Atriplex halimus. Two commercial humic substances (HS1 and HS2) extracted from leonardite (highly oxidized lignite), of different pH and total organic carbon, were evaluated by adsorption curve for Cu. In columns, soluble Cu, pH, and electrical conductivity in leachates were evaluated for MT, MT + HS1, and MT + HS2, and HS1 and HS2 in doses of 120 mg kg^-1. In pot assay, seeds were germinated directly in MT and cultivated for 140 days with the addition of HS2 in 120 and 240 mg kg^-1. Mine tailing presents high concentration of Cu (2016 ± 223 mg kg^-1, pH 6.3 ± 0.1). The results of sequential extraction indicate that Cu is associated with the sulfide fraction of low risk of mobility. The amount of Cu sorbed by HS1 was higher than that sorbed by HS2, and both humic substances showing better fit to the Freundlich than Langmuir model. Lixiviation of Cu was significantly lower in MT + HS1 (0.166 ± 0.043 mg kg^-1) and MT + HS2 (0.157 ± 0.018 mg kg^-1) than in MT (0.251 ± 0.052 mg kg^-1). Copper concentration in plants reached 185.8 ± 37.8 mg kg^-1 in the roots and 32.6 ± 7.4 mg kg^-1 in the aerial parts cultivated in MT without effect of the humic substance addition in Cu uptake nor growth. Copper concentrations in the aerial parts were adjusted to sufficient or normal levels in plant. A good management of mine tailings through phytostabilization could consider an adequate mixture of humic substances (to avoid leaching of metals) and an organic amendment that provides essential nutrients and increases biomass generation.

Abstract 331: My Unlimited Health Potential: 6 Month Effect of Participation in a Worksite Lifestyle Intervention Program on Significant Weight Loss and Eligibility Criteria for Bariatric Surgery Among High Risk Individuals

BACKGROUND: Current recommendations support bariatric surgery among the morbidly obese as an option to mitigate future risk of cardiovascular disease, diabetes and hypertension. To date, there is little evidence on the effect of extensive lifestyle interventions among those high-risk individuals in reducing the need for such procedures.

METHODS: The purpose of the present study is to examine the efficacy of an intensive lifestyle workplace intervention on significant body weight and cardiovascular disease risk factors across the spectrum of obesity. Changes in BMI are being measured from baseline to 6 months follow up, along with corresponding improvements in cardio-metabolic risk. In addition, the decrease in participants meeting criteria for bariatric surgery over the study period is examined. Bariatric surgery criteria were defined as BMI≥40 or BMI between 35 and 40 and at least one of the following co-morbidities: diabetes, hypertension, or high cholesterol. Short term results (at 9-12 weeks follow-up) of this study are being presented at AHA 2014 in March.

RESULTS: The study population consisted of 152 individuals (49±10 years, 78% female) with BMI≥27 at baseline and complete data at 6 month follow-up. A total of 71 (47%) participants lost at least 10 % of their body weight. Additionally, 37% dropped an entire BMI category. Of note, 39%(16 of 41) who were classified as BMI>40 were in BMI 35-39 at follow-up, respectively 44%(14 of 32) of individuals in the BMI category 35-39 successfully moved to the BMI category 30-34 at 6 months follow-up. Forty-five participants (35% of total) initially met criteria for bariatric surgery. At 6 months of follow-up 40% (18 of 45, p<0.001) of these candidates no longer needed bariatric surgery.

CONCLUSIONS: Worksites can be effective for achieving clinically important reductions in body weight and diminish the potential need for procedures among a small proportion of morbidly obese individuals. Many lifestyle interventions succeed in achieving short term reductions but are unable to sustain them over longer periods. Our program shows promising results at 6 months and continued follow up will allow us to determine whether workplace wellness interventions similar to ours are a viable and lasting alternative to bariatric surgery.

Abstract 327: Six months follow-up of “My Unlimited Potential”, A 12-week Worksite, Multi-Component, Lifestyle Intervention for Improving Cardiometabolic Health in High Risk Persons

Background: With about 59% of the entire US population currently in the work force, the American Heart Association has emphasized worksite-based interventions to improve cardiovascular health among the working population. The primary aim of this study was to assess effectiveness of an ongoing multi-component, lifestyle improvement program (My Unlimited Potential [MyUP]) extending into 6 months, among employees of Baptist Health South Florida (BHSF), a large not-for-profit health care system.

Methods: BHSF employees with 2 or more Cardiometabolic risk factors, such as total cholesterol ≥ 200 mg/dl, systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg, hemoglobin A1C ≥ 6.5%, and body mass index (BMI) ≥ 30 were considered for the study. Behavioral interventions were focused on dietary and physical activity modifications.

Results: Overall 202 (48±10 years, 78% females) employees who enrolled in the MyUP wellness program. The retention of subjects was high with 89% (n=181) at 12 weeks and 80% (n=162) at 6 months. The table and figure below demonstrate the baseline, 12 week and 6 months averages in anthropometric and laboratory profile in participants. Comparing follow-up from 3 months to that at 6 months, clinically meaningful improvement in endpoints were especially noted for BMI, BP, HDL targets, and reducing burden of systemic inflammation (figure).

Conclusion: These findings suggest that an intensive behavioral modification intervention program, delivered to employees in a health care setting, results in both significant short and intermediate term benefit in weight reduction, improved blood pressure control and hbA1c, and concomitantly improves cardio-metabolic risk profile. Further follow-up is in progress to ascertain whether these benefits are sustainable over longer periods.

Comparison of methods for teaching developmental milestones to pediatric residents

BACKGROUND

Interactive media are effective tools in teaching and allow for self-directed study, which develops skills for life-long learning among health professionals. With this type of study, the learner can review material at his/her own pace and target areas that require emphasis. Pediatric residents require an accurate understanding of developmental milestones in children of various ages and their normal variations. The best representation of developmental milestones requires video recordings of children demonstrating appropriate skills. However, such recordings are not always available, so printed materials are most often used. In this realm, a computer-based interactive learning tool using animated cartoons gives flexibility for presentation using drawings. We compared pediatric residents' knowledge of developmental milestones in neonates to 5-year-olds before and after study with either an interactive DVD or paper-based materials.

METHODS

A team of physicians and educational specialists in Texas Tech University Health Sciences Center produced an interactive DVD containing animated cartoons and questions. Residents were divided into an intervention group that used the DVD and a control group that used traditional paper-based materials. Each group's improvement [or increase] in knowledge was measured.

RESULTS

Compared with the 17 residents in the control group, the 37 in the intervention group tended to acquire more knowledge about developmental milestones. The mean scores at T1, T2, and T3 doubled from the initial scores in the intervention group, while no difference was observed in the control group.

CONCLUSION

An interactive educational DVD can be an effective supplement to improve residents' knowledge of developmental milestones.

Injection of botulinum toxin A for the treatment of dysfunction of the upper esophageal sphincter

OBJECTIVE

The objective was to evaluate changes in swallow safety and dietary status after the transcutaneous injection of botulinum toxin A into the upper esophageal sphincter in a series of outpatients with dysphagia.

STUDY DESIGN

This was an experimental, prospective, nonrandomized study.

METHODS

Patients who were at risk for aspiration and who had an unsuccessful trial of swallowing therapy were admitted to the study. All patients showed significant pooling of fluids in the postcricoid region. All patients were treated in the office; none had previous esophageal dilatation. The upper border of the cricoid cartilage was identified using standard electromyogram procedures and 100 U of botulinum toxin (Botox A) were injected. Outcomes were assessed using the penetration-aspiration scale, patients' short-term and long-term subjective impressions of their ability to swallow, and change in dietary status.

RESULTS

Thirteen patients underwent an instrumental evaluation of swallowing function at approximately 6 months after treatment to corroborate the self-reported changes in swallowing. Of the 13 patients, 12 showed an overall improvement in their ability to take an oral diet safely as evidenced by the penetration-aspiration scale. Of the 12 patients who were on a non-oral or nearly non-oral diet, 9 resumed a normal oral diet. The remaining 3 were on an oral diet supplemented by percutaneous endoscopic gastrostomy feeding. One patient remained on a non-oral diet.

CONCLUSIONS

Injection of Botox A in the office with no additional treatments resulted in a long-term increase in swallow safety, a reduction of penetration and/or aspiration, and a reduced need for non-oral feeding. Injection of Botox A in the office should be considered when there is failure of the cricopharyngeus muscle to relax after the swallow, significant pooling in the cricopharyngeal region, and a risk for penetration and aspiration.

Liver abscess caused by Ascaris lumbricoides: case report

A case is reported of a woman who lived in a rural area with a chronic illness that consisted of weight loss and abdominal pain in the epigastrium and upper right quadrant. The initial diagnosis was a mass in the liver, which was later, demonstrated, both by direct and histological examination, to be an abscess caused by Ascaris lumbricoides. Eggs of Ascaris lumbricoides and abundant Charcot-Leyden Crystals were found.

Determination of tetracycline and its major degradation products by liquid chromatography with fluorescence detection

A liquid chromatographic method of tetracycline and its major degradation products on a C8-reversed phase column with acidic mobile phase and fluorescence detection is described. The quantification limit, measured as the amount of sample that gave a signal ten times the peak-to-peak noise of the baseline, was: 0.25 ng for tetracycline (TC) and epitetracycline (ETC), 25 ng for and 4-epianhydrotetracycline (EATC) and 50 ng for anhydrotetracycline (ATC) of injected standard. By means of this liquid chromatography (LC) assay TC, ETC, EATC and ATC as main degradation products of tetracycline, can be separated and determined with good sensitivity and specificity within 15 min.

Plant regeneration from encapsulated somatic embryos of Carica papaya L

Carica papaya L. (papaya) single somatic embryos (2.0 mm diameter) produced in a high-frequency liquid production system were encapsulated in two different synthetic encapsulation compounds. The frequency of regeneration from encapsulated embryos was significantly affected by (1) the concentration of sodium alginate, (2) the presence or absence of nutrient salts in the capsule, and (3) the duration of exposure to calcium chloride. A 2.5% sodium alginate concentration in a half-strength MS salts base resulted in significantly higher germination frequencies than other treatments. A relatively short (10 min) exposure to CaCl₂ provided uniform encapsulation of embryos and the highest frequencies of successful germination (77.5%). Germinated artificial seeds produced normal plantlets.

[Medical certification of deaths by trauma in the Chilean health services]

BACKGROUND

Trauma in the third cause of death in Chile and the most important among youngsters.

AIM

To analyze the certification of deaths by trauma, studying those deaths in which it is not known if they were accidental or self inflicted.

MATERIAL AND METHODS

Deaths certified as caused by trauma, poisoning or violence during the period 1992-1994 are analyzed. Those in which their accidental or self inflicted nature was ignored were specially considered.

RESULTS

During the study period, 26,886 f 225,796 deaths were certified as caused by trauma, poisoning or violence. In 41.7% of these deaths, no defined cause (accidental or self inflicted) was reported) was reported. In the Metropolitan region 65.3% of deaths by trauma were not defined. Ninety seven percent of certificates in this area were extended by pathologists or coroners. In all health services, there was a positive correlation between the percentage of ill defined deaths by trauma and the percentage of certifications by pathologists or coroners.

CONCLUSIONS

The deficiency in certification of deaths by trauma is possibly due to administrative causes and precludes the study of deaths caused by accidents, violence or suicide in Chile and its comparison with other countries. An effort should be done to solve this problem.

[Hereditary spherocytosis. Course and value of subtotal splenectomy]

BACKGROUND

Effectiveness of subtotal splenectomy, a procedure recently advocated as an alternative treatment to total splenectomy for patients with hereditary spherocytosis (HS), has been evaluated.

METHODS AND PATIENTS

Eighty-eight patients (74 children) with HS were included in this series. Clinical presentations ranged from asymptomatic cases to severe transfusion-dependent forms. Stunting of growth occurred in four cases; chronic fatigue was observed in 30 cases and cholelithiasis in 21 cases. Among the red cell indices measured by laser light scattering on Technicon H2, the most reliable for diagnosis was the abnormal percentage of hyperdense red cells (98% of HS patients). Osmotic gradient ektacytometry, used to measure membrane deformability and impairment of maximal deformability due to a reduction of erythrocyte surface, always showed the characteristic curves of HS.

RESULTS

Subtotal splenectomy was performed in 24 patients leading to a remnant spleen of about 25% of normal for age volume. This decreased the hemolytic rate while adequately sustaining the phagocytic function of the spleen (assessed by percentage of "pitted erythrocytes" and technetium 99n scans of the remnant). However, the observed reduction in hemolytic rate was not as extensive as that observed after total splenectomy (six cases) and subtotal splenectomy did not entirely prevent risk of cholethiasis (three cases).

CONCLUSION

This subtotal splenectomy (+/-cholecystectomy) has to be particularly considered for children with transfusion-dependent forms of HS, in order to obtain the benefits of increased hemoglobin levels without the pending risk throughout life of overwhelming post-splenectomy infections.

Direct somatic embryogenesis fromBegonia gracilis explants

Direct somatic embryogenesis ofBegonia gracilis was achieved from microcultured laminar segments and petioles on Murashige and Skoog medium with 0.5 mg 1^-1 kinetin and 2% coconut water. Somatic embryos were obtained with greater frequency from petiole explants than from leaf blade sections. Under red light (45 μmol m^-2 s^-1), approximately 80% of the petiole explants successfully produced somatic embryos but only 30% of the leaf blade sections responded. However, somatic embryos were significantly more abundant on responding lamina explants (60-70 embryos/leaf section) than on petioles (40-50 embryos/petiole). These trends were similar for explants kept in the dark, but overall production was lower. Somatic embryos were produced more quickly (5 weeks) from petioles than from lamina explants (8 weeks). The somatic embryos germinated to produce plantlets and subsequently shoot cultures with the same appearance as the parental clone.

Direct somatic embryogenesis fromBegonia gracilis explants

Direct somatic embryogenesis ofBegonia gracilis was achieved from microcultured laminar segments and petioles on Murashige and Skoog medium with 0.5 mg 1^-1 kinetin and 2% coconut water. Somatic embryos were obtained with greater frequency from petiole explants than from leaf blade sections. Under red light (45 μmol m^-2 s^-1), approximately 80% of the petiole explants successfully produced somatic embryos but only 30% of the leaf blade sections responded. However, somatic embryos were significantly more abundant on responding lamina explants (60-70 embryos/leaf section) than on petioles (40-50 embryos/petiole). These trends were similar for explants kept in the dark, but overall production was lower. Somatic embryos were produced more quickly (5 weeks) from petioles than from lamina explants (8 weeks). The somatic embryos germinated to produce plantlets and subsequently shoot cultures with the same appearance as the parental clone.

Regulation of matrix metalloproteinases following cellular transformation

During progression towards malignancy, many tumor cells display changes in their repertoire of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs). The recent finding that many members of the MMPs are regulated by protooncogenes may explain the frequent observation of changes in MMP gene expression during progression of many tumor types. While studies involving enzymatic assays of MMPs are usually confined to one or a few MMPs, reverse transcription-PCR (RT-PCR) permitted the analysis of seven members of the MMP family and two members of the TIMP family in several normal and transformed cell lines. RT-PCR permitted us to confirm the observation that MMP-9 is activated following transformation and also to observe the previously unreported activation of MMP-7 in SV40-transformed cells. It has previously been found that MMP-1, -2, -3, -8, and -9 are upregulated by phorbol esters; we have found that MMP-10 is also upregulated by phorbol esters. The phorbol ester upregulation of MMP-1, -3, and -10 was found to be abolished in cells transformed by SV40 virus. Several studies have shown that MMP-1 is upregulated by an integrin-mediated signal transduction pathway. This study demonstrates that MMP-3 and MMP-10 are also regulated by integrin-mediated signal transduction and that upregulation by this pathway is abolished following SV40 transformation. In summary, the more global view of MMP expression afforded by RT-PCR indicates that MMP-1, -3, and -10 are regulated by both integrin-mediated signal transduction and phorbol esters. While fibroblasts and transformed bone cells express several members of the MMP gene family, several other cell types do not express MMPs.

Transplantation of human fetal retinal pigment epithelium rescues photoreceptor cells from degeneration in the Royal College of Surgeons rat retina

PURPOSE

The Royal College of Surgeons (RCS) rat suffers from a well-characterized, early-onset, and relentless form of photoreceptor cell degeneration. It has been shown that allografts of retinal pigment epithelial cells from normal perinatal rats have rescue effects in this condition. In preparation for human application, the authors determined whether human fetal retinal pigment epithelium (RPE) grafts have a photoreceptor rescue effect in RCS dystrophic rat retinas.

METHODS

Sheets of RPE from human fetal eyes (10 to 16 weeks gestational age) were isolated according to the authors' recently described method. Fragments of the RPE sheets were transplanted to the subretinal space within the superior hemisphere. Transplants were performed within the superior equatorial region of five dystrophic RCS rats, one eye per animal. A similar volume of vehicle was injected into the subretinal space of five age-matched control rats, again one eye per rat. All rats were immunosuppressed with daily injections of cyclosporine. Using light microscopy, photoreceptor cell nuclear profiles of superior equatorial (SE) and inferior equatorial (IE) regions of transplanted and sham-injected control animals were counted.

RESULTS

Four weeks after transplantation, a dramatic rescue effect was observed. Microscopically, presumptive donor RPE cells were seen as single pigmented cells and as cell clusters in the subretinal space. An outer nuclear layer three to four profiles thick was present in the area of the RPE transplant but was nearly absent in the rest of the retina, as well as in the retinas of control rats. The number of photoreceptor nuclear profiles per 100 microns was 34.7 +/- 2.2 (mean +/- SEM) in the SE region of transplanted rats and 3.5 +/- 1.4 in the same region of sham-injected rats. There were 3.0 +/- 1.0 photoreceptor nuclear profiles in the IE region of transplanted rats and 3.5 +/- 1.2 in the IE region of sham-injected eyes. No evidence of graft rejection was seen.

CONCLUSIONS

This study provides the first indication that transplanted human fetal RPE cells are able to rescue photoreceptor cells in a model of hereditary retinal degeneration.

Retinal ganglion cell survival is promoted by genetically modified astrocytes designed to secrete brain-derived neurotrophic factor (BDNF)

Genetically engineered cells carrying genes for neurotrophic factors have potential application for treatment of neurodegenerative diseases and injuries to the nervous system. Brain-derived neurotrophic factor (BDNF) promotes the survival of specific neurons, including retinal ganglion cells (RGC). To determine whether genetically engineered astrocytes might be used for delivering bioactive BDNF, we infected primary type 1 rat astrocytes with a retrovirus harboring a human prepro-BDNF cDNA and assayed the medium conditioned by these astrocytes for effects on survival of rat RGCs in vitro. High levels of BDNF mRNA were expressed by infected astrocytes, but not by control astrocytes as determined by RNase protection assay using a BDNF specific probe. To test for secretion of bioactive BDNF from the transgenic astrocytes, embryonic day 17 rat retinas were dissociated and grown in medium conditioned (CM) for 24 h by astrocytes infected with a replication deficient retrovirus carrying BDNF, NGF, or alkaline phosphatase (AP) cDNA. After 3 days, the number of Thy-1 immunoreactive RGCs was counted. BDNF astrocyte CM significantly enhanced RGC survival by 15-fold compared to the AP control. NGF astrocyte CM had no significant effect. The rate of BDNF secretion was estimated at 83-166 pg/10(5) cells/h. This study demonstrates that astrocytes can be genetically engineered to synthesize and secrete bioactive BDNF. These techniques may be applicable to rescuing neurons from degenerative processes and also for enhancing their survival following transplantation.

[Breast neoplasm: health care and life quality in premature mortality]

Eight epidemiological indicators and eleven variables pertaining to the chilean population are analyzed regarding their possible relation to cancer of the breast. The observed and expected mortality rates are discussed. Multiple regression models are employed to evaluate their effect on health. The rate is 2.9 per 100,000 women in the age 30-34 years age group and 46.7 por 100,000 women in the 60-64 years age group. A one year increase in age elevates risk of cancer by 1.4 average. There is a great variation among the different regions of the country particularly in the younger age.

[Years of life lost according to causes of death in Chile: 1981-1983]

An estimated total of 811,037 years of life were lost for persons between 28 days and 64 years of age in Chile from 1981 to 1983. 63% correspond to males. Main causes of death accounting for these figures include non accidental violent death (15.6%), accidental death (13.4%), pneumonia and influenza (9.9%), tumors (7.5%) and cirrhosis of the liver (5.6%). Almost 50% of the loss occurred in the 28 day to 11 month and the 25 to 44 year age groups. Regional variation, from a minimum of 5895 years of life lost for 100,000 persons in Arica to 9,640 in Bio-Bio.

[Evolution of mortality by causes (1960-1982)]

Mortality from all causes has decreased in Chile by 50% from 1960 to 1982. Median age of death increased from 28 to 66 years. Reduction in mortality rate was greater for those under 15 years of age, mostly due to a decrease in mortality from digestive, respiratory, infectious and neonatal diseases. In contrast, only 16% reduction was observed in mortality for the 65 and over age group. This may be due to a relative increase in mortality from cardiovascular diseases in the older age group. Multiple factors are involved in the improvement of these health indexes, such as changes in socio-economic conditions, health delivery policies and demographic change of the population.

[Mortality differences according to sex: causes and associated factors]

A higher general mortality was observed for males between 1981 and 1983, in relation to trauma, cardiovascular and digestive diseases. This may indicate a poorer attitude towards health care in males. The difference is more marked in the younger population and in the old age group due to different causes in each case. Geographic and lifestyle patterns also contribute to explain differences in mortality. Multiple regression analysis suggests that socioeconomic factors explain different mortality rates among geographical regions, with a lesser contribution from differences in the quality of local health care delivery.

Hypernatremic diarrheal dehydration treated with oral glucose-electrolyte solution containing 90 or 75 mEq/L of sodium

Of 33 infants with hypernatremic dehydration (serum Na+ of greater than or equal to 150 mEq/L) 7 were excluded, 6 because severe alteration of the level of consciousness or shock precluded oral rehydration and 1 because he was given glucose-electrolyte solution plus water. We studied the remaining 27 infants. Twenty (group A) were treated with the World Health Organization-recommended oral rehydration solution (90 mEq/L Na+) and seven (group B) were treated with Pedialyte-RS (Abbott Laboratories Ltd.; 75 mEq/L Na+). The rehydrating solutions were administered in a volume equivalent to twice the clinically estimated fluid deficit. Initial serum sodium was 156.7 +/- 0.9 mEq/L for group A and 155.8 +/- 1.8 mEq/L for group B (mean +/- SEM). The mean time to achieve rehydration was 14.3 and 16.6 h for groups A and B, respectively. Twenty-four hours after commencing oral rehydration, serum Na+ had decreased to 144.8 +/- 1.8 mEq/L for group A and 144.5 +/- 0.9 mEq/L for group B. In two patients in group A, the serum Na+, which, had not decreased to less than 150 mEq/L at 24 h, did so at 48 h. Only in one case (group A) did the serum Na+ increase. This patient had high stool output and failed to become rehydrated after 24 h of unsuccessful oral rehydration. None of the patients had seizures or persistent CNS dysfunction. We conclude that the slow administration of oral rehydration solutions containing either 90 or 75 mEq/L Na+ is a safe and effective treatment of hypernatremic dehydration.

Efficacy comparison of oral rehydration solutions containing either 90 or 75 millimoles of sodium per liter

In a randomized trial, 62 infants 2 to 35 months of age with dehydration due to acute watery diarrhea were allocated to one of two groups: group A received solution A (World Health Organization-recommended oral rehydration solution), which contained (mmol/L): Na+ 90, K+ 20, Cl- 80, citrate3- 10, and glucose 110; group B received solution B (Pedialyte RS; Abbott Laboratories, North Chicago), which contained (in mmol/L): Na+ 75, K+ 20, Cl- 65, citrate3- 10, and glucose 139. Oral therapy was given until clinical signs of hydration status were normal. During the 48-hour trial, the following laboratory data were collected: blood gases, serum electrolytes, glucose, urea, and creatinine values and sodium and potassium concentrations in stool and urine; serial weights and clinical signs were also reported. Six of the 62 infants, three in each group, required intravenous fluids because of high stool output. Results of clinical outcome and normalization of altered serum electrolyte values were similar in both groups. During the 48-hour trial, eight patients in group A and four in group B had mild, asymptomatic hypernatremia. Pedialyte RS was found to be a safe glucose/electrolyte solution for oral rehydration therapy.

The effect of burn wound size on ureagenesis and nitrogen balance

Hypermetabolic burn patients are frequently in negative nitrogen balance despite provision of estimated caloric needs. We studied 18 thermally injured adult patients in order to evaluate the relationship of burn wound size to urea production and nitrogen balance. We selected data from 147 patient-days when the patients received 100 +/- 25% of their estimated caloric needs. Three significantly different burn size groups (by body surface area [BSA]) were identified by calculation of the catabolic index (CI): group 1, 0-10% BSA (CI = -0.1); group 2, 11-30% BSA (CI = 6.4); and group 3,31-60% BSA (CI = 10.5). The urine urea nitrogen (UUN) for groups 1,2, and 3 was 11.1, 18.9, and 25.3 gm/day, and nitrogen balance was 1.0, -3.9, and -5.8 gm/day, respectively. When nitrogen was given in a calorie:nitrogen ratio of 150:1, only those patients in group I were able to achieve positive balance. We conclude that large burn wounds are associated with increased ureagenesis and impaired nitrogen retention. The protein intake, at the customary calorie:nitrogen ratio of 150:1, may not provide adequate nitrogen to achieve equilibrium, even when energy demands have been met, in patients with burn wounds greater than 10% BSA.