Theoretical investigation of transcranial alternating current stimulation using laminar model

Transcranial alternating current stimulation (tACs) has been gaining an increased interest in the last few years due to its capacity to modulate non-invasively high-order cortical processes, such as decision-making, language and sensory perception. Nevertheless, the underlying mechanisms of activation of this brain stimulation technique are still poorly understood. Herein, we use a finite element modelling (FEM) technique to investigate the penetration and focality of tACs in comparison to a time invariant (DC) stimulation. We show that AC stimulations generate cerebral fields that are an order of magnitude larger in the radial direction, approximately 5 times larger in the tangential direction and more focused than DC stimulations. We argue that the basis for this effect is the reduced scalp's conductivity, which minimizes the surface shunting of the stimulating currents. The outcomes of this study may help tACs users to design better protocols and interpret experimental results.

A comparative study between fluoroscopic and endoscopic guidance in palliative esophageal stent placement

Self-expanding metallic stents (SEMS) are the treatment of choice for incurable obstructive malignant esophageal strictures. Although the placement of SEMS is usually performed with fluoroscopic control (FC), recently several authors have shown the feasibility of placing SEMS under endoscopic control alone (EC). However, studies comparing the two techniques are lacking. The objective of this study was to compare the feasibility and safety of SEMS insertion under fluoroscopic control and endoscopic control. The study was performed through the retrospective analysis of patients who underwent SEMS insertion for malignant dysphagia between January 2005 and January 2010. Data concerning early and late complications and survival were retrieved. Early complications were defined as pain, vomiting, bleeding, malposition/migration, perforation, and/or dysphagia occurring until 30 days of SEMS insertion; and late complications as tumor ingrowth and overgrowth, migration, hemorrhage, fistulae, food impaction, and/or esophagitis occurring after 30 days. We placed 126 SEMS of which 87% for esophageal stricture, 8% for esophagus-respiratory fistula, and 5% for extrinsic compression. The mean age of the patients was 62 years, and 93 were male. SEMS insertion was performed with FC in 66 patients and EC in 60. Early complications occurred in 34 patients (52%) in the FC group and 28 (47%) in the EC group (P=0.71), including: pain in 22 patients of the FC group and 15 of the EC group (P=0.31); vomiting in 15 of the FC group and nine of the EC group (P=0.27); malposition/migration in three of the FC group and four of the EC group (P=0.60); hemorrhage in one of the FC group and two of the EC group (P=0.27); and dysphagia in two of the FC group and three of the EC group (P=0.57). Late complications occurred in 20 patients (30%) in the FC group and 22 (37%) in the EC group (P=0.44), including: tumor in/overgrowth in 13 patients of the FC group and 10 of the EC group (P=0.66); prostheses migration in five of the FC group and eight of the EC group (P=0.28); hemorrhage in two of the FC group and two of the EC group (P=0.54); appearance of esophageal fistulae in seven of the FC group and four of the EC group (P=0.43); food impaction in nine of the FC group and eight of the EC group (P=0.96); esophagitis in 12 of the FC group and 15 of the EC group (P=0.35). Median survival was 107 days (95% confidence interval [CI]=6-369 days) with no difference between the two groups. There were no statistical significant differences in the incidence of complications and in survival between patients undergoing SEMS placement under fluoroscopic control or endoscopic control.

Liver abscess of the caudate lobe due to Staphylococcus aureus in an ulcerative colitis patient: First case report

Liver abscesses are very rare complications of ulcerative colitis, with only nine cases described in the literature, to our knowledge. We report a case where a recurrence of liver abscess occurred in an ulcerative colitis patient, in two different hepatic lobes, which has not been previously described. The recurrence was in the caudate lobe having the cultures yielded Staphylococcus aureus. This is also the first case report of liver abscess in this location and caused by this microorganism in an ulcerative colitis patient. A review of the literature concerning liver abscesses involving ulcerative colitis patients is also provided.

Permanent genetic resources added to Molecular Ecology Resources Database 1 December 2010-31 January 2011

This article documents the addition of 238 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alytes dickhilleni, Arapaima gigas, Austropotamobius italicus, Blumeria graminis f. sp. tritici, Cobitis lutheri, Dendroctonus ponderosae, Glossina morsitans morsitans, Haplophilus subterraneus, Kirengeshoma palmata, Lysimachia japonica, Macrolophus pygmaeus, Microtus cabrerae, Mytilus galloprovincialis, Pallisentis (Neosentis) celatus, Pulmonaria officinalis, Salminus franciscanus, Thais chocolata and Zootoca vivipara. These loci were cross-tested on the following species: Acanthina monodon, Alytes cisternasii, Alytes maurus, Alytes muletensis, Alytes obstetricans almogavarii, Alytes obstetricans boscai, Alytes obstetricans obstetricans, Alytes obstetricans pertinax, Cambarellus montezumae, Cambarellus zempoalensis, Chorus giganteus, Cobitis tetralineata, Glossina fuscipes fuscipes, Glossina pallidipes, Lysimachia japonica var. japonica, Lysimachia japonica var. minutissima, Orconectes virilis, Pacifastacus leniusculus, Procambarus clarkii, Salminus brasiliensis and Salminus hilarii.

Dysplasia surveillance in an ulcerative colitis patient: successful detection with narrow band imaging and magnification

One of the contemporary challenges gastroenterologists face is cancer screening and surveillance in long-term colitis patients. The search for a consensually practical and effective method to routinely detect dysplastic mucosa persists. In recent years, publications demonstrating the applicability of narrow band imaging (NBI) in this setting have sparked further research. We present a case report where NBI with magnification played a fundamental role in the detection of dysplasia in an ulcerative colitis patient. This case reinforces the potential widespread applicability of NBI as a surveillance tool in distinguishing dysplastic from nondysplastic colorectal lesions in ulcerative colitis.

Colon cancer after infliximab therapy for Crohn's disease

Infliximab is an effective agent in the treatment of patients with Crohn's disease. Therapy with infliximab is generally well tolerated but there are concerns about its effects on the incidence of cancer. This case report refers to a 47-year-old patient with long-standing Crohn's disease, without a family history of colorectal cancer, who had a previous diagnosis of low-grade dysplasia that was not confirmed in subsequent studies, and was diagnosed with adenocarcinoma of the colon with peritoneal invasion after the fourth infusion of infliximab.

Cardiolipin, a key component to mimic the E. coli bacterial membrane in model systems revealed by dynamic light scattering and steady-state fluorescence anisotropy

The phase transition temperatures of several lipidic systems were determined using two different techniques: dynamic light scattering (DLS) and steady-state fluorescence anisotropy, using two fluorescent probes that report different membrane regions (TMA-DPH and DPH). Atomic force microscopy (AFM) was used as a complementary technique to characterize different lipid model systems under study. The systems were chosen due to the increased interest in bacterial membrane studies due to the problem of antibiotic drug resistance. The simpler models studied comprised of mixtures of POPE and POPG lipids, which form a commonly used model system for Escherichia coli membranes. Given the important role of cardiolipin (CL) in natural membranes, a ternary model system, POPE/POPG/CL, was then considered. The results obtained in these mimetic systems were compared with those obtained for the natural systems E. coli polar and total lipid extract. DLS and fluorescence anisotropy are not commonly used to study lipid phase transitions, but it was shown that they can give useful information about the thermotropic behaviors of model systems for bacterial membranes. These two techniques provided very similar results, validating their use as methods to measure phase transitions in lipid model systems. The temperature transitions obtained from these two very different techniques and the AFM results clearly show that cardiolipin is a fundamental component to mimic bacteria membranes. The results suggest that the less commonly used ternary system is a considerably better mimic for natural E. coli membranes than binary lipid mixture.

Capsule endoscopy assisted by traditional upper endoscopy

BACKGROUND AND AIMS

Capsule endoscopy (CE) can be prevented by difficulties in swallowing the device and/or its gastric retention. In such cases, endoscopic delivery of the capsule to duodenum is very useful. We describe the indications and outcomes of cases in which traditional endoscopic techniques allowed placement of the capsule in duodenum.

PATIENTS AND METHODS

This is a retrospective, descriptive case series. All patients in the above conditions were identified and indications for CE, endoscopic-placement technique, complications and completeness of small bowel imaging were registered.

RESULTS

Endoscopic-assisted delivery of the capsule was necessary in 13 patients (2.1% of all CE; 7 males; mean age--47.9 +/- 24.9 years, range 13 to 79 years). Indications for endoscopic delivery included: inability to swallow the capsule (7), gastric retention in previous exams (3), abnormal upper gastrointestinal anatomy (3). In eight patients, the capsule was introduced in GI tract with: foreign body retrieval net alone (3), retrieval net and a translucent cap (2), prototype delivery device (2) or a polypectomy snare (1). Five patients ingested the capsule that was then placed in duodenum with a polypectomy snare (3) or a retrieval net (2). No major complications occurred. Complete small bowel examination was possible in 10 patients (77%).

CONCLUSIONS

Endoscopic placement of capsule endoscope in the duodenum is rarely needed. However it may be safely performed by different techniques avoiding some limitations of CE. The best methods for endoscopic delivery of the capsule in the duodenum seem to be retrieval net with a translucent cap when the patient is unable to swallow the device or a retrieval net only to capture the capsule in the stomach when the patients swallows it easily.

Supplementation requirements of brewery's spent grain hydrolysate for biomass and xylitol production by Debaryomyces hansenii CCMI 941

The effect of nutrient supplementation of brewery's spent grain (BSG) hydrolysates was evaluated with respect to biomass and xylitol production by Debaryomyces hansenii. For optimal biomass production, supplementation of full-strength BSG hydrolysates required only phosphate (0.5 g l(-1) KH(2)PO(4)), leading to a biomass yield and productivity of 0.60 g g(-1) monosaccharides and 0.55 g l(-1 )h(-1), respectively. Under the conditions studied, no metabolic products other than CO(2) and biomass were identified. For xylitol production, fourfold and sixfold concentrated hydrolysate-based media were used to assess the supplementation effects. The type of nutrient supplementation modulated the ratio of total polyols/total extracellular metabolites as well as the xylitol/arabitol ratio. While the former varied from 0.8 to 1, the xylitol/arabitol ratio reached a maximum value of 2.6 for yeast extract (YE)-supplemented hydrolysates. The increase in xylitol productivity and yield was related to the increase of the percentage of consumed xylose induced by supplementation. The best xylitol yield and productivity were found for YE supplementation corresponding to 0.55 g g(-1) and 0.36 g l(-1 )h(-1), respectively. In sixfold concentrated hydrolysates, providing that the hydrolysate was supplemented, the levels of xylitol produced were similar or higher than those for arabitol. Xylitol yield exhibited a further increase in the sixfold hydrolysate supplemented with trace elements, vitamins and minerals to 0.65 g g(-1), albeit the xylitol productivity was somewhat lower. The effect of using activated charcoal detoxification in non-supplemented versus supplemented sixfold hydrolysates was also studied. Detoxification did not improve polyols formation, suggesting that the hemicellulose-derived inhibitor levels present in concentrated BSG hydrolysates are well tolerated by D. hansenii.

Does aliphatic chain length influence carbocyanines' orientation in supported lipid multilayers?

UV-Vis linear dichroism was used to study the orientation of 3,3'-dihexyloxacarbocyanine (DiOC6(3)) and 3,3'-dihexadecyloxacarbocyanine (DiOC16(3)) in supported multilayers of dipalmitoylphosphatidylcholine (DPPC) and dilauroylphosphatidylcholine (DLPC). Orientational probability density functions were similar for the two carbocyanines in both lipids. Multimodal distributions were found in all cases. The main peak is at 9 degrees-11 degrees relative to the bilayer normal axis, except for DiOC16(3) in DLPC multilayers (main peaks at 13 degrees and 90 degrees). Quenching studies revealed that the two carbocyanines are localized at the interface region of the membrane regardless of the lipid matrix they are inserted in. Combining these data with linear dichroism results lead to the conclusion that both the aliphatic chain length of carbocyanines and the lipid phase have little influence in the structural organization of these probes in lipidic bilayers. The partition constants of DiOC6 (3), K(p), were determined from fluorescence anisotropy measurements; the values obtained were K(p) (DPPC) = (2.39 +/- 0.05) x 10(3) and K(p) (DLPC) = (5.01 +/- 1.15) x 10(3).

Salivary IgA to cariogenic bacteria in HIV-positive children and its correlation with caries prevalence and levels of cariogenic microorganisms

The interrelationship of HIV infection, dental caries and mucosal immune responses remains controversial. In our study population of 40 HIV-infected and 40 healthy control children (ages 2-5 years) there was a significantly higher prevalence of dental caries in HIV-infected children (P<0.05). The extent of caries correlated with the severity of HIV disease. To determine whether the immunosuppression that ensues after HIV infection could contribute to the increased caries prevalence, the concentrations of total IgA and IgA specific to cariogenic bacteria (Streptococcus mutans, Streptococcus sobrinus and Lactobacillus acidophilus) were determined in whole saliva by enzyme-linked immunosorbent assay. Levels of the same bacteria were also quantified in saliva using checkerboard DNA-DNA hybridization. A significantly increased level of total salivary IgA was found in the HIV-positive population (P < 0.05), but there were comparable titers of specific IgA to cariogenic bacteria in HIV-positive and healthy controls. The microbiological assessment also demonstrated similar levels of cariogenic microorganisms in both groups. We conclude that HIV-positive children appear to maintain the capacity to mount a mucosal immune response to cariogenic microorganisms, at least until late stages of disease.

Active genes dynamically colocalize to shared sites of ongoing transcription

The intranuclear position of many genes has been correlated with their activity state, suggesting that migration to functional subcompartments may influence gene expression. Indeed, nascent RNA production and RNA polymerase II seem to be localized into discrete foci or 'transcription factories'. Current estimates from cultured cells indicate that multiple genes could occupy the same factory, although this has not yet been observed. Here we show that, during transcription in vivo, distal genes colocalize to the same transcription factory at high frequencies. Active genes are dynamically organized into shared nuclear subcompartments, and movement into or out of these factories results in activation or abatement of transcription. Thus, rather than recruiting and assembling transcription complexes, active genes migrate to preassembled transcription sites.

Oral subchronic toxicity of aqueous crude extract of Plantago australis leaves

The toxic effects of chronic oral administration (60 days) of aqueous crude extract (AE) of Plantago australis Lam. (Plantaginaceae) in rats at doses of 850 and 1700 mg/kg on biochemical (ALT, AST, creatinine, urea, glucose, alkaline phosphatase, total proteins and albumin), hematological (complete hemogram), and histopathological (heart, lung, liver, kidney, esophagus, stomach and gut) parameters were studied. All biochemical and hematological parameters were found to be in the normal range, but ALT in animals that received AE of 850 mg/kg was higher. Histopathological analysis of organs, especially the liver did not present alterations.

Epigenetic modifications in an imprinting cluster are controlled by a hierarchy of DMRs suggesting long-range chromatin interactions

Imprinted genes and their control elements occur in clusters in the mammalian genome and carry epigenetic modifications. Observations from imprinting disorders suggest that epigenetic modifications throughout the clusters could be under regional control. However, neither the elements that are responsible for regional control, nor its developmental timing, particularly whether it occurs in the germline or postzygotically, are known. Here we examine regional control of DNA methylation in the imprinted Igf2-H19 region in the mouse. Paternal germline specific methylation was reprogrammed after fertilization in two differentially methylated regions (DMRs) in Igf2, and was reestablished after implantation. Using a number of knockout strains in the region, we found that the DMRs themselves are involved in regional coordination in a hierarchical fashion. Thus the H19 DMR was needed on the maternal allele to protect the Igf2 DMRs 1 and 2 from methylation, and Igf2 DMR1 was needed to protect DMR2 from methylation. This regional coordination occurred exclusively after fertilization during somatic development, and did not involve linear spreading of DNA methylation, suggesting a model in which long-range chromatin interactions are involved in regional epigenetic coordination. These observations are likely to be relevant to other gene clusters in which epigenetic regulation plays a role, and in pathological situations in which epigenetic regulation is disrupted.

Deletion of a silencer element in Igf2 results in loss of imprinting independent of H19

Igf2 and H19 are closely linked, reciprocally imprinted genes on mouse distal chromosome 7. The paternally expressed Igf2 encodes a potent fetal growth factor and the maternally expressed H19 encodes a non-coding RNA (refs 1,2). Shared endoderm-specific enhancers 3' to H19 are necessary for transcription of the maternal copy of H19 and the paternal copy of Igf2 (ref. 3), a chromatin boundary upstream of H19 preventing access of the enhancers to the maternal Igf2 promoters. Mesoderm-specific control elements have not been identified, and the role of differentially methylated regions (DMRs) in Igf2 has not been addressed. Two DMRs in Igf2 are methylated on the active paternal allele, suggesting that they contain silencers. Here we have deleted the DMR1 region in Igf2. Maternal transmission of the deletion results in biallelic expression of Igf2 in most mesodermally derived tissues without altering H19 imprinting or expression. Paternal or maternal transmission leads to continued postnatal transcription of Igf2, in contrast to the wild-type allele, which is silenced soon after birth. These results reveal a mesodermal silencer, which may be regulated by methylation and which has a major role in H19-independent expression and imprinting control of Igf2. Our results establish a new mechanistic principle for imprinted genes whereby epigenetically regulated silencers interact with enhancers to control expression, and suggest a new mechanism for loss of imprinting (LOI) of Igf2, which may be important in a number of diseases.

DNA damage in round spermatids of mice with a targeted disruption of the Pp1cgamma gene and in testicular biopsies of patients with non-obstructive azoospermia

Non-obstructive azoospermia accounts for a considerable proportion of male factor infertility. Current therapies for treatment of this kind of infertility include procedures such as intracytoplasmic sperm injection (ICSI), round spermatid injection (ROSI), round spermatid nucleus injection (ROSNI) and elongated spermatid injection (ELSI). All involve injection of haploid germ cells retrieved from testicular biopsies into recipient oocytes. We have investigated a mouse model of azoospermia for quality of haploid germ cell genomes, based on 4,6-diamidino-2-phenylindole (DAPI)/TdT-mediated dUTP nick-end labelling (TUNEL) labelling. The mouse model, a targeted mutation in the protein phosphatase 1cg gene, results in severe depletion of haploid germ cells from the round spermatid stage on. Mice homozygous for the mutation are completely infertile, and produce only the occasional spermatozoon. Spermatozoa and round spermatids retrieved from either the epididymides or the testes of mutant mice displayed very high rates of DNA fragmentation. In contrast, similar cells retrieved from heterozygous or wild-type littermates displayed low levels of DNA fragmentation. In some cases, the high rates of DNA fragmentation in mutant cells could be lowered by inclusion of antioxidants in the retrieval media. High rates of DNA fragmentation were also observed in round spermatids retrieved from testicular biospies of human patients with non-obstructive azoospermia. These results suggest that one of the features of the pathology associated with azoospermia is fragmented DNA in haploid germ cells. This raises questions about the suitability of using these cells for fertility treatment.

Reactive oxygen species: potential cause for DNA fragmentation in human spermatozoa

The objective of this study was to evaluate the effect of the generation of reactive oxygen species (ROS) on the integrity of the DNA of human spermatozoa, and to determine if pretreatment with antioxidants can reduce DNA damage. Samples were obtained from 47 men undergoing infertility investigation. ROS were generated in the samples by the addition of xanthine/xanthine oxidase (X/XO) with or without antioxidants. After incubation at timed intervals (0-2 h) with X/XO, the percentage of spermatozoa with DNA fragmentation was determined using the method of TdT-mediated DNA end-labelling (TUNEL). Time intervals were selected to mimic the clinical situation in which spermatozoa are held for a period of time after swim-up while the oocytes are prepared for ICSI. A significant increase in sperm DNA damage was evident when samples were incubated in the presence of ROS for intervals of 1 and 2 h, but not when incubated with ROS for <1 h (P = 0.0001). The addition of antioxidants significantly decreased the amount of DNA damage induced by ROS generation (P < 0.04). ROS can cause an increase in DNA fragmentation and pretreatment with antioxidants can reduce DNA damage.

Gamete-specific DNA fragmentation in unfertilized human oocytes after intracytoplasmic sperm injection

The objective of the present study was to assess the integrity of maternal and/or paternal chromatin in injected oocytes that remained unfertilized after intracytoplasmic sperm injection (ICSI). The study was performed on 102 oocytes that failed to show pronuclear formation 18-20 h after ICSI. We used chromatin labelling with 4,6-diamidino-2-phenylindole (DAPI) to identify maternal and paternal chromatin, coupled with biotin-mediated end-labelling to assess DNA fragmentation in each gamete. It was shown that 50% of oocytes without pronuclear formation following ICSI contained chromatin with damaged DNA, and that the source of the DNA fragmentation was equally divided between the spermatozoon (25.8%) and the oocyte (24.4%). A significantly greater proportion of condensed spermatozoa in human oocytes had damaged DNA, compared to decondensed spermatozoa (24.7 compared to 5.9%, P=0.002). There was a significant increase in the incidence of DNA fragmentation in oocytes from patients older than 35 years (65+/-1.2%) compared to those from younger patients (36+/-1.0%) (P < 0.05). Further, 17% of unfertilized oocytes contained no paternal chromatin. Thus, DNA fragmentation in both spermatozoa and oocytes is associated with failure of fertilization in ICSI. In some cases of severe male factor infertility, a significant proportion of spermatozoa injected into oocytes may contain fragmented DNA. Injection of oocytes with spermatozoa containing abnormal chromatin will probably result in failure of sperm decondensation and fertilization. In older women, a significant proportion of oocytes injected may contain fragmented DNA. These observations may explain the consistent inability of most clinics to achieve fertilization rates higher than 65% with ICSI.

Sperm deoxyribonucleic acid fragmentation is increased in poor-quality semen samples and correlates with failed fertilization in intracytoplasmic sperm injection

OBJECTIVE

To determine the incidence of DNA fragmentation in human sperm used for intracytoplasmic sperm injection (ICSI) and to correlate any detected DNA damage with semen analysis parameters and fertilization rates in ICSI.

DESIGN

Descriptive and correlational clinical study.

SETTING

Tertiary care fertility clinic.

PATIENT(S)

A total of 150 semen samples was collected from men in the ICSI program.

INTERVENTION(S)

For each sample, sperm wash and swim-up were performed, and the percentage of recovered sperm with DNA fragmentation was determined with the use of terminal transferase-mediated deoxyuridine triphosphate-biotin end labeling.

MAIN OUTCOME MEASURE(S)

The percentage of sperm with DNA fragmentation was correlated with semen analysis parameters and ICSI fertilization rates.

RESULTS(S)

The mean (+/- SD) percentage of sperm with fragmented DNA was 14.5% +/- 1.5% and ranged from 0.5% to 75%. A significant negative association was found between the percentage of sperm with DNA fragmentation and the ICSI fertilization rate. We also observed that the motility and morphology of the ejaculated sperm were correlated negatively with the percentage of DNA fragmentation in the washed sperm recovered by the swim-up technique.

CONCLUSION(S)

Our results suggest that when poor-quality semen samples are used for ICSI, there is a greater likelihood that some sperm selected for injection, despite appearing normal, contain fragmented DNA. Whether sperm DNA damage may contribute to failure of pronuclear formation and embryo development in some apparently unfertilized ICSI oocytes is unclear.

[Prospective registry of cerebrovascular diseases. Characterization of patients and methodology evaluation]

Hospital-based stroke data banks can contribute to a better management of stroke patients with consequent reduction of associated morbidity and mortality.

OBJECTIVE

The characterisation of stroke patients and validation of the hospital stroke registry.

SETTING

Hospital S.Pedro, Vila Real, a secondary neurological referral centre for 450.000 inhabitants of interior north Portugal.

PATIENTS AND METHODS

Analysis of data collected over one year of a prospective computerised stroke registry. Evaluation of completeness of the registry by independent analysis from emergency room data files and percentage of items entirely filled up.

RESULTS

in a one year period were registered 349 patients (186 F; 163 M) with a mean age at stroke of 69 years. The majority (73.3%) lived in the hospital district. Most patients went directly to the hospital from their homes, and in the first 24 hours of symptoms onset. Cerebral infarction was diagnosed in 35.2% of patients, followed from lacunas in 24.6% and hypertensive haemorrhages in 22.3%. Arterial hypertension was found in 60.1% of cases, there were 11.4% of deaths and a Rankin score > 3 was present at hospital discharge in 39.5% of patients. There was a decrease in the register during the one-year period, evaluated comparing two months of emergency room files; we found a missing rate of protocols items varying from 0.8% and 8.8%.

CONCLUSIONS

Hospital-based stroke data banks can provide the best available information on stroke patients characteristics and the presence of stroke risk factors. Registry protocols must be kept simple, easy to fill and periodically surveyed in order to lessen the number of missing items.

[Evaluation of the Cell-DYN 35))]

The Cell-Dyn 3500 is an automated haematology analyzer which quantitatively measures and computes haematological quantities including a full "five-part" white cell differential. It measures 22 parameters for erythrocytes, white blood cells and platelets, also giving the respective histograms. Evaluation of the Cell-Dyn 3500 was performed according to the International Committee for Standardization in Haematology (ICSH) norms, for a period of 5 weeks. A total of 1,235 samples were studied by comparison with the Coulter MaxM. The five-part white cell differential and the flagging system were estimated and compared with the smear examination of 506 samples, by four clinical pathologists trained in cytology. Good correlation was obtained within, between batches, and day-to-day, for the following parameters: red blood cells (RBC), haemoglobin (HGB), mean cell volume (MCV), white blood cells (WBC) and platelets (PLT). The accuracy was estimated (RBC, HGB, VGM, WBC and PLT) each day with three different levels of titrated controls with good results. The linearity was established for RBC, HGB, WBC and PLT. The results obtained were good. Carry-over studies were performed according to the Broughton method for the same parameters and the results were also good. Stability studies for the automatic parameters including the differential white blood cell count showed that these parameters were stable at 4 degrees C for 48 hours. At room temperature the stability was reduced to 7 hours. Agreement was good between the Cell-Dyn 3500 and the Coulter MaxM, for the automatic haemocytometric values. The comparative studies between the five-part white cell differential of the haematologic analyzer and the manual differential showed excellent results for neutrophils and lymphocytes, very good for monocytes and eosinophils. For the flag estimation two criteria were established, one based on the clinical significance and the other based on the alarm detection described in the analyzer manual. The specificity was good for both criteria. In general the sensibility was better for the second criteria. The Cell-Dyn 3500 has thus shown to be a good haematology analyser which greatly reduces the morphological examination of smears.

[Urinary calcium, magnesium and uric acid in normal children]

In a group of 327 normal children, aged 4 to 11, we measured Calcium (Ca) and Creatinine (Cr) in the second morning urine. In 226 of them, Magnesium (Mg) and Uric Acid (UA) were also calculated. Means and SD were respectively Ca/Cr: 0.11 +/- 0.09, Mg/Cr: 0.10 +/- 0.03, Mg/Ca: 1.56 +/- 1.48 and UA/Cr: 0.093 +/- 0.29. Distribution was not normal, so we used the 97.5 centile for the upper acceptable limit. This value was higher for Ca/Cr (0.37) and different for Mg/Cr (0.17), compared to the previous reports. Our values of Mg/Ca were related to age (p less than 0.01). These results suggest the need for local establishment of normal ranges and a better definition of hypercalciuria and hypermagnesiuria.

Thermogenesis from intravenous medium-chain triglycerides

Eighteen hospitalized patients dependent on total parenteral nutrition (TPN) were randomly enrolled into a prospective study comparing intravenous long-chain triglycerides (LCT) with a physical mixture of 75% medium-chain triglycerides (MCT) and 25% LCT. The TPN was given continuously as amino acids and glucose over 5 days with the respective lipid emulsion given intermittently during each day for 10 hr. Indirect calorimetry was measured on each patient before the lipid emulsion was administered in the morning and again 10 hr later near the end of the lipid infusion, on days 1, 3, and 5. Resting energy expenditure, VO2, VCO2, and calculated fat oxidation were shown to increase during MCT infusion but not during LCT administration, (resting energy expenditure 899 +/- 37 to 1085 +/- 40, compared with 978 +/- 23 to 976 +/- 39, kcal/m2 body surface area [BSA]/day, respectively, p less than 0.0002; VO2: 129.9 +/- 5.2 to 157.2 +/- 5.9, compared with 140.9 +/- 3.6 to 141.2 +/- 5.9 ml O2/min/m2 BSA, respectively, p less than 0.0005; and VCO2: 110.7 +/- 4.4 to 127.5 +/- 4.3, compared with 118.3 +/- 2.8 to 118.0 +/- 5.3, ml CO2/min/m2 BSA, respectively, p less than 0.0076; calculated fat oxidation 10.7 +/- 1.5 to 19.3 +/- 2.4, compared with 20.0 +/- 2.7 to 20.0 +/- 3.6, kcal/m2 BSA/hr, respectively, p less than 0.014). Respiratory quotient tended to fall with lipid infusion but did not change statistically. Body temperatures were unaltered by either fat infusion. It is concluded that TPN consisting of MCT causes an increased thermogenesis, most likely through increased fat oxidation, reflective of MCT's property as an obligate fuel. The increased thermogenesis occurs without an increase in body temperature.

Serum fatty acid profiles after intravenous medium chain triglyceride administration

The serum fatty acid profiles of patients receiving either intravenous medium or long chain triglycerides were studied. Seventeen hospitalized patients, dependent on total parenteral nutrition, were randomly enrolled into a prospective study. The total parenteral nutrition (TPN) delivered amino acids and glucose and either a 75% medium chain triglyceride and 25% long chain triglyceride (MCT group) physical mixture or all long chain triglyceride (LCT group), as the respective fat sources. The amino acids and glucose were given continuously, and the lipid was given for 10 hours each day over five days. Fatty acid profiles on serum triglycerides and free fatty acids were done in the morning before any lipid was given and also later in the afternoon, near the end of the lipid administration, on days 1, 3 and 5. Medium chain fatty acids rose quickly in the triglyceride fraction in patients given MCT. Rapid MCT hydrolysis occurred as evidenced by the appearance of medium chain fatty acids in the free fatty acid fraction in the afternoon sampling. Clearance of the hydrolyzed medium chain free fatty acids (MCFFA) occurred so that little, if any, were present in the morning sampling one day later. Long chain fatty acids, as either triglycerides or free fatty acids, showed expected increases during the daily infusion, but not of such relative magnitude as the medium chain fatty acids. Medium chain fatty acid incorporation into the phospholipid or cholesterol ester fractions by the end of the five-day feeding period was present but minimal.(ABSTRACT TRUNCATED AT 250 WORDS)

[A dynamic study of HGH, zinc and copper in diabetic girls. Preliminary report]

A dynamic study study on secretion of HGH in diabetic girls under the combined stimulus of L-dopa and L-arginina is performed. Serum levels for Zinc and copper are measured. Results show that as HGH increase, copper levels decrease. Correlation (r = 0.81, p = 0.05) points to an inverse dependence of both parameters. Concomitantly, the values obtained for zinc and copper are correlated (r = 0.82, p = 0.03). During stimulation, all patients showed an increase in glycemia and a significant correlation between both parameters was found (r = 0.76, p = 0.05).