Internal quality control indicators in cervical cytopathology of a university laboratory.

INTRODUCTION: To evaluate the internal quality control indicators and quality management programme in a university cytopathology laboratory. METHODS: All results of conventional cervical smears tests (taken from the SISCAN, the Brazilian cervical cancer screening system) of women aged ≥15 years at the time of Papanicolaou smear specimen collection during January 2007-December 2014 were included. The final results of the cytopathology were classified in accordance with the Bethesda System. The variables included in the database were the woman's name, date of birth, and age at the time of sampling (15-30, 31-40 and older than 40 years). RESULTS: In this period, 50 286 cytopathology examinations were carried out. Of these, 44 386 (91.34%) were negative for malignancy or unsatisfactory and 4209 (8.66%) presented epithelial abnormalities. The percentage of the tests consistent with atypical squamous cells (ASC) between satisfactory examinations was 4.12%; the percentage of tests compatible with ASC among abnormal examinations was 47.87%; the ASC/squamous intraepithelial lesion) ratio was 0.97 and the percentage of high-grade squamous intraepithelial lesion among satisfactory tests was 2.21%, and the 5-year retrospective review identified 4.97% of false-negative results. CONCLUSION: All rates obtained were consistent over the years and within the recommended values by Federal Regulation of Brazil. This demonstrates the efficacy of our established internal quality monitoring and continuing education, reflecting the commitment of the team involved in the release of smear reports.

Behavioral aspects of Lutzomyia longipalpis (Diptera: Psychodidae) in urban area endemic for visceral leishmaniasis.

The study of some of the behavioral aspects of the main vector of Leishmania infantum chagasi Cunha & Chagas in the Americas, Lutzomyia longipalpis (Lutz & Neiva), such as dispersion, population size, and vector survival rates, is important for the elucidation of the mechanisms of visceral leishmaniasis transmission. These parameters were studied by means of capture-mark-release-recapture experiments in an urban area of Campo Grande municipality, an endemic area of visceral leishmaniasis, situated in Mato Grosso do Sul state, Brazil. Six capture-mark-release-recapture experiments were undertaken between November 2009 and November 2010 and once in January 2012 with a view to assessing the population size and survival rate of Lu. longipalpis. The insects were released in a peridomicile surrounded by 13 residences. The recaptures were undertaken with automatic light traps for four consecutive weeks after release in the surrounding area. In total, 3,354 sand flies were captured, marked, and released. The overall recapture rate during the capture-mark-release-recapture experiments was 4.23%, of which 92.45% were recaptured at the release site, indicating limited dispersal. The greatest distance recorded from the release site was 165 m for males and 241 m for females. The male daily survival rate, calculated on the basis of regressions from the numbers of marked recaptured insects during the 15 successive days after release was 0.897. The estimated male population size measured by the Lincoln Index was 10,947.127. Though Lu. longipalpis presented a limited dispersion the physical barriers typical of urban environments did not prevent the sand flies from flying long distances.

Histological characterization and immunohistochemical localization of ki-67 and VEGF factors in bitches' corpus luteum at cyclic and early and late gestational diestrous.

The luteal phase on pregnant and non-pregnant bitches is characteristic of this species and resembles significantly with respect to the growth pattern and luteal regression. Histological and immunostaining studies of the corpus luteum (CL) may help to elucidate differences between the CL of pregnant and non-pregnant bitches. The purpose of this study was to characterize histologically and localize by immunohistochemistry the cell proliferation (Ki-67) and vascular endothelial growth (VEGF) factors in the CL of pregnant and non-pregnant bitches. Eighteen bitches were analysed and distributed into three groups: In group I (gestational diestrous), seven bitches were subjected to two inseminations at 4 and 6 days after the pre-ovulatory LH surge and ovariohysterectomized (OSH) at 8-21 days after the first insemination. In group II (cyclic diestrous; control), 6 (Ki-67) or 8 (VEGF) bitches that were determined as non-pregnant were OSH at 12-25 days of the pre-ovulatory LH surge. In group III (late pregnancy), three bitches had their ovary removed during caesarean section at 62-64 days after the pre-ovulatory LH surge. Portions of the ovarian cortex containing CLs were cut and stored for histological and immunohistochemical analysis. Histological evaluation of the ovarian cortex showed a marked similarity in the morphological pattern among the CLs in all three groups. The morphology and expression pattern of VEGF and Ki-67 factors in CLs of cyclic and gestational diestrous bitches were similar but significantly lower than that of late pregnant bitches (p < 0.05).

Distinct Microbial Signatures between Periodontal Profile Classes.

Precise classification of periodontal disease has been the objective of concerted efforts and has led to the introduction of new consensus-based and data-driven classifications. The purpose of this study was to characterize the microbiological signatures of a latent class analysis (LCA)-derived periodontal stratification system, the Periodontal Profile Class (PPC) taxonomy. We used demographic, microbial (subgingival biofilm composition), and immunological data (serum IgG antibody levels, obtained with checkerboard immunoblotting technique) for 1,450 adult participants of the Dental Atherosclerosis Risk in Communities (ARIC) study, with already generated PPC classifications. Analyses relied on t tests and generalized linear models with Bonferroni correction. Men and African Americans had higher systemic antibody levels against most microorganisms compared to women and Caucasians (P < 0.05). Healthy individuals (PPC-I) had low levels of biofilm bacteria and serum IgG levels against most periodontal pathogens (P < 0.05). Subjects with mild to moderate disease (PPC-II to PPC-III) showed mild/moderate colonization of multiple biofilm pathogens. Individuals with severe disease (PPC-IV) had moderate/high levels of biofilm pathogens and antibody levels for orange/red complexes. High gingival index individuals (PPC-V) showed moderate/high levels of biofilm Campylobacter rectus and Aggregatibacter actinomycetemcomitans. Biofilm composition in individuals with reduced periodontium (PPC-VI) was similar to health but showed moderate to high antibody responses. Those with severe tooth loss (PPC-VII) had significantly high levels of multiple biofilm pathogens, while the systemic antibody response to these microorganisms was comparable to health. The results support a biologic basis for elevated risk for periodontal disease in men and African Americans. Periodontally healthy individuals showed a low biofilm pathogen and low systemic antibody burden. In the presence of PPC disease, a microbial-host imbalance characterized by higher microbial biofilm colonization and/or systemic IgG responses was identified. These results support the notion that subgroups identified by the PPC system present distinct microbial profiles and may be useful in designing future precise biological treatment interventions.

Metabolomics Insights in Early Childhood Caries.

Dental caries is characterized by a dysbiotic shift at the biofilm-tooth surface interface, yet comprehensive biochemical characterizations of the biofilm are scant. We used metabolomics to identify biochemical features of the supragingival biofilm associated with early childhood caries (ECC) prevalence and severity. The study's analytical sample comprised 289 children ages 3 to 5 (51% with ECC) who attended public preschools in North Carolina and were enrolled in a community-based cross-sectional study of early childhood oral health. Clinical examinations were conducted by calibrated examiners in community locations using International Caries Detection and Classification System (ICDAS) criteria. Supragingival plaque collected from the facial/buccal surfaces of all primary teeth in the upper-left quadrant was analyzed using ultra-performance liquid chromatography-tandem mass spectrometry. Associations between individual metabolites and 18 clinical traits (based on different ECC definitions and sets of tooth surfaces) were quantified using Brownian distance correlations (dCor) and linear regression modeling of log2-transformed values, applying a false discovery rate multiple testing correction. A tree-based pipeline optimization tool (TPOT)-machine learning process was used to identify the best-fitting ECC classification metabolite model. There were 503 named metabolites identified, including microbial, host, and exogenous biochemicals. Most significant ECC-metabolite associations were positive (i.e., upregulations/enrichments). The localized ECC case definition (ICDAS ≥1 caries experience within the surfaces from which plaque was collected) had the strongest correlation with the metabolome (dCor P = 8 × 10-3). Sixteen metabolites were significantly associated with ECC after multiple testing correction, including fucose (P = 3.0 × 10-6) and N-acetylneuraminate (p = 6.8 × 10-6) with higher ECC prevalence, as well as catechin (P = 4.7 × 10-6) and epicatechin (P = 2.9 × 10-6) with lower. Catechin, epicatechin, imidazole propionate, fucose, 9,10-DiHOME, and N-acetylneuraminate were among the top 15 metabolites in terms of ECC classification importance in the automated TPOT model. These supragingival biofilm metabolite findings provide novel insights in ECC biology and can serve as the basis for the development of measures of disease activity or risk assessment.

Diabetes mellitus-related morphoquantitative changes in the celiac ganglion neurons of the dog.

Diabetes mellitus is the most common endocrine disturbance of domestic carnivores and can cause autonomic neurological disorders, although these are still poorly understood in veterinary medicine. There is little information available on the quantitative adaptation mechanisms of the sympathetic ganglia during diabetes mellitus in domestic mammals. By combining morphometric methods and NADPH-diaphorase staining (as a possible marker for nitric oxide producing neurons), type I diabetes mellitus-related morphoquantitative changes were investigated in the celiac ganglion neurons in dogs. Twelve left celiac ganglia from adult female German shepherd dogs were examined: six ganglia were from non-diabetic and six from diabetic subjects. Consistent hypertrophy of the ganglia was noted in diabetic animals with increase of 55% in length, 53% in width, and 61.5% in thickness. The ordinary microstructure of the ganglia was modified leading to an uneven distribution of the ganglionic units and a more evident distribution of axon fascicles. In contrast to non-diabetic dogs, there was a lack of NADPH-diaphorase perikarial labelling in the celiac ganglion neurons of diabetic animals. The morphometric study showed that both the neuronal and nuclear sizes were significantly larger in diabetic dogs (1.3 and 1.39 times, respectively). The profile density and area fraction of NADPH-diaphorase-reactive celiac ganglion neurons were significantly larger (1.35 and 1.48 times, respectively) in non-diabetic dogs compared to NADPH-diaphorase-non-reactive celiac ganglion neurons in diabetic dogs. Although this study suggests that diabetic neuropathy is associated with neuronal hypertrophy, controversy remains over the possibility of ongoing neuronal loss and the functional interrelationship between them. It is unclear whether neuronal hypertrophy could be a compensation mechanism for a putative neuronal loss during the diabetes mellitus.

Muscular dystrophy-related quantitative and chemical changes in adenohypophysis GH-cells in golden retrievers.

Duchenne muscular dystrophy (DMD) is a recessive X-linked lethal condition which affects a boy in every 3300 births. It is caused by the absence of dystrophin, a protein occurring especially within the musculoskeletal system and in neurons in specific regions of the central nervous system (CNS). Growth hormone (GH) inhibition is believed to decrease the severity of DMD and could perhaps be used in its treatment. However, the underlying pathological mechanism is not known. The golden retriever muscular dystrophy dog (GRMD) represents an animal model in the study of DMD. In this paper we investigated the morphological aspects of the adenohypophysis as well as the total number and size of GH-granulated cells using design-based stereological methods in a limited number of dystrophic and healthy golden retrievers. GH-cells were larger (32.4%) in dystrophic dogs than in healthy animals (p=0.01) and they occupied a larger portion (62.5%) of the adenohypophysis volume (p=0.01) without changes in either adenohypophysis volume (p=0.893) or total number of GH-granulated cells (p=0.869). With regard to ultrastructure, granulated cells possessed double-layer electron-dense granules which were evenly distributed in the cytosol. Furthermore, these granules in dystrophic animals occupied a larger proportion of GH-granulated cell volume (66.9%; p=0.008) as well as of all GH-cells in the whole pars distalis of adenohypophysis (77.3%; p=0.035), albeit IGF-1 serum concentration was lower in severe cases. This suggests difficulties in the GH secretion that might possibly be associated to dystrophin absence. In contrast to earlier reports, our data suggest that a lower IGF-1 concentration may be more related to a severe, as opposed to a benign, clinical form of muscular dystrophy.

Rituximab in refractory autoimmune diseases: Brazilian experience with 29 patients (2002-2004).

OBJECTIVE: Rituximab, a monoclonal antibody against B-lymphocytes that express CD 20, is already available for the treatment of non-Hodgkin's lymphoma. Due to the increased relevance of B-cell regulation in the pathogenesis of autoimmune diseases, rituximab is being used in the treatment of patients whose condition is refractory to conventional therapy. METHODS: We retrospectively evaluated the short-term efficacy and tolerance of rituximab in patients with various autoimmune diseases who were treated at the Hospital Israelita Albert Einstein in the city of Sao Paulo. RESULTS: During the period 2002-2004, 29 patients with various autoimmune diseases were treated with rituximab 375 mg/m2 for 4 consecutive weeks, or two doses of 1 g 2 weeks apart. We observed remarkable short-term results in all cases, except for one patient with thrombocytopenic purpura. Of note, we describe the results in two patients with diseases not previously treated with rituximab (hypergammaglobulinemic purpura of Waldenstrom and eosinophilic fasciitis with hypergammaglobulinemia). Treatment was well tolerated, with no unexpected adverse events. We also observed a marked reduction in steroid dosage. CONCLUSION: Rituximab seems to be safe and effective in the treatment of patients with a variety of autoimmune diseases that are refractory to other modalities of treatment.

Chaotropic anion-phosphatidylcholine membrane interactions: an ultra high field NMR study.

NMR studies on the interaction of the linear chaotropic anions, SCN- and SeCN-, with sonicated egg phosphatidylcholine (EPC) vesicles have been carried out at field strengths up to 14.1 Tesla. At 600 MHz, both anions cause splitting or increased splitting of the choline N+(CH3)3, CH2N+ and O3POCH2 1H resonances with SeCN- being somewhat more effective in this action than is SCN-. No changes were observed in the glycerol CH2OP and CH2OCO 1H resonances and the phosphate 31P resonance of the headgroup region. The 13C spectrum was unchanged by the presence of the anions. After 18 h of exposure to the anion, the 1H resonance splittings but not the chemical shift values returned to those prior to anion exposure. Increasing the temperature of the vesicles decreased the anion-induced splitting, but, upon return to the beginning temperature, the chemical shifts did not return to their original values. The results are considered in terms of the 'molecular electrometer' model recently developed by Seelig and co-workers [1].

A temperature study of diacetylenic phosphatidylcholine vesicles.

Dispersions of the diacetylenic phosphatidylcholine, 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine, DC8,9PC, undergo a change from vesicles to hollow tubes on cooling. We report here a light scattering and multinuclear NMR study of the lipid vesicles over the temperature range 0-50 degrees C. The 'splitting' of the N+(CH3)3 resonance increases with decreasing temperature, consistent with the light scattering measurements which show a decrease in vesicle size with decreasing temperature. The NMR spectrum remains well-resolved over this temperature range, even at temperatures as low as 3 degrees C. Phosphorus NMR also indicates that the 'bilayer structure' is maintained over this temperature range. The various proton resonances and the phosphorous signal from the lipid vesicles broaden as the temperature is lowered. These results will be helpful in developing a model for the tubule-forming ability of DC8,9PC.

Haploidentical BMT and post-transplant Cy for severe aplastic anemia: a multicenter retrospective study.

Patients with refractory severe aplastic anemia (SAA) who lack a matched sibling or unrelated donor need new therapeutic approaches. Hematopoietic SCT (HSCT) using mismatched or haploidentical related donors has been used in the past, but was associated with a significant risk of GVHD and mortality. Recently, the use of post-transplant cyclophosphamide (Cy) has been shown to be an effective strategy to prevent GVHD in recipients of haploidentical HSCT, but the majority of reports have focused on patients with hematology malignancies. We describe the outcome of 16 patients who underwent haploidentical transplantation using a reduced-intensity conditioning regimen with post-transplant Cy. Stem cell sources were BM (N=13) or PBSCs (N=3). The rate of neutrophil engraftment was 94% and of platelet engraftment was 75%. Two patients had secondary graft failure and were successfully salvaged with another transplant. Three patients developed acute GVHD being grades 2-4 in two. Five patients have died and the 1-year OS was 67.1% (95% confidence interval: 36.5-86.4%). In our small series, the use of a reduced-intensity conditioning with post-transplant Cy in haploidentical BMT was associated with high rates of engraftment and low risk of GVHD in patients with relapsed/refractory SAA.

Selectivity of human T lymphotropic virus type-1 (HTLV-1) and HTLV-2 infection among different populations in Brazil.

A seroprevalence study for human T lymphotropic virus type-1 (HTLV-1) and HTLV-2 was conducted in Sao Paulo, Brazil among 2,312 individuals that included following groups: 1,148 volunteer blood donors, 37 patients with tropical spastic paraparesis (TSP), 53 with lymphoproliferative disorders, 171 with a history of multiple blood transfusions, 268 human immunodeficiency virus type-1 (HIV-1) seropositive subjects, and 635 Amazonian Indians. Antibodies to HTLV-1/2 were screened by enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blot and/or radioimmunoprecipitation. The differentiation of HTLV-1 and HTLV-2 was achieved using a synthetic recombinant peptide (rgp46) ELISA. We confirmed the presence of HTLV-1 infection in Brazil, both in blood donors (0.4%) and in patients exposed to blood transfusions (2.9%), as well as the occurrence of HTLV-1-associated TSP (11 patients, or 30% of all TSP cases) and adult T cell leukemia/lymphoma (two cases, or 3.5% of all hematologic malignancies). The HIV-1 infected individuals were shown to be coinfected (8.9%) with either HTLV-1 or HTLV-2. All HIV-1 and HTLV-2 coinfected individuals were intravenous drug abusers. In addition, we also demonstrated the presence of HTLV-2 (4.7%), and HTLV-1/2 (0.8%) in tribes of Amazonian Indians who lived in the eastern Amazon basin (southeastern State of Para). The selectivity of these retroviral infections in particular groups is emphasized, as well as the need for HTLV-1/2 screening of all blood donors in Brazil as a public health measure.

PMR relaxation times of micelles of the nonionic surfactant Triton X-100 and mixed micelles with phospholipids.

Previous pmr studies at 220 MHz have led to the suggestion that phosphatidylcholine and the nonionic surfactant Trition-X-100 form mixed micellar structures at high molar ratios of trition to phosphalipid. These mixed micelles provide one form of the phospholipid which the enzyme phospholipase A2 can utilize as substrate. Spin-lattice relaxation times (T1) and spin-spin relaxation times (T2) obtained from line widths for resolvable protons in Triton X-100 micelles and mixed micelles with egg phosphatidycholine and dipalmitoyl phosphatidylcholine are reported. They suggest that the structure of the mixed micelles is generally similar to that of pure Triton X-100 micelles. The T1 values for the phsopholipid in the mixed micelles are found to be similar to those reported for phospholipid in sonicated vesicle preparations which are used as membrane models, but the lines are somewhat sharper suggesting the possibility of less anisotropic motion in the mixed micelles than in the vesicles.

The interaction of MRI contrast agents with phospholipids.

The molecular interactions of three clinically used MRI contrast agents with lipid vesicles, consisting of egg phosphatidylcholine (EPC), have been studied using high-field NMR techniques. At a molar ratio of one contrast agent molecule to five phospholipid molecules, a significant increase in the proton resonance line width occurred for certain lipid head group moieties. A large decrease in the T1 relaxation times for the head group moieties was also observed. These two effects occurred regardless of the ionic status and the chelate structure of the three contrast agents. The structure of the contrast agents did, however, affect the magnitude of the two NMR parameter changes. These NMR effects also differed in magnitude amongst the various head group entities. The NMR effects were greatest for the head group moieties at or near the vesicle-water interface. The results are discussed in terms of the structure of the phospholipid-water interface. Since the use of contrast agents has become routine in clinical MRI, our results are of importance in terms of the interaction of the agents with physiological surfaces, many of which contain phospholipids. The understanding of such interactions should be of value not only for improved diagnostics, but also in the development of new contrast agents.

[Antithrombin III concentrate use in patients with cirrhosis with coagulation disorders]. / Uso de concentrado de antitrombina III em cirróticos com distúrbios de coagulação.

BACKGROUND: Patients with severe hepatic failure present acquired deficiency of antithrombin III (ATIII) owing to reduced synthesis associated with intravascular activation of blood coagulation, which may be corrected by ATIII infusion. OBJECTIVE: The aim of this uncontrolled trial was to verify the effect of a standard dose of ATIII concentrate (Kybernin), that is, 50 U/kg of body weight per day, every 2 days, on ATIII levels in patients with severe hepatic failure and hemostatic imbalance. PATIENTS AND METHODS: Six cirrhotic patients were studied: mean age of 44 years (14 to 63 years), who presented at least 2 abnormal coagulation tests (PT > 1.40, APTT > 1.25, Fibrinogen < 1.5 g/dL, Platelet count < 80,000/mm3). Mean serum albumin was 2.6 g/dL (1.9 to 3.8 g/dL). Blood was drawn before infusion, 4 h after the first infusion, and just before the next infusion. ATIII levels were measured by amidolytic method. RESULTS: Mean ATIII levels were: initial = 35.8%, 4th h = 56.2%*, 2nd d = 48.7%*, 4th d = 45.7%*, and 8th d = 42.3%. ATIII levels increased significantly after infusion of this standard dose in all patients, although they have not been fully corrected (Friedman test, * p < 0.02), which has been sustained till the 4th day. There was no improvement on the clinical outcome. CONCLUSIONS: These findings suggest that doses of ATIII concentrate higher than 50 U/kg/infusion must be administered to patients with severe hepatic failure, to guarantee normal levels of the inhibitor, in order to verify its influence on the hemostatic mechanism.

Brazilian experience with two conditioning regimens in patients with multiple sclerosis: BEAM/horse ATG and CY/rabbit ATG.

Studies have shown that autologous hematopoietic SCT (HSCT) can be used as an intensive immunosuppressive therapy to treat refractory patients and to prevent the progression of multiple sclerosis (MS). This is a prospective multicentric Brazilian MS trial comparing two conditioning regimens: BEAM/horse ATG and CY/rabbit ATG. Most (80.4%) of the 41 subjects in the study had the secondary progressive MS subtype and the mean age was 42 years. The baseline EDSS score in 58.5% of the subjects was 6.5 and 78% had a score of 6.0 or higher, respectively. The complication rate during the intra-transplantation period was 56% for all patients: 71.4% of the patients in the BEAM/hATG group and 40% in the CY/rATG group (P=0.04). Three subjects (7.5%) died of cardiac toxicity, sepsis and alveolar hemorrhage, all of them in the BEAM/ATG group. EFS was 58.54% for all patients: 47% in the BEAM/hATG group and 70% in the CY/rATG group (P=0.288). In conclusion, the CY/rATG regimen seems to be associated with similar outcome results, but presented less toxicity when compared with the BEAM/hATG regimen. Long-term follow-up would be required to fully assess the differences in therapeutic effectiveness between the two regimens.

New alternative methods to teach surgical techniques for veterinary medicine students despite the absence of living animals. Is that an academic paradox?

Due to a raised ethical mentality, veterinary schools are pursuing methods to preserve animal corpses used for surgical technique classes in an attempt to reduce the use of living animals for teaching. Generally speaking, animal and human bodies are usually preserved with 10% aqueous formalin solution especially for descriptive anatomy classes. Other possibilities include the use of glycerol, alcohol and phenol. At present, new fixatives have been developed to allow a better and longer preservation of animal corpses in order to maintain organoleptic characteristics, i.e. colour, texture, as close as possible to what students will deal with living animals. From 2004, in our college, surgical technique classes no longer use living animals for students' training. Instead, canine corpses chemically preserved with modified Larssen (MLS) and Laskowski (LS) solutions are preferred. The purpose of this study was to investigate comparatively the biological quality of preservation of these two solutions and to evaluate students' learning and acceptance of this new teaching method. Although these fixatives maintain body flexibility, LS solution failed to keep an ordinary tissue colouration (cadavers were intensely red) and tissue preservation was not adequate. By contrast, MLS solution, however, did not alter the colouration of cadavers which was fairly similar to that normally found in living animals. A remarkable characteristic was a very strong and unpleasant sugary odour in LS-preserved animals and therefore the MLS solution was the elected method to preserve cadavers for surgical technique classes. The students' feedback to the use of Larssen-preserved cadavers was very satisfactory, i.e. 96.6% of students were in favour of the use of cadavers for surgical training and on average 91.8% (2002-2003) of students preferred the MLS solution as the chemical preserver, whereas only 8.2% elected LS solution for teaching purposes. From the students' point of view (95.1%) the ideal class would be an initial training in MLS cadavers followed by classes with animals admitted to the Veterinary Hospital.

Sex-related macrostructural organization of the deer's brachial plexus.

We describe the morphological organization of the deer brachial plexus in order to supply data to veterinary neuroclinics and anaesthesiology. The deer (Mazama gouazoubira) brachial plexus is composed of four roots: three cervical (C6, C7 and C8) and one thoracic (T1). Within each sex group, no variations are observed between the left and the right brachial plexus, though sex-related differences are seen especially in its origin. The origin of axillary and radial nerves was: C6, C7, C8 and T1 in males and C8-T1 (radial nerve) and C7, C8 and T1 (axillary nerve) in females; musculocutaneous nerve was: C6-C7 (males) and C8-T1 (females); median and ulnar nerves was: C8-T1 (males) and T1 (females); long thoracic nerve was: C7 (males) and T1 (females); lateral thoracic nerve was: C6, C7, C8 and T1 (males) and T1 (females); thoracodorsal nerve was: C6, C7, C8 and T1 (males) and C8-T1 (females); suprascapular nerve was: C6-C7 (males) and C6 (females) and subscapular nerve was: C6-C7 (males) and C7 (females). This study suggests that in male deer the origin of the brachial plexus is more cranial than in females and the origin of the brachial plexus is slightly more complex in males, i.e. there is an additional number of roots (from one to three). This sexual dimorphism may be related to specific biomechanical functions of the thoracic limb and electrophysiological studies may be needed to shed light on this morphological feature.

Proton magnetic resonance relaxation studies on the structure of mixed micelles of Triton X-100 and dimyristoylphosphatidylcholine.

Proton magnetic resonance and gel chromatographic studies on mixtures of phospholipid and the nonionic surfactant Triton X-200 have shown that at temperatures above the thermotropic phase transition of the phospholipid and below the cloud point of Triton, mixed micelles are present at molar ratios above about 2:1 Triton/phospholipid. Proton T1 and T2 (from line widths) relaxation times are reported for protons in Triton micelles and in mixed micelles of Triton and dimyristoylphosphatidylcholine at a molar ratio of 3:1 Triton/phospholipid. The T1 values and their temperature dependence and the activation energies of the various Triton proton groups appear to reflect internal motions of the Triton molecules in the micelle. Measurements of the T1/T2 ratio and frequency dependence (55-220 MHz) suggest that the hydrophobic tert-butyl group in Triton is observed under extreme narrowing conditions. The T1 and T2 values of Triton are unchanged in the presence of phosphatidylcholine. The T1 values of various protons of dimyristoylphosphatidylcholine in mixed micelles are similar to those reported for the phospholipid in sonicated vesicles, which are used as membrane models, and presumably the same coupled trans-gauche motions dominate. The T2 values for the terminal methyl and choline methyl protons in the phospholipid are longer than those reported for these groups in vesicles. Hence, the motion of the phospholipid in the mixed micelles appears to be less restricted than in vesicles. T1 measurements in H20/D20 mixtures are consistent with the idea that water does not penetrate the hydrophobic core of the mixed micelles, while water does solvate the polar oxyethylene and choline methyl groups. Titration with Mn2+ confirms that the oxyethylene and choline methyl groups are on the exterior of the mixed micelle while the hydrophobic groups are located in the micellar interior.