Autoreactive T cells target peripheral nerves in Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is a rare heterogenous disorder of the peripheral nervous system, which is usually triggered by a preceding infection, and causes a potentially life-threatening progressive muscle weakness1. Although GBS is considered an autoimmune disease, the mechanisms that underlie its distinct clinical subtypes remain largely unknown. Here, by combining in vitro T cell screening, single-cell RNA sequencing and T cell receptor (TCR) sequencing, we identify autoreactive memory CD4+ cells, that show a cytotoxic T helper 1 (TH1)-like phenotype, and rare CD8+ T cells that target myelin antigens of the peripheral nerves in patients with the demyelinating disease variant. We characterized more than 1,000 autoreactive single T cell clones, which revealed a polyclonal TCR repertoire, short CDR3β lengths, preferential HLA-DR restrictions and recognition of immunodominant epitopes. We found that autoreactive TCRβ clonotypes were expanded in the blood of the same patient at distinct disease stages and, notably, that they were shared in the blood and the cerebrospinal fluid across different patients with GBS, but not in control individuals. Finally, we identified myelin-reactive T cells in the nerve biopsy from one patient, which indicates that these cells contribute directly to disease pathophysiology. Collectively, our data provide clear evidence of autoreactive T cell immunity in a subset of patients with GBS, and open new perspectives in the field of inflammatory peripheral neuropathies, with potential impact for biomedical applications.

Camps for Children with Diabetes: A Philosophy and its Application

The establishment of residential summer camps for children with dia betes has filled multiple needs: recrea tional, educational, and social. Provid ing a safe, fun, and productive sum mer program is the subject of this paper, with a focus on experiences ac cumulated over 25 years at one pro gram in Texas. Successful diabetes camps are forged from solid beliefs about diabetes management, high expectations, and qualifications of the medical staff, thoughtful and reasoned considerations of the purposes for camp, and the incorporation of know ledge about diabetes into quality, well- child care.

14 EPIGENETIC CHANGES IN EQUINE SPERMATOZOA DURING CRYOPRESERVATION: A PRELIMINARY STUDY

The use of cryopreserved semen for insemination of mares facilitates breeding management but often results in reduced conception rates. This has been mainly attributed to changes in sperm membrane function caused by the freezing-thawing procedure. However, semen processing may also contribute to epigenetic changes in spermatozoa. In the present study, we therefore addressed changes in sperm DNA-methylation induced by cryopreservation of stallion semen. We hypothesised that the cryoprotectant may influence the DNA-methylation level of frozen-thawed semen. For this purpose, semen was collected from fertile Shetland pony stallions. Global DNA-methylation was assessed by ELISA (5-mC DNA ELISA Kit, Zymo Research, Irvine, CA, USA) with a monoclonal antibody sensitive and specific for 5-methylcytosin after DNA extraction and denaturation (100 ng of DNA per sample). The level of 5-methylcytosin in DNA is reported as the amount of methylated cytosine relative to the cytosine genomic content (%). Statistical analysis was done with the SPSS Statistics 21 software. Values are means ± standard error of the mean. In Experiment 1, 1.5 mL of raw semen (n = 6 stallions, 1 ejaculate each) was shock-frozen at –196°C for 15 min and thawed at 38°C for 60 s. Semen motility and membrane integrity were completely absent, while DNA-methylation was similar in raw (0.4 ± 0.2%) and shock-frozen (0.3 ± 0.1%) semen (not significant). In Experiment 2, 3 ejaculates per stallion (n = 6) were included. Semen quality and DNA-methylation was assessed before addition of the freezing extender and after freezing-thawing with either Ghent (Minitube, Tiefenbach, Germany; cryoprotectant: 5% glycerol) or BotuCrio (Nidacon, Mölndal, Sweden; cryoprotectants: 1% glycerol and 4% methylformamid) extender. Semen was frozen in 0.5-mL straws in a computer-controlled rate freezer (IceCube 14 M; Sylab, Purkersdorf, Austria, cooling rates: 20°C to 5°C: 0.3°C min–1, 5°C to 25°C: 10°C min–1, –25°C to –140°C: 25°C min–1). Semen motility, morphology, and membrane integrity were significantly reduced (e.g. total motility before freezing: 88.8 ± 1.4%) by cryopreservation but not influenced by the extender used (e.g. total motility: Ghent 69.5 ± 2.0, BotuCrio 68.4 ± 2.2%; P < 0.001 v. nonfrozen semen). Cryopreservation significantly (P < 0.01) increased the level of DNA-methylation (before freezing: 0.6 ± 0.1%, Ghent 6.4 ± 3.7, BotuCrio 4.4 ± 1.5%; P < 0.01), but no differences between the freezing extenders were seen. The level of DNA-methylation was not correlated with semen motility, morphology, or membrane integrity. The results demonstrate that semen processing for cryopreservation increases the DNA-methylation level in stallion semen. In the present study, this effect occurred irrespective of the cryoprotectant but was not seen after shock-freezing in the absence of cryoprotectants. The reduced fertility of mares after insemination with frozen-thawed semen may at least in part be explained by methylation of sperm DNA, which occurs in response to the cryopreservation procedure.

[Births and children after assisted reproductive technologies. A retrospective analysis with special regard to multiple pregnancies at the Department of Obstetrics and Gynecology, Paracelsus Medical University Salzburg (2000-2009) with an extrapolation for Austria]

BACKGROUND

Austria still lacks a baby-take-home rate after assisted reproductive technologies (ART) and therefore an adequate quality management of ART.

PATIENTS AND METHODS

This paper extrapolates data about births/infants after ART at the University Clinic of Obstetrics and Gynaecology (PMU/SALK) in Salzburg for Austria, especially in regard to multiple births/infants collected between 2000 and 2009.

RESULTS

On average 2 271 infants were born per year during the last 10 years. Among them, 76 infants (3.34% of all children) were born after ART. Of all children conceived by ART and born (759) at the University Clinic of Obstetrics and Gynaecology 368 are multiples. This is 48.5% of all children born after ART. 31.6% of all multiples born were conceived through ART.

DISCUSSION

The extrapolation of data concerning multiples results in 1 255 multiples/year after ART for Austria.

CONCLUSION

Without a baby-take-home rate, serious quality management of reproductive medicine is impossible. Online registration of deliveries and infants is the only adequate approach. The data of this statistical extrapolation from a single perinatal center not only provide a survey about the situation in Austria, but also support the claim of a quantitative (numbers) as well as qualitative (condition of infants) baby-take-home rate after ART.

Transient outward potassium current in rabbit atrium is depressed after short-time rapid atrial pacing but recovers after a longer pacing period

In rabbit, after short-time rapid atrial pacing (RAP), atrial ion currents are reduced similarly as in human chronic atrial fibrillation (AF). Using the rabbit model, time-course of transient outward potassium current (I(to)) remodeling due to RAP was studied. RAP (600 bpm) was applied via an atrial lead for 0 (control), 24 and 120 h, n = 4 animals/group. Using patch clamp technique in whole-cell mode, current densities and biophysical properties were measured in isolated atrial myocytes. After 24 h of RAP, a reduction of peak I(to) (mean +/- SEM, test potential +50 mV, +37 degrees C) was observed (60.3 +/- 5.4 pA/pF (control, n = 20) vs. 28.0 +/- 2.5 pA/pF (24 h, n = 21)). Inactivation of I(to) was slower after 24 h, other biophysical properties were unaltered. However, I(to) recovered after 120 h: 51.7 +/- 4.5 pA/pF (n = 26, p = n.s. vs. control). Inactivation tended to also recover to initial values but was still different to control. Early I(to) remodeling due to RAP in rabbits seems to be more complex than previously thought: a time course of I(to) remodeling with swayings has to be considered when using the rabbit model of RAP in order to study early remodeling or rather its therapeutic manipulation.

Blockade von Adhäsionsmolekülen mit Natalizumab in der Therapie der Multiplen Sklerose

Natalizumab is a humanized, monoclonal antibody, that inhibits adhesion molecules (alpha(4)-integrins) on the surface of immune cells. These adhesion molecules are important for binding of lymphocytes to endothelial cells of blood vessels and infiltration of inflammatory cells into tissues. Natalizumab is currently being tested in large clinical trials for the treatment of multiple sclerosis (MS) and other autoimmune diseases (inflammatory bowel diseases, rheumatoid arthritis). After demonstrating the safety and potential effectiveness of natalizumab in MS therapy during shorter treatment periods (</=6 months) in clinical phase I and II studies, two ongoing large, double-blinded, placebo-controlled phase III trials (named AFFIRM and SENTINEL) are evaluating its efficacy for patients with relapsing-remitting MS in respect to primary clinical endpoints (relapse rate, disease progression). Based a 1-year interim analysis of these studies, natalizumab was recently authorized by the U.S. Food and Drug Administration for treatment in reducing the frequency of clinical surges in multiple sclerosis, and an application was also made for its use in Europe. After more than 2 years of combined natalizumab (Tysabri) and interferon beta-1a (Avonex) therapy in the so-called Sentinel Study, there was one unexpected death and one appearance of progressive multifocal leukoencephalopathy. As a result, in February 2005 the manufacturers (Biogen/Elan) stopped all running studies of natalizumab and removed the drug from the market. New studies are underway to gain more understanding and especially to determine the risk to patients treated in the Sentinel Study. This article summarizes and updates the results of previous and ongoing natalizumab trials in the context of MS.

The sex determination in Ellobius lutescens remains bizarre

Mammalian sex determination and gonad differentiation are the result of a complex interaction of fine-tuned spatial and temporal gene expression with threshold levels of individual genes. The male pathway is initiated by SRY. Some exceptional mammals determine male sex without the SRY gene and even without a Y chromosome. Ellobius lutescens in this report is one example of this "weird" species. We provide key data on the genomic level that there are no coarse differences in the genomes of male and female animals by comparative genomic hybridization. On the gene level we studied the gene Nr5a1 for the orphan nuclear receptor, steroidogenic factor SF-1, a central constituent for gonad differentiation and adrenal gland development. The Ellobius lutescens Nr5a1 gene was mapped to the proximal short arm of chromosome 2 by fluorescence in situ hybridization. In addition, we provide evidence by linkage analysis in two E. lutescens pedigrees that Nr5a1 is not the key male sex-determining gene in Ellobius lutescens.

Mechanisms of Staphylococcus aureus induced apoptosis of human endothelial cells

Staphylococcus aureus plays an important role in sepsis, pneumonia and wound infections. Here, we demonstrate that infection with several S. aureus strains results in apoptosis of human endothelial cells. S. aureus induced an activation of cellular caspases, the acid sphingomyelinase, a release of cytochrome c and a stimulation of Jun NH2-terminal kinase (JNK). The significance of these findings is indicated by a prevention of S. aureus triggered apoptosis of human cells deficient for ASM or upon genetic or pharmacological inhibition of JNK or caspases, respectively.

Type 2 diabetes in children and adolescents: an emerging disease

The incidence of type 2 diabetes is increasing in the United States, and minority populations in particular seem to be affected. In the past, it was thought that type 2 diabetes occurred only in adults. However, an alarming epidemic has emerged, and children as young as 8 years of age are now being diagnosed with the disease. The purpose of this article is to present pediatric nurse practitioners with the most recent information about type 2 diabetes in children and adolescents, summarize current understanding about diagnosis, and outline treatment options.

Mini-dose glucagon rescue for hypoglycemia in children with type 1 diabetes

OBJECTIVE

Children with type 1 diabetes are frequently difficult to manage during times of gastroenteritis or poor oral intake of carbohydrates because of mild or impending hypoglycemia. The present study describes the effective use of small doses of subcutaneous glucagon in these children.

RESEARCH DESIGN AND METHODS

We analyzed 33 episodes of impending or mild hypoglycemia in 28 children (ages 6.6 +/- 0.7 years). All were healthy except for type 1 diabetes and an episode of gastroenteritis. Using a standard U-100 insulin syringe, children ages < or = 2 years received two "units" (20 microg) of glucagon subcutaneously and those ages >2 years received one unit/year of age up to 15 units (150 microg). If the blood glucose did not increase within 30 min, the initial dosage was doubled and given at that time. We used patients' self-glucose monitoring devices, aqueous glucagon, standard insulin syringes, and frequent phone contact with a physician and/or a diabetes nurse educator in this study.

RESULTS

Blood glucose was 3.44 +/- 0.15 mmol/l before and 8.11 +/- 0.72 mmol/l 30 min after glucagon. In 14 children, relative hypoglycemia recurred, requiring retreatment (3.48 +/- 0.18 to 6.94 +/- 0.72 mmol/l). In four children, a third dose was required. The glucagon was well tolerated In 28 of the 33 episodes of impending hypoglycemia, the children remained at home and fully recovered. Five children were taken to their local hospital because of concerns of dehydration or fever, but none for hypoglycemia.

CONCLUSIONS

Mini-dose glucagon rescue, using subcutaneous injections, is effective in managing children with type 1 diabetes during episodes of impending hypoglycemia due to gastroenteritis or poor oral intake of carbohydrate.

Spectral karyotyping of mouse cell line WMP2

We have evaluated the mouse cell line WMP2 using both GTG-banding analysis and spectral karyotyping to verify the reliability of using this established cell line derived from WMP/WMP mice. The WMP cell lines contain easily identifiable metacentric fusion chromosomes and are used extensively for gene mapping. Because of karyotypical changes in the WMP1 cell line, WMP2 was examined. Our results demonstrate that WMP2 is stable during culture, and the karyotype is simple and easy to use. Based on the findings discussed in this paper, we recommend the use of the WMP2 cell line for future prospective gene mapping in the mouse.

Feminization as a critical component of the changing hydrosocial contract

The Dublin Principles recognize the role that women play in water resources management. The South African Minister of Water Affairs, Prof. Kader Asmal, coined a new expression by referring to the "feminization of water". The article explores some of the ramifications of this and shows that the two aspects are not necessarily the same thing. Feminization does not necessarily mean bringing more women into management processes as it is often depicted. This is the quantitative aspect that is often referred to by male managers and it has been given a negative implication as a result. The more important issue is the qualitative aspect that involves processes such as stakeholder participation, viewing alternatives before a decision is made and accountability.

Comparing outpatient and inpatient diabetes education for newly diagnosed pediatric patients

PURPOSE

The purpose of this study was to compare the efficacy of outpatient vs inpatient programs on medical, cognitive, behavioral, and psychosocial outcomes.

METHODS

Using three large, tertiary medical centers in the United States, the sample of 32 children newly diagnosed with diabetes and their parents were recruited. Children and parents who received outpatient education were compared with those who received inpatient education. The following outcome variables were compared: (1) rates of hospital readmissions and/or emergency room visits for either severe hypoglycemia or ketoacidosis, (2) knowledge, (3) sharing of responsibilities, (4) adherence, (5) family functioning, (6) coping, and (7) quality of life.

RESULTS

In general, no statistically significant differences were found between the groups. A trend was noted in the outpatient group with regard to improved use of emergency precautions on the adherence measure, roles on the family functioning measure, maintaining family integration on the parental coping measure, and disposition on the children's coping instrument.

CONCLUSIONS

Findings support the safety and efficacy of the outpatient program method.

Nutrition in pediatric primary care: assessment and common problems

As health promotion and disease prevention gain prominence, nutritional assessment and intervention become important tools for the NP. The nutritional needs of the growing child and adolescent are explored, with a discussion about common nutritional deficits seen in the pediatric population.

Reliability and validity of the Diabetes Family Behavior Scale (DFBS)

The Diabetes Family Behavior Scale (DFBS) was designed to measure diabetes-specific family support. The purposes of this study were to refine the scale and to assess reliability and criterion validity in terms of relationship to metabolic control. The DFBS was administered to 321 children and adolescents with insulin-dependent diabetes mellitus (IDDM). Blood was drawn for determination of glycosylated hemoglobin (HbA1c). Based on an item-analysis procedure, the DFBS was revised to include 47 items with two subscales, one to reflect guidance-control and one to reflect warmth-caring. Acceptable internal consistency was found for the DFBS total score (.86), and for the guidance-control (.81) and warmth-caring (.79) subscales. There was a statistically significant relationship in the expected direction between DFBS total score and HbA1c (r = -.12, P < .03), and between the guidance-control subscale and HbA1c (r = -.17, P < .002).

Teaching assertive communication skills to adolescents with diabetes: evaluation of a camp curriculum

Diabetes management requires consistently implementing adherence behaviors in a variety of settings. For some adolescents, consistency may be difficult due to problems in communication and assertiveness. The purpose of the present study was to evaluate the impact of a camp curriculum to teach assertive communication skills to adolescents with diabetes. The curriculum included didactic information, sharing of personal experiences, and role playing. Results showed a significant increase in adolescents' perceptions of their assertiveness from before to after the camp experience, an increase that was still apparent at a 3-month follow-up. No changes were reported in parental perceptions of their adolescents' degree of openness in communicating or in communication problems. In contrast, adolescents reported a significant decrease in their degree of openness in communicating with fathers, with a similar trend for mothers. These results suggest that the curriculum was successful in meeting the primary goal of enhancing the adolescents' assertive communication skills but had a questionable impact on their general communications with parents.

The status of nursing administrators in Hungary

The College for Health Workers was established in 1973 in Hungary with the aim to educate and train highly qualified healthcare workers to meet all the demands of special health care. Although matrons (nursing administrators) who have graduated from the College are capable of performing special tasks to ensure quality care, they do not have the corresponding authority and recognition. Below, how nurse researchers in Hungary proved this hypothesis.

[Ogilvie syndrome as a complication following extensive total abdominal hysterectomy]

Acute pseudoobstruction of the colon (Ogilvie syndrome) is a rare entity observed postoperatively or in association with various medical conditions. Appropriate therapy avoids the life-threatening complication of cecal perforation with its attendant high mortality rate of over 40%. Today colonoscopic decompression is the treatment of choice.

[Thrombolytic therapy and balloon dilatation. The effect on infarct time, reperfusion and reocclusion]

127 patients, admitted within six hours of onset of symptoms of acute transmural myocardial infarction, received at first 250 000 U streptokinase intravenously over 20 min, followed by an intracoronary infusion of 250 000 U after coronary angiographic demonstration of the infarct vessel. Those in whom the infarct vessel was closed were randomized into two groups. An attempt at recanalization was made either by thrombolysis alone, through a specially developed 3F catheter (group I, 64 patients), or by thrombolysis and dilatation with 4F Grüntzig balloon catheter (group II, 63 patients). There was no significant difference between the two groups with regard to sex, age, infarct site, creatine-kinase level and interval between onset of symptoms and treatment. Re-perfusion rate for group I was 92% (59 patients), for group II 89% (56 patients). Re-occlusion during the hospital stay occurred in 10 of 59 patients in group I, in 9 of 55 in group II. Re-occlusion occurred in only 8% (3 patients) after successful dilatation, but in 35% (6 patients) after failed dilatation. In the subsequent six months further occlusions were observed in seven group I and two group II patients. Combined drug-mechanical recanalization thus increased the re-perfusion rate, shortened the infarction time and made possible full revascularization by subsequent dilatation which led to a reduction in the re-occlusion rate.

Coexisting idiopathic hypertrophic subaortic stenosis and coronary artery disease. Clinical implication and operative management

Patients with either coronary artery disease (CAD) or idiopathic hypertrophic subaortic stenosis (IHSS) may have angina as a dominant symptom. It is also possible that these two diseases may coexist in the same patient. Such an association has been reported in 25% of patients with IHSS who are over 45 years of age. It is important that both entities be looked for in the evaluation of the patient with angina, particularly when operative management is contemplated. Treatment of one and not the other may leave the patient symptomatic. We have encountered three patients with both CAD and severe IHSS and have managed each with septal myectomy and coronary artery revascularization. Each has obtained significant symptomatic improvement.

Vasography in rats

Vasovasostomy was performed in 20 rats. Vasography then was used to determine the patency of the vas. The scrotum was entered through a longitudinal incision and the scrotal contents were extruded extravaginally. The vas was divided near the epididymis and a 0.4/0.7-mm cannula was inserted into the abdominal end of the vas and contrast medium was injected under fluoroscopic control. The results were documented by radiography. It is concluded that vasography is a reliable method for assessing the success of vasovasostomy in rats.

Intramuscular urography in rats

In addition to macroscopic studies, microscopic studies, and biologic tests, urography is a valuable method for investigating renal function in rats. Intravenous urography is complicated, however, by the difficulty of puncturing a tail vein or the femoral vein. Intramuscular urography, on the other hand, is a simple and reliable method for radiographic examination of the kidneys and ureters, and gives information on morphology as well as physiology. In this study in 40 rats, intramuscular urography was performed under general anesthesia, and the contrast medium was injected into the gluteal muscles. Dense nephrograms and optimum films of the calices and the ureters were obtained approximately 40 minutes after injection.

Iron excretion from the goblet cells of the small intestine in man. An additional regulatory mechanism in iron homeostasis?

Iron-excreting goblet cells were observed by chance in a patient with myelogenic leukaemia. Duodenal and jejunal biopsies from patients with a wide spectrum of disorders have therefore been examined retrospectively after staining with Perl's iron method. Thirty-seven of the patients had iron-excreting goblet cells. The presence of iron has been confirmed by X-ray microanalysis and by electron microscopic histochemistry. In addition to iron-excreting goblet cells, most of these patients had iron-containing macrophages in lamina propria. This may indicate that the two types of cells co-operate in the excretion process. It is suggested that iron excretion may be part of the common iron balance mechanism.

Influence of cholesterol/fat feeding on cholesterol esterification and morphological structures in intestinal mucosa from guinea pigs

Guinea pigs were fed a semisynthetic diet containing 10% (by weight) cottonseed oil and 1% cholesterol. In response to cholesterol/fat feeding there was an increase in both the unesterified cholesterol (UC) and cholesteryl ester (CE) of the intestinal mucosal cell. Along with the increased cholesterol levels there was a 4-fold increase in the microsomal acylCoA:cholesterol acyltransferase (ACAT) activity after only two days of cholesterol/fat feeding. After 6 days on the experimental diet the ACAT activity was up to 8-fold the activity of the control, and then remained at this level for up to 20 days. The increased ACAT activity was probably not due to increased substrate concentration alone, since the fractional esterification of cholesterol also increased when the cholesterol/fat containing diet was given. There was also an increase in the triglyceride content of the intestinal mucosal cells from guinea pigs on the experimental diet. The mucosal cells of the cholesterol/fat fed animals accumulated varying amounts of lipid droplets, which were without an enveloping membrane, suggesting that the uptake of lipids from the intestinal lumen was higher than the capacity to synthesize and/or secrete lipoproteins. Simultaneously the size and amount of secondary lysosomes increased. A considerable increase in lipid droplets, lipolysosomes, and residual bodies was observed in the lamina propria macrophages while no crystalline clefts were seen.

[Experiences with the condition of resection of the hip joint following removal of the alloarthroplastic implantate (author's transl)]

30 patients whose total endoprosthesis of the hip joint had been removed without any replacement, thus creating a so-called state of secondary resection, were followed up 6 months to 6 years after the operation. It was found that in almost two-thirds of the cases a subjective feeling of improved mobility was reported. The objective findings consisted in restrictions of the total rotation, abduction and adduction of 1/3 rd of the normal extent of mobility. An average value of 74.7 degrees was recorded for flexion. 28 patients stated that their walking performance was satisfactory to very good when using a walking-stick as support. More than three-quarters of the patients questioned stated their pain had been positively influenced by the creation of the state of secondary resection. Another objective finding was a difference between the length of the legs amounting to 4.2 cm on the average. We could prove the existence of a relationship between the difference in leg length and the roentgenologically visualised supporting of the resection area of the coxal end of the femur at the lateral pelvis. Since all the patients with the exception of two could resume their customary daily routine activities, the state of secondary resection after unsuccessful total endoprosthesis of the hip joint must be considered a reasonably acceptable alternative.

Influence of 4-aminopyrazolopyrimidine on morphology, synthesis of triglyceride and protein and their secretion in rat hepatocytes

The influence of 4-aminopyrazolopyrimidine (4-APP) on morphology and on synthesis and secretion ability of isolated rat hepatocytes was investigated: 4-APP was found to inhibit both the synthesis and secretion of proteins. The synthesis of triglycerides was unaffected by 4-APP, while the secretion of triglycerides was markedly reduced. Transmission electron microscopy revealed that 4-APP induced morphological changes in the smooth membrane systems, the smooth endoplasmic reticulum and the Golgi apparatus. The possibility that 4-APP inhibits lipoprotein formation by inhibition of the apoprotein synthesis is discussed.

The effect of D-galactosamine on LCAT secretion and ultrastructure of isolated rat hepatocytes

The effect of D-galactosamine on secretory activity and morphology of isolated rat hepatocytes was investigated: Galactosamine was found to reduce the secretion of lipoproteins (as indicated by the release of free cholesterol and triacylglycerol) as well as the secretion of lecithin: cholesterol acyltransferase (LCAT) and [14C]-labelled proteins from the isolated cells. The secretion of LCAT was inhibited much more than that of the other secretory products studied. Transmission electron microscopy revealed that galactosamine induced morphological changes in RER, mitochondria and nucleoli. The most striking feature of galactosamine-treated hepatocytes, however, was the appearance of swollen lysosomes. Some of these organelles measured up to 3 mumicrometer in diameter. Uridine did not abolish the effect of galactoosamine upon the secretory activity of hepatocytes. The most conspicuous ultrastructural feature in cells that had been incubated with both uridine and galactosamine was the appearance of large amounts of glycogen. The possibility that galactosamine inhibits glycogenolysis is discussed. The rather selective effect of galactosamine on LCAT secretion suggests the use of this compound for the study of the interrelationship between LCAT and lipoprotein secretion.

Familial mitral valve prolapse and myotonic dystrophy

When a patient with mitral valve prolapse was found to have myotonic dystrophy, his family was studied to ascertain the occurrence of these abnormalities. Of 25 relatives screened, 8 had evidence of both myotonic dystrophy and mitral valve prolapse and 2 had evidence of myotonic dystrophy alone. Thirteen patients had evidence of neither condition and 1 had mitral valve prolapse alone. The association of these two conditions within a family has not previously been observed and valvular heart disease has not been recognized in myotonic dystrophy. This association should be looked for in other patients.

Complete correction of double-outlet right ventricle with situs inversus, 1-loop, and 1-malposition (I,L,L) with subaortic VSD and pulmonary stenosis

The repair a unique case of double-outlet right ventricle is reported. This case illustrates the increasingly difficult problem of developing an appropriate nomenclature in complex congenital heart disease. A classification of double-outlet right ventricle based upon Van Praagh's symbolic terminology is suggested.

Measurement of thickness within sections by quantitative electron microscopy

To apply the method of quantitative electron microscopy to the measurement of mass in thin sections, the thickness of the section at or very near the structure to be studied must be known. Dowex anion exchange resin AG 1 x 2, stained with phosphotungstic acid (PTA) at pH 6.4, was used as a thickness standard which could be embedded and sectioned. The sectioned PTA-Dowex appeared uniformly stained and exhibited suitable electron opacity. The stoichiometry of the reaction between PTA and the Dowex resin was measured by three independent methods based on gravimetric, colorimetric, and nitrogen determinations whose results showed close agreement. From the PTA uptake, the density of the stained spheres was calculated. Mass of a defined area of PTA-Dowex was measured by quantitative electron microscopy, and from this mass and density, the volume and then the thickness were calculated. The values for thickness were compared to those obtained by interference microscopy on the embedding medium alone in the same sections.