Local Active Suppression by Suppressor Cells in the Decidua: A Review

ABSTRACT: The immunological survival of the antigen-bearing mammalian feto-placental unit is determined by the functional properties of the tissues at the feto-maternal interface. Antigen-specific systemic suppressor mechanisms such as suppressor T cells and non-antigen-specific suppressive serum factors appear not to play a major role in protection of the fetus. A novel type of non-MHC specific suppressor cell accumulates locally in the decidua of successfully allopregnant mice. This decidua-associated suppressor is a small lymphocytic cell possessing cytoplasmic granules, lacks T cell markers, and is deficient in number and activity at the implantation sites of viable xenogeneic Mus caroli embryos gestating in the uterus of Mus musculus animals at the time that maternal lymphoid cells begin to infiltrate the xenoembryos. These Mus caroli embryos subsequently resorb. Further experimental studies suggest that the trophoblast cells associated with successful pregnancy recruit bone-marrow derived maternal non-T suppressor cells to the decidua and thus, by an indirect mechanism, may act to protect the fetus from effector cells of the mother's immune system.     

INTRAEPITHELIAL LYMPHOCYTE COUNTS IN SMALL INTESTINAL BIOPSIES FROM CHILDREN WITH DIARRHOEA

Abstract. We have investigated small intestinal biopsies from children with coeliac disease, acute gastroenteritis, failure to thrive and giardiasis, to find out if a high intraepithelial lymphocyte count is a feature specific to coeliac disease, or whether it is always associated with partial or subtotal villous atrophy. The results indicate that the normal range for childrens' intraepithelial lymphocyte counts is similar to that for adults (around 6–40 lymphocytes per 100 epithelial cells); that counts are high in coeliac disease, but also in some children with giardiasis or with failure to thrive in whom the jejunal biopsy appears otherwise normal; and that intraepithelial lymphocyte counts are normal in acute gastroenteritis even when there is partial villous atrophy with increased lamina propria lymphoid cell infiltrate. Thus, this measurement of small intestinal lymphocyte infiltration may be of diagnostic value in differentiating the diarrhoea of food intolerance from infectious diarrhoeas in young children.     

PSEUDOHYPOALDOSTERONISM Clinical, Biochemical and Morphological Studies in a Long-term Follow-up

ABSTRACT. A boy with pseudohypoaldosteronism was followed from birth to the age of 7 years. Failure to thrive, vomiting, dehydration, hyponatraemia and urinary sodium loss were prominent findings. Urinary excretion of corticosteroid metabolites was normal. Before treatment, excessively high plasma renin concentration was found, associated with a marked activation of aldosterone secretion. A renal biopsy showed pronounced hypertrophy of the juxtaglomerular apparatus. Persisting metabolic acidosis and an insufficient urinary acidifying capacity suggested the presence of distal renal tubular acidosis. Treatment with sodium bicarbonate and sodium chloride from 19 to 31 months of age resulted in normal growth and normal physical and mental development. The plasma electrolytes were normalized but a pronounced activation of the renin–aldosterone system persisted after therapy, and on sodium restriction this system responded with a considerable further activation.     

Practices and Policies in the Initiation of Breastfeeding

Despite increasing knowledge about factors affecting the initiation of breastfeeding, many mothers still encounter problems and discontinue breastfeeding earlier than desired. Many hospitals still have not implemented the practices that are known to be helpful in the establishment of breastfeeding. As a result, a study was conducted to examine the policies and practices affecting breastfeeding in hospitals in Alberta, Canada. A questionnaire-based survey of all Alberta hospitals (including directors of nursing and staff nurses) found that many practices were still relatively inflexible; did not always reflect accurate, research-based information; and were not geared to the needs of mothers and infants. The implications of these findings are discussed.     

Normal range of fetal transcutaneous carbon dioxide tension during labour

Summary. Fetal transcutaneous carbon dioxide tension (tc-Pco), was monitored during 122 deliveries, using an electrode temperature of 44°C in 80 cases and of 41°C in 42 cases. Significant correlations between tc- P co₂ and umbilical artery blood P co₂ were found using both electrode temperatures, but the regression lines indicated a larger and more inconstant CO₂-contribution from skin metabolism when the low electrode temperature was used. Normal range of tc- P co₂ was calculated at 41°C and 44°C electrode temperatures. Mean values of fetal tc- P co₂ were found to increase during normal labour, and especially in fetuses developing acidosis, but only four of six infants born with acidaemia had tc- P co₂ values exceeding the normal range.     

Placental transfer of bupivacaine, pethidine and lignocaine in the rabbit. Effect of umbilical flow rate and protein content

Summary. The factors determining the placental transfer of drugs used in labour were studied in the rabbit placenta perfused in situ with Krebs bicarbonate buffer. During concurrent maternal intravenous infusion of bupivacaine, lignocaine, pethidine and antipyrine, drug concentrations were measured in maternal arterial plasma and placental effluent perfusate, the flow rate and protein content of which were varied. Protein binding and content were also measured. Placental clearance of antipyrine, which is unbound, was unaltered by perfusate protein content, and increased with umbilical perfusate flow up to 2 ml/min. Clearance of lignocaine and pethidine, which were 20–30% protein bound, increased to a small extent with perfusate protein, and were flow-dependent up to the maximum perfusate flow of 4 ml/min. Clearances of bupivacaine, which was > 80% bound, increased markedly with perfusate protein but, though flow-dependent, was one-tenth to one-fifth that of the other drugs. Fetal binding and glycoprotein content were less than maternal, hence the equilibrium fetal: maternal ratio is predictably lower for the highly bound bupivacaine than for lignocaine or pethidine. Measured fetal: maternal ratios of bupivacaine were, however, only one-half to one-third of the predicted equilibrium values, suggesting that bupivacaine does not unbind readily in a single transit through the rabbit placenta. Thus, though bupivacaine crosses the placenta more slowly than thc other drugs, the fetal dose of all these drugs will be greatest in healthy babies with good placental blood flows and high plasma proteins.     

Phagolysosomal pH and Location of Particles in Alveolar Macrophages

Phagolysosomal pH and Location of Particles in Alveolar Macrophages.NYBERG, K., JOHANSSON, U., JOHANSSON, A., AND CAMNER, P. (1991).Fundam. Appl. Toxicol. 16, 393–400. Fluorescein-labeledsilica particles (FSP) were instilled into the tracheae of rabbits.Groups of four rabbits were killed after 24 hr, 1 week, 1 month,or 3 months and their lungs were lavaged. Phagolysosomal pHin the alveolar macrophages (AM) was measured using microscopefluorometry with FSP as a probe. Due to the marked decline ofthe fluorescence intensities from the FSP between 1 and 3 monthsafter instillation, it was not possible to measure pH at 3 months,but the values from 24 hr, 1 week, and 1 month were quite similar,with group means of 4.8 and 4.9, respectively. PhagolysosomalpH in AM which phagocytized the FSP in vitro showed values abouthalf a pH unit higher. AM from rabbits lavaged at 1 week hadmore lysosomes in contact with the FSP-containing phagolysosomesand a higher degree of vacuolization between the FSP and thephagolysosomal membrane than AM lavaged at 1 day. The locationof the FSP in the AM appeared to be similar in rabbits lavagedafter 1 week and 3 months. In histologic sections from the lungsthe large majority of the FSP were within cells at all timepoints.     

Reliability and Validity of the Child and Adolescent Trial for Cardiovascular Health (CATCH) Food Checklist: A Self-report Instrument to Measure Fat and Sodium Intake by Middle School Students

OBJECTIVE: To develop a scoring algorithm and evaluate the reliability and validity of scores from the Child and Adolescent Trial for Cardiovascular Health (CATCH) Food Checklist (CFC) as measures of total fat, saturated fat, and sodium intake in middle school students. DESIGN: Randomized, controlled trial in which participants were assigned to 1 of 3 study protocols that varied the order of CFC and 24-hour dietary recall administration. Criterion outcomes were percent energy from total fat, percent energy from saturated fat, and sodium intake in milligrams. SUBJECTS/SETTING: A multiethnic sample (33% ethnic and racial minorities) of 365 seventh-grade students from 8 schools in 4 states. STATISTICAL ANALYSES: Multivariable regression models were used to calibrate the effects of individual food checklist items; bootstrap estimates were used for cross-validation; and kappa statistics, Pearson correlations, t tests, and effect sizes were employed to assess reliability and validity. RESULTS: The median same-day test-retest reliability kappa for the 40 individual CFC food items was 0.85. With respect to item validity, the median kappa statistic comparing student choices to those identified by staff dietitians was 0.54. Test-retest reliability coefficients ranged from 0.84 to 0.89 for CFC total nutrient scores. Correlations between CFC scores and 24-hour recall values were 0.36 for total fat, 0.36 for saturated fat, and 0.34 for sodium; CFC scores were consistent with hypothesized gender differences in nutrient intake. APPLICATIONS/CONCLUSIONS: The CFC is a reliable and valid tool for measuring fat, saturated fat, and sodium intake in middle school students. Its brevity and ease of administration make the CFC a cost-effective way to measure middle school students' previous day's intake of selected nutrients in school surveys and intervention studies.     

THE VALUE OF UNENHANCED HELICAL COMPUTERIZED TOMOGRAPHY IN THE MANAGEMENT OF ACUTE FLANK PAIN

Purpose

We developed an algorithm using unenhanced computerized tomography (CT) for the management of acute flank pain and suspected ureteral obstruction.

Materials and Methods

During a 25-month interval 417 patients with acute flank pain underwent unenhanced helical CT. The final diagnosis was confirmed by additional imaging or clinical followup. For all patients who underwent additional imaging studies the official dictated radiology reports were used to determine whether the studies were recommended based on CT findings. Cases requiring intervention were evaluated to determine whether additional imaging was performed before the procedure. Medical records were reviewed and/or patients were interviewed to document the course of therapy and long-term outcome.

Results

Unenhanced helical CT diagnosed ureteral stone disease with 95% sensitivity, 98% specificity and 97% accuracy. Of the 38 patients requiring intervention, including nephrostomy catheters in 18, lithotripsy in 3 and ureteroscopic stone extraction in 7, additional imaging (excretory urography) was performed in only 1. Additional imaging studies generated by CT were done in 3 cases in which the dictated reports were indeterminate for ureteral stones, including negative excretory urography in 2 and retrograde urography in 1. In 1 patient in whom CT misdiagnosed a ureteral stone unnecessary retrograde urography revealed the calcification to be a gonadal vein phlebolith. Seven patients with false-negative examinations reported spontaneous stone passage with no complications.

Conclusions

Unenhanced helical CT accurately determines the presence or absence of ureterolithiasis in patients with acute flank pain. CT precisely identifies stone size and location. When ureterolithiasis is absent, other causes of acute flank pain can be identified. In most cases additional imaging is not required.