Localisation of a mutation producing autosomal dominant polycystic kidney disease without renal failure.

A four generation Finnish family was identified with atypical features of adult polycystic kidney disease. All members of the extended pedigree were asymptomatic and none had developed renal failure. Previous studies have shown close linkage between the adult polycystic kidney disease locus and the alpha chain of human haemoglobin on chromosome 16, but these studies were carried out on families manifesting 'typical' clinical features of the disease. In order to determine whether the atypical clinical features observed in this Finnish family were produced by a mutation at the same or a second locus, linkage studies were carried out using a highly polymorphic DNA marker from the alpha globin cluster. Here we show that the mutation producing the disease in this Finnish family is also closely linked to alpha globin.     

Trans-suppression of defense DEFB1 gene in intestinal epithelial cells following Cryptosporidium parvum infection is associated with host delivery of parasite Cdg7_FLc_1000 RNA

Parasitology Research - To counteract host immunity, Cryptosporidium parvum has evolved multiple strategies to suppress host antimicrobial defense. One such strategy is to reduce the production of...     

Stimulation of C fibers by ammonia vapor triggers mucociliary defense reflex

The neuropeptide substance P (SP) released from airway sensory C fibers accelerates mucociliary activity, and C fibers in the airways are stimulated by various irritants including ammonia (NH3) vapor. The short-term effects of NH3 vapor on mucociliary function in the in the maxillary sinus of rabbits anesthetized with urethane were investigated by a photoelectric technique. Challenges with 1.5 ml NH3 increased mucociliary activity dose-dependently, the maximal response being 26.6 +/- 1.6%. The increase appeared within 1.3 +/- 0.3 s after exposure. Atropine and hexamethonium decreased the effect of NH3, indicating that part of the response was mediated by cholinergic effector neurons, but a noncholinergic effect clearly remained. Pretreatment with large doses of capsaicin (13 mg i.a.) abolished the response, whereas the SP antagonist (D-Pro2, D-Trp7,9) SP inhibited the noncholinergic response. Challenges with NH3 vapor also decreased the respiratory rate. An identical response was noticed during injections with the C fiber stimulant capsaicin. Together these results indicate that NH3 vapor triggers a mucociliary protective reflex in the airways, involving capsaicin-sensitive C fibers. The recorded increase of mucociliary activity is probably due to the combined effect on the mucociliary system of both SP and acetylcholine released from the afferent and efferent part of the reflex arc, respectively.     

Mucociliary activity and the diving reflex

It has previously been shown that mucociliary activity in the rabbit maxillary sinus is immediately increased after short-term exposure to such airway irritants as cigarette smoke and ammonia vapor. This increase is mediated through the stimulation of capsaicin-sensitive nerve endings. Besides producing the mucociliary effect, these irritants inhibit breathing, a response characteristic of the diving reflex in mammals. Whether an increase in mucociliary activity is part of the diving reflex was investigated by injecting 0.5 mL water into the nasopharynges of anesthetized rabbits. Mucociliary and respiratory responses were compared with the effects of mechanical stimulation (ie, rotating an intranasal catheter until sneezing occurred). Water challenge produced an increase in mucociliary activity of 21.6% +/- 2.4%, a response that began approximately 10 seconds after injection. Mucociliary acceleration was completely blocked by atropine, indicating a cholinergic mechanism, but was unaffected by pretreatment with capsaicin. The respiration rate was inhibited by about 45% after challenge with water. Pretreatment with atropine and capsaicin had no effect on this reduced respiratory rate. Mechanical stimulation of the nasal mucosa accelerated mucociliary activity. This response appeared approximately 4 seconds after stimulation was begun, and occurred simultaneously with the onset of sneezing. The peak increase was 22.0% +/- 2.1%. Sneezing was followed by an increase in the respiration rate of about 40%. Pretreatment with atropine or capsaicin had no effect on respiratory responses, but did inhibit mucociliary acceleration, suggesting that the response is mediated through cholinergic effector neurons after activation of capsaicin-sensitive nerve endings.(ABSTRACT TRUNCATED AT 250 WORDS)     

Part C Early Intervention Enrollment in Low Birth Weight Infants At-Risk for Developmental Delays

Objectives To investigate enrollment patterns in Part C Early Intervention (EI) for low birth weight (LBW) infants (≤2500 g). A secondary aim is to characterize LBW infants that are not enrolled in EI, but would qualify by meeting criteria for a condition associated with a “high-probability” for developmental delays (i.e., Intraventricular Hemorrhage grade III or higher, Apgar score of ≤5 at 5 min, and/or birth weight of ≤1200 g). Methods Data were gathered from 165 LBW infants participating in a high-risk infant follow-up program. Developmental assessment was completed. Basic demographic information and data regarding enrollment in EI were collected via parent questionnaire. Medical variables were extracted from each infant’s electronic medical record. Results 71.5 % of LBW infants were not enrolled in EI. Factors influencing probability of EI enrollment included birth weight, gestational age, developmental test scores, and insurance status. Of the 107 infants living in Oregon who were not enrolled in EI, 42.1 % would qualify for services due to an early medical condition identified in Oregon as a condition associated with a “high-probability” for developmental delays. Conclusions Less than one third of LBW infants were enrolled in EI by their first visit to a high-risk infant follow-up program. Those infants demonstrating developmental delays and public insurance were more likely to be enrolled. The majority of infants who have readily identifiable medical risk factors that qualify them for EI were not enrolled. This study was limited by the constraints implicated by using a clinical sample.     

Factors influencing 133-xenon washout in a nose-sinus model.

The 133-xenon washout technique is a non-invasive method for the evaluation of ventilation of the paranasal sinuses. The half-time of 133-xenon washout (T(1/2)) is considered to reflect sinus ostial function and sinus ventilation. However, it is not known how morphological and physiological factors affect the washout from the paranasal sinuses. The aim of the present study was to evaluate how sinus volume, ostial diameter and nasal ventilation influence 133-xenon washout in a nose-sinus model. This is important for the interpretation of measurements of 133-xenon washout from paranasal sinuses in healthy subjects and in subjects with sinus disease. The 133-xenon washout was measured with a scintillation camera. The statistical analysis of the results showed that the logarithm (to the base 10) of the half-time of 133-xenon washout is linearly related to the ostial diameter, the sinus volume and the nasal ventilation in the model. In a multiple linear regression model, the most important factor contributing to 133-xenon washout was found to be the ostial diameter, which explained 76% of the variation in log T(1/2). In the same statistical model the sinus volume explained 7.5% and the ventilation 5.3% of the variation in log T(1/2). Calculations of the functional ostial diameter in healthy subjects were made, based on the results of the model study. The mean functional ostial diameter was found to be 3.5 mm (range 0.5-7.5 mm). The results obtained with the present model experiments may be of importance for the correct interpretation of the results of measurements of 133-xenon washout in healthy subjects and patients.     

The role of neurokinin A and calcitonin gene-related peptide in the mucociliary defence of the rabbit maxillary sinus

Substance P (SP) released from sensory C-fibres in the airways increases the mucociliary (m.c.) activity in the rabbit maxillary sinus. The purpose of the present study was to investigate the m.c. effects of two other neuropeptides, coexisting with SP in sensory neurones, neurokinin A (NKA) and calcitonin gene-related peptide (CGRP). NKA increased the m.c. activity dose-dependently (dose range 0.1-5.0 micrograms/kg) the maximum increase being 33.6 +/- 6.0%. The effect was inhibited by pretreatment with the tachykinin antagonist (D-Pro2, D-Trp7,9)SP, but not with atropine or hexamethonium. Thus NKA released from sensory C-fibres may contribute to the non-cholinergic increase of m.c. activity observed after C-fibre stimulation. In contrast CGRP did not influence the m.c. activity. Neither did it influence the responses to NKA or SP. It is concluded that CGRP is unlikely to be involved in the control of m.c. function.     

Experiences of Kidney Transplant Recipients as Patient Navigators

Background and objective

The use of trained kidney transplant recipients as patient navigators resulted in increased completion of the steps in the transplant process by dialysis patients. We sought to understand the experiences of these patient navigators.