Benzamide action at α2-adrenoceptors modifies catecholamine-induced contraction and relaxation of circular smooth muscle from guinea-pig stomach

Summary Dopamine was shown to act on the circular smooth muscle of the stomach body to cause contraction at a yohimbine-sensitive site (₂) and a relaxation at a prazosin-sensitive site (₁). Metoclopramide and tiapride failed to modify either response, failed to antagonise a relaxation to phenylephrine at 1(₁ sites in the same tissue, and failed to modify the contractions caused by dopamine and phenylephrine at an ₂-adrenoceptor site in the pyloric sphincter. However, (+)- and (–)-sultopride and (+)-sulpiride antagonised the dopamine-induced contractions of the stomach body indicating an ₂-antagonist action. An ability to attenuate the relaxation of this tissue may reflect a displacement of the contraction curve to the right rather than an ₂-antagonist action since the response to phenylephrine was not antagonised either in this tissue or in the pyloric sphincter. Within the central nervous system the (–)-enantiomers of sultopride and sulpiride have a highly selective dopamine receptor blocking action. This cotrasts with the present findings in the stomach musculature of a non-stereospecific antagonism at ₂-type adrenoceptors.     

Urinary low-molecular-weight protein excretion in pediatric idiopathic nephrotic syndrome

Background

Minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) are the most common causes of idiopathic nephrotic syndrome (INS). We have evaluated the reliability of urinary neutrophil-gelatinase-associated lipocalin (uNGAL), urinary alpha1-microglobulin (uα1M) and urinary N-acetyl-beta-D-glucosaminidase (uβNAG) as markers for differentiating MCD from FSGS. We have also evaluated whether these proteins are associated to INS relapses or to glomerular filtration rate (GFR).

Methods

The patient cohort comprised 35 children with MCD and nine with FSGS; 19 healthy age-matched children were included in the study as controls. Of the 35 patients, 28 were in remission (21 MCD, 7 FSGS) and 16 were in relapse (14 MCD, 2 FSGS). The prognostic accuracies of these proteins were assessed by receiver operating characteristic (ROC) curve analyses.

Results

The level of uNGAL, indexed or not to urinary creatinine (uCreat), was significantly different between children with INS and healthy children (p?=?0.02), between healthy children and those with FSGS (p?=?0.007) and between children with MCD and those with FSGS (p?=?0.01). It was not significantly correlated to proteinuria or GFR levels. The ROC curve analysis showed that a cut-off value of 17 ng/mg for the uNGAL/uCreat ratio could be used to distinguish MCD from FSGS with a sensitivity of 0.77 and specificity of 0.78. uβNAG was not significantly different in patients with MCD and those with FSGS (p?=?0.86). Only uα1M, indexed or not to uCreat, was significantly (p?<?0.001) higher for patients in relapse compared to those in remission.

Conclusions

Our results indicate that in our patient cohort uNGAL was a reliable biomarker for differentiating MCD from FSGS independently of proteinuria or GFR levels.     

Shunt nephritis

Six children with shunt nephritis are reported of whom two did not show complete recovery of renal function. Follow up and outcome in relation to the delay in diagnosis and renal biopsy appearances are discussed.     

A painful limp

We describe a healthy 18-month-old child who developed a painful limp, without a history of trauma or fever. The initial laboratory investigations showed normal results but the radiological findings were suggestive of scurvy. Diagnosis was confirmed by blood tests and by a rapid recovery following replacement therapy.     

Feeding problems with the first feed in neonates with meconium-stained amniotic fluid

OBJECTIVE:

To compare the incidence of feeding problems at the first feed between neonates born with meconium-stained amniotic fluid (MSAF) and those born without MSAF.

DESIGN:

A prospective observational study conducted over a one-year period.

SETTING:

A level 2 neonatal unit.

POPULATION STUDIED:

A total of 2828 neonates were studied, including 275 neonates with MSAF. All neonates were born after more than 34 weeks of gestation, and had no birth asphyxia, hemodynamic, respiratory distress or major congenital anomalies. The neonates were offered a feed within 1 h of birth, and the incidence of early feeding problems (ie, retching, vomiting, slow feeding or poor suck) was studied.

RESULTS:

Feeding problems at the first feed developed in 55 infants (13 of 275 with MSAF and 42 of 2533 without MSAF). Feeding problems were more common in infants with MSAF (P=0.001, relative risk=2.8, 95% CI 1.45 to 5.63), regardless of the type of MSAF (thin or thick). Although fetal distress was more frequent in the MSAF group, there were no differences in the 1 and 5 min Apgar scores whether meconium was present. Maternal sedation was not found to be a contributing factor. The mechanical and chemical actions of meconium inside the stomach requires further study.

CONCLUSION:

Feeding problems at the first feed are 2.8 times more frequent in neonates born with MSAF, regardless of the consistency of the amniotic fluid. Mothers of such infants need to be informed and supported during feeding to minimize discouragement. The demands on the nursing staff must be anticipated accordingly.