The role of chewing lice (Phthiraptera: Philopteridae) as intermediate hosts in the transmission of Hymenolepis microps (Cestoda: Cyclophyllidea) from the willow ptarmigan Lagopus lagopus (Aves: Tetraonidae).

The cestode Hymenolepis microps is an intestinal parasite of tetraonid birds, including the willow ptarmigan (Lagopus lagopus). This parasite is able to maintain a high prevalence and intensity throughout the year, even in a subarctic environment in bird populations with relatively low host densities, indicating effective transmission routes. Willow ptarmigan consume mainly vegetal material and active consumption of invertebrates is confined to the first two or three weeks of life. Ptarmigan are infected by different species of ectoparasites, of which two species of feather lice, Lagopoecus affinis and Goniodes lagopi, are the most abundant. In this study, we explored the hypothesis that feather lice may be suitable intermediate hosts for H. microps. We applied histological techniques and light microscopy to investigate lice for the presence of larval cestode stages (cysticercoids). We found 12 cysticercoid-like structures inside chewing lice collected on L. lagopus hosts harbouring H. microps. In addition, a polymerase chain reaction (PCR) screening of Ischnocera lice DNA, targeting the 18S rRNA gene of the cestode, showed positive results for two different short fragments of the 18S rRNA gene of H. microps which were sequenced from lice collected on birds. Both independent lines of evidence support the hypothesis that Ischnocera lice might be suitable intermediate hosts in the life cycle of H. microps in L. lagopus.

Different neurologic outcomes in two patients with neonatal hyperinsulinemic hypoglycemia.

The authors report the cases of two patients with neonatal onset of hypoketotic hypoglycemia with hyperinsulinism and a poor response to diazoxide. Pancreatic venous sampling showed a diffuse pancreatic hyperplasia in one patient and a focal lesion in the other. The second patient, diagnosed after a significant delay, suffered severe long-term neurological sequelae, despite having more limited hyperplasia; the brain MRI also showed severe pathological changes in cortex and white matter, predominantly in the parieto-occipital region. Early and accurate diagnosis is critical in these patients in whom hypoglycemia is compounded by a lack of the ketone bodies which represent a vital alternative source of energy for the central nervous system.

A problem associated with the use of a calomel reference electrode in an ISE analytical system.

It was discovered during the testing of a new diluted ISE analytical system that a dark deposit formed in the vicinity of the reference electrode junction and on the junction membrane over a 1-3 month period of use. The effect of the black deposit was to shorten the life of the restricted flow reference membrane and increase the time required to maintain the system in its optimum state. Elemental analysis of the deposit revealed the presence of both mercury and sulfur. The rate of deposit build-up was found to depend on the concentrations of both the buffer and the microbicide in the system's reagents. The cause was traced in part to the generation of sulfide ions as a breakdown product of the microbicide. The disproportionation of calomel, Hg2Cl2, in saturated KCl to give Hg2+chloro-complexes and their reaction with sulfide ions at the reference junction resulted in HgS being deposited. Design changes over previous systems contributed to the effect by increasing residence time of calibrant solution at the reference junction and decreasing the frequency of reference electrolyte and membrane changes. Adding complexing agents to the reference fill solution lessened but did not eliminate the problem. The problem was solved without reformulating the reagents by using a reducing agent proximate to the calomel mercury amalgam to reduce mercuric ions to metallic mercury. This also prevents discharge of environmentally undesirable mercuric ions into the waste solution.

DHPR activity decrease in dried blood spots stored at 4 degrees C.

Dihydropteridine reductase (DHPR) activity has been measured in dried blood spots by the Arai method in 286 subjects divided into 4 groups: 45 newborns aged between 4 and 7 days; 40 subjects with hyperphenylalainaemia; 199 apparently normal subjects, and 2 patients with DHPR deficiency. Furthermore, a study of the persistence of enzymatic activity on the spots stored at 4 degrees C revealed that after 1 year it decreased to one third of the original value, corresponding to the mean value of controls minus 2 SD.