The additive nature of the human multisensory evoked pupil response

Pupillometry has received increased interest for its usefulness in measuring various sensory processes as an alternative to behavioural assessments. This is also apparent for multisensory investigations. Studies of the multisensory pupil response, however, have produced conflicting results. Some studies observed super-additive multisensory pupil responses, indicative of multisensory integration (MSI). Others observed additive multisensory pupil responses even though reaction time (RT) measures were indicative of MSI. Therefore, in the present study, we investigated the nature of the multisensory pupil response by combining methodological approaches of previous studies while using supra-threshold stimuli only. In two experiments we presented auditory and visual stimuli to observers that evoked a(n) (onset) response (be it constriction or dilation) in a simple detection task and a change detection task. In both experiments, the RT data indicated MSI as shown by race model inequality violation. Still, the multisensory pupil response in both experiments could best be explained by linear summation of the unisensory pupil responses. We conclude that the multisensory pupil response for supra-threshold stimuli is additive in nature and cannot be used as a measure of MSI, as only a departure from additivity can unequivocally demonstrate an interaction between the senses.

No Acute Effects of Choline Bitartrate Food Supplements on Memory in Healthy, Young, Human Adults

Choline is a dietary component and precursor of acetylcholine, a crucial neurotransmitter for memory-related brain functions. In two double-blind, placebo-controlled cross-over experiments, we investigated whether the food supplement choline bitartrate improved declarative memory and working memory in healthy, young students one to two hours after supplementation. In experiment 1, 28 participants performed a visuospatial working memory task. In experiment 2, 26 participants performed a declarative picture memorization task. In experiment 3, 40 participants performed a verbal working memory task in addition to the visuospatial working memory and declarative picture task. All tasks were conducted approximately 60 minutes after the ingestion of 2.0–2.5g of either choline bitartrate or placebo. We found that choline did not significantly enhance memory performance during any of the tasks. The null hypothesis that choline does not improve memory performance as compared to placebo was strongly supported by Bayesian statistics. These results are in contrast with animal studies suggesting that choline supplementation boosts memory performance and learning. We conclude that choline likely has no acute effects on cholinergic memory functions in healthy human participants.

Epoetin in the 'untransfusable' anaemic patient: a retrospective case series and systematic analysis of literature case reports

BACKGROUND

Erythropoiesis stimulating agents [erythropoietin (EPO)] have been recommended to treat anaemic patients who cannot receive or refuse blood tranfusion ('untransfusable' patients).

OBJECTIVE

The objective of the study was to quantify the association of EPO use with haemoglobin (Hgb) recovery in anaemic untransfusable hospitalised patients.

METHODS/MATERIALS

EPO treated anaemic untransfusable patients were identified through the combination of a retrospective case review and a systematic review of the medical literature. Literature reports of untransfusable patients not treated with any EPO were used as a comparator group. Hgb concentrations before and following EPO use were abstracted and used to determine the rate of Hgb recovery for each case. Multilevel mixed effects modelling was used to determine the association of Hgb recovery with EPO use.

RESULTS

A total of 76 EPO treated cases (19 cases from the retrospective hospital case review and 57 from the literature), and 33 non-EPO treated comparator patients from the literature were included in the study. Hgb increased similarly over time in all groups at an overall mean standard error (SE) rate of 0·13 (0·01) g dL(-1)  day(-1) . The Hgb recovery rate was higher in patients with lower baseline Hgb, regardless of EPO use. No association was found between the rate of Hgb recovery and EPO use, dose or therapy duration.

CONCLUSIONS

In anaemic, 'untransfusable' hospitalised patients, EPO use was not associated with increased Hgb recovery at anytime within 28 days.

Association of the dopamine transporter (SLC6A3/DAT1) gene 9-6 haplotype with adult ADHD

ADHD is a neuropsychiatric disorder characterized by chronic hyperactivity, inattention and impulsivity, which affects about 5% of school-age children. ADHD persists into adulthood in at least 15% of cases. It is highly heritable and familial influences seem strongest for ADHD persisting into adulthood. However, most of the genetic research in ADHD has been carried out in children with the disorder. The gene that has received most attention in ADHD genetics is SLC6A3/DAT1 encoding the dopamine transporter. In the current study we attempted to replicate in adults with ADHD the reported association of a 10-6 SLC6A3-haplotype, formed by the 10-repeat allele of the variable number of tandem repeat (VNTR) polymorphism in the 3' untranslated region of the gene and the 6-repeat allele of the VNTR in intron 8 of the gene, with childhood ADHD. In addition, we wished to explore the role of a recently described VNTR in intron 3 of the gene. Two hundred sixteen patients and 528 controls were included in the study. We found a 9-6 SLC6A3-haplotype, rather than the 10-6 haplotype, to be associated with ADHD in adults. The intron 3 VNTR showed no association with adult ADHD. Our findings converge with earlier reports and suggest that age is an important factor to be taken into account when assessing the association of SLC6A3 with ADHD. If confirmed in other studies, the differential association of the gene with ADHD in children and in adults might imply that SLC6A3 plays a role in modulating the ADHD phenotype, rather than causing it.

A common source outbreak of gastroenteritis in a teaching hospital

An outbreak of gastroenteritis at a large teaching hospital affected at least 52 workers. Investigation implicated a tuna salad, and the circumstances suggested Clostridium perfringens as the etiologic agent. The risk of such outbreaks may be reduced by cooling of ingredients prior to mixing and refrigeration in small steel containers.

[Characteristics of alcohol withdrawal delirium in surgical patients and recommendations for treatment]

An alcohol withdrawal syndrome affects the patient in a 'vulnerable phase' either after an operation or posttraumatically. It can be shown pathophysiologically, that the symptoms are caused by a hyperactivity of the central sympathetic nervous system and a disbalance of the neurotransmitters. As for these complex symptoms, a multi-layered treatment is required. We report on our experiences with 23 patients who were treated in our intensive care unit. The treatment included a benzo-diazepine and a drug effecting central alpha 2-receptors. Only three of these patients had to be intubated or ventilated. Because of the induced bradycardia monitor observation was required in all cases. The patients could be wakened up at any time and thus were co-operative for basic care. One patient died of pulmonary embolism, a second patient died of cardiovascular failure as a consequence of cardiac insufficiency.

Successful treatment of tumor embolism of a hypernephroma with complete occlusion of the left pulmonary artery

A tumor embolism with occlusion of the left pulmonary artery was the first manifestation of a hypernephroma. After angiographic diagnosis, embolectomy was performed successfully using the heart-lung-machine. Four days later, nephrectomy followed. In the meantime, the patient has experienced a period of 3 years free of symptoms and metastases.

Experimental and clinical experience with the different possibilities of preserving splenic tissue after rupture of the spleen

From clinical observation in adults, it is obvious that the preservation of the ruptured spleen is only possible in about 80% of all cases. Current evidence indicates that only the completely or partially intact spleen protects against pneumococcal sepsis. The best method of reimplantation has not yet been found.

[Immunoglobulin in the blood and peritoneal secretions during the early postoperative phase]

After abdominal surgery the immunoglobulins in the peritoneal fluid and in the serum were measured in the early postoperative period in 34 patients with benign and malignant lesions. In comparison with the preoperative value there was postoperatively a serum decrease of 30% of the immunoglobulins. In the serum there was no difference in the cancer and no cancer group. An important difference was noted in the concentration of the peritoneal cavity fluid values. After operation in the biliary tract the peritoneal immunoglobulins fell to 50% of the serum level but improved rapidly after the patient recovered. After cancer surgery on the colon, the IG level fell without any later improvement. Purulent abdominal infections led to levels of the IG in the peritoneal fluid that were almost impossible to measure.

[The effect of immunoglobulins in experimental peritonitis (author's transl)]

We measured the influence of different drugs on mortality and lung weights in a well known and standardized peritonitis model in rats. The results are: 1. Intraperitoneal injection of immune globulin in high dosage had little effect on our parameters. High mortality and interstitial pulmonary edema were observed. 2. The same results followed injection of 20% human albumin. 3. All animals injected intraperitoneally with a modern antibiotic (Securopen) survived. Interstitial pulmonary edema was observed. 4. The combined injection of an antibiotic and immune globulin (Gamma-Venin) had the best results. None of the rats came down with a lung injection or died.

Fever in the first six months of life: risks of underlying serious infection

The age-specific rate of elevated temperature over 37.8 C was evaluated in all infants less than 6 months of age (n = 1341) seen from July 1, 1974 to June 30, 1978 in a family practice clinic. Mild elevations (37.8 C-38.3 C) were common even in the first few months of life, and accounted for 20.7 per cent of infant visits. Temperatures greater than 38.3 C are uncommon in the first months of life but are seen more frequently with each succeeding month. Temperature elevation over 38.3 C was associated with a significantly higher rate of meningitis (p less than .01), otitis media (p less than .001) and lower respiratory infection (p less than .05). Significantly higher laboratory usage was documented in infants less than 3 months and for infants with temperature more than 38.3 C. The high rate of mild temperature elevations in young infants suggests that a selective diagnostic strategy directed at high-risk infants is important. Infants less than three months of age with a fever exceeding 38.3 C are calculated to have 21.5 times the risk of a serious underlying infection as infants older than three months with a similar temperature elevation. Clinical evaluation must remain an important tool in determining which febrile infants should be evaluated by further laboratory and diagnostic tests.