Effect of meal on the physiological and physicochemical actions of potassium citrate

The effect of meals on the physiological and physicochemical actions of potassium citrate was examined in 8 patients with nephrolithiasis maintained on a constant metabolic dietary regimen. Potassium citrate (20 mEq. 3 times per day), whether given with food or on an empty stomach, significantly increased urinary pH, citrate and potassium, and decreased urinary calcium and ammonium. Moreover, potassium citrate decreased urinary saturation of calcium oxalate and uric acid, although it slightly increased that of brushite. However, there was no significant difference in these measures when the drug was given with meals from the time when it was given on an empty stomach. Thus, the effect of potassium citrate on urinary risk factors is unaffected by food.     

Tourette syndrome and neuropsychological performance

This study examined performance on a battery of neuropsychological tests in a sample of 28 patients with Tourette's syndrome (TS). Test scores were converted to age-corrected T-scores to control for the effect of age on test performance. The frequency of abnormal test performances was variable, but more frequent on motor and sensory tasks. Symptom severity as measured by the Tourette Syndrome Global Scale was inversely related to neuropsychological performance. In general, neuropsychological performance was mildly below average. The pattern of performance was similar to previous studies of TS patients.     

Dog bites in urban children

As a result of a perceived increase in pit bull injuries, all children who presented to The Children's Hospital of Philadelphia during 1989 for evaluation of dog bite injuries were prospectively studied. Epidemiologic information was collected from parents, either at the time of visit or by phone on the following day. A total of 168 children were enrolled; the mean age was 8 years. Males outnumbered females 1.5:1. Most (61%) injuries occurred in or around the home and involved dogs known to the patient (77%). Types of injuries included abrasions (33%), punctures (29%), and lacerations (38%). Thirteen bites had associated complications; nine developed infection. Twelve (7%) children required admission to the hospital. More than 12 different purebreeds or cross-breeds were identified as perpetrators, including German shepherds (n = 35), pit bulls (n = 33), rottweilers (n = 9), and Dobermans (n = 7). Most (54%) animals were contained (ie, leashed, fenced, in-house) at the time of injury. Fewer (46%) were provoked prior to biting. Significantly more pit bull injuries (94% vs 43%, P less than .001) were the consequence of unprovoked attacks and involved freely roaming animals (67% vs 41%, P less than .01). Children aged 5 or younger were more likely to provoke animals prior to injury than were older children (69% vs 36%, P less than .001). It is recommended that families with young children be the target of pet safety education and that measures be sought that would lead to early identification of a potentially dangerous dog and restrict ownership.     

Evidence for a decrease in sympathetic control of intestinal function in the aged rat.

The ability of carbachol and isoprenaline to contract and relax respectively the longitudinal layer of ileal smooth muscle has been compared in rats aged six and twenty-four months. The concentration response curve to carbachol did not vary with the age of the animal. In contrast, the ability of isoprenaline to relax longitudinal smooth muscle precontracted with carbachol was significantly (p less than 0.02) reduced in the twenty-four month age group. This reduced response was due to a decrease in the maximal relaxation induced by isoprenaline rather than by a shift to the right of its dose-response curve. These results are discussed in the context of previous histochemical and microscopical studies which have shown a marked reduction in the density of the sympathetic innervation of the rat small intestine in old age.     

Familial and sporadic hyperinsulinism: histopathologic findings and segregation analysis support a single autosomal recessive disorder

We evaluated the possible genetic contribution to hyperinsulinism in a series of patients seen during the past 15 years. Of 26 families, 5 (19%) had more than one child affected (multiplex family). There were no apparent differences between patients in the 5 multiplex and 21 simplex families, clinically, biochemically, or on histologic examination of the pancreatic specimens. The families studied had a total of 63 offspring; the 26 index patients had 37 siblings, 6 of whom were affected. After four patients with hyperinsulinism caused by adenoma were excluded from the study, segregation analysis was carried out to test the data for agreement with results expected if familial and isolated hyperinsulinism represented a single disease with recessive mode of inheritance and a segregation ratio of 0.25. Excellent agreement was found between the observed number of affected siblings (20) and the expected number (19.65), with a segregation ratio of 0.254. The results were consistent with the hypothesis that in most or all cases, hyperinsulinism is inherited as an autosomal recessive disease. There was no evidence of distinct familial and sporadic types.     

Role of substance P in several models of bladder inflammation

Substance P (SP) is a peptide found in the sensory nervous system which has multiple biologic effects including stimulation of muscle contraction, pain nociception, immune cell functions, plasma extravasation and a constellation of inflammatory effects. Here we investigate the role of SP in several animals models of bladder inflammation. Using the female Lewis rat, inflammation was induced using either xylene, lipopolysaccharide (LPS) or polyinosinic-polycytidylic acid (polyIC). Inflammation occurred rapidly (4 h) and was maintained in each model for at least 7 days. Each of these protocols decreased the bladder content of immunoreactive SP by approximately 50%, suggesting enhanced release. There was no change in the urinary frequency of these animals over 3 weeks, suggesting that urinary frequency changes are not mediated by acute inflammation. We also found that the SP receptor (NK₁) antagonist, (?)CP96345, was unable to block the inflammation produced by polyIC, suggesting that SP is not an obligatory mediator of immune cell stimulation in this model.     

Head injuries incurred by children and young adults during informal recreation.

To examine injuries related to playground equipment, children's vehicles, roller skates, and skateboards, 1991 data on emergency room patients younger than 25 years in the Consumer Product Safety Commission's 91 surveillance hospitals were used. Head injury was the primary diagnosis for an estimated 58,480 patients, exceeding the total number of head injuries to bicyclists younger than 25 years. The head injury rate decreased with age. The large number and high rate of head injuries in children involved in a variety of recreational activities suggests the value of multipurpose helmets.     

A comparison of acceleromyography and mechanomyography for determination of the dose–response curve of rocuronium in children

In order to compare an acceleromyograph (TOF-Guard^TM) with a mechanomyograph (Grass FT03), the dose–response relationship of rocuronium was simultaneously determined in both arms of 15 children aged 3–11 years during anaesthesia with thiopentone, alfentanil and nitrous oxide. Three subgroups of five children received rocuronium 120, 180 or 240 μg.kg⁻¹ randomly. The effective doses to produce 50% and 95% depression of the first twitch of the train-of-four determined by acceleromyography were 206 and 337 μg.kg⁻¹, respectively, while these values determined by mechanomyography were 151 and 331 μg.kg⁻¹, respectively. The dose–response curve obtained by acceleromyography was steeper and shifted to the right compared with that obtained by mechanomyography (p < 0.0001). The difference between the effective dose producing 50% twitch depression determined by the two devices was highly significant (p < 0.0001). In 13 out of 15 children, the acceleromyograph control train-of-four ratio was significantly greater than unity. Although there was a good correlation ( r  = 0.85) between simultaneous pairs of measurements of neuromuscular block, the acceleromyograph exhibited a bias of −25% relative to the mechanomyograph with wide limits of agreement (−62 to +12%). We conclude that acceleromyographic and mechanomyographic measurements should not be used interchangeably when determining the potency of muscle relaxants.     

Posterior beam-stop method for scatter fraction measurement in digital radiography.

The authors presented a new posterior beam-stop (PBS) technique for measuring the ratio of scattered to total-detected photon flux (scatter fraction) in a radiographic examination while preserving the diagnostic quality of the image. The scatter measurement was made using a standard imaging geometry with both beam stops and an additional x-ray detector placed behind the standard imaging detector. This PBS geometry differs from the standard beam-stop (SBS) technique for scatter measurement. With SBS, a beam-stop shadow appears on the image. To evaluate the PBS technique, scatter fraction measurements were performed on an anatomic phantom using both the PBS and SBS techniques. When compared with the standard technique, PBS provided accurate estimation of scatter fractions. Since the measurement can be performed without degrading a standard clinical radiographic examination, the PBS technique allows simultaneous acquisition of scatter measurements from human patients in combination with a standard radiographic examination.