Juvenile-onset acid maltase deficiency with unusual familial features

From early childhood, two brothers had mild gait difficulties due to acid maltase deficiency (AMD). Biochemical studies of family members were consistent with autosomal recessive inheritance, but the asymptomatic mother had AM activity in the homozygote range, and her parents had decreased AM activity. The asymptomatic mother may be homozygous for the adult-onset variant of AMD. Alternatively, either the mother or the children may be genetic compounds of the childhood and adult forms of AMD.     

Imipenem therapy of experimental Staphylococcus epidermidis endocarditis.

Imipenem was evaluated for its activity against Staphylococcus epidermidis in vitro and in a rabbit model of endocarditis. The MBC for imipenem of 55 methicillin-resistant S. epidermidis isolates from patients with prosthetic valve endocarditis increased by eightfold or greater with increasing inoculum size; there was no inoculum-associated increase in the imipenem MBC for 20 methicillin-susceptible S. epidermidis isolates. Endocarditis was produced in rabbits with either a methicillin-susceptible or a methicillin-resistant S. epidermidis isolate to investigate the correlation in vivo of the in vitro inoculum effect for imipenem. Six days of imipenem treatment eradicated methicillin-susceptible S. epidermidis from vegetations of infected rabbits significantly better than no therapy but was less effective against methicillin-resistant S. epidermidis in this regard. Among methicillin-resistant S. epidermidis-infected rabbits, 6 days of imipenem therapy (i) was not significantly better than that of the control and was significantly worse than that of vancomycin in eradicating bacteria from infected vegetations and (ii) increased the frequency of imipenem-resistant subpopulations in infected vegetations. Resistant subpopulations were not seen in vegetations from untreated or imipenem-treated, methicillin-susceptible S. epidermidis-infected rabbits. Imipenem may not be effective therapy for serious human methicillin-resistant S. epidermidis infections.     

Similarity assessment and attribute scaling of sucrose and aspartame in grape drink

The present study investigated the perception of sweetness of aspartame in comparison to various concentrations of sucrose. Twenty-seven subjects were randomly assigned to taste a chilled or room temperature Kool-Aid beverage sweetened with either aspartame or five different concentrations of sucrose. Subjects assessed the perceived similarity in sweetness of an aspartame-aspartame pair and five different aspartame-sucrose pairings and rated each beverage on five bipolar adjectives. Analysis of the similarity ratings revealed that subjects did not perceive the pairs of beverages to differ in perceived sweetness. Analysis of the adjective ratings revealed that aspartame and the lower sucrose concentrations were perceived as being less sweet and more sour than the higher sucrose concentrations.     

Affinity labeling of mu opioid receptors by sulfhydryl alkylating derivatives of morphine and morphinone.

After reduction of a disulfide bond at or near the mu opioid binding site in rat brain membranes, incubating membranes with 14 beta-bromoacetamido derivatives of either morphine, dihydromorphine, morphinone, or dihydromorphinone resulted in the irreversible inhibition of mu opioid binding to rat brain membranes. Without the addition of the disulfide bond-reducing reagent dithiothreitol, these affinity ligands bound reversibly to opioid binding sites. Binding to either delta or kappa opioid binding sites was not altered by alkylation of the membranes with the affinity ligands. The percentage of irreversible inhibition of mu opioid binding was dependent on the time and temperature of the incubation of membranes with the affinity ligands and on the concentrations of dithiothreitol and the affinity ligands. Incubating membranes with morphine afforded almost complete protection from alkylation of the mu opioid binding site. Naloxone and the l-isomer levorphanol also protected the site from alkylation, whereas the d-isomer dextrorphan and the kappa-selective opioid U50,488H did not protect the site. The mu-selective peptide [D-Ala2, (Me)Phe4,Gly(ol)5]enkephalin was the peptide that afforded the greatest protection. These studies have shown that, after the reduction of a disulfide bond at or near the mu opioid binding site, this sulfhydryl group can be specifically alkylated, resulting in the affinity labeling of the mu opioid binding site.     

Lack of effects of prenatal exposure to lidocaine on development of behavior in rats

The objective of this investigation was to study the effects of lidocaine upon postnatal development of the rat. Lidocaine, 6 mg/kg (21 mumol/kg), was given to a group of 12 rats. Injections were administered intramuscularly, bilaterally in the masseter muscles, once a day on days 10 and 11 of pregnancy. Twelve control rats were given physiologic saline. Clinical signs, mortality, body weight, and food consumption were recorded during pregnancy and lactation. The duration of gestation was also recorded. The development of the offspring was monitored by tests of spontaneous activity, nociception, learning ability, and physical development. No clinical signs of adverse reactions were seen in any of the groups. In the majority of the learning ability tests, the control and lidocaine-treated groups showed similar results. However, in the schedule of differential reinforcement of low rates of responding (DRL 20), the lidocaine-exposed males received more reinforcements than the controls and made fewer responses. In the tests of nociception, a significant difference between sexes was recorded, in that the females were more sensitive than the males in the shock-titration test. Physical development, as monitored by swimming ability and spontaneous activity, showed no inter-group difference. The present results indicate that prenatal exposure to lidocaine fails to result in postnatal impairment of the development of behavioral performance of a wide range of tasks.     

Status of an unpaired thiol group on the HLA-B27 epitope.

In a previous study we demonstrated that mitogen-stimulated CD8+ CD4-T cells from normal donors produce a suppressive lymphokine (PASL) of IgE-dependent platelet cytotoxicity. Here we demonstrate the production, after antigenic-stimulation, of this suppressive factor during ongoing infections by Schistosoma mansoni in man and in the rat. The T lymphocyte subpopulation producing this factor was also identified as expressing the marker of the suppressive subset. Because of the absence of species restriction, the relevance in vivo of PASL was determined in the rat model. In these conditions we observed a complete abolition of the protection normally conferred against a challenge infection by the passive transfer of platelets from immune to normal rats after treatment of transferred platelets with T lymphocyte supernatants.     

A physiological approach to surgery for acute rupture of the papillary muscle

There is controversy regarding the optimal management of patients in whom acute papillary muscle rupture develops. This study evaluates the effect of division of the anterolateral papillary muscle on left ventricular (LV) function and compares two methods of treatment--mitral valve replacement (MVR) and mitral valve repair. Thirteen pigs were placed on cardiopulmonary bypass, and interventions were performed in an isolated beating heart preparation. LV function was assessed with a compliant intraventricular balloon at baseline, after division of the anterolateral papillary muscle (Divided), after repair of the divided papillary muscle (Repair), and finally after MVR. Division of the anterolateral papillary muscle caused a significant deterioration in LV function. Function was maintained at this level after mitral valve repair but deteriorated with MVR. Developed pressure measured at baseline was 179 +/- 13 mm Hg; Divided, 148 +/- 11 mm Hg (p less than 0.05 versus baseline); Repair, 149 +/- 15 mm Hg; and MVR, 95 +/- 8 mm Hg (p less than 0.05 versus Divided) at a balloon volume of 20 ml. These results suggest that LV function is impaired by papillary muscle rupture. Repair of the ruptured papillary muscle is associated with better LV function than is MVR.     

N-methylcarbamate derivatives of ellipticine and olivacine with cytotoxic activity against four human lung cancer cell lines.

A series of analogues of the antitumor alkaloids ellipticine and olivacine were tested for cytotoxicity against four human lung cancer cell lines: H69, N417, H460, and H358. Adriamycin (doxorubicin), ellipticine, olivacine, and celiptinium were used as standards. Adriamycin was cytotoxic at 2 microM and celiptinium was inactive at the highest concentrations tested (IC50 > 48 microM). N-methylcarbamates of 9-methoxy-6H-pyrido[4,3-b]carbazole 1-,5-, and 11-methanols gave IC50 values ranging from 0.02 to 0.11 microM against N417, H460, and H358 and were only slightly less effective against H69.