Parvovirus B19-associated hemophagocytic syndrome

Parvovirus B19 is a recently described pathogen, associated with an increasing spectrum of clinical manifestations. We present the first reported case, to our knowledge, of parvovirus B19-associated hemophagocytic syndrome, in which the diagnosis of parvovirus infection was documented by the presence of B19-specific IgM and IgG antibodies. Pancytopenia resolved immediately following splenectomy and the patient recovered completely.     

EVIDENCE FOR DIRECT INTERACTION OF KETAMINE WITH α- AND β2-ADRENOCEPTORS

1. Ketamine has a number of effects that suggest that it may interact with α- and β-adrenoceptors. To date, the experimental evidence for this has been indirect and has been based on physiological studies using competitive blocking agents. In the present study we sought to determine from receptor binding studies whether ketamine binds directly to α- and β-adrenoceptors. 2. Membrane preparations o. α₁- and β₂-adrenergic binding sites were obtained from urinary bladder and urethrae of sheep. These binding sites were characterized by saturation analyses using [³H]-prazosin for α₁-adrenoceptor binding sites and [¹²⁵I]-cyanopindolol (CYP) for the β₂-adrenoceptor binding sites. The receptors were further characterized by displacement studies using selective and non-selective antagonists. 3. Studies in which ketamine was used to displac. [³H]-prazosin revealed a K_d of 3.40±1.23× 10^?3 mol/L for ketamine binding to ai-adrenoceptors. Displacement studies of [¹²⁵I]-CYP by ketamine showed a K_d of 0.35±0.03× 10^?3 mol/L for ketamine binding to β₂-adrenoceptors. 4. We conclude that ketamine interacts directly with both ai- an. β₂-adrenoceptors and that such interactions probably explain the reported effects of this agent on the vasculature and the bronchial tree.     

Clonidine and lidamidine to inhibit watery diarrhea in a patient with lung cancer

A patient with watery diarrhea syndrome secondary to bronchogenic carcinoma responded to treatment with clonidine and lidamidine. Stool weight decreased to 43% and 53% of control on two separate trials of clonidine. Stool weight decreased to 35% of control during a trial of lidamidine. Both clonidine and lidamidine increased sodium and chloride absorption in vitro in human intestine. Clonidine, lidamidine, or drugs that are structurally similar may become therapeutic choices for secretory diarrhea.     

A laboratory animal model for malignant hyperpyrexia.

Strandard laboratory rabbits which are not genetically susceptible to malignant hyperpyrexia were anesthetized with either halothane or pentobarbital. Administration of caffeine in 125 mg increments produced a syndrome strongly resembling malignant hyperpyrexia in rabbits anesthetized with halothane. All these animals became rigid, hyperpyrexic, acidotic and hyperkalemic, whereas caffeine-treated, pentobarbital-anesthetized animals developed only mild acidosis. Pentobarbital alone and halothane alone caused no changes in measured variables. This model for malignant hyperpyrexia resembles the naturally occurring disease more closely than several preceding pharmacologic models.     

The advantages of delayed imaging and radiographic correlation in scintigraphic localization of gastrointestinal bleeding

Two cases in which gastrointestinal bleeding was localized by serial scintigraphic imaging with red blood cells labeled in vivo with 99mTc-PYP are reported. The importance of both early serial imaging and delayed imaging and of the correlation with other radiographic techniques is demonstrated. Reflux of blood from the sigmoid into the proximal colon was observed in both cases. In one case, contrast material injected into a resected specimen confirmed the scintigraphic localization of the site of bleeding.