Some properties of dendritic macrophages from peripheral lymph

Peripheral lymph was collected from the skin and liver of sheep, and from the intestine of rats. The dendritic macrophages contained in it were isolated by centrifuging the lymph over a layer of 'Nycodenz'. Similar cells were produced by culturing mononuclear cells from venous blood, but the yields were very small. The numbers of dendritic cells in the lymph from the legs of sheep increased five-fold after xylene had been applied to the skin. Dendritic macrophages displayed abundant class II histocompatibility antigens on their surfaces, as well as immunoglobulins. Although the latter were probably acquired passively, they remained present for several days on cells cultured in vitro. When in vitro, dendritic cells could be shown to phagocytose marker particles, such as latex beads, but their performance was unimpressive compared to macrophages from the peritoneal cavities of rats. In contrast, their ability to phagocytose rapidly T4 phage or influenza viruses unequivocal and striking.     

Renal findings on radiological followup of patients with Beckwith-Wiedemann syndrome

PURPOSE: The Beckwith-Wiedemann syndrome is most commonly characterized by macroglossia and abdominal wall defect(s), and it carries a predisposition to embryonal tumors, including Wilms tumor. We report our experience with the character and incidence of renal disease in patients with the Beckwith-Wiedemann syndrome, and discuss the role of radiological followup. MATERIALS AND METHODS: We reviewed the medical records of all patients diagnosed with the Beckwith-Wiedemann syndrome who were treated at our institution between March 1979 and February 1998. Radiological followup consisted of renal ultrasound at approximately 3 to 6-month intervals with the addition of computerized tomography or magnetic resonance imaging (MRI) in patients with an indeterminate lesion(s) or nephrogenic rest(s). RESULTS: A total of 29 patients were identified. Of these cases renal ultrasound showed normal kidneys bilaterally in 19 (70%), simple cysts in 5 (19%), indeterminate lesion(s) in 2 (7%) and nephrocalcinosis in 1 (4%). Nephrogenic rests were followed with MRI in 1 patient, and 1 in whom a 2 cm. mass was revealed by followup MRI underwent partial nephrectomy and chemotherapy for stage I Wilms tumor. CONCLUSIONS: The 3.7% incidence of Wilms tumor in our patients with the Beckwith-Wiedemann syndrome is similar to that in previously published reports. Aggressive follow-up by a sensitive radiological technique is warranted in cases of the Beckwith-Wiedemann syndrome, and associated hemihypertrophy and/or nephromegaly with or without evidence of a Wilms tumor precursor. The detection of suspected malignant disease at an early stage may permit curative nephron sparing surgery.     

Microsporidia infection in transplant patients

BACKGROUND: Microsporidia are the most common cause of chronic diarrhea in patients infected with human immunodeficiency virus. Patients who have undergone organ transplantation may also be infected. The precise immune defect and the clinical picture in transplant patients have not been studied. METHODS: We report a case of microsporidia infection in a heart transplant patient and review three other cases reported in the literature. RESULTS: Infection in three solid organ transplant patients occurred when the patients were receiving immunosuppressive therapy for rejection 1.5-3 years after transplantation. Patients had chronic diarrhea, vomiting, dyspepsia, and weight loss for 1 month to 3 years. CONCLUSIONS: Microsporidia may be the cause of chronic unexplained diarrhea and gastrointestinal disturbances in transplant patients. Defects in cell-mediated immunity probably play a role in maintaining the chronicity of this infection. Specific screening requests should be made to the microbiology laboratory when microsporidia infection is suspected.     

Autoregulation of nitric oxide-soluble guanylate cyclase-cyclic GMP signalling in mouse thoracic aorta

1. The sensitivity of the soluble guanylate cyclase (sGC)-cyclic guanosine-3',5'-monophosphate (cyclic GMP) system to nitric oxide (NO) was investigated in mouse aorta from wild type (WT) and NO synthase (NOS) knockout (KO) animals. 2. The NO donor, spermine-NONOate (SPER-NO) was more potent in aortas from eNOS KO mice compared to WT (pEC50 7.30+/-0.06 and 6.56+/-0.04, respectively; n=6; P<0.05). In contrast, the non-NO based sGC activator, YC-1 was equipotent in vessels from eNOS WT and KO mice. The sensitivity of aortas from nNOS and iNOS KO animals to SPER-NO was unchanged. Forskolin (an adenylate cyclase activator), was equipotent in vessels from eNOS WT and KO animals. 3. The cyclic GMP analogue, 8-Br-cGMP was equipotent in eNOS WT and KO mice (pEC50 4. 38+/-0.04 and 4.40+/-0.05, respectively; n=5; P>0.05). Zaprinast (10-5 M) a phosphodiesterase type V (PDE V) inhibitor, had no effect on the response to SPER-NO in vessels from eNOS WT or KO mice. 4. The NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 3x10-4 M) increased the potency of SPER-NO in aortas from WT mice (pEC50 6. 64+/-0.02 and 7.37+/-0.02 in the absence and presence of L-NAME, respectively; n=4; P<0.05). 5. In summary, there is increased sensitivity of vessels from eNOS KO animals to NO. Cyclic AMP-mediated dilatation is unchanged, consistent with a specific up-regulation of sGC - cyclic GMP signalling. The functional activity of cyclic GMP-dependent protein kinase (G-kinase) and PDE V was also unchanged, suggesting that sGC is the site of up-regulation. These alterations in the sensitivity of the sGC - cyclic GMP pathway might represent a mechanism for the dynamic regulation of NO bioactivity.     

Synthesis, corticotropin-releasing factor receptor binding affinity, and pharmacokinetic properties of triazolo-, imidazo-, and pyrrolopyrimidines and -pyridines

The synthesis and CRF receptor binding affinities of several new series of N-aryltriazolo- and -imidazopyrimidines and -pyridines are described. These cyclized systems were prepared from appropriately substituted diaminopyrimidines or -pyridines by nitrous acid, orthoester, or acyl halide treatment. Variations of amino (ether) pendants and aromatic substituents have defined the structure-activity relationships of these series and resulted in the identification of a variety of high-affinity agents (Ki's < 10 nM). On the basis of this property and lipophilicity differences, six of these compounds (4d,i,n,x, 8k, 9a) were initially chosen for rat pharmacokinetic (PK) studies. Good oral bioavailability, high plasma levels, and duration of four of these compounds (4d,i,n,x) prompted further PK studies in the dog following both iv and oral routes of administration. Results from this work indicated 4i,x had properties we believe necessary for a potential therapeutic agent, and 4i1 has been selected for further pharmacological studies that will be reported in due course.     

Recombinant human gamma-interferon induces human monocyte polykaryon formation.

Monocyte or macrophage polykaryons (MP) are seen in different tissues in various inflammatory states and in normal bone (osteoclasts). The factors controlling the formation and the function of MP are not completely understood. This study was designed to evaluate the effects of the lymphokine gamma-interferon (IFN-gamma) on human monocyte function in vitro. Purified recombinant IFN-gamma [20-200 units/ml (0.1-1.0 nM)] caused the appearance of MP in cultures of normal human monocytes cultured in 10% unheated autologous serum. The MP were noted by as early as 36 hr of culture with fusion indices of 40%-60% and up to 160 nuclei per cell. The effect was seen with both recombinant IFN-gamma and natural IFN-gamma produced by Staphylococcal enterotoxin A-stimulated lymphocytes, but IFN-alpha (leukocyte-derived and recombinant) and IFN-beta did not induce MP formation. The activity of the IFN-gamma was destroyed by heating at 56 degrees C for 4 hr, incubating at pH 2 for 3 hr, or incubating with antibody against IFN-gamma. Populations of monocytes incubated 3 days with 100 units of IFN-gamma per ml (0.5 nM) had enhanced capacity to produce H2O2 in response to phorbol 12-myristate 13-acetate and increased content of acid phosphatase and plasminogen activator. As determined by autoradiography, the MP did not incorporate [3H]dThd into their nuclei. Thus, the IFN-gamma appears to induce MP formation by a process of monocyte fusion, and to "activate" monocytes, as judged by various parameters.