Pharmacodynamic approach to study the gene transfer process employing non-viral vectors

In the present work we set out to apply pharmacodynamic concepts derived from dose-response curves (Potency and Efficacy) to characterize the gene transfer efficiency of a vector:DNA complex. We employed two widely used vectors, the cationic lipid DOTAP (N,N, N-trimethyl 1-2-3-bis (1-oxo-9-octa-decenyl)oxy-(Z, Z)-1-propanaminium methyl sulfate) and the cationic polymer PEI (polyethylenimine, 800 kDa) to transfect several constructions of the green fluorescent protein cDNA. The analysis of dose-response curves indicated that in all cases the goodness-of-fit was > 0.99. Potency is a measure that provides information on gene activity per amount of DNA. Efficacy is a measure of maximum gene expression achievable using a specific vector:DNA complex, and depends on both the intrinsic efficacy of the gene (evaluated using different vectors to transfer the same gene construct) and on vector efficacy in DNA delivery (evaluated using a single vector to deliver different gene constructs). The results suggest that Potency and Efficacy are objective parameters for describing and comparing the goodness of vectors, as well as the intrinsic efficacy of a given gene construct. Furthermore, they are useful tools that may contribute to a better understanding of the mechanistic gene transfer process of each vector.

Indirect induction of suppressor of cytokine signalling-1 in macrophages stimulated with bacterial lipopolysaccharide: partial role of autocrine/paracrine interferon-alpha/beta

It has previously been reported by us that a brief prior exposure of mouse bone marrow culture-derived macrophages to bacterial lipopolysaccharide (LPS) resulted in a dramatic reduction in their ability to produce NO in response to a subsequent stimulus with either interferon-gamma (IFN-gamma) or IFN-gamma plus LPS. We show here that this brief exposure to LPS results in an impaired response to subsequently added IFN-gamma. A 2--4 h pretreatment with LPS leads to a dramatic reduction in the IFN-gamma-induced DNA-binding of the transcription factor, signal transducer and activator of transcription 1 alpha (STAT1 alpha). This loss in ability to activate STAT1 alpha temporally correlates with the LPS-induced accumulation of mRNA encoding the suppressor of cytokine signalling-1 (SOCS-1). However, LPS does not directly induce the synthesis of SOCS-1. Rather, LPS induces the synthesis of autocrine/paracrine factors that are the true mediators of SOCS-1 induction. IFN-alpha/beta is one of these mediators, but plays only a partial role in the induction of SOCS-1 because neutralization of LPS-induced IFN-alpha/beta production incompletely inhibits the induction of SOCS-1. We show that mouse IFN-beta directly induces the synthesis of SOCS-1, without the need for prior protein synthesis, and does so with faster kinetics than does LPS. Our results are consistent with the non-specific nature of LPS-induced tolerance and provide a mechanistic insight into nonspecificity; LPS indirectly induces the synthesis of a protein mediator, SOCS-1, which inhibits the signalling that is induced by IFN-gamma.

Prolonged exposure of mouse macrophages to IFN-beta suppresses transcription of the inducible nitric oxide synthase gene: altered availability of transcription factor Stat1alpha

Previous studies from our laboratory have shown that prolonged exposure of mouse macrophages to IFN-beta interferes with their subsequent ability to become activated for tumor cell killing. Data reported here show that such inhibition is due to reduced production of NO, resulting from decreased transcription of the gene that encodes inducible NO synthase (iNOS; EC 1.14.13.39). The molecular basis for such suppression was shown to be, at least in part, decreased nuclear accumulation of tyrosine-phosphorylated Stat1alpha (pStat1alpha), and a consequent change in the nuclear ratio of pStat1alpha to non-transactivating pStat1beta. Reduced phosphorylation was observed despite the fact that time-course studies revealed greater than normal quantities of both Stat1alpha and Stat1beta proteins in macrophages that had been pre-exposed to IFN-beta. The decrease in nuclear pStat1alpha was demonstrated to involve an increase in the rate of turnover of phosphorylated protein. The homodimeric form of pStat1alpha is essential for the expression of both the iNOS and IFN-regulatory factor-1 genes (the product of the latter is necessary for full expression of the iNOS gene). These results have broad implications, because they suggest that limiting the availability of homodimeric pStat1alpha is a means by which down-regulation of genes containing promoter-linked IFN-gamma-activated sites might be achieved.

Terminal-sequence conservation identifies spliceosomal introns in ascomycete 18S RNA genes

Twenty-four new insertions were obtained from seven different locations in the nuclear 18S rDNA for seven species of the lichen-forming fungal genus PHYSCONIA: They were analyzed allowing for terminal sequence conservation by adopting a flexible approach to exact insertion site position, and they were compared with 12 previously reported small insertion sequences from the 18S ribosomal RNA gene. Such insertions have previously been proposed to be degenerate self-splicing group I introns; however, the methodology used here identified consensus terminal sequences characteristic of spliceosomal introns. This finding is the first suggestion that multiple spliceosomal introns occur in ribosomal genes.

Effect of hydrocortisone on platelet activating factor induced lung edema in isolated rabbit lungs

The effect of hydrocortisone on platelet activating factor (PAF)-induced pulmonary edema is studied. Thirty four isolated and perfused rabbit lung preparations were used: eight control preparations, eight PAF preparations with two doses of PAF called low dose (LD = 0.5 microg/kg of rabbit weight) and high dose (HD = 1 microg/kg of rabbit weight). Eighteen preparations divided in three groups of six were pretreated with doses of 20, 200 and 2000 mg of hydrocortisone and later given the same doses of PAF as described above. Hydrocortisone significantly decreased (P < 0.05) the effect of PAF LD over the pulmonary arterial pressure (Ppa) in the 200 and 2000 mg groups (58 and 89% decrease, respectively) and it significantly decreased (P < 0.05) the effect of PAF HD over Ppa in all hydrocortisone pretreated groups (48, 70 and 96% decrease, respectively). Fluid filtration rate (FFR) increases mediated by PAF HD were significantly inhibited (P < 0.05) in the 200 and 2000 mg groups (64 and 96% decrease, respectively). We conclude that hydrocortisone inhibits the effect of PAF over the pulmonary circulation.

Pharmacokinetics of oligodeoxynucleotides encapsulated in liposomes: effect of lipid composition and preparation method

1. The effect of the method employed to prepare liposomes and their lipid composition were evaluated in terms of the encapsulation efficiency and pharmacokinetic features of two oligodeoxynucleotides of a 21 mer: the normal (N-Odn) and the phosphorothioate (S-Odn) oligodeoxynucleotide. 2. Liposomes were prepared by the classical method of multilamellar vesicles (MV) and by the dehydration-rehydration method (DR). Two lipid mixtures were used to prepare liposomes--the predominant lipid being phosphatidylcholine (PC) and sphingomyelin (SM) respectively. 3. The DR method for liposome preparation provided the highest encapsulation efficiency, regardless of liposome lipid composition and the type of oligodeoxynucleotide involved (N-Odn or S-Odn). 4. The pharmacokinetics of free and liposome encapsulated oligodeoxynucleotides was studied in mouse following i.v. administration. Liposome encapsulated oligodeoxynucleotides exhibited a significantly lower plasma clearance and longer half-life and residence time than free oligodeoxynucleotides. The method used to obtain the liposomes affected plasma clearance, which was lower for liposomes elaborated by the DR method than for liposomes prepared with the MV method. The use of S-Odn in place of N-Odn decreased the plasma clearance of oligodeoxynucleotide when administered encapsulated in liposomes, regardless of the lipid composition and method used to obtain the liposomes.

[Value of Pet-18FDG in lung cancer]

INTRODUCTION

18FDG-PET was studied in the diagnosis of malignancy of the solitary pulmonary nodule and in the early staging of non-small-cell lung cancer. PET results were compared with thoracic-abdominal computed tomography (CT) and brain magnetic resonance (MR).

PATIENTS AND METHODS

Fifty-five patients with a radiologically detected solitary pulmonary nodule (54 CT, 1 plain radiography), were studied following an intravenous injection of 370 MBq 18FDG. Attenuation corrected emission data were acquired and analyzed qualitatively and semi-quantitatively. 30 non-small-cell lung cancer underwent MR. Biopsies were obtained in 48 non-small-cell lung cancer and 7 were controlled by follow-up (18 months). The staging of 43 non-small-cell lung cancer was confirmed by surgery (n = 13), mediastinoscopy (n = 9) and follow-up (n = 21).

RESULTS

PET correctly diagnosed 52 solitary pulmonary nodules with 3 false positives (100% sensitivity and 75% specificity). In the mediastinal staging (N), CT and PET demonstrated a sensitivity and specificity of 46% vs. 100%, and 59.3% vs. 93.3%, respectively. In 6 patients, some visceral metastases detected by PET were not detected by CT (including 3 adrenals), whereas 2 brain metastases in MR were not diagnosed by PET. PET was considered decisive in the treatment and follow-up of 17 patients (32.7%).

CONCLUSIONS

Whole body PET imaging is a cost-effective diagnostic technique that simplifies the malignant characterization of solitary pulmonary nodule and improves the early staging of non-small-cell lung cancer. In combination with CT, PET makes an outstanding contribution to the correct assessment of therapeutical decisions in these patients.

[Congenital cyanotic heart disease and peripheral neurogenic tumor]

The association between neuroblastic tumours and congenital heart disease is widely confirmed in the literature references. The authors describe a case of a patient with congenital heart disease, high blood pressure, renal artery stenosis and high levels in 24 hours urine metanephrines. A MIBG-I-123 scintigraphy was essential for the diagnosis of neuroblastic tumour.

Effect of the protein kinase inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine H-7 and N-(2-[methylamino]ethyl)-5-isoquinoline-sulfonamide H-8 on Lewis lung carcinoma tumor progression

The effects of 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine H-7 (a cAMP-dependent protein kinase and protein kinase C inhibitor), n-(2-[methylamino]ethyl)-5-isoquinoline-sulfonamide H-8 (a cAMP- and cGMP-dependent protein kinase inhibitor) and indomethacin (IND, a cyclooxygenase inhibitor) on both the spontaneous metastatic ability of 3LL (Lewis lung carcinoma) tumor cells and anti-tumor host response were studied. The study of tumor progression showed that H-7 and H-8 (2 mg kg(-1) day(-1) , i.p., for 8 days) significantly reduced the mean number of metastases (0.8 +/- 0.2 and 1.0 +/- 0.7, respectively, P < 0.05) with respect to the number of lung metastases (4.2 +/- 2.1) observed in the control group. In turn, the highest tumor-specific cytotoxicity response (50% increase vs. non-treated target cells) was observed when both animal and tumor cells were treated with H-8. This suggests that the protein kinase inhibitors could inhibit tumor progression toward lung metastases formation by blocking the immunosuppressor mechanism triggered by agents that increase intracellular cAMP.

[Non-Hodgkin's lymphoma with heart disease in patients with AIDS: clinical and echocardiographic aspects]

We report two patients with AIDS and non-Hodgkin lymphoma evolving myocardium. Clinical findings were nonspecific, but rapid progression and cardiac dysfunction developed. An echocardiogram showed restrictive pericarditis in both cases. One of them showed mitral insufficiency because of an infiltrated and trapped posterior mitral valve.

The diagnostic value of Tc-99m human polyclonal immunoglobulin imaging compared to Tc-99m HMPAO labeled leukocytes in inflammatory bowel disease

The aim of this study was to establish the usefulness of Tc-99m human polyclonal immunoglobulin (HIG) imaging in a group of patients who were suspected of having inflammatory bowel disease (IBD). The authors performed 30 scans (15 with Tc-99m HMPAO leukocytes and 15 with Tc-99m HIG) on 15 patients with IBD. Ten patients had Crohn's disease and five had ulcerative colitis. The sensitivity of Tc-99m HIG scintigraphy for detecting IBD was 33%, while the sensitivity of Tc-99m HMPAO leukocyte imaging was 100%. The Tc-99m HMPAO leukocyte imaging also detected a larger number of affected segments and provided better image quality of the extent of disease than Tc-99m HIG. On the basis of these results, the authors believe that Tc-99m HIG imaging is not a useful technique in the evaluation of patients with IBD, in the identification of location, or the extension or degree of disease activity.

Protection of rat myocardium by mitogenic and non-mitogenic fibroblast growth factor during post-ischemic reperfusion

The effects of acidic fibroblast growth factor (FGF-1) and basic fibroblast growth factor (FGF-2) and a non mitogenic form of FGF1 on myocardial ischemia and reperfusion were assessed. Rats underwent 10 minutes of coronary artery occlusion followed by 24 hours of reperfusion. Creatinine kinase content of the affected myocardium showed that both fibroblast growth factors 1 and 2 effectively protected against ischemia reperfusion injury (p < 0.01), and that the vasoactive but nonmitogenic form of the FGF1 was equally protective (p < 0.01 versus control + vehicle). The results were confirmed by light and electron-microscopy histological studies. Histological evaluations after treatment with the non-mitogenic fibroblast growth factor 1 showed that it did not generate the severe hyperplasia and connective tissue disorganization observed with the native mitogenic proteins. The possibility of using a non-mitogenic form of fibroblast growth factor for cardio-protection circumvents many of the potentially undesirable effects that may derive from systemically introducing broad spectrum acting fibroblast growth factors in vivo. This myocardial protection observed 24 hours after the treatment with fibroblast growth factors, and the efficacy of the non-mitogenic form of the protein, also suggest that the protective effect of fibroblast growth factors may be due to the increased blood flow rather than to angiogenesis.

Anti-interleukin 4 antibody and indomethacin synergistic effect on B16 melanoma tumor progression

B16 melanoma-bearing mice were treated with anti-interleukin 4 antibody, indomethacin or its combination to evaluate the ability of the primary tumor to induce lung metastasis and the antitumor host response. Flow cytometry of tumor cells incubated with sera from tumor-bearing mice showed B16 melanoma to induce a significant antitumor humoral response (39.0 +/- 1.1% positive cells versus 1.8 +/- 0.9% in the control). The treatment of tumor-bearing mice with antimouse anti-interleukin 4 monoclonal antibody plus indomethacin significantly increased (P < .01) the mean value of lung metastasis (from 6.1 +/- 3.0 in the controls to 50.8 +/- 21.8). Also, a significant increase in natural cytotoxicity against tumor cells was observed when both peripheral blood mononuclear cells and splenocytes were used as effector cells. In contrast, an antibody-dependent cellular cytotoxicity decrease was found with effector cells from both normal and tumor-bearing mice. In the former, the antibody-dependent cellular cytotoxicity decrease was 49.4% and 58.4% (P < .05) for peripheral blood mononuclear cells and splenocytes, whereas in the second case the decrease was 40.7% (P < .05) and 29.1% (P < .01), respectively. These results suggest that an efficient antibody-dependent cellular cytotoxicity response might be necessary to secure an effective host antitumor immune response.

Long-term expression of the human alpha1-antitrypsin gene in mice employing anionic and cationic liposome vectors

The efficiency of both anionic and cationic liposomes as vectors for in vivo human alpha1-antitrypsin (AAT) gene transfer was studied in mice with and without an associated partial hepatectomy. The pTG7101 plasmid, containing the full-length human AAT gene, was encapsulated in small liposomes bearing 10% of negatively (phosphatidylserine, PS) or positively (DOTAP) charged lipids. The results indicated that the DNA/lipid ratio was increased in cationic liposomes by inclusion of monosialoganglioside-GM1. The expression of human protein after in vivo gene transfer was quantified in mouse plasma by an ELISA procedure, and revealed that both anionic and cationic liposomes mediated the presence of human protein in mouse plasma for 2-3 weeks. This effect was prolonged (>5 months) when a partial hepatectomy was performed after treatment. In addition, it was observed that the efficacy of liposome-mediated gene transfer was more limited when the plasmid was externally associated to cationic liposomes.

Scintigraphic diagnosis of subclinical Cushing's syndrome in patients with adrenal incidentalomas

Adrenal scintigraphy has been shown to be a useful procedure for the characterization of incidentally discovered adrenal tumours. The functional evaluation of these patients is controversial. This paper describes the biochemical and pathological findings in five patients with asymptomatic adrenal masses and unilateral concordant adrenocortical scintigraphic uptake. All the patients were diagnosed as having subclinical Cushing's Syndrome, without clinical or biochemical adrenocortical dysfunction. Scintigraphy is the most sensitive method for detecting an adrenal adenoma in the subclinical setting when the disease is not yet demonstrable by biochemical methods.

Nucleolar organizer region (NORs) in pseudocarcinomatous hyperplasia and squamous cell carcinoma of the oral mucosa

Counts of nucleolar regions (NORs) demonstrated by a silver staining technique in paraffin sections, have been used to distinguish benign from malignant lesions. AgNORs were studied in 24 biopsies from oral cavity (5 cases of normal oral mucosa, 5 of pseudocarcinomatous hyperplasia and 14 of squamous cell carcinoma, subdivided according to degree of differentiation: 5 grade 1, 5 grade 2 and 4 grade 3) to find whether they were helpful in distinguishing pseudocarcinomatous hyperplasia due to chronic parasitic infections from squamous cell carcinoma. Two methods of counting AgNORs were used: (A) a simpler one which counts nucleolar clusters (AgNU) and satellite AgNORs and the other (B) counting all individual AgNORs, including those within AgNUs. In both methods the lowest mean values were observed for grade 3 carcinoma, while the highest belonged to grade 2 carcinoma. The simpler method (A) was the most useful because AgNU counts showed significant difference when pseudocarcinomatous hyperplasia was compared with grade 1 and 2 carcinomas, which are the most difficult to discriminate from it. However the overlapping of values render the technique of limited use in individual cases.

Use of scanning cytometry in studying bradykinin binding in MRC-5 cells

Ligand-receptor affinity is classically demonstrated by measuring ligand binding density to a specific site on membrane preparations, and receptor function is studied by measuring calcium flux, cell by cell, using microspectrofluorimetry. In order to study these phenomena in a large cell population, calcium flux was measured in MRC-5 cell line expressing the B2 receptor for bradykinin using an ACAS 570 scanning cytometer. Following incorporation of fluo3/AM, different ligands were studied, singly or in association with bradykinin. This study confirmed that only the B2 receptor is present on the plasma membrane of MRC-5 cells. Bradykinin binding to the B2 receptor was not modified by a B1 agonist (Des-Arg9-bradykinin) or by a B1 antagonist (Des-Arg9-[Leu8]-bradykinin) but was inhibited by a B2 agonist ([Hyp3]-bradykinin) and a B2 antagonist (HOE 140). The source of free calcium was also studied in comparison with ionomycin. The intensity of the calcium peak after binding of bradykinin is independent of the concentration of extracellular calcium. Preincubation with diltiazem or TMB-8 did not modify calcium flux, indicating that transduction of the signal after bradykinin binding in this cell line is independent of voltage-dependent channels and does not require mobilization of intracellular calcium blocked by TMB-8. In conclusion, scanning cytometry can be used to study ligand-receptor binding and to obtain results rapidly from multiple cells. Recording of individual cell variations and kinetics enables identification of active agonists or antagonists and consequently the selection of new compounds.

Expression of human alpha 1-antitrypsin in mouse after in vivo gene transfer to hepatocytes by small liposomes

A plasmid (pTG7101) containing the full-length human alpha 1-antitrypsin gene was encapsulated in small liposomes and used for "in vivo" gene transfer to mouse hepatocytes, by i.v. injection (100 ng DNA/mouse and dose). The expression of human protein was evaluated by microspectrophotometry after human alpha 1-antitrypsin immunoperoxidase reaction on liver cryosections and the presence in mouse plasma of de novo synthesized protein was detected by ELISA analysis. Our results indicate that a single dose of encapsulated plasmid induces the expression of human alpha 1-antitrypsin in mouse hepatocytes and a large effect (70%) remains two weeks after treatment. However, no effect was observed when mice were treated with buffer or free plasmid (100 ng/mouse) plus an equivalent lipid dose of empty liposomes. In addition, whereas no additive effect was observed after repetitive treatment-doses, the partial hepatectomy three hours after a single treatment-dose, significantly increased the presence of human alpha 1-antitrypsin in mice plasma.

A case of complete Carney's syndrome

The triad of gastric leiomyoblastoma, paraganglioma, and pulmonary chondroma was first described by Carney in 1977. The authors report a case of a patient with gastric leiomyosarcoma, multiple pulmonary chondromata, and paraganglioma. This represents a complete form of Carney's triad. The paraganglioma was identified with I-123 MIBG.

Differential diagnosis of solid adrenal masses using adrenocortical scintigraphy

To evaluate the diagnostic contribution of adrenal scintigraphy with 75-Se-selenomethylcholesterol in adrenal masses, 42 patients have been studied. All of them had a solid adrenal mass discovered on computed tomography (seven bilateral). None of the patients showed any symptoms or clinical signs that might indicate the existence of adrenal dysfunction. Twenty-nine of them had known extra-adrenal primary malignant disease. Forty-nine adrenal tumours were detected with an average size of 3.29 cm (range 1.5-12 cm). Eighteen lesions showed increased uptake of radiocholesterol on the side of the adrenal mass, all of which were either proven to be benign, or behaved in a benign fashion. Twelve lesions showed normal uptake (10 in the benign group and one lung carcinoma metastasis), all but one (2.5 cm) being smaller than 2 cm. Decreased uptake was observed in 20 lesions (15 metastases, two nonfunctional adrenal carcinomas, one myelolipoma and two tuberculous infectious lesions). Adrenocortical scintigraphy provides functional information about adrenal masses and is useful in differentiating between benign and malignant lesions.

The human galanin receptor: ligand-binding and functional characteristics in the Bowes melanoma cell line

The human galanin receptor has been characterized pharmacologically from the Bowes melanoma cell line. Using porcine [125I]galanin as the radioligand, a single population of non-interacting high-affinity binding sites (KD = 0.05 +/- 0.01 nM; Bmax = 135 +/- 7 fmol/mg protein) was demonstrated. Human galanin peptide competitively inhibited the specific binding of [125I]galanin (IC50 = 0.35 +/- 0.13 nM) and decreased the forskolin-stimulated cAMP production (EC50 = 0.46 +/- 0.05 nM) with a maximal inhibition of 63 +/- 2% at 10(-7) M. Rat and porcine galanin peptides and the chimeric peptides M15, M35, M32, M40 and C7 also dose-dependently inhibited the forskolin-stimulated cAMP production, while the fragment porcine galanin-(3-29) and [D-Trp2]galanin were found to be inactive. The specific binding of [125I]galanin was decreased in a dose-dependent manner by GTP and the cAMP response was inhibited by the pertussis toxin, suggesting the activation of a G-protein dependent process. The Bowes cell line thus appears to be a relevant tool for the study of human galanin receptor.

MCA Serum Determination in Breast Carcinoma Patients for the Diagnosis of Bone Metastases

Serum MCA levels were determined in 173 consecutive patients with breast cancer in order to assess the clinical utility of MCA for the detection of bone metastases. Bone pathology was diagnosed by scintigraphy, radiology and clinical follow-up. Metastases were found in 37 patients, benign lesions in 25, and in 111 no bone lesions were found. Eighteen of the 173 bone scans were considered indeterminate for metastases. Based on the receiver-operating characteristic curves (ROC) analysis, the cut-off level for MCA was set at 20 U/ml. Only in 4 of the 37 patients with bone metastases MCA was below 20 U/ml. All 4patients had completed their chemotherapy course within six months before MCA determination. Only in 6 patients of the 136 without bone metastases MCA levels were above 20 U/ml. Of the 18 patients with indeterminate bone scans, 15 had benign lesions and all of them had MCA levels below 20 U/ml.

MCA determination is a sensitive method for the detection of bone metastases in breast carcinoma. We encourage the use of this procedure for the selection of high-risk groups or as a complementary method for the interpretation of bone scintigraphy.

MCA serum determination in breast carcinoma patients for the diagnosis of bone metastases

Serum MCA levels were determined in 173 consecutive patients with breast cancer in order to assess the clinical utility of MCA for the detection of bone metastases. Bone pathology was diagnosed by scintigraphy, radiology and clinical follow-up. Metastases were found in 37 patients, benign lesions in 25, and in 111 no bone lesions were found. Eighteen of the 173 bone scans were considered indeterminate for metastases. Based on the receiver-operating characteristic curves (ROC) analysis, the cut-off level for MCA was set at 20 U/ml. Only in 4 of the 37 patients with bone metastases MCA was below 20 U/ml. All 4 patients had completed their chemotherapy course within six months before MCA determination. Only in 6 patients of the 136 without bone metastases MCA levels were above 20 U/ml. Of the 18 patients with indeterminate bone scans, 15 had benign lesions and all of them had MCA levels below 20 U/ml. MCA determination is a sensitive method for the detection of bone metastases in breast carcinoma. We encourage the use of this procedure for the selection of high-risk groups or as a complementary method for the interpretation of bone scintigraphy.

Single topical application of human recombinant basic fibroblast growth factor (rbFGF) promotes neovascularization in rat cerebral cortex

Basic fibroblast growth factor (bFGF) is a morphogenic, chemotactic, mitogenic, and angiogenic peptide found within the central nervous system (CNS) with potent neurotrophic effects. A potential role in ischemia-induced vascular growth has been suggested for bFGF. In this study, we show that single, topical administration of human recombinant basic fibroblast growth factor (rbFGF) in the rat cerebral cortex promotes capillary overgrowth and might mimic the angiogenic response observed after brain ischemia. The implication of this finding for the therapeutic use of basic FGF in angiogenic therapy is discussed.

Diabetic foot infections: scintigraphic evaluation with 99Tcm-labelled anti-granulocyte antibodies

Thirty-eight lesions found by physical and/or radiological examination in 25 patients with long-term diabetes mellitus were studied in order to evaluate the clinical utility of immunoscintigraphy using 99Tcm-labelled anti-granulocyte monoclonal antibodies (MAb BW 250/183) for the diagnosis of infectious pathology in diabetic foot. All the patients underwent three-phase bone scintigraphy with 740 MBq 99Tcm-methylene disphosphonate. Immunoscintigraphy was performed 4 and 24 h after administration of 500 MBq of the labelled antibody by planar selective views. Uptake intensity was scored 0 to 4 (0 = normal, 1 = mildly increased, 2 = moderately increased, 3 = intense, 4 = very intense) when compared with adjacent or contralateral uninvolved bone marrow and soft tissue. Several projections were performed and anatomical references of bone scan were used to determine whether the lesion involved the bone or soft tissue. Definitive diagnoses were 15 osteomyelitis, 14 soft tissue lesions (nine cellulitis and five noninfected ischaemic or trophic wounds), and nine degenerative bone disease. 99Tcm-granulocyte scintigraphy showed increased uptake in seven soft tissue lesions, in four of which exclusively soft tissue involvement was demonstrated by scintigraphy. Only one false negative scintigraphic finding was observed (chronic osteomyelitis). No abnormal anti-granulocyte antibody uptake was observed in degenerative lesions. Based on our observations, immunoscintigraphy with 99Tcm-MAb BW250/183 has a sensitivity of 93% in the diagnosis of osteomyelitis involving diabetic patients' feet. Although it is feasible to distinguish exclusive soft tissue involvement, this is still the main cause of misdiagnosis in current clinical practice.

Characterization of a human NK1 tachykinin receptor in the astrocytoma cell line U 373 MG

The human NK1 tachykinin receptor in the astrocytoma cell line U 373 MG was characterized using selective agonists and antagonists described for this receptor in the rat. Specific [3H]substance P binding sites were present on cell homogenates, whereas [3H]neurokinin A or [3H]-senktide binding sites were absent. The binding was saturable and reversible. The binding of [3H]substance P was inhibited by very low concentrations of [L-Pro9]substance P and [Sar9,Met(O2)11]substance P; septide was approximately 1,000-fold less potent. The most potent peptide antagonist was trans-4-hydroxy-1-(1H-indol-3-ylcarbonyl)-L-prolyl-N-methyl-N-(phe nylmethyl)-L- tyrosineamide. The rank order of potency for the nonpeptide antagonists was (S,S)-CP 96,345 > (+/-)-CP 96,345 > (+/-)-2-chlorobenzylquinuclidinone > (R,R)-CP 96,345 > RP 67580 > RP 68651. In [3H]-inositol-labeled cells, substance P stimulated phosphatidylinositol turnover. A good correlation was found when the abilities of NK1 receptor agonists for stimulating inositol phosphate production and for inhibiting [3H]substance P binding were compared. Similarly, the binding and functional assays were well correlated for the antagonists. As a result of its high sensitivity and selectivity, the U 373 MG cell line thus appears an excellent tool for investigating the pharmacology of the human NK1 receptor.

[Electroencephalographic effects of subhypnotic doses of midazolam in healthy subjects and in brain disease patients]

The aim of this study was to analyze the electroencephalographic alterations produced by minimum doses of midazolam and look for a theoretic base for these changes in the benzodiazepinic receptor. To do so, the possible abnormal responses provoked by midazolam on the EEG of patients with ischemic cerebral infarctions were studied. Sub-hypnotic infusions of midazolam (0.15 mg kg/min) were administered prior to anesthetic induction in three groups of patients: control group, patients with tumoral cerebral pathology group, and ischemic cerebral infarctions group. In addition to the known modifications obtained in the patients of the control group, those presenting bioelectric activity alterations due to tumoral pathology did not show modifications. In the group of patients with ischemic infarctions, the intravenous perfusion of midazolam induced moderate increase in the localized theta and delta frequency and a lower representation of the beta rhythm which was also of lower amplitude. Midazolam is capable of making slow rhythms on the EEG, following it administration at low doses, in ischemic zones of the brain.

Interleukin-1 beta-specific partial agonists defined by site-directed mutagenesis studies

Monocyte-derived interleukin 1 (IL-1) mediates a wide range of biological effects including destruction of the cartilage matrix in articular diseases such as rheumatoid and osteoarthritis. To elucidate further the relationships between protein structure and biological activities, we have analyzed the sequence of several IL-1 polypeptides using the algorithm of Parker, the hydrophobic cluster analysis method and published structural data. This led us to identify several residues that seemed to be strictly topologically conserved, with respect to identifiable secondary structures features, although this was not readily apparent from sequence alignments. We performed site-directed mutagenesis on some of these conserved residues, as well as on those predicted to occur in external loops of the polypeptide. Human IL-1 beta mutant polypeptides were expressed in Escherichia coli in soluble form and purified to homogeneity by anion-exchange and gel-filtration chromatography. Their biological effects (binding to EL4-6.1 murine thymocytes, Raji human B cells and rabbit chondrocytes cells, lymphocyte activation, neutral protease induction, proteoglycan degradation and synthesis) have been determined. Among the 20 IL-1 beta mutant polypeptides we present here, four showed a markedly reduced activity in cartilage matrix assays without any significant change in their binding to the cartilage matrix cells (chondrocytes). Furthermore, some of these mutants were specific partial agonists of the effects of IL-1 on connective tissue since they have a low affinity for thymocytes.

Monoclonal antibodies against synovial collagenase: use for immunopurification and characterization of the latent and active enzyme

Monoclonal antibodies have been produced against porcine synovial collagenase which recognize both the active enzyme and its inactive precursor. These antibodies inhibited the collagenolytic activity of collagenase, but not its activity with a synthetic peptide substrate. The antibodies were also able to recognize human synovial, human skin fibroblast and human chondrocyte collagenase but not the enzyme from human granulocytes. One of the monoclonal antibodies was successfully used for the immunopurification of the porcine enzyme and these experiments led to the demonstration of an endogenous activator of procollagenase in the synovial cell culture medium.

Localization of a neutralization epitope of foot-and-mouth disease virus using neutralizing monoclonal antibodies

Neutralizing monoclonal antibodies raised against intact foot-and-mouth disease virus reacted with intact particles and with isolated VP1 from different strains from the same subtype. Prior treatment of the virus with either trypsin or with arginine-specific protease abolished recognition of both the virus and of VP1, suggesting the presence of a neutralization epitope in the central region of VP1 cleaved by these two enzymes. A synthetic peptide analogue of part of this region showed poor reactivity, however, with neutralizing antibody.

Regulation of energy metabolism in Trypanosoma (Schizotrypanum) cruzi epimastigotes. I. Hexokinase and phosphofructokinase

Hexokinase (ATP: hexose 6-phosphotransferase, E.C.2.7.1.1) and phosphofructokinase (ATP:fructose-6-phosphate 1-phosphotransferase, E.C.2.7.1.11), two key regulatory enzymes of the glycolytic pathway in vertebrate cells, have been isolated and partially purified from Trypanosoma (Schizotrypanum) cruzi epimastigotes. Both enzymes are associated with particles sedimentable at 105 000 X gav for 1 h and have a high degree of latency; they can be solubilized by sonication. Hexokinase catalyses the phosphorylation of a series of monosaccharides at the following relative rates: D-glucose (100) congruent to D-fructose (97) greater than 2-deoxy-D-glucose (72) congruent to mannose (69) greater than 2-amino-D-glucose (63) greater than 3-O-methyl-D-glucose (21). Very little or no phosphorylating activity was found for D-galactose, N-acetyl-2-amino-D-glucose or 1-alpha-methyl-D-glucose. D-Glucose phosphorylation at fixed ATP concentration follows simple Michaelis-Menten kinetics with Km = 40 microM and Vmax = 440 nmol min-1 mg-1 protein. D-Mannose, 2-deoxy-D-glucose and N-acetyl-2-amino-D-glucose act as competitive inhibitors of glucose phosphorylation, suggesting a single kinase. Mg2+-ATP is the preferred phosphoryl donor, ITP and GTP being much less effective. T. cruzi hexokinase is not inhibited by D-glucose 6-phosphate, or by any of the following compounds (2 mM):D-fructose 6-phosphate, D-fructose 1,6-diphosphate, D-glucose 1,6-diphosphate, phosphoenol pyruvate, L-malate and citrate. Phosphofructokinase displays simple Michaelis-Menten kinetics with no evidence of sigmoidicity with respect to D-fructose 6-phosphate at all ATP concentrations tested, giving a Km of 1.31 mM and Vmax = 400 nmol min-1 mg-1 protein at optimal ATP levels. With respect to ATP, the enzyme exhibits Michaelis-Menten kinetics at low concentration (less than 1 mM) of the substrate (Km = 40 microM at 5 mM MgCl2, pH 7.4). A moderate inhibition is observed at high ATP levels (70% of maximal activity at 2 mM). GTP can substitute for ATP as the phosphoryl donor (Km = 79 microM under the same conditions), but produces only very small inhibitory effects at high concentrations. 5'-AMP activates the enzyme by decreasing its Km with respect to D-fructose 6-phosphate without affecting Vm. Other well-known regulators of the activity of this enzyme in procaryote and vertebrate systems such as citrate, phosphoenol pyruvate, ammonium and phosphate ions have no effect in T. cruzi.

Sobre las comunidades terrícolas de líquenes vagantes (Sphaerothallio-Xanthoparmelion vagantis Al. Nova)

Se propone una nueva alianza Sphaerothallio-Xanthoparmelion vagantis, de líquenes errantes de lugares fisiológicamente áridos (termo o crioáridos), por continentalidad o desertización higrotérmica fuertemente venteados y entrofos. En el seno de esta alianza describimos una nueva asociación Sphaerothallietum fruticulosofoliaceae que se desarrolla, en España, en el piso de vegetación ibérico de paramera en los claros de las comunidades de tomillar-pradera de Festuco-Poion ligulatae, entre 1.200-1.400 m. de altitud y que, sin duda, supera el ámbito de la Región Mediterránea, encontrando tal vez un óptimo en la Irano-Turánica. Datos bibliográficos nos hacen deducir su presencia en las montañas de Astrakan, y Tauria (Rusia). Se incluye también en la alianza la asociación Parmelietum vagantis (Keller 1938) Klement 1955 enmendándola profundamente. Discutimos en el trabajo las comunidades afines a las descritas, en base a conceptos florísticos y ecológicos (Diploschistion terrestris Klement 1955 y Parmelietum vagantis (Keller 1938) Klement 1955.