Interaction of cationic porphyrins with DNA: importance of the number and position of the charges and minimum structural requirements for intercalation

Thirty-three porphyrins or metalloporphyrins corresponding to the general formula [meso-[N-methyl-4(or 3 or 2)-pyridiniumyl]n(aryl)4-nporphyrin]M (M = H2, CuII, or ClFeIII), with n = 2-4, have been synthesized and characterized by UV-visible and 1H NMR spectroscopy and mass spectrometry. These porphyrins differ not only in the number (2-4) and position of their cationic charges but also in the steric requirements to reach even temporarily a completely planar geometry. In particular, they contain 0, 1, 2, 3, or 4 meso-aryl substituents not able to rotate. Interaction of these porphyrins or metalloporphyrins with calf thymus DNA has been studied and their apparent affinity binding constants have been determined by use of a competition method with ethidium bromide which was applicable not only for all the free base porphyrins but also for their copper(II) or iron(III) complexes. Whatever their mode of binding may be, their apparent affinity binding constants were relatively high (Kapp between 1.2 x 10(7) and 5 x 10(4) M-1 under our conditions), and a linear decrease of log Kapp with the number of porphyrin charges was observed. Studies of porphyrin-DNA interactions by UV and fluorescence spectroscopy, viscosimetry, and fluorescence energy transfer experiments showed that not only the tetracationic meso-tetrakis[N-methyl-4(or 3)-pyridiniumyl]porphyrins, which both involved four freely rotating meso-aryl groups, but also the corresponding tri- and dicationic porphyrins were able to intercalate into calf thymus DNA. Moreover, the cis dicationic meso-bis(N-methyl-2-pyridiniumyl)diphenylporphyrin, which involved only two freely rotating meso-aryl groups in a cis position, was also able to intercalate. The other meso-(N-methyl-2-pyridiniumyl)n(phenyl)4-nporphyrins, which involved either zero, one, or two trans freely rotating meso-aryl groups, could not intercalate into DNA. These results show that only half of the porphyrin ring is necessary for intercalation to occur.

Genetic investigation of fibromuscular dysplasia identifies risk loci and shared genetics with common cardiovascular diseases

Fibromuscular dysplasia (FMD) is an arteriopathy associated with hypertension, stroke and myocardial infarction, affecting mostly women. We report results from the first genome-wide association meta-analysis of six studies including 1556 FMD cases and 7100 controls. We find an estimate of SNP-based heritability compatible with FMD having a polygenic basis, and report four robustly associated loci (PHACTR1, LRP1, ATP2B1, and LIMA1). Transcriptome-wide association analysis in arteries identifies one additional locus (SLC24A3). We characterize open chromatin in arterial primary cells and find that FMD associated variants are located in arterial-specific regulatory elements. Target genes are broadly involved in mechanisms related to actin cytoskeleton and intracellular calcium homeostasis, central to vascular contraction. We find significant genetic overlap between FMD and more common cardiovascular diseases and traits including blood pressure, migraine, intracranial aneurysm, and coronary artery disease.

Rapid routes of synthesis of chemically reactive and highly radioactively labeled alpha- and beta-oligonucleotide derivatives for in vivo studies

Development of the antisense oligonucleotide strategy for the regulation of gene expression in vivo poses several problems: the stability of oligonucleotides toward intracellular nucleases, labeling of oligonucleotides with high specific radioactivity, improvements of penetration of oligonucleotides into living cells, and enhancement of antisense action by coupling of chemically active groups. In the present paper synthesis of highly radioactively labeled [32P]- and [35S]oligonucleotide derivatives is described starting from both natural (beta) and nuclease-resistant (alpha) anomers of oligonucleotides. Conditions for preparative phosphorylation and thiophosphorylation suitable for oligonucleotides of various lengths, base composition, and anomeric forms were established. The stability of the phosphoramide bond under in vivo experimental conditions was checked. The methods of terminal phosphate chemical activation and terminal thiophosphate alkylation were applied to synthesize oligonucleotides equipped with hydrophobic, intercalating, alkylating, and photoactivatable groups. In the case of porphyrin-oligonucleotide conjugates, a series of new monofunctional porphyrin derivatives bearing a free aliphatic amino group was developed.

Évaluation d’une consultation d’urgences en dermatologie

INTRODUCTION

The aim of our study was to understand the motivations of outpatients who come to dermatological emergencies in a university hospital.

PATIENTS AND METHOD

This 6-week prospective study included outpatients who came to the dermatology emergency unit. This consultation is proposed each morning (from 8 to 9), from Mondays to Fridays. A questionnaire was distributed to outpatients. They answered questions on the functioning of this consultation and their own symptoms. The consulting dermatologist answered questions on the referring physician, the really urgent characteristics of the disease and the diagnosis.

RESULTS

Patients were satisfied by the functioning of the consultation. Indeed, 59 p. 100 of outpatients thought that the timetable was convenient and 70 p. 100 that the delay before getting a consultation was rapid. 75 p. 100 felt they needed treatment rapidly. Nonetheless, 45 p. 100 did not think they had a serious disease. More than half of the outpatients were referred by their general practitioner; the others came spontaneously, or were referred by other departments or general emergencies. The most frequent diagnoses were cutaneous infections (27.6 p. 100), eczema (21 p. 100), then benign tumors, psoriasis, physical dermatoses, viral eruptions...

DISCUSSION

A consultation for dermatological emergencies appears to reply to patients' demands. Nonetheless, most of these outpatients do not present with real dermatological emergencies. Criteria for real emergencies needs to be further defined and understood by citizens.

Nickel-Catalyzed Arylation of Acrolein Diethyl Acetal: A Substitute to the 1,4-Addition of Arylhalides to Acrolein

[reaction: see text] In the presence of catalytic amount of NiBr(2) as catalyst precursor, organic halides are reductively coupled at 70 degrees C with acrolein diethyl acetal to give (Z)- and (E)-enolethers by allylic deplacement of an alkoxy group. Subsequent hydrolysis affords beta-arylated aldehydes.

[Neonatal toxic erythema: 3 atypical cases]

Diagnosis of pustular dermatosis occurring during the first days of life is based on clinical findings. Erythema toxicum neonatorum (ETN) is the more frequent benign self limiting eruption in the newborn.

CASE REPORTS

Three cases of ETN with localized pustules to the genitals and perineal area are described.

COMMENT

When encountering a newborn with a localized pustulosis rash, it is important to separate benign condition as ETN from those that require prompt diagnosis and therapy. Atypical ETN and pustular dermatosis due to bacterial or viral infections or inflammatory diseases (e.g., eosinophilic pustulosis) can be differentiated by cytological and bacterial samples.

[Bi-symptomatic CINCA syndrome with inaugural urticaria and major articular lesions]

BACKGROUND

CINCA syndrome (chronic infantile neurological cutaneous and articular syndrome) observed in young children associates chronic urticaria and rheumatological disorders which may cause deformation of the larger peripheral joints. Neurological signs develop later leading to severe prognosis: chronic meningitis, deafness, mental retardation. We present a bisymptomatic case which was distinctive by the absence of central nervous system involvement after 11 years of course.

CASE REPORT

Since the age of six months a female child experienced chronic urticaria with nearly daily episodes. At two years limping was also observed. At nine years, the child had highly deformed knee joints giving a tumoral radiological aspect. The diagnosis of CINCA was made. At the age of 11 years, the child had normal psychomotor development and neurological and biological tests were normal. The knee deformations stablized and the child suffered little from the urticaria.

DISCUSSION

This case of infantile chronic urticaria inaugurated a CINCA syndrome, a condition described in France and termed NOMID (neonatal onset multisystem inflammatory disease) in the English literature. Our case was similar to those reported in the literature showing characteristic skin, biological and rheumatological disorders. The absence of neurological involvement is exceptional and has been confirmed by regular surveillance to 11 years of age. Bone pathology showed a pseudotumoral aspect which has not been described previously.

Shaving: a simple and effective treatment for moderate congenital hypertrichosis

Congenital hypertrichosis is a rare disorder. It is sometimes associated with facial dysmorphism, and dental and gingival abnormalities. This condition constitutes an esthetic problem and regular shaving with a simple razor can be a simple method of treatment.

Numerous and large Bier's spot associated with pregnancy

We report a patient with anemic macules over cyanotic skin which started in the 8th month of a normal pregnancy. We thought that these lesions were close to Bier's spot description although it has never been described during pregnancy. The relationship with pregnancy is likely because skin lesions regress in post-partum. It probably represents an exaggerated physiological response of small vessels to venous hypertension observed during pregnancy in predisposed women.

[Universal dyschromatosis: a familial case]

INTRODUCTION

Universal dyschromatosis is a generalized leucomelanodermia recognised in Japan in 1933. We report a family with universal dyschromatosis, demonstrating the mode of transmission. The ultrastructural aspects are compatible with a functional melanogenesis anomaly.

CASE REPORT

A 9-year-old girl was hospitalized for recently diagnosed insulin-dependent diabetes mellitus. She was born to non-consanguinous parents and her past medical history was uneventful. Her father was of mixed ethnic origin. The physical examination revealed generalized leukomelanoderma identified since the first year of life. Zones of small achromatic maculae alternated with zones of pigmented maculae of variable size and color. Lesions were diffuse but predominated on the trunk and did not involve the face, the hands or the feet. Neither the child nor her father who also has leukomelanoderma were photosensitive. A skin biopsy from the gluteal region revealed alternating zones of hyper- and hypopigmentation. The ultrastructural analysis showed that the number of melanocytes was not significantly different in the different pigmented zones and the pigment transfer to adjacent keratinocytes was intact. There were three other girls in the kinhood and two, as well as a few other individuals in the family, had a localized form of the disease.

DISCUSSION

Universal dyschromatosis is a rare genodermatosis. The familial cases reported here illustrate the variable clinical presentations of this pigmentary abnormality. The pedigree in this family demonstrated incomplete penetrance of hereditary leukomelanoderma with autosomal dominant inheritance. The localized forms reported to date under different names would actually appear to correspond to incomplete expression of the dermatosis. The skin manifestations in universal dyschromatosis would appear to be similar to those in a few other skin diseases, mainly xeroderma pigmentosum, especially the localized forms; for generalized forms however, there is little room for confusion as photosensitivity is absent and lesions predominate in unexposed zones. The ultrastructure investigations showed different levels of melanocyte activity without abnormal pigment production or transfer. This abnormality has variable expression, explaining the multitude of clinical presentations.