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Biomedical subjects

P Humbert

Publications and source records attributed to P Humbert.

At least 91 records · Page 5Linked to original sources

Phototherapy in the treatment of cutaneous graft-versus-host disease. Our preliminary experience in resistant patients.

Graft-versus-host disease (GVHD)* is a frequent complication of allogeneic bone marrow transplantation. The potentially beneficial effect of phototherapy for treatment of cutaneous manifestations of GVHD led us to investigate retrospectively the effect of this therapy in a larger series of patients. Eleven patients with cutaneous GVHD (acute GVHD in 4 patients, chronic lichenoid GVHD in 6 patients, and chronic sclerodermatous GVHD in 1 patient) resistant to standard immunosuppressive drugs were treated with phototherapy. Skin lesions showed a complete clearing in 75% of patients with acute GVHD, and a response rate of 70% was observed in patients with chronic GVHD. No effect of phototherapy was achieved in 3 patients. Our results suggest that phototherapy is a nonaggressive treatment that may benefit patients with cutaneous GVHD, who already take high doses of immunosuppressive drugs.

Adolescent↗

[Hereditary angioneurotic edema: an underestimated medical emergency. Apropos of 33 cases].

INTRODUCTION: Hereditary angio-oedema is a poorly understood disease. In more than 70 p. 100 of the cases, diagnosis is made 5 to 10 years after the first manifestations despite their typical nature. PATIENTS AND METHODS: We examined retrospectively 33 cases of hereditary angio-neurotic oedema treated at the Besançon University Hospital from 1973 to 1990. RESULTS: Laryngeal oedema was the most dangerous complication causing a critical episode in 22 cases. Ten patients were given danazol. DISCUSSION: This study emphasizes that preventive treatment is essential, based on danazol which should be prescribed at the lowest dose which gives a 50 p. 100 rise in the C2 complement fraction (usually 50 to 200 mg/day). Life-threatening attacks should be treated with purified C1 INH, although there are still problems with drug supply.

Adolescent↗

[Cutaneous and lymphatic cryptococcosis after transient lymphopenia in an immunocompetent patient].

INTRODUCTION: Cryptococcosis is an opportunistic infection, that rarely occurs in immunocompetent patients. CASE REPORT: We report a case of a 82 year-old woman who suffered from a bacterial pneumonia associated with lymphopenia. During the hospitalisation, she developed a cutaneous and ganglionnary cryptococcosis. No other cause of immunosuppression was found. The lymphopenia disappeared with the healing of the pneumonia treated with systemic antibiotics. Treatment with fluconazole was effective in 2 months on the cryptococcosis. COMMENTS: To our knowledge, this is the first case of cryptococcosis after a transitory lymphopenia, occurring in a immunocompetent patient.

Aged↗

[Toxocariasis. A cosmopolitan parasitic zoonosis].

The infection by Toxocara canis transmitted by dogs (30% of them are infected in our countries) and less frequently by cats lead to larva migrans visceral syndrome with neurological manifestations, ophtalmological affection and various cutaneous manifestations observed in 24% of the extra-ocular infections: chronic urticaria often associated with asthmatic manifestations and chronic rhinitis, angio-oedema or local oedema reaching particularly the eyclid, chronic pruritus associated with lesions due to scratching or to nodular prurigo. An hypereosinophilia is an argument in favour of a progressive infection. High total IgE is an hallmark of visceral infections by parasites and total IgE level is well correlated with the presence of intra-tissular larva. The serological diagnosis is based on the determination of specific IgG by ELISA which appears also to be interesting for the patient's follow up. The western blot method seems to be more specific than the other methods and so is useful to confirm a diagnosis. The treatment given as early as possible is based on the use of diethylcarbamazine but also of thiabendazole, albendazole and mebendazole. Prophylaxis of toxocara infection includes the prohibition of dog access to children games areas but also a frequent turn over of the sand in public parks.

Animals↗

Mutation of His-105 in the beta 1 subunit yields a nitric oxide-insensitive form of soluble guanylyl cyclase.

Soluble guanylyl cyclase [GTP pyrophosphate-lyase (cyclizing); EC 4.6.1.2] is a hemoprotein that exists as a heterodimer; the heme moiety has been proposed to bind nitric oxide, resulting in a dramatic activation of the enzyme. Mutation of six conserved His residues reduced but did not abolish nitric oxide stimulation whereas a change of His-105 to Phe in the beta 1 subunit yielded a heterodimer that retained basal cyclase activity but failed to respond to nitric oxide. Heme was not detected as a component of the mutant heterodimer and protophorphyrin IX failed to stimulate enzyme activity. The activity of the His mutant was almost identical to that of the wild-type enzyme in the presence of KCN, suggesting that disruption of heme binding is the principal effect of the mutation. Thus, the mutation provides a means to inhibit the nitric oxide-sensitive guanylyl cyclase signaling pathway.

Amino Acid Sequence↗

Treatment of psoriasis with a new micronized 5-methoxypsoralen tablet and UVA radiation.

Since 1974, phototherapy with psoralen and ultraviolet A (UVA) has been used successfully for the treatment of psoriasis. However, undesirable side effects, including phototoxicity, nausea, stomach pain and headaches, have led investigators to develop new psoralen compounds. 5-Methoxypsoralen (5-MOP) has thus been introduced as an alternative to 8-MOP because of its less pronounced side effects. Since the absorption kinetics and bioactivity of 5-MOP are known to be variable, a new micronized tablet form (5-MOPm) has been developed. In an open randomized study, oral treatments with 5-MOP or 5-MOPm plus UVA radiation were compared in 22 psoriatic patients. Skin type and initial psoriasis area severity index did not differ significantly between treatment groups. Serum concentrations were significantly higher (320 vs 85.82 ng/ml) and occurred earlier (51.8 vs 229.09 min) with 5-MOPm. In addition, a reduction in PASI of more than 90% was achieved sooner (10.63 vs 17.27 treatments) and with a lower cumulative UVA dose (145.89 vs 232.11 J/cm2), in the group treated with 5-MOPm. No side effects were observed with 5-MOPm. Our data indicate that 5-MOPm has a higher bioavailability, clinical efficacy and tolerability than the commonly used 5-MOP.

5-Methoxypsoralen↗

Effects of a new psoralen, 5-geranoxypsoralen, plus UVA radiation on murine ATPase positive Langerhans cells.

5-geranoxypsoralen (5-GOP), commonly called bergamottin, is a highly photoreactive psoralen, which in contrast to most furocoumarins, does not strongly interact with DNA. 5-GOP gives the opportunity to study, in a more selective way, the mechanisms of phototoxic and immunological activities induced by psoralen and UVA radiation. We investigated the effects of repetitive treatments with 5-GOP plus UVA radiation (320-400 nm) on the number of ATPase+ epidermal Langerhans cells and on the induction of photoreactivity. These effects were compared with those of 8-methoxypsoralen (8-MOP) or 5-methoxypsoralen (5-MOP) plus UVA radiation and UVA radiation alone. C3H/HeN mice were treated topically with the psoralen three times/week for 4 consecutive weeks followed each time by 1 J/cm2 of UVA radiation. At the end of the treatment, mice treated with 8-MOP or 5-MOP plus UVA radiation exhibited severe gross phototoxicity and nearly total depletion of ATPase-stained Langerhans cells. Both treatments produced severe morphological alterations of Langerhans cells. No gross but a microscopic phototoxic effect was observed after 5-GOP plus UVA radiation treatment, while the number of ATPase+ Langerhans cells was also greatly reduced. Interestingly the latter treatment induced no morphological alterations of the remaining Langerhans cells in contrast to treatment with 8-MOP or 5-MOP plus UVA radiation. We conclude that phototoxicity and decrease in the number of ATPase-stained epidermal immune cells observed after treatment with 5-GOP plus UVA radiation are not related to the DNA binding activity of the psoralen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphatases↗

Magnesium hydrogen breath test using end expiratory sampling to assess achlorhydria in pernicious anaemia patients.

A modified magnesium hydrogen breath test, using end expiratory breath sampling, is described to investigate achlorhydria. The efficacy of this test in the diagnostic investigation of pernicious anaemia was compared with that of serum pepsinogen I. Twenty one patients with pernicious anaemia--that is, patients with achlorhydria--and 22 with healed duodenal ulcer and normal chlorhydria were studied. Magnesium hydrogen breath test, serum pepsinogen I, serum gastrin, and standard gastric acid secretory tests were performed in all subjects. The mean (SEM) hydrogen peak value was lower in patients with pernicious anaemia than in the duodenal ulcer group (21.7 (1.9) v 71.3 (5.2) ppm; p = 0.00005). The hydrogen peak value had a 95.2% sensitivity and a 100% specificity to detect pentagastrin resistant achlorhydria. Mean serum pepsinogen I concentrations were also significantly lower in patients with pernicious anaemia than in the duodenal ulcer group (10.7 (2.7) v 123.6 (11.8) micrograms/l p = 0.00005). Sensitivity and specificity to detect pernicious anaemia were both 100% for pepsinogen I. It is concluded that this modified magnesium hydrogen breath test is a simple, noninvasive, cost effective, and accurate method to assess achlorhydria and may be useful in the diagnostic investigation of patients with suspected pernicious anaemia.

Achlorhydria↗

A prospective randomized trial comparing somatostatin and sclerotherapy in the treatment of acute variceal bleeding.

Somatostatin and endoscopic sclerotherapy are widely used in the treatment of acute variceal bleeding. Although objective evidence does exist about the advantages of either treatment, data comparing both procedures are scarce. In order to compare the effectiveness and safety of somatostatin and sclerotherapy in the treatment of acute variceal bleeding, 70 consecutive cirrhotic patients suffering from esophageal variceal hemorrhage and meeting the inclusion criteria were randomly assigned to treatment with somatostatin (35 patients) or sclerotherapy (35 patients). No differences in age, sex, alcohol intake, etiology of cirrhosis and severity of liver failure were found between groups. Failure of treatment (defined as persistence of bleeding despite therapy or subsequent rebleeding within the 48-hr trial period) occurred in seven patients (20%) in the somatostatin group and in six (17.1%) in the sclerotherapy group (NS). Early rebleeding occurred in seven of 28 patients (25%) in the somatostatin group and in five of 29 (17.2%) in the sclerotherapy group (NS). Mortality within the first 6 wk was no different between both groups: 10 (28.5%) and eight (22.8%) in the somatostatin and sclerotherapy groups, respectively. Sclerotherapy, but not somatostatin, was associated with major complications in five cases (14.2%) (p = 0.026), two of which resulted in patient's death. These results suggest that somatostatin is safer, and as effective as sclerotherapy, in controlling acute variceal bleeding until an elective treatment can be established.

Acute Disease↗

Serum free 5-methoxypsoralen fraction in health and psoriasis: relationship with human serum albumin concentration.

Human serum albumin is known to be the main carrier of 5-methoxypsoralen (5-MOP) in serum. As hypoalbuminaemia may occur in psoriasis with inflammatory syndrome, variability of the free 5-MOP fraction in serum can be expected. The free 5-MOP fraction was determined by equilibrium dialysis in serum samples obtained from 18 psoriatic patients and 18 control subjects. The median free 5-MOP fraction was not significantly different in the psoriatic group (fu = 4.75%) than in the control group (fu = 5%). However, there was a significantly larger variability of the free fraction in the psoriatic group (2.7 to 8.6%) than in the healthy group (3.2 to 6.8%) (p = 0.002). The binding index of 5-MOP (ratio of bound to free concentrations) was correlated with human serum albumin level (r = 0.784). This work confirms that the 5-MOP fraction in human serum is principally serum albumin dependent, as has been described with in vitro models. Free drug monitoring of 5-MOP is discussed.

5-Methoxypsoralen↗

Effect of pressure on in vitro percutaneous absorption of caffeine.

The effect of increased pressure, which is a mechanical property of massage, was investigated on the percutaneous absorption of an amphiphilic compound (caffeine) in vitro on Franz diffusion cells, using excised human skin. 50 microliters of either a 320 micrograms/ml or a 15 mg/ml acetone solution of caffeine were pipetted onto the surface of each skin sample, which represented caffeine skin deposits of 5 micrograms/cm2 and 240 micrograms/cm2 respectively. During each experiment, a pressure device delivering 0.25 bar over the atmospheric pressure was applied for the first 30 min on half of the cells. At 2, 4, 6, 8, 12 and 24 h the aqueous dermal bathing solution, containing 14 g/l albumin, was removed and chromatographed. With the applied dose of 5 micrograms/cm2 no statistical difference was found between the cumulated absorbed amount under atmospheric pressure and increased pressure. On the other hand, with the applied dose of 240 micrograms/cm2, the permeation of caffeine was 1.8 times higher under increased pressure than the permeation under atmospheric pressure (p < 0.05). This enhancing effect of increased pressure was probably connected to either an improved transappendageal route during the percutaneous absorption process or a higher stratum corneum filling-up.

Adult↗

Treatment of scleroderma with oral 1,25-dihydroxyvitamin D3: evaluation of skin involvement using non-invasive techniques. Results of an open prospective trial.

1,25-dihydroxycholecalciferol (1,25 (OH)2 D3) causes dose-dependent inhibition of fibroblast growth and collagen synthesis and has numerous immunoregulatory activities. We assessed the effects of oral 1,25 (OH)2 D3 in the treatment of patients with systemic sclerosis (SS). Eleven patients with SS entered an open prospective study. Oral 1,25(OH)2 D3 was given at a mean dose of 1.75 micrograms/day. The effects of the treatment were evaluated using clinical examination and physical measurements. After the treatment period (6 months to 3 years), a significant improvement, as compared with baseline values, was observed. No serious side-effects were observed. These results suggest that high-dose 1,25 (OH)2 D3 may be a useful therapeutic agent for scleroderma.

Administration, Oral↗