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Biomedical subjects

L Molin

Publications and source records attributed to L Molin.

At least 37 records · Page 2Linked to original sources

Retinoids and systemic chemotherapy in cases of advanced mycosis fungoides. A report from the Scandinavian Mycosis Fungoides Group.

In cases of advance mycosis fungoides, the systemic chemotherapy combination of bleomycin, cyclophosphamide and prednisolone was given to 8 cases, and the same 3-drug combination with the addition of oral retinoids given to 12 cases. All cases were in a progressive phase of the disease. Remission was obtained in 5/8 cases treated with the combination and in 7/12 cases treated with the combination plus retinoids. The remissions were complete in half of the cases, but relapse occurred within 3 to 6 months in all but 2 cases. The two treatment patient groups were not fully comparable but the conclusion is that the addition of retinoids to systemic chemotherapy combination regimens is of some advantage. There still exists, however, need of more adequate treatment modalities in advanced mycosis fungoides.

Bleomycin

Oral retinoids in mycosis fungoides and Sézary syndrome: a comparison of isotretinoin and etretinate. A study from the Scandinavian Mycosis Fungoides Group.

Thirty-nine patients with mycosis fungoides in various stages or Sézary syndrome were treated with isotretinoin and 29 with etretinate as single drug therapy. Complete remission within 2 months was obtained with isotretinoin in 8 cases (21%) and partial remission in another 15 cases (38%). Etretinate induced complete remission in 5 cases (21%) and partial remission in 11 (46%). Only 1 case with Sézary syndrome went into partial remission. The first sign of remission occurred in 2 to 4 weeks. During continued treatment remissions could not always be maintained. Isotretinoin and etretinate were considered to be of equal potency in the treatment of mycosis fungoides.

Drug Eruptions

Neutrophil function in psoriasis: effects of retinoids.

The present investigation focused on the oxidative response of polymorphonuclear neutrophil leukocytes in psoriasis, in particular pustular psoriasis and how this response was affected by different retinoid compounds. In the active phase of pustular psoriasis, the neutrophil chemiluminescence response to the chemotactic peptide f-met-leu-phe and to phorbol myristate acetate was enhanced and correlated to the development of pustules, whereas cells from psoriasis vulgaris patients showed normal chemiluminescence response. Retinoids, particularly tretinoin (= retinoic acid) and isotretinoin caused a pronounced inhibition of the chemiluminescence response only in primed neutrophils in vivo and in vitro, whereas etretinate and the metabolite Ro 10-1670 was less inhibitory. Retinoic acid furthermore inhibited the Fc-mediated phagocytosis, but did not affect C3bi-mediated phagocytosis. These data suggest that the antiinflammatory effect of retinoids may operate by affecting neutrophil activation and function.

Acitretin

Comparative in vivo evaluation of a radioimmunoassay and a chromatographic assay for the measurement of digoxin in biological fluids.

The concentrations of digoxin in plasma and urine samples obtained from three healthy male volunteers, who received 1.2 mg of labeled digoxin perorally and intravenously, were simultaneously measured by a commercially available radioimmunoassay (RIA) and by a combined column thin-layer chromatographic assay (CA). The CA method, previously shown to assay digoxin specifically, was also used to monitor the individual digoxin metabolites. The results of this investigation showed that digoxin was significantly metabolized, particularly after peroral administration. The lower level of sensitivity of the RIA in plasma was 0.4 ng/mL. There were highly significant positive linear correlations between the values of the following parameters of digoxin as obtained by the RIA and CA methods: the concentrations in plasma and urine, the AUCs, and the cumulatively excreted amounts in urine. The two assays did not give completely identical results either with plasma or urine; the slopes of the regression lines deviated from unity in a significant number of cases. However, there was no relationship between the magnitude of the slopes of the regression lines and the extent of metabolism. It was concluded that the commercially available RIA evaluated was specific for digoxin and that the presence of digoxin metabolites did not affect the determinations.

Biotransformation

Long-term oral acyclovir treatment prevents recurrent genital herpes.

Thirty-three patients with frequently recurring genital herpes completed a randomized double-blind, crossover trial with oral acyclovir 200 mg 4 times a day and placebo for periods of 12 weeks. Five patients (15%) had full recurrence during acyclovir treatment and 31 (94%) while receiving placebo. The median time to first recurrence was 20 days for placebo and more than 84 days for acyclovir. It was concluded that acyclovir was well tolerated and an effective treatment to suppress the disease in selected cases of severe and frequently recurring genital herpes. However, the relapses seem to occur with the same rate as before, when the suppressive acyclovir treatment is stopped.

Acyclovir

Factors of importance for valid digitalis assays particularly for the determination of digoxin in plasma and urine.

Four commercial radioimmunoassay (RIA) kits for digoxin varied in precision (coefficient of variation, CV within-assays 5-14%) and accuracy (up to 40%). Thus it seems that such commercial RIA-kits can reach at best a CV within-assay of 5% and a similar variation between assays. Without a good control of the performance, the variation can increase 5-6 times. We found that the precision of digoxin RIA as performed at 27 Swedish laboratories using 10 different methods varied from 0.05 to 0.61 nmol/L in between-assay SD for a pool of 2.60 nmol/L. Up to 100% deviations between the highest and lowest reported concentration of a spiked plasma pool may occasionally occur. Such deviations mostly depend on the laboratory, but there are contributions from the kit and effects of the matrix as well. Matrix effects were observed in plasma samples from patients with uremia, acute myocardial infarction and treated with spironolactone to which digoxin was added to a concentration of 2.50 nmol/L. We found 10% underestimation by one method, 10% overestimation by two methods and 5% overestimation by a fourth method, respectively, with the above described samples. For a good judgement of a found plasma concentration value, calculation of a confidence interval is useful. This can be done by computer fitting of the standard curve after duplicate runs of standards and samples in random order. One source of error in RIA appears to be the use of inaccurate standards. We found that standards provided with different RIA-kits for digoxin varied up to 30%. Various physicochemical properties of cardiac glycosides, which could influence the assays were studied. Both digitoxin and digoxin are sparsely soluble in water (5.1 and 36 mumol/L, respectively). Methanol is a much better solvent, which dissolves 6.9 mmol/L of digoxin and 20-24 mmol/L of digitoxin. Chloroform is a good solvent for digitoxin (29-34 mmol/L) but not for digoxin (0.42 mmol/L). Partition of cardenolides between chloroform and water reflected their lipophilic or hydrophilic character. Thus, digitoxin had a high affinity to the organic phase (distribution constant KD = 10(3.65)), while the hydrophilic deslanoside was preferentially found in the aqueous phase (KD = 10(-3.08). Interestingly, the sugar moiety digitoxose in the digoxin molecule turned out to be a substituent that increased lipophilicity. Adsorption of cardiac glycosides occurs to plastics and glass from aqueous solutions. To overcome losses at low concentrations, the solutions must contain plasma, albumin, alcohol or similar solubility-increasing ingredients.(ABSTRACT TRUNCATED AT 400 WORDS)

Chromatography, High Pressure Liquid

Some observations on various dose regimens of thymopentin treatment in rheumatoid arthritis.

Eight patients suffering from active rheumatoid arthritis were treated with thymopentin, 50 mg, administered as fractionated intravenous infusion over 10 min 3 times weekly for 3-20 weeks. Seven patients experienced clear-cut amelioration of symptoms and signs after just 2-4 weeks of treatment, and this improvement lasted for 6-8 weeks after thymopentin had been discontinued. Comparable positive results were observed in 2 patients who later continued thymopentin therapy by subcutaneous administration. Several subcutaneous dose regimens were tried; the optimal response appears to be achieved with 100-150 mg three times weekly and 150-200 mg twice a week, respectively. Because the subcutaneous therapeutic approach is more attractive to the patient-and also more practical for the physician-it should be investigated further.

Adjuvants, Immunologic

Thymopentin treatment of herpes simplex infections. An open, monitored, multicenter study.

Twenty-seven patients suffering from long-standing, severe, recurrent herpes simplex (14 labial and 13 genital) who had not responded adequately to prior therapy were recruited for this open, monitored study. They were treated with thymopentin 50 mg subcutaneously three times weekly for a period of 6 weeks. Clinical controls were performed once a week and then again 6 weeks after cessation of therapy; laboratory investigations were done at time points 0, 3, and 6 weeks. Additionally, information was collected with regard to the clinical course during the following year. Thirteen of 14 patients with labial infection and 10 of the 13 with genital herpes improved markedly (p less than 0.05) as shown by decrease in the relapse rate of at least 50%, shorter relapse episodes, and improvement of symptoms such as pain and itching. Fourteen of these 27 patients experienced no relapse for a period longer than 4 months after cessation of therapy. These favorable results were paralleled by a statistically significant increase in the T cell helper/suppressor ratio. This finding indicates that thymopentin acts as an immunodomulator; it is assumed that the activation of T helper cells induces-presumable via interleukin 2-the proliferation of cytotoxic T lymphocytes and natural killer cells which play a major role in the natural immune defense. No serious side effects of thymopentin were recorded.

Adjuvants, Immunologic

Thymopentin in chronic Trichophyton rubrum infection.

The case histories of 2 patients with chronic Trichophyton rubrum infections are presented. Both subjects had previously been treated systemically with griseofulvin, but had to be dropped from therapy due to adverse reactions. Topical treatment alone yielded unsatisfactory results. Thymopentin, 50 mg, administered subcutaneously three times weekly for a period of 6 weeks, induced rapid improvement within 3 weeks and almost complete remission 3 weeks later, although the fungi were still present on the skin. This beneficial effect lasted for up to 7 months after cessation of thymopentin therapy. Reinstitution of treatment produced the same response pattern. The clinical and immunological implications of these findings are briefly discussed; thymopentin is believed to enhance the suggested impaired cellular immunity in patients with chronic T. rubum infections.

Adjuvants, Immunologic

Histamine release from mast cells during phagocytosis and interaction with activated neutrophils.

Histamine release from rat peritoneal mast cells was evaluated during interaction with IgG, C3b-bi and Concanavalin A-opsonized yeast particles and activated neutrophils. In contrast to others we could show no phagocytic uptake of yeast particles attaching to Fc, or Concanavalin A receptors on the mast cell. Attached yeast particles opsonized with C3b/bi were also poorly ingested (less than 10% of the attached particles.) Neither could we detect any significant histamine release. If, however, neutrophils were added to the mast cell-yeast particle complex, histamine release was induced particularly in the presence of Concanavalin A-yeast. We furthermore showed that phorbol myristate acetate-activated neutrophils and eosinophils initiated mast cell degranulation and histamine release. This release is not dependent on myeloperoxidase, but on other oxidative metabolites, since myeloperoxidase-deficient neutrophils also induce histamine release. These experiments show that mast cells exposed to immune complexes and activated neutrophils or eosinophils may augment the inflammatory response.

Eosinophils

Myeloperoxidase modulates the phagocytic activity of polymorphonuclear neutrophil leukocytes. Studies with cells from a myeloperoxidase-deficient patient.

Patients lacking the primary granulae enzyme, myeloperoxidase (MPO), do not usually show any increased susceptibility to infection or altered inflammatory response, in contrast to several other biochemical defects in polymorphonuclear neutrophils. We have now evaluated the role of MPO on phagocyte function in a patient with complete MPO deficiency suffering from generalized pustular psoriasis. We found that the MPO-deficient neutrophils showed enhanced phagocytosis (greater than 200% of normal) of IgG- and C3b-opsonized yeast particles and prolonged N-formylmethionyl-leucyl-phenylaline-mediated stimulation of superoxide production. When purified human MPO was added to normal neutrophils during cell adhesion, their Fc- and C3b-mediated phagocytosis was reduced without affecting cell viability. 1 microgram/ml of MPO reduced the Fc and C3b phagocytosis to 47 and 65%, respectively, whereas 10 micrograms/ml reduced the activity to 20 and 54%. Both attachment and ingestion were reduced to a similar extent, indicating that MPO affected the receptor function per se. When MPO was added to the hyperactive MPO-deficient cells, phagocytosis was reduced more rapidly. Catalase, azide, and methionine eliminated the inhibitory effect, and catalase and methionine, in fact, enhanced the phagocytic activity of adherent neutrophils. These data indicate that, apart from being a potent antimicrobial system, the oxidizing activity of the MPO-H2O2-halide system may modulate the inflammatory response by impairing certain receptor-mediated recognition mechanisms of phagocytic cells, which otherwise could elicit inflammatory reactions and tissue injury.

Complement C3b

13-cis-retinoic acid effective in mycosis fungoides. A report from the Scandinavian Mycosis Fungoides Group.

Twenty patients with mycosis fungoides and four with Sézary's syndrome were treated with 13-cis-retinoic acid as single therapy in an initial dose of 1 to 2 mg per kg body weight in most cases. Complete remission in mycosis fungoides was obtained in six cases (33%) and partial remission in another ten cases (50%). No convincing response was observed in three cases, and progression of limited nodular lesions occurred in one case. In cases responding to treatment the first sign of remission was observed within two to four weeks. Our short-term experience is that the drug is effective in early as well as advanced stages of mycosis fungoides. Patients with Sézary's syndrome, however, did not respond to the same extent.

Adult

The effect of thymopentin treatment on the relapse rate in frequently relapsing herpes simplex virus infections.

Twenty-four patients suffering from longstanding severe recurrent herpes simplex, who had not responded to prior therapy, were treated with s.c. thymopentin injections 50 mg, three times weekly, over a period of six weeks. They were followed up at weekly intervals over this period and then six weeks later. Moreover, the longest relapse-free period observed in the year after the treatment was recorded in the investigator's documentation. Thirteen of the 14 patients with labial herpes simplex and 10 of the 13 patients with genital herpes simplex improved markedly as shown by a decrease in the relapse rate of at least 50%, shorter episodes of relapse and improvement of symptoms such as pain and itching. Fourteen of these 27 patients experienced no relapse for a period longer than four months after cessation of the therapy. No serious side-effects were observed. Laboratory examinations before, during and after thymopentin did not reveal significant alterations except for an increase in the T-helper/T-suppressor ratio. The effect of thymopentin is assumed to be due to T-helper cell activation resulting in enhanced interleukin-2 production with subsequent proliferation of cytotoxic T lymphocytes and natural killer cells which are capable of producing immune interferon.

Adult

First observations on high-dosed and long-term thymopentin treatment in active rheumatoid arthritis.

In this pilot study carried out in two centres, six male and two female patients with severe active rheumatoid arthritis (RA) (average duration over 10 years) were treated with thymopentin 50 mg in the form of prolonged i.v. injection (over 10 min), 3 times weekly for 3 to 20 weeks. Two of these patients were subsequently treated with different s.c. doses of thymopentin in a crossover fashion for more than two years, including periods without any treatment or treatment with placebo. The overall clinical efficacy was judged by assessing pain patterns and joint status and the functional stage of the patients according to Steinbrocker; in addition, the sedimentation rate was measured before and after the therapy. Seven out of eight patients showed definite improvement in their clinical status as assessed by the Steinbrocker scale. Most of the symptoms, particularly pain, capsular swelling, tenderness and morning stiffness, were remarkably reduced within 3 weeks of thymopentin treatment. Sedimentation rate decreased in five out of eight patients. Prolonged i.v. injections seemed to have somewhat better effects than s.c. administration; in the latter group the highest dose (3 X 100 mg/week or higher) produced the best results. During placebo treatment and during the medication-free intervals both groups of patients got worse. No side-effects occurred during the study.

Adult