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Biomedical subjects

C Lok

Publications and source records attributed to C Lok.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Acquired cutaneous osteomatosis. A primary monomelic form].

Eight cases of sporadic acquired primary osteoma cutis have been reported in the literature. Age at onset varies from 16 to 55 years with a mean of about 35 years. The sex ratio is 1 and a wide range of localizations have been reported. There is no known treatment. We report a new case of primary osteoma cutis observed in an adult. The monomelic feature of this case has not been reported previously. The patient was 76 years old and had multiple painless, stone-like formations at several sites on the left thigh and leg since the age of 40. Histological examination of skin biopsies showed a perfectly differentiated bone tissue in the dermal layer. There was no similar family history nor abnormal morphotype. Likewise, the absence of laboratory signs of pseudohypoparathyroidism, together with the late and spontaneous onset allowed us to eliminate hereditary Albright's osteodystropy or secondary osteomatosis due to a local pathological process. Despite the late onset, the monomelic character of the osteomas observed and the association of hemicorporeal hypertrophy and linear basocellular naevi reported in the literature would suggest a hamartomatous origin rather than a metaplasic process in this patient.

Adolescent↗
PubMed1993

[Acute febrile neutrophilic dermatitis (Sweet's syndrome) during therapeutic agranulocytosis in acute myeloblastic leukemia].

INTRODUCTION: the association of acute febrile neutrophilic dermatosis (Sweet's syndrome) with malignant haemopathies is well known and characterized by an usual lack of hyperleukocytosis: indeed, moderate neutropenia is often reported. However, cases of Sweet's syndrome in the agranulocytosis stage are exceptional (7 in the literature). CASE-REPORT: We report the case of a woman with acute myeloblastic leukaemia who had presented with Sweet's syndrome in the phase of therapeutic aplasia during induction of treatment, in the absence of white blood cells transfusion or treatment with haematopoietic growth factor (GM CSF, GCSF). COMMENTS: the physiopathology of Sweet's syndrome is unknown. Various mechanisms have been suggested, including immune reaction type III, increased interleukin-1 synthesis, increased chemotaxis of neutrophils, action of haematopoietic growth factors, iatrogenic effect of some drugs (e.g. cotrimoxazole, furosemide or minocycline). Yet none of these mechanisms involving circulating polymorphonuclears or their bone marrow precursors can explain the occurrence of Sweet's syndrome in the phase of agranulocytosis. CONCLUSION: the diagnosis of Sweet's syndrome must be considered in patients with agranulocytosis in order to avoid ineffective antibiotics and to initiate a corticosteroid therapy that will accelerate the cure of this benign dermatosis.

Agranulocytosis↗
PubMed1991

Longterm followup after treatment of polyarteritis nodosa and Churg-Strauss angiitis with comparison of steroids, plasma exchange and cyclophosphamide to steroids and plasma exchange. A prospective randomized trial of 71 patients. The Cooperative Study Group for Polyarteritis Nodosa.

We attempted to define the most effective treatment for polyarteritis nodosa and Churg-Strauss angiitis, with a prospective, randomized, multicenter trial of cyclophosphamide in conjunction with corticosteroids and plasma exchanges, compared to corticosteroids and plasma exchanges. A total of 71 patients who fulfilled clinical, histological and/or arteriographic diagnostic criteria were randomly designated to receive either prednisone and plasma exchanges (group A, n = 39) or cyclophosphamide, prednisone and plasma exchanges (group B, n = 32). The end points of the study were control of the disease (recovery and remission) and death. Upon study entry clinical and laboratory features did not differ in the 2 groups. Treatment was stopped in 19 patients because of ineffectiveness in 10 (9 in Group A) and side effects in 9 (8 in Group B). Initial control of the disease was similar in both groups. At 5 years, 27 patients had completely recovered and 14 patients were in clinical remission. The cyclophosphamide-prednisone-plasma exchange association was beneficial in preventing relapses during longterm followup. Nineteen deaths were reported during the followup period. There was no difference between the 10 year cumulative survival rates of the 2 groups (respectively, 72 and 75%). Thus, the association of cyclophosphamide with corticosteroids and plasma exchanges reduced the incidence of relapses and improved the quality of the clinical response to therapy.

Adolescent↗
PubMed1991

[Leg ulcers in Werner's syndrome. Report of one case].

Werner's syndrome (adult progeria) is a rare autosomal recessive condition characterized mainly by a characteristic habitus (short stature, light body weight) scleroderma like changes of the limbs and premature aging. Chronic leg ulcers appears in about fifty per cent of the patients. These ulcers can be related to the combination of mechanical factors on atrophic subcutaneous tissue and skin of the feet and leg associated with early arteriosclerosis (20%) and diabetes mellitus (60%).

Adult↗
PubMed1991

Acute generalized exanthematous pustulosis. Analysis of 63 cases.

We retrospectively analyzed 63 observations collected in nine French departments of dermatology of an acute pustular dermatosis, recently named in the French literature acute generalized exanthematous pustulosis (AGEP). Even though 11 of these cases occurred in patients with a history of psoriasis, AGEP appeared distinct from pustular psoriasis based on several slight pathologic differences, drug induction in most cases, and a more acute course of fever and pustulosis, with rapid spontaneous healing. We, therefore, suggest that AGEP is a reaction pattern, perhaps favored by a "psoriatic background." The most frequent causes of AGEP seem to be drug reactions, acute infections with enteroviruses, and hypersensitivity to mercury. With 55 (87%) of 63 cases attributed to drugs in this series, AGEP should be added to the list of cutaneous adverse drug reactions. Among drug-induced skin eruptions, AGEP is remarkable by its short time to onset after the administration of the suspected drug (less than 24 hours in half of our cases) and the great predominance (80%) of antibiotics as causative agents. It is suggested that some cases previously reported as "drug-induced pustular psoriasis" were in fact AGEP.

Acute Disease↗
PubMed1989

[Acute generalized exanthematous pustulosis].

The authors report the case of a young patient who developed an eruption resembling an acute generalized pustular dermatitis after amoxicillin therapy for a tonsillitis. The nosological distinctions between this clinical entity and pustular psoriasis are discussed.

Adolescent↗
PubMed1989

[Plasma exchange in dermatomyositis and polymyositis. Retrospective study of 38 cases of plasma exchange].

In order to evaluate the efficacity of plasma exchanges (PE) in dermatomyositis and polymyositis, the case histories of 38 patients, who had undergone plasma exchanges between 1980 and 1986 in 10 French plasmapheresis centers, were studied. Large volume PE were performed in 34 patients after failure of conventional therapy and were part of the initial regimen for the 4 others. The initial activity of the muscle disease was acute in 27 patients and subacute or chronic in 11 cases. Clinical results were evaluated on a functional scale based on changes in muscle force: 24 patients improved (10 appreciably and 14 moderately) and 14 remained unchanged. PE were well tolerated in 23 patients. But side effects occurred in 15 patients, necessitating treatment withdrawal in 4 cases. PE seem to be more effective when the dermatomyositis is acute and evolutive than when it is chronic and insidious. The encouraging results of this exhaustive retrospective study prompt us to set up a prospective randomized trial.

Adolescent↗
PubMed1989

[Plasma exchange in dermatomyositis. A retrospective study of 21 cases].

We have reviewed the results obtained in 21 dermatomyositis patients who were treated with plasma exchanges (PE) in 8 french centres between 1980 and 1986. Patients and methods. Seven of the 21 patients studied were male and 14 were female; 16 were children under 15 years of age. The disease was initially acute in 17 cases, subacute in 3 cases and chronic in 1 case. Plasma exchanges were performed as first-line therapy in 13 patients and after failure of the usual treatments in 18 patients. The decision to use PE therapy was prompted by an increase in muscle weakness in 14 of these 18 patients and by a lack of improvement despite treatment in the remaining 4 patients. PE therapy was started 17 months on average after the beginning of treatment. At the time 10 patients were under systemic corticosteroid therapy (prednisone or prednisolone greater than 1 mg/kg/day in 7 cases); 7 patients were receiving immunosuppressants jointly with corticosteroids (prednisone or prednisolone greater than 1 mg/kg/day in 5 cases); and 1 patient had systemic corticosteroids (3 mg/kg/day), methotrexate and antilymphocyte serum. In 3 patients, 2 of whom had severe muscle weakness. PE's were performed from the start. Our 21 patients underwent a total of 234 plasma exchanges. Each patient had a mean series of 11 +/- 6 PE's spread over 11 +/- 3 weeks. In addition to PE therapy, 12 patients received corticosteroids (greater than 1 mg/kd/day in 7 cases) and 8 had corticosteroids (greater than 1 mg/kd/day in 5 cases) together with immunosuppressants. One patient who was put on TE therapy from the start received no other treatment. It must be noted that in 12 patients the introduction of PE was accompanied by another therapeutic change.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Complications of plasma exchange in the treatment of polyarteritis nodosa and Churg-Strauss angiitis and the contribution of adjuvant immunosuppressive therapy: a randomized trial in 72 patients.

We recorded side effects and other complications of 813 plasma exchanges used in early treatment of polyarteritis nodosa and Churg-Strauss angiitis in a prospective study of 72 patients (22-75 years old). All the patients were also treated with a corticosteroid (1 mg/kg/day), and half were included in a randomized trial of cyclophosphamide (2 mg/kg/day during 1 year). Centrifugation was used in 678 plasma exchange sessions (83.4%) and filtration in 128 (15.7%) (no data were available about the technique used in seven cases). The replacement fluid in 745 sessions was 4% albumin and in 115 was fresh-frozen plasma; eight patients received both (47 sessions). Two hundred and fifty-one complications were reported in 60 patients during 206 (25.3%) of the 813 completed exchanges; 47 sessions (5.8%) were temporarily stopped as a result of complications. The most common problems were technical difficulties (in 90 sessions), moderate or severe hypotension (in 52), and allergy to the replacement fluid (in 51). Hepatitis B antigen appeared in one patient. In four patients, plasma exchange was stopped permanently because of the severe side effects. No patient died during a session. Twelve of the 72 patients died during the study, six in each of the two groups. In the group treated by a combination of corticosteroid and plasma exchange, deaths were related to the deleterious effects of the disease itself and occurred after 12.8 +/- 11.1 months (1-26 months). In the group treated by the same combination plus cyclophosphamide, four of the six deaths were due to severe infections, which were related to leukopenia in three patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Ascorbate peroxidase in bovine retinal pigment epithelium and choroid.

Peroxidase, catalyzing hydrogen peroxide reduction concurrent with ascorbate oxidation, was demonstrated in the extract of retinal pigment epithelium and choroid. The peroxidase in the choroid, RPE, and retina are 236.1, 25.1, and 0.5 units/mg protein respectively. Ammonium sulfate fractionation and high pressure liquid chromatography showed that the peroxidase in the RPE-choroid is associated with a group of heme proteins with absorption maxima at 410 nm, and optimal activity at pH 4.5. The high peroxidase activity in the RPE-choroid explains the observation of dehydroascorbate in these tissues and indicates a possible role of this enzyme in the removal of H2O2.

Ammonium Sulfate↗