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Biomedical subjects

G A Luzzi

Publications and source records attributed to G A Luzzi.

At least 37 records · Page 2Linked to original sources
PubMed1993

Clinical features and management of recurrent balanitis; association with atopy and genital washing.

OBJECTIVE: To evaluate clinical features and diagnostic investigations in patients with recurrent or unresponsive balanitis in order to institute rational management. DESIGN: Forty-three patients presenting to a genitourinary medicine clinic with recurrent or persistent balanitis were studied. All patients were asked whether they had a history of atopic illness and about their practice of genital washing. All patients were investigated by taking a swab specimen from the preputial area for bacterial and viral culture and 30 underwent biopsy of the affected skin. Follow-up was between three and six months. SETTING: Outpatient genitourinary medicine clinic, St Mary's Hospital, London, UK. RESULTS: In 31 (72%) of the patients a diagnosis of irritant dermatitis was made. In comparison with the remaining patients, they had a greater lifetime incidence of atopic illness and more frequent daily genital washing with soap. For 28 (90%) of these patients, use of emollient creams and restriction of soap washing alone controlled symptoms satisfactorily. For the remaining 12 patients, a variety of diagnoses were made. Biopsy proved a well tolerated and diagnostic investigation, but the isolation of microbial pathogens from preputial swabs was irrelevant to management. CONCLUSION: A history of atopic illness and of the practice of penile washing are important aspects in the evaluation of patients with recurrent balanitis. Biopsy is an important investigation in the condition when it does not seem to be caused by irritant dermatitis.

Adult↗
PubMed1993

Adverse effects of antimalarials. An update.

Various drugs are widely used in the prophylaxis and treatment of malaria. In the prevention of malaria in travellers, a careful risk-benefit analysis is required to balance the risk of acquiring potentially serious malaria against the risk of harm from the prophylactic agent. Unfortunately, the information needed to perform accurate analyses of this type is not available for most antimalarials. In the prophylaxis of malaria, chloroquine and proguanil have an excellent safety record, being very rarely associated with severe adverse reactions in the recommended dosages. However, in many parts of the world they are no longer effective prophylactic agents. Pyrimethamine-dapsone (Maloprim) is associated with agranulocytosis, especially if the recommended dose is exceeded, and should be reserved as a second-line agent for travellers to high risk areas. Pyrimethamine-sulfadoxine (Fansidar) and amodiaquine are associated with a relatively high incidence of potentially fatal reactions, and are no longer recommended for prophylaxis. Mefloquine, a relative newcomer, may provoke severe neuropsychiatric reactions with a frequency of 1 in 15,000 to 20,000 users at the prophylactic dosage. In the treatment of Plasmodium falciparum malaria, which has a high mortality if untreated, a greater risk of adverse reactions to antimalarial drugs is acceptable. As chloroquine resistance has become widespread, alternative agents including quinine, mefloquine, pyrimethamine-sulfadoxine, tetracyclines, halofantrine and artemisinin (qinghaosu) and its derivatives may be used in treatment regimens. The therapeutic ratios for chloroquine, quinine and mefloquine are narrow and toxicity is frequent when recommended treatment dosages are exceeded; parenteral administration above the recommended dose range is especially associated with the hazards of cardiac and neurological toxicity.

Animals↗
PubMed1991

Surface antigen expression on Plasmodium falciparum-infected erythrocytes is modified in alpha- and beta-thalassemia.

In an attempt to determine the mechanism whereby thalassemia in its milder forms may protect against malaria, we have examined the expression of neoantigen at the surface of Plasmodium falciparum-parasitized thalassemic red cells. Neoantigen expression was estimated by measurement of antibody bound after incubation in serum from adults living in a malaria-endemic area, using a quantitative radiometric antiglobulin assay. We found that P. falciparum-parasitized alpha- and beta-thalassemic red cells bind greater levels of antibody from endemic serum than controls: mean binding ratios (+/- SE), respectively, for alpha- and beta-thalassemia compared with controls were 1.69 +/- 0.12 and 1.23 +/- 0.06 on a cell for cell basis, and 1.97 +/- 0.11 and 1.47 +/- 0.08 after a correction for surface area differences. Binding of antibody increased exponentially during parasite maturation. In addition, we found a small but significant degree of binding of naturally occurring antibody to parasitized red cells, the extent of which was also greater in thalassemia. The apparent protective effect of thalassemia against malaria may be related to enhanced immune recognition and hence clearance of parasitized erythrocytes.

Animals↗
PubMed1991

Protection by alpha-thalassaemia against Plasmodium falciparum malaria: modified surface antigen expression rather than impaired growth or cytoadherence.

We have attempted to determine the cellular mechanism by which alpha-thalassaemia may protect against Plasmodium falciparum malaria. Invasion and development of P. falciparum in the microcytic red cells of two-gene deletion forms of alpha-thalassaemia when measured morphologically or by [3H]hypoxanthine incorporation were normal compared to controls. Normal invasion rates were also observed following schizogony in thalassaemic red cells. Neither the addition of the oxidant menadione, 30% oxygen, nor modified medium, produced differential damage to parasites within thalassaemic cells. Furthermore, there were no significant differences in the binding of P. falciparum-parasitized alpha-thalassaemic and normal cells to C32 melanoma cells in vitro. However, when neoantigen expression on the surface of infected thalassaemic cells was estimated using a quantitative radiometric antiglobulin assay, clear differences were observed. It was found that alpha-thalassaemic cells bound higher levels of antibody from serum obtained from individuals living in a malaria endemic area than control normal red cells. The binding ratio for thalassaemic compared with controls was 1.69 on a cell-for-cell basis, and 1.97 when related to surface area. The binding of antibody from immune serum increased exponentially during parasite maturation. We also found increased binding of naturally occurring antibody present in non-immune serum to parasitized thalassaemic red cells which also increased during parasite maturation. We conclude that the protection afforded by thalassaemia against malaria may not reside in the ability of parasites to enter, grow or cytoadhere to endothelium in such cells, but may be related to immune recognition and subsequent clearance of parasitized red cells.

Animals↗
PubMed1990

Acyclovir and postherpetic neuralgia.

Studies have demonstrated the benefit of acyclovir, given intravenously or orally, on the acute illness in herpes zoster (HZ). Whether or not such treatment influences the subsequent development of postherpetic neuralgia (PHN) has been the subject of recent controversy. Intravenous acyclovir has not been shown to influence PHN significantly in prospective studies. Oral acyclovir in large doses may reduce PHN during the 3 months after acute HZ, but this effect has not been observed consistently in well-designed studies. From 3 months onwards, no trial has demonstrated a significant effect of oral acyclovir in reducing PHN. The way forward is discussed.

Acyclovir↗
PubMed1990

Unrestricted growth of Plasmodium falciparum in microcytic erythrocytes in iron deficiency and thalassaemia.

The mechanism(s) underlying the apparent resistance to malaria in certain inherited red cell disorders and iron deficiency anaemia remain poorly understood. The possibility that microcytic erythrocytes might inhibit parasite development, by physical restriction or reduced supply of nutrients, has been considered for many years, and never formally investigated. We sought to determine whether in vitro growth studies of P. falciparum could provide evidence to suggest that small red cell size contributes to malaria resistance in those red cell disorders in which microcytosis is a characteristic feature. Invasion and development of P. falciparum in iron deficient red cells (mean values for mean cell volume [MCV] 66 fl, mean cell haemoglobin [MCH] 19 pg) and in the red cells of two gene deletion forms of alpha-thalassaemia (mean MCV 71 fl, MCH 22 pg) were normal, assessed both morphologically, and by 3H-hypoxanthine incorporation. Although parasite appearances were normal in all cell types, morphological abnormalities were noted in iron deficient and thalassaemic cells parasitized by mature stages of P. falciparum, notably cellular ballooning and extreme hypochromia of the red cell cytoplasm. Using electron microscopy, the red cell cytoplasm in parasitized thalassaemic cells showed reduced electron density and abnormal reticulation. Normal invasion rates were observed following schizogony in microcytic cells of both types. Our findings indicate that whilst minor morphological abnormalities may be detected in parasitized iron deficiency and thalassaemic erythrocytes, development of P. falciparum in these conditions is not limited by small erythrocyte size.

Anemia, Hypochromic↗
PubMed1987

Rat-bite acquired leptospirosis.

We report a case of leptospirosis in a boy following a rat-bite, an unusual mode of transmission for this infection. The use of antibiotics for fever following a rat-bite is discussed.

Animals↗
PubMed1987

Combined familial C7 and C4B deficiency in an adult with meningococcal disease.

A case of meningococcal septicaemia is reported in an adult with a deficiency of the seventh component of complement combined with a deficiency of the B locus product of C4. A family study demonstrated that the two deficiencies were not linked. This is the first time that the individual alleles of C4 were determined in a patient with a deficiency of one component of the terminal pathway. It is possible that the heterogeneous clinical picture of a terminal pathway deficiency may, in part, be explained by the co-existence of other subtle complement defects.

Adult↗
PubMedDate not supplied

Brucellosis: imported and laboratory-acquired cases, and an overview of treatment trials.

Following the successful eradication of Brucella abortus infection in cattle, human brucellosis in England and Wales has become an uncommon imported disease. Culture of the organism presents a major laboratory hazard, and difficulties in identification may occur using a biochemical test-strip method. An overview of recent treatment trials of brucellosis indicates that regimens combining streptomycin and doxycycline are associated with a higher success rate (judged by the frequency of treatment failure and relapse following therapy) than combinations of rifampicin and doxycycline.

Adolescent↗
PubMedDate not supplied

The association of human papillomavirus infection with balanoposthitis: a description of five cases with proposals for treatment.

The features and clinical course of chronic balanitis in 5 patients are presented. In each case, histological examination of a cutaneous biopsy sample showed pronounced features of human papillomavirus (HPV) infection. In addition, HPV DNA was demonstrated in each biopsy specimen by a polymerase chain reaction and was found to be type 6 by Southern blot hybridization in 4 of the cases. Although the association of histological features of HPV infection with balanitis does not prove that HPV is causal, the failure to find other causes, the prolonged and distressing symptoms, and the ineffectiveness of topical steroids in improving symptoms, all suggest the importance of HPV infection. While effective treatment needs to be sought and developed, the response of one patient to oral isotretinoin suggests that this agent may be appropriate for a larger trial.

Administration, Oral↗