Immunohistochemical expression of P53 suppressor genes and retinoblastoma in laryngeal carcinoma

Carcinoma of the larynx is responsible for 1% of all tumors and for 25% of oncologic disease of the head and neck. Tumor suppressor genes control cell proliferation by suppressing specific mechanisms that stimulate the proliferative response. Rb and p53, both nuclear, are the most studied tumor suppressor genes. We evaluated the immunoexpression of these markers in 72 carcinomas of the larynx and correlated it with patients' clinical parameters: age, sex, occupation, tobacco and alcohol use, marital status, etc. Biological and anatomopathological parameters (tumor stage, histological type, degree of local invasion, and lymph node metastases) also were studied. Statistically significant differences were found in mean immunostaining for the Rb gene with respect to histological grade, lymph node enlargement, and smoking. We observed no positive correlation between p53 and the classic clinical-pathological parameters, although important trends were evident, as well as relatively frequent immunostaining (about 40%) of the total neoplastic population.     

Immunohistochemical markers of cell proliferation in laryngeal carcinoma

Although several clinicopathological factors may contribute to the prognosis of laryngeal carcinoma, these factors are still uncertain because the carcinogenesis process and malignant behavior are not well known. Immunohistochemical methods using two important markers, PCNA and Ki67 antigen, were used to assess proliferative activity in malignant laryngeal lesions. We studied the correlation between expression of these markers and clinical factors in 72 patients with carcinoma of the larynx: age, sex, occupation, smoking, alcohol consumption, marital status, etc. We also analyzed other known biological and histopathological prognostic factors (tumor stage, histological grade, lymph node metastases, and local invasion). PCNA and Ki-67 expression differed significantly in relation to histological grade and lymph node involvement. No associations were seen between the expression of PCNA and Ki-67 antigens and other study parameters.     

Abdominal tuberculous abscesses in AIDS patients: percutaneous treatment.

OBJECTIVE: to analyze certain epidemiological and ultrasonographic features, and the response to percutaneous treatment, of abdominal tuberculous abscesses in patients with human acquired immunodeficiency syndrome. METHODS: we reviewed the clinical records and ultrasonographic findings in 7 patients with abdominal tuberculous abscesses who were treated in our service by ultrasonography-guided percutaneous drainage. RESULTS: in 5 patients there was a previous diagnosis of AIDS. The abscesses (two in one patient) were located mainly in the retroperitoneum and appeared mottled at ultrasonography. Seven of the abscesses were drained via catheter, whereas in the remaining case aspiration puncture was used. Mycobacterium tuberculosis was found in the drained material in 6 patients, and 1 case presented superinfection by Enterococcus faecalis. Percutaneous drainage was effective in 6 patients, and in the remaining case it was only palliative. CONCLUSIONS: the incidence of abdominal tuberculous abscesses is increasing in patients with AIDS, and in some patients it is the first symptom. Abscesses are located primarily in the retroperitoneum. They can be dealt with satisfactorily by percutaneous drainage guided by ultrasonography.     

Prolactin responsiveness to TRH in amenorrheic women with and without galactorrhea.

Sixty women were given intravenous injection of 200 microgram TRH to assess its diagnostic potential as a stimulus to PRL release. Following the administration of TRH, there was a prompt increase in serum PRL to 614.6%, to 296%, to 282.1%, and 34% in normal women, amenorrheic patients, non tumoral galactorrheic cases, and patients with pituitary tumors respectively. The TRH response above baseline of PRL levels was statistically significant in all groups, but the women with pituitary tumors which showed a blunted response. The per cent of increment of PRL levels after TRH was similar in amenorrheic women regardless the presence or not of galactorrhea; this increase was significantly greater than in patients with pituitary tumors (p less than 0.01). The per cent of increment above baseline of PRL was significantly greater in menstruating women than in amenorrheic patients (p less than 0.001). In basis of present data: 1) there is a diminished PRL secretion after TRH in amenorrheic women regardless the presence of galactorrhea or hyperprolactinemia; 2) a blunted response to TRH in hyperprolactinemic women may be indicative of a pituitary tumor.     

Ion channels of glucose-responsive and -unresponsive beta-cells.

To assess whether different electrophysiological characteristics could account for the heterogeneous secretion of individual beta-cells in vitro, we used patch-clamp configurations to study currents in plaque-forming (insulin-secreting) and non-plaque-forming rat pancreatic beta-cells that were distinguished in a reverse hemolytic plaque assay (RHPA) after a 30-min stimulation by 16.7 mM glucose. RHPA showed that the population of single beta-cells under study was stimulated (P less than 0.01-0.001) to secrete insulin by 16.7 mM glucose, 100 microM tolbutamide, 20 microM glyburide, or 30 mM KCl but, under these conditions, also comprised beta-cells that did not secrete detectable amounts of insulin. Under current clamp conditions, secreting and nonsecreting beta-cells showed analogous resting membrane potentials (approximately 60 mV) and were similarly depolarized by 30 mm KCl and 100 microM tolbutamide. Under voltage-clamp conditions, total membrane conductance (approximately 6 nS) was also similar in the glucose-responsive and -unresponsive beta-cells, which, when monitored in the whole-cell configuration after RHPA, showed the following currents: a voltage-dependent Na+ current, a voltage-activated Ba2+ current, a voltage-dependent K+ delayed-rectifier current, a voltage-dependent Ca(2+)-activated K+ current, and a voltage-independent and tolbutamide-sensitive K+ current. In the cell-attached configuration and the presence of 2.8 mM glucose, secreting and nonsecreting beta-cells displayed a similar single-channel activity that was abolished when glucose concentration was raised to 16.7 mM. We conclude that beta-cells studied after RHPA have an electrically normal membrane whether they release insulin in response to 16.7 mM glucose or not.     

Syndrome d’hypersensibilité médicamenteuse en pratique interniste : pièges diagnostique et thérapeutique.Huit observationsDrug-induced hypersensitivity syndrome (DIHS): diagnostic and therapeutic traps. Eight case reports.

Purpose.– Drug-induced hypersensitivity syndrome (DIHS) is an acute and severe drug reaction. Manifestations include severe skin lesions, fever, nodal enlargement, blood eosinophilia and multisystemic involvement. The severe systemic manifestations of DIHS are responsible for a 10% mortality rate. The pertinence of corticosteroid therapy is discussed.Methods. – The authors report eight retrospective cases of DIHS obtained from the PMSI (Programme de Médicalisatiopn des Systèmes d'Information) between November 1991 and November 1998.Results.– The series consisted of five male and three female patients (mean age: 52.6 years; range: 23–83 years). The interval between the introduction of the drug and the onset of the reaction varied from two to eight weeks. Due to severe systemic manifestations, three patients were given corticosteroid therapy. Healing of skin and systemic disorders resolved with a mean delay of 4.4 weeks (range: 1 to 56 weeks).Conclusion.– DIHS can be a diagnostic trap, as there are no diagnostic criteria for DIHS. Only the association of multiple arguments such as the time to the occurrence of symptoms, clinical similarity to many infectious illnesses, hypereosinophilia, atypical lymphocytosis, etc. may help guide diagnosis. DIHS can also be a therapeutic trap, as prompt withdrawal of the offending drug is essential to minimize morbidity. Although still controversial in the literature, the pertinence of corticosteroid therapy may be discussed in case of severe systemic effects. Patch testing can be a valuable tool to determine the responsibility of a drug; however it proves to be useful only when positive.     

Regulation of tau phosphorylation in microtubule fractions by apolipoprotein E.

In Alzheimer's disease (AD), a family of proteins collectively named tau are displaced from their normal association with microtubules and are found in in a hyperphosphorylated state deposited into paired helical filaments (PHFs). PHFs are the hallmark cytoskeletal pathology of the disease, and the degree of PHF pathology correlates with the clinical severity of AD. Certain apolipoprotein E (apoE) isoforms have been identified as either risk or protective factors for AD, and one of the proposed mechanisms involves an interaction and potentially modulatory effects on tau hyperphosphorylation by the different apoE isoforms. In these studies, we directly tested the effects of apoE, E2, E3, and E4 on AD-like phosphorylation of tau in brain microtubule fractions. We found that apoE attenuates tau hyperphosphorylation in the fractions, but the pattern was indistinguishable for the different isoforms.