Glucose-6-phosphate dehydrogenase deficiency detection using fluorocytometric assay: Evaluation after 1 year of clinical implementation.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a common enzymopathy that affects red blood cells (RBCs) and renders them susceptible to oxidative stress. G6PD deficiency can cause hemolytic anemia, especially after exposure to certain drugs or infections. The diagnosis of G6PD deficiency is usually based on spectrophotometric measurement of enzyme activity, but this method has limitations in heterozygous females and in patients with other hematological disorders. In this study, we evaluated the use of flow cytometry as an alternative method for detecting G6PD deficiency in 514 samples (265 females and 249 males) from a clinical laboratory. We compared the results of flow cytometry with those of spectrophotometry and molecular analysis, and assessed the performance of flow cytometry in different subgroups of patients. We found that flow cytometry was able to identify G6PD deficiency in most cases, with high sensitivity and specificity. Flow cytometry also allowed the quantification of the percentage of G6PD-deficient RBCs, which varied among heterozygous females due to X-chromosome inactivation. Moreover, flow cytometry detected several cases of G6PD deficiency that were missed by spectrophotometry, especially in heterozygous females with normal or subnormal enzyme activity. However, flow cytometry also showed some false negative results, mainly in patients with sickle cell disease. Therefore, flow cytometry is a reliable and efficient tool for screening G6PD deficiency, but some precautions should be taken in interpreting the results in patients with other hematological conditions.

Laboratory evaluation during high-dose vitamin A administration: a randomized study on lung cancer patients after surgical resection.

The laboratory findings in patients receiving high-dose vitamin A as adjuvant treatment for stage I lung cancer are here reported. A group of 283 patients were randomized to either treatment with retinyl palmitate (300,000 IU daily for 12 months) or standard follow-up, and are now evaluable after a median observation period of 28 months. At regular intervals, all the patients underwent a physical examination, chest roentgenogram, blood chemistries, haematological assays, hepatic and renal function tests and determinations of serum triglycerides and cholesterol. Serum transaminase abnormalities were of similar magnitude in cases and controls, while gamma-glutamyltransferase levels were abnormally elevated in 69% of the treated patients compared to 39% of controls (mean values 149 vs 57 IU/l at 24 months, P less than 0.05). Serum triglyceride concentrations over 150 mg/dl were seen in 74% of treated patients compared to 43% of controls at 12 months, the average concentration was 283 mg/dl compared to 179 mg/dl (P less than 0.05). Cholesterol levels showed a modest, non-significant rise with time in both groups, and there was no other laboratory evidence of toxicity attributable to vitamin A. Serum retinol and retinol-binding protein, assessed on a limited sample of patients, were higher in the treatment arm (P less than 0.05) at 12 months. In our experience 300,000 IU/day of retinyl palmitate can be administered as a possible chemopreventive agent with reasonable safety for up to 2 years.

Surgical therapy in lung cancer with single brain metastasis.

From January 1975 to April 1987, 27 patients underwent surgical resection of non oat cell lung cancer and a single brain metastasis. There were 25 men and 2 women ranging in age from 37 to 70 years. In 21 cases the brain metastasis was synchronous while in 6 cases the onset was metachronous. In 17 cases, the site of the brain metastasis was supratentorial and in 10 cases it was located in the posterior fossa. The chest X-ray confirmed the primary lung tumour in 24 cases. In 3 cases, only bronchoscopy and cytology revealed the primary focus of the tumour. The lung cancer was located in the upper lobe in 25 patients. Upper lobectomy was performed in 23 patients, pneumonectomy in 3, and lower lobectomy in 1. There were no operative deaths. The cell type was adenocarcinoma in 19 cases, squamous cell carcinoma in 4 patients and large cell carcinoma in 4. Only the tumour and nodes were used for staging at thoracotomy. The classification was: 12 patients in stage I, 2 in stage II, and 13 in stage III. At conclusion of the study the longest survival was 68 months after thoracotomy. There was no significant difference in the duration of survival in patients over or under 50 years old. Better results were obtained in patients without node metastases at thoracotomy (median survival of 30 months and an overall 5-year survival of 35%), and in patients with supratentorial metastases (median survival of 22 months and an overall 5-year survival of 23.4%). Our experience confirms that combined surgery prolongs survival and improves the quality of life.