Validation of the novel transdermal arterial gasotransmitter sensor (TAGS™) system in measuring transdermal hydrogen sulfide in human subjects.

A novel non-invasive system has been developed to measure transdermally emitted hydrogen sulfide (H2S) from the upper and lower limbs of human subjects. The transdermal arterial gasotransmitter sensor (TAGS™) has previously been shown to detect low levels of H2S ranging between 1 and 100 ppb considered relevant for physiological measurements (Shekarriz et al. 2020). This study was designed to compare its measurement precision in detecting transdermal H2S to a commercially available chemiluminescent device, the H2S-selective Ecotech Serinus 55 TRS™. Although TAGS™ does in-situ and real-time sampling, the comparative studies in this paper collected gases emitted from the lower arm of 10 heathy human subjects between the ages of 30 and 60. Three replicate samples of each individual were collected for 30 min in a sealed 10 L Tedlar® bag to allow readings from the same sample by both devices. Readings from the TAGS™ system correlated strongly with the values obtained from the Serinus™ device, both ranging between 0.31 ppb/min and 2.21 ppb/min, with a correlation coefficient of R2 = 0.8691, p < 0.0001. These results indicate that TAGS™ measures transdermal H2S specifically and accurately. Because vascular endothelial cells are a known source of H2S, TAGS™ measurements may provide a non-invasive means of detecting endothelial dysfunction, the underlying cause of peripheral artery disease (PAD) and microvascular disease. TAGS™ has potential clinical applications such as monitoring skin vascular perfusion in individuals with suspected vascular disease or to monitor progression of wound healing during treatment, which is of particular value in diabetic patients with calcified arteries limiting detection options.

A randomized trial of postoperative adjuvant therapy in patients with completely resected stage II or IIIA non-small-cell lung cancer. Eastern Cooperative Oncology Group.

BACKGROUND: We conducted a randomized trial to determine whether combination chemotherapy plus thoracic radiotherapy is superior to thoracic radiotherapy alone in prolonging survival and preventing local recurrence in patients with completely resected stage II or IIIa non-small-cell lung cancer. METHODS: After surgical staging and resection of the tumor (usually by lobectomy or pneumonectomy), the patients were randomly assigned to receive either four 28-day cycles of cisplatin (60 mg per square meter of body-surface area intravenously on day 1) and etoposide (120 mg per square meter intravenously on days 1, 2, and 3) administered concurrently with radiotherapy (a total of 50.4 Gy, given in 28 daily fractions) or radiotherapy alone (a total of 50.4 Gy, given in 28 daily fractions). RESULTS: Of the 488 patients who were enrolled in the study, 242 were assigned to receive radiotherapy alone and 246 were assigned to receive chemotherapy and radiotherapy. The median duration of follow-up was 44 months. Treatment-associated mortality was 1.2 percent in the group given radiotherapy alone and 1.6 percent in the group given chemotherapy and radiotherapy. The median survival was 39 months in the group given radiotherapy and 38 months in the group given chemotherapy and radiotherapy (P= 0.56 by the log-rank test). The relative likelihood of survival among patients assigned to receive chemotherapy and radiotherapy, as compared with those assigned to receive radiotherapy alone, was 0.93 (95 percent confidence interval, 0.74 to 1.18). Intrathoracic disease recurred within the radiation field in 30 of 234 patients (13 percent) in the group given radiotherapy and in 28 of 236 patients (12 percent) in the group given chemotherapy and radiotherapy (P=0.84); data on recurrence were not available for 18 patients. CONCLUSIONS: As compared with radiotherapy alone, adjuvant radiotherapy and chemotherapy with cisplatin and etoposide does not decrease the risk of intrathoracic recurrence or prolong survival in patients with completely resected stage II or IIIa non-small-cell lung cancer.

Phase III comparison of twice-daily split-course irradiation versus once-daily irradiation for patients with limited stage small-cell lung carcinoma.

PURPOSE: Because small-cell lung cancer is a rapidly proliferating tumor, it was hypothesized that it may be more responsive to thoracic irradiation (TI) given twice-daily than once-daily. This hypothesis was tested in a phase III trial. PATIENTS AND METHODS: Patients with limited-stage small-cell lung cancer were entered onto a phase III trial, and all patients initially received three cycles of etoposide (130 mg/m(2) x 3) and cisplatin (30 mg/m(2) x 3). Subsequently, patients who did not have progression to a distant site (other than brain) were randomized to twice-daily thoracic irradiation (TDTI) versus once-daily thoracic irradiation (ODTI) given concomitantly with two additional cycles of etoposide (100 mg/m(2) x 3) and cisplatin (30 mg/m(2) x 3). The irradiation doses were TDTI, 48 Gy in 32 fractions, with a 2.5-week break after the initial 24 Gy, and ODTI, 50.4 Gy in 28 fractions. After thoracic irradiation, the patients received a sixth cycle of etoposide/cisplatin, followed by prophylactic cranial irradiation (30 Gy/15 fractions) if they had a complete response. RESULTS: Of 311 assessable patients enrolled in the trial, 262 underwent randomization to TDTI or ODTI. There were no differences between the two treatments with respect to local-only progression rates, overall progression rates, or overall survival. The patients who received TDTI had greater esophagitis (> or = grade 3) than those who received ODTI (12.3% v 5.3%; P =.05). Although patients received thoracic irradiation encompassing the postchemotherapy volumes, only seven of 90 local failures were out of the portal of irradiation. CONCLUSION: When TI is delayed until the fourth cycle of chemotherapy, TDTI does not result in improvement in local control or survival compared with ODTI.

Phase II trial of topotecan for the treatment of mesothelioma.

The North Central Cancer Treatment Group designed a phase II trial to assess the efficacy and toxicity of topotecan in patients with unresectable malignant pleural mesothelioma. Twenty-two previously untreated patients with unresectable pleural mesothelioma and good performance status (Eastern Cooperative Oncology Group performance status 0, 1, or 2) were enrolled on this trial from October 1993 through July 1994. Nineteen men and three women, median age 66 years (range, 44-78 years), were treated with topotecan 1.5 mg/m2 intravenously over 30 minutes daily for 5 days at 3-week intervals until toxicity, progression of disease, or a patient decided to discontinue treatment. There were seven patients with measurable disease and 15 with evaluable disease; all were assessable for response and toxicity. A total of 113 cycles of treatment were given, for a median of three cycles (range, 1-26 cycles). Myelosuppression was the most frequent toxicity. Eighteen of 21 patients (86%) experienced grade 3 or 4 neutropenia during the initial treatment cycle. The median neutrophil nadir was 0.5 x 10(3)/microl (range, 0.1-1.6 x 10(3)/microl), and the median platelet nadir was 127 x 10(3)/microl (range, 18-460 x 10(3)/microl). Other toxicities more than grade 2 included malaise (two patients), and anorexia, infection, fever, pulmonary, and cardiac in one patient each. There were no objective responses, and 18 patients had stable disease for a median of 74 days. The median survival for all patients was 230 days, with 23% alive at 1 year. Topotecan as administered in this trial is reasonably well tolerated; however, the response rate was insufficient to warrant additional study in pleural mesothelioma.

Modulation of queuine uptake and incorporation into tRNA by protein kinase C and protein phosphatase.

It has been suggested that the rate of queuine uptake into cultured human fibroblasts is controlled by phosphorylation levels within the cell. We show that the uptake of queuine is stimulated by activators of protein kinase C (PKC) and inhibitors of protein phosphatase; while inhibitors of PKC, and down-regulation of PKC by chronic exposure to phorbol esters inhibit the uptake of queuine into cultured human fibroblasts. Activators of cAMP- and cGMP-dependent kinases exert no effect on the uptake of queuine into fibroblast cell cultures. These studies suggest that PKC directly supports the activity of the queuine uptake mechanism, and that protein phosphatase activity in the cell acts to reverse this. Regardless of the modulation of uptake rate, the level of intracellular queuine base saturates in 6 h. However, there is still an effect on the incorporation rate of queuine into tRNA of fibroblast cultures even after 24 h. We now show that the incorporation of queuine into tRNA in cultured human fibroblasts by tRNA-guanine ribosyltransferase (TGRase) is also stimulated by activators of PKC and inhibitors of protein phosphatase; while inhibitors of PKC decrease the activity of this enzyme. These studies suggest that PKC supports both the cellular transport of queuine and the activity of TGRase in cultured human fibroblasts, and that protein phosphatase activity in fibroblasts acts to reverse this phenomenon. A kinase-phosphatase control system, that is common to controlling both intracellular signal transduction and many enzyme systems, appears to be controlling the availability of the queuine substrate and the mechanism for its incorporation into tRNA. Since hypomodification of transfer RNA with queuine is commonly observed in undifferentiated, rapidly growing and neoplastically transformed cells, phosphorylation of the queuine modification system may be a critical regulatory mechanism for the modification of tRNA and subsequent control of cell growth and differentiation.

Recombinant human erythropoietin therapy for anemic cancer patients receiving cisplatin chemotherapy.

PURPOSE: To assess whether the administration of recombinant human erythropoietin (r-HuEPO) would increase the hematocrit, reduce the requirement for transfusion, and improve the quality of life in anemic cancer patients receiving myelosuppressive, cisplatin-based chemotherapy. PATIENTS AND METHODS: One hundred thirty-two anemic cancer patients receiving cyclic, cisplatin-containing, myelosuppressive chemotherapy were evaluated. Patients received either r-HuEPO (150 U/kg) or placebo, subcutaneously, three times a week for 3 months. Responses were assessed by measuring changes in hemoglobin/hematocrit, transfusion requirement, and quality of life. RESULTS: The mean hematocrit increased by 6.0 percentage points in the r-HuEPO group versus 1.3 in the placebo group. A decrease in transfusion requirement did not reach significance over all 3 months, but there was a significant reduction in the percentage of patients transfused in the second and third months (27% r-HuEPO vs. 56% placebo) and a trend toward reduction in the mean total number of units transfused (1.20 units r-HuEPO vs. 2.02 units placebo), suggesting a lag of 1 month before r-HuEPO can affect the transfusion requirement. Pretreatment serum erythropoietin levels were lower in responders than in nonresponders (73.5 IU/L and 86.3 IU/L means, respectively). However, the magnitude of this difference was not helpful in defining which patients were likely to respond. There was a significant improvement in overall quality of life between the two treatment arms in favor of the r-HuEPO-treated group. There were no significant adverse effects associated with r-HuEPO. CONCLUSIONS: r-HuEPO is safe and can cause a significant improvement in the hematocrit and quality of life of anemic cancer patients receiving myelosuppressive, cisplatin-based chemotherapy. After 1 month of r-HuEPO, there is also a reduction in transfusion requirement.

Activation of transfer RNA-guanine ribosyltransferase by protein kinase C.

Transfer RNA-guanine ribosyltransferase (TGRase) irreversibly incorporates queuine into the first position in the anticodon of four tRNA isoacceptors. Rat brain protein kinase C (PKC) was shown to stimulate rat liver TGRase activity. TGRase preparations derived from rat liver have been observed to decrease in activity over time in storage at -20 or -70 degrees C. Contamination of the samples by phosphatases was indicated by a p-nitrophenylphosphate conversion test. The addition of micromolar concentrations of the phosphatase inhibitors sodium pyrophosphate and sodium fluoride into TGRase isolation buffers resulted in a greater return of TGRase activity than without these inhibitors. Inactive TGRase preparations were reactivated to their original activity with the addition of PKC. In assays combining both TGRase and PKC enzymes, inhibitors of protein kinase C (sphingosine, staurosporine, H-7 and calphostin C) all blocked the reactivation of TGRase, whereas activators of protein kinase C (calcium, diacylglycerol and phosphatidyl serine) increased the activity of TGRase. None of the PKC modulators affected TGRase activity directly. Alkaline phosphatase, when added to assays, decreased the activity of TGRase and also blocked the reactivation of TGRase with PKC. Denaturing PAGE and autoradiography was performed on TGRase isolates that had been labelled with 32P by PKC. The resulting strong 60 kDa band (containing the major site for phosphorylation) and weak 34.5 kDa band (containing the TGRase activity) are suggested to associate to make up a 104 kDa heterodimer that comprises the TGRase enzyme. This was corroberated by native and denaturing size-exclusion chromatography. These results suggest that PKC-dependent phosphorylation of TGRase is tied to efficient enzymatic function and therefore control of the queuine modification of tRNA.

Ceftazidime as monotherapy for fever and neutropenia: experience in a community hospital.

Fever and neutropenia is occurring in a wider variety of clinical settings, and the proper antibiotic therapy for its treatment is an area of debate. Our study is a retrospective analysis of the experience of the Oncology Division of the Medical Center of Baton Rouge, which used ceftazidime as monotherapy in the empiric treatment of fever and neutropenia. A total of 53 episodes in 38 patients were studied. Using ceftazidime as monotherapy in our study population was associated with an 8% mortality rate, indicating that monotherapy is a viable option for the treatment of fever and neutropenia.

Atraumatic severe streptococcal axillary cellulitis.

Axillary streptococcal cellulitis is rare but has been known to clinicians for years. Usually associated with trauma, it may, however, occur in previously healthy individuals who for unknown reasons can be slowly responsive to appropriate antibiotics.

Innovative therapies in hematology and oncology.

As one can see, there are a number of new and exciting advances in the prevention, detection, and treatment of various malignancies. We anxiously await the future to see the exact integration of the tremendous advances taking place in the cellular and molecular biopsy of disease and its application to the therapy of patients.

Phase II trial of carboplatin plus cisplatin in recurrent and advanced squamous cell carcinoma of the head and neck.

Cisplatin is one of the most active chemotherapeutic agents for the treatment of squamous carcinoma of the head and neck; however, neurotoxicity and nephrotoxicity are dose-limiting. The analog, carboplatin, is a promising new agent with similar activity but a different spectrum of toxicity. To evaluate if a therapeutic advantage could be achieved with acceptable toxicity, a combination of carboplatin 350 mg/m2 and cisplatin 50 mg/m2 were administered every 28 days to patients with recurrent or metastatic disease who had received no prior chemotherapy. Of 24 patients enrolled in this study, 21 were assessable for response and toxicity. Five partial responses were observed (24%; 95% confidence interval [Cl], 4.9% to 38.6%). No complete response occurred. Two of these patients received definitive radiotherapy and achieved complete responses. The median survival of all patients was 24 weeks. Hematologic toxicity was dose-limiting necessitating a decrease in the starting dose of carboplatin to 300 mg/m2. Nonhematologic toxicity was infrequent and mild. Significant renal impairment occurred in only two patients. Although treatment with the combination of carboplatin and cisplatin is feasible, we found no therapeutic advantage in terms of an increased response or survival.

Delayed life-threatening pneumonitis secondary to procarbazine.

A patient with advanced Hodgkin's disease being treated with MOPP chemotherapy presented with delayed life-threatening pulmonary toxicity secondary to procarbazine. The pulmonary toxicity began 1 week after procarbazine had been discontinued and once recognized was successfully treated with intravenous steroids.

Leukopenia secondary to mycobacterium leprae.

Hansen's disease (HD) is one of the major infectious diseases in the world with an estimated total of 12 million cases. Physicians in North America, however, rarely see HD or its manifestations. Hematological manifestations of HD have been reported but are not well appreciated. We report a patient with leukopenia while under treatment for active HD who demonstrated mycobacterial involvement of the bone marrow.

Percutaneous lumbar discectomy. An alternative to lumbar laminectomy.

Percutaneous lumbar discectomy demonstrates how technology is improving medicine. The procedure allows the patient to have lumbar disc surgery without all the risks involved with open back surgery. It is relatively noninvasive, decreases operating time, and allows use of local anesthesia which reduces chances of infection, postoperative complications, and cost. With proper patient selection and correct surgical technique, percutaneous lumbar discectomy has the potential to be an alternative to laminectomy for uncomplicated herniated disc surgery.

A study of myc-related gene expression in small cell lung cancer by in situ hybridization.

The expression of myc-related genes (c-myc, N-myc, and L-myc) in small cell lung cancer (SCLC) was studied by RNA-RNA tissue in situ hybridization. The tissues investigated included cytospins of ten cell lines derived from patients with SCLC, four corresponding nude mouse xenografts from cell lines, and metastatic tumor tissue obtained by surgical biopsy and at autopsy. The probes were prepared as 35S labeled complementary RNA. The expression of each gene was demonstrated specifically by autoradiography in the cytoplasm of the neoplastic cell samples. The average levels of oncogene expression in each specimen corroborated previous data obtained by Northern blot assays. In addition, heterogeneity in gene expression from cell to cell in each sample was noted. This study represents the first attempt to demonstrate oncogene expression in lung cancer cell lines and tissues in situ, and confirms that the expression of these myc related genes can be seen in the primary tumor. The technique of RNA-RNA tissue in situ hybridization has great potential in answering fundamental questions of tumor cell heterogeneity and progression in SCLC. It should be useful in both prospective and retrospective studies.

Pulmonary toxicity with combined modality therapy for limited stage small-cell lung cancer.

To assess the pulmonary toxicity of radiation therapy combined with chemotherapy v chemotherapy alone, we reviewed the clinical course of 80 patients with limited stage small-cell lung cancer treated in a randomized prospective trial. Life-threatening pulmonary toxicity, defined as bilateral pulmonary infiltrates extending beyond radiation ports with symptoms requiring hospital admission, developed in 11 patients (28%) receiving combined modality therapy and in two (5%) receiving chemotherapy alone. Eight of these 13 patients died from pulmonary complications with no clinical evidence of tumor in five. Pulmonary toxicity initially presented at a median of 63 days (range, 21 to 150 days) after the start of combined modality therapy and at a median of 217 days after chemotherapy alone. Biopsies obtained in 11 patients with severe toxicity revealed only interstitial fibrosis with no evidence of an infectious agent. Review of pretreatment parameters such as age, performance status, and radiation portal area failed to reveal any significant differences between patients with or without pulmonary complications. However, initial pulmonary function tests (PFTs) revealed a significantly lower vital capacity (P = .03) and forced expiratory volume (FEV/1.0 second) (P = .04) in patients with subsequent pulmonary complications. Pulmonary toxicity was significantly more common with combined modality therapy than with chemotherapy alone (P = .017) and worse than expected with radiotherapy alone. Six- or 12-month PFTs in completely responding patients revealed improvement within the chemotherapy alone group and no clear trend within the combined modality group. For the group treated with radiation therapy and chemotherapy, there was significantly less improvement after 6 or 12 months in the forced vital capacity (P less than .005) and FEV/1.0 second (P less than .005) than observed for the group treated with chemotherapy alone. Despite the increased incidence of pulmonary toxicity, overall survival favored the combined modality arm (P = .07). Enhanced local control and disease-free survival appeared to compensate for the initial increased pulmonary morbidity and mortality in the group with combined modality therapy.