Late Effects in Mouse Heart after 60Co γ-irradiation of the Brain: An Ultrastructural Study

Summary

A single dose of 8 or 20 Gy ⁶⁰Co γ-rays was given to C3H male mice at 4 months of age. Degenerative changes in the cardiac muscle due to brain irradiation were observed first at 6 months after irradiation, and became progressively more severe at 12–24 months. The changes seen at the ultrastructural level included myofibrillolysis, the presence of lysosomal-like bodies and interstitial fibrosis. Ultrastructural changes in the control cardiac muscle throughout the experimental period were monitored and only minor aging changes were noted. The coronary arteries of control mice began to show a slight amount of smooth muscle degeneration and fibrosis 1 year into the experiment. At 18 months the lesions became more severe, and at 24 months there was relatively less distinction between the control and the 20 Gy treated group. Degenerative changes in the coronary arteries were noticed at 6 months after irradiation, and became progressively more severe at later times (12–24 months). The major changes included smooth muscle degeneration with fibrosis and the accumulation of debris and extracellular matrix. At 18 months the medial smooth muscle showed severe damage, with accumulations of matrix material and debris. There was additional fibrosis in the adventitial layer. There were few additional changes at 24 months after 20 Gy irradiation. Quantitative analyses indicated that the average fractional volumes of degenerated smooth muscle cells were 13, 27 and 39% in the unirradiated group at 12, 18 and 24 months, respectively, and 13 and 29% in the sham-irradiated group at 12 and 18 months into the experiment, respectively. These percentages were 12, 32 and 49% (P < 0·05) after 8 Gy irradiation, and 19% (P < 0·05), 46% (P < 0·01), and 42% after 20 Gy irradiation, respectively.     

Bacillus cereus septicemia attributed to a matched unrelated bone marrow transplant

BACKGROUND: Hematopoietic cell transplantation (HCT) is performed in more than 25,000 patients annually. Clinically significant bacterial transmission from HCT products is rare. CASE REPORT: A 36‐year‐old male of Asian descent with chronic myelogenous leukemia developed sepsis leading to acute renal failure and disseminated intravascular coagulation during infusion of matched unrelated donor bone marrow. This product later tested positive for Bacillus cereus. DISCUSSION: This HCT product traveled 31 hours at room temperature before arriving at the transplant center. Reducing transport times, transporting at 4°C, and enhancing bacterial surveillance of HCT products may increase the ability to detect bacterial proliferation from transport. CONCLUSION: To prevent a similar case in the future, we will begin Gram staining all HCT products in transit more than 24 hours to alert physicians of the need for prophylactic antibiotic therapy.     

Efficacy and safety of losartan in patients with proteinuria

The renoprotective effect and safety of an angiotensin II receptor blocker, losartan, were studied in 11 diabetic and 14 nondiabetic patients with a daily urinary protein excretion >500 mg. Once-daily losartan was administered to all patients for 16 weeks without diuretics or other antihypertensive agents. A daily dose of 50 mg was given to those patients with a sitting systolic blood pressure of between 130 and 170 mm Hg; 25 mg was given to patients with a systolic blood pressure of between 110 and 130 mm Hg. Sixteen patients (6 diabetic and 10 nondiabetic patients) had a more than 25% decrease of their daily urinary protein excretion (response rate 64%). The mean decrease in these 16 patients was 57 +/- 17% (p < 0.05). Two patients (1 diabetic and 1 nondiabetic) had more than a 25% increase of their urinary protein excretion. The trough sitting systolic blood pressure of all patients (n = 25) decreased from 142 +/- 17 to 125 +/- 13 mm Hg (p < 0.05) and the trough sitting diastolic blood pressure from 87 +/- 11 to 78 +/- 11 mm Hg (p < 0.05). Serum uric acid was measured in 16 patients; a decrease from 7.3 +/- 1.6 to 6.6 +/- 1.4 mg/dl (a 9.6% decrease, p < 0.05) was found after 16 weeks. Our study showed that in both diabetic and nondiabetic proteinuric patients once-daily losartan, given as monotherapy at doses of 25 or 50 mg, was effective in reducing blood pressure, serum uric acid levels, and daily urinary protein excretions.     

Gamma knife surgery for trigeminal neuralgia

OBJECT: Stereotactic radiosurgery is an increasingly used and the least invasive surgical option for patients with trigeminal neuralgia. In this study, the authors investigate the clinical outcomes in patients treated with this procedure. METHODS: Independently acquired data from 220 patients with idiopathic trigeminal neuralgia who underwent gamma knife radiosurgery were reviewed. The median age was 70 years (range 26-92 years). Most patients had typical features of trigeminal neuralgia, although 16 (7.3%) described additional atypical features. One hundred thirty-five patients (61.4%) had previously undergone surgery and 80 (36.4%) had some degree of sensory disturbance related to the earlier surgery. Patients were followed for a maximum of 6.5 years (median 2 years). Complete or partial relief was achieved in 85.6% of patients at 1 year. Complete pain relief was achieved in 64.9% of patients at 6 months, 70.3% at 1 year, and 75.4% at 33 months. Patients with an atypical pain component had a lower rate of pain relief (p = 0.025). Because of recurrences, only 55.8% of patients had complete or partial pain relief at 5 years. The absence of preoperative sensory disturbance (p = 0.02) or previous surgery (p = 0.01) correlated with an increased proportion of patients who experienced complete or partial pain relief over time. Thirty patients (13.6%) reported pain recurrence 2 to 58 months after initial relief (median 15.4 months). Only 17 patients (10.2% at 2 years) developed new or increased subjective facial paresthesia or numbness, including one who developed deaf-ferentation pain. CONCLUSIONS. Radiosurgery for idiopathic trigeminal neuralgia was safe and effective, and it provided benefit to a patient population with a high frequency of prior surgical intervention.     

Effects of smoking on pulmonary uptake of technetium-99m methoxyisobutylisonitrile during myocardial perfusion imaging

Background  To determine the influence of smoking on ^99mTc-labeled methoxyisobutylisonitrile (^99mTc-MIBI) lung uptake during myocardial perfusion imaging, we examined 60 subjects with normal myocardial perfusion scans, normal coronary angiograms, and no evidence of left ventricular hypertrophy. Methods and Results  The subjects were divided into 2 groups: Group 1 subjects had smoking histories of at least 10 pack-years and Group 2 subjects were nonsmokers. ^99mTc-MIBI lung to heart ratios (L/H ratios) from anterior planar images were obtained for all subjects during exercise and resting states. ^99mTc-MIBI L/H ratios in smokers were significantly higher than in nonsmokers in both exercise and resting states. However, no significant difference in L/H ratios was found between exercise and resting states in smokers and nonsmokers. In addition, no significant correlation was found between smoking pack-years and either rest or exercise L/H ratios. Conclusions   ^99mTc-MIBI L/H ratios in smokers are higher than in nonsmokers. This must be considered when ^99mTc-MIBI L/H ratios are used clinically.     

Percutaneous pulsed radiofrequency in the treatment of cervical and lumbar radicular pain

BACKGROUND: Previous reports of the efficacy of percutaneous pulsed radiofrequency have been confounded by fewer case numbers, poor patient selection, and limited data on cervical or lumbar radicular pain. We used percutaneous pulsed radiofrequency for cervical and lumbar radicular pain, and the study has more than 100 cases for the analysis of the efficacy of percutaneous pulsed radiofrequency. METHODS: We collected 154 cases of patients with lumbar or cervical radicular pain due to a herniated intervertebral disk or previous failed surgery. They underwent pulsed radiofrequency therapy in 2 to 4 spinal levels unilaterally. Follow-up period was from 1 week to 1 year postoperatively. RESULTS: Twenty-six (53.06%) of 49 patients and 59 (50.86%) of 116 patients after cervical and lumbar pulsed radiofrequency stimulation, respectively, had an initial improvement of 50% or more in the first week of follow-up. Twenty-seven (55.10%) of 49 patients and 52 (44.83%) of 116 patients after cervical and lumbar pulsed radiofrequency stimulation, respectively, had pain relief of 50% or more at the follow-up period of 3 months. In the analysis of patients with pain relief of 50% or more for at least 1 month, the most effective period was during postoperation 1 month later. No complication was found among these patients. CONCLUSIONS: The results of this retrospective analysis showed that the application of pulsed radiofrequency is a safe and useful intervention for cervical and lumbar radicular pain. The satisfactory pain relief obtained by most of our patients justifies the start of this study for at least 6 months. Although pulsed radiofrequency appears to provide intermediate-term relief of pain, further studies with long-term follow-up are necessary.