Anastomotic aneurysms

Although the incidence of anastomotic false aneurysms decreased precipitously with the cessation of usage of silk sutures for vascular anastomoses, the prevalence of these aneurysms has undoubtedly increased in keeping with an ever-increasing volume of peripheral vascular operations. Most aneurysms occur at femoral anastomoses and are easily diagnosed, since most patients present with a groin mass.Anastomotic aneurysms cannot be considered innocuous. Some may rupture and others have been associated with limb ischemia due to acute thrombosis or embolism. Thus, surgical correction is indicated for most anastomotic aneurysms. Patients at high risk with small aneurysms in accessible locations may, however, be followed if they are asymptomatic and there is no evidence of enlargement of the aneurysm [5].     

Management of hematologic and infectious complications of intensive induction therapy for small cell carcinoma of the lung

In an effort to improve response rate and survival in small cell carcinoma of the lung, considerable attention has been focused on induction therapy with intensive chemotherapeutic regimens. The morbidity and mortality of such therapeutic programs have been of considerable concern. The hematologic and infectious complications of highly intensive induction chemotherapy in 72 patients with small cell lung cancer treated at the Johns Hopkins Oncology Center were reviewed, and guidelines for the management of aplasia in this patient population are suggested. Bone marrow aplasia was severe, with 90 percent of 140 cycles of therapy associated with the development of fever. However, during only 20 percent of febrile episodes could a specific site of infection or pathogen be identified. Prophylactic platelet transfusions were administered during 42 percent of courses because of severe thrombocytopenia (platelet count below 20,000/mm3). Only a single significant bleeding episode developed during therapy. The occurrence of bacteremia (9.3 percent of cycles) was strongly associated with the development of severe thrombocytopenia. There were no deaths during aplasia. It is concluded that intensive combination chemotherapy can be safely administered to this elderly patient population with acceptable morbidity provided there is strict adherence to the unique principles of antibiotic usage and platelet support during bone marrow aplasia.     

Prevalence and prognosis of exercise-induced nonsustained ventricular tachycardia in apparently healthy volunteers

Although exercise-induced ventricular tachycardia (VT), whether sustained or nonsustained, is usually associated with significant organic heart disease, its prevalence, associated characteristics and prognostic significance in an asymptomatic, unreferred community-dwelling population are unknown. Therefore, the prevalence of VT associated with maximal treadmill exercise was assessed in 597 male and 325 female volunteers, aged 21 to 96 years (mean +/- standard deviation 54 +/- 16), from the Baltimore Longitudinal Study on Aging who were without apparent heart disease. Ten subjects, 7 men and 3 women, with exercise-induced VT were identified, representing 1.1% of those tested; only 1 was younger than 65 years. All episodes of VT were asymptomatic and nonsustained. In 9 of 10 subjects, VT developed at or near peak exercise. The longest run of VT was 6 beats; multiple runs of VT were present in 4 subjects. Two subjects had exercise-induced ST-segment depression, but subsequent exercise thallium scintigraphic results were negative in each. Compared with a group of age- and sex-matched control subjects, those with asymptomatic, nonsustained VT displayed no difference in exercise duration, maximal heart rate, or the prevalence of coronary risk factors or exercise-induced ischemia as measured by electrocardiography and thallium scintigraphy. Over a mean follow-up period of 2 years, no subject has developed symptoms of heart disease or experienced syncope or sudden death. Thus, exercise-induced VT in apparently healthy subjects occurs almost exclusively in the elderly, is limited to short, asymptomatic runs of 3 to 6 beats usually near peak exercise, and does not portend increased cardiovascular morbidity or mortality rates over a 2-year period of observation.     

The metabolism of lysergic acid di[14C]ethylamide ([14C]LSD) in the isolated perfused rat liver

Isolated female rat livers were perfused with a medium containing [¹⁴C]LSD (1 mg and 0.13 μCi/g liver) and (+)-tartaric acid (15 mg). After 4.5 hr, the bile collected contained some 44% of the added radioactivity, the perfusate, 20% and the liver itself, 20%.The radioactive compounds in the bile were identified as 14-hydroxy-LSD glucuronide (21% of the added ¹⁴C), 13-hydroxy-LSD glucuronide (8%), 2-oxo-LSD (7%) and unchanged LSD (1%). Those in the pooled perfusate and homogenised liver were unchanged LSD (18%), 2-oxo-LSD (5%), a naphthostyril derivative of LSD (4%; probably derived from 2-oxo-LSD), nor-LSD (4%), hydroxy-LSD glucuronides (3%) and de-ethyl-LSD (2%).     

Relationship between in vivo mitomycin c exposure,sister chromatid exchange induction and in vitro mitogenic proliferation. II. Effect of aging on spleen cell mitogenesis and sister chromatid exchange induction

The stress of increased magnesium concentration and of antibiotic action was used to test for changes in the capacity of ribosomes to maintain the fidelity of translation in protein synthesis during aging. Elongation fidelity of ribosomes isolated from livers of young adult (6–10 months, n = 9) and old (23–24 months, n = 11) rats was assessed for poly(U) message through the error co-incorporation of leucine (Leu) with phenylalanine (Phe), using controlled rate measurements.No statistically significant difference in the error response of ribosomes from young and old animals was detected on manipulating magnesium. The maximum Phe and Leu rates occurred at ～8 and ～11 mM Mg²⁺, respectively, the relative error frequency (Leu/Phe ratio) at the Leu maximum was ～2%.The aminoglycoside paromomycin (PM) elicited a considerably higher degree of error incorporation: 12–14% Leu/Phe in the range of the Leu rate maximum, 40–60 μM paromomycin, at 9 mM Mg²⁺. A statistically significant increase was detected in the error frequency for ribosomes from old as compared with young animals (at p < 0.02) between 20 and 60 μM paromomycin, the largest increase (～9%) occurring at the Leu rate maximum. Also, the ribosomes from the old animals, in terms of the error frequency, were found to be significantly more sensitive to paromomycin concentration (at p < 0.02) up to the Leu maximum.These results indicate that liver ribosomes of old rats may have a slightly decreased capacity to maintain fidelity, which can be expressed under particular conditions.     

Secondary aortoenteric fistula: A 20 year experience

During a 20 year period at the Johns Hopkins Medical Institutions, 17 patients were operated on for secondary aortoenteric fistula. The interval from initial operation to the onset of symptoms varied greatly and averaged 2.8 years. Symptoms included not only gastrointestinal bleeding but also sepsis and abdominal or back pain. Associated advanced cardiovascular disease was common. Helpful preoperative diagnostic studies included esophagogastroduodenoscopy, aortography, barium contrast gastrointestinal series and groin sinography. However, a high index of suspicion was the most important element of diagnosis. Overall operative mortality was high (47 percent). All six patients with a graft left in the retroperitoneum had an unsatisfactory result (four instances of recurrent aortoenteric fistula). Successful repair was accomplished only in those patients undergoing graft excision and axillofemoral bypass.     

Contingency management approaches to drug self-administration and drug abuse: Efficacy and limitations

This paper discusses substance abuse disorders as being cases of reinforced operant behavior and argues that drug self-administration behavior can be productively studied and influenced within the framework of contingency management approaches to operant behavior. Three aspects of the approach are discussed: (1) reinforcement by drugs; (2) schedule of drug availability; and (3) scheduled consequences of drug self-administration. Each is discussed with respect to the generality of relationships between species, between drug classes, and between basic laboratory and applied clinical or social situations with the intent of documenting the efficacy of the contingency management approach. Subsequent sections discuss limitations of the approach and suggest directions for future research.