Mo Of Observation Research Articles

Efficacy of digital breast tomosynthesis combined with magnetic resonance imaging in the diagnosis of early breast cancer.

BACKGROUNDThe incidence and mortality rate of breast cancer in China rank 120th and 163rd, worldwide, respectively. The incidence of breast cancer is on the rise; the risk increases with age but is slightly reduced after menopause. Early screening, diagnosis, and timely determination of the best treatment plan can ensure clinical efficacy and prognosis.AIMTo evaluate the clinical value of magnetic resonance imaging (MRI) combined with digital breast tomosynthesis (DBT) in diagnosing early breast cancer and the effect of breast-conserving surgery by arc incision.METHODSThis study was divided into two parts. Firstly, 110 patients with early breast cancer confirmed by pathological examination and 110 with benign breast diseases diagnosed simultaneously in Changzhi People’s Hospital of Shanxi Province and Shanxi Dayi Hospital from May 2019 to September 2020 were included in the breast cancer group and the benign group, respectively. Both groups underwent DBT and MRI examination, and the pathological results were used as the gold standard to evaluate the effectiveness of the combined application of DBT and MRI in the diagnosis of early breast cancer. Secondly, according to the operation method, 110 patients with breast cancer were divided into either a breast-conserving group (69 patients) or a modified radical mastectomy group (41 patients). The surgical effect, cosmetic effect, and quality of life of the two groups were compared.RESULTSAmong the 110 cases of breast cancer, 66 were of invasive ductal carcinoma (60.00%), and 22 were of ductal carcinoma in situ (20.00%). Among the 110 cases of benign breast tumors, 55 were of breast fibromas (50.00%), and 27 were of breast adenosis (24.55%). The sensitivity, specificity, and area under the curve (AUC) of DBT in the differential diagnosis of benign and malignant breast tumors were 73.64%, 84.55%, and 0.791, respectively. The sensitivity, specificity, and AUC of MRI in the differential diagnosis of benign and malignant breast tumors were 84.55%, 85.45%, and 0.850, respectively. The sensitivity, specificity, and AUC of DBT combined with MRI in the differential diagnosis of benign and malignant breast tumors were 97.27%, 93.64%, and 0.955, respectively. The blood loss, operation time and hospitalization time of the breast-conserving group were significantly lower than those of the modified radical treatment group, and the difference was statistically significant (P < 0.05). After 3 mo of observation, the breast cosmetic effect of the breast-conserving group was better than that of the modified radical group, and the difference was statistically significant (P < 0.05). Before surgery, the quality-of-life scores of the breast-conserving and modified radical mastectomy groups did not differ (P > 0.05). Three months after surgery, the quality-of-life scores in both groups were higher than those before surgery (P < 0.05), and the quality-of-life score of the breast-conserving group was higher than that of the modified radical group (P < 0.05). In the observation of tumor recurrence rate two years after the operation, four patients in the breast-conserving group and one in the modified radical treatment group had a postoperative recurrence. There was no significant difference in the recurrence rate between the two groups (χ2 = 0.668, P = 0.414 > 0.05).CONCLUSIONMRI combined with DBT in diagnosing early breast cancer can significantly improve the diagnostic efficacy compared with the two alone. Breast-conserving surgery leads to better cosmetic breast effects and reduces the impact of surgery on postoperative quality of life.

Estimation of quality of life in patients, suffering cardiomyopathy of ischemic genesis, depending on the method of treatment

Objective. To estimate the changes of the patients’ quality of life in those, suffering ischemic cardiomyopathy after surgical revascularization and transplantation of the stem cells, obtained from umbilical blood.&#x0D; Materials and methods. There was analysis conducted on changes in quality of life in 113 patients, suffering cardiomyopathy of ischemic genesis. In accordance to the therapeutic method applied, the patients were divided into four groups: first - 38 (33.6%) patients, in whom coronary shunting was conducted, the second - 35 (31.0%) patients, in whom coronary arteries stenting was done, the third - 20 (17.7%) patients, in whom surgical revascularization was added by transplantation of the umbilical blood stem cells; and the fourth - 20 (17.7%) patients, in whom conservative therapy only was administered.&#x0D; Results. Estimation of efficacy of the stem cells, obtained from umbilical blood, was conducted, in accordance to the points quantity reduction, using the data from The Minnesota Living with Heart Failure Questionnaire (MLHFQ), by 50.0% in 12 mo of observation. This enhancement of therapeutic efficacy in aspect of the quality of life improvement after complex application of the myocardium revascularization and transplantation of the umbilical blood stem cells have constituted 75.0%, comparing with conservative therapy, 53.7% - comparing with coronary shunting and 48.6% -comparing with the coronary arteries stenting. There was proved the essential raising of probability for achievement of this effect, as well as a probable cumulative restoration of the chances - 4.85 [2.44 - 964]. In accordance to the SF-36 questionnaire answers data; trustworthily higher indices for the physical and psychological health components were obtained in patients, in whom myocardial revascularization were added by the umbilical blood stem cells.&#x0D; Conclusion. After transplantation of stem cells, obtained from umbilical blood, as the additive to the myocardial revascularization for treatment of ischemic cardiomyopathy, the signs of cardiac insufficiency have diminished, tolerance for any physical loading partly renewed, including solemn round of industry and a self-servicing, as well as the indices for the physical and psychological health improved.

Оцінка функціонального ниркового резерву після резекції нирки у хворих з нирково-клітинним раком різних вікових груп

Мета. Оцінити функціональний нирковий резерв (ФНР) у хворих на ранніх стадіях нирково-клітинного раку (НКР) різних вікових груп та його зміни в післяопераційному періоді.&#x0D; Матеріали і методи. У дослідженні взяли участь 49 хворих з НКР на стадії Т1N0M0, G1 – G3, гістологічний підтип НКР: світлоклітинний рак. У всіх хворих спостерігали ознаки сечового синдрому. Всім хворим виконали резекцію нирки. У 1-шу групу включили 9 пацієнтів віком 25 – 43 роки, середній вік становив (34 ± 2,3) року; у 2-гу групу - 17 пацієнтів віком 44–59 років, середній вік становив (50 ± 1,3) року; у 3-тю групу - 23 хворих віком 60 – 74 роки, середній вік становив (67 ± 2,1) року. Швидкість клубочкової фільтрації у всіх хворих дорівнювала або перевищувала 90 мл/хв/1,73 м2.&#x0D; Результати. Через 1 міс після проведеного хірургічного лікування середнє значення ФНР у пацієнтів 1-ї групи становило (13,60 ± 1,24)%, 2-ї групи - (8,70 ± 0,21)%. Через 12 міс після проведеного хірургічного лікування середнє значення ФНР у хворих 3-ї групи становило (3,22 ± 1,16)%.&#x0D; Висновки. У пацієнтів з НКР віком від 25 до 43 років ФНР збережений. Резекція нирки у пацієнтів даної вікової групи не призводить до зниження ФНР протягом 12 міс спостереження. У пацієнтів з НКР віком від 44 до 59 років ФНР також збережений. Після резекції нирки у пацієнтів даної вікової групи протягом 12 міс спостереження відбувається зниження ФНР. У пацієнтів з НКР віком від 60 до 75 років ФНР знижений. Після резекції нирки пацієнти даної вікової групи протягом 12 міс спостереження втрачають ФНР.

Eculizumab Therapy for Chronic Antibody-Mediated Injury in Kidney Transplant Recipients: A Pilot Randomized Controlled Trial.

We hypothesized that de novo donor-specific antibody (DSA) causes complement-dependent endothelial cell injury in kidney transplants, as assessed by expression of endothelial cell-associated transcripts (ENDATs), that may be attenuated through complement inhibition. In total, 15 participants (five control, 10 treatment) with DSA and deteriorating renal function were enrolled. The treatment group received 6 mo of eculizumab followed by 6 mo of observation, whereas controls were observed. The primary end point was percentage change in estimated GFR (eGFR) trajectory over the treatment period. The treatment group had an improved eGFR trajectory versus control, based on our predetermined two-sided 0.10 significance level (p = 0.09). Within-subject analysis of treated participants at 6-mo intervals did not show significant change (p = 0.60). Modeling C1q status showed that C1q-positive patients had significantly higher mean eGFR than patients with negative C1q (p = 0.04). Biopsies revealed elevated renal ENDATs in most participants, but ENDATs were not reduced with complement inhibition. Our data suggest that eculizumab treatment may stabilize kidney function in patients with chronic persistent DSA based on our pilot a priori significance threshold. ENDAT expression predicative of acute humoral injury is not reduced with complement inhibition in this chronic setting. Further studies will be necessary to determine which patients may benefit from eculizumab.

Oral Ezatiostat HCl (Telintra), a Glutathione Analog Prodrug GSTP1-1 Inhibitor, for Treatment of Patients with Myeloid Growth Factor-Resistant Idiopathic Chronic Neutropenia (ICN)

AbstractAbstract 4394 Introduction:Idiopathic chronic neutropenia (ICN) is a group of diseases characterized by low circulating neutrophils, recurrent fevers, mucosal inflammation, and systemic infections. The risk of complications is inversely proportional to the absolute neutrophil count (ANC), with the most severe occurring with ANC of < 0.5 × 109/L. Most patients respond to daily s.c. administration of granulocyte colony stimulating factors (G-CSF); however, some patients do not respond. Patients undergoing G-CSF therapy also often have bone and muscle pain, thrombocytopenia and splenomegaly, complicating therapy. Ezatiostat, a glutathione S-transferase (GST) inhibitor that activates Jun kinase, promoting growth and maturation of hematopoietic progenitors, is an investigational agent in development for treatment of ICN. This report describes 4 patients with longstanding ICN who responded to ezatiostat, all of whom prior to treatment had frequent hospitalizations for sepsis, prolonged courses of antibiotics and poor response to myeloid growth factors. Methods:Patients (pts) with severe ICN and inadequate ANC response to G-CSF were enrolled in this phase 2 trial. After initial starting dose of 2000 mg in divided doses twice daily (b.i.d.) dose-equilibration over 4 weeks, pts were treated with ezatiostat daily for 3 weeks followed by 1 week off. Treatment was given until lack of ANC response or unacceptable toxicity. Clinical benefit was determined by ANC response, infection-free periods, antibiotic use and hospitalizations for infections. Results:Four female pts, age range 23–63, with median ANC of 200 (50–400) were enrolled. Patient 1 is 62 y.o. with longstanding history of infections and treatment with G-CSF. Before entering study, she had recurrent ear, labial, left thigh, pulmonary and sinus infections despite growth factor treatment, to which she had severe reactions. Baseline white blood cell (WBC)/ANC ratio was 2.2/0.7. WBC/ANC improved with ezatiostat for 4 mo to 3.62/1.71 and infections resolved. Patient 2, a 63 y.o. with ICN for 26 years, had a median baseline WBC/ANC on G-CSF treatment of 3.1/.180 and a history of multiple hospital admissions for sepsis, non-healing perineal and decubitus ulcers, and recurrent high fevers within 4 days of cessation of parenteral antibiotics, necessitating resumption. Post-ezatiostat treatment median ANC was 3.1 (range 1.6–3.75) with a persistent infection-free period of over 22 mo with no hospitalizations or antibiotic therapy required. Patient 3, a 23 y.o. with ICN since age 10, initially responded to G-CSF but stopped responding despite injections b.i.d., and ANC never rose above 1000. Her last hospitalization was for methicillin-resistant staphylococcus aureus skin infection, upper respiratory infection with cervical adenopathy, and oral ulcers. She had infections every 3 months and baseline WBC/ANC of 1.4/0.13. She had minimal response over 4 mo of observation, with highest values 2.65/0.92 and median ANC of 0.40, but had no further bacterial infection or use of G-CSF. Patient 4, a 39 y.o. with ICN of 10 years’ duration, had severe bone pain with G-CSF and responses were brief (1–2days). Previously, she had hospital admissions and emergency room visits 4–5 times a year and was ill 2–3 times a week with recurrent urinary tract infections, pneumonias (4–5 times per year), oral ulcers, sinus and gastrointestinal infections, furuncles, and infection after dental work. Baseline WBC/ANC was 1.23/0.20. Currently, her WBC/ANC is 1.50/0.26. While ANC did not increase, infection rate decreased and she had no ER visits or admissions for over 5 mo. She responded to a single 300 mcg dose of of G-CSF with an ANC of 1.0 for a week, suggesting re-sensitization to G-CSF. Most common ezatiostat-related adverse events were grade 1 nausea, abnormal urine/stool odor, and dysgeusia. Conclusions:Ezatiostat, a novel GSTP1-1 inhibitor and jun kinase modulator as treatment of patients with ICN and grade 4 neutropenia not responsive to myeloid growth factors, results in a durable ANC response and clinically significant reductions in serious infections. Results suggest a potential role for ezatiostat as an oral therapy alternative or adjunct to G-CSF in the treatment of ICN in patients who are not responsive to G-CSF. Response to this targeted therapy may also give insight into the pathophysiology of ICN and further study is warranted. Disclosures:Lyons:Telik, Inc.: Research Funding. Wilks:Telik, Inc.: Research Funding. Friedman:Telik, Inc.: Research Funding. Young:Telik, Inc.: Employment, Equity Ownership. Brown:Telik, Inc.: Employment, Equity Ownership.

Appropriate intervention strategies for weight gain induced by olanzapine: A randomized controlled study

Weight gain induced by antipsychotics is the second most frequently given reason for noncompliance with pharmacologic therapy; excessive sedative effects rank first, with extrapyramidal side effects ranking third. Frequently, weight gain leads to inconsistent pharmacologic treatment; this exposes patients to the risk of recurrent symptoms. In fact, one of the key contributors to good clinical outcomes in schizophrenic patients is compliance with pharmacologic treatment. The goals of this study were to evaluate weight gain in a group of patients treated with olanzapine, diet modifications, and moderate physical activity and to compare the findings with those from a second group of patients who were given only olanzapine treatment. For 8 wk, investigators followed 2 groups of patients suffering from schizophrenia and hypomania in bipolar disorder, according to the nosographic criteria of The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The first group (A) of 18 patients (9 female, 9 male) affected by manic episodes in bipolar disorder received olanzapine (10-20 mg/d), jogged lightly for 30 min 3 times a week, and complied with a diet that consisted of 500 kcal/d less than usual. The second group (B) of 10 patients (4 female, 6 male) with schizophrenia received only olanzapine (10-20 mg/d). All patients from both groups were weighed at the beginning of the observation period and weekly thereafter for 2 mo. After 2 mo of observation, group A showed a mean weight gain of 1.47 kg, whereas group B exhibited a mean weight gain of 3.5 kg; the difference between the 2 groups was almost 2 kg (P<.005). Group A showed a statistically significant reduction in weight gain compared with group B, clearly demonstrating the effectiveness of moderate physical activity and diet therapy in reducing weight gain in atypical antipsychotic treatment. Therefore, patient weight and body mass index must be monitored during the first weeks of antipsychotic treatment, with the goals of avoiding significant weight gain and treatment interruption.

PPAR-gamma agonist rosiglitazone ameliorates ventricular dysfunction in experimental chronic mitral regurgitation.

Previously we reported that the beneficial effects of beta-adrenergic blockade in chronic mitral regurgitation (MR) were in part due to induction of bradycardia, which obviously affects myocardial energy requirements. From this observation we hypothesized that part of the pathophysiology of MR may involve faulty energy substrate utilization, which in turn might lead to potentially harmful lipid accumulation as observed in other models of heart failure. To explore this hypothesis, we measured triglyceride accumulation in the myocardia of dogs with chronic MR and then attempted to enhance myocardial metabolism by chronic administration of the peroxisome proliferator-activated receptor (PPAR)-gamma agonist rosiglitazone. Cardiac tissues were obtained from three groups of dogs that included control animals, dogs with MR for 3 mo without treatment, and dogs with MR for 6 mo that were treated with rosiglitazone (8 mg/day) for the last 3 mo of observation. Hemodynamics and contractile function (end-systolic stress-strain relationship, as measured by K index) were assessed at baseline, 3 mo of MR, and 6 mo of MR (3 mo of the treatment). Lipid accumulation in MR (as indicated by oil red O staining score and TLC analysis) was marked and showed an inverse correlation with the left ventricular (LV) contractility. LV contractility was significantly restored after PPAR therapy (K index: therapy, 3.01 +/- 0.11*; 3 mo MR, 2.12 +/- 0.34; baseline, 4.01 +/- 0.29; ANOVA, P = 0.038; *P < 0.05 vs. 3 mo of MR). At the same time, therapy resulted in a marked reduction of intramyocyte lipid. We conclude that 1) chronic MR leads to intramyocyte myocardial lipid accumulation and contractile dysfunction, and 2) administration of the PPAR-gamma agonist rosiglitazone ameliorates MR-induced LV dysfunction accompanied by a decline in lipid content.

Parenteral Calcitonin for Metabolic Bone Disease Associated With Primary Biliary Cirrhosis

No satisfactory treatment is available for metabolic bone disease associated with primary biliary cirrhosis. On the basis of the similarities to postmenopausal osteoporosis, the rationale exists for calcitonin to be tested in clinical studies in patients with primary biliary cirrhosis-associated osteoporosis. We evaluated the effect of calcitonin on bone metabolism and mineral density in 25 women with primary biliary cirrhosis and severe osteopenia. After 6 mo of observation, patients received a synthetic calcitonin or a control treatment consisting of less than one hundredth of the recommended dose of porcine calcitonin. The two treatments were administered in sequence to each patient for two 6-mo periods, with a 3-mo washout between them, according to a crossover design. After the observation period, oral calcium supplementation was started. Bone mineral density was measured by dual-photon absorptiometry of the lumbar spine at study entry and at the beginning and the end of each treatment period. During the observation period bone mineral density fell by 3.5% whereas during the following 6 mo it increased in both the patients who received calcitonin (4.3%) and those who received the control treatment (4.9%). Conversely, after the crossover, bone mineral density decreased during both calcitonin (-2.7%) and control treatment (-2.9%). A significant difference was observed between the two periods but not between the two treatments or between the two sequences of treatment administration. In conclusion, our findings indicate that parenterally administered calcitonin for 6 mo is ineffective in halting bone loss in patients with primary biliary cirrhosis-associated metabolic bone disease, whereas calcium supplementation may have a transient beneficial effect.

Distribution of Larvae of Inopus rubriceps (Diptera: Stratiomyidae) Around Sugarcane Plants

Larval populations of Inopus rubriceps (Macquart) in two sugarcane fields in southern Queensland, Australia, consisted of a mixture of small 7.5 mg) larvae during 20 mo of observation. Small larvae predominated during winter and spring. Large larvae were found closest to the soil surface in autumn (during the pupation period). The median depths of occurrence of large larvae during other months and of small larvae throughout the year were positively correlated with soil temperature and independent of soil moisture. Most larvae were within 15 cm of the surface in all months. Larvae were concentrated along the sugarcane rows.

Maternal growth during pregnancy and decreased infant birth weight

We used stature and measurement of knee height to measure continued maternal growth during adolescent pregnancy in a sample of young gravidas (primigravidas and multiparas) and mature pregnant control subjects. Growth during pregnancy has been masked by a tendency of all gravidas to shrink while pregnant (approximately 0.5 cm over 6 mo of observation). Consequently, growth of many adolescent gravidas has not been clinically apparent. There was no effect on maternal growth during a first pregnancy in adolescence but this may be a result of the relatively good prepregnant nutrition status of the young gravidas in developed countries. Maternal growth during pregnancy, however, is associated with significantly decreased (-282 g, p less than 0.05) birth weight for infants when maternal growth continues during a subsequent adolescent pregnancy. This observation is consistent with the hypothesized competition between the metabolic demands of the growing adolescent mother and the nutrient needs of her developing fetus.

Angiotensin converting enzyme inhibition ameliorates glomerular filtration of macromolecules and water and lessens glomerular injury in the rat.

The effect of enalapril on glomerular hemodynamics and permselectivity and on subsequent sclerosis was studied in male MWF/Ztm rats which spontaneously develop proteinuria and glomerular structural damage. Untreated group 1 and enalapril-treated group 2 (50 mg/liter, in the drinking water) underwent micropuncture studies after 2 mo of observation. After the same period of treatment, group 3 (untreated) and group 4 (enalapril treated) were used for determination of whole-kidney function and neutral dextran clearances. Group 5 (untreated) and group 6 (enalapril treated) were followed for an additional 4 mo and used for kidney function and morphological studies. Enalapril significantly lowered systolic blood pressure, which was elevated in untreated groups, and significantly reduced proteinuria (295 +/- 64 vs. 128 +/- 24 mg/24 h by the end of the study). Despite the reduced renal perfusion pressure, whole-kidney glomerular filtration rate was higher in enalapril-treated than in untreated rats (0.96 +/- 0.14 vs. 0.81 +/- 0.10 ml/min, P less than 0.05) as was the single nephron glomerular filtration rate (54 +/- 7.1 vs. 46 +/- 4.0 nl/min, P less than 0.05). The single glomerular afferent plasma flow was comparable in both groups. Enalapril reduced mean glomerular capillary hydraulic pressure from the normal value of 51 +/- 1 mmHg (untreated rats) to a value lower than normal (44 +/- 1 mmHg, P less than 0.001). These hemodynamic changes were associated with a significant reduction in afferent (approximately 23%) and efferent (approximately 26%) arteriolar resistance. The mean ultrafiltration coefficient was two times higher in the enalapril (0.126 +/- 0.027 nl/s per mmHg) than in the untreated group (0.061 +/- 0.023 nl/s per mmHg). The clearance of dextran macromolecules relative to that of inulin was significantly reduced for all molecular sizes studied (26-64 A) in enalapril-treated vs. untreated rats. Theoretical analysis of dextran fractional clearances using a heteroporous model of neutral solute transport across the glomerular capillary wall indicated that enalapril affected glomerular membrane size selective properties, reducing uniformly the radius of hypothetical membrane pores. Enalapril treatment also significantly limited (P less than 0.01) the development of glomerular structural lesions (mean percentage of sclerotic glomeruli was 4.2 +/- 3.5% [treated] vs. 28 +/- 15% [untreated] rats at the end of the study) as well as tubulo-interstitial damage. These results suggest that the protective effect of enalapril on the development of proteinuria and glomerular sclerosis in this model is due to its property of ameliorating size selectivity and hydraulic permeability of the glomerular capillaries.

Ablation of human colon carcinoma in nude mice by 131I-labeled monoclonal anti-carcinoembryonic antigen antibody F(ab')2 fragments.

Pooled F(ab')2 fragments of three MAbs against distinct epitopes of carcinoembryonic antigen (CEA) were used for radioimmunotherapy of nude mice bearing a subcutaneous human colon carcinoma xenograft. 9-10 d after transplantation when tumor nodules were in exponential growth, 36 mice were treated by intravenous injection of different amounts of 131I-labeled MAb F(ab')2. All 14 mice injected with a single dose of 2,200 (n = 10) or 2,800 microCi (n = 4) showed complete tumor remission. 8 of the 10 mice treated with 2,200 microCi survived in good health for 1 yr when they were killed and shown to be tumor free. Four of nine other mice treated with four fractionated doses of 400 microCi showed no tumor relapse for more than 9 mo. In contrast, all 15 mice injected with 1,600-3,000 microCi 131I-control IgG F(ab')2 showed tumor growth retardation of only 1-4 wk, and 15 of 16 mice injected with unlabeled anti-CEA MAb F(ab')2 showed unmodified tumor progression as compared with untreated mice. From tissue radioactivity distributions it was calculated that by an injection of 2,200 microCi 131I-MAb F(ab')2 a mean dose of 8,335 rad was selectively delivered to the tumor, while the tissue-absorbed radiation doses for the normal organs were: peripheral blood, 2,093; stomach, 1,668; kidney, 1,289; lung, 1,185; liver, 617; spleen, 501; small intestine, 427; large intestine, 367; bone, 337; and muscle, 198. These treatments were well tolerated since out of 19 mice with complete tumor remission only 4 required bone marrow transplantation and 17 were in good health for 6-12 mo of observation. The results demonstrate the selective destruction of established human colon carcinoma transplants by intravenous injection of either single or fractionated doses of 131I-MAb F(ab')2.

Dissolved ATP turnover in the Bransfield Strait, Antarctica during a spring bloom

Ambient concentrations and turnover rates of dissolved adenosine triphosphate (D-ATP) were measured at 5 stations in the Bransfield Strait, Antarctica during the 1986-87 Research on Antarctic Coastal Ecosystem Rates (RACER) field program. The study area was pre-selected to include several different coastal and oceanic habitats expected to vary considerably in timing and magnitude of the annual spring phytoplankton bloom. D-ATP concentrations varied both spatially and temporally during the 4 mo of observation. Dunng the initial stages of bloom development, there was a signif~cant positive correlation between the concentration of particulate (P) ATP (i.e. biomass) and D-ATP; however, this relationship deteriorated later in the season. At the height of the spring bloom (January), we observed a D-ATP concentration gradient in excess of an order of magnitude for our coastal to open ocean transect. Dissolved ATP fluxes (uptake rate times ambient concentration; ng I-' d l ) were highly correlated with D-ATP concentrations, indicating that bloom conditions stimulated both production and removal processes. We assessed the potential role of 3 independent processes as a source of D-ATP in Antarctic coastal waters: excret~on/exudation, production during microor macrozooplankton grazing and cell death/autolysis. Results are most consistent w t h a model that includes phytoplankton release durlng active growth and metabolism as a major source of D-ATP in our study area.

Trichinella spiralis in an Agricultural Ecosystem: Transmission under Natural and Experimentally Modified On-Farm Conditions

A hog found infected with Trichinella spiralis at slaughter was traced to its farm of origin, where an epidemiological investigation found the infection prevalent in swine and rats. Garbage-feeding was not responsible for maintaining the high prevalence of infection on this farm, although it may have been responsible historically for the introduction of the infection. Poor husbandry, malnutrition, and intercurrent disease resulted in frequent death and the availability of porcine carcasses for cannibalism. Tissue samples from partly devoured carcasses contained T. spiralis larvae, implicating cannibalism as a major vehicle for the spread of T. spiralis in the herd. Rats also fed on these carcasses, and their rate of infection increased markedly during the first 5 mo of observation. Experimental investigation indicated that rats could also be important in maintaining a high prevalence of infection in swine. For the purpose of our investigation, the farm was depopulated of swine and restocked with parasite-free, sentinel pigs confined in 3 groups exposed to increasing degrees of contact with rats. Pigs exposed to large numbers of rats acquired infections rapidly, whereas pigs with strongly limited rat exposure failed to acquire infection during a 12-mo period. These results indicate that, when rats are available to swine and the prevalence of T. spiralis infection in the former is high, predation (or scavenging) on rats may be as effective as cannibalism in maintaining a high prevalence of porcine T. spiralis infection.

In vivo therapy of a murine B cell tumor (BCL1) using antibody-ricin A chain immunotoxins.

Prolonged remissions were induced in mice bearing advanced BCL1 tumors by the combined approach of nonspecific cytoreductive therapy and administration of a tumor-reactive immunotoxin. Thus, the vast majority of the tumor cells (approximately 95%) were first killed by nonspecific cytoreductive therapy using total lymphoid irradiation (TLI) and splenectomy. The residual tumor cells were then eliminated by intravenous administration of an anti-delta immunotoxin. In three of four experiments, all animals treated in the above fashion appeared tumor free 12-16 wk later. In one experiment, blood cells from the mice in remission were transferred to normal BALB/c recipients, and the latter animals have not developed detectable tumor for the 6 mo of observation. Because 1-10 adoptively transferred BCL1 cells will cause tumor in normal BALB/c mice by 12 wk, the inability to transfer tumor to recipients might indicate that the donor animals were tumor free. In the remainder of the animals treated with the tumor-reactive immunotoxin there was a substantial remission in all animals, but the disease eventually reappeared. In contrast, all mice treated with the control immunotoxin or antibody alone relapsed significantly earlier (3-4 wk after splenectomy).

Long-term effects of captopril in hypertension

Captopril was given for treatment of hypertension alone or in combination with diuretics to 32 patients for 1- to 4-mo periods. The decrement of mean blood pressure after 1 and 2 mo correlated with pretreatment plasma renin activity (PRA) and the response of blood pressure to infusion of an angiotensin II antagonist. These correlations were no longer apparent after 4 mo of treatment. When subjects with a decrement of mean blood pressure that exceeded 13 mm Hg were compared with nonresponders, responders not only had higher control PRA and higher PRA at 1 mo of treatment, but also had decreased plasma aldosterone levels, decreased urinary aldosterone excretion, and increased serum postassium levels that persisted over the 4 mo of observation. The reduction of plasma aldosterone correlated with the fall of mean blood pressure. Urinary kallikrein, catecholamines, electrolytes, and endogenous creatinine clearance did not change in response to treatment. These findings indicate that the antihypertenisve activity of captopril on long-term administration probably depends in part on the blockade of angiotensin II, but other mechanisms cannot be excluded.

Precocious Sexual Development in Hatchery-Reared and Laboratory-Maintained Male Steelhead Trout (Salmo gairdneri)

The incidence of precocious steelhead trout (Salmo gairdneri) was determined in several Idaho hatchery steelhead populations. The range of incidence of precocious males was 0–64% of the sampled populations. This variation appeared to be related to age of the trout, water temperature, and photoperiod. The incidence of precocious males greatly exceeded the incidence (0.1% of the population when encountered) of precocious females. Precocious male steelhead trout are apparently lost from the migrating smolt population and display mating behavior similar to sea-run adult male steelhead. Precocious males maintained in laboratory conditions remained sexually mature for at least 6 mo of observation. This was reflected by mean gonadal weights and mean gonadosomatic indices from precocious male steelhead which differed significantly from nonprecocious juvenile male steelhead maintained under similar conditions. No consistent pattern of growth was observed among laboratory-maintained trout. Key words: steelhead trout, reproduction, precocious sexual maturation, age, photoperiod, temperature

Conditional Probability Program for Diagnosis of Thyroid Function

The frequencies of occurrence of certain clinical findings (signs, symptoms, and laboratory data) were determined in 879 patients who had been classified as hypothyroid, euthyroid, or hyperthyroid on the basis of their responses to therapy during at least 6 mo of observation. A Bayesian conditional probability model was employed to estimate the probability of each of these three conditions for each possible combination of clinical findings. When the study was limited to 268 cases in which the data were considered reasonably complete, the computer program gave the correct classification (ie, successfully predicted the therapeutic result) in 258 (96%). This degree of accuracy approached the level of agreement to be expected between an expert consultant and a well-qualified diagnosing physician.