Rates of formation and thermal stabilities of RNA:DNA and DNA:DNA duplexes at high concentrations of formamide

The thermal stabilities of RNA:DNA hybrids are substantially greater than those of DNA:DNA duplexes in aqueous electrolyte solutions containing high concentrations of formamide. Association rates to form DNA:DNA duplexes and DNA:RNA hybrids have been measured in these solvents. There is a temperature range in which DNA:DNA rates are negligible and RNA:DNA rates close to optimal.

Multipractice analysis of laparoscopic cholecystectomy in 1,983 patients

We analyzed the results of laparoscopic cholecystectomy in 1,983 patients from a variety of practice settings in order to evaluate a large, cross-sectional experience for this new procedure. Twenty general surgeons from 9 clinics in 4 states examined the records and outcome of their laparoscopic cholecystectomy patients through March 1991. In 88 patients (4.5%), the operation was converted to an open procedure, usually because of marked inflammation and unclear anatomy. A total of 644 cases were performed with laser dissection and 1,339 with cautery, and the results of these 2 methods were similar. There were 41 complications. Reoperation for repair was necessary in 18 patients, including 5 with common duct injuries, and, to date, the outcome has been good in each patient. Seventy-six patients (3.8%) have had recognized common duct stones; these were removed preoperatively by endoscopic sphincterotomy (ERS) in 20 patients, during cholecystectomy in 46 patients, and postoperatively by ERS in 4 patients. In six patients, common duct stones became apparent 1 to 4 months after cholecystectomy. We conclude that trained general surgeons can perform laparoscopic cholecystectomy safely with risks comparable to those for conventional open cholecystectomy.

Evidence for high-energy extraterrestrial neutrinos at the IceCube detector

We report on results of an all-sky search for high-energy neutrino events interacting within the IceCube neutrino detector conducted between May 2010 and May 2012. The search follows up on the previous detection of two PeV neutrino events, with improved sensitivity and extended energy coverage down to about 30 TeV. Twenty-six additional events were observed, substantially more than expected from atmospheric backgrounds. Combined, both searches reject a purely atmospheric origin for the 28 events at the 4σ level. These 28 events, which include the highest energy neutrinos ever observed, have flavors, directions, and energies inconsistent with those expected from the atmospheric muon and neutrino backgrounds. These properties are, however, consistent with generic predictions for an additional component of extraterrestrial origin.

Observation of high-energy astrophysical neutrinos in three years of IceCube data

A search for high-energy neutrinos interacting within the IceCube detector between 2010 and 2012 provided the first evidence for a high-energy neutrino flux of extraterrestrial origin. Results from an analysis using the same methods with a third year (2012-2013) of data from the complete IceCube detector are consistent with the previously reported astrophysical flux in the 100 TeV-PeV range at the level of 10(-8)  GeV cm-2 s-1 sr-1 per flavor and reject a purely atmospheric explanation for the combined three-year data at 5.7σ. The data are consistent with expectations for equal fluxes of all three neutrino flavors and with isotropic arrival directions, suggesting either numerous or spatially extended sources. The three-year data set, with a live time of 988 days, contains a total of 37 neutrino candidate events with deposited energies ranging from 30 to 2000 TeV. The 2000-TeV event is the highest-energy neutrino interaction ever observed.

Androgen responses during physical exercise

The serum androgen response to physical exercise was studied in highly trained athletes and in normal male medical students. Serum androgens rose in response to maximal exercise and the rise was independent of serum luteinizing hormone. No response was obtained with submaximal exercise.

Virtual hepatic resection using three-dimensional reconstruction of helical computed tomography angioportograms

OBJECTIVE

To establish the accuracy of virtual hepatic resection using three-dimensional (3D) models constructed from computed tomography angioportography (CTAP) images in determining the liver volume (LV) resected during resectional liver surgery.

SUMMARY BACKGROUND DATA

The ability to measure LV before surgery could be useful in determining the extent and nature of hepatic resection. Accurate assessment of LV and an estimate of liver function may also allow prediction of postoperative liver failure in patients undergoing resection, assist in volume-enhancing embolization procedures, help with the planning of staged hepatic resection for bilobar disease, and aid in selection of living-related liver donors.

METHODS

A retrospective study was conducted involving 27 patients scheduled for liver resection. Using mapping technology, 3D models were constructed from helical CTAP images. From these 3D models, tumor volume, total LV, and functional LV were calculated and were compared with body weight. The 3D liver models were subjected to a virtual hepatectomy along established anatomical planes, and the resected LV was calculated. The resected volume predicted by radiologists (unaware of the actual weight) was compared with the specimen weight measured after actual surgical resection.

RESULTS

A significant correlation was found between body weight and functional LV but not total LV. The computer prediction of resected LV after virtual hepatectomy of 3D models compared well with resected liver weight.

CONCLUSION

Virtual hepatectomy of 3D CTAP reconstructed images provides an accurate prediction of liver mass removed during subsequent hepatic resection. The authors intend to combine this technology with an assessment of liver function to attempt to predict patients at risk for liver failure after hepatic resection.

First observation of PeV-energy neutrinos with IceCube

We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04±0.16 and 1.14±0.17 PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current ν(e,μ,τ) (ν(e,μ,τ)) or charged-current ν(e) (ν(e)) interactions within the IceCube detector. The events were discovered in a search for ultrahigh energy neutrinos using data corresponding to 615.9 days effective live time. The expected number of atmospheric background is 0.082±0.004(stat)(-0.057)(+0.041)(syst). The probability of observing two or more candidate events under the atmospheric background-only hypothesis is 2.9×10(-3) (2.8σ) taking into account the uncertainty on the expected number of background events. These two events could be a first indication of an astrophysical neutrino flux; the moderate significance, however, does not permit a definitive conclusion at this time.

X-linked mental retardation associated with macro-orchidism

Two families are described with an X-linked form of mental retardation in whom the affected males were found to have bilateral enlargement of the testes. No conclusive evidence of any endocrinological disturbance was found.

Clinical significance of immunophenotype in diffuse aggressive non-Hodgkin's lymphoma

We performed a prospective study of the clinical significance of immunophenotype in 110 patients with aggressive non-Hodgkin's lymphoma (NHL) treated by oncologists in the Nebraska Lymphoma Study Group between October 1982 and May 1986. All patients were immunophenotyped from biopsies performed before therapy was administered. The patients were treated with a uniform protocol of radiotherapy for minimal nonbulky, stage I or II disease (seven patients) or a single, six-drug chemotherapy regimen cyclophosphamide, doxorubicin, procarbazine, bleomycin, vincristine, and prednisone (CAP-BOP) in patients with more extensive disease (103 patients). Ninety-one patients (83%) had B-cell lymphoma and 19 patients (17%) had T-cell lymphoma. The histologic diagnosis of diffuse mixed-cell lymphoma was significantly associated with T-cell immunophenotype (45% v 5%; P less than .001), and the diagnosis of diffuse large-cell lymphoma was significantly associated with B-cell immunophenotype (40% v 5%; P = .006). However, no significant difference in frequency of prognostic variables such as age, stage, systemic symptoms, tumor bulk, serum lactic dehydrogenase, or performance status was found between the B-cell and T-cell groups. Patients with B-cell NHL had a slightly higher complete remission rate (74% v 53%; P = NS), similar durability of complete remission (75% v 70% at 3 years; P = NS), and a slightly but not significantly better overall survival (50% v 41% at 3 years; P = NS). The slight advantage in response rate and survival for B-cell patients was related to a very poor outcome for patients with stage IV T-cell NHL. For patients with stage I to III disease, neither the complete remission rate (B-cell, 82% v T-cell, 91%; P = NS) nor overall survival (3-year survival for B cell, 58% v T cell, 73%; P = NS) were significantly different. However, with stage IV disease B-cell patients fared far better than those with T-cell NHL for both complete remission rate (67% v 0%; P = .002) and overall survival (3-year survival, 44% v 0%; P = .002). Immunophenotyping intermediate- and high-grade NHL allowed identification of a subgroup of patients who had a very poor prognosis with this treatment approach and for whom alternate therapy might be considered.

Treatment of severe diabetes mellitus by insulin infusion

A new and simple form of insulin therapy for diabetic hyperglycaemia and ketoacidosis has been developed using a continuous intravenous infusion of insulin at a rate of 2.4 U/hr to maintain serum insulin concentration at physiological levels. This rate raises the mean serum insulin to 83 muU/ml and has a therapeutic effect which is not augmented by higher infusion rates. The response to such low doses of insulin indicates a need for a reappraisal of currently held theories about insulin resistance in diabetic ketoacidosis. In 11 diabetic patients with a mean plasma glucose of 514 mg/100 ml this therapy produced continuous falls in plasma glucose at a mean rate of 75 mg/100 ml/hr, and 10 out of 11 patients recovered within eight hours. This form of therapy is simple to institute, not complicated by hypoglycaemia, and avoids the confusion and empiricism of previously described forms of therapy.

A focus of Rocky Mountain spotted fever within New York City

In the spring and summer of 1987, four persons acquired Rocky Mountain spotted fever within New York City, an area in which the disease had not previously been known to be endemic. Three of the four patients were residents of the Soundview area of the Bronx. All diagnoses were confirmed by indirect fluorescent-antibody tests. Environmental investigation revealed that the tick vector for Rickettsia rickettsii, Dermacentor variabilis, was present in a local park. Of the 66 specimens of D. variabilis collected, 5 (8 percent) were positive for rickettsiae from the spotted fever group. Of an additional 96 specimens of D. variabilis, 5 (5 percent) were found positive for rickettsiae by a more specific monoclonal antibody assay. Eight additional New York City parks in all five boroughs were searched for ticks. D. variabilis was found in only one other park; of the 147 ticks collected there, none were positive for rickettsiae. These findings emphasize the focal nature of Rocky Mountain spotted fever and the need to consider that disease in the differential diagnosis of any obscure acute febrile illness, even in the absence of a history of travel to known endemic areas.

Attainment of metabolic goals in the integrated UK islet transplant program with locally isolated and transported preparations

The objective was to determine whether metabolic goals have been achieved with locally isolated and transported preparations over the first 3 years of the UK's nationally funded integrated islet transplant program. Twenty islet recipients with C-peptide negative type 1 diabetes and recurrent severe hypoglycemia consented to the study, including standardized meal tolerance tests. Participants received a total of 35 infusions (seven recipients: single graft; 11 recipients: two grafts: two recipients: three grafts). Graft function was maintained in 80% at [median (interquartile range)] 24 (13.5-36) months postfirst transplant. Severe hypoglycemia was reduced from 20 (7-50) episodes/patient-year pretransplant to 0.3 (0-1.6) episodes/patient-year posttransplant (p < 0.001). Resolution of impaired hypoglycemia awareness was confirmed [pretransplant: Gold score 6 (5-7); 24 (13.5-36) months: 3 (1.5-4.5); p < 0.03]. Target HbA1c of <7.0% was attained/maintained in 70% of recipients [pretransplant: 8.0 (7.0-9.6)%; 24 (13.5-36) months: 6.2 (5.7-8.4)%; p < 0.001], with 60% reduction in insulin dose [pretransplant: 0.51 (0.41-0.62) units/kg; 24 (13.5-36) months: 0.20 (0-0.37) units/kg; p < 0.001]. Metabolic outcomes were comparable 12 months posttransplant in those receiving transported versus only locally isolated islets [12 month stimulated C-peptide: transported 788 (114-1764) pmol/L (n = 9); locally isolated 407 (126-830) pmol/L (n = 11); p = 0.32]. Metabolic goals have been attained within the equitably available, fully integrated UK islet transplant program with both transported and locally isolated preparations.

Motivational versus confrontational interviewing: a comparison of substance abuse assessment practices at employee assistance programs

The aim of this study was to conduct a quasi-experimental comparison of two employee assistance program (EAP) assessment approaches with substance abusers: confrontational interviewing (CI) and motivational interviewing (MI). A total of 176 EAP clients from 14 study sites met the study criteria, and 89 (51%) agreed to participate in the study. At three and nine months postassessment, both the MI and CI groups showed similar changes in readiness for change, completion of initial treatment plans, and subsequent treatment. Most important, both the MI and CI participants showed significant and comparable improvement on all of the substance abuse baseline measures as well as measures of family-social well-being and effects of drinking/drugging on work performance. The results open the door for EAP counselors to use an empirically supported assessment style that is at least as effective as the traditional confrontational approach.

A consensus sequence for long-chain fatty-acid alcohol oxidases from Candida identifies a family of genes involved in lipid omega-oxidation in yeast with homologues in plants and bacteria

The yeast Candida cloacae is capable of growing on alkanes and fatty acids as sole carbon sources. Transfer of cultures from a glucose medium to one containing oleic acid induced seven proteins of M(r) 102,000, 73,000, 61,000, 54,000, and 46,000 and two in the region of M(r) 45,000 and repressed a protein of M(r) 64,000. The induction of the M(r) 73,000 protein reached a 7-fold maximum 24 h after induction. The protein was confirmed by its enzyme activity to be a long-chain fatty-acid alcohol oxidase (LC-FAO) and purified to homogeneity from microsomes by a rapid procedure involving hydrophobic chromatography. An internal peptide of 30 amino acids was sequenced. A 1100-base pair cDNA fragment containing the LC-FAO peptide coding sequence was used to isolate a single exon genomic clone containing the full-length coding sequence of an LC-FAO (fao1). The fao1 gene product was expressed in Escherichia coli and was translated as a functional long-chain alcohol oxidase, which was present in the membrane fraction. In addition, full-length coding sequences for a Candida tropicalis LC-FAO (faoT) and a second C. cloacae LC-FAO (fao2) were isolated. The DNA sequences obtained had open reading frames of 2094 (fao1), 2091 (fao2), and 2112 (faoT) base pairs. The derived amino acid sequences of fao2 and faoT showed 89.4 and 76.2% similarities to fao1. The fao1 gene is much more highly induced on alkane than is fao2. Although this study describes the first known DNA sequences encoding LC-FAOs from any source, there are unassigned Arabidopsis sequences and an unassigned Mycobacterium sequence in the GenBank(TM) Data Bank that show strong homology to the described LC-FAO sequences. The conservation of sequence between yeast, plants, and bacteria suggests that an as yet undescribed family of long-chain fatty-acid oxidases exists in both eukaryotes and prokaryotes.

Diel foraging behavior of gravid leatherback sea turtles in deep waters of the Caribbean Sea

It is generally assumed that leatherback turtles (Dermochelys coriacea), like other species of sea turtle, do not feed while offshore from nesting beaches, and rely instead on fat reserves to fuel reproductive activities. Recent studies, however, provide evidence that leatherbacks may forage during the internesting interval while offshore in the Western Atlantic Ocean and Caribbean Sea. Bio-logging technology was used to investigate the foraging behavior of female leatherback turtles at St Croix, US Virgin Islands. Leatherback gastrointestinal tract temperatures (TGT) were analyzed for sudden fluctuations indicative of ingestions, and laboratory ingestion simulations were used to characterize temperature fluctuations associated with ingestion of prey versus seawater. Dive patterns associated with prey ingestion were characterized and the proportion of prey ingestion during the day (05:00–18:59 h) and night (19:00–04:59 h) were compared. A combined total of 111 prey ingestions for seven leatherback turtles were documented during the internesting interval. The number of prey ingestions ranged from six to 48 for individual turtles, and the majority (87.4%) of these events occurred during the daytime. Prey ingestions were most frequently associated with V-shaped dives, and the mean (±1 s.d.) maximum dive depth with prey ingestion ranged from 154±51 to 232±101 m for individual turtles. Although leatherbacks were found to opportunistically feed during the internesting interval, the low prey ingestion rates indicate that energy reserves acquired prior to the breeding season are critical for successful reproduction by leatherbacks from the St Croix, USVI nesting population.

Flavor Ratio of Astrophysical Neutrinos above 35 TeV in IceCube

A diffuse flux of astrophysical neutrinos above 100 TeV has been observed at the IceCube Neutrino Observatory. Here we extend this analysis to probe the astrophysical flux down to 35 TeV and analyze its flavor composition by classifying events as showers or tracks. Taking advantage of lower atmospheric backgrounds for showerlike events, we obtain a shower-biased sample containing 129 showers and 8 tracks collected in three years from 2010 to 2013. We demonstrate consistency with the (fe:fμ:fτ)⊕≈(1:1:1)⊕ flavor ratio at Earth commonly expected from the averaged oscillations of neutrinos produced by pion decay in distant astrophysical sources. Limits are placed on nonstandard flavor compositions that cannot be produced by averaged neutrino oscillations but could arise in exotic physics scenarios. A maximally tracklike composition of (0:1:0)⊕ is excluded at 3.3σ, and a purely showerlike composition of (1:0:0)⊕ is excluded at 2.3σ.