Study of the K_{L}→π

The rare decay K_{L}→π^{0}νν[over ¯] was studied with the dataset taken at the J-PARC KOTO experiment in 2016, 2017, and 2018. With a single event sensitivity of (7.20±0.05_{stat}±0.66_{syst})×10^{-10}, three candidate events were observed in the signal region. After unveiling them, contaminations from K^{±} and scattered K_{L} decays were studied, and the total number of background events was estimated to be 1.22±0.26. We conclude that the number of observed events is statistically consistent with the background expectation. For this dataset, we set an upper limit of 4.9×10^{-9} on the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level.

Search for K_{L}→π

A search for the rare decay K_{L}→π^{0}νν[over ¯] was performed. With the data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01_{stat}±0.14_{syst})×10^{-9} was achieved and no candidate events were observed. We set an upper limit of 3.0×10^{-9} for the branching fraction of K_{L}→π^{0}νν[over ¯] at the 90% confidence level (C.L.), which improved the previous limit by almost an order of magnitude. An upper limit for K_{L}→π^{0}X^{0} was also set as 2.4×10^{-9} at the 90% C.L., where X^{0} is an invisible boson with a mass of 135 MeV/c^{2}.

PAPNET computer-aided rescreening for detection of benign and malignant glandular elements in cervicovaginal smears: a review of 61 cases.

An increasing proportion of the recent cytodiagnostic literature has focused on automation of the Pap smear screening process in hopes of finding a feasible system to aid in the reduction of the number of reported false-negative cases. In a sense, these systems can be thought of as computer-driven sensitivity enhancers for better detection of abnormalities in smeared cervicovaginal specimens. The PAPNET system (Neuromedical Systems, Inc., Suffern, NY) relies on a neural network of artificial-intelligence technology to recognize the complex cellular arrays present in Pap smears, and was originally intended to aid in the identification of morphologically abnormal cells of squamous origin. Herein, we present the results of 61 smears containing a mixture of known diagnostically important benign, dysplastic, and malignant glandular cellular abnormalities which were reviewed by the PAPNET technology. The PAPNET system detected the diagnostic glandular material in 44 of the 45 benign cases reviewed (98% detection rate). In addition, the PAPNET technology identified abnormal cellular material in 15 of the 16 studied smears from patients with malignant/dysplastic morphology (94% detection rate). These data indicate that the PAPNET neural networks are capable of detecting cells with aberrant glandular cytomorphology. In both cases missed by the PAPNET system, the number of abnormal cells per slide was very low, indicating that as with human screeners, the capabilities of this semiautomated method may be exceeded when an extreme paucity of diagnostic cellular material is present in a given slide. Further and larger reviews of glandular abnormalities by automated technologies are needed to assess these systems for their true efficacy at diminishing false-negative cases.

Effect of blood transfusions on macrophage-lymphocyte interaction in an animal model.

Blood transfusions have been reported over the last 2 decades to decrease allograft rejection, to increase the rate of tumor growth, and to increase susceptibility to infectious complications. The effect of transfusions on macrophages, specifically on their regulation of lymphocyte proliferation, was investigated. Both macrophages and their supernatants obtained from transfused rats impaired lymphocyte blastogenesis to a greater degree than those from nontransfused rats. This effect was greatest when the lymphocytes were subjected to mitogen stimulation. The immunosuppression was seen with macrophages from both allogeneically and syngeneically transfused rats. Blood transfusions exert their immunosuppressive effect at least in part by increasing macrophage suppression of lymphocyte response to stimuli.

The effects of EHDP on regenerating trabecular bone using in vivo microscopic, light and electron microscopic, and electron microprobe techniques.

Metallic chambers were implanted into the proximal tibiae of rabbits to permit microscopic examination of living bone in situ. The bone repair process secondary to the injury produced during installation of the chamber, was visualized. Six to 8 weeks after implantation, osteoid and/or bone could be seen. The effects of various doses of disodium ethane-1-hydroxy-1, 1-diphosphonate (EHDP) on the repair and regeneration processes following chamber implantation were studied. Data from various techniques indicated that: (1) following low dose EHDP (0.25 mg/kg/day) chambers contained bone tissue morphologically and ultrastructurally indistinguishable from controls; and (2) with higher doses of EHDP (2.5 or 10 mg/kg/day) chamber contained spicules of normal osteoid, osteoblasts and osteocytes, but were devoid of osteoclasts. The effects of the various regimes of EHDP also were assessed on regenerated, trabecular bone contained within the tibia chambers three months after implantation of the chambers. Data from various methods of analysis supported the following conclusions: (1) the low dose of EHDP (0.25 mg/kg/day) had no toxic effects on the trabecular bone within the chambers but there appeared to be an increase in bone formation as compared to saline control; (2) higher doses of EHDP (2.5 or 10mg/kg/day) were not toxic to bone cells but thick osteoid seams formed on the trabecular bone within the chambers. No osteoclasts were found associated with the bone apparently due to the coverage of bone surfaces by osteoid seams; and (3) osteoid which accumulated after EHDP treatment of 2.5 mg/kg/day for 2 months remained uncalcified for as long as 2 months following withdrawal of EHDP administration. The results showed the value of tibial chamber for examining microscopically living bone in situ and demonstrated the inhibitory effect of EHDP on mineralization of newly formed osteoid and a lack of effect on bone cells.