Pharmacokinetics of NS-105, a novel cognition enhancer. 1st communication: absorption, metabolism and excretion in rats, dogs and monkeys after single administration of 14C-NS-105

The absorption, metabolism and excretion of NS-105 ((+)-5-oxo-D-prolinepiperidinamide monohydrate, CAS 110958-19-5), a novel cognition enhancer, were studied in rats, dogs and monkeys after intravenous or oral administration of 14C-NS-105. The protein binding of this drug was also investigated in vivo and in vitro. After the intravenous and oral administrations of 14C-NS-105, the unchanged drug accounted for most of the plasma radioactivity in all the species tested. After the intravenous injection, the plasma concentration of NS-105 decreased monoexponentially with respective elimination half-lives of 0.67, 2.1 and 1.3 h for the rats, dogs and monkeys. After the oral administration, the plasma concentration of NS-105 reached a maximum within 1 h, then decreased as in intravenous administration in all the species tested. NS-105 was almost completely absorbed from the small intestine, and first-pass metabolism was very limited. As a result, its systemic availability was high; 97% in the rats, 90% in the dogs and 79% in the monkeys. No significant sex-related differences in the plasma concentration profiles of radioactivity were observed in the rats after the oral administration of 14C-NS-105 (p > 0.05). Food affected the absorption of NS-105. The Cmax and AUC0-infinity of radioactivity concentration were proportional to the dose for 1-100 mg/kg of 14C-NS-105. There were no marked differences between the intravenous and oral routes in the compositions of urinary radioactivity for any of the species tested. In the urine of dogs, LAM-162 (oxidative metabolite with C-N cleavage of the piperidine ring), LAM-79 (metabolite with 4-hydroxylated piperidine ring), LAM-163 (metabolite with 3-hydroxylated piperidine ring) and M1 (not identified) accounted for 20%, 3%, 6% and 1% of the urinary radioactivity, respectively. In the urine of rats and monkeys, LAM-162 and LAM-79 accounted for 1-6% of the urinary radioactivity, but LAM-163 and M1 were not detected. After the intravenous and oral administrations, NS-105 was primarily eliminated by renal excretion in all the species tested, approximately 90% of the dose being excreted unchanged in the urine for rats and monkeys and 60% of it for dogs. Excretions of radioactivity in the bile and exhaled air in rats were less than 1.4% of the dose, and lymphatic absorption of radioactivity was only 0.3% of the dose. The percentage of 14C-NS-105 bound to serum proteins was less than 3.3% in all the animal species tested, including humans.     

Development and assessment of the pharmaceutical management and guidance services for inpatients considering clinical value and economy]

We developed pharmaceutical management and guidance services for inpatients in a ward of circulatory medicine, considering clinical and economical standpoints. In these services, pharmacists deliver drugs prescribed for inpatients with individual drug information papers, explain to them about their drugs using information papers and give counsel. Since most of the patients were aged people, developing many kinds of diseases and taking many kinds of drugs, they had many problems such as lack of knowledge of the effects of drugs. First, we surveyed views of patients, physicians and nurses on these services. Consequently, all of them advised us that "pharmacists should explain to patients about the prescribed drugs using information papers." The patients preferred pharmacists as expositors of drugs to physicians or nurses. The physicians considered that "pharmacists have to attach importance to clinical information and package-inserts of drugs and explain to patients about drug information using pamphlet in response to the understanding of patients." The nurses wanted to cooperate with pharmacists in "improving medication compliance." On the basis of these views, we improved our services. Next, we made a survey of patients' knowledge about their drugs. We found that in the patients the level of knowledge concerning "ways," "effects" and "reasons" of taking drugs and that of "compliance" and "satisfaction in taking drugs" were improved through these services. The patients reentered in the hospital kept a high level. The ratio of patients taking drugs by themselves increased. Last, we also applied this method to wards of "blood and collagen diseases" and "pediatrics." The demand for these services increased smoothly. We compared these services based on our method with all other services by hospital pharmacists from the viewpoint of economy. We found that only our service method was beneficial.     

Delayed image of iodine-123 iomazenil as a relative map of benzodiazepine receptor binding: The optimal scan time

Delayed single-photon emission tomograpic (SPET) images after an intravenous bolus injection of iodine-123 iomazenil have been used as a relative map of benzodiazepine receptor binding. We determined the optimal scan time for obtaining such a map and assessed the errors of the map. SPET and blood data from six healthy volunteers and five patients were used. A three-compartment kinetic model was employed in simulation studies and analyses of actual data. The simulation studies suggested that, in the normal brain, the scan time at which a single SPET image best represented the relative receptor binding was 3.0–3.5 h post-injection. This finding was supported by actual data from the volunteers. The simulation studies also suggested that the optimal scan time was not greatly changed by the variability of the input functions, and that the error in the SPET image contrast in the vicinity of the optimal scan time was not increased by changes in the tracer kinetics in the entire brain. The SPET image contrast in the patients at 3.0 h post-injection agreed well with the reference receptor binding estimated by kinetic analysis, with a mean error of 3.6%. These findings support the use of a single SPET image after bolus injection of [¹²³I]iomazenil as a relative map of benzodiazepine receptor binding. For this purpose, a SPET scan time of 3.0-3.5 h post-injection is recommended.     

A highly predictable animal model of retinoblastoma

Summary A new animal model of retinoblastoma was developed in newborn inbred CDF rats by intravitreous inoculation of retinal tumor cells (5×10⁴/5 l) derived from the cultured tumor cell line EXP-5. The retinal tumor from which the cell line originated was induced by a single intravitreous inoculation of human adenovirus serotype 12 (5 l of 10⁸ TCID 50/0.1 ml) in syngeneic rats. Within 1 month after intravitreous moculation of EXP-5 cells, a clinically recognizable ocular tumor was obtained in all 39 rats. Ad 12-specific T-antigens were demonstrated in the cultured tumor cells using immunofluorescent techniques. Morphologically these tumor cells closely resembled retinoblastuma, with poorly differentiated intracytoplasmic organelles, solitary cilia with a 9+0 tubule pattern, and abnormal nuclear membrane associated with a set of basal bodies. The significance of this highly manipulable retinal tumor cell line is the capability of providing a full-fledged intravitreous tumor in 1-month-old CDF rats, whose actual life span is known to be 42 months. Transplantable retinal tumors described to date are reviewed breifly and compared with the presently reported cell line.Supported by USPHS grants EY-CA01667, R01-EY-03171, and P30 EY-01784, by grants from the Retina Research Foundation, Houston, Texas, and by the Massachusetts Lions Eye Research Fund Inc.     

Dynamic regulation of middle cerebral artery blood flow velocity in aging and hypertension

BACKGROUND AND PURPOSE: Although aging and hypertension may predispose hypertensive elderly subjects to cerebral hypoperfusion during orthostatic stress, their effects on the acute cerebral autoregulatory response to hypotension are not known. METHODS: Continuous middle cerebral artery blood flow velocity (BFV) (transcranial Doppler ultrasound) and mean arterial pressure (MAP, Finapres) were measured in response to (1) acute hypotension during standing, (2) steady-state sitting and standing, and (3) hypercarbia during CO(2) rebreathing in 10 healthy young subjects (age 24+/-1 years), 10 healthy elderly subjects (age 72+/-3 years), and 10 previously treated hypertensive elderly (age 72+/-2 years) subjects. CO(2) reactivity was computed as the slope of cerebrovascular conductance (CVC=BFV/MAP) versus end-expiratory CO(2). Coherence, transfer magnitudes, and phases between low-frequency MAP and BFV signals were computed from their autospectra during 5 minutes of sitting and standing. RESULTS: MAP fell to a similar extent in all groups by an average of 21 to 26 mm Hg (22% to 26%) within 30 seconds of standing. Mean BFV also fell in all subjects but significantly less in the older subjects (-4.7+/-0. 7 cm/s in hypertensives and -5.3+/-1.2 cm/s in normotensives, P=NS) compared with younger subjects (-10.1+/-1.1 cm/s, P<0.05). CO(2) reactivity was greater in the young subjects (0.19+/-0.01) compared with normotensive (0.14+/-0.01, P<0.05) and hypertensive elderly subjects (0.11+/-0.02, P<0.05) (P=NS between elderly groups). Fewer hypertensive subjects had coherence between MAP and BFV signals; for subjects with coherence, there were no significant group differences in phase or transfer magnitudes in either sitting or standing positions. CONCLUSIONS: Despite reduced CO(2) reactivity, elderly normotensive and previously treated hypertensive subjects retain cerebral autoregulatory capacity in response to acute orthostatic hypotension.     

Early characteristic findings in bowleg deformities: evaluation using magnetic resonance imaging

We used magnetic resonance imaging (MRI) to evaluate bowleg deformities in infancy. Twenty-five tibiae of 13 infants were examined and divided into two groups based on MRI findings: group A had high intensity area in the medial epiphyseal cartilage on T2-weighted images. Group B had depression of medial physis and abnormal signal in the perichondrial region in addition to the epiphyseal lesion. At the final follow-up, all cases in group A demonstrated normal lower leg alignments, whereas five cases in group B showed characteristic roentogenographic findings of Blount's disease. The improvement rate of metaphyseal-diaphyseal angle was correlated with this classification. These findings suggested that abnormal findings in physis and perichondrial region might be preliminary findings in early stage of Blount's disease. The high intensity areas in the medial epiphyseal cartilage were commonly found among the cases with bowing deformities, which suggested that there might be a common pathomechanism between physiologic bowing and infantile Blount's disease.     

The role of the sentinel lymph node in gastrointestinal cancer

Evaluation of the clinical significance of the sentinel node concept in GI cancer has just begun. The authors' preliminary data, using intraoperative radiation techniques and the gamma probe, suggest that it is worthwhile to continue the evaluation of this procedure to determine its role in an accurate staging and a minimally invasive approach to GI cancers.