Thermoneutral conditions correct the obese phenotype in female, but not male, Kiss1r knockout mice.

Kisspeptin, a neuropeptide that activates gonadotropin-releasing hormone (GnRH) neurons, has also been implicated as a regulator of energy balance. Kisspeptin receptor (Kiss1r) knockout (KO) mice display an obese phenotype in adulthood compared to wild-type (WT) controls due to reduced energy expenditure. Additionally, experimental evidence shows that the temperature of typical rodent housing conditions (22 °C) increases the metabolism of mice above basal levels. Female Kiss1r KO mice show reduced core temperature and impaired temperature adaptation to an acute cold challenge, suggesting their temperature homeostasis processes are altered. The present study examined the phenotype of gonadectomised Kiss1r KO mice at both sub-thermoneutral and thermoneutral temperature (22 °C and 30 °C). Our results confirmed the obese phenotype in Kiss1r KO mice at 22 °C, and revealed a sexually dimorphic effect of thermal neutrality on the phenotype. In female KO mice, the obesity observed at 22 °C was attenuated at 30 °C. Plasma leptin levels were higher in KO than WT female mice at 22 °C (P < 0.001) but not at 30 °C. Importantly, the expression of Ucp1 mRNA in brown adipose tissue was lower in KO mice compared to WT mice at 22 °C (P < 0.05), but not different from WT at 30 °C. In male KO mice, a metabolic phenotype was observed at 22 °C and 30 °C. These results provide further evidence for kisspeptin-mediated regulation of adiposity via altered energy expenditure. Moreover, thermoneutral housing alleviated the obese phenotype in female Kiss1r KO mice, compared to WT, indicating the impairment in these mice may relate to an inability to adapt to the chronic cold stress that is experienced at 22 °C.

A case of hypersensitivity to progesterone presenting as an eczematous eruption.

Hypersensitivity to progesterone is a rare condition, and it represents a hypersensitivity reaction to endogenous progesterone. Here we report a case of a woman who presented to our attention for evaluation of a rash for a few years on her posterior elbows, forearms, and right lateral lower extremity. We report this case because it describes a rare clinical entity, with an atypical clinical presentation pemphigoid-like, that is rarely described in literature.

Gamma ray measurements with photoconductive detectors using a dense plasma focus.

Photons in the MeV range emitted from the dense plasma focus (DPF) at the NSTec North Las Vegas Facility have been measured with both neutron-damaged GaAs and natural diamond photoconductive detectors (PCDs). The DPF creates or "pinches" plasmas of various gases (e.g., H2, D2, Ne, Ar., etc.) that have enough energy to create MeV photons from either bremsstrahlung and/or (n,n(')) reactions if D2 gas is used. The high bandwidth of the PCDs enabled the first ever measurement of the fast micro-pinches present in DPF plasmas. Comparisons between a slower more conventional scintillator/photomultiplier tube based nuclear physics detectors were made to validate the response of the PCDs to fast intense MeV photon signals. Significant discrepancies in the diamond PCD responses were evident.

High energy photocathodes for laser fusion diagnostics.

Laser fusion experiments at the National Ignition Facility require time-resolved x-ray images of the ignition target self-emission. The photon energies are expected to be greater than 10 keV. Photoemission quantum yield measurement data and photoelectron energy spectrum data are presently unavailable in this photon energy range, but are essential in the design of x-ray imaging diagnostics. We developed an apparatus to measure the quantum efficiency of primary and secondary photoelectron emission and to estimate the energy spectrum of the secondary photoelectrons. The apparatus has been tested using photon energies less than 10 keV to allow comparisons with prior work. A method for preparing photocathodes with geometrically enhanced photoefficiency has been developed.

Photoconductive detectors with fast temporal response for laser produced plasma experiments.

Processes during laser plasma experiments typically have time scales that are less than 100 ps. The measurement of these processes requires x-ray detectors with fast temporal resolution. We have measured the temporal responses and linearity of several different x-ray sensitive photoconductive detectors (PCDs). The active elements of the detectors investigated include both diamond (natural and synthetic) and GaAs crystals. The typical time responses of the GaAs PCDs are approximately 60 ps, respectively. Some characterizations using x-ray radiation from a synchrotron radiation source are presented.

A 160-femtosecond optical image processor based on a conjugated polymer.

Degenerate ground-state conjugated polymers exhibit large third-order nonlinear optical susceptibilities, including substantial two-photon absorption. With the use of a machine architecture suited to these material properties, ultrafast optical processors are possible. A four-wave mixing optical correlator was built with an air-stable, processable, degenerate ground-state conjugated polymer, poly(1,6-heptadiester). The continuously updatable processor correlates two 5000-pixel images in less than 160 femtoseconds, achieving peak processing rates of 3 x 10(16) operations per second.

Evaluation of low-dose estrogen and progestin therapy in postmenopausal women. A double-blind, prospective study of sequential versus continuous therapy.

In this prospective, double-blind study, we evaluated the efficacy and safety of low-dose estrogen and progestin replacement therapy in 36 postmenopausal women who were administered oral medroxyprogesterone acetate (MPA) cyclically or continuously in combination with conjugated equine estrogen (CEE) 0.625 mg daily. In the sequential group, MPA (5.0 mg) was administered daily for 12 days of each 25-day treatment cycle. In the two continuous groups, MPA was administered without interruption at a daily dose of either 2.5 mg or 5.0 mg for 12 treatment cycles. Of the 36 women in the study, 29 women completed the one-year protocol. The clinical and metabolic responses were assessed before and every three cycles during the 12 cycles of treatment. Endometrial biopsies and lumbar bone density scans were performed before and during the last week of the 12th treatment cycle. Vasomotor and urogenital symptoms improved in all women. Cyclic menstrual bleeding occurred in all patients on sequential therapy, and proliferative endometrium was noted in two of these women. All patients in both continuous treatment groups experienced amenorrhea after the fifth cycle of therapy, and all endometrial biopsies were atrophic or inactive. From the 3rd through the 12th month of cycle, favorable lipid and lipoprotein changes occurred in all treatment groups. Lumbar bone mineral density improved significantly (P < .05) by an average of 6.41% in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)