A Deep Learning Approach to Photoacoustic Wavefront Localization in Deep-Tissue Medium.

Optical photons undergo strong scattering when propagating beyond 1-mm deep inside biological tissue. Finding the origin of these diffused optical wavefronts is a challenging task. Breaking through the optical diffusion limit, photoacoustic (PA) imaging (PAI) provides high-resolution and label-free images of human vasculature with high contrast due to the optical absorption of hemoglobin.

Light-Emitting-Diode-Based Multispectral Photoacoustic Computed Tomography System.

Photoacoustic computed tomography (PACT) has been widely explored for non-ionizing functional and molecular imaging of humans and small animals. In order for light to penetrate deep inside tissue, a bulky and high-cost tunable laser is typically used. Light-emitting diodes (LEDs) have recently emerged as cost-effective and portable alternative illumination sources for photoacoustic imaging.

A Single Simulation Platform for Hybrid Photoacoustic and RF-Acoustic Computed Tomography.

In recent years, multimodal thermoacoustic imaging has demonstrated superior imaging quality compared to other emerging modalities. It provides functional and molecular information, arising due to electromagnetic absorption contrast, at ultrasonic resolution using inexpensive and non-ionizing imaging methods. The development of optical- as well as radio frequency (RF)-induced thermoacoustic imaging systems would benefit from reliable numerical simulations.

Evaluation of the patient with chronic cough.

Patients with chronic cough should avoid exposure to irritants that can trigger cough, and those who smoke should stop smoking. Patients who develop chronic cough in association with angiotensin-converting enzyme inhibitor therapy should be switched to an agent from another drug class. If cough persists, a chest radiograph should be ordered to rule out malignancy and other serious conditions.

Neurohypophyseal vasopressin in the Syrian hamster: response to short photoperiod, pinealectomy, melatonin treatment, or osmotic stimulation.

In the present study, the effect of photoperiod on vasopressin content in the pituitary neurointermediate lobe (NIL), as well as the ability of pinealectomy to prevent and melatonin to mimic the short photoperiod-induced changes in NIL vasopressin were studied in male Syrian hamsters. The ability of melatonin to modify the hyperosmotically stimulated vasopressin release was also determined. Exposure to short photoperiod (SD) for 4 or 10 weeks increased vasopressin content in the hamster NIL.

Effects of streptozotocin-induced diabetes on the response of male rats to immobilization stress.

The effects of streptozotocin-induced (STZ) diabetes on the response to immobilization stress were evaluated in adult male rats. Rats were injected with STZ or vehicle and handled daily to minimize stress. Four weeks later, half of the animals were lightly anesthetized with ether and immobilized for 20 min.

The effects of short photoperiod, pinealectomy, and melatonin treatment on oxytocin synthesis and release in the male syrian hamster.

The pineal gland has been shown to affect plasma oxytocin (OT) levels, but the mechanism of this action is not apparent. In the present study, the ability of the photoperiod to affect plasma OT levels, neurointermediate lobe (NIL) OT content, and hypothalamic OT mRNA levels was studied in male Syrian hamsters. In addition, the ability of pinealectomy to prevent and melatonin (MEL) to mimic the short photoperiod-induced changes were also determined.

Oxytocin and prolactin release after hypertonic saline administration in melatonin-treated male Syrian hamsters.

The aim of the present investigations was to examine the effects of melatonin (Mel) on oxytocin (OT) release under conditions of osmotic stimulation, brought about by hypertonic saline administration, as well as to determine whether osmotically stimulated OT release in Mel-treated Syrian hamster is associated with alterations in the release of prolactin (PRL) and in norepinephrine (NE) and dopamine (DA) content in the hypothalamus. In both Mel- and vehicle-treated hamsters, injection of hypertonic saline was followed by a significant decrease in OT content in the pituitary neurointermediate lobe (NIL) and elevation of plasma OT and PRL levels. Melatonin injections had no significant affect on NIL OT content in either isotonic- or hypertonic-saline treated animals.

Photoperiod effects on neurohypophyseal and tuberoinfundibular dopamine metabolism in the male hamster.

Exposure of golden hamsters to a short photoperiod (< 12.5 h light/day) leads to suppression of gonadal function secondary to reduced gonadotropin and PRL secretion. PRL secretion is decreased despite a reduction of tuberoinfundibular dopaminergic activity.

Infertility in transgenic mice overexpressing the bovine growth hormone gene: disruption of the neuroendocrine control of prolactin secretion during pregnancy.

Transgenic female mice overexpressing the bovine growth hormone (bGH) gene with the phosphoenolpyruvate carboxykinase (PEPCK) promoter exhibit severe reproductive deficits. Although these animals ovulate and conceive normally, pregnancy is arrested due to luteal failure, leading to the loss of embryos during early gestation. The results of replacement therapy suggested that luteal failure was secondary to prolactin (PRL) deficiency.

Sertoli cells in testes containing or lacking germ cells: a comparative study of paracrine effects using the W (c-kit) gene mutant mouse model.

Background: Paracrine effects of germ cells on Sertoli cell structure were examined in a mouse model with the W locus (dominant white spotting) mutation in which animals with the W/Wv genotype (referred to as mutants) lack virtually all germ cells.

Results: Morphometric determination of Sertoli cell parameters in mutant and control (+/+) animals showed that although the testes of mutant animals were about eight times smaller than controls, the numbers of Sertoli cells in the two groups did not differ. Sertoli cell volume, Sertoli cell cytoplasmic and nuclear volumes, and Sertoli cell surface area in mutant animals were significantly smaller than in control animals.

Diabetes disrupts copulatory behavior and neuroendocrine responses of male rats to female conspecifics.

Streptozotocin-induced diabetes disrupts copulatory behavior in the male rat. The increase in serum luteinizing hormone (LH) that occurs in the male rat in response to the presence of a receptive female is absent in most diabetic rats. A female-induced testosterone rise is not seen in diabetic male rats, including those showing an increase in LH.

Streptozotocin-induced diabetes blocks the positive feedback release of luteinizing hormone in the female rat.

The effects of streptozotocin-induced (STZ) diabetes on the release of gonadotropins was studied in female rats. In the first experiment, rats were ovariectomized and 2 days later were injected with STZ. Three weeks later rats were treated with estrogen and progesterone and blood samples were taken via intraatrial cannulae for luteinizing hormone (LH) assay.

Influence of diabetes on the gonadotropin response to the negative feedback effect of testosterone and hypothalamic neurotransmitter turnover in adult male rats.

The influence of diabetes on the gonadotropin response to the negative feedback effect of testosterone (T) and hypothalamic neurotransmitter turnover rates in adult male rats was evaluated. Adult male Sprague-Dawley rats were made diabetic by an intraperitoneal injection of streptozotocin (STZ; 5 mg/100 g body weight) in citrate buffer. Vehicle-injected rats served as controls.