Maturation and long-term hypoxia alters Ca2+-induced Ca2+ release in sheep cerebrovascular sympathetic neurons.

The contribution of sympathetic nerves arising from the superior cervical ganglia (SCG) toward the growth and function of cerebral blood vessels is pertinent throughout maturation as well as in response to cardiovascular stress imposed by high-altitude long-term hypoxia (LTH). The function of SCG sympathetic neurons is dependent on intracellular Ca2+ concentration ([Ca2+]i) signaling, which is strongly influenced by a process known as Ca(2+)-induced Ca2+ release (CICR) from the smooth endoplasmic reticulum (SER). In this study, we used the sheep SCG neuronal model to test the hypotheses that maturation decreases CICR and high-altitude LTH depresses CICR in fetal SCG neurons but not in those of the adult.

Advancing age alters the contribution of calcium release from smooth endoplasmic reticulum stores in superior cervical ganglion cells.

Unlabelled: In superior cervical ganglion (SCG) neurons calcium-induced calcium release (CICR), mediated by ryanodine receptors (RyRs), contributes to stimulation-evoked intracellular calcium ([Ca(2+)](i)) transients.

Hypothesis: The contribution of CICR to electrical field stimulation (EFS)-evoked [Ca(2+)](i) transients in SCG cells declines with senescence and may be partially recovered in the presence of caffeine. We measured EFS-evoked [Ca(2+)](i) transients in isolated fura-2-loaded SCG cells from Fischer-344 rats aged 6, 12, and 24 months with either the RyR antagonist ryanodine to block the contribution of CICR to [Ca(2+)](i) transients or caffeine to sensitize CICR to EFS.

Age-dependent changes in Ca2+ homeostasis in peripheral neurones: implications for changes in function.

Calcium ions represent universal second messengers within neuronal cells integrating multiple cellular functions, such as release of neurotransmitters, gene expression, proliferation, excitability, and regulation of cell death or apoptotic pathways. The magnitude, duration and shape of stimulation-evoked intracellular calcium ([Ca2+]i) transients are determined by a complex interplay of mechanisms that modulate stimulation-evoked rises in [Ca2+]i that occur with normal neuronal function. Disruption of any of these mechanisms may have implications for the function and health of peripheral neurones during the aging process.

Advancing age alters the expression of the ryanodine receptor 3 isoform in adult rat superior cervical ganglia.

Sympathetic nerves arising from the superior cervical ganglion (SCG) protect the cerebrovasculature during periods of acute hypertension and may play a role in homeostasis of target organs. The functions of these nerves depend on calcium release triggered by activation of ryanodine receptor (RyR) channels. The function of RyR channels is in part dependent on genetic expression and regulation by numerous protein modulators such as neuronal nitric oxide synthase (nNOS) neurons also found in the SCG.

Advancing age alters rapid and spontaneous refilling of caffeine-sensitive calcium stores in sympathetic superior cervical ganglion cells.

Intracellular calcium concentration ([Ca2+]i) release from smooth endoplasmic reticulum (SER) stores plays an important role in cell signaling. These stores are rapidly refilled via influx through voltage-gated calcium channels or spontaneously via store-operated calcium channels and subsequent pumping by SER Ca2+-ATPases. We measured [Ca2+]i transients in isolated fura 2-loaded superior cervical ganglion cells from 6-, 12-, 20-, and 24-mo-old Fischer 344 rats.

Tumor necrosis factor-alpha: a marker for peritoneal adhesion formation.

This study investigates the possible correlation between higher levels of tumor necrosis factor-alpha (TNF-alpha) and higher rates of adhesion formation following standard bowel injury. Forty-five Sprague-Dawley rats were divided into three equal groups. Blood was obtained from all rats preoperatively.

A new minimally invasive technique for cholecystectomy. Subxiphoid "minimal stress triangle": microceliotomy.

Objective: The authors devised a minimally invasive technique for cholecystectomy via microceliotomy that provides safety attainable with the open conventional approach and postoperative results comparable to laparoscopic cholecystectomy.

Summary Background Data: Laparoscopic cholecystectomy has evolved as a minimally invasive outpatient procedure. Patients can return rapidly to preoperative status with minimal postoperative morbidity and pain, and the small scar size is cosmetically desirable.

Hemostasis and healing of superficial splenic injuries using Nd:YAG laser and nonsuture techniques: preliminary report.

This study was designed to compare Nd:YAG laser to fibrin glue, electrocautery, and avitene in the management of superficial splenic injury. Six dogs were submitted to laparotomy. A #11 blade scalpel was used to sharply excise the splenic capsule inflicting four 1" x 1" superficial injuries on each spleen.

Primary closure of choledochotomy using CO2 laser: comparison with suture closure.

This study was designed to compare laser welding to suture closure of the common bile duct (CBD). A 12 mm linear choledochotomy was closed in 12 mongrel dogs using tissue welding low-energy CO2 laser. Tissue welding was accomplished at 5.