Description of Ovariectomy Protocol in Mice.

Estrogen and ovarian function decline are relevant characteristics of menopause period. Numerous physiological, metabolic and immunological alterations in the female body occur in the menopause period and some of these changes remain uncertain. The animal model that mimics menopause phase is an important approach to better comprehend the biological process involved in this period of women life. Ovariectomy is a procedure where ovaries are surgically excised and have been a valuable tool for understanding estrogen deficiency through animal experiments. Despite the diversity of ovariectomy protocols, the aim of this chapter is to provide a comprehensive guideline in performing ovariectomy in mice. Furthermore, isoflurane anesthesia system, postoperative care and surgery success evaluation will be described. We highlight that all procedures must be carried out by a qualified and trained professional, respecting ethical and safety principles.

Antiemetic efficacy of combined aprepitant and dexamethasone in patients at high-risk of postoperative nausea and vomiting from epidural fentanyl analgesia.

BACKGROUND: Postoperative opioid analgesia increases the incidence of postoperative nausea and vomiting (PONV). We investigated whether a combination of the neurokinin-1 antagonist aprepitant and dexamethasone decreases PONV incidence compared with dexamethasone alone in high-risk patients receiving continuous epidural fentanyl. METHODS: Sixty nonsmoking female patients scheduled for elective knee osteoarthritis surgery were randomly allocated to receive oral aprepitant 80 mg (aprepitant+dexamethasone group, N.=30) 2 h before anesthesia induction or no oral aprepitant (dexamethasone group, N.=30). All patients received intravenous dexamethasone 8 mg immediately before anesthesia induction. Anesthesia was maintained with remifentanil and sevoflurane. Continuous infusion of epidural analgesia, including fentanyl, was provided during and after surgery. We assessed complete response (no PONV and no rescue antiemetic use), incidence of nausea and vomiting, nausea severity scale, vomiting frequency, rescue antiemetic use, and postoperative pain at 2 and 24 h after surgery. RESULTS: The cumulative incidence of vomiting at 24 h was 3% in the aprepitant+dexamethasone group and 27% in the dexamethasone group (P=0.011). The incidence and frequency of vomiting in the late postoperative period was also significantly lower in the aprepitant+dexamethasone group than in the dexamethasone group. However, there were no significant group differences in the proportion of patients who experienced a complete response, the incidence and severity of nausea, and rescue antiemetic use at 24 h. CONCLUSION: The combination of aprepitant and dexamethasone was more effective in preventing postoperative vomiting compared with dexamethasone alone in patients at high-risk of PONV from continuous epidural fentanyl analgesia.

[Severe lightning pain during spinal anesthesia in a patient with diabetic neuropathy].

A 71-year-old woman with diabetic neuropathy who had undergone amputation of the right lower leg for diabetic gangrene 4 years previously, experienced severe lightning pain in both legs during spinal anesthesia. She was scheduled for skin grafting for a burn ulcer on her left foot. Her preoperative physical examination revealed hypesthesia in both legs due to diabetic neuropathy. Spinal anesthesia was performed with a combined spinal-epidural needle at the L 4-5 interspace using 2.0 ml of 0.3% hyperbaric dibucaine in the left lateral position. The region of hypesthesia was spread below Th 4. Ten minutes later, she complained of severe lightning pain in both legs and midazolam 1 mg was administered intravenously against agitation. The severe lightning pain diminished after the administration of pentazocine 7.5 mg intravenously in the recovery room. There was no worsening of neurological findings 5 hours later when the effect of spinal anesthesia disappeared. This clinical picture seems to be different from that of reported cases of phantom limb pain during spinal anesthesia in which severe lightning pain occurred in both legs. This case suggests that patients with diabetic neuropathy might develop severe lightning pain during spinal anesthesia using dibucaine.

[Effects of pentobarbital on coronary and cerebral circulation and metabolism in dogs subjected to hemorrhage].

Mongrel dogs were divided into a neuroleptanesthesia group (n = 10) and a pentobarbital group (neuroleptanesthesia plus pentobarbital; n = 10). The dogs were subjected to stepwise hemorrhage increasing from 30 to 40 and 50 ml.kg-1. In the neuroleptanesthesia group, mean arterial pressure, and cerebral and coronary blood flow decreased. Furthermore the oxygen and hydrogen ion balance in both the brain and the myocardium was aggravated, even at 30 ml.kg-1 of hemorrhage. Compared to the neuroleptanesthesia group, mean arterial pressure, and cerebral and coronary blood flow showed a greater decrease, cerebral oxygen consumption was lower, and the brain and myocardial metabolism worsened similarly at equivalent hemorrhage in the pentobarbital group. These results suggest that pentobarbital in combination with neuroleptanesthesia reduces cerebral oxygen consumption, but does not improve cerebral metabolism in the state of acute hemorrhage due to simultaneous induction of severe circulatory depression.

[Effects of deep halothane and isoflurane anesthesia on cerebral as well as coronary metabolism].

Mongrel dogs were subjected to halothane or isoflurane to examine the relationship between systolic blood pressure and cerebral as well as myocardial metabolism. The oxygen and hydrogen ion balances in the brain were not disturbed in either group to the systolic blood pressure level of 70 mmHg and were well maintained in the isoflurane group below this level. The myocardial oxygen balance was not aggravated in either group, whereas, the myocardial hydrogen ion balance was disturbed in the halothane group at the systolic blood pressure level between 70 mmHg and 50 mmHg though it was preserved in the isoflurane group. These findings demonstrate that the systolic blood pressure not disturbing oxygen and hydrogen ion balances in the brain and myocardium is 70 mmHg during halothane or isoflurane anesthesia, while isoflurane anesthesia becomes advantageous at the systolic blood pressures below this level. While the myocardial metabolism is less affected by lowering of blood pressures than the cerebral metabolism, it seems important to secure cardiac functions to maintain metabolism in both organs.

In vitro mutagenesis by incorporation of N4-aminodeoxycytidine 5'-triphosphate.

We have investigated the possibility of introducing a new way to carry out in vitro mutagenesis. N4-Aminodeoxycytidine 5'-triphosphate was used in the Klenow enzyme-catalyzed chain elongation of a primer oligonucleotide hybridized to a lacZ alpha region of M13mp2 viral single strand DNA, and the possibility of inducing an efficient, randomly distributed point mutations into this particular genomic region was explored. On transfection of the resulting DNA into E. coli, mutant phages emerged at frequencies up to 1%. Analysis of the DNA sequences of the mutants has shown that single transitions, either A to G or G to A, were induced in a random fashion, thus providing data to show the possibility of using this method for production of mutant proteins having various single amino-acid changes in a defined domain.