Traumatic pseudoaneurysm of the posterior auricular artery.
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Accidental Falls↗
Biomedical subjects
R O Jones
Publications and source records attributed to R O Jones.
Podiatric utilization referral patterns at an Army medical center.
Presented is the first descriptive data on a large military Podiatry Clinic supporting largely combat troops. Data consist of initial podiatric problems of soldiers and other beneficiaries of podiatric care. Demographic, physician referral patterns, and other pertinent summarized survey information of outpatient utilization at the Podiatry Clinic, Madigan Army Medical Center, Fort Lewis, Washington, are examined. Findings are based on new and initial consult referrals from the month of November 1988. The results indicated that some clinics needed inservices and further education concerning podiatric care. This study has led to the implementation of changes which have resulted in better and more timely patient care.
Adolescent↗
Use of dilute epinephrine as an aid in facial nerve monitoring.
Facial nerve monitoring during otologic and neurotologic procedures has been previously described, and its use is becoming routine. Although these procedures are done under general anesthesia, lidocaine is often used as a vehicle for epinephrine to aid hemostasis during the procedure. The routine use of lidocaine in these preparations presents the theoretical and sometimes real problem of anesthetizing the facial nerve at the start of the procedure, thereby invalidating subsequent attempts at monitoring and stimulation. We present the data from our experience with 74 patients using an epinephrine solution 1:100,000 for infiltration without any local anesthetic. We have found this procedure to be effective in maintaining hemostasis, quite safe and well tolerated, and without adverse effects on the desired monitoring of the facial nerve.
Blood Pressure↗
Rupture of low transverse cesarean scars during trial of labor.
We report eight cases of rupture of low transverse cesarean scars occurring during trials of labor. The cases occurred in five hospitals in the Denver metropolitan area during a 13-month period. The estimated incidence was 0.7% of planned trials of labor. Complications of rupture included one neonatal death, two cases of severe neonatal asphyxia, three maternal bladder lacerations, and one hysterectomy.
Adult↗
Contribution of baroreceptor reflexes to blood pressure and sympathetic responses to cholecystokinin and vasoactive intestinal peptide in anesthetized dogs.
The effects of synthetic vasoactive intestinal peptide (VIP) and cholecystokinin (CCK) on systemic blood pressure and renal nerve activity were studied before and after cervical vagotomy, and sino-aortic denervation with vagotomy in anesthetized dogs. Intravenous injection of VIP (5 micrograms/kg) in animals with an intact neuraxis produced a significant decrease in systemic blood pressure and a significant increase in renal nerve activity. These responses to VIP did not change after vagotomy and after complete denervation, VIP did not cause any change in renal nerve activity, even during hypotension. The level of hypotension after complete denervation was greater than that under other conditions. These results indicate that the cardiovascular effects of VIP are reduced by activation of the systemic baroreceptors. Intravenous injection of CCK (10 micrograms/kg) in animals with an intact neuraxis produced significant decreases in blood pressure and renal nerve activity. These responses to CCK were abolished in animals with cervical vagotomy only. However, following complete denervation of the carotid sinus and total section of the vagal nerves, CCK caused a significant increase in blood pressure and renal sympathetic nerve activity. These results indicate that the sympathetic depressor effect of CCK may be mediated by activation of the vagal afferents, and that the sympathetic pressor effect may be due to a direct action of CCK on the central nervous system. Thus, each gastrointestinal peptide may regulate the cardiovascular system through a different mechanism.
Anesthesia↗
Reflex effects on renal nerve activity and renal vascular tone during occlusion of superior mesenteric artery in anesthetized dogs.
This study was designed to evaluate the contribution of the systemic baroreceptor reflex on renal nerve activity (RNA) and renal vascular resistance (RVR) during occlusion of the superior mesenteric artery (SMAO) in anesthetized dogs. Animals were divided into two groups; RVR evaluated group and RNA measured group. For evaluation of changes in RVR, the left kidney was perfused at a constant flow with heparinized blood by using a pulsatile roller pump. Renal perfusion pressure, arterial blood pressure and heart rate were measured simultaneously. During SMAO, MAP and RVR increased significantly in animals with intact systemic baroreceptors. After combined denervation of the carotid sinus and vagal nerves, a significant enhancement of this RVR response during SMAO occurred and the level of changes in RVR were significantly greater than those in animals with an intact neuraxis. In the RNA measured group, renal sympathetic nerve activity, arterial blood pressure and heart rate were measured simultaneously before and during SMAO. During SMAO, MAP and RNA increased significantly in animals with intact systemic baroreceptors. These MAP and RNA responses to SMAO were significantly enhanced in animals with combined denervation of the carotid sinus and vagal nerves. These results indicate that SMAO evokes an increase in arterial blood pressure, renal sympathetic nerve activity and renal vascular resistance. The reflex increase in renal nerve activity and renal vascular tone during SMAO is modified and minimized by an activation of systemic baroreceptors.
Adrenergic Fibers↗
The involvement of the midbrain periaqueductal grey in the cardiovascular response to injury in the conscious and anaesthetized rat.
Cell bodies within the periaqueductal grey (PAG) of the midbrain of the propofol-anaesthetized rat were stimulated using the excitotoxin kainic acid. This resulted in a rise in arterial blood pressure and a tachycardia, together with a reduction in the sensitivity and a rightward resetting of the baroreflex. These changes mimicked the cardiovascular effect of bilateral hindlimb ischaemia in the rat. Further experiments in conscious rats indicated that electrolytic lesions in the PAG prevented the reduction in baroreflex sensitivity induced by limb ischaemia, but did not abolish the rightward resetting of the reflex or the pressor response and tachycardia when compared with sham-lesioned controls. It is postulated that the PAG, a site of importance both in the integration of the defence reaction and the processing of afferent nociceptive information, may form part of a pathway involved in the reduction of the sensitivity of the baroreflex following injury. This pathway is suggested to be separate from a second, as yet undefined, pathway mediating the baroreflex resetting and pressor responses associated with injury.
Anesthesia, Local↗
The uptake of amino acids and oxygen across the rabbit uterus in normal and postterm pregnancies.
Nineteen pregnant rabbits were studied at three different gestational ages in terms of uterine uptake of amino acids and oxygen under unstressed, steady-state conditions. The three gestational age groups were: (1) 23-25 days, (2) 26-31 days, and (3) 32-34 days (post term). The arteriovenous differences for all amino acids except glutamate and aspartate were significant in groups 1 and 2. Uterine amino acid coefficients of extraction were markedly reduced in the postterm animals (3), despite an increased uterine coefficient of extraction for oxygen. The uterine coefficients of extraction of amino acids were 2-2.5 times greater than those across the pregnant Uterus of the sheep. There was also an increased uptake of amino acid per millimoles/liter of oxygen in the rabbit compared to the sheep. Maternal arterial amino acid concentrations were not significantly different in groups 1 and 2, but the gluconeogenic amino acids serine and alanine were significantly increased in maternal arterial blood of postterm animals.
Absorption↗
Reflex responses on blood pressure and renal nerve activity to local intra-arterial injection of capsaicin in anesthetized dogs.
The present study was performed to examine effects of intra-arterial and intravenous injection of capsaicin on efferent renal sympathetic nerve activity (RNA) in pentobarbital anesthetized dogs. In animals with intact baroreceptors, intra-arterial injection of capsaicin (4 +/- 1 microgram) produced significant increases in mean blood pressure (MBP) and heart rate (HR) by +43 +/- 8 mmHg and +33 +/- 15 beats/min at 20 s after the injection, respectively. There followed a recovery toward the control so that 60 s after the intra-arterial injection changes in MBP and HR were +8 +/- 5 mmHg and +18 +/- 8 beats/min, respectively. RNA showed a biphasic response, comprising of an initial increase (+52 +/- 28% of the control at 20 s) followed by a decrease by -30 +/- 8% of the control 60 s after the injection. Following bilateral cervical vagotomy the initial increase in RNA did not differ significantly from the value of RNA in animals with intact baroreceptors. However, the later decrease in RNA reversed above the control so that 60 s after the injection change in RNA was +5 +/- 10% of the control. Complete baroreceptor denervation showed a similar response on RNA in the vagotomized animals (+49 +/- 9 and +14 +/- 10% of the control at 20 and 60 s after the injection, respectively). In contrast, intravenous injection of capsaicin (6 +/- 1 microgram/kg) resulted in significant decreases in MBP (-19 +/- 11 mmHg) and HR (-9 +/- 4 beats/min). RNA at 20 s after the injection showed a unidirectional decrease by -16 +/- 7% of the control in animals with intact baroreceptors. These responses reversed above the control after cervical vagotomy. Thus, these data indicate that activation of C-fiber afferents in skeletal muscles by intra-arterial injection of capsaicin results in renal sympathoexcitation, and that the later sympathoinhibition is mediated by combined activation of systemic baroreceptors.
Animals↗
Cardiovascular reflex function after injury.
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Animals↗
The Canadian certification examination in psychiatry. I: Historical notes.
There has been much criticism of the format and process of the certification examination in psychiatry, and some of this is based on lack of information regarding the history of the specialty certification procedures, the Royal College of Physicians and Surgeons and the Board of Examiners. In this first of three reports the history of the Royal College as the certifying organization is traced, and the relevant College structures are briefly described, including the Specialty Committee on Psychiatry which is instrumental in appointing the clinical examiners. The clinical examiners since 1965 are identified.
Canada↗
Arthur Manning Doyle 1904--1974.
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History, 20th Century↗
Differentiation in vitro of sympathetic cells from chick embryo sensory ganglia.
This study was carried out in order to determine what factors control the differentiation of certain neural crest cells in the chick embryo. Emphasis was placed on the morphologically and biochemically divergent sensory and sympathetic pathways of differentiation. Embryos were precisely stage according to Hamburger & Hamilton (1951) and it was observed that sensory ganglia with somites, explanted at stages 21-24, gave rise to cells showing formaldehyde-induced fluorescence in more than 25% of explants. These cells were identical in properties to the fluorescent cells of the sympathetic system of embryos of similar age, and appeared by 12 days in vitro. These fluorescent cells did not appear when somites and sensory ganglia explants were maintained separately. The incidence of fluorescent cells in combined explants was considerably reduced or absent when cultures were maintained for 7 days or less, or when the explants were obtained from stage 25-26 embryos. Furthermore, when neural tube was also included in the cultures, the appearance of fluorescent cells was markedly inhibited. The requirement for somitic tissue to induce fluorescent cells in combined explants can be repalced by forelimb-bud tissue. The origin of these cells and the factors that control their differentiation in vitro are discussed with reference to the neural crest origin of the sensory ganglion, and the possible conditions pertaining in vivo in this region.
Animals↗
Austin bunionectomy: postoperative MRI evaluation for avascular necrosis.
The authors used magnetic resonance imaging (MRI) to evaluate the formation rate of avascular necrosis following performance of 20 modified Austin bunionectomies. Five modified McBride bunionectomies without first metatarsal osteotomy were also performed as an MRI control. Results showed an avascular necrosis formation rate of 50%. The majority of the avascular necrosis areas were found dorsally within the cancellous bone substance of the first metatarsal head. These lesions, in all cases, did not cause any patient disability or result in any decline in the degree of patient satisfaction. The MRI positive avascular necrosis evaluations do suggest potential problem areas with the surgical technique that may be eliminated through further modification of the classic Austin bunionectomy procedure.
Adult↗
Intra-operative contamination of bone and cartilage during an Austin bunionectomy.
During an Austin bunionectomy the potential exists for the head of the metatarsal to leave the sterile field and become contaminated. The authors present a case in which this occurred, with a 20-month follow-up. Possible options for decontamination are reviewed.
Adult↗
Comparison of oblique closing base wedge osteotomies of the first metatarsal: stripping versus nonstripping of the periosteum.
The authors present a study comparing two methods of performing the oblique closing base wedge osteotomy of the first metatarsal for correction of hallux abducto valgus deformity. In one group, the periosteum was stripped from the metatarsal prior to performing the osteotomy, and in the other group, the osteotomy was performed through the periosteum. Sixty-five osteotomies are included in the study. This article discusses the closing base wedge osteotomy, fracture healing and the role of the periosteum, the blood supply to the first metatarsal, and the effects of periosteal stripping. Also included is a presentation of the surgical technique used, a statistical review of the procedures performed, a critical discussion summarizing the results, and a discussion of the postoperative complications encountered.
Female↗