The Reptilian Baroreceptor and Its Role in Cardiovascular Control

Anatomical evidence for the existence of a depressor nerve inreptiles was first reported 100 years ago. Electrical stimulationof the central end of the cut nerve, however, did not producean unequivocal fall in heart rate and blood pressure, so itwas thought not to function as a depressor nerve. This remainedthe state of knowledge for fifty years when Marco Fedele performeda superb anatomical and physiological study of the depressornerves of turtles and lizards. He demonstrated that there weretwo depressor nerves from each vagus; the superior nerve originatedfrom the jugular ganglion or superior laryngeal nerve in turtlesand from the superior laryngeal nerve or vagus in lizards; theinferior nerve originated from the nodose ganglion or slightlycaudad of this ganglion. The nerves were shown to terminatein the proximal truncus arteriosus. Unlike the earlier workers,Fedele obtained a clear depressor effect on stimulating thedepressor nerves. In more recent times baroreflexes have been demonstrated inresponse to hemorrhage and body tilting in reptiles, with snakesreceiving particular attention. The evidence indicates thataquatic snakes are less effective at maintaining blood pressurethan terrestrial and arboreal forms. The sensitivity (gain)of the baroreceptor-heart rate reflex, when it is expressedas a percentage change in heart rate per unit pressure change,is approximately the same in reptiles, amphibians, and mammals.In addition, the ultrastructural appearance of the baroreceptorsof lizards is similar to that of mammals. A quantitative assessmentof the ability of reptiles to correct disturbances in bloodpressure has not yet been made, but techniques for obtainingthis information are now available.     

喉上神经阻滞联合利多卡因雾化吸入在支气管镜诊疗中的应用

摘要 目的：比较喉上神经阻滞联合利多卡因雾化吸入法与利多卡因含漱法用于支气管镜诊疗的治疗效果及安全性。方法：选取新疆医科大学第三临床医学院首次行气管镜诊疗的患者120例，随机分为4组。利多卡因含漱组：2%盐酸利多卡因注射液喉部含漱；利多卡因雾化吸入组：2%利多卡因注射液雾化吸入；喉上神经阻滞组：B超定位下以1%利多卡因阻滞双侧喉上神经内支。联合组：联合使用喉上神经内支阻滞与利多卡因雾化吸入。记录各组在诊疗中咳嗽、憋喘、体动次数及操作期间患者血压、心率、血氧饱和度等情况，以及诊疗后疼痛视觉模拟评分（VAS评分）。结果：利多卡因含漱组呛咳、憋喘发生率最高，显著高于其余各组（P＜0.01）；联合组呛咳、憋喘发生率最低，显著低于其余各组（P＜0.05）。利多卡因含漱组患者血压、心率在支气管镜进入声门时及气管内诊疗时显著高于各组（P＜0.01）；联合组患者的平均动脉压及心率在支气管镜进入声门时低于（P＜0.05）其余两组。各组SpO₂均高于90%，其中利多卡因含漱组患者最低（P＜0.01），联合组最高（P＜0.05）。各组疼痛VAS评分多低于3分，但在各组之间均有差异（P＜0.05），其中联合组最低（P＜0.05）。结论：喉上神经内支阻滞联合利多卡因雾化吸入用于支气管镜诊疗可以有效地抑制气管应激反应，减少疼痛刺激，有利于维持诊疗期间的血流动力学稳定，其安全性和有效性优于利多卡因含漱法及单独采用利多卡因雾化吸入或喉上神经阻滞法。支气管镜诊疗过程中患者多为轻度疼痛，咽喉部不适引起的呛咳、憋喘才是患者难以耐受的原因。     

Spontaneous Rupture of Hepatocellular Carcinoma

Forty-two cases of ruptured hepatoma with intra-abdominal haemorrhage were seen over a period of eight years in the professorial surgical unit at the Queen Mary Hospital, Hong Kong. In all, 207 cases of liver cancer were seen during this period, giving an incidence of rupture of 14·5%. There were 37 men and five women. The clinical features were the sudden onset of pain with shock and the presence of blood in the peritoneal cavity. The diagnosis was made before operation on suspicion and by a process of elimination. In cases of doubt paracentesis abdominis was performed to determine whether there was blood in the peritoneal cavity. Treatment was directed to control of haemorrhage and resection.The prognosis, although extremely poor, is no worse than the hepatocellular carcinoma that has not ruptured. There was one long-term survivor—a patient who had undergone an extensive resection. The man was alive and well after more than five years.     

CANCER DETECTION CENTERS—The Experience to Date in California

Cancer “detection centers” (that is, centers for the examination of presumably well or asymptomatic persons) have been tried out in four different California communities during the last three years. In all instances—as in most other such centers throughout the United States—they have not been successful in restricting examination to well persons.The detection centers in California may therefore be described more accurately as “cancer examination and detection clinics.”Three of the four centers have been closed owing to the small yield of cancer cases discovered, plus the fact that the cost of operation exceeded the total available funds of the local branch of the Cancer Society. In addition, it was extremely difficult to obtain and maintain competence on the part of the professional staff in such centers.A more practical approach to the problem of earlier tumor detection would appear to be emphasis on making “every physician''s office a detection center,” and stressing the annual examination of persons over 40 years of age for tumors in the five common accessible sites. These are the tumors most readily curable today.     

FATIGUE FRACTURES IN TRACK ATHLETES

Pain in a foot or in the lower leg, not related to specific injury, in a track athlete who does a great deal of running, is the first symptom of fatigue fracture. X-ray films taken at the time pain begins may show no abnormality. Films taken a month or more later may show formation of callus, and perhaps a fracture line, at the point of pain.Usually no treatment beyond cessation of running for two months or more is needed.Since the incidence is highest in middle-distance runners who train intensively—quartermilers in particular—and may be related to the hardness of the running track, limiting running to alternate days and doing part of it on grass may help in prevention.     

SALIVARY GLAND TUMORS

In a review of a series of 248 salivary gland tumors, seen over a 28-year period, all pathologic material was brought up to date by reclassification according to more recent criteria and nomenclature. In parotid tumors, a probable lowered recurrence rate and a definite decrease in incidence of permanent facial nerve paralysis was found in the more recent cases in which the “Y” incision was used, with identification of the seventh nerve as it leaves the stylomastoid foramen. The five-year recurrence rate for primary mixed tumor was 8.3 per cent, and in recurrent cases it was found to be 18.1 per cent.Of 44 patients with malignant salivary gland tumors in all sites who were observed for five years or more, 32 or 72.7 per cent survived five years.     

Is evolutionary history repeatedly rewritten in light of new fossil discoveries?

Mass media and popular science journals commonly report that new fossil discoveries have ‘rewritten evolutionary history’. Is this merely journalistic hyperbole or is our sampling of systematic diversity so limited that attempts to derive evolutionary history from these datasets are premature? We use two exemplars—catarrhine primates (Old World monkeys and apes) and non-avian dinosaurs—to investigate how the maturity of datasets can be assessed. Both groups have been intensively studied over the past 200 years and so should represent pinnacles in our knowledge of vertebrate systematic diversity. We test the maturity of these datasets by assessing the completeness of their fossil records, their susceptibility to changes in macroevolutionary hypotheses and the balance of their phylogenies through study time. Catarrhines have shown prolonged stability, with discoveries of new species being evenly distributed across the phylogeny, and thus have had little impact on our understanding of their fossil record, diversification and evolution. The reverse is true for dinosaurs, where the addition of new species has been non-random and, consequentially, their fossil record, tree shape and our understanding of their diversification is rapidly changing. The conclusions derived from these analyses are relevant more generally: the maturity of systematic datasets can and should be assessed before they are exploited to derive grand macroevolutionary hypotheses.     

Irradiation influences the expression of substance P and enkephalin in the rat larynx

The effects of radiotherapy on neuropeptide expression in the rat larynx were studied. Irradiation was given for five days, 6 or 8 Gray daily. Ten days after the end of irradiation, the larynx, the laryngeal nerves and different ganglia related to the larynx were dissected out from irradiated and control animals and processed for neuropeptide immunohistochemistry. There was an increased immunolabelling for two of the neuropeptides tested, substance P and enkephalin, in the innervation of the subglottic glands and in the acetylcholinesterase-positive ganglionic cells of the local ganglia. These cells were interpreted as representing postganglionic parasympathetic ganglionic cells. The changes seen in the subglottic glands were interpreted as most likely being related to the changing pattern of staining seen in the local ganglia. No changes in substance P-and enkephalin expression were observed in other laryngeal structures, the nodose ganglia, superior cervical ganglia or laryngeal nerve paraganglia. Thus, in certain respects neuropeptide expression in the larynx is modulated by radiotherapy. Since neuropeptides have both neurotransmitter and/or neuromodulator effects in airway tissue and since they show effects as growth factors, the occurrence of this plasticity in neuropeptide expression should be taken into consideration in future studies examining the effects of irradiation on normal/diseased airway tissues.     

Neuropeptides as central integrators of autonomic nerve activity: effects of TRH, SRIF, VIP and bombesin on gastric and adrenal nerves

The nerve activity of the gastric ramus of the splanchnic (sympathetic) nerve, gastric ramus of the vagus, adrenal ramus of the splanchnic nerve and the superior laryngeal nerve (laryngeal ramus of vagus) were assessed before and after i.c.v. injection of neuropeptides in the rat. TRH stimulated the vagal branch but attenuated the sympathetic outflow to the stomach. In contrast, the sympathetic outflow to the adrenal was enhanced by TRH. SRIF suppressed the activity of all the nerves studied. VIP did not affect the sympathetic outflow to the stomach while suppressing the gastric branch of the vagus. The adrenal sympathetic branch as well as the superior laryngeal nerve was stimulated by VIP. Bombesin suppressed both vagal and sympathetic outflow to the stomach but markedly stimulated the laryngeal branch of the vagus. The adrenal sympathetic nerve was either stimulated or attenuated slightly by bombesin. These results indicate that centrally administered neuropeptides produce reactions specific for each nerve.     

A TEST FOR EVALUATING PEDAL GANGRENOUS LESIONS—Observation of Elevation Reactive Hyperemia as a Gauge of Blood Supply

Estimating the development of collateral circulation in peripheral vascular diseases is simplified by the use of an easy test—which can be done in an office—in which reactive hyperemia is observed in an extremity as it is gradually lowered after a period of elevation.The lower limits of filling pressures necessary to allow spontaneous healing of necrotic lesions under the conditions described seem to be in the range 35 cm. above the heart. Similarly the lower limit for the successful performance of amputations at the level of the forefoot or toes seems to be about 45 cm.As a result of over a thousand observations in a period of over five years, it is believed that the test provides in a few minutes a visual and reproducible picture of the filling pressures in the distal portions of the extremity which is useful in the determination of prognosis and the selection of treatment of gangrenous lesions of the foot.     

Functional differentiation of superior laryngeal nerve afferents in cats

Electrophysiological characteristics of superior laryngeal nerve fibers and reflex responses in respiratory motor nerves and the recurrent nerve were investigated in acute experiments on cats under superficial pentobarbital anesthesia. Analysis of the compound action potential in the superior laryngeal nerve revealed three distinct groups of afferent fibers subserving different functions: group A, responsible for proprioceptive mechanisms of coordination of activity of the laryngeal muscles; group A(₃), responsible for feedback mechanisms between the receptor apparatus of the mucous membrane and muscles of the larynx and bulbar respiratory neurons, and group A, responsible for the development of protective respiratory reflexes.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 16, No. 6, pp. 777–783, November–December, 1984.     

Five-year winter chemoprophylaxis for chronic bronchitis

Seventy-nine patients with chronic bronchitis were randomly allotted to four treatment regimens—placebo throughout the winter months for five years; tetracycline for the first two winters and placebo for the next three; placebo for the first two winters and tetracycline for the next three; and tetracycline for five winters. In addition all groups recevied a five-day course of tetracycline for any acute exacerbation. There was a significant reduction in the number of exacerbations among the more susceptible patients—that is, those who suffered more than one exacerbation each winter. Though the average decline in F.E.V.₁ over the five-year period was less in the treated groups this was not statistically significant. There was no significant difference between the groups in respect of lung volumes, diffusing capacity, and blood gases.     

Randomised controlled trial of laparoscopic versus open mesh repair for inguinal hernia: outcome and cost

Objective: To compare tension-free open mesh hernioplasty under local anaesthetic with transabdominal preperitoneal laparoscopic hernia repair under general anaesthetic. Design: A randomised controlled trial of 403 patients with inguinal hernias. Setting: Two acute general hospitals in London between May 1995 and December 1996. Subjects: 400 patients with a diagnosis of groin hernia, 200 in each group. Main outcome measures: Time until discharge, postoperative pain, and complications; patients’ perceived health (SF-36), duration of convalescence, and patients’ satisfaction with surgery; and health service costs. Results: More patients in the open group (96%) than in the laparoscopic group (89%) were discharged on the same day as the operation (χ²=6.7; 1 df; P=0.01). Although pain scores were lower in the open group while the effect of the local anaesthetic persisted (proportional odds ratio at 2 hours 3.5 (2.3 to 5.1)), scores after open repair were significantly higher for each day of the first week (0.5 (0.3 to 0.7) on day 7) and during the second week (0.7 (0.5 to 0.9)). At 1 month there was a greater improvement (or less deterioration) in mean SF-36 scores over baseline in the laparoscopic group compared with the open group on seven of eight dimensions, reaching significance on five. For every activity considered the median time until return to normal was significantly shorter for the laparoscopic group. Patients randomised to laparoscopic repair were more satisfied with surgery at 1 month and 3 months after surgery. The mean cost per patient of laparoscopic repair was £335 (95% confidence interval £228 to £441) more than the cost of open repair. Conclusion: This study confirms that laparoscopic hernia repair has considerable short term clinical advantages after discharge compared with open mesh hernioplasty, although it was more expensive.

Key messages

• In the 4 hours after surgery laparoscopic hernia repair with general anaesthesia causes more pain than open repair with local anaesthesia (mainly because of the anaesthesia used) and necessitates longer stay in hospital. Laparoscopic hernia repair, however, causes less pain than open hernia repair during the first 2 weeks after discharge
• Laparoscopic hernia repair results in fewer episodes of wound infection, persistent local pain, genital swelling, numbness, and constipation than open repair. Urinary disturbances are more common after laparoscopic than after open repair
• Patients’ perception of health 1 month after the operation (assessed with the SF-36) and satisfaction with treatment is superior for laparoscopic patients who also have a shorter period of convalescence after surgery
• The health service cost of day case laparoscopic repair is £335 more than the cost of open mesh hernioplasty performed on a day case basis

     

INFLUENZA VACCINE,ASIAN STRAIN—Reactions Following Its Use in Adults

A study of reactions following influenza vaccine inoculation of 327 employees of Peralta Hospital, 55 men and 272 women, showed a very low value for significant or severe reactions. The reaction rate as observed with the present monovalent vaccine containing 200 CCA units of Asian strain, Type A influenza virus, was considerably lower than that reported with previous polyvalent vaccines containing up to 1,400 or 1,500 CCA units of total virus content.The absenteeism rate was 1.1 per cent for women, nil for men.The incidence of reactions was much greater in women than in men. Local reactions such as pain, swelling, or redness at the site of injection occurred in 29.1 per cent of men and 35.7 per cent of women. The incidence of systemic reactions—fever, aching, chilliness, headache, nausea and vomiting—was 3.6 per cent in men and 8.8 per cent in women. About 9 per cent of men and 30 per cent of women had both local and systemic reaction. Some 58 per cent of men and 25 per cent of women had no reaction.The greater majority of reactions appeared within five hours after inoculation with influenza vaccine.In adults the prevention of anaphylactic reactions due to the small amount of egg protein in influenza vaccine, can be accomplished by screening for history of hypersensitivity to egg, chicken or chicken feather. In questionable cases, intradermal testing can be done.The reaction rate observed in this study for the present influenza vaccine was so low that it ought not deter immunization.     

Analysis of the analgesic effects of tricyclic antidepressants on neuropathic pain,diabetic neuropathic pain,and fibromyalgia in rat models

ObjectiveTo investigate the analgesic effect of amitriptyline on neuropathic pain model rats, diabetic neuropathic pain model rats and fibromyalgia model rats.MethodsThe healthy male Sprague wrote – Dawley (SD) rats were taken as the research object, and they were randomly divided into model group (group A), beside the sciatic nerve and injection of 5 mm amitriptyline group (group B), beside the sciatic nerve and injection of 10 mm amitriptyline group (group C), beside the sciatic nerve and injection of 15 mm amitriptyline group (group D), intraperitoneal injection of amitriptyline group (group E). Pain induced by selective injury of sciatic nerve branches in rats, pain induced by chronic compression of sciatic nerve, diabetic neuropathic pain and fibromyalgia were conducted to determine the pain threshold of mechanical stimulation in rats after drug administration.ResultsThe pain threshold of mechanical stimulation in the local amitriptyline group (group B, C, D) was significantly higher than that in the group A and group E at each time point after drug treatment, and the pain threshold of mechanical stimulation gradually increased with the increase of concentration. There was no statistically significant difference in mechanical stimulation pain threshold between group A and group E at each time point after drug treatment.ConclusionPara-sciatic injection of amitriptyline at different concentrations has analgesic effects on neuropathic pain, diabetic neuropathic pain and fibromyalgia in rat models, and amitriptyline directly ACTS on the local sciatic nerve.     

Neural Photoreception in a Lamellibranch Mollusc

The pallial nerves of Spisula solidissima each contain a single afferent nerve fiber which responds directly to illumination of the nerve, and apparently mediates the "shadow" response of siphon retraction. These units show constant-frequency spontaneous activity in the dark; illumination abruptly inhibits this discharge, and cessation of the light stimulus then evokes a prolonged burst of impulses at high frequency (the off-response). Impulses are initiated at a point near the visceral ganglion, and propagated unidirectionally toward it. Stimulation with monochromatic light has revealed that more than one photoreceptor pigment is involved, since the discharge patterns evoked are wavelength-specific. Inhibition is relatively prominent at short wavelengths, excitation at long wavelengths. Following selective adaptation with blue light, "on" responses can be produced with red stimuli, demonstrating the unmasking of an excitatory event which takes place during illumination. The two photoreceptor pigments may be segregated in two or more cells presynaptic to the recorded unit, or,—more likely—may both be contained in the same cell. The spectral sensitivity function for inhibition shows a single maximum at 540 mµ, and is probably dependent upon a carotenoid pigment. No photoreceptor function has been demonstrated for a hemoprotein, apparently identical with cytochrome h, which occurs in high concentration in Spisula nerve.     

Lipid Droplets and Peroxisomes: Key Players in Cellular Lipid Homeostasis or A Matter of Fat—Store ’em Up or Burn ’em Down

Lipid droplets (LDs) and peroxisomes are central players in cellular lipid homeostasis: some of their main functions are to control the metabolic flux and availability of fatty acids (LDs and peroxisomes) as well as of sterols (LDs). Both fatty acids and sterols serve multiple functions in the cell—as membrane stabilizers affecting membrane fluidity, as crucial structural elements of membrane-forming phospholipids and sphingolipids, as protein modifiers and signaling molecules, and last but not least, as a rich carbon and energy source. In addition, peroxisomes harbor enzymes of the malic acid shunt, which is indispensable to regenerate oxaloacetate for gluconeogenesis, thus allowing yeast cells to generate sugars from fatty acids or nonfermentable carbon sources. Therefore, failure of LD and peroxisome biogenesis and function are likely to lead to deregulated lipid fluxes and disrupted energy homeostasis with detrimental consequences for the cell. These pathological consequences of LD and peroxisome failure have indeed sparked great biomedical interest in understanding the biogenesis of these organelles, their functional roles in lipid homeostasis, interaction with cellular metabolism and other organelles, as well as their regulation, turnover, and inheritance. These questions are particularly burning in view of the pandemic development of lipid-associated disorders worldwide.WORK for the past five decades on the yeast Saccharomyces cerevisiae has contributed fundamental insight into peroxisome biogenesis and function that is also relevant for mammalian cells. While LD research in yeast is still in its infancy and looks back to a much shorter history—the previous edition of YeastBook did not even mention LDs as an “organelle”—combined biochemical, cell biological, lipidomic, and proteomic studies in recent years have already contributed significant insight into LD biogenesis and function.     

PARTURIENT PERINEORRHAPHY

In the light of improved means of combating infection, better and safer anesthesia, the ready availability of blood transfusion, and less traumatic delivery, reasons formerly advanced in opposition to operations at the time of parturition for repair of preexisting lesions of the pelvic floor are now less formidable than they were in the past.Such operations now can be carried out quickly and safely with considerable benefit in terms of immediate comfort and well-being of the patient, prevention of later development of more serious lesions, and savings in cost of hospitalization.In a series of more than 300 patients so operated upon—the technique used is described herein—none died, and in a review of the records many advantages of operation immediately after delivery, as compared with long delay of needed repair, were noted.     

INDICATIONS FOR LUMBOSACRAL FUSION

In cases in which operation is indicated, the author advocates routine fusion of the lumbosacral joint in all cases of protrusion of the 5th lumbar disc, providing the spine above that level is considered essentially normal.He would do spinal fusion in all cases—provided operation were indicated—in which the primary complaint was that of low back pain and in which sciatic pain was absent or minimal. In such cases, the fusion area should extend as far as necessary to include the portion of the spine involved in pathologic change. Only in exceptional cases would spinal fusion be done in patients more than 50 years of age.With the exceptions noted, all patients requiring reoperation should have the benefits of lumbosacral fusion.     

Laryngeal C-fiber afferents are not involved in the apneic response to laryngeal wood smoke in anesthetized rats

Laryngeal exposure to wood smoke in rats evokes a reflex apnea which is mediated through superior laryngeal afferents (J. Appl. Physiol. 83: 723-730, 1997). To study the role of laryngeal C-fiber afferents in eliciting this response, capsaicin aerosol (0.05 - 0.2 microg/ml) and 5 ml of wood smoke were delivered separately into a functionally isolated larynx of anesthetized Sprague-Dawley rats at a constant flow rate of 1.4 ml/s, while animals breathed spontaneously. Studies were repeated after either an intravenous injection of ruthenium red (2 mg/kg; n = 8), a perineural capsaicin treatment (200 microg/ml for 5 min; n = 8) of the superior laryngeal nerves, or a perineural sham treatment (n = 8); Ruthenium red inhibits the stimulation of afferent C-fiber nerve endings by capsaicin, whereas perineural capsaicin treatment selective blocks the conduction of C-fiber afferents. Either ruthenium red or perineural capsaicin treatment abolished the apneic response to laryngeal capsaicin, but did not significantly affect the apneic response to laryngeal wood smoke. Furthermore, the apneic responses to both types of irritants were not significantly altered by perineural sham treatment, yet were completely eliminated by a subsequent denervation of superior laryngeal nerves. Our results suggest that superior laryngeal C-fiber afferents are not involved in eliciting the reflex apneic response to laryngeal wood smoke in anesthetized rats. It is speculated that this response may result mainly from the stimulation of myelinated afferents, possibly laryngeal irritant receptors.