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PubMed2005

The completely opacified frontal or sphenoid sinus: a marker of more severe disease in chronic rhinosinusitis?

OBJECTIVE: Determine whether complete opacification of the sphenoid or frontal sinus is associated with increased clinical severity of chronic rhinosinusitis (CRS). METHODS: Adult patients undergoing evaluation for CRS prospectively completed the rhinosinusitis symptom inventory (RSI) and underwent computed tomography of the paranasal sinuses. A cohort with at least one completely opacified frontal sinus was identified. To each patient in this opacified cohort, a control patient without complete frontal sinus opacification was matched with corresponding Lund score. Symptom scores for headache, facial pressure, RSI symptom domains, and medical resource consumption were statistically compared. Similar analysis was conducted for patients with complete sphenoid sinus opacification. RESULTS: Fifty-four patients with at least one completely opacified frontal sinus were matched for Lund score to the control group (mean Lund score 17.1). There was no statistically significant difference in headache (2.1 vs. 2.8) or pressure scores (2.0 vs. 2.3) or in the RSI symptom domains between those patients with completely opacified frontal sinuses and controls, respectively. Although completely opacified patients received more antibiotic treatment and missed more workdays, only the increased numbers of physicians visits (4.0 vs. 2.1, P = .02) was significant. Thirty-four of 35 completely opacified sphenoid patients were matched to control patients (mean Lund score 16.7). Again, differences in symptom scores for headache (2.5 vs. 2.5), facial pressure (2.3 vs. 2.3), and RSI symptom domains were not statistically significant. Increased use of antibiotics (9.6 vs. 3.9, P = .036) and physician visits (5.8 vs. 1.8, P = .024) for sphenoid opacification patients was statistically significant. CONCLUSIONS: Patients with a completely opacified sphenoid or frontal sinus do not necessarily manifest more severe clinical symptoms of CRS. Thus, a higher radiographic stage should not be automatically assigned to patients with a completely opacified sphenoid of frontal sinus in CRS.

Adult↗
PubMedDate not supplied

A large frontonasal bone flap for sinus surgery in the horse.

A large frontonasal bone flap was created to treat diseases of the paranasal sinuses in 14 horses. The bone flap was made as wide as possible within the confines of the nasolacrimal duct so the floor of the frontal sinus and the dorsal and ventral conchae could be opened. These openings exposed the nasal passages, maxillary sinuses, and ventral conchal sinus thereby facilitating removal of diffuse and localized lesions from these sites. Diseases treated were ethmoid hematomas (4 horses), sinus cysts (5 horses), cryptococcal granuloma, osteoma, hemangiosarcoma, pus in the ventral conchal sinus, and periapical infection of a second molar. Four horses were euthanatized during or after surgery, one because of postsurgical pleuritis and pneumonia (horse with osteoma) and three because of their primary problems (cryptococcal granuloma, hemangiosarcoma, pus in the ventral conchal sinus). Skin suture abscesses that responded to treatment developed in four horses. Ten horses returned to their intended uses, the sinus flaps healed without blemish, and the original problems did not recur. The frontonasal flap technique provided greater access to all paranasal sinuses than methods described previously.

Animals↗
PubMedDate not supplied

Osteoplastic flap versus modified endoscopic Lothrop procedure in patients with frontal sinus disease.

The aim of the present study was to review the clinical results of osteoplastic flap procedure with abdominal fat obliteration and modified endoscopic Lothrop procedure. Charts of patients with frontal sinus disease who underwent osteoplastic flap procedure with abdominal fat obliteration or modified endoscopic Lothrop procedure were retrospectively reviewed. Forty-three patients with frontal sinus disease underwent osteoplastic flap procedure with abdominal fat obliteration. Frontal sinus disease was chronic sinusitis in 21, mucocele in 18, and papilloma in four. None of the patients had recurrence within 3 to 12 years follow-up period. Six patients had decreased forehead sensation, one had a CSF leak, and one had loss of the fat graft. Fifteen patients with chronic frontal sinusitis underwent modified endoscopic Lothrop procedure. The follow-up period ranged from 0.5 to 2.5 years. Two patients had recurrence of disease 2 and 6 months after surgery and required osteoplastic flap. In patients with chronic frontal sinusitis, both procedures achieved good relief of symptoms; however, follow-up time of modified endoscopic Lothrop procedure was smaller than that of osteoplastic flap procedure. In conclusion, osteoplastic flap procedure with abdominal fat obliteration provides successful treatment in patients with frontal chronic sinusitis, mucocele, or papilloma. Modified endoscopic Lothrop procedure achieves the relief of symptoms in patients with chronic frontal sinusitis. With the future availability of long term follow-up results, modified endoscopic Lothrop procedure may reduce the number of osteoplastic flap procedures in patients with chronic frontal sinusitis.

Adult↗
PubMed2004

The pathogenicity and antibiotic resistance of coagulase-negative Staphylococci isolated from the maxillary and ethmoid sinuses.

AIM OF THE STUDY: To investigate the pathogenicity and antibiotic resistance of coagulase-negative staphylococci (CNS) isolated from the maxillary and ethmoid sinuses of patients undergoing endoscopic sinus surgery for chronic sinusitis. PATIENTS AND METHODS: Ninety-three patients (63 males, 30 females) aged between 19 - 68 years, who had undergone functional endoscopic sinus surgery (FESS) for chronic sinusitis, were included in the study. Nasal mucosa, skin and adjacent structures were cleansed with povidone-iodine solution before surgery to prevent a probable contamination. In all patients, nasal swabs were taken before and after the application of povidone-iodine solution. Colonies isolated and identified as Staphylococci in cultures were further investigated for pathogenicity and antibiotic susceptibility. Slime test was used to determine the pathogenicity of CNS. The relationship between antibiotic resistance of pathogenic and non-pathogenic CNS was compared by chi2 analysis. RESULTS: While bacterial growth rate was 62.3% in nasal swab cultures taken before the application of povidone-iodine solution, it decreased to 12.9% after the application of solution. Microorganisms were isolated in 95.6% of cultures taken from maxillary sinuses and in 91.3% of cultures obtained from ethmoid sinuses during the FESS. The most frequently isolated microorganism in each of the sinuses was CNS. Slime test was carried out in 30 CNS isolated. Twelve of these were slime positive and 18 were slime negative. While 83.3% of CNS isolated was resistant to penicilin, all of CNS were sensitive to vancomycin and teikoplanine. The difference between slime positive and slime negative CNS for gentamicin and ciprofloxacin resistance was statistically significant (p<0.05). CONCLUSION: We consider that the pathogenicity tests like slime production and antimicrobial susceptibilities of CNS frequently isolated from the patients with chronic sinusitis should be investigated and also these microorganisms should be kept in mind in the selection of empiric treatment.

Adult↗
PubMedDate not supplied

Effectiveness of pseudoephedrine plus acetaminophen for treatment of symptoms attributed to the paranasal sinuses associated with the common cold.

BACKGROUND: Little data exist on the cause and treatment of subfacial pain and pressure and other discomfort attributed to the paranasal sinuses that develop early during the course of the common cold. The purpose of this study was to determine the efficacy of the combination of pseudoephedrine hydrochloride with acetaminophen for the treatment of early symptoms during colds, which are attributed by the patient to the sinuses. METHODS: Four hundred thirty subjects (216, pseudoephedrine and acetaminophen recipients; 214, placebo recipients) with cold symptoms of 48 hours or less who reported overall "sinus" symptoms of at least moderate severity were enrolled in this randomized double-blind placebo-controlled 2-dose study. Self-reported symptoms were scored (0 to 4, absent to severe) before and at 2 hours after the first and second doses. The 2 primary were measured 2 hours after the second dose were the overall sinus symptom assessment and a weighted composite assessment of sinus pressure, pain, and congestion (sinus symptoms). RESULTS: Compared with baseline, 2 hours after the second dose, the mean +/- SEM overall sinus symptom assessment score had decreased by 1.30 +/- 0. 06 in the pseudoephedrine and acetaminophen-treated subjects compared with 0.93 +/- 0.06 in the placebo-treated subjects (P< or = .029). The mean +/- SEM weighted average of sinus symptoms 2 hours after the second dose of study medication had decreased by 1.14 +/- 0.06 in the pseudoephedrine and acetaminophen-treated subjects compared with 0.84 +/- 0.06 in the placebo-treated subjects (P< or = .029). Reductions in similar magnitude were also observed for each of the individual sinus symptoms, and headache and rhinorrhea. Nervousness occurred in 4% of the pseudoephedrine and acetaminophen recipients compared with 0% of placebo recipients (P =.007). CONCLUSION: Our results suggest that pseudoephedrine plus acetaminophen is effective for relief of symptoms attributable to the paranasal sinuses that may develop early in the course of a cold. Arch Fam Med. 2000;9:979-985

Acetaminophen↗
PubMed2004

Prevalence of migraine in patients with a history of self-reported or physician-diagnosed "sinus" headache.

BACKGROUND: Symptoms referable to the sinus area are frequently reported during migraine attacks, but are not recognized in diagnostic criteria. Underrecognition of migraine may be partly attributed to a variable clinical presentation, and migraines with "sinus" symptoms contribute to this problem. This study was conducted to determine the prevalence of migraine-type headache (International Headache Society [IHS]-defined migraine without aura [IHS 1.1], migraine with aura [IHS 1.2], or migrainous disorder [IHS 1.7]) in patients with a history of self-described or physician-diagnosed "sinus" headache. METHODS: During a clinic visit, patients with a history of "sinus" headache, no previous diagnosis of migraine, and no evidence of infection were assigned an IHS headache diagnosis on the basis of headache histories and reported symptoms. RESULTS: A total of 2991 patients were screened. The majority (88%) of these patients with a history of self-described or physician-diagnosed "sinus" headache were diagnosed at the screening visit as fulfilling IHS migraine criteria (80% of patients) or migrainous criteria (8% of patients). The most common symptoms referable to the sinus area reported by patients at screening were sinus pressure (84%), sinus pain (82%), and nasal congestion (63%). CONCLUSIONS: In this study, 88% of patients with a history of "sinus" headache were determined to have migraine-type headache. In patients with recurrent headaches without fever or purulent discharge, the presence of sinus-area symptoms may be part of the migraine process. Migraine should be included in the differential diagnosis of these patients.

Adolescent↗
PubMed2000

Paranasal sinus development and choanal atresia.

BACKGROUND: Although the determinates of paranasal sinus development and sinusitis are not well defined, a candidate factor is blockage of the choana. HYPOTHESIS: Maxillary sinuses ipsilateral to unilateral choanal atresia are comparatively small and have more evidence of sinusitis than do the contralateral sinuses. DESIGN: Retrospective. SETTING: Children's hospitals. PATIENTS: Sixteen nonsyndomic children with isolated unilateral congenital choanal atresia. MAIN OUTCOME MEASURES: Determination of maxillary sinus volumes and mucoperiosteal thickening on preoperative computed tomograms. RESULTS: Maxillary sinuses ipsilateral to unilateral choanal atresia have slightly larger volumes than, and mucoperiosteal thickening that is similar to, the contralateral sinuses. CONCLUSION: These data suggest that maxillary sinus development and sinusitis are independent of posterior nasal ventilation and drainage.

Adolescent↗
PubMed2000

Confirmations and surprises in the association of tobacco use with sinusitis.

OBJECTIVE: To generate estimates of sinusitis prevalence for adults in association with the use of tobacco or passive smoke exposure. DESIGN: Analysis of data from the Third National Health and Nutrition Examination Survey, 1988-1994. SETTING: Sample of the noninstitutionalized civilian population of the United States. PARTICIPANTS: A total of 20,050 adults aged 17 years or older. MAIN OUTCOME MEASURE: Presence of self-reported sinusitis or sinus problems. RESULTS: In the United States, 66 million adults, constituting 35% of the adult population, reported having sinusitis or sinus problems at least once during the previous 12 months. Female sex, non-Hispanic white or non-Hispanic black race, higher income levels, and progressively higher educational levels were associated with increased prevalence of sinusitis. The prevalence of both acute and recurrent or chronic sinusitis increased with direct cigarette and other tobacco use but did not rise with passive exposure to cigarette smoke. CONCLUSIONS: Consistent with data for other respiratory ailments, the direct use of tobacco confers a small increased risk of developing sinusitis in the adult population, but contrary to expectation, passive smoke does not. The demographic variables of sex, race/ethnicity, and educational level demonstrated unexpectedly strong associations with the prevalence of sinusitis and should be analyzed and controlled for in future studies of sinusitis.

Acute Disease↗
PubMed2004

Prevalence of the chronic sinusitis diagnosis in Olmsted County, Minnesota.

BACKGROUND: Commonly cited estimates from the National Health Interview Survey rank chronic sinusitis as one of the most prevalent chronic diseases in the United States. These data rely on patient self-reporting of the disease. However, chronic sinusitis is difficult to diagnose because its symptoms overlap those of many other disease processes. As such, these prevalence data may be unreliable. OBJECTIVE: To provide an estimate of the prevalence of chronic sinusitis based on assigned International Classification of Diseases, Ninth Revision (ICD-9) codes for the year 2000 in a population-based sample. This study establishes the individual patient as the unit of measure vs previous ICD-9-based estimates that measured physician encounters. DESIGN: Using existing databases, we identified all residents of Olmsted County, Minnesota, who were assigned an ICD-9 diagnosis code for chronic sinusitis (473.x) in the year 2000. SETTING: Primary care and referral center serving the general community. PARTICIPANTS: All residents of Olmsted County who provided research authorization were eligible. MAIN OUTCOME MEASURE: Age- and sex-specific prevalence of chronic sinusitis based on assigned ICD-9 diagnosis codes. RESULTS: In the year 2000, 2405 residents of Olmsted County were given an ICD-9 diagnosis code for chronic sinusitis. Among these, 1627 (67.7%) were female and 778 (32.3%) were male. The overall age- and sex-adjusted prevalence per 100,000 was 1955 (1.96%). The mean (SD) age at the time of diagnosis was 39.4 (17.6) years (age range, 4.2 months to 94 years). Eighty-seven percent were diagnosed at Mayo Clinic, and the balance were from the Olmsted Medical Center. At Mayo, family practitioners and internists diagnosed most of the cases (70%); only 8% were diagnosed by the Department of Otolaryngology. The diagnosis code 473.9 for unspecified chronic sinusitis made up 95% of cases. CONCLUSIONS: Current prevalence estimates of chronic sinusitis may be exaggerated. Chronic sinusitis has been reported to affect 14% to 16% of the US population according to a National Health Interview Survey. In Olmsted County, we found a much lower prevalence (1.96%) of chronic sinusitis using ICD-9 codes as an identifier.

Adult↗
PubMed1996

Bacteriology and beta-lactamase activity in acute and chronic maxillary sinusitis.

OBJECTIVE: To assess the bacteriology and beta-lactamase enzyme activity in aspirates of 10 acutely and 13 chronically inflamed maxillary sinuses. RESULTS: The predominant organisms isolated in acute sinusitis were Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, and those found in chronic sinusitis were Prevotella species, Fusobacterium species, and Peptostreptococcus species. Four beta-lactamase-producing organisms (BLPOs) were isolated in four specimens (40%) obtained from acutely inflamed sinuses, and 14 BLPOs were recovered from 10 chronically inflamed sinuses (77%). The predominant BLPOs in acute sinusitis were H influenzae, and M catarrhalis; those in chronic sinusitis were Staphylococcus aureus, Prevotella species, Fusobacterium species, and Bacteroides fragilis. CONCLUSIONS: Beta-lactamase activity was detected in 12 (three in acute and nine in chronic sinusitis) of the 14 aspirates that contained BLPOs. The detection of beta-lactamase activity in sinus aspirates provides support for the role of BLPOs in the failure of penicillin therapy in sinusitis.

Acute Disease↗
PubMed1997

Maxillary sinus mucosal blood flow during nasal vs tracheal respiration.

OBJECTIVE: To determine the effect of changes from nasal to tracheal respiration on maxillary sinus mucosal blood flow in rabbits with unobstructed sinus ostia. DESIGN: Animals underwent tracheotomy with a T tube and then a small window of intact maxillary sinus mucosa was exposed. Mucosal blood flow was recorded during normal nasal respiration using laser-Doppler velocimetry. At hourly intervals, respiration was changed from the nasal to the tracheal route and then back again. SUBJECTS: Ten anesthetized rabbits were used: 5 underwent single and 4 underwent multiple shifts in the respiratory route, while 1 was monitored continuously during long-term nasal breathing only. RESULTS: A significant decrease in maxillary sinus blood flow occurred on switching from nasal to tracheal respiration and a significant increase in blood flow occurred on return to nasal respiration. Where multiple switches were made, blood flow changes diminished in magnitude, but significant decreases (nasal to tracheal) or increases (tracheal to nasal) were evident in all cases. CONCLUSIONS: It is proposed that the maxillary sinus may act in an accessory capacity to the nose for humidification of inspired air via secretions liberated from the sinus ostium. Furthermore, we suggest that nasal airflow is involved with the reflex regulation of sinus blood flow, probably via stimulation of sensory receptors in the nasal cavity. Reduced maxillary sinus mucosal blood flow may thus contribute to supra-systemic levels of antral carbon dioxide. Since elevated carbon dioxide levels have been shown to reduce maxillary sinus mucociliary activity in vitro, nasal airflow compromise may contribute to the initiation of a cascade of pathophysiological events leading to acute sinusitis.

Animals↗
PubMed1984

Variation in the pattern of cranial venous sinuses and hominid phylogeny.

In 1967 Tobias noted that Australopithecus boisei cranium O.H.5 exhibited a cranial venous sinus pattern in which the occipital sinus and the marginal sinuses of the foramen magnum appeared to have replaced the transverse-sigmoid sinuses as the major venous outflow track. Specimens of A. robustus and several more recently recovered A. boisei crania also show evidence of enlarged occipital-marginal sinuses. In contrast, A. africanus and H. habilis retain a dominant transverse-sigmoid system that characterizes the great majority of extant apes and modern human cadaver samples. Pliocene A. afarensis exhibits a high frequency of occipital-marginal drainage systems. An examination of several series of precontact North American Indian crania shows that the frequency distribution of the occipital-marginal sinus pattern is spatiotemporally disjunct , ranging from 7.5% to 28%. The Late Pleistocene sample from P redmost , Czechoslovakia, also shows a very high incidence of occipital-marginal sinus patterns (approximately 45%). These observations suggest that occipital-marginal and transverse-sigmoid sinus patterns are adaptively equivalent character states. This conclusion is supported by the fact that enlarged occipital-marginal and transverse-sigmoid sinus systems often coexist on the same and/or contralateral sides of the head. It is well known that the frequencies of such adaptively neutral traits are often heavily influenced by population-specific epistatic interactions. The utilization of such traits in phylogenetic reconstruction entails a substantial risk of mistaking parallelism for synapomorphy . It is concluded that using functional-adaptive criteria in the definition of morphologic characters is a more reliable method to guide phylogeny reconstruction. In light of this, the distribution of venous sinus variants in Plio -Pleistocene hominids gives little or no basis for revising the phylogenetic scheme of Johanson and White (1979), or the functional-adaptive interpretation offered by White et al. (1981).

Animals↗
PubMed1988

Evidence for a dual pattern of cranial venous sinuses on the endocranial cast of Taung (Australopithecus africanus).

According to published accounts, an enlarged occipital-marginal sinus system is absent in Australopithecus africanus, although it occurs in high frequencies in A. robustus, A. Boisei, and Hadar hominids commonly designated A. afarensis. In this report, we describe, for the first time, an enlarged occipital-marginal sinus system on the endocranial cast of the Taung specimen, which is part of the holotype of A. africanus. In addition, well-developed right transverse and sigmoid sinuses are represented on the Taung endocast. The various components of the dual venous sinus system on the Taung endocast are measured, and the system is compared to those of other fossil hominids. The compresence of a lateral sinus system and enlarged occipital and marginal sinuses occurs in two Hadar specimens, 2 specimens of A. robustus crassidens, 1 A. boisei specimen, and several early H. sapiens crania. Hence, the presence of strong transverse sinus impressions in a fragmentary specimen may not be interpreted as an indication that an enlarged occipital-marginal sinus system was not present in the original specimen. Conversely, lack of transverse sinus grooves in a fragmentary specimen does provide indirect evidence than an enlarged occipital-marginal system would probably have been present in the whole specimen, as in 2 specimens of A. boisei. Including Taung, enlarged occipital and marginal sinuses occur in 1 out of 5, or 20%, of A. africanus specimens. This figure compares well with the range of mean frequencies in modern human cranial series (1.5 to 28%), but is much lower than are the frequencies for A. boisei, A. robustus, and the Hadar hominids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

The sinus of the dorsum sellae.

Dissections of cadaver heads and studies of specimens sectioned in horizontal (axial), coronal, or sagittal planes at low (5 X) magnification revealed a frequent venous sinus within the bone of the dorsum sellae in addition to the true dural sinuses. This sinus interconnected the cavernous sinuses on either side of the sella turcica and was continuous with the superior and inferior petrosal sinuses and the basilar plexus. The sinus was quite evident on venograms of five patients. In sagittal sections of 37 adult cadaver heads, the sinus was identified in 28 (76%) and was absent in nine (24%) in which there was pneumatization of the dorsum sellae by the sphenoid sinus. The intracranial sinus of the dorsum sellae is not a true dural sinus but is comparable to the basivertebral veins of the spine.

Cavernous Sinus↗
PubMed1983

Morphology of the rat carotid sinus nerve. I. Course, connections, dimensions and ultrastructure.

An analysis of the morphology of the carotid sinus nerve in 39 rats revealed that the nerve emerged from the glossopharyngeal nerve (nerve IX) 0.6-1.0 mm beyond the distal extent of the petrosal ganglion. In 68% of cases the nerve consisted of a single bundle of axons; two bundles were present in the other nerves. Near the rostral pole of the carotid body, the nerve divided into multiple bundles of axons. Most axon bundles entered the carotid body, but some instead joined sympathetic nerves from the superior cervical ganglion. Some of the latter group of sinus nerve axons innervated the wall of the carotid sinus. Other presumptive baroreceptor axons reached the carotid sinus from the sinus nerve by first traversing the carotid body. The sinus nerve had an average length of 2.0 +/- 0.13 mm (mean +/- S.E.M., range = 1.3-2.9 mm, N = 15) and was elliptical in cross-section (major axis = 77 microns, minor axis = 46 microns). The nerve contained an average of 625 axons, 86% of which were unmyelinated. The perineurial sheath that enveloped the circumference of the nerve was comprised of 3 or 4 layers of cells interconnected by gap junctions and tight junctions. Near the carotid body, the perineurium extended into the nerve where it compartmentalized fascicles of axons. The endoneurium consisted mainly of collagenous fibres (mean diameter 40 nm) that were only half the size of those outside the perineurium. Endoneurial connective tissue cells were sparse, being only 5% as numerous as Schwann cells. The one blood vessel in the nerve (mean luminal diameter 12.4 +/- 1.2 microns) usually arose from vessels in nerve IX and terminated in a venule at the rostral surface of the carotid body. Ganglion cells were located in nerve IX near the origin of the sinus nerve and along the length of the sinus nerve itself. All ganglion cells examined were postsynaptic to vesicle-containing nerve terminals, and therefore were presumed to be autonomic rather than sensory. Ganglion cells were more numerous in terminal branches of the sinus nerve on the ventral surface of the carotid body. Most other ganglion cells in the carotid body were located among axons of the ganglioglomerular nerve, although some were associated with a small branch of the vagus nerve. Paraganglia were located within the sinus nerve in 15% of cases, and in another 10% of cases they were found nearby in nerve IX. The paraganglia, which measured approximately 50 X 50 X 100 microns, were innervated by axons that resembled sensory nerves of the carotid body.

Animals↗
PubMed1994

Synaptic connections of central carotid sinus afferents in the nucleus of the tractus solitarius of the rat. II. Connections with substance P-immunoreactive neurons.

A combined transganglionic transport and immunocytochemical technique was used to study the synaptic morphology of central carotid sinus afferents and substance P-immunoreactive neurons in the commissural subnucleus of the nucleus of the tractus solitarius in rats. A large population of substance P-immunoreactive neurons (88.32%) were seen in close association with central carotid sinus afferents by light microscopy. However, many labelled central carotid sinus afferents appeared not associated with substance P-immunoreactive neurons in the nucleus of the tractus solitarius. Substance P-immunoreactive neurons were spindle, pear, or oval-shaped with a short axis ranging from 5 to 11 microns. Their long axis was oriented predominantly in a lateral-medial direction along the path of the central carotid sinus afferents from the solitary tract to the midline. Synaptic contacts between central carotid sinus afferents and substance P-structures, including dendritic profiles of different calibers and somas, were readily found by electron microscopy. Many central carotid sinus afferents were also found in synaptic contact with non-immunoreactive dendrites and somas. Appositions between central carotid sinus afferents and unlabelled axon terminals were common, but only in a few cases were morphological manifestations of synapses revealed. In the latter, the substance P-immunoreactive terminals appeared mostly presynaptic but postsynaptic ones were also encountered. Our data provide the evidence that some of the substance P-immunoreactive cells in the nucleus of the tractus solitarius are 2nd order neurons of the carotid sinus afferent pathway. The possibility that some of the substance P-immunoreactive neurons in the nucleus of the tractus solitarius may be interneurons and mediate carotid sinus afferent inputs to catecholaminergic neurons in the nucleus of the tractus solitarius is considered. Our findings also provide an anatomical substrate for a possible presynaptic modulatory role of central carotid sinus afferents on the inputs from other brain centers to the substance P-neurons in the nucleus of the tractus solitarius.

Afferent Pathways↗
PubMed1991

The posterior wall of the maxillary sinus as seen in panoramic radiography.

The dental and sinus projection programs of the PM 2002cc panoramic x-ray unit were compared with regard to the visualization of the maxillary sinus posterior wall of a dried skull. The posterior wall of the maxillary sinus appeared different on each program. In the sinus projection program the posterior wall appeared narrower than that in the dental projection program. The main cause for the difference of the maxillary sinus posterior wall image was the projection angle. In the sinus projection x-rays entered more tangentially to the posterior wall of the sinus than in the dental projection, but in the dental projection x-rays entered more tangentially to the mediosuperior and medioinferior region of the maxillary sinus posterior wall. Thus a large, widely destructive lesion in the posterior wall of the maxillary sinus would be more easily detected with the sinus projection. On the other hand, lesions confined to the mediosuperior and medioinferior regions of the posterior wall will be depicted more clearly with the dental projection program.

Humans↗
PubMed1996

Depressed baroreflex in heart failure is not due to structural change in carotid sinus nerve fibers.

It is well known that the baroreceptor reflex is blunted in the heart failure state. However, the mechanisms for this depression are not well understood. The aim of the present study was to determine if carotid sinus nerve fiber density is decreased in the heart failure state. Experiments were carried out in pacing-induced heart failure and normal dogs. The carotid sinus nerve (CSN) was dissected and the CSN discharge responses to changes in arterial pressure with nitroglycerin (25 micrograms/kg, i.v.) or phenylephrine (10 micrograms/kg, i.v.) were recorded. Thereafter, the carotid sinus area was isolated and perfused with oxygenated Krebs-Henseleit solution. Carotid sinus baroreceptor single-unit activity was recorded and a carotid sinus pressure-discharge curve was constructed using either static or pulsatile pressure. Finally, the carotid sinus nerve was removed and fixed at its in situ length in 3% glutaraldehyde. The fixed carotid sinus nerve was cut transversely in 0.5-1.0-micron sections and prepared for electron microscopy. A photographic collage of the CSN was then analyzed at 4000 x magnification. The total number, diameter and area of myelinated and non-myelinated fibers were measured with a digitizer and the density and diameter distribution were calculated. Carotid sinus nerve discharge responses to change in arterial pressure were significantly blunted in dogs with pacing-induced heart failure. Furthermore, single-unit baroreceptor responses to both static and pulsatile pressurization were markedly depressed in dogs with heart failure. However, there was no change in either fiber density or the ratio of myelinated fibers to unmyelinated fibers in the carotid sinus nerve in heart failure. In addition, there was no change in the distribution of either fiber diameter or cross-sectional area in the carotid sinus nerve in dogs with heart failure. These data indicate that there is no significant change in the number or type of fibers in the CSN of dogs with heart failure. Therefore, the depressed baroreceptor reflex in heart failure is not due to structural changes in fibers of the CSN. The depressed baroreflex is most likely due to desensitization of individual baroreceptors.

Animals↗