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Biomedical subjects

A O'Connor

Publications and source records attributed to A O'Connor.

At least 55 records · Page 3Linked to original sources

Substance P is generated in vivo following nasal challenge of allergic individuals with bradykinin.

BACKGROUND: Bradykinin, a potent inflammatory mediator, is released during allergic and non-allergic rhinitis and asthma in man. Nasal bradykinin challenge induces a dose-dependent plasma leakage into the nasal cavity and relevant symptoms of rhinitis. OBJECTIVE: We now report on substance P generation during nasal bradykinin challenge in vivo. METHODS: The effect of locally applied bradykinin on substance P generation was studied in nine individuals, allergic to grass pollen and six non-allergic controls. In the allergics TAME-esterase activity, histamine and substance P concentrations were measured in nasal lavages and correlated to the clinical symptoms. RESULTS: Substance P concentrations in nasal lavages increased in a dose-dependent fashion during nasal bradykinin challenge in both groups. In the allergic group Substance P-increases correlated with the production of TAME-esterase activity (r = 0.9, P < 0.05) whereas these allergic individuals did not produce any histamine increases. The generation of substance P and the increase of TAME-esterase activity was associated with the onset of clinical symptoms. Correlation of oedema and hypersecretion to substance P were significant by linear regression analysis (r = 0.88, P < 0.005 and r = 0.89, P < 0.02, respectively). Bradykinin induced irritations like burning and itching were short-term and rare. Serial dilutions of nasal washes produced Substance P-RIA displacement curves that paralleled the standard curve and recovery of standard substance P that was added to nasal washes was 76 +/- 4% (mean +/- SEM), n = 8. CONCLUSION: Bradykinin induces in vivo a dose-dependent plasma leakage into the nasal cavity without affecting mast cells, but stimulates nerve endings resulting in the release of the neuropeptide substance P.

Adolescent↗

Warfarin for atrial fibrillation. The patient's perspective.

OBJECTIVE: To determine the minimal clinically important difference (MCID) of warfarin therapy for the treatment of nonvalvular atrial fibrillation from the perspective of patients using 2 different elicitation methods. DESIGN: All patients completed 2 face-to-face interviews, which were 2 weeks apart. For each interview, they were randomized to receive 1 of 2 elicitation methods: ping-ponging or starting at the known efficacy. SETTING: The practices of 2 university-affiliated family medicine centers (8 physicians each), 14 community-based family physicians, and 2 cardiologists. PATIENTS: Sixty-four patients with nonvalvular atrial fibrillation who were initiated with warfarin therapy at least 3 months before the study. INTERVENTION: During each interview, the patients' MCIDs were determined by using (1) a pictorial flip chart to describe atrial fibrillation; the consequences of a minor stroke, a major stroke, and a major bleeding episode; the chance of stroke if not taking warfarin; the chance of a major bleeding episode if taking warfarin; examples of the inconvenience, minor side effects, and costs of warfarin therapy; and then (2) 1 of the 2 elicitation methods to determine their MCIDs (the smallest reduction in stroke risk at which the patients were willing to take warfarin). Patients' knowledge of their stroke risk, acceptability of the interview process, and factors determining their preferences were also assessed. MAIN RESULTS: Given a baseline risk of having a stroke in the next 2 years, if not taking warfarin, of 10 of 100, the mean MCID was 2.01 of 100 (95% confidence interval, 1.60-2.42). Fifty-two percent of the patients would take warfarin for an absolute decrease in stroke risk of 1% over 2 years. Before eliciting their MCIDs, patients showed poor knowledge of their stroke risk, which improved afterward. The interview process was well accepted by the patients. The MCID using the ping-ponging elicitation method was 1.015 of 100 smaller compared with use of the starting at the known efficacy method (P = .01). CONCLUSIONS: We were able to determine the MCID of warfarin therapy for the prevention of stroke from the perspective of patients with nonvalvular atrial fibrillation. Their MCIDs were much smaller than those that have been implied by some experts and clinicians. The interview process, using the flip chart approach, appeared to improve the patients' knowledge of their disease and its consequences and treatment. The method used to elicit the patients' MCIDs can have a clinically important effect on patient responses. The method used in our study can be generalized to other conditions and, thus, could be helpful in 3 ways: (1) from a clinical decision-making perspective, it could facilitate patient-physician communication; (2) it could clarify the patient perspective when interpreting the results of previously completed trials; and (3) it could be used to derive more clinically relevant sample sizes for randomized treatment trials.

Aged↗

DNA double strand breaks in epidermal cells cause immune suppression in vivo and cytokine production in vitro.

UV irradiation of the skin causes immune suppression by a mechanism involving epidermal cytokines. To determine the role of epidermal DNA damage in immune suppression, we used HindIII restriction endonuclease encapsulated in liposomes to cause DNA strand breaks in epidermal cells in vivo and in vitro. Topical application of HindIII in liposomes to murine skin in vivo impaired the induction of contact hypersensitivity responses initiated either locally or at distant sites and impaired the function of APCs. Unlike UV-B radiation, however, treatment of mice with HindIII in liposomes before contact sensitization did not induce tolerance or transferable suppression. The liposome-encapsulated HindIII caused double strand breaks in DNA and induced IL-10 and TNF-alpha production when added to cells of a murine keratinocyte line in vitro. Topical application of liposomal HindIII also induced TNF-alpha in the epidermis of mice. Liposomes containing heat-inactivated HindIII or an endonuclease specific for pyrimidine dimers in DNA did not exhibit these effects. These results support the hypothesis that DNA damage is a trigger for the production of cytokines that modulate immune responses. They also suggest that immune suppression and suppressor cell induction are separate consequences of cutaneous injury that require different stimuli.

Animals↗

High-dose chemotherapy with autologous stem cell rescue in breast cancer.

BACKGROUND: Because metastatic breast cancer is a lethal disease despite some responsiveness to systemic chemotherapy, high-dose chemotherapy with autologous stem cell rescue is being utilized with increasing frequency. This analysis was undertaken to determine the outcome for such patients treated with intensive chemotherapy between 1989-1994, at the Hoag Cancer Center in Newport Beach, CA. METHODS: During 1989, only patients with metastatic disease who had failed more than two standard breast cancer chemotherapy regimens were considered eligible for such treatment. They received high-dose BCNU/cyclophosphamide/cisplatinum chemotherapy with autologous bone marrow rescue. After January 1990, patients with metastatic disease were eligible only if they had received limited prior chemotherapy and demonstrated responsiveness to induction chemotherapy. Beginning June 1990, patients with metastatic disease were to receive mitoxantrone and thiotepa (MiTepa) followed by peripheral blood stem cell rescue, then ifosfamide, carboplatin and etoposide (ICE) chemotherapy followed by peripheral blood stem cell rescue. High-risk adjuvant patients were to receive one course of ICE followed by rescue. RESULTS: Between 1/89-12/94, 48 breast cancer patients underwent 65 intensive chemotherapy treatments followed by autologous stem cell rescue. During 1989, three of the eight patients with metastatic disease died within 60 days because of therapy-related complications. The longest failure-free survival (FFS) of these eight was 12.2 months, and the longest overall survival (OS) 20.5 months. Since 1/90, one physician has treated 24 patients with metastatic breast cancer, 17 of whom actually underwent two successive transplants with MiTepa/ICE. For the latter group, median FFS is 23.2 months; median OS is 39.7 months. There were no acute deaths, but two patients died > 60 days after initial transplant from therapy-related complications, veno-occlusive disease (5.2 months) and myelodysplastic syndrome (30.5 months), while five died of progressive disease at 22.5, 32.8, 39.4, 46.3, and 51.3 months. For the 24 metastatic patients treated 1990-1994, 1-, 2-, and 3-year FFS rates are 86%, 40%, and 17%, respectively, while OS rates are 91%, 80%, and 65%. Of 11 patients treated in the adjuvant setting, only one has relapsed (9.8 months) with follow-up from 3-61 months. CONCLUSIONS: Modifications made in the program, including selection of patients responsive to induction chemotherapy, transfusion of peripheral blood stem cells, implementation of hematopoietic colony stimulating factors, and use of tandem intensive treatments has been associated with a low rate of acute morbidity and encouraging survival rates.

Adult↗

Determination of substance P in human nasal lavage fluid.

The determination of substance P (SP) concentrations in human nasal lavages can be used to monitor physiological and certain pathophysiological processes in human airway mucosa. But, because of the low concentrations, immunoassays of high sensitivity are needed. Two approaches to improve the sensitivity of the radioimmunological determinations of SP are compared: increasing the sample volume and miniaturizing the assay design. The characterization of SP-like immunoreactivity (SP-LIR) in human nasal lavage was performed by investigating the immunological specificity of the antibody used in the radioimmunoassays and by reversed-phase high-performance liquid chromatography separation of the SP-LIR. SP concentrations in nasal lavages can be reliably measured by each of the two introduced RIA methods. Despite the lower detection limit of the miniaturized immunoassay (0.2 in comparison to 1.3 fmol/incubate) it is advisable to increase the sample volume in order to improve the sensitivity because of the higher precision of the determinations. SP-LIR was found in nasal lavage specimens in concentrations between 2 and 10 fmol/ml and consisted of authentic SP and, to a less extent, SP-sulfoxide.

Chromatography, High Pressure Liquid↗

Enzyme therapy of xeroderma pigmentosum: safety and efficacy testing of T4N5 liposome lotion containing a prokaryotic DNA repair enzyme.

Xeroderma pigmentosum (XP) is a rare genetic disease in which patients are defective in DNA repair and are extremely sensitive to solar UV radiation exposure. A new treatment approach was tested in these patients, in which a prokaryotic DNA repair enzyme specific for UV-induced DNA damage was delivered into the skin by means of topically applied liposomes to supplement the deficient activity. Acute and chronic safety testing in both mice and humans showed neither adverse reactions nor significant changes in serum chemistry or in skin histology. The skin of XP patients treated with the DNA repair liposomes had fewer cyclobutylpyrimidine dimers in DNA and showed less erythema than did control sites. The results encourage further clinical testing of this new enzyme therapy approach.

Adolescent↗

Induction of granulocytic differentiation in a mouse model by benzene and hydroquinone.

Chronic exposure of humans to benzene causes acute myelogenous leukemia (AML). The studies presented here were undertaken to determine whether benzene, or its reactive metabolite, hydroquinone (HQ), affects differentiation of myeloblasts. Benzene or HQ administered to C57BL/6J mice specifically induced granulocytic differentiation of myeloblasts. The ability of these compounds to induce differentiation of the myeloblasts was tested directly using the murine interleukin 3 (IL-3)-dependent 32D.3 (G) myeloblastic cell line, and the human HL-60 promyelocytic leukemia cell line. We have previously shown that benzene treatment of HL-60 myeloblasts activates protein kinase C (PKC) and upregulates the 5-lipoxygenase (LPO) pathway for the production of leukotriene D4 (LTD4), an essential effector or granulocytic differentiation. Differentiation was prevented by sphinganine, a PKC inhibitor, and, as shown here, by LPO inhibitors and LTD4 receptor antagonists. Benzene or HQ also induces differentiation in 32D.3 (G) myeloblasts. Both compounds interact with cellular signaling pathways normally activated by granulocyte colony stimulating factor (G-CSF) and can replace the requirement for G-CSF. While IL-3 induces a growth response in 32D.3 (G) cells, G-CSF has been shown to provide both growth and differentiated signals. Both HQ and LTD4 induce differentiation and synergize with IL-3 for growth; however, neither supports growth in the absence of IL-3. Benzene, like HQ, also provides a differentiation signal for 32D cells; however, it has no effect on their growth. Unlike G-CSF, benzene, or LTD4, each of which stimulates terminal differentiation; HQ blocks differentiation at the myelocyte stage, allowing only a small percentage of progenitors to proceed to mature segmented granulocytes. Benzene- and G-CSF-induced differentiation were prevented by the additional of either LPO inhibitors or LTD4 receptor antagonists, indicating that benzene, like G-CSF, upregulates LTD4 production. Hydroquinone-induced differentiation was not affected by the LPO inhibitors, but only by the specific receptor antagonists. Thus HQ appears to obviate the requirement for LTD4 by activating the LTD4 receptor directly.

Animals↗

Validation of client decision-making instruments in the context of psychiatry.

We evaluated the psychometric properties of instruments measuring decisional conflict, decision self-efficacy, and decision emotional control with 94 clients diagnosed with schizophrenia who were considering the continuation of treatment with long-acting antipsychotic injections. The decision scales had adequate internal consistency (range 0.78 to 0.84) and discriminated significantly (p < 0.000 to 0.037) between clients who expressed certainty and those who expressed uncertainty regarding decisions to continue with treatment. The scales may be useful in psychiatric populations, in identifying the factors contributing to difficulty in decision-making regarding treatment and evaluating decision-supporting interventions.

Adult↗

Biochemical consequences of resistance to a recently discovered IMP dehydrogenase inhibitor, benzamide riboside, in human myelogenous leukemia K562 cells.

Benzamide riboside (BR) exhibits potent antitumor activity in a variety of cultured human tumor cells. The drug is metabolized to benzamide adenine dinucleotide (BAD), which in turn functions as a selective inhibitor of IMP dehydrogenase (IMPDH) activity with a Ki of 0.118 microM. In vitro, BR is a more potent antitumor inhibitor of IMPDH than tiazofurin, another IMPDH inhibitor which has shown significant oncolytic activity in adult patients with end-stage leukemia. To elucidate the mechanism of resistance, a variant of human myelogenous leukemia K562 cells was developed by subculturing sensitive cells in sublethal concentrations of BR over 60 generations. The BR resistant line that emerged exhibited an IC50 (a concentration producing 50% reduction in cell proliferation) of 148 microM, compared to the sensitive line which had an IC50 of 1.6 microM. The activity of the target enzyme, IMPDH, was increased 3-fold in the resistant variant. Studies on BR metabolism revealed that resistant cells formed only 18% of the active metabolite, BAD, compared to sensitive cells. This finding, in turn, correlated with the specific activity of NAD pyrophosphorylase (the enzyme responsible for the synthesis of BAD) which was reduced to undetectable levels in the resistant variant. The basal levels of NAD and guanylates were also significantly decreased to 41% and 48%, respectively, in the resistant line compared to the parent line. Additionally, after treatment with BR a decrease in guanylate level was observed only in the sensitive cells. Sensitive and resistant cells exhibit comparable cytotoxicity to agents outside the tiazofurin family, suggesting that a multidrug resistance was unlikely to explain the resistance to BR. Moreover, BR resistant cells exhibit collatoral sensitivity to 6-aminopurine, cytarabine and 5-fluorouracil, which have different mechanisms of action. In conclusion, these studies establish that the primary mechanism of resistance to BR involves an increase in IMPDH (target enzyme) activity with a concurrent decrease in NAD pyrophosphorylase (BAD synthetic enzyme) activity.

Adult↗

The promoter of the gene Itr1 from barley confers a different tissue specificity in transgenic tobacco.

Tissue-specific expression of the gene coding for trypsin inhibitor BTI-CMe in barley (Itr1) occurs during the first half of endosperm development. In transgenic tobacco, the Itr1 promoter drives expression of the beta-glucuronidase reporter gene not only in developing endosperm but also in embryo, cotyledons and the meristematic intercotyledonary zone of germinating seedlings. A promoter fragment extending 343 bp upstream of the translation initiation ATG codon was sufficient for full transgene expression, whereas, the proximal 83 bp segment of the promoter was inactive. Possible reasons for the differences in expression patterns are discussed.

Base Sequence↗

Furanfurin and thiophenfurin: two novel tiazofurin analogues. Synthesis, structure, antitumor activity, and interactions with inosine monophosphate dehydrogenase.

The syntheses of furan and thiophene analogues of tiazofurin (furanfurin and thiophenfurin, respectively) are described. Direct stannic chloride-catalyzed C-glycosylation of ethyl 3-furan-carboxylate (6) or ethyl 3-thiophencarboxylate (18) with 1,2,3,5-tetra-O-acetyl-D-ribofuranose gave 2- and 5-glycosylated regioisomers, as a mixture of alpha- and beta-anomers, and the beta-2,5-diglycosylated derivatives. Deprotection of ethyl 5-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)furan-3-carboxylate (9 beta) and ethyl 5-(2,3,5-tri-O-acetyl-beta-D-ribofuranosyl)thiophene-3-carboxylate (20 beta) with sodium ethoxide afforded ethyl 5-beta-D-ribofuranosylfuran-3-carboxylate (12 beta) and ethyl 5-beta-D-ribofuranosylthiophene-3-carboxylate (23 beta) which were converted into 5-beta-D-ribofuranosylfuran-3-carboxamide (furanfurin, 4) and 5-beta-D-ribofuranosylthiophene-3-carboxamide (thiophenfurin, 5) by reaction with ammonium hydroxide. The anomeric configuration and the site of glycosylation were established by 1H-NMR and proton-proton nuclear Overhauser effect difference spectroscopy. The structure of compound 23 beta was confirmed by X-ray crystallography. Thiophenfurin was found to be cytotoxic in vitro toward murine lymphocytic leukemia P388 and L1210, human myelogenous leukemia K562, human promyelocytic leukemia HL-60, human colon adenocarcinoma LoVo, and B16 melanoma at concentrations similar to that of tiazofurin. In the same test furanfurin proved to be inactive. Thiophenfurin was found active in vivo in BD2F1 mice inoculated with L1210 cells with a % T/C of 168 at 25 mg/kg. K562 cells incubation with thiophenfurin resulted in inhibition of inosine monophosphate (IMP) dehydrogenase (63%) and an increase in IMP pools (6-fold) with a concurrent decrease in GTP levels (42%). Incubation of adenosine-labeled K562 cells with tiazofurin, thiophenfurin, and furanfurin resulted in a 2-fold higher NAD analogue formulation by thiophenfurin than by tiazofurin. Furanfurin was converted to the NAD analogue with only 10% efficiency. The results obtained support the hypothesis that the presence of S in the heterocycle in position 2 with respect to the glycosidic bond is essential for the cytotoxicity and IMP dehydrogenase activity of tiazofurin, while the N atom is not.

Animals↗

Benzene and its metabolite, hydroquinone, induce granulocytic differentiation in myeloblasts by interacting with cellular signaling pathways activated by granulocyte colony-stimulating factor.

Chronic exposure of humans to benzene (BZ) causes acute myelogenous leukemia. These studies determined whether BZ, or its reactive metabolite, hydroquinone (HQ), affect differentiation of myeloblasts. BZ or HQ administered to C57BL/6J mice specifically induced terminal granulocytic differentiation of myeloblasts. The ability of the compounds to induce differentiation of the myeloblast was tested directly using the murine interleukin 3 (IL-3)-dependent myeloblastic cell line, 32D.3 (G) and the human HL-60 promyelocytic leukemic cell line. Treatment of HL-60 myeloblasts with BZ activated protein kinase C and upregulated the 5-lipoxygenase (LPO) pathway for the production of leukotriene D4 (LTD4), an essential effector of granulocytic differentiation. Differentiation was prevented by sphinganine, a kinase C inhibitor, as well as by LPO inhibitors and LTD4 receptor antagonists. BZ and HQ also induced differentiation in 32D.3 (G) myeloblasts. Both compounds interact with cellular signaling pathways activated by granulocyte colony-stimulating factor (G-CSF) and thus replace the requirement for G-CSF. IL-3 induces a growth response, whereas G-CSF provides both growth and differentiation signals. BZ does not induce growth in the absence of IL-3, but provides a differentiation signal. Both HQ and LTD4 induce differentiation and synergize with IL-3 for growth, however, neither support growth in the absence of IL-3. BZ-induced 32D cells showed a gradual progression of progenitor differentiation to granulocytes similar to that seen with G-CSF or LTD4. HQ blocks differentiation at the myelocyte stage; only a small percentage of progenitors proceed to granulocytes. BZ, like G-CSF, upregulates LTD4 production, whereas HQ obviates the requirement for LTD4 by activating the LTD4 receptor.

Animals↗

Effect of theophylline on beta-adrenergic receptor density and cAMP content in bovine aortic smooth muscle cells.

Activation of vascular beta-adrenergic receptors prevents an increase in vascular permeability caused by free radicals or inflammatory peptides. Methylxanthines seem to have similar protective effects on vascular endothelium. In the present study we investigated the effect of theophylline on the beta-adrenergic receptor expression and cAMP concentrations in cultured endothelial and smooth muscle cells from bovine aorta. Comparable values for beta-receptor density and binding affinity were detected in both cell types. Isoproterenol induced significant downregulation of beta-receptors in endothelial (BAEC: -60.5%) and smooth muscle cells (BASMC: -52.5%; P < 0.01). Incubation of endothelial cells with theophylline (4 micrograms/ml and and 40 micrograms/ml) for 24 hours did not affect beta-receptor expression, whereas in smooth muscle cells the beta-receptor density was reduced for -31.5% and -28.7%, respectively. In endothelial cells a transient effect on cAMP concentrations was observed after stimulation with isoproterenol (1 microM), but no effect was found in theophylline treated endothelial cells. Stimulation of intact smooth muscle cells with isoproterenol and theophylline (4 micrograms/ml and 40 micrograms/ml) resulted in a significant increase of cAMP concentrations after 60 and 240 minutes. The present data suggest a novel, celltype specific effect of theophylline on the beta-adrenergic receptor expression in vascular smooth muscle cells in vitro.

Adrenergic beta-Agonists↗

Technology assessment. Old, new, and needs-based.

Recent health reports, including the 1993 World Development Report, have emphasized the importance of integrating the needs of the population into technology assessment. This paper reviews previous approaches to technology assessment and identifies the missing link between technology and its impact on the physical, emotional, and social needs of the community, namely needs-based technology assessment. It stresses the key role played by issues of equity and community values in making technology decisions. A number of models for needs-based technology assessment are described.

Community Health Planning↗

The integration of high-dose chemotherapy and biotherapy: initial 5-year experience with autologous bone marrow transplantation in a comprehensive community cancer center.

Perhaps the best example of the integration of chemotherapy and biotherapy is autologous stem cell rescue following high dose chemotherapy. This analysis was undertaken to determine the outcome for patients treated in an autologous bone marrow transplant program, which was initiated in January 1989, and to illustrate the impact which biological response modifiers have had on the toxicity, survival, and costs associated with this aggressive treatment approach. Patients with metastatic cancer and good performance status were treated according to disease-specific treatment protocols. Peripheral blood stem cells [PBSC] came into use in 1990, hematopoietic colony stimulating factors [CSFs] in 1991. Outcome was monitored prospectively from the inception of the program. Five years after the program's inception, 75 patients had undergone 96 intensive chemotherapy treatments followed by autologous PBSC rescue. This included 35 patients with breast cancer, 15 with lymphoma or Hodgkin's Disease, five ovary, four melanoma, three sarcoma, three lung cancer, three leukemia, three testicular, two myeloma, one non-lung small cell carcinoma, and one medulloblastoma. Twenty-one patients underwent back-to-back cycles of intensive therapy and rescue; 14 of whom had breast cancer. Twelve patients were treated in 1989, 14 in 1990, 18 in 1991, 14 in 1992, and 17 in 1993. While four of the first 12 patients died within 60 days of reinfusion of cells in 1989, no patients have died within this time frame as a direct result of therapy during the subsequent four years. No patients have been lost to follow-up. Median survival was only eight months in 1989, but has not been reached for subsequent years. For all patients, median failure-free survival (FFS) is 17.2 months; 1-year FFS is 57%, 2-year 36%, and 3-year 29%. Median overall survival (OS) is 30.4 months; 1-year OS 66%, 2-year 52%, and 3-year 42%. From 1990-1993, for patients with metastatic breast cancer (21), and recurrent lymphoma (15), FFS and OS are comparable to the best results published from academic teaching hospitals. Twenty-one patients have survived over two years, 18 of whom continue in remission. Patients were hospitalized for an average of 31 days in 1989, 28.9 in 1990, 24.5 in 1991, and only 13.0-14.0 days in 1992-1993. Two patients were treated entirely as outpatients. Average hospital charges for the 96 treatments have been $120,000 with a range of $15,000 to $461,000, and currently average around $100,000.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Forensic psychiatry and elderly people--a retrospective review.

Elderly offenders have rarely been studied. We describe a population of elderly offenders referred to a forensic psychiatric service over a 20-year period (1972-1992). Patients over 65 years charged with a criminal offence were eligible for inclusion. For the purpose of the study they were divided into four study groups. Demographic data, forensic and psychiatric history, alcohol abuse, charge and psychiatric diagnosis are reported. The possible reasons for the high proportion of sex offences are discussed. Difficulties were encountered in the transfer of longstay elderly offenders back to their local area. Finally, we recommend that most of the elderly patients referred to the forensic service for treatment would best be cared for in their local catchment area hospital rather than in a high security hospital.

Aged↗

Analysis of intrabolus forces in patients with Zenker's diverticulum.

This report presents 10 patients with Zenker's diverticulum who were evaluated with simultaneous solid-state manometry and fluoroscopy. With this method, intrabolus forces are determined. Each patient had abnormal intrabolus forces regardless of the size of the diverticulum and cricopharyngeal muscle dysfunction. In the literature, there has been conflicting manometry results when studying Zenker's diverticulum. The use of analysis of intrabolus forces increases the sensitivity of manometric evaluation. This study establishes pressure abnormality in the pharyngoesophageal segment of patients with Zenker's diverticulum. The pathogenesis of Zenker's is presented based on these findings.

Deglutition↗