Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Neurocrit Care ; 35(1): 139-152, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33236290

RESUMO

BACKGROUND: Diagnosis of intensive care unit acquired weakness (ICUAW) is challenging. Pathogenesis of underlying critical illness polyneuromyopathy (CIPNM) remains incompletely understood. This exploratory study investigated whether longitudinal neuromuscular ultrasound examinations and cytokine analyses in correlation to classical clinical and electrophysiological assessment contribute to the understanding of CIPNM. METHODS: Intensive care unit patients were examined every 7 days until discharge from hospital. Clinical status, nerve conduction studies, electromyography as well as ultrasound of peripheral nerves and tibial anterior muscle were performed. Cytokine levels were analyzed by a bead-based multiplex assay system. RESULTS: Of 248 screened patients, 35 patients were included at median of 6 days (IQR: 8) after admission to intensive care unit. Axonal damage was the main feature of CIPNM. At the peak of CIPNM (7 days after inclusion), nerve ultrasound showed cross-sectional area increase of tibial nerve as a sign of inflammatory edema as well as hypoechoic nerves as a possible sign of inflammation. Cytokine analyses showed signs of monocyte and macrophage activation at this stage. Fourteen days after inclusion, cytokines indicated systemic immune response as well as profiles associated to neovascularization and regeneration. CONCLUSIONS: Exploratory neuromuscular ultrasound and cytokine analyses showed signs of inflammation like macrophage and monocyte activation at the peak of CIPNM followed by a systemic immune response parallel to axonal damage. This underlines the role of both axonal damage and inflammation in pathogenesis of CIPNM.


Assuntos
Doenças Musculares , Polineuropatias , Estado Terminal , Citocinas , Humanos , Unidades de Terapia Intensiva , Debilidade Muscular , Polineuropatias/diagnóstico por imagem , Ultrassonografia
3.
Diabetes Care ; 40(10): 1314-1322, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28751547

RESUMO

OBJECTIVE: Diabetes frequently develops in patients with chronic pancreatitis. We examined the alterations in the glucagon response to hypoglycemia and to oral glucose administration in patients with diabetes due to chronic pancreatitis. RESEARCH DESIGN AND METHODS: Ten patients with diabetes secondary to chronic pancreatitis were compared with 13 patients with type 2 diabetes and 10 healthy control subjects. A stepwise hypoglycemic clamp and an oral glucose tolerance test (OGTT) were performed. RESULTS: Glucose levels during the OGTT were higher in patients with diabetes and chronic pancreatitis and lower in control subjects (P < 0.0001). Insulin and C-peptide levels were reduced, and the glucose-induced suppression of glucagon was impaired in both groups with diabetes (all P < 0.0001 vs. control subjects). During hypoglycemia, glucagon concentrations were reduced in patients with chronic pancreatitis and with type 2 diabetes (P < 0.05). The increase in glucagon during the clamp was inversely related to the glucose-induced glucagon suppression and positively related to ß-cell function. Growth hormone responses to hypoglycemia were lower in patients with type 2 diabetes (P = 0.0002) but not in patients with chronic pancreatitis. CONCLUSIONS: α-Cell responses to oral glucose ingestion and to hypoglycemia are disturbed in patients with diabetes and chronic pancreatitis and in patients with type 2 diabetes. The similarities between these defects suggest a common etiology.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Células Secretoras de Insulina/patologia , Pancreatite Crônica/sangue , Adulto , Idoso , Glicemia/metabolismo , Peptídeo C/sangue , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Glucagon/sangue , Glucagon/metabolismo , Teste de Tolerância a Glucose , Humanos , Hipoglicemia/sangue , Hipoglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina/sangue , Insulina/metabolismo , Secreção de Insulina , Masculino , Pessoa de Meia-Idade , Pancreatite Crônica/fisiopatologia
4.
Scand J Trauma Resusc Emerg Med ; 25(1): 68, 2017 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-28693536

RESUMO

BACKGROUND: The effects of target temperature management (TTM) on the heart aren't thoroughly studied yet. Several studies showed the prolongation of various ECG parameters including Tpeak-Tend-time under TTM. Our study's goal is to evaluate the acute and long-term outcome of these prolongations. METHODS: In this study we included patients with successful resuscitation after cardiac arrest who were admitted to the Charité Virchow Klinikum Berlin or the Heart and Vascular Centre of the Ruhr University Bochum between February 2006 and July 2013 (Berlin) or May 2014 to November 2015 (Bochum). For analysis, one ECG during TTM was recorded after reaching the target temperature (33-34 °C) or in the first 6 h of TTM. If possible, another ECG was taken after TTM. The patients were being followed until February 2016. Primary endpoint was ventricular arrhythmia during TTM, secondary endpoints were death and hospitalization due to cardiovascular diseases during follow-up. RESULTS: One hundred fifty-eight patients were successfully resuscitated in the study period of which 95 patients had usable data (e.g. ECGs without artifacts). During TTM significant changes for different parameters of ventricular de- and repolarization were noted: QRS (103.2 ± 23.7 vs. 95.3 ± 18.1; p = 0.003),QT (405.8 ± 76.4 vs. 373.8 ± 75.0; p = 0.01), QTc (474.9 ± 59.7 vs. 431.0 ± 56.8; p < 0.001), JT (302.8 ± 69.4 vs. 278.5 ± 75.2; p = 0.043), JTc (354.3 ± 60.2 vs. 318.7 ± 59.1; p = 0.001). 13.7% of the patients had ventricular arrhythmias during TTM, however these patients showed no difference regarding their ECG parameters in comparison to those were no ventricular arrhythmias occurred. We were able to follow 69 Patients over an average period of 35 ± 31 months. The 14 (21.5%) patients who died during the follow-up had significant prolongations of the TpTe-time in the ECGs without TTM (103.9 ± 47.2 vs. 75.8 ± 28.6; p = 0.023). CONCLUSION: Our results show a significant prolongation of ventricular repolarization during TH. However, there was no significant difference between the ECG parameters of those who developed a ventricular arrhythmia and those who did not. The temporary prolongation of the repolarization during TTM seems to be less important for the prognosis of the patient. Whereas the prolongation of the repolarization in the basal ECG is associated with a higher mortality in our study.


Assuntos
Arritmias Cardíacas/epidemiologia , Parada Cardíaca/terapia , Hipotermia Induzida , Adulto , Idoso , Arritmias Cardíacas/diagnóstico , Eletrocardiografia , Feminino , Parada Cardíaca/mortalidade , Parada Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos
5.
Eur J Endocrinol ; 175(5): 467-76, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27562401

RESUMO

INTRODUCTION: Gastrin has been shown to promote beta-cell proliferation in rodents, but its effects in adult humans are largely unclear. Proton pump inhibitors (PPIs) lead to endogenous hypergastrinaemia, and improved glucose control during PPI therapy has been reported in patients with diabetes. Therefore, we addressed whether PPI treatment is associated with improved glucose homoeostasis, islet cell hyperplasia or increased new beta-cell formation in humans. PATIENTS AND METHODS: Pancreatic tissue specimens from 60 patients with and 33 patients without previous PPI therapy were examined. The group was subdivided into patients without diabetes (n = 27), pre-diabetic patients (n = 31) and patients with diabetes (n = 35). RESULTS: Fasting glucose and HbA1c levels were not different between patients with and without PPI therapy (P = 0.34 and P = 0.30 respectively). Beta-cell area was higher in patients without diabetes than in patients with pre-diabetes or diabetes (1.33 ± 0.12%, 1.05 ± 0.09% and 0.66 ± 0.07% respectively; P < 0.0001). There was no difference in beta-cell area between patients with and without PPI treatment (1.05 ± 0.08% vs 0.87 ± 0.08%, respectively; P = 0.16). Beta-cell replication was rare and not different between patients with and without PPI therapy (P = 0.20). PPI treatment was not associated with increased duct-cell replication (P = 0.18), insulin expression in ducts (P = 0.28) or beta-cell size (P = 0.63). CONCLUSIONS: These results suggest that in adult humans, chronic PPI treatment does not enhance beta-cell mass or beta-cell function to a relevant extent.


Assuntos
Glicemia/metabolismo , Proliferação de Células/efeitos dos fármacos , Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Estado Pré-Diabético/metabolismo , Inibidores da Bomba de Prótons/farmacologia , Adulto , Idoso , Tamanho Celular/efeitos dos fármacos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Humanos , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Pâncreas/citologia , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Estado Pré-Diabético/tratamento farmacológico , Inibidores da Bomba de Prótons/uso terapêutico
6.
Metabolism ; 65(3): 84-91, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26892519

RESUMO

INTRODUCTION: The gastrointestinal hormone GLP-1 is released from enteroendocrine L-cells and augments postprandial insulin secretion. In patients with type 2 diabetes, the incretin effect is markedly diminished. It is unclear, whether this is due to a reduction in the abundance of L-cells in the intestine. METHODS: Ileal tissue samples from 10 patients with and 10 patients without diabetes that underwent surgery for the removal of colon tumors were included. Tissue sections were stained for GLP-1, Ki67, TUNEL and chromogranin A. RESULTS: The number of L-cells was not different between patients with and without diabetes in either crypts (1.81±0.21% vs. 1.49±0.24%, respectively; p=0.31) or villi (1.07±0.16% vs. 0.83±0.10%, respectively; p=0.23). L-cell number was higher in crypts than in villi (p<0.0001). L-cell replication was detected rarely and not different between the groups. L-cell apoptosis was similar in patients with and without diabetes in both crypts (7.84±2.77% vs. 8.65±3.77%, p=0.85) and villi (4.48±2.89% vs. 8.62±4.64%, p=0.42). Chromogranin A staining was found in a subset of L-cells only. CONCLUSIONS: Intestinal L-cell density is higher in crypts than in villi. Chromogranin A is not a prerequisite for GLP-1 production. L-cell density and turnover are not different between patients with and without diabetes. Thus, alterations in the number of GLP-1 producing cells do not explain the reduced incretin effect in patients with type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Células Enteroendócrinas/metabolismo , Peptídeo 1 Semelhante ao Glucagon/biossíntese , Íleo/metabolismo , Mucosa Intestinal/metabolismo , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Contagem de Células , Cromogranina A/análise , Cromogranina A/metabolismo , Feminino , Humanos , Íleo/citologia , Mucosa Intestinal/citologia , Antígeno Ki-67 , Masculino , Pessoa de Meia-Idade
7.
Diabetologia ; 58(6): 1175-82, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25725624

RESUMO

AIMS/HYPOTHESIS: Type 2 diabetes has been associated with upper gastrointestinal motility dysfunction, but the relationship with diabetes duration and glucose control is less well understood. Gastric emptying, oesophageal motility and gastrointestinal symptoms were examined in volunteers with diabetes, prediabetes (impaired fasting glucose [IFG] or impaired glucose tolerance [IGT]) and normal glucose tolerance (NGT). METHODS: The study included 41 patients with type 2 diabetes, 17 individuals with IFG/IGT and 31 individuals with NGT. A gastric emptying breath test and high-resolution oesophageal manometry were performed. Gastrointestinal symptoms were assessed using questionnaires. RESULTS: Gastric emptying was delayed in individuals with IFG/IGT (p < 0.05) but was normal in the diabetic group. Amongst the diabetic patients, gastric emptying rate was fastest in those with longer diabetes duration and the highest HbA1c levels (p < 0.001). Oesophageal motility variables were similar between the groups. However, the lower oesophagus resting pressure was reduced in patients with longer diabetes duration (p = 0.01). Abdominal pain/discomfort was more frequent amongst patients with diabetes (p = 0.04) but was unrelated to gastric emptying. Significant associations between various oesophageal motility variables and gastrointestinal symptoms were observed. CONCLUSIONS/INTERPRETATION: Gastric emptying and oesophageal motility are not generally altered in patients with type 2 diabetes. In more advanced disease stages, however, gastric emptying and oesophageal motility may be disturbed, probably as a consequence of autonomic neuropathy. Delayed gastric emptying in IFG/IGT individuals might be secondary to acute hyperglycaemia. Determination of gastric emptying and oesophageal manometry should be considered for the diagnostic workup of patients with diabetes and gastrointestinal symptoms.


Assuntos
Glicemia/análise , Diabetes Mellitus Tipo 2/fisiopatologia , Esvaziamento Gástrico , Motilidade Gastrointestinal , Teste de Tolerância a Glucose , Estado Pré-Diabético/fisiopatologia , Administração Oral , Idoso , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/tratamento farmacológico , Esôfago/fisiologia , Feminino , Humanos , Hiperglicemia/sangue , Hipoglicemiantes/uso terapêutico , Masculino , Manometria , Pessoa de Meia-Idade , Período Pós-Prandial , Estudos Prospectivos , Inquéritos e Questionários
8.
Dtsch Arztebl Int ; 109(26): 466-74, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22833757

RESUMO

BACKGROUND: Type 2 diabetes is common in hospitalized patients and is often accompanied by comorbidities; it is thus reasonable to ask whether the current standard treatments for type 2 diabetes are suitable for in-hospital use. We discuss the current glucose-lowering strategies and glycemic targets and derive practical recommendations for their application in hospitalized patients. METHODS: The pertinent literature, including clinical trials, review articles, guidelines, and manufacturers' information is selectively reviewed. RESULTS: In critically ill patients with diabetes, the glucose concentration target value should be 140 to 180 mg/dL. In stable patients, the target should be less than 140 mg/dL in the fasting state and less than 180 mg/dL after meals. Hypoglycemic episodes should be strictly avoided. Temporary treatment with insulin is indicated for most hospitalized patients with diabetes, although oral antidiabetic agents may be continued if the hospitalization is expected to be brief. Intravenous insulin is advisable in certain situations, e.g., long operations or metabolic decompensation. Glucose-lowering strategies must be chosen individually for each patient, with consideration of the relevant comorbidities (e.g. coronary heart disease, congestive heart failure, cirrhosis, renal failure) and special conditions (e.g. prolonged fasting, administration of contrast agents, high-dose glucocorticoid treatment). CONCLUSION: The treatment of patients with type 2 diabetes in the hospital is very different from their treatment at home. The particular conditions and comorbidities that can arise in the hospital necessitate flexible, individualized strategies for lowering blood glucose concentration.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Hospitalização/estatística & dados numéricos , Hipoglicemiantes/uso terapêutico , Pacientes Internados/estatística & dados numéricos , Humanos , Prevalência , Ensaios Clínicos Controlados Aleatórios como Assunto , Autocuidado , Resultado do Tratamento
9.
Metabolism ; 61(5): 620-4, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22079939

RESUMO

Glucose homeostasis is significantly altered immediately after partial pancreatectomy. The present study examined the long-term consequences of a hemipancreatectomy in 10 patients with chronic pancreatitis and 10 patients with benign pancreatic and extrapancreatic tumors. A 240-minute oral glucose challenge was performed before and shortly after pancreatic surgery, as well as after a follow-up of 3.1 ± 0.5 years. Plasma concentrations of glucose, insulin, and C-peptide were determined; and indices of insulin sensitivity and insulin secretion were calculated. In both groups of patients, fasting and postchallenge glucose concentrations were significantly altered immediately after surgery, but returned to preoperative levels at the time of follow-up (P < .0001). Postchallenge insulin and C-peptide concentrations were reduced immediately after surgery (P < .0001), but were partly normalized at the time of follow-up (P < .0001). These changes were not accompanied by improvements in insulin sensitivity (Matsuda index). However, the oral disposition index revealed a significant recovery of ß-cell function at the time of follow-up (P < .05). These findings demonstrate a capacity for recovery of glucose control after partial pancreatectomy and suggest that ß-cell function can improve significantly over time even in adult humans.


Assuntos
Células Secretoras de Insulina/fisiologia , Pancreatectomia , Glicemia/análise , Peptídeo C/sangue , Diabetes Mellitus/patologia , Feminino , Seguimentos , Teste de Tolerância a Glucose , Humanos , Insulina/sangue , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Pancreatite Crônica/patologia , Pancreatite Crônica/cirurgia , Recuperação de Função Fisiológica
10.
Eur J Endocrinol ; 163(4): 551-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20679359

RESUMO

INTRODUCTION: Hyperproinsulinaemia has been reported in patients with type 2 diabetes. It is unclear whether this is due to an intrinsic defect in ß-cell function or secondary to the increased demand on the ß-cells. We investigated whether hyperproinsulinaemia is also present in patients with secondary diabetes, and whether proinsulin levels are associated with impaired ß-cell area or function. PATIENTS AND METHODS: Thirty-three patients with and without diabetes secondary to pancreatic diseases were studied prior to pancreatic surgery. Intact and total proinsulin levels were compared with the pancreatic ß-cell area and measures of insulin secretion and action. RESULTS: Fasting concentrations of total and intact proinsulin were similar in patients with normal, impaired (including two cases of impaired fasting glucose) and diabetic glucose tolerance (P=0.58 and P=0.98 respectively). There were no differences in the total proinsulin/insulin or intact proinsulin/insulin ratio between the groups (P=0.23 and P=0.71 respectively). There was a weak inverse association between the total proinsulin/insulin ratio and pancreatic ß-cell area (r(2)=0.14, P=0.032), whereas the intact proinsulin/insulin ratio and the intact and total proinsulin levels were unrelated to ß-cell area. However, a strong inverse relationship between homeostasis model assessment index of ß-cell function and both the total and the intact proinsulin/insulin ratio was found (r(2)=0.55 and r(2)=0.48 respectively). The association of insulin resistance (IR) with intact proinsulin was much weaker than the correlation with fasting insulin. CONCLUSIONS: Hyperproinsulinaemia is associated with defects in insulin secretion rather than a reduction in ß-cell area. The weak association between intact proinsulin and IR argues against the usefulness of this parameter in clinical practice.


Assuntos
Diabetes Mellitus/sangue , Diabetes Mellitus/metabolismo , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Insulina/sangue , Insulina/metabolismo , Proinsulina/sangue , Glicemia/metabolismo , Diabetes Mellitus/patologia , Feminino , Humanos , Resistência à Insulina/fisiologia , Secreção de Insulina , Masculino , Pancreatopatias/sangue , Pancreatopatias/metabolismo , Pancreatopatias/patologia
11.
Diabetes ; 58(7): 1595-603, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19509022

RESUMO

OBJECTIVE: beta-Cell mass declines progressively during the course of diabetes, and various antidiabetic treatment regimens have been suggested to modulate beta-cell mass. However, imaging methods allowing the monitoring of changes in beta-cell mass in vivo have not yet become available. We address whether pancreatic beta-cell area can be assessed by functional test of insulin secretion in humans. RESEARCH DESIGN AND METHODS: A total of 33 patients with chronic pancreatitis (n = 17), benign pancreatic adenomas (n = 13), and tumors of the ampulla of Vater (n = 3) at various stages of glucose tolerance were examined with an oral glucose load before undergoing pancreatic surgery. Indexes of insulin secretion were calculated and compared with the fractional beta-cell area of the pancreas. RESULTS: beta-Cell area was related to fasting glucose concentrations in an inverse linear fashion (r = -0.53, P = 0.0014) and to 120-min postchallenge glycemia in an inverse exponential fashion (r = -0.89). beta-Cell area was best predicted by a C-peptide-to-glucose ratio determined 15 min after the glucose drink (r = 0.72, P < 0.0001). However, a fasting C-peptide-to-glucose ratio already yielded a reasonably close correlation (r = 0.63, P < 0.0001). Homeostasis model assessment (HOMA) beta-cell function was unrelated to beta-cell area. CONCLUSIONS: Glucose control is closely related to pancreatic beta-cell area in humans. A C-peptide-to-glucose ratio after oral glucose ingestion appears to better predict beta-cell area than fasting measures, such as the HOMA index.


Assuntos
Adenoma/patologia , Células Secretoras de Insulina/fisiologia , Neoplasias Pancreáticas/patologia , Pancreatite Crônica/patologia , Adenoma/sangue , Adenoma/cirurgia , Glicemia/metabolismo , Peptídeo C/sangue , Diabetes Mellitus/sangue , Diabetes Mellitus/patologia , Jejum , Feminino , Células Ciliadas da Ampola/patologia , Humanos , Insulina/sangue , Células Secretoras de Insulina/citologia , Células Secretoras de Insulina/patologia , Masculino , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/cirurgia , Pancreatite Crônica/sangue , Pancreatite Crônica/cirurgia
12.
J Clin Endocrinol Metab ; 94(8): 2857-63, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19491219

RESUMO

INTRODUCTION: The glucose-induced decline in glucagon levels is often lost in patients with type 2 diabetes. It is unclear whether this is due to an independent defect in alpha-cell function or secondary to the impairment in insulin secretion. We examined whether a partial pancreatectomy in humans would also impair postchallenge glucagon concentrations and, if so, whether this could be attributed to the reduction in insulin levels. PATIENTS AND METHODS: Thirty-six patients with pancreatic tumours or chronic pancreatitis were studied before and after approximately 50% pancreatectomy with a 240-min oral glucose challenge, and the plasma concentrations of glucose, insulin, C-peptide, and glucagon were determined. RESULTS: Fasting and postchallenge insulin and C-peptide levels were significantly lower after partial pancreatectomy (P < 0.0001). Likewise, fasting glucagon concentrations tended to be lower after the intervention (P = 0.11). Oral glucose ingestion elicited a decline in glucagon concentrations before surgery (P < 0.0001), but this was lost after partial pancreatectomy (P < 0.01 vs. preoperative values). The loss of glucose-induced glucagon suppression was found after both pancreatic head (P < 0.001) and tail (P < 0.05) resection. The glucose-induced changes in glucagon levels were closely correlated to the respective increments in insulin and C-peptide concentrations (P < 0.01). CONCLUSIONS: The glucose-induced suppression in glucagon levels is lost after a 50% partial pancreatectomy in humans. This suggests that impaired alpha-cell function in patients with type 2 diabetes may also be secondary to reduced beta-cell mass. Alterations in glucagon regulation should be considered as a potential side effect of partial pancreatectomies.


Assuntos
Glucagon/sangue , Glucose/farmacologia , Pancreatectomia , Adulto , Idoso , Glicemia/análise , Peptídeo C/análise , Feminino , Células Secretoras de Glucagon/fisiologia , Humanos , Insulina/metabolismo , Secreção de Insulina , Células Secretoras de Insulina/patologia , Masculino , Pessoa de Meia-Idade
13.
J AOAC Int ; 80(5): 988-95, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9325577

RESUMO

A bulk portion of homogenized pig liver tissue was spiked at room temperature with 0.2 mg/kg (twice the Australian maximum residue limit) of each of sulfathiazole, sulfachlorpyridazine, sulfadimidine (sulfamethazine), sulfaquinoxaline, and sulfadimethoxine. After subsampling and packaging, selected individual packaged units were tested to confirm homogeneity of the prepared material. The material was stored frozen at -20 degrees C and analyzed in replicate by liquid chromatography on 11 sampling dates over a period of about 6 months. Analytical data were plotted on a log-linear scale and subjected to linear regression on the basis of first-order kinetics for the decay. Storage stabilities (decay half-lives at -20 degrees C) calculated from the mean slope of regression lines were sulfadimethoxine, 567 days; sulfadimidine, 457 days; sulfachlorpyridazine, 312 days; sulfathiazole, 291 days; and sulfaquinoxaline, 271 days. Significant depletion (65% loss) of residue was observed for sulfaquinoxaline during preparation of spiked bulk liver tissue. An extension of the study to measure the storage stability of sulfaquinoxaline under accelerated decay conditions (refrigerator temperature, 4 degrees C) showed it to be relatively unstable, with a decay half-life of 11 days. Results demonstrate the need for both regulatory agencies and testing laboratories to be aware of potential errors associated with improper transport, storage, and handling of tissue samples submitted for antibiotic testing.


Assuntos
Anti-Infecciosos/química , Criopreservação , Fígado/química , Sulfonamidas/química , Análise de Variância , Animais , Estabilidade de Medicamentos , Meia-Vida , Controle de Qualidade , Sulfacloropiridazina/química , Sulfadimetoxina/química , Sulfametazina/química , Sulfaquinoxalina/química , Sulfatiazol , Sulfatiazóis/química , Suínos
17.
Arch Otolaryngol ; 101(11): 689-92, 1975 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1106377

RESUMO

Subglottic stenosis in the infant currently has no well-accepted surgical correction. Our experimental study was designed to determine the effectiveness of a nasal septal cartilage-mucosa autograft in increasing the subglottic circumference and its effect on subsequent subglottic growth. Six pairs of matched mongrel puppy litter mates were used; one underwent surgery, the other served as a control. The cricoid and first tracheal rings were split anteriorly, and widened 5 mm to accept an autogenous nasal septal cartilage-mucosa graft. All animals were killed after six months of postoperative growth. The autografts appeared to be partially or completely replaced by fibrous tissue but a persistent enlargement in the subglottic airway was found in the animals that underwent surgery, with glottic measurements the same in both groups. Thus, a septal cartilage autograft to the subglottic larynx in puppies appears to result in persistent enlargement of the subglottic area, but produces no interference with subsequent normal laryngeal growth and development.


Assuntos
Cartilagem/transplante , Glote/cirurgia , Doenças da Laringe/cirurgia , Transplante de Pele , Transplante Autólogo/métodos , Animais , Cães , Humanos , Lactente
18.
Arch Otolaryngol ; 101(4): 217-21, 1975 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1120009

RESUMO

This experimental pilot project studies acute laryngeal injuries in 20 dogs and compares the use of three types of stenting materials with using no stent at all following the production of a "controlled airway deforming injury." Each injury was repaired meticulously using stainless steel wire to immobilize the cartilage separations, and fine catgut to close the mucosal lacerations. Animals were killed after observation for periods of two to six weeks postoperatively. Marked infection, ulceration, and granulation tissue formation were observed in most of the stented animals, with the nonstented animals showing the most complete and uncomplicated healing. In this experimental model, acute laryngeal "fractures" were adequately stabilized by suturing and a stable cartilaginous framework supported the healing intralaryngeal soft tissues. Avoidance of stenting in this animal series appears to decrease infection, ulceration, and granulation tissue formation resulting in improved healing.


Assuntos
Laringe/lesões , Equipamentos Cirúrgicos , Doença Aguda , Animais , Cães , Tecido de Granulação , Infecções/etiologia , Cartilagens Laríngeas/lesões , Mucosa , Projetos Piloto , Politetrafluoretileno , Fenômenos Fisiológicos Respiratórios , Borracha , Elastômeros de Silicone , Aço Inoxidável , Úlcera/etiologia , Ferimentos e Lesões/terapia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...