Luxaciones periastragalinas: análisis de una serie de casos. Nuestro algoritmo de tratamiento urgente / Subtalar dislocations: Analysis of a case series. Our urgent treatment algorithm

Introducción y objetivos: Las luxaciones periastragalinas son una entidad poco frecuente (<1%) de las lesiones traumáticas del pie. Se produce una pérdida de relación anatómica entre astrágalo, calcáneo y escafoides. Solo hay pequeñas series publicadas. Material y métodos: Presentamos los casos de una serie de pacientes (N=13) con luxaciones periastragalinas en los que se realizó un análisis descriptivo de las principales variables epidemiológicas, clínicas y radiológicas, a partir de las cuales se propone un algoritmo de tratamiento urgente. Se excluyeron los casos con fracturas del cuello del astrágalo, cuerpo del calcáneo o fracturas-luxación de Chopart aisladas. Resultados: La mediana de edad fue de 48,5 años con predominio del sexo masculino (69,23%). Cinco pacientes sufrieron caídas-entorsis sobre el tobillo y los 8 restantes mecanismos de alta energía. Las luxaciones mediales (9) predominaron sobre las laterales (4). Además, 4 pacientes presentaron luxaciones abiertas, 2 de ellas tipo IIIC que precisaron amputación. Se solicitó TC en un 76,93% de pacientes y 10 presentaron lesiones óseas asociadas del pie. Se realizó cirugía mediante reducción abierta en todas las lesiones abiertas y en un caso en el que fracasó la reducción cerrada. Cinco pacientes precisaron fijador externo tipo delta. Se objetivó esclerosis subcondral articular en un 77,77% de los casos; si bien solo uno precisó artrodesis subtalar. Conclusiones: Las luxaciones periastragalinas son una urgencia traumatológica y precisan una reducción precoz e inmovilización posterior. La fijación externa temporal transarticular es una buena opción de inmovilización en luxaciones abiertas. Son lesiones graves con alta probabilidad de artrosis precoz.(AU)

Introduction and objectives: Subtalar dislocations are a rare entity (<1%) in traumatic foot injuries. There is a loss of anatomical relationship between the talus, calcaneus and scaphoid. There are only small-published series. Material and methods: We present a series of patients (N=13) with subtalar dislocations in which a descriptive analysis of the main epidemiological, clinical and radiological variables was carried out, from which an urgent treatment algorithm is proposed. Cases with fractures of the neck of the talus, body of the calcaneus, or isolated Chopart fracture-dislocations were excluded. Results: The median age was 48.5 years with a predominance of males (69.23%). Five patients suffered falls or sprained ankles and the other eight suffered high-energy mechanisms. The medial dislocations (nine) predominated over the lateral ones (four). In addition, four patients presented open dislocations, two of them type IIIC that required amputation. CT scans were requested in 76.93% of patients and 10 presented associated bone lesions of the foot. Open reduction surgery was performed in all open lesions and in one case in which closed reduction failed. Five patients required a delta-type external fixator. Subchondral articular sclerosis was observed in 77.77% of cases; although only one required subtalar arthrodesis. Conclusions: Subtalar dislocations are a traumatic emergency that require early reduction and subsequent immobilization. Transarticular temporary external fixation is a good immobilization option in open dislocations. They are serious lesions with a high probability of early osteoarthritis.(AU)

[Translated article] Subtalar dislocations: Analysis of a case series. Our urgent treatment algorithm / Luxaciones periastragalinas: análisis de una serie de casos. Nuestro algoritmo de tratamiento urgente

Introducción y objetivos: Las luxaciones periastragalinas son una entidad poco frecuente (<1%) de las lesiones traumáticas del pie. Se produce una pérdida de relación anatómica entre astrágalo, calcáneo y escafoides. Solo hay pequeñas series publicadas. Material y métodos: Presentamos los casos de una serie de pacientes (N=13) con luxaciones periastragalinas en los que se realizó un análisis descriptivo de las principales variables epidemiológicas, clínicas y radiológicas, a partir de las cuales se propone un algoritmo de tratamiento urgente. Se excluyeron los casos con fracturas del cuello del astrágalo, cuerpo del calcáneo o fracturas-luxación de Chopart aisladas. Resultados: La mediana de edad fue de 48,5 años con predominio del sexo masculino (69,23%). Cinco pacientes sufrieron caídas-entorsis sobre el tobillo y los 8 restantes mecanismos de alta energía. Las luxaciones mediales (9) predominaron sobre las laterales (4). Además, 4 pacientes presentaron luxaciones abiertas, 2 de ellas tipo IIIC que precisaron amputación. Se solicitó TC en un 76,93% de pacientes y 10 presentaron lesiones óseas asociadas del pie. Se realizó cirugía mediante reducción abierta en todas las lesiones abiertas y en un caso en el que fracasó la reducción cerrada. Cinco pacientes precisaron fijador externo tipo delta. Se objetivó esclerosis subcondral articular en un 77,77% de los casos; si bien solo uno precisó artrodesis subtalar. Conclusiones: Las luxaciones periastragalinas son una urgencia traumatológica y precisan una reducción precoz e inmovilización posterior. La fijación externa temporal transarticular es una buena opción de inmovilización en luxaciones abiertas. Son lesiones graves con alta probabilidad de artrosis precoz.(AU)

Introduction and objectives: Subtalar dislocations are a rare entity (<1%) in traumatic foot injuries. There is a loss of anatomical relationship between the talus, calcaneus and scaphoid. There are only small-published series. Material and methods: We present a series of patients (N=13) with subtalar dislocations in which a descriptive analysis of the main epidemiological, clinical and radiological variables was carried out, from which an urgent treatment algorithm is proposed. Cases with fractures of the neck of the talus, body of the calcaneus, or isolated Chopart fracture-dislocations were excluded. Results: The median age was 48.5 years with a predominance of males (69.23%). Five patients suffered falls or sprained ankles and the other eight suffered high-energy mechanisms. The medial dislocations (nine) predominated over the lateral ones (four). In addition, four patients presented open dislocations, two of them type IIIC that required amputation. CT scans were requested in 76.93% of patients and 10 presented associated bone lesions of the foot. Open reduction surgery was performed in all open lesions and in one case in which closed reduction failed. Five patients required a delta-type external fixator. Subchondral articular sclerosis was observed in 77.77% of cases; although only one required subtalar arthrodesis. Conclusions: Subtalar dislocations are a traumatic emergency that require early reduction and subsequent immobilization. Transarticular temporary external fixation is a good immobilization option in open dislocations. They are serious lesions with a high probability of early osteoarthritis.(AU)

[Translated article] SCIWORA in children. A rare clinical entity: Ambispective study / SCIWORA. Una rara entidad clínica en la población pediátrica. Estudio ambispectivo

Introducción y objetivos: Las luxaciones periastragalinas son una entidad poco frecuente (<1%) de las lesiones traumáticas del pie. Se produce una pérdida de relación anatómica entre astrágalo, calcáneo y escafoides. Solo hay pequeñas series publicadas. Material y métodos: Presentamos los casos de una serie de pacientes (N=13) con luxaciones periastragalinas en los que se realizó un análisis descriptivo de las principales variables epidemiológicas, clínicas y radiológicas, a partir de las cuales se propone un algoritmo de tratamiento urgente. Se excluyeron los casos con fracturas del cuello del astrágalo, cuerpo del calcáneo o fracturas-luxación de Chopart aisladas. Resultados: La mediana de edad fue de 48,5 años con predominio del sexo masculino (69,23%). Cinco pacientes sufrieron caídas-entorsis sobre el tobillo y los 8 restantes mecanismos de alta energía. Las luxaciones mediales (9) predominaron sobre las laterales (4). Además, 4 pacientes presentaron luxaciones abiertas, 2 de ellas tipo IIIC que precisaron amputación. Se solicitó TC en un 76,93% de pacientes y 10 presentaron lesiones óseas asociadas del pie. Se realizó cirugía mediante reducción abierta en todas las lesiones abiertas y en un caso en el que fracasó la reducción cerrada. Cinco pacientes precisaron fijador externo tipo delta. Se objetivó esclerosis subcondral articular en un 77,77% de los casos; si bien solo uno precisó artrodesis subtalar. Conclusiones: Las luxaciones periastragalinas son una urgencia traumatológica y precisan una reducción precoz e inmovilización posterior. La fijación externa temporal transarticular es una buena opción de inmovilización en luxaciones abiertas. Son lesiones graves con alta probabilidad de artrosis precoz.(AU)

Introduction and objectives: Subtalar dislocations are a rare entity (<1%) in traumatic foot injuries. There is a loss of anatomical relationship between the talus, calcaneus and scaphoid. There are only small-published series. Material and methods: We present a series of patients (N=13) with subtalar dislocations in which a descriptive analysis of the main epidemiological, clinical and radiological variables was carried out, from which an urgent treatment algorithm is proposed. Cases with fractures of the neck of the talus, body of the calcaneus, or isolated Chopart fracture-dislocations were excluded. Results: The median age was 48.5 years with a predominance of males (69.23%). Five patients suffered falls or sprained ankles and the other eight suffered high-energy mechanisms. The medial dislocations (nine) predominated over the lateral ones (four). In addition, four patients presented open dislocations, two of them type IIIC that required amputation. CT scans were requested in 76.93% of patients and 10 presented associated bone lesions of the foot. Open reduction surgery was performed in all open lesions and in one case in which closed reduction failed. Five patients required a delta-type external fixator. Subchondral articular sclerosis was observed in 77.77% of cases; although only one required subtalar arthrodesis. Conclusions: Subtalar dislocations are a traumatic emergency that require early reduction and subsequent immobilization. Transarticular temporary external fixation is a good immobilization option in open dislocations. They are serious lesions with a high probability of early osteoarthritis.(AU)

Subtalar dislocations: Analysis of a case series. Our urgent treatment algorithm. / Luxaciones periastragalinas: análisis de una serie de casos. Nuestro algoritmo de tratamiento urgente.

INTRODUCTION AND OBJECTIVES: Subtalar dislocations are a rare entity (<1%) in traumatic foot injuries. There is a loss of anatomical relationship between the talus, calcaneus and scaphoid. There are only small-published series. MATERIAL AND METHODS: We present a series of patients (N=13) with subtalar dislocations in which a descriptive analysis of the main epidemiological, clinical and radiological variables was carried out, from which an urgent treatment algorithm is proposed. Cases with fractures of the neck of the talus, body of the calcaneus, or isolated Chopart fracture-dislocations were excluded. RESULTS: The median age was 48.5 years with a predominance of males (69.23%). Five patients suffered falls or sprained ankles and the other eight suffered high-energy mechanisms. The medial dislocations (nine) predominated over the lateral ones (four). In addition, four patients presented open dislocations, two of them type IIIC that required amputation. CT scans were requested in 76.93% of patients and 10 presented associated bone lesions of the foot. Open reduction surgery was performed in all open lesions and in one case in which closed reduction failed. Five patients required a delta-type external fixator. Subchondral articular sclerosis was observed in 77.77% of cases; although only one required subtalar arthrodesis. CONCLUSIONS: Subtalar dislocations are a traumatic emergency that require early reduction and subsequent immobilization. Transarticular temporary external fixation is a good immobilization option in open dislocations. They are serious lesions with a high probability of early osteoarthritis.

[Translated article] Subtalar dislocations: Analysis of a case series. Our urgent treatment algorithm.

INTRODUCTION AND OBJECTIVES: Subtalar dislocations are a rare entity (<1%) in traumatic foot injuries. There is a loss of anatomical relationship between the talus, calcaneus and scaphoid. There are only small-published series. MATERIAL AND METHODS: We present a series of patients (N=13) with subtalar dislocations in which a descriptive analysis of the main epidemiological, clinical and radiological variables was carried out, from which an urgent treatment algorithm is proposed. Cases with fractures of the neck of the talus, body of the calcaneus, or isolated Chopart fracture-dislocations were excluded. RESULTS: The median age was 48.5 years with a predominance of males (69.23%). Five patients suffered falls or sprained ankles and the other eight suffered high-energy mechanisms. The medial dislocations (nine) predominated over the lateral ones (four). In addition, four patients presented open dislocations, two of them type IIIC that required amputation. CT scans were requested in 76.93% of patients and 10 presented associated bone lesions of the foot. Open reduction surgery was performed in all open lesions and in one case in which closed reduction failed. Five patients required a delta-type external fixator. Subchondral articular sclerosis was observed in 77.77% of cases; although only one required subtalar arthrodesis. CONCLUSIONS: Subtalar dislocations are a traumatic emergency that require early reduction and subsequent immobilisation. Transarticular temporary external fixation is a good immobilisation option in open dislocations. They are serious lesions with a high probability of early osteoarthritis.

Diagnosis, treatment and outcome of cranial nuchal bursitis in 30 horses.

BACKGROUND: No large retrospective case series describing the treatment and outcomes following diagnosis of cranial nuchal bursitis have been published. OBJECTIVE: To describe the clinical presentation, diagnostic techniques, treatment and outcome of horses suffering from cranial nuchal bursitis and to determine their outcome after medical or surgical treatment. STUDY DESIGN: Retrospective case series. METHODS: Medical records (1990-2014) of two referral centres were reviewed for signalment, diagnostic features, method of treatment (medical, surgical or both) and outcome. RESULTS: The median age of horses was 13 years (range 5-22 years) and follow-up time ranged from 12 to 108 months. Fourteen horses were treated medically and 20 horses were treated surgically. Of those horses treated medically, four horses had recurrence of clinical signs requiring subsequent surgical treatment. Overall, 41.7% of horses had recurrence of clinical signs following treatment and 66.7% of horses were able to return to their previous level of exercise. Five horses underwent more than one surgical procedure due to recurrence of clinical signs. Of those horses treated solely surgically, 28.6% of the horses had recurrence of clinical signs and 78.6% returned to their previous level of exercise. Of those horses treated solely medically, 33.3% had recurrence of clinical signs and 66.7% returned to their previous level of exercise. Of those horses treated surgically following failed medical management, 100% had recurrence of clinical signs and 25% returned to their previous level of exercise. MAIN LIMITATIONS: Retrospective design with small sample number. CONCLUSIONS: Nuchal bursitis can be successfully managed with either medical or surgical treatment. Prognosis for return to work tends to be worse in horses requiring surgical intervention following failed medical management.

The cranial nuchal bursa: anatomy, ultrasonography, magnetic resonance imaging and endoscopic approach.

REASONS FOR PERFORMING STUDY: Although an uncommon condition, cranial nuchal bursitis can affect the performance of the equine athlete. The anatomy is not well described and there are no reports of diagnostic imaging for endoscopic approaches. OBJECTIVES: To describe the anatomy, ultrasonographic and magnetic resonance features of and endoscopic approach to the cranial nuchal bursa in horses. STUDY DESIGN: Experimental cadaver study. METHODS: Four cranial nuchal bursae were dissected, 4 specimens were frozen to prepare anatomical sections and 2 were injected with latex to document surface landmarks and topographical anatomy and to identify the possible sites for endoscopic access. Six cadaveric specimens were used to describe the ultrasonographic and magnetic resonance features of the cranial nuchal bursa before and after intrabursal injection. Sixteen cadaver specimens were evaluated with a rigid arthroscope and gross dissection to determine the endoscopic appearance of the bursa. RESULTS: The cranial nuchal bursa could be identified consistently in all cadavers, using ultrasonographic and magnetic resonance on both pre- and post injection specimens. Cranial and caudal endoscopic approaches and instrument portals were developed for the cranial nuchal bursa. Using either approach, the entire extent of the bursa could be evaluated, but separate approaches for left and right compartments of the bursa were needed owing to the lack of manoeuvrability when examining the contralateral compartment. CONCLUSIONS: The cranial nuchal bursa can be identified on ultrasonographic and magnetic resonance images. An endoscopic approach to the cranial nuchal bursa is clinically feasible and offered an easy, repeatable entry into the cranial nuchal bursa, which allowed adequate observation of the structures within the bursa. This may be of help for diagnosis and treatment of conditions affecting the cranial nuchal bursa in horses.

Surgical treatment of distal tarsal joint luxations in three horses.

The clinical signs, radiographic findings, surgical treatment, and outcome of three horses with luxation of the distal tarsal joints are reported. Two patients showed luxations of the tarsometatarsal joint whereas luxation of the proximal intertarsal joint was found in one case. Open reduction, followed by internal fixation was performed in two horses and closed reduction with a transfixation pin cast was performed in the third. The treatment in all three cases resulted in a satisfactory clinical outcome.

Intrapersonal HbA(1c) variability and the risk of progression of nephropathy in patients with Type 2 diabetes.

AIM: To investigate the association between nephropathy and HbA(1c) variability (assessed as the standard deviation of each patient's HbA(1c) measurements) among patients with Type 2 diabetes. METHODS: Albumin excretion rate and HbA(1c) were measured in 2103 patients followed up for a mean 6.6 years. Multivariate Cox regression analysis was used to determine the influence of HbA(1c) variability on the risk of progression of nephropathy after adjustment for age, sex, duration of diabetes, baseline condition (two cohorts defined by duration of diabetes, retinopathy and albumin excretion rate), baseline HbA(1c) , insulin use, BMI, use of anti-hypertensive agents, smoking, lipid status, retinopathy, updated mean HbA(1c) and number of HbA(1c) measurements. RESULTS: Nephropathy progressed in 18.3% of subjects. HbA(1c) variability was significantly greater among progressors than among non-progressors (12 vs. 10 mmol/mol; 1.12 vs. 0.90%; P < 0.0001) and was a significant predictor of progression of nephropathy even after adjustment for updated mean HbA(1c) and other risk factors (hazard ratio 1.37, 95% CI 1.12-1.69). CONCLUSION: In patients with Type 2 diabetes, the risk of progression of nephropathy increases significantly with HbA(1c) variability, independently of the influence of updated mean HbA(1c) .

In vitro biomechanical evaluation and comparison of a new prototype locking plate and a limited-contact self compression plate for equine fracture repair.

OBJECTIVE: To determine if the mechanical properties (strength and stiffness) of a new prototype 4.5 mm broad locking plate (NP-LP) are comparable with those of a traditional 4.5 mm broad limited-contact self compression plate (LC-SCP), and to compare the bending and torsional properties of the NP-LP and LC-SCP when used in osteotomized equine third metacarpal bones (MC3). METHODS: The plates alone were tested in four-point bending single cycle to failure. The MC3-plate constructs were created with mid-diaphyseal osteotomies with a 1 cm gap. Constructs were tested in four-point bending single cycle to failure, four-point bending cyclic fatigue, and torsion single cycle to failure. RESULTS: There were not any significant differences in bending strength and stiffness found between the two implants. The MC3-NP-LP construct was significantly stiffer than the MC3-LC-SCP in bending. No other biomechanical differences were found in bending, yield load in torsion, or mean composite rigidity. Mean cycles to failure for bending fatigue testing were similar for both constructs. CLINICAL SIGNIFICANCE: The NP-LP was comparable to the LC-SCP in intrinsic, as well as structural properties. The NP-LP construct was more rigid than the LC-SCP construct under four-point bending, and both constructs behaved similarly under four-point bending cyclic fatigue testing and torsion single cycle to failure. The new NP-LP implant fixation is biomechanically comparable to the LC-SCP in a simulated MC3 fracture.

Complete caecal bypass without ileal transection for caecal impaction in horses: seven clinical cases (1997-2007).

OBJECTIVES: To report the clinical outcome in seven horses following use of a newly described surgical technique for treating caecal impaction. METHODS: The medical records of seven horses with caecal impaction treated surgically using a stapling technique to create a complete caecal bypass without ileal transection were reviewed. Data were obtained from the records and through telephone interviews with case-associated personnel. RESULTS: The mean age was 10 years (range 2-22 years) and duration of colic ranged from 24 h to 2 weeks. Five horses had type II motility dysfunction and the remaining two had type I. Mean surgical time was 185 min (range 146-245 min) and the horses were hospitalised for a mean of 12.4 days (range 9-22 days); 71% (5/7) were discharged from hospital and all five were alive 60 days from the surgery date. One horse was lost to follow-up. The four (66.7%) available remaining horses were alive ≥ 1 year (long-term survivors). CONCLUSIONS: Complete caecal bypass without ileal transection for clinical cases of caecal impaction had comparable outcomes to complete bypass with ileal transection. The technique is easy to perform, has the potential to reduce surgical time, compared with traditional bypass techniques, and may reduce the risk of intraoperative abdominal contamination. It is recommended for use in clinical cases in which caecal bypass is desirable.

Surgical repair of coxofemoral luxation in a horse.

A 4-year-old castrated male Miniature Horse was evaluated because of severe right hind limb lameness of 5 days' duration. The diagnosis of craniodorsal luxation of the right coxofemoral joint was made by physical examination and radiographic imaging. Closed reduction was attempted but was unsuccessful. Surgical reduction was successfully performed, using toggle pin, synthetic capsular reconstruction, and trochanteric transposition techniques. No postoperative complications were observed. Follow-up 26 months after surgery revealed no recurrence of the luxation and no evidence of lameness. These surgical techniques are used successfully for repair of coxofemoral luxations in small animals. To our knowledge, there has been no report of these techniques attempted in horses. These surgical techniques may have merit for the treatment of coxofemoral luxations in small equine patients.

Prevalence and prognostic importance of hypomagnesemia and hypocalcemia in horses that have colic surgery.

OBJECTIVE: To determine the prevalence of hypomagnesemia and hypocalcemia in horses with surgical colic. ANIMALS: 35 horses with surgically managed colic. PROCEDURE: Serum concentrations of total magnesium (tMg2+) and calcium (tCa2+), as well as ionized magnesium (iMg2+) and calcium (iCa2+) were analyzed before surgery and 1, 3, 5, and 7 days following surgery. A lead-II ECG and pertinent clinical data were also obtained at each time. RESULTS: Preoperative serum tMg2+ and iMg2+ concentrations were below the reference range in 6 (17%) and 19 (54%) horses, respectively. Serum concentrations of tCa2+ and iCa2+ were less than the reference range in 20 (57%) and 30 (86%) horses before surgery. Horses with strangulating lesions of the gastrointestinal tract had significantly lower preoperative serum concentrations of iMg2+ and iCa2+, as well as a higher heart rate than horses with nonstrangulating lesions. Horses that developed postoperative ileus had significantly lower serum concentrations of iMg2+ after surgery. Serum concentrations of magnesium and calcium (total and ionized) correlated significantly with the PR, QRS, QT, and corrected QT (QTc) intervals. Horses that were euthanatized at the time of surgery (n = 7) had significantly lower preoperative serum concentrations of iMg2+, compared with horses that survived. Neither serum magnesium nor calcium concentrations were predictors of hospitalization time or survival. CONCLUSIONS AND CLINICAL RELEVANCE: Hypomagnesemia and hypocalcemia were common during the perioperative period, particularly in horses with strangulating intestinal lesions and ileus. Serum concentrations of tMg2+ and tCa2+ were less sensitive than iMg2+ and iCa2+ in detecting horses with hypomagnesemia and hypocalcemia.

A cytochemical scanning electron microscopy study of non-specific acid esterase and acid phosphatase activities in human peripheral blood lymphocytes.

We analyzed the distribution patterns of nonspecific acid esterase and acid phosphatase activities with cytochemistry-scanning electron microscopy in backscattered and secondary electron imaging modes in isolated normal human peripheral blood lymphocytes. The analysis of non-specific acid esterase activity in the backscattered electron imaging mode showed, in some cells, focal distribution with a well-defined, homogenous deposit. Two patterns of acid phosphatase activity were evident with the backscattered electron imaging mode, i.e., focal and granular. Peripheral blood lymphocytes showing focal activity of both enzymes presented a smooth surface with few scattered microvilli as seen with the secondary electron imaging mode; while lymphocytes with a granular pattern of acid phosphatase activity had abundant microvilli. The correlation between patterns of enzymatic activity as seen in backscattering electron imaging mode, and surface morphological features as seen with secondary electron imaging mode, distinguished a subpopulation of lymphocytes of T lineage in human peripheral blood.

Insulin sensitivity and metabolic clearance rate of insulin in familial multiple lipomatosis.

Intolerance to glucose in certain kinds of lipomatosis is well documented. This article describes a euglucaemic hyperinsulinaemic clamp study of alterations in glucose and/or insulin metabolism in four members of a single family with familial multiple lipomatosis. Fifteen normal subjects were studied as controls. The four patients exhibited no alteration in tolerance to orally administered glucose. When a Biostator Glucose-Controlled Insulin Infusion System (GCIIS) was used to clamp glycaemia at 4.44 mmol/L with successive insulin infusion rates of (a) 0.5 (b) 1.0 or (c) 5.0 mU/kg/min, there was no difference between patients and controls as regards the value of M, the rate of glucose infusion, but the concentrations of immunoreactive insulin recorded during the last 40 minutes of each phase of the clamp were greater in patients than in controls (45 +/- 2 vs 27 +/- 2 uU/mL (p less than 0.01), 83 +/- 2 vs 60 +/- 5 uU/mL (p less than 0.05) and 537 +/- 48 vs 377 +/- 25 uU/mL (p less than 0.05) for insulin infusion rates (a), (b) and (c) respectively), and the ratio M/IRI was consequently smaller for patients than controls (1.92 +/- 0.41 vs 3.06 +/- 0.19 (p less than 0.05) for an insulin infusion rate of 5 mU/kg/min). The metabolic clearance rate of insulin was likewise slower in patients than controls (p less than 0.01). It is concluded that the four patients studied (all members of the same family) have sub-normal sensitivity to insulin secondary to a sub-normal metabolic clearance rate for insulin.

Beta cell response to the hyperglycaemic clamp in three patients with insulinoma: a study using a hyperglycaemic glucose clamp.

To determine the mechanism responsible for deficient carbohydrate metabolism in patients with insulinoma, we studied three affected patients and seven normal controls using the hyperglycaemic clamp method (8.4 mmol/l) with the BIOSTATOR (GCIIS). In insulinoma patients, the amount of glucose necessary to reach the hyperglycaemic clamp was less than that required in normal controls (6.19 +/- 1.19 mg/min/kg vs. 9.95 +/- 0.53 mg/min/kg) (p less than 0.05). There was no significant difference in metabolized glucose (M) in the stable phase of the hyperglycaemic clamp; however, the M/IRI in this phase was less in those with insulinoma (7.9 +/- 0.50) than in controls (22.26 +/- 4.14) (p less than 0.05). There was no difference in beta cell secretory response to hyperglycaemic stimulus (defined as the increase in the concentration of C-peptide from the basal state to the stable phase of the hyperglycaemic clamp) between the two groups. Hepatic insulin extraction was significantly lower in patients with insulinoma than in normal controls (+0.72 +/- 0.07 vs. +0.85 +/- 0.01). Finally, the ratios of fractional turnover of glucose (K/IRI); glucose clearance/IRI and total rate of elimination of glucose from the extracellular pool/IRI were also all lower in patients with insulinoma than in controls (p less than 0.05). These data support the conclusion that deficient glucose metabolism seen in these patients is not related to a lack of response to glucose on the part of normal or neoplastic islet tissue.(ABSTRACT TRUNCATED AT 250 WORDS)