A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Skeletal findings in the first 12 months following initiation of glucocorticoid therapy for pediatric nephrotic syndrome

Incident vertebral fractures and lumbar spine bone mineral density (BMD) were assessed in the 12 months following glucocorticoid initiation in 65 children with nephrotic syndrome. The incidence of vertebral fractures was low at 12 months (6 %) and most patients demonstrated recovery in BMD Z-scores by this time point.

INTRODUCTION

Vertebral fracture (VF) incidence following glucocorticoid (GC) initiation has not been previously reported in pediatric nephrotic syndrome.

METHODS

VF was assessed on radiographs (Genant method); lumbar spine bone mineral density (LS BMD) was evaluated by dual-energy X-ray absorptiometry.

RESULTS

Sixty-five children were followed to 12 months post-GC initiation (median age, 5.4 years; range, 2.3-17.9). Three of 54 children with radiographs (6 %; 95 % confidence interval (CI), 2-15 %) had incident VF at 1 year. The mean LS BMD Z-score was below the healthy average at baseline (mean ± standard deviation (SD), -0.5 ± 1.1; p = 0.001) and at 3 months (-0.6 ± 1.1; p < 0.001), but not at 6 months (-0.3 ± 1.3; p = 0.066) or 12 months (-0.3 ± 1.2; p = 0.066). Mixed effect modeling showed a significant increase in LS BMD Z-scores between 3 and 12 months (0.22 SD; 95 % CI, 0.08 to 0.36; p = 0.003). A subgroup (N = 16; 25 %) had LS BMD Z-scores that were ≤-1.0 at 12 months. In these children, each additional 1,000 mg/m(2) of GC received in the first 3 months was associated with a decrease in LS BMD Z-score by 0.39 at 12 months (95 % CI, -0.71 to -0.07; p = 0.017).

CONCLUSIONS

The incidence of VF at 1 year was low and LS BMD Z-scores improved by 12 months in the majority. Twenty-five percent of children had LS BMD Z-scores ≤-1.0 at 12 months. In these children, LS BMD Z-scores were inversely associated with early GC exposure, despite similar GC exposure compared to the rest of the cohort.

The development of bone mineral lateralization in the arms

Bone mineral content (BMC) is known to be greater in the dominant arm after the age of 8 years. We studied a group of children and found that BMC sidedness gradually increased up to the age of 6 years and then remained stable into late adolescence.

INTRODUCTION

Bone mineral content (BMC) exhibits sidedness in the arms after the age of 8 years, but it is not known whether BMC is greater in the dominant arm from birth or whether lateralization develops in early childhood. To address this, we examined bone mineral status in relation to handedness and age.

METHODS

Subjects (N = 158) were children recently initiating glucocorticoids for underlying disease (leukemia 43 %, rheumatic conditions 39 %, nephrotic syndrome 18 %). Handedness was determined by questionnaire and BMC by dual-energy X-ray absorptiometry.

RESULTS

Median age was 7.2 years (range, 1.5 to 17.0 years), 49 % was male, and the spine BMD Z-score was -0.9 (SD, 1.3). By linear regression, BMC sidedness in the arms was significantly related to age (r = 0.294, p = 0.0005). Breakpoint analysis revealed two lines with a knot at 6.0 years (95 % CI, 4.5-7.5 years). The formula for the first line was: dominant:nondominant arm BMC ratio = 0.029 × age [in years] + 0.850 (r = 0.323, p = 0.017). The slope of the second line was not different from 0 (p = 0.332), while the slopes for the two lines were significantly different (p = 0.027).

CONCLUSIONS

These results show that arm BMC sidedness in this patient group develops up to age 6 years and then remains stable into late adolescence. This temporal profile is consistent with mechanical stimulation of the skeleton in response to asymmetrical muscle use as handedness becomes manifest.

Can methadone concentrations predict the severity of withdrawal in infants at risk of neonatal abstinence syndrome?

AIM

To assess the usefulness of cord and serum methadone concentrations at 2 days of age in predicting the severity of neonatal abstinence syndrome (NAS) in infants whose mothers received methadone during pregnancy.

METHODS

After informed consent, infants were enrolled if they were delivered at 35 weeks gestation or greater. Relevant information was collected from maternal notes. A sample of cord blood was taken at delivery, with a follow up sample at 48 hours of age. The samples were analysed in batches, and the results were unavailable to the attending clinical staff. Infants were treated for NAS on clinical grounds according to a standardised scoring system.

RESULTS

Twenty five of 36 eligible infants over the 21 month period of the study were enrolled. Of these, 12 required treatment for NAS. Maternal methadone dose did not predict the need for treatment. However, infants who required treatment had significantly lower methadone concentrations in cord blood than the group who did not receive treatment (31 v 88 ng/ml respectively; p = 0.029). Paired blood samples for methadone concentrations were available for 17 infants. All but one of the 12 infants who required treatment had undetectable concentrations of methadone in the postnatal sample, whereas the median postnatal methadone concentration in untreated infants was 23 ng/ml (p = 0.002).

CONCLUSIONS

Methadone concentrations taken from cord blood may identify infants at greater risk of neonatal withdrawal and therefore requiring treatment.

The influence of food on the bioavailability of a twice-daily controlled release carbamazepine formulation

Carbatrol, a new dosage form of carbamazepine (CBZ), was developed consisting of three different types of pellets (immediate release, controlled release, and enteric release). The objective of this study was to explore the influence of food on absorption of CBZ. This was a randomized, open-label, single-dose crossover study conducted in 12 healthy volunteers. Treatments were 2 x 200 mg Carbatrol with a high-fat meal, fasted, or sprinkled over applesauce (but otherwise fasted). Each subject received one dose of each treatment separated by a washout period of at least 2 weeks. CBZ bioequivalence was established based on the equivalence of AUC (extent of absorption) in all three conditions. Carbatrol may be taken with or without food or the capsule opened and sprinkled on food.

Initial fluid management of diabetic ketoacidosis in children

The purpose of this study was to review the emergency department management of children presenting in diabetic ketoacidosis (DKA) to determine if current recommendations for fluid therapy are practiced. A 5-year retrospective chart review was conducted of all pediatric patients admitted with DKA to the University of Alberta Hospital. Presenting clinical and laboratory data, the initial fluid therapy, and insulin dose were analyzed. The therapy was also compared between sites of initial presentation (primary, secondary, or tertiary hospital). A total of 49 cases of DKA in 37 patients were reviewed. There were no significant clinical or biochemical differences between patients presenting at the three levels of hospital. Forty-one cases (84%) were given a saline bolus and the mean fluid volume given by 1 hour was 18.3 mL/kg. In the first hour 82% of patients presenting at a primary or secondary centre and 67% of those at the tertiary centre received more than 10 mL/kg. This excessive fluid therapy was also evident after 4 hours. Fluid management of children in DKA is excessive and not in keeping with current recommendations. Education of emergency physicians is needed to reduce fluid therapy and the risk of neurologic complications.

Rhinovirus infections in myelosuppressed adult blood and marrow transplant recipients

Scant data are available on the clinical significance of rhinovirus infections in immunocompromised patients. We reviewed the clinical courses of and outcomes for 22 myelosuppressed adult blood and marrow transplant recipients with rhinovirus infections who were hospitalized at the M.D. Anderson Cancer Center (Houston) from January 1992 to January 1997. In 15 patients (68%), illnesses remained confined to the upper respiratory tract. Seven patients (32%) developed fatal pneumonia. These patients had profound respiratory failure a mean of 12 days (range, 3-21 days) after the onset of symptoms. In six of these seven cases, rhinovirus was isolated before death from a bronchoalveolar lavage fluid specimen and/or an endotracheal aspirate. Five patients underwent autopsies, one of which revealed disseminated aspergillosis and four of which revealed interstitial pneumonitis and/or acute respiratory distress syndrome and no other organisms. In conclusion, rhinovirus infections may be associated with considerable pulmonary-related morbidity and mortality in severely myelosuppressed immunocompromised patients.

Influenza among hospitalized adults with leukemia

Influenza is one of the most important respiratory diseases of mankind, yet scant data exist concerning the frequency and clinical course of influenza in severely immunocompromised adults. From October 1993 to September 1994, we cultured the respiratory secretions of all adults with leukemia who were hospitalized with an acute respiratory illness at The University of Texas M.D. Anderson Cancer Center in Houston. During a 9-week period from 29 November 1993 to 29 January 1994, influenza virus type A (H3N2) was isolated from 15 (33%) of these 45 hospitalized adults. Twelve (80%) of the cases of influenza were associated with pneumonia, and four patients (33%) with pneumonia died. Patients who died tended to have received chemotherapy more recently and to be more myelosuppressed. Autopsy examination in two cases revealed histopathologic changes consistent with viral pneumonia. During community outbreaks, influenza is a frequent cause of serious respiratory disease in hospitalized adults with leukemia. Effective prophylactic and therapeutic regimens need to be defined for immunocompromised patients.

Respiratory disease due to parainfluenza virus in adult bone marrow transplant recipients

We reviewed the frequency and clinical course of parainfluenza virus (PIV) infections in 1,173 adult bone marrow transplant (BMT) recipients cared for at The University of Texas M.D. Anderson Cancer Center (Houston). Between January 1991 and September 1994, PIV was isolated from the respiratory secretions of 61 (5.2%) of these patients. Thirty-four (56%) of the 61 patients had uncomplicated upper respiratory tract illnesses and survived. The remaining 27 patients (44%) developed pneumonia, and the associated mortality was 37% (10 of 27 patients). Twenty-three (85%) of the patients with pneumonia had had preceding upper respiratory illnesses. Of the 10 patients who died, nine died within 100 days after transplantation. Histopathologic examination of lung tissue from seven patients revealed intracytoplasmic viral inclusions in six, a finding consistent with invasive PIV pneumonia, and viral changes in the seventh patient. Seven of the 10 patients who died had other serious concurrent infections. Of 42 patients who developed PIV infection early after transplantation (i.e., < 100 days), the frequency of pneumonia was higher among the 18 allogeneic BMT recipients (61%) than among the 24 autologous BMT recipients (42%), and the associated mortality was also higher (55% vs. 30%, respectively). PIVs are an important cause of life-threatening pneumonia in adult BMT recipients, particularly patients who have recently undergone allogeneic bone marrow transplantation.

Comparing providers' performance: problems in making the "report card" analogy fit

This article examines the applicability of a "report card" strategy as a means of differentiating among providers on the basis of performance. The specific focus is on the potential effect of differences in data collection processes on the meaningfulness of subsequent comparisons among similar types of providers. Variations in reported nosocomial infection rates are analyzed in light of differences in reported surveillance practices; data for similar nursing units are analyzed as well. Thirty-one rural, rural referral, and urban acute care hospitals in the midwest participated in the study. The reported nosocomial infection rates for different types of nursing units and different hospital groups varied substantially. Likewise, there were marked variations in the nosocomial infection surveillance practices at the hospitals, which were found to explain some of the variation in the reported nosocomial infection rates for specific types of nursing units and nosocomial infections. The study conclude that differences in data collection processes may result in incorrect conclusions about differences in the quality of care provided by various providers.

In vivo dosimetry of ethylene oxide and propylene oxide in the cynomolgus monkey

In mammals, including the cynomolgus monkey, a striking difference between the potencies of ethylene oxide (EO)* and propylene oxide (PO) with respect to induction of certain clastogenic effects has previously been observed. In order to clarify to what extent such differences can be ascribed to a difference in detoxification rate, cynomolgus monkeys were administered an equimolar mixture of the two epoxides at two dose levels, and the blood doses were determined by measurement of the degree of alkylation of N-terminal valines in hemoglobin (Hb). For the highest exposure a saturation in the detoxification of PO was evident from a marked increase in adduct level. At the lower exposure, the dose in blood resulting from exposure to PO was about one fourth of that from EO. Although playing a great role, differences in detoxification rate, therefore, cannot fully account for the much lower clastogenic potency of PO, which has been found in earlier studies. Furthermore, the determination of doses in blood gives data on relationship between in vivo dose and exposure dose (accounting for detoxification), with relevance for risk estimation.

Comparison of US inactivated split-virus and Russian live attenuated, cold-adapted trivalent influenza vaccines in Russian schoolchildren

In a blinded, placebo-controlled study, the reactogenicity, immunogenicity, and clinical efficacy of single doses of US inactivated split-virus and Russian live attenuated, cold-adapted influenza vaccines were compared in 555 schoolchildren in Vologda, Russia. Serial serum samples were collected and school absenteeism was assessed. Systemic reactions were rare, but local reactions (primarily erythema at the injection site) were observed in 27% of the inactivated vaccine group, and coryza (12%) and sore throat (8%) were observed in the attenuated vaccine group. At 4 weeks after vaccination a > or = 4-fold rise in titer of hemagglutination inhibition antibody to A (H1N1), A (H3N2), and B was noted, respectively, among 78%, 88%, and 53% of children who received inactivated vaccine and among 55%, 79%, and 30% of children who received attenuated vaccine. The vaccine efficacy for preventing school absenteeism due to respiratory illness during the period of peak influenza activity was 56% for inactivated vaccine and 47% for attenuated vaccine.

Lack of methylation of inorganic arsenic in the chimpanzee

Most mammals methylate inorganic arsenic (As) to methylarsonic acid (MMA) and dimethylarsinic acid, which are rapidly excreted in the urine. Previous studies have shown that, in contrast to humans, all experimental animals excrete very little MMA. With the aim of finding an appropriate animal model for studies on inorganic As metabolism and toxicity, we have investigated the metabolism of As in two male chimpanzees after a single iv dose of [73As]arsenate (5.8 micrograms As/kg body wt). The initial clearance from plasma was rapid with an apparent half-time of about 1 hr. Urine was found to constitute the major excretory pathway with very little excretion in the feces. About 60% of the administered 73As dose was excreted in the urine within 96 hr in a biphasic manner. The second phase of slow urinary excretion was characterized by first-order kinetics with a half-time of about 7 days. Upon ion-exchange chromatography of ultrafiltrated plasma and urine, only inorganic As could be detected, a finding confirmed by thin-layer chromatography. Thus, the results indicate that the chimpanzee, as previously shown for the marmoset monkey, but unlike all other mammals studied so far, including humans, is unable to methylate and detoxify inorganic As.

Epidemiology of influenza A virus infection in patients with acute or chronic leukemia

Influenza infection is a significant cause of morbidity and mortality in immunocompromised hosts, but its importance in adult cancer patients is largely undescribed. We therefore conducted a prospective study of the incidence and clinical features of influenza infection in patients with acute or chronic leukemia. The cohort, which consisted of all adult leukemia patients undergoing remission-induction chemotherapy during the 1991-1992 influenza epidemic, was followed prospectively for development of signs and symptoms of acute infection of the upper or lower respiratory tract. Of these 294 patients, 111 received chemotherapy as inpatients and 183 as outpatients. Throat swabs and nasal washes for viral culture were obtained from all symptomatic patients, who were then followed until all signs and symptoms resolved. Symptoms of respiratory tract infection developed in 37 leukemia patients (13%). Among these, influenza (A/Beijing/ H3N2) caused 3 (21%) of the 14 infections that developed during hospitalization but only 1 (4%) of the 23 that developed in the community (P = 0.14). Influenza patients presented with fever, rhinorrhea, nasal congestion, headache, and myalgia; those with other infections presented with signs and symptoms of lower respiratory tract infection (productive cough, rales, or rhonchi). Development of pneumonia was common in influenza patients, 1 of whom died from secondary fungal and gram-negative pneumonia. Influenza A virus infections accounted for a substantial portion of acute respiratory infections among adult leukemia patients during a community epidemic. Most infections appeared to be nosocomial and the most likely sources were visitors or hospital personnel. Immunization of household contacts and hospital staff may reduce the risk of influenza infection and its pulmonary complications in leukemia patients.

Fetal thyrotoxicosis: a case report and recommendations for prediction, diagnosis, and treatment

A maternal history of Graves' disease places the fetus at risk for thyrotoxicosis in utero via the placental transfer of thyroid-stimulating immunoglobulins. Methods for prediction of fetal hyperthyroidism are available, but are not widely used. Clinical assessment of fetal thyroid status by monitoring of fetal heart rate and growth may be inaccurate. This raises some uncertainty in the initial diagnosis of fetal thyrotoxicosis and complicates the assessment of fetal response to maternal propylthiouracil therapy. A case illustrating these pitfalls in the diagnosis and management of fetal hyperthyroidism is presented. The condition was correctly diagnosed, but treatment based on fetal heart rate resulted in biochemical hypothyroidism in the infant at birth. Current recommendations for diagnosis and treatment of fetal hyperthyroidism are reviewed along with recent developments in the field. A modified approach is proposed.

Theophylline target concentration in severe airways obstruction - 10 or 20 mg/L? A randomised concentration-controlled trial

The optimal serum concentration of theophylline for the management of acute airways obstruction was evaluated by comparing the response to target concentrations at the extremes of the usual therapeutic range. 174 patients requiring intravenous theophylline were randomly assigned to a target concentration of 10 or 20 mg/L. Control of theophylline dosage using measured theophylline concentrations and evaluation of efficacy and toxicity was performed under double-blind conditions. 87 patients (50%) required hospital admission. Of these, 54 patients (62%) were followed throughout their hospital admission and reviewed at an outpatient clinic approximately 1 week after discharge. The duration of hospital stay, and rate and extent of improvement in peak expiratory flow rate were not different between the groups. There was significantly more toxicity in the 20 mg/L group. The initial target concentration for theophylline in the management of acute airway obstruction should be 10 mg/L under circumstances where concentration is used to control theophylline dosages.

Antibody response to a two-dose influenza vaccine regimen in adult lymphoma patients on chemotherapy

A study was conducted to determine if a two-dose regimen of influenza vaccine would enhance the immunologic response of 41 patients with lymphoma receiving chemotherapy. Hemagglutinin-inhibiting antibody responses to influenza A/H1N1, A/H3N2 and B virus occurred in 32%, 24% and 20% of patients following one dose, and in 49%, 41% and 46% of patients following two doses, respectively. Responses to one or more vaccine components occurred in 42% of patients after one dose and in 71% after two doses. Fifty percent of the patients who did not respond after one dose responded after two doses. A two-dose regimen of influenza immunization may significantly enhance the response rate of cancer patients receiving chemotherapy.

Pilot evaluation of influenza virus vaccine (IVV) combined with adjuvant

The safety of licensed influenza virus vaccine (IVV) combined with a novel adjuvant containing muramyl tripeptide (MTP) conjugated to phosphatidylethanolamine (PE) was evaluated in a randomized pilot study. Ten healthy 23-30-year-old men were given a single intramuscular dose of IVV combined with saline (n = 5) or with 100 micrograms of MTP-PE in the MF59 adjuvant emulsion (MF59-100) (n = 5). Evaluations were performed on days 0, 1, 2, 4, 7 and 28 after inoculation. IVV alone was well tolerated. All volunteers immunized with IVV/MF59-100 experienced moderate to severe local and systemic reactions which interfered with usual activities. Discomfort at the injection site was first noted at 2-6 h; induration (5/5), erythema (3/5), and regional adenopathy (3/5) persisted for up to 4 days. Systemic symptoms including chills (5/5), fever (3/5), nausea (3/5) and/or dizziness (2/5) developed within 12 h of inoculation and resolved by 48 h. Elevated white blood cell count (days 1 and 2), erythrocyte sedimentation rate and serum fibrinogen were transiently observed. Although peak serum neutralizing antibody titres versus influenza A/H3N2 and influenza B antigens were higher in the group given IVV with MF59-100, these unexpected reactions indicate that this dose of adjuvant is unsuitable for use in combination with this IVV.

Interspecies comparison of the pharmacokinetics of aldose reductase inhibitors

The pharmacokinetics of three aldose reductase inhibitors (ARIs) were evaluated in various species, including rat, dog, cynomolgus monkey, rhesus monkey, chimpanzee, and man. The three ARIs (AL01567, AL01576, and AL01750) were administered intravenously as a single dose to all species except rat, which was dosed orally with AL01750, and man, who was dosed orally with AL01567 and AL01576. Plasma drug concentrations were measured by HPLC or liquid scintillation spectrometry and various pharmacokinetic parameters (clearance, CL; Vd, volume of distribution; and t1/2) were calculated from the data. Overall the pharmacokinetics of the three compounds were quite similar, each being characterized by low CL, intermediate Vd, and long t1/2. For AL01576, mean CL ranged from 0.21 ml/min/kg in cynomolgus monkey to 0.91 ml/min/kg in dog, mean Vd from 0.66 liter/kg in cynomolgus monkey to 2.4 liters/kg in dog and man and mean t1/2 from 29 hr in dog to 72 hr in man. Mean CL of AL01567 ranged from 0.14 ml/min/kg in man to 1.4 ml/min/kg in dog, mean Vd from 0.45 liter/kg in rat to 3.5 liters/kg in dog and mean t1/2 from 22 hr in rhesus monkey to 63 hr in man. Mean CL of AL01750 ranged from 0.13 ml/min/kg in chimpanzee to 1.3 ml/min/kg in dog, mean Vd from 0.40 liter/kg in rat to 1.8 liters/kg in dog and mean t1/2 from 12 hr in rhesus monkey to 62 hr in chimpanzee. For all three drugs, CL and Vd corrected for body weight were quite similar in all species except dog, whose CL and Vd were two- to fourfold greater than the other animals.(ABSTRACT TRUNCATED AT 250 WORDS)

The evolution of air transport systems: a pictorial review

The air transport of patients began over seventy years ago in primitive biplanes. The ability to fly over the obstacles of the battlefield created enthusiasm in both the military and the medical communities. With the advent of vertical flight, the need for conventional runways was obviated allowing for casualties to be transported directly from the site of injury. After their introduction as air ambulances in 1945, helicopters soon supplanted ground ambulances with their speed and versatility. By the mid-1960s, civilian casualties were being transported by helicopter as regional trauma care developed in the United States. Today aeromedical programs continue to expand rapidly, even as closer scrutiny of their efficacy, cost, and safety are explored. A pictorial review highlighting the evolution of air transport systems is presented.

The changing picture of pseudotumor cerebri in children

Among 38 children with pseudotumor cerebri only 3 cases were due to ear disease or its complications. The commonest cause was a refeeding syndrome either due to nutritional deprivation or as an early finding in the treatment of cystic fibrosis. It is uncommon to find the cause of pseudotumor in older children but in those under 6 years the cause was found in 85%. Because of the adverse effects of steroids we use this treatment in the more resistant cases.

Suturable gastrointestinal cannulas for animals of various sizes

A new procedure in which gastrointestinal cannulas are prepared from suturable material improves in vovo methods and requires little machining. Substitution of a suturable material for rigid collars, previously used, prevents leakage, infection, and loss of the cannulas into the gut lumen. The technique has been successfully applied to rats, rabbits, and dogs; consequently it should be useful in animals of almost any size. Two designs of cannulas with descriptions of their implantation are presented. The first version fits into each end of a gut loop and is useful for perfusion, digestion, and secretion studies. The second version forms a sidearm through which feeding or sampling can be carried out at any point in the intestine or the stomach.