Gastrointestinal microbiome, what is behind faecal microbiota transplantation?

The intestinal microbiota is made up of billions of microorganisms that coexist in an organised ecosystem, where strict and facultative anaerobic bacteria predominate. The alteration or imbalance of these microorganisms, known as dysbiosis, can be associated with both gastrointestinal and extraintestinal diseases. Based on a review of the literature, the intestinal microbiota is described in its state of health, the changes associated with some gastrointestinal diseases and the potential role that faecal microbiota transplantation has in the reestablishment of an altered ecosystem. Undoubtedly, the information revealed makes us reflect on the indication of faecal microbiota transplantation in various pathologies of intestinal origin. However, to ensure the efficacy and safety of this therapy, more studies are needed to obtain more evidence.

Outcomes of transcatheter vs. isolated surgical aortic valve replacement in mediastinal radiation-associated severe aortic stenosis

Introduction

Mediastinal radiation can lead to long-term cardiac sequelae, including aortic valve disease. Surgical aortic valve replacement (SAVR) is associated with poor outcomes in this population. Transcatheter aortic valve replacement (TAVR) now provides an alternative treatment strategy that may improve outcomes.

Purpose

To compare 30-day outcomes after TAVR vs. isolated SAVR for radiation-associated severe symptomatic aortic stenosis using the Society of Thoracic Surgery (STS) National Adult Cardiac Surgery Database.

Methods

We evaluated 1,668 TAVR and 2,611 isolated SAVR patients enrolled in the STS national database from July 2011 through December 2018. A propensity score for TAVR vs. SAVR was derived using a non-parsimonious logistic regression model that included 29 pre-operative variables and was used to generate a 1:1 matched cohort (NTotal=1,560). 30-day outcomes in TAVR vs. SAVR patients were compared in the matched cohort using conditional logistic regression. We also tested for temporal trends in 30-day mortality separately for TAVR and SAVR in the matched cohort, adjusted for potential confounders, to see if outcomes varied across the study period.

Results

In the propensity-matched cohort, baseline demographics, comorbidities and preoperative characteristics were balanced between the TAVR and SAVR groups. The mean age was 73.3 years and 75% were females in each group. In the propensity-matched cohort, TAVR was associated with significantly reduced 30-day all-cause [OR=0.50 (0.30–0.84), p=0.01] and cardiovascular mortality as compared to SAVR [OR=0.33 (0.14–0.78), p=0.01]. Similarly, post-operative complications occurred less in the TAVR group except for stroke/transient ischemic attack (TIA) [OR=3.17 (1.27–7.93), p=0.01] and pacemaker implantation [OR=1.71 (1.21–2.44), p=0.003] which were significantly higher with TAVR (Figure 1A). While, 30-day mortality associated with both procedures improved over the course of the study, the trend was only statistically significant in the TAVR group following adjustment for potential confounders. TAVR was consistently associated with better survival than SAVR in the matched cohort across the study period (Figure 1B).

Conclusion

Our findings suggest that TAVR is a safe alternative to SAVR for radiation-associated severe symptomatic aortic stenosis and is associated with lower 30-day mortality and post-operative complications. The risk of stroke/TIA and pacemaker implantation is higher with TAVR and should be considered when choosing therapy. Additional prospective studies to validate our findings and evaluate long-term outcomes are needed to further guide clinical decision making in this population.

Figure 1

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Funding to support acquisition of the data from the Society of Thoracic Surgery was obtained from discretionary funds available to Dr. Anju Nohria from the Cardiovascular Medicine Division.

Associationbetween hyperoxia and mortality in severely burned patients

INTRODUCTION

The use of oxygen is a key component of acute burn resuscitation, particularly when there is concern for carbon monoxide toxicity or inhalation injury. Prior studies of critically-ill patients have shown an association between early hyperoxia and increased mortality. There are no studies to date evaluating outcomes related to excessive oxygen administration in burn patients.

METHODS

We conducted a retrospective analysis of 219 severely burned patients to quantify the average amount of oxygen given during initial resuscitation, the level of carbon monoxide exposure, and to determine if early exposure to supratherapeutic oxygen was associated with increased hospital mortality or ventilator-associated pneumonia (VAP). The models were adjusted for inhalation injury and total body surface area (TBSA) burned.

RESULTS

Early hyperoxia in severely burn patients is common and possibly associated with increased overall mortality, although the results were inconclusive and after adjusting for burn-specific scoring systems, we found a negative correlation between hyperoxia and mortality. Confirmed carbon monoxide poisoning was relatively uncommon, but also associated with increased mortality. Patients with elevated carboxyhemoglobin did not receive more oxygen compared to others within the cohort.

CONCLUSIONS

Burn patients are exposed to higher concentrations of pure oxygen compared to other critically-ill patients, presumably for empiric treatment of carbon monoxide poisoning. Our data showed a liberal use of oxygen therapy across all patients. Considering the potentially negative effects of hyperoxia, this study exposes either a gap in clinical research or need for clearer indications.

Deep Transfer Learning and Radiomics Feature Prediction of Survival of Patients with High-Grade Gliomas

BACKGROUND AND PURPOSE

Patient survival in high-grade glioma remains poor, despite the recent developments in cancer treatment. As new chemo-, targeted molecular, and immune therapies emerge and show promising results in clinical trials, image-based methods for early prediction of treatment response are needed. Deep learning models that incorporate radiomics features promise to extract information from brain MR imaging that correlates with response and prognosis. We report initial production of a combined deep learning and radiomics model to predict overall survival in a clinically heterogeneous cohort of patients with high-grade gliomas.

MATERIALS AND METHODS

Fifty patients with high-grade gliomas from our hospital and 128 patients with high-grade glioma from The Cancer Genome Atlas were included. For each patient, we calculated 348 hand-crafted radiomics features and 8192 deep features generated by a pretrained convolutional neural network. We then applied feature selection and Elastic Net-Cox modeling to differentiate patients into long- and short-term survivors.

RESULTS

In the 50 patients with high-grade gliomas from our institution, the combined feature analysis framework classified the patients into long- and short-term survivor groups with a log-rank test P value < .001. In the 128 patients from The Cancer Genome Atlas, the framework classified patients into long- and short-term survivors with a log-rank test P value of .014. For the mixed cohort of 50 patients from our institution and 58 patients from The Cancer Genome Atlas, it yielded a log-rank test P value of .035.

CONCLUSIONS

A deep learning model combining deep and radiomics features can dichotomize patients with high-grade gliomas into long- and short-term survivors.

A comparison of injury scoring systems in predicting burn mortality

The models most widely used to predict burn patient mortality are the revised Baux score, Ryan, Smith, McGwin, Abbreviated Burn Severity Index (ABSI), Belgian Outcome of Burn Injury (BOBI), and the Fatality by Longevity, APACHE II score, Measured Extent of burn, and Sex (FLAMES). Improvements in critical care have reduced mortality resulting from severe burns, which may affect the predictive strength of older models. We conducted a cross-validation study on all burn patients (n = 114) with TBSA greater than 20%, admitted to the Arizona Burn Center between 2014 and 2016. The study compared the accuracy of seven previously validated burn-specific models and one new model derived for our cohort. Data were collected on age, ethnicity, gender, total body surface area burned (TBSA), inhalational injury, associated trauma, and injury severity (ISS, APACHE II). The accuracy of each model was tested using logistic regression, preserving the published regression coefficients. Predictive performance of the models was assessed by Receiving Operator Curve (ROC) curve analyses and Hosmer-Lemeshow (H-L) goodness of fit tests. Age, TBSA and APACHE II score were found to be significant, independent risk factors for patient mortality. The FLAMES model performed best (AUC 0.96) and was comparable to our native model (AUC 0.96). The revised Baux score was both accurate and easy to calculate, making it clinically useful. The older models demonstrated adequate predictive performance compared with the newer models. Even without key burn parameters, the APACHE II score performed well in critically ill patients with moderate to severe burn injuries.

Comparing effects of insulin analogues and human insulin on nocturnal glycaemia in hypoglycaemia-prone people with Type 1 diabetes

AIMS

To assess the difference between analogue and human insulin with regard to nocturnal glucose profiles and risk of hypoglycaemia in people with recurrent severe hypoglycaemia.

METHODS

A total of 72 people [46 men, mean ± sd age 54 ± 12 years, mean ± sd HbA_1c 65 ± 12 mmol/mol (8.1 ± 1.1%), mean ± sd duration of diabetes 30 ± 14 years], who participated in a 2-year randomized, crossover trial of basal-bolus therapy with insulin detemir/insulin aspart or human NPH insulin/human regular insulin (the HypoAna trial) were studied for 2 nights during each treatment. Venous blood was drawn hourly during sleep. Primary endpoints were nocturnal glucose profiles and occurrence of hypoglycaemia (blood glucose ≤ 3.9 mmol/l).

RESULTS

During insulin analogue treatment, the mean nocturnal plasma glucose level was significantly higher than during treatment with human insulin (10.6 vs 8.1 mmol/l). The fasting plasma glucose level was similar between the treatments. Nocturnal hypoglycaemia was registered during 41/101 nights (41%) in the human insulin arm and 19/117 nights (16%) in the insulin analogue arm, corresponding to a hazard ratio of 0.26 (95% CI 0.14 to 0.45; P < 0.0001) with insulin analogue.

CONCLUSIONS

Treatment with insulin analogue reduces the occurrence of nocturnal hypoglycaemia assessed by nocturnal glucose profiles in people with Type 1 diabetes prone to severe hypoglycaemia. Nocturnal glucose profiles provide a more comprehensive assessment of clinical benefit of insulin regimens as compared to conventional recording of hypoglycaemia.

Alterations of pituitary adenylate cyclase-activating polypeptide-like immunoreactivity in the human plasma during pregnancy and after birth

BACKGROUND

Since its discovery, several distinct effects of pituitary adenylate cyclase activating polypeptide (PACAP) have been established - predominantly in animal studies - in the nervous system, various peripheral organs as well as in the endocrine regulation. It is unknown whether PACAP has any effect on human pregnancy regarding either utero-maternal or perinatal aspects of the gestation.

AIM

We investigated alterations of PACAP38-like immunoreactivity (PACAP38-LI) in the human plasma throughout normal pregnancy, during and after delivery, and its level in the umbilical vessels, as well as in the peripheral blood of term healthy newborns.

MATERIALS AND METHODS

A 2 ml blood sample was used for each test, PACAP38-LI was determined by radioimmunoassay.

RESULTS

In the 2nd and 3rd trimester significant elevation was observed in the PACAP38-LI compared to the earlier gestation and non-pregnant conditions. During delivery its level significantly decreased and returned to the original values 3 days after birth. In the neonates PACAP38-LI level of the peripheral blood was similar to that of healthy adults, but umbilical arteries and veins contained significantly lower concentrations of PACAP38-LI. Besides, the levels were lower in the umbilical vein compared to the artery.

CONCLUSIONS

PACAP38-LI levels show sensitive change during normal pregnancy and delivery. Our findings suggest that the fetal organs actively synthesize PACAP. Further investigations are required to elucidate the physiological importance of the alterations observed.

Normal cognition and behavior in a Smith-Lemli-Opitz syndrome patient who presented with Hirschsprung disease

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder of cholesterol biosynthesis. It is caused by mutations in the gene encoding the enzyme 7-dehydrocholesterol Delta7-reductase (DHCR7), which catalyzes the final step in cholesterol biosynthesis, usually resulting in cholesterol deficiency. We report a 3.5-year-old girl who has cognition in the low average range and normal behavior, but in whom molecular studies identified two missense mutations in DHCR7: V326L and F284L. She was born at term following an uncomplicated pregnancy and delivery, and presented at 12 days of age with poor feeding, abdominal distention, and jaundice. Colonic biopsy was consistent with Hirschsprung disease. On physical examination she had mild ptosis, a long philtrum, mild micrognathia, a short, upturned nose, and subtle 2,3 syndactyly. Her 7-dehydrocholesterol (7-DHC) level was markedly elevated at 8.7 mg/dl (normal 0.10 +/- 0.05), and her cholesterol level was normal at 61 mg/dl (normal for newborn period 50-80 mg/dl). Karyotype analysis was normal, 46,XX. Breast milk feeding was initiated and continued for 18 months. Cholesterol supplementation was implemented at 100 mg/kg/day at 3 months, which resulted in increased cholesterol levels and reduced dehydrocholesterol levels. Neuropsychological testing has shown functioning in the low average range, between the 14th and 18th centiles when compared to peers. This is markedly higher than most children with SLOS. She has no behavioral problems. MRI and MRS testing of the brain revealed no structural abnormalities. This is in contrast to a recently reported case by Prasad et al. [2002: Am J Med Genet 108:64-68] with a mild phenotype, behavioral problems, and abnormal MRI, who is compound heterozygote for both a null and missense mutation. Our case suggests that patients with severe feeding disorders with or without Hirschprung disease and postnatal onset microcephaly may warrant screening for SLOS.

MRI and 1H MRS findings in Smith-Lemli-Opitz syndrome

Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive disorder characterized by a defect in cholesterol biosynthesis, associated with mental retardation and multisystem structural abnormalities. This study investigated the prevalence of congenital CNS abnormalities by MRI in a large series of patients with SLOS and the correlation of the clinical and biochemical findings with the results of MRI and 1H MRS. Eighteen patients were studied; all underwent MRI of the brain, and 16 had 1H MRS of the cerebral white matter. The ratios choline:NAA, lipid:NAA, and lipid:choline metabolite were found to be correlated with the clinical degree of disease severity, serum total sterol ratios (cholesterol/cholesterol + 7-dehydrocholesterol + 8-dehydrocholesterol) and in two cases with the effect of cholesterol therapy. Abnormal CNS findings were noted in five patients, including callosal abnormalities (n = 4), Dandy-Walker variant (n = 1), and arachnoid cyst (n = 1). Holoprosencephaly was noted in one patient with a prevalence of 6%. Choline:NAA was elevated in seven patients. There was a statistically significant positive correlation between the lipid:choline ratio and the serum cholesterol precursor, 8-dehydrocholesterol. In two patients 1H MRS demonstrated abnormally elevated lipids prior to cholesterol therapy, which improved on therapy. The use of MRI and 1H MRS is an effective way to demonstrate brain structural abnormalities in patients with SLOS and may prove to be an effective method for the assessment of the effects of cholesterol replacement therapy in the brain.

Motor vehicle crash fatalities by race/ethnicity in Arizona, 1990-96

OBJECTIVE

To compare rates of motor vehicle crash (MVC) fatalities among different race/ethnic groups in urban and rural Arizona.

METHOD

Using the Fatality Analysis Reporting System and the National Center for Health Statistics Multiple Cause of Death file, MVC fatalities in Arizona from 1990-96 inclusive were classified by gender, race/ethnicity, and urban or rural residence. Age adjusted rates of total, occupant, pedestrian, and alcohol related fatalities were calculated. The total MVC fatality rate for each race/ethnic group was then adjusted for proportion of rural residence.

RESULTS

Compared with non-Hispanic whites (NHWs), American Indians had raised relative risks for MVC fatality in all gender and residence subgroups. Hispanic females and rural Hispanic males had lower relative risks, as did rural African-American men. Raised relative risks for American Indian men and women included all subgroups: total, occupant, pedestrian, and alcohol related. Hispanic and African-American men both had raised relative risks of pedestrian related fatalities, and Hispanic men had a slightly higher relative risk while Hispanic women had a lower relative risks, for alcohol related fatality. Hispanic men and women and African-American men had lower occupant fatality rates. Close to half (45%) of the excess MVC fatality among American Indians can be attributed to residence in rural areas, where MVC fatality rates are higher. There were 1.85 occupants in crashes involving NHW deaths compared with 2.51 for Hispanics and 2.71 for American Indians (p<0.001). The proportion of occupants not using a seatbelt was higher in Hispanics and American Indians in both urban and rural areas.

CONCLUSION

The major disparity in MVC fatality in Arizona is among American Indians. The higher MVC fatality rates among American Indians occur in all age groups, in both urban and rural areas, and among occupants and pedestrians. Rural residence, lower rates of seatbelt use, higher rates of alcohol related crashes, a greater number of occupants, and higher rates of pedestrian deaths all contribute to the American Indian MVC fatality disparity. High rates of pedestrian fatality occur in men in all three race/ethnic minorities in Arizona and among American Indian women. In contrast to other studies, African-Americans and Hispanics did not have raised total MVC fatality rates and compared to NHWs actually had lower rates in the rural areas of the state.

Neurologic nonmetabolic presentation of propionic acidemia

BACKGROUND

Patients with propionic acidemia usually present in the neonatal period with life-threatening ketoacidosis, often complicated by hyperammonemia. It was thought that the neurologic abnormalities seen in this disease were exclusively the consequences of these acute crises. Experience with 2 patients with propionic acidemia indicates that this disease may present first with prominent neurologic disease without the life-threatening episodes of ketoacidosis that usually serve as the alerting signals for a diagnosis of an organic acidemia.

OBJECTIVE

To examine the clinical and metabolic aspects of 2 patients with a phenotype that suggested disease of the basal ganglia.

DESIGN

Examination of patterns of organic acids of the urine and enzyme assay for propionyl-CoA carboxylase in fibroblasts and lymphocytes.

SETTING

Referral population to a biochemical genetics laboratory.

PATIENTS

Two patients whose prominent features were hypotonia followed by spastic quadriparesis and choreoathetosis. Both had seizures. One patient was mildly mentally retarded but grew normally physically. The other had profound mental retardation and failure to thrive; he also self-mutilated his lower lip. Self-injurious behavior has not been reported in this disease.

MAIN OUTCOME MEASURES

Clinical description, blood ammonia levels, organic acid levels in the urine, and enzyme activity.

RESULTS

Excretion of metabolites, including methylcitrate, was typical. Residual activity of propionyl-CoA carboxylase approximated 5% of the control in each patient.

CONCLUSIONS

Propionic acidemia can present as a pure neurologic disease without acute episodes of massive ketoacidosis. Hyperammonemia may occur after infancy in some patients, presenting as Reye syndrome.

Carbon dioxide dynamics during apneic oxygenation: the effects of preceding hypocapnia

STUDY OBJECTIVE

To compare the rate of increase of arterial carbon dioxide tension (PaCO2) during apneic oxygenation preceded by acute respiratory hypocapnia with that during apnea preceded by respiratory eucapnia.

DESIGN

Randomized, prospective, single crossover study.

SETTING

Operating room at a teaching hospital.

PATIENTS

19 ASA physical status I, II, and III patients requiring general endotracheal anesthesia and invasive monitoring for elective surgery.

INTERVENTIONS

Two ventilatory states preceding apneic oxygenation were studied in each patient. The first respiratory state was established using controlled mechanical ventilation in the stable, anesthetized patient, followed by a 5-minute period of apneic oxygenation. Arterial and mixed central venous blood gas samples were obtained simultaneously prior to and at 1-minute intervals during apnea. Ventilatory parameters were then changed to establish the second respiratory state. During the subsequent period of apnea, the study was repeated as above.

MEASUREMENTS AND MAIN RESULTS

Arterial and mixed central venous partial pressure of carbon dioxide (pCO2) levels were measured. A greater increase in PaCO2 was found during the first minute of apneic oxygenation in the hypocapneic group compared with the eucapneic group. The venoarterial gradient of pCO2 was also greater in the hypocapneic group prior to apnea.

CONCLUSIONS

Acute hypocapnia compared with eucapnia prior to apneic oxygenation is associated with a greater rise in PaCO2 in the anesthetized patient. This finding may be due in part to widening of the venoarterial gradient of pCO2.

The use of albuterol in hospitalized infants with bronchiolitis

OBJECTIVES

To determine whether the use of albuterol by nebulization enhances physiologic or clinical recovery in hospitalized infants with moderate bronchiolitis.

METHODS

This prospective, double-blind, placebo-controlled, randomized clinical trial was performed from December 1995 to March 1996. A total of 52 patients <24 months of age with a diagnosis of moderately severe, acute viral bronchiolitis were enrolled and assigned to receive nebulized albuterol or normal saline placebo for 72 hours under a standardized protocol. Primary outcome measures included improvement in oxygen saturation (SaO2) during hospitalization and survival analysis to assess the time required to reach preestablished discharge criteria on three measures: SaO2, accessory muscle use, and wheezing. An additional secondary outcome measure was actual length of hospital stay. Adverse outcomes also were compared between treatment groups.

RESULTS

There was no significant difference in mean SaO2 between albuterol and placebo at baseline, 24 hours, or maximum SaO2 achieved during hospitalization. Both groups showed significant improvement in oxygen saturation over time, but there was no significant difference in improvement between the two groups. The study had a power of 90% to detect a difference in mean percentage point improvement of 2% SaO2. There was no difference in time to reach discharge criteria as defined by SaO2, accessory muscle use, or wheezing. There was no difference in length of hospital stay or in the frequency of adverse outcomes.

CONCLUSIONS

Nebulized albuterol therapy does not appear to enhance recovery or attenuate severity of illness in infants hospitalized with acute, moderate bronchiolitis, as evidenced by improvement in oxygen saturation, time to meet standardized discharge criteria, or length of hospital stay.

The rat subcutaneous air sac model: a new and simple method for in vivo screening of antiangiogenesis

An experimental rat model, the Subcutaneous Air Sac (SAS) model, was developed to provide an animal model in which neo-vascularization can be easily assessed in situ and quantified using a radiolabelled plasma marker. The SAS model was designed to replace a previous model where neovascularization was induced by chemical injury of rat or rabbit cornea or by implantation of tumour cells intracorneally, a methodology which is believed to cause severe pain to the animals. In the SAS model the air sac replaces the cornea as a transparent avascular substratum in which vascularization can be observed. The air sac is induced by injection of air subcutaneously on the back of the animal. After 8 to 10 days a sufficient air sac has been established. The animal is anaesthesized and by a minor operation the cellulose sponge is implanted upon the air sac under the skin. The vasoproliferative effect of the cellulose sponge causes formation of new vessels which are macroscopically visible 10 days after implantation. The ability of the in vivo SAS model to show an antiangiogenic effect of a systemically applied test compound was investigated using the fumagillin analogue TNP-470 (ochloro-acetylcarbamoyl)-fumagillol) as a positive control at dose levels of 0, 1, 2.5, 5 and 10 mg/kg/day given subcutaneously for 10 days. The neo-angiogenesis was scored both in situ using a subjective point system and by measuring the 125I-activity of the implant and the membrane after an intravenous injection of 125I-labelled antibodies. The neo-angiogenesis was reduced by approximately 45-50% in animals treated with 5 or 10 mg/kg/day of TNP-470 compared to animals treated with the vehicle. The animals treated with 10 mg/kg/day TNP-470 showed signs of toxicity. The SAS model is considered highly relevant for in vivo testing of potential antiangiogenic drugs on humane grounds. The high reproducibility, the low cost and the technical simplicity of the method makes it attractive.

Analgesia for emergency centers' orthopaedic patients: does an ethnic bias exist?

Several prior studies have demonstrated that Hispanics treated in some emergency centers were prescribed less analgesia than white patients with similar extremity trauma. The purpose of this study was to determine if other institutions had a similar experience with regard to undermedication of certain ethnic groups. Two cohorts were studied, 1 adult and 1 pediatric group. The adult group consisted of 84 patients seen at Maricopa Medical Center, Phoenix, Arizona, between January 1, 1992, and December 31, 1992, who were treated for isolated long bone fractures requiring a closed reduction. The pediatric group consisted of 63 children younger than 16 years, seen between January 1, 1992, and April 30, 1993, with isolated distal radius or ulna fractures requiring a closed reduction. Results indicated that Hispanics were not likely to be undermedicated for fracture reduction in this level I trauma emergency center compared with whites. It is thought that a hospital with a larger populations of underrepresented minorities may be more sensitive than other private institutions.

Is academic managed care an oxymoron?

BACKGROUND

A review of 1993 data on length of stay (LOS) and charges for diagnosis-related group (DRG) 195 (complicated cholecystectomies) showed that Maricopa Medical Center charged more and had longer LOS than all other area hospitals.

METHODS

Twenty DRG 195 charts were analyzed for the causes of the inefficiencies. The remaining cholecystectomy DRGs were similarly analyzed.

RESULTS

Analysis of the charts for DRG 195 showed that 55% of the patients had laparoscopic conversions. Charges and LOS varied significantly because of the conversions, increased preoperative hospital days and increased operative times. Moreover, 30% of patients were more than 70 years old. Comparisons of other cholecystectomy DRGs showed similar inefficiencies, indicating a hospital system's problem.

CONCLUSIONS

Diagnosis-related group delta analysis is a powerful performance improvement tool. Once problem areas are identified and corrected, monitoring prospective data produces rapid analysis of quality of care and cost improvements. The models can serve as a means for teaching hospitals to become more competitive and satisfy the Joint Commission on Accreditation of Healthcare Organizations requirements for patient-care improvements.

Linkage of a human brain malformation, familial holoprosencephaly, to chromosome 7 and evidence for genetic heterogeneity

Holoprosencephaly (HPE) is a common malformation of the developing forebrain and midface characterized by incomplete penetrance and variable expressivity. Familial HPE has been reported in many families with autosomal dominant inheritance in some and apparent autosomal recessive inheritance in others. We have examined 125 individuals from nine families with autosomal dominant HPE. Expression in gene carriers varied from alobar HPE and cyclopia through microforms such as microcephaly or single central incisor to normal phenotype. We performed linkage studies by either Southern blot or polymerase chain reaction analyses with DNA markers (D7S22, D7S550, and D7S483) that are deleted from some patients with sporadic HPE and flank a translocation breakpoint in 7q36 associated with HPE. The strongest support for linkage was with D7S22, which was linked with no recombination to autosomal dominant HPE in eight of nine families with a combined logarithm of odds score of 6.4 with an affected-only model-free analysis and 8.2 with a reduced-penetrance model and all phenotypes. Close linkage to this region could be excluded in one family, and there was significant evidence of genetic heterogeneity. These results show that a gene for autosomal dominant HPE is located in a chromosomal region (7q36) known to be involved in sporadic HPE with visible cytogenetic deletions. They also demonstrate genetic heterogeneity in familial HPE. We hypothesize that mutations of a gene in 7q36, designated HPE3, are responsible for both sporadic HPE and a majority of families with autosomal dominant HPE.

Mild Brachmann-de Lange syndrome. Delineation of the clinical phenotype, and characteristic behaviors in a six-year-old boy

Brachmann-de Lange syndrome (BDLS) is a rare multiple congenital anomaly/mental retardation (MCA/MR) syndrome with variable expression, making diagnosis of mild cases difficult. The most consistent manifestations appear to be the characteristic face, which can be subtle in children who are mildly affected [Ireland and Burn, 1991: Twelfth Annual David W. Smith Workshop on Malformations and Morphogenesis]. Other aspects of the syndrome include variable degrees of mental retardation, growth retardation, structural abnormalities of the limbs, and behavior abnormalities, noted to be "autistic" [Jones, 1988: "Smith's recognizable patterns of human malformation"]. Johnson et al. [1976: Pediatr Res 10:843-850] described a behavior phenotype felt to be common in patients with BDLS. They predicted that patients with BDLS may respond to "behavioral intervention". Other behavior abnormalities in BDLS have been reported [Barr et al., 1971: Neuropadiatrie 3:46-66; Hawley et al., 1985: Am J Med Genet 20:453-459]. We report on a 6-year-old boy with the facial characteristics of BDLS, normal birth weight, prenatal onset of a small head relative to length, postnatal onset growth deficiency, nearly normal psychomotor development with onset of clear developmental delays by 2 years. He developed behavior problems similar to those seen in other patients with BDLS. These behaviors are most consistent with Pervasive Development Disorder-NOS (PDD), and Autistic Disorder [DSM-III-R, 1987] which encompasses a spectrum of mild to severe autistic behaviors. We report successful in-patient care utilizing medical and behavioral techniques to reduce the frequency of the behaviors. We feel that the presence of the characteristic behaviors may be helpful in confirming the diagnosis of BDLS.

Studies on requirements for amino acids in infants with disorders of amino acid metabolism. I. Effect of alanine

Two infants with disorders of propionate metabolism were studied at 7 months of age to determine optimum levels of intake of protein and calories to meet the requirements for essential amino acid for growth in infancy, and at the same time minimize the accumulation of toxic intermediates. An effect of alanine was found that permitted growth at otherwise limiting levels of protein intake. This was not simply an effect of nonessential nitrogen as neither glycine nor glutamic acid could substitute for alanine in this protein-sparing effect. This appears to represent further evidence of the relationship between alanine and the branched-chain amino acids and of the importance of the alanine-glucose cycle in human physiology.

An evaluation of protein requirements in methylmalonic acidaemia

A 3-month-old girl and a 13-month-old boy with vitamin B12-unresponsive methylmalonic acidaemia were studied to determine responses to varying levels of protein intake of growth, nitrogen balance and organic acid metabolism. A linear increase in the excretion of methylmalonic acid was observed in both patients above a critical level of protein intake. The inflection point was judged to reflect a ceiling above which amino acid intake exceeded requirements and catabolism was initiated. Below this point in each infant there was a plateau of minimal excretion of methylmalonic acid. Within this plateau level a reasonable rate of growth and metabolic stability were achieved at intakes between 0.70 and 0.75 and between 0.75 and 1.17 g protein kg-1, respectively, indicating that there is a range of protein tolerance and the importance of an individual approach to the provision of protein in patients with methylmalonic acidaemia. In the 3-month-old infant, nitrogen equilibrium was achieved at protein intakes above 0.6 g kg-1 and modest nitrogen retention was attained at a protein intake of 0.75 g kg-1, a level at which the excretion of methylmalonic acid was minimal and weight gain satisfactory. A protein intake of 1.25 g kg-1 was required to achieve a level of nitrogen retention often considered optimal for normal growth; however, this infant demonstrated an elevated excretion of methylmalonic acid and was close to clinical illness at this level of protein intake. The 13-month-old infant demonstrated a normal level of nitrogen retention, minimal excretion of methylmalonic acid, and a satisfactory rate of growth at protein intakes of 1.0-1.17 g kg-1. The values should prove useful guidelines for the management of infants requiring minimal intakes of protein. In studies carried out at 18-20 months of age, supplementation of the basic diet containing 0.75 g kg protein-1 with a mixture of amino acids not containing the precursors of methylmalonic acid was associated with increase of retention of nitrogen and increased concentrations of some essential amino acids in plasma, but effects on growth and the excretion of methylmalonic acid were not significant.

Dietary management of oculocutaneous tyrosinemia in an 11-year-old child

An 11-year-old girl with keratitis and plantar keratosis had tyrosinemia. The concentration of tyrosine in the plasma was 16.5 mg/dL. Dietary intake of phenylalanine and tyrosine was systematically varied, and the plasma concentrations of tyrosine and nitrogen balance were studied. It was necessary to achieve a total intake of phenylalanine and tyrosine less than 100 mg/kg/day to obtain plasma concentrations of tyrosine of less than 10 mg/dL. After dietary therapy was started, the keratitis resolved promptly, and the patient remained asymptomatic during a period of 16 months in which the mean plasma concentration of tyrosine was 11.1 mg/dL. The dietary management of a child at this age presents a different problem from that of a young infant. It can be successfully pursued at home, as well as in the carefully regulated environment of a clinical research center.

Lesch-Nyhan disease: clinical experience with nineteen patients

The clinical phenotype in Lesch-Nyhan disease has been analyzed in 19 patients studied in hospital. In each case the diagnosis was made on the basis of inactivity of the enzyme hypoxanthine guanine phosphoribosyltransferase in erythrocyte lysates. All had hyperuricemia, and the presence of 'orange sand' in the diaper was a prominent early complaint. All had self-mutilative behavior, of which the most characteristic form was biting the fingers or lips. All had the neurological syndrome of spasticity and choreoathetoid involuntary movements. All but one had less-than-normal intelligence.

Joseph disease and Huntington disease: protein patterns in fibroblasts and brain

Proteins were separated on two-dimensional acrylamide gels obtained from brain samples of patients with Joseph disease, Huntington disease (HD) and multiple sclerosis. Similar protein separations were made from cultured skin fibroblasts of Joseph disease patients. Two major classes of proteins, one with a MW of 50,000 probably representing the glial filamentous acidic protein, or another class with a MW of 40,000 (proteins Jc, Jd, L1 and L2) were increased in the cerebellum of six Joseph disease patients. The same protein species were abnormally increased in HD brains, mainly in the basal ganglia and frontal cortex. These identical classes of protein changes were present in two nosologically separate autosomal dominant neurological disorders, Joseph disease (a spinocerebellar degeneration) and HD (a basal ganglia and cerebral cortical degeneration) and may reflect a biochemical correlation of gliosis and neuronal disease. However, these changes may be evidence that the two diseases are allelic mutations of the same gene. The dominantly inherited spinocerebellar degenerations may result from a primary deficit of glial-neuronal interaction, resulting in neuronal loss but with a compensatory increase in the number of glial cells attempting to provide additional trophic-metabolic support.

Joseph disease: protein patterns in fibroblasts and brain

The separation of brain and fibroblast proteins was analyzed on two-dimensional acrylamide gels. Proteins were examined from skin fibroblast cultures and brain homogenates from the frontal cerebral cortex, putamen, and cerebellum. Protein species from skin fibroblast cultures of controls and patients with Joseph disease or Huntington disease were not significantly different. The proteins from homogenates of the cerebral cortex, putamen, and cerebellum from controls differed from those of one Joseph disease patient. Two major classes of proteins were increased in the patient's putamen and cerebellum. Proteins of 40,000 and 50,000 daltons--including the glial filamentous acidic protein complex (molecular weight 50,000), and two proteins which migrated near actin--were increased in the cerebellum. The glial filamentous acidic protein complex increased 3.7-fold in the putamen of the patient. These protein changes probably represent gliosis, but may also be an expression of the primary genetic mutation.

Two forms of cutis laxa presenting in the newborn period

Two infants are described with congenital cutis laxa. They represent two distinct disorders. In the first, congenital cutis laxa is associated with a generalized disorder of elastic tissue in which there may be diaphragmatic or other hernias, diverticula of the gastrointestinal or urinary tract and infantile emphysema. The disease is fatal often within the first year. In the second, congenital cutis laxa is associated with widely patent anterior fontanel, a variety of malformations, and retarded growth and development. Recognition of these distinct syndromes in the newborn period and their recessive inheritance permit realistic discussion of the prognosis which is very different from the benign dominant forms of cutis laxa.

Autosomal dominant striatonigral degeneration. A clinical, pathologic, and biochemical study of a new genetic disorder

An autosomal dominant striatonigral degeneration is present in a family of Portuguese ancestry numbering in excess of 329 persons in eight generations. The illness begins in the second, third, or fourth decade, and progresses for about 15 years with parkinsonian rigidity, spasticity, spastic dysarthria, and abnormalities of eye movement. Neuropathologic findings are severe neuronal loss and astrocytic gliosis in the corpus striatum and substantia nigra, with a moderate neuronal loss in the dentate nucleus of the cerebellum and nucleus ruber of the midbrain. This is a new genetic entity, distinct from other autosomal dominant neurologic disorders such as nigrospinodentatal degeneration, olivopontocerebellar degeneration, dystonia musculorum deformans, Machado's disease, and Huntington's disease.