Encouraging results of blood conservation in neonatal open-heart surgery

OBJECTIVE

To report early outcomes of blood conservation in neonatal open-heart surgery.

METHODS

Ninety-nine patients undergoing neonatal open-heart surgery during the implementation of a blood conservation program between May 2021 and February 2023 were reviewed. Patients either received traditional blood management (blood prime, n = 43) or received blood conservation strategies (clear prime, n = 56). Baseline characteristics and outcomes were compared between groups.

RESULTS

There was no difference in body weight (median, 3.2 kg vs 3.3 kg; P = .83), age at surgery (median, 5 days vs 5 days; P = .37), distribution of The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Categories categories or duration of cardiopulmonary bypass. Patients in the clear prime group had higher preoperative hematocrit (median, 41% vs 38%; P < .01), shorter postoperative mechanical ventilation time (median, 48 hours vs 92 hours; P = .02) and postoperative intensive care unit length of stay (median, 6 days vs 9 days; P < .01) than patients in the blood prime group. Fourteen patients (25%) in the clear prime group, including 1 Norwood patient, were discharged without any transfusion. Among patients within the clear prime group, hospitalizations without blood exposure were associated with higher preoperative hematocrit (median, 43% vs 40%; P = .02), shorter postoperative mechanical ventilation times (median, 22 hours vs 66 hours; P = .01) and shorter postoperative hospital stays (median, 10 days vs 15 days; P = .02).

CONCLUSIONS

Bloodless surgery is possible in a significant proportion of neonates undergoing open-heart surgery, including the Norwood operation, even in the early stages of experience. Early clinical results are favorable but long-term follow-up and continued efforts are warranted to prove safety and reproducibility.

Surgical Considerations in Shone Complex

Shone complex is defined by 4 anomalies: parachute mitral valve, supravalvar mitral ring, subaortic stenosis, and coarctation of the aorta. Establishing a clear definition is one of the principal challenges in the study of Shone complex as not all patients have all lesions. The essential feature of Shone complex is multilevel left-sided obstruction involving both the left ventricular inflow and outflow. This anatomic variability is reflected in the clinical presentation as signs of left ventricular inflow obstruction are often masked by outflow obstruction and the multilevel nature of the condition is thus underappreciated. Surgical treatment is often stepwise addressing the outflow obstruction first. In this review, geared to the pediatric cardiac anesthesiologist, we review the pathophysiology, diagnosis, treatment, and outcomes of Shone complex.

The Yasui operation: A single institutional experience over 30 years

Objective

The Yasui operation was introduced in 1987 for patients with 2 adequate ventricles, a ventricular septal defect, and aortic atresia or interrupted aortic arch. Despite promising early outcomes, left ventricular outflow tract obstruction (LVOTO) remains a long-term concern. The purpose of this study is to report our institutional experience with the Yasui operation.

Methods

We retrospectively reviewed all patients undergoing the Yasui operation between 1989 and 2021. Results are reported as median with interquartile range (IQR).

Results

Twenty-five patients underwent a Yasui operation (19 primary), at 11 days (IQR, 7-218 days) of life and weight of 3 kg (IQR, 2.8-4.1 days). Fundamental diagnosis was ventricular septal defect/interrupted aortic arch in 11 patients and ventricular septal defect/aortic atresia in 14. Follow-up was 96% (24 out of 25) at 5 years (IQR, 1.4-14.7) with 92% survival. Freedom from LVOTO reoperation was 91% at late follow-up with 2 patients requiring baffle revision at 6 and 9 years. Latest echocardiogram showed 100% of patients had normal biventricular function and 87% (20 out of 23) less than mild LVOTO at 5 years (IQR, 2.3-14.9). Diagnosis, aortic valve morphology, and material used were not predictors of LVOTO. Freedom from right ventricle-to-pulmonary artery conduit reoperation was 48% at a median of 5 years (IQR, 1.4-14.7). Conduit type was not a predictor of reintervention.

Conclusions

The Yasui operation can be performed with low morbidity and mortality in patients with 2 acceptable-size ventricles and aortic atresia or interrupted aortic arch with severe LVOTO. Despite some burden of reoperation, midterm reoperation for LVOTO is not common and ventricular function is preserved.

Transcriptional Profiling of Normal, Stenotic, and Regurgitant Human Aortic Valves

The genetic mechanisms underlying aortic stenosis (AS) and aortic insufficiency (AI) disease progression remain unclear. We hypothesized that normal aortic valves and those with AS or AI all exhibit unique transcriptional profiles. Normal control (NC) aortic valves were collected from non-matched donor hearts that were otherwise acceptable for transplantation (n = 5). Valves with AS or AI (n = 5, each) were collected from patients undergoing surgical aortic valve replacement. High-throughput sequencing of total RNA revealed 6438 differentially expressed genes (DEGs) for AS vs. NC, 4994 DEGs for AI vs. NC, and 2771 DEGs for AS vs. AI. Among 21 DEGs of interest, APCDD1L, CDH6, COL10A1, HBB, IBSP, KRT14, PLEKHS1, PRSS35, and TDO2 were upregulated in both AS and AI compared to NC, whereas ALDH1L1, EPHB1, GPX3, HIF3A, and KCNT1 were downregulated in both AS and AI (p < 0.05). COL11A1, H19, HIF1A, KCNJ6, PRND, and SPP1 were upregulated only in AS, and NPY was downregulated only in AS (p < 0.05). The functional network for AS clustered around ion regulation, immune regulation, and lipid homeostasis, and that for AI clustered around ERK1/2 regulation. Overall, we report transcriptional profiling data for normal human aortic valves from non-matched donor hearts that were acceptable for transplantation and demonstrated that valves with AS and AI possess unique genetic signatures. These data create a roadmap for the development of novel therapeutics to treat AS and AI.

Lecompte Procedure for Relief of Severe Airway Compression in Children With Congenital Heart Disease

PURPOSE

Children with congenital heart disease may present with severe airway compression prior to any surgical procedure or may develop airway compression following their surgical procedure. This combination of congenital heart defect and airway compression poses a significant management challenge. The purpose of this study was to review our experience with the Lecompte procedure for relief of severe airway compression.

METHODS

This was a retrospective review of ten patients who underwent a Lecompte procedure for relief of severe airway compression over the past nine years (2010-2018). Three patients with absent pulmonary valve syndrome presented with severe symptoms prior to any surgical procedure. Seven patients presented with symptoms of airway compression following repair of their congenital heart defects (one with absent pulmonary valve syndrome, three patients had repair of pulmonary atresia with ventricular septal defect, and three patients had undergone aortic arch surgery). The median age at presentation was two years (range: one day to seven years).

RESULTS

The ten patients underwent a Lecompte procedure without any significant complications or operative mortality. The median interval between the surgical procedure and extubation was 9.5 days. No patients have required any further interventions for relief of airway obstruction.

CONCLUSIONS

The Lecompte procedure is a surgical option for young children who present with severe airway compression. The patients in this series responded well to the Lecompte procedure as evidenced by clinical relief of airway compression.

Impact of Phrenic Nerve Palsy and Need for Diaphragm Plication Following Surgery for Pulmonary Atresia With Ventricular Septal Defect and Major Aortopulmonary Collaterals

Injury to the phrenic nerves may occur during surgery for pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA-VSD and MAPCAs). These patients may develop respiratory failure and require diaphragm plication. The purpose of this study was to evaluate the impact of phrenic nerve palsy on recovery following surgery for PA-VSD and MAPCAs. Between 2007 and 2016, approximately 500 patients underwent surgery for PA-VSD and MAPCAs at our institution. Twenty-four patients (4.8%) subsequently had evidence of new phrenic nerve palsy. Sixteen patients were undergoing their first surgical procedure, whereas 8 were undergoing reoperations. All 24 patients underwent diaphragm plication. A cohort of matched controls was identified based on identical diagnosis and procedures but did not sustain a phrenic nerve palsy. Eighteen of the 24 patients (75%) had clinical improvement following diaphragm plication as evidenced by the ability to undergo successful extubation (5 ± 2 days), transition out of the intensive care unit (32 ± 16 days), and discharge from the hospital (42 ± 19 days). In contrast, there were 6 patients (25%) who did not demonstrate a temporal improvement following diaphragm plication, as evidenced by intervals of 61 ± 38, 106 ± 45, and 108 ± 46 days, respectively (P < 0.05 for all 3 comparisons). The 6 patients who failed to improve following diaphragm plication had a significantly greater number of comorbidities compared to the 18 patients who demonstrated improvement (2.2 vs 0.6 per patient, P < 0.05). When compared with the control group, patients who improved following diaphragm plication spent an additional 22 days and patients who failed to improve an additional 90 days in the hospital. The data demonstrate a bifurcation of clinical outcome in patients undergoing diaphragm plication following surgery for PA-VSD and MAPCAs. This bifurcation appears to be linked to the presence or absence of other comorbidities.

Successful Operative Repair of Delayed Left Ventricle Rupture From Blunt Trauma

A 21-year-old female was found to have an enlarging pericardial effusion 10 days after a 40-foot fall. Initial cardiac evaluation was negative. Ten days after presentation she developed hemodynamic compromise and chest computed tomography was concerning for cardiac rupture. The patient was taken to the operating room where the ruptured posterior ventricle was repaired, perforation in the P1 leaflet was identified and the mitral valve was replaced. The patient survived. To our knowledge, this is the first report of survival after delayed presentation of atrioventricular rupture at the level of the mitral valve.

Pressurized Cadaver Model in Cardiothoracic Surgical Simulation

Simulation is increasingly recognized as an integral aspect of thoracic surgery education. A number of simulators have been introduced to teach component cardiothoracic skills; however, no good model exists for numerous essential skills including redo sternotomy and internal mammary artery takedown. These procedures are often relegated to thoracic surgery residents but have significant negative implications if performed incorrectly. Fresh tissue dissection is recognized as the gold standard for surgical simulation, but the lack of circulating blood volume limits surgical realism. Our aim is to describe the technique of the pressurized cadaver for use in cardiothoracic surgical procedures, focusing on internal mammary artery takedown.

High resolution manometry sub-classification of Achalasia: does it really matter? Does Achalasia sub-classification matter?

BACKGROUND

Three variants of Achalasia have been described using high-resolution esophageal manometry (HRM). While manometrically distinct, their clinical significance has yet to be established. Our objective was to compare the outcome after myotomy in patients with these Achalasia subtypes.

METHODS

A retrospective chart review was performed to identify patients with Achalasia who had HRM and who underwent Heller myotomy or Per oral endoscopic myotomy (POEM). Symptoms and esophageal clearance by timed barium study were compared before and after treatment.

RESULTS

We identified 49 patients, 21 males and 28 females, with a median age of 52 years. The primary symptom in all patients was dysphagia, with a median duration of 4 years (range 4 months-50 years). By HRM, ten patients (20 %) were classified as Type I, 30 (61 %) as Type II, and 9 (18 %) as Type III. At a median follow-up of 16 months after myotomy (range 1-63 months), the median Eckardt score was zero and was similar across subtypes. Relief of dysphagia was also similar across subtypes (80 % of Type I, 93 % of Type II and 89 % of Type III). On pre-treatment timed barium study, no patient had complete emptying at 1 or 5 min. After myotomy, complete emptying occurred within 1 min in 50 % (20/40) and within 5 min in 60 % (24/40) and was similar across groups.

CONCLUSION

Myotomy for Achalasia results in excellent symptomatic outcome and improvement in esophageal clearance. There was no difference among the described HRM Achalasia variants. This calls into question the clinical utility of Achalasia sub-classification and affirms the benefit of myotomy for this disease.

Acute esophageal necrosis: a case series and long-term follow-up

Acute esophageal necrosis (AEN) is a rare condition characterized by circumferential necrosis of varying lengths in the intrathoracic esophagus. Endoscopically, this process is manifested as a black esophagus. To date, limited case series exist describing AEN, and none report long-term follow-up. Our objective was to report 3 patients with AEN, all diagnosed within 1 year at a tertiary academic medical center, describing early and long-term outcomes of this rare disease. In the absence of perforation, patients can be managed conservatively with serial esophagogastroduodenoscopy (EGD). Long-term strictures may occur that require dilation.

Long-term quality of life and alimentary satisfaction after esophagectomy with colon interposition

BACKGROUND

The long-term outcome after colon interposition for esophageal reconstruction is not well documented. Our objective was to assess quality of life and alimentary satisfaction 10 or more years after colon interposition.

METHODS

Patients who had an esophagectomy that was reconstructed using a colon interposition before April 2003 were identified. Symptoms, alimentary satisfaction, and quality of life were assessed by telephone interview and questionnaires.

RESULTS

We identified 79 surviving patients, and follow-up was obtained in 63 (80%). The indication for esophagectomy was cancer in 45 patients and benign disease in 18. Vagal-sparing esophagectomy was performed in 48% of patients, en bloc in 44%, and transhiatal in 8%. Median follow-up was 13 years (range, 10 to 38 years). The median Gastrointestinal Quality of Life Index score was 3 of 4 and results from the RAND 36-Item Short Form Health Survey (RAND Corp, Santa Monica, CA) were at or above the published normal means in all categories. Most patients were free of dysphagia (89%), regurgitation (84%), and heartburn (84%). The most common postprandial symptom was early satiety (40%). The body mass index was within normal reference ranges in 90% of patients. Follow-up esophagogastroduodenoscopy in 30 patients at a median of 6 years showed no Barrett's metaplasia in the residual esophagus. Seven patients had a reoperation for colon redundancy.

CONCLUSIONS

Long-term alimentary satisfaction and quality of life were excellent after colon interposition. Most patients were free of dysphagia and few needed revision for redundancy. These results should encourage the use of a colon interposition in patients expected to survive long-term after esophagectomy.

Endoscopic ultrasound staging of stenotic esophageal cancers may be unnecessary to determine the need for neoadjuvant therapy

INTRODUCTION

Endoscopic ultrasound (EUS) is an essential component of preoperative staging for esophageal cancer and is used to determine which patients should proceed to primary surgical resection or receive neoadjuvant therapy prior to surgery. However, when the EUS scope cannot traverse a tumor, the role of pre-dilatation is controversial due to the risk of perforation.

METHODS

A retrospective review was conducted of all patients with esophageal tumor stenosis that could not accommodate the EUS scope who then proceeded with primary esophagectomy. The pathology results were classified based on the revised seventh edition American Joint Committee on Cancer staging system.

RESULTS

A total of 27 patients met inclusion criteria. The majority of tumors were T3 (24/27, 89 %). There were no stage I tumors, 15 % (4/27) were stage II, 81 % (22/27) were stage III, and 4 % (1/27) were stage IV due to a resected solitary lung metastasis.

CONCLUSION

Tumors that cannot be assessed with an EUS scope due to tumor stenosis will have locally advanced disease in the majority of cases. In these situations, pre-dilatation of the tumor with EUS staging should be omitted when considering the risk of potential esophageal perforation and the patients should be referred for neoadjuvant therapy.

Markedly elevated serum biotinidase activity may indicate glycogen storage disease type Ia

We report two children who presented with symptoms suggestive of biotinidase deficiency. Rather than deficiency, markedly elevated serum biotinidase activities were found. Based upon literature reports of elevated biotinidase activities in children with glycogen storage disease (GSD) type Ia, we considered the latter in our differential diagnosis and subsequently confirmed GSD type Ia in both patients by enzymatic testing. GSD type Ia should be considered in children with markedly elevated serum biotinidase activity.

GABA receptor antagonists modulate postmitotic cell migration in slice cultures of embryonic rat cortex

Recent studies indicate that GABA acts as a chemoattractant during rat cortical histogenesis. In vivo, GABA localizes in appropriate locations for a chemoattractant, along migratory routes and near target destinations for migrating cortical neurons. In vitro, GABA induces dissociated embryonic cortical neurons to migrate. Here, embryonic rat cortical slices were cultured in the presence or absence of GABA receptor (GABA-R) antagonists to assess GABA's effects on neuronal migration in situ. Gestational day 18 (E18) cortical slices were incubated overnight in bromodeoxyuridine (BrdU)-containing medium to label ventricular zone (vz) cells as they underwent terminal mitosis. The slices were then cultured in BrdU-free medium with or without GABA-R antagonists. In control slices, most BrdU(+) cells were observed in the cortical plate (cp) after 48 h. In contrast, cultures maintained in either saclofen (a GABA(B)-R antagonist) or picrotoxin (a GABA(A/C)-R antagonist) had few BrdU-labeled cp cells. However, the effects of the two antagonists were distinct. In the picrotoxin-treated slices, nearly half of all BrdU(+) cells remained in the vz and subventricular zone (svz), whereas saclofen treatment resulted in an accumulation of BrdU(+) cells in the intermediate zone (iz). Bicuculline, a GABA(A)-R antagonist, did not block, but rather enhanced migration of BrdU(+) cells into the cp. These results provide evidence that picrotoxin-sensitive receptors promote the migration of vz/svz cells into the iz, while saclofen-sensitive receptors signal cells to migrate into the cp. Thus, as cortical cells differentiate, changing receptor expression appears to modulate migratory responses to GABA.

Glutamate acting at NMDA receptors stimulates embryonic cortical neuronal migration

During cortical development, embryonic neurons migrate from germinal zones near the ventricle into the cortical plate, where they organize into layers. Mechanisms that direct neuronal migration may include molecules that act as chemoattractants. In rats, GABA, which localizes near the target destination for migrating cortical neurons, stimulates embryonic neuronal migration in vitro. In mice, glutamate is highly localized near the target destinations for migrating cortical neurons. Glutamate-induced migration of murine embryonic cortical cells was evaluated in cell dissociates and cortical slice cultures. In dissociates, the chemotropic effects of glutamate were 10-fold greater than the effects of GABA, demonstrating that for murine cortical cells, glutamate is a more potent chemoattractant than GABA. Thus, cortical chemoattractants appear to differ between species. Micromolar glutamate stimulated neuronal chemotaxis that was mimicked by microM NMDA but not by other ionotropic glutamate receptor agonists (AMPA, kainate, quisqualate). Responding cells were primarily derived from immature cortical regions [ventricular zone (vz)/subventricular zone (svz)]. Bromodeoxyuridine (BrdU) pulse labeling of cortical slices cultured in NMDA antagonists (microM MK801 or APV) revealed that antagonist exposure blocked the migration of BrdU-positive cells from the vz/svz into the cortical plate. PCR confirmed the presence of NMDA receptor expression in vz/svz cells, whereas electrophysiology and Ca2+ imaging demonstrated that vz/svz cells exhibited physiological responses to NMDA. These studies indicate that, in mice, glutamate may serve as a chemoattractant for neurons in the developing cortex, signaling cells to migrate into the cortical plate via NMDA receptor activation.

Catastrophic metabolic encephalopathies in the newborn period. Evaluation and management

The newborn who presents with neurologic symptoms such as seizures or lethargy due to inborn error of metabolism is an important problem. Although each inborn error that presents in this manner is rare, these conditions are not rare as a group, and more than one in 1000 babies is affected with one of the more than 100 different inborn errors that are now known. Many of these conditions present with much the same features seen in sepsis or asphyxia and, when untreated, can lead rapidly to death or permanent neurologic damage. Early diagnosis and management may prevent some or all of this morbidity, and also permits the parents to be informed about the chances of having other affected children. Despite the large number and complexity, most metabolic encephalopathies can be diagnosed by applying a few simple clinical principles and laboratory tests. These principles, and the typical features of some inborn errors that present in the neonate, are detailed in this article.

Treatment of Smith-Lemli-Opitz syndrome: results of a multicenter trial

Patients with the RSH or Smith-Lemli-Optiz syndrome (SLOS) have an inborn error of cholesterol biosynthesis which results in a deficiency of cholesterol and an elevation of the cholesterol precursor, 7-dehydrocholesterol. A treatment protocol consisting of administration of cholesterol +/- bile acids was initiated in an attempt to correct the biochemical abnormalities seen. Fourteen patients (8 female, 6 male: ages 2 months to 15 years) have now been treated for 6-15 months. Three patients received cholesterol alone, while 11 patients received cholesterol and one or more bile acids. Biochemical improvement in sterol levels and in the ratio of cholesterol to total sterols was noted in all patients. The most marked improvement was noted in patients presenting with initial cholesterol levels < 40 mg/dl. No toxicity was observed. Clinical improvement in growth and neurodevelopmental status was also observed.

Radiocephalometric evaluation of a family with mandibulofacial dysostosis

Persons from four generations of a family with mandibulofacial dysostosis (MFD), known as Treacher Collins (TC) Syndrome, were examined for the presence of clinical signs traditionally associated with this syndrome. In this family, 14 adults, who had been judged trait bearers by an earlier family study were included in this study. Maxillary and mandibular study models were taken of affected and unaffected family members. Panoramic cephalograms and lateral radiographs were taken. The lateral cephalograms were traced and digitized on a computer system and compared. The 117 cephalometric values of the trait bearers were compared with known standard values and nontrait bearing family members. In the trait bearing group, 81 of the 117 values and, in the nontrait bearing group, 72 of the 117 values were significantly different (p < 0.05) when comparing mean values to the accepted normal range. The interfamily comparison between trait-bearing and nontrait members revealed nine values to be significantly different. This indicates that cephalometric analysis of these patients, some of whom have minimal clinical expression of the gene, may have potential value for screening and further characterization of this condition. The results also suggest that intrafamily comparisons may be of greater value for diagnostic confirmation of TC than comparison with literature norms.

Intrafamilial variability in Hurler syndrome and Sanfilippo syndrome type A: implications for evaluation of new therapies

Intrafamilial variability has not been reported previously in Hurler syndrome or Sanfilippo syndrome type A. We describe two families in which sibs with comparable deficiencies of alpha-iduronidase (Hurler) or sulfamidase (Sanfilippo type A) activities in vitro nonetheless have divergence in clinical severity and disease progression. These cases underscore the need for caution in counseling as well as the limitations of using sibs as controls in evaluating the outcome of treatment.

Molybdenum cofactor deficiency

We describe a new case of molybdenum cofactor deficiency, an underrecognized inborn error of metabolism that results in neonatal seizures and neurologic abnormalities. Characteristic biochemical defects in affected individuals include hypouricemia, elevated urine sulfate (detectable by dipstick), and elevated S-sulfocysteine (detectable by anion exchange chromatography). This disorder should be considered in the differential diagnosis of neonatal seizures.

Mutation in the 4a-carbinolamine dehydratase gene leads to mild hyperphenylalaninemia with defective cofactor metabolism

Hyperphenylalaninemias represent a major class of inherited metabolic disorders. They are most often caused by mutations in the phenylalanine hydroxylase gene and, less frequently but with usually more serious consequences, in genes necessary for the synthesis and regeneration of the cofactor, tetrahydrobiopterin. This cofactor is absolutely required for all aromatic amino acid hydroxylations, and, recently, nitric oxide production from L-arginine has also been found to be dependent on tetrahydrobiopterin. Phenylalanine hydroxylase catalyzes a coupled reaction in which phenylalanine is converted to tyrosine and in which tetrahydrobiopterin is converted to the unstable carbinolamine, 4a-hydroxytetrahydrobiopterin. The enzyme, carbinolamine dehydratase, catalyzes the dehydration of the carbinolamine to quinonoid dihydropterin. A decreased rate of dehydration of this compound has been hypothesized to be responsible for the production of 7-biopterin found in certain mildly hyperphenylalaninemic individuals. We have now identified nonsense and missense mutations in the 4a-carbinolamine dehydratase gene in a hyperphenylalaninemic child who excretes large amounts of 7-biopterin. This finding is consistent with the role of the carbinolamine dehydratase in the phenylalanine hydroxylation reaction. Together with previously identified inherited disorders in phenylalanine hydroxylase and dihydropteridine reductase, there are now identified mutations in the three enzymes involved in the phenylalanine hydroxylation system. In addition, the genetics of this system may have broader implications, since the product of the dehydratase gene has previously been shown to play an additional role (as dimerization cofactor for hepatocyte nuclear factor-1 alpha) in the regulation of transcription, through interaction with hepatocyte nuclear factor-1 alpha.

Update on inborn errors of metabolism: primary lactic acidemia

Initially thought to be rare, primary lactic acidemia is diagnosed with increasing frequency. Elevations in lactate and pyruvate are markers for a variety of metabolic blocks. Although there have been great strides made in the diagnosis and treatment of lactic acidemia, much remains to be learned. As laboratory techniques improve, clinicians will be able to make an exact enzymatic diagnosis on an increasing percentage of patients. Specific enzymatic diagnosis also will help clinicians determine inheritance patterns, recurrence risks, and methods of prenatal diagnosis.

Hyperuricemia in medium-chain acyl-coenzyme A dehydrogenase deficiency

Six infants and children with medium-chain acyl-coenzyme A dehydrogenase deficiency were found to have hyperuricemia during an acute episode. Hyperuricemia may be a clue to the diagnosis of medium-chain acyl-coenzyme A dehydrogenase deficiency.

Maternal phenylketonuria and hyperphenylalaninemia: implications for medical practice in the United States

The risk of maternal phenylketonuria and hyperphenylalaninemia syndrome, a preventable cause of severe birth defects and retardation with a near 100% recurrence risk if untreated, is increasing in the United States. The reasons for this are reviewed. Women with hyperphenylalaninemia and those with phenylketonuria diagnosed and treated at birth are intellectually normal, as are some women with undiagnosed phenylketonuria. Both groups are at risk for maternal phenylketonuria syndrome in their offspring if blood phenylalanine levels are not controlled by diet during pregnancy. The problems and pitfalls of suspecting, diagnosing, and managing the condition are discussed. Suggested strategies for reversing the increasing trend include the greater use of genetic registers, increased clinical awareness, and some form of rescreening. The advantages and costs of rescreening a subset of pregnant women or all pregnant women at or before their first registration are examined.

A rapid method for spin-drying large quantities of cytofunnels

A centrifugal spinner designed for drying lettuce leaves has been found to facilitate rapid drying of large quantities of cytofunnels.

3-Hydroxy-3-methylglutaryl-coenzyme A lyase deficiency: report of five new patients

Five new patients are reported and the pathogenesis of the hypoglycaemia without ketogenesis is discussed. This report extends a recent review.

3-Hydroxy-3-methylglutaric aciduria

3-Hydroxy-3-methylglutaric aciduria was found in a newborn infant whose parents are first cousins. The patient presented at 5 days of life with hyperammonemia, hypoglycemia, and metabolic acidosis. There was no ketonuria. Diagnosis was made by analysis of the pattern of organic acids excreted in the urine. A profound deficiency in activity of 3-hydroxy-3-methylglutaryl-coenzyme A lyase was found in cultured skin fibroblasts. The parents had intermediate levels of enzyme activity.