Efficacy of Feeding Pump for Patients on Enteral Tube Feeding: A Systematic Literature Review and Analysis / 대한소화기학회지

BACKGROUND/AIMS: This study was conducted to establish a guideline on the utilizing of feeding pump in patients requiring enteral tube feeding. METHODS: As a first step, textbooks on nutrition and guidelines from regional clinical nutrition societies were analyzed. Afterwards, data on the efficacy, safety, and practicality of feeding pump application were collected and evaluated by systematically reviewing the related literature. As data sources, 8 domestic databases including KoreaMed and global databases such as Ovid-MEDLINE, Ovid-EMBASE, and Cochrane Library were utilized. A total of 2,016 related articles was selected by applying the keyword "(enteral feeding.mp AND pump.mp)". RESULTS: Textbooks and guidelines were not able to draw conclusions on the effects of the feeding pump because the injection speed, tube size, and etcetera were different for enteral feeding. Feeding pump assisted enteral tube feeding was an efficient, safe, and practical procedure for reducing maladjustment-related complications of enteral tube feeding, which are obvious obstacles for maintaining nutritional balances in patients requiring tube feeding. CONCLUSIONS: Feeding pump application can be considered an efficient and safe measure that is acceptable in patients on small intestinal tube feeding, critically-ill patients on gastro-intestinal tube feeding, premature babies, and critically-ill or severely malnourished children (recommendation grade D).

Biliary Pseudolithiasis in Children: To Avoid Unnecessary Surgical Procedure / 소아외과

Gallbladder stones in children are not common without underlying hemolytic diseases or other risk factors like obesity. Ceftriaxone, a third generation cephalosporin, is known to make biliary precipitations that can be mistaken for biliary stones. We here report two children with biliary pseudolithiasis with different treatment modalities. One child was mistaken for symptomatic gallbladder stones and underwent elective laparoscopic cholecystectomy, while the other child, after thorough history taking on the ceftriaxone medication, was suspected of biliary pseudolithiasis and was treated conservatively. Both children had the history of usage of ceftriaxone in previous hospitals for infectious diseases. The ceftriaxone history of the first child was missed before the surgery. When gallbladder stones are found in children without any underlying diseases, specific history taking of the usage of ceftriaxone seems to be absolutely required. In this case, immediate interruption of the antibiotic could resolve the episode and avoid unnecessary surgical procedure.

Management Strategies for Patients with Chronic Intestinal Failure Who Are Potential Candidates for a Future Intestinal Transplant / 대한이식학회지

Intestinal transplant wait-list mortality is higher than for other organ transplants. This is a review to identify the main problems contributing to the high risk of intestinal transplant candidates and to provide recommendations on how to resolve them. Intestinal transplant, home parenteral nutrition, and intestinal rehabilitation articles issued from the main intestinal transplantation centers from 1987 to 2010 were reviewed. The risk factors for adult and child transplant wait-list mortality were parallel to those of parenteral nutrition. Therefore, primary care givers managing patients with intestinal failure should establish a cooperative link to facilities with active intestinal failure programs from the early period, when anticipation for the parenteral nutrition (PN) requirement is more than 50% in the 3 months of initiation. An intestinal failure care program should include or establish an active collaborative relationship with centers performing intestinal rehabilitation and transplantation. Intestinal rehabilitation centers are expected to establish a multiprofessional team composed of medical doctors, nurses, pharmacists, dieticians, surgeons, gastroenterologists, social workers, fund managers, PN-solution providers, and intestinal transplantation surgeons. National registries for patients undergoing intestinal failure should be established, and home-PN providers should participate.

Two Cases of Pneumocystis Pneumonia after Liver Transplantation Presenting with Different Clinical Manifestations / 대한이식학회지

Pneumocystis carinii pneumonia (PCP), now known as Pneumocystis jirovecii, is a fungal pathogen that causes opportunistic disease, especially pneumonia, in immunocompromised patients. The patients can have a spectrum of illnesses ranging from asymptomatic to fulminant respiratory failure. Here we report two cases with pneumocystis pneumonia after liver transplantation who presented with different clinical features. One patient developed acute respiratory failure requiring mechanical ventilation and expired due to PCP and a superimposed bacterial infection. The other patient was asymptomatic and discovered by regular X-ray check-up. He was successfully treated with trimethoprim/sulfamethoxazole. As shown by our cases, PCP presents with broad clinical manifestations and leads to various clinical courses in liver transplant recipients. Thus, Pneumocystis jirovecii has to be considered a potential pathogen of pneumonia in liver transplant recipients regardless of severity, especially one who is not on prophylactic medications. We consider prophylaxis of PCP in liver transplant recipients in our center.

Epidemiology and Risk Factors for Bacteremia in 144 Consecutive Living-Donor Liver Transplant Recipients

PURPOSE: Bacteremia is a major infectious complication associated with mortality in liver transplant recipients. The causative organisms and clinical courses differ between medical centers due to variations in regional bacterial epidemiology and posttransplant care. Further, living donors in Korea contribute to 83% of liver transplants, and individualized data are required to improve survival rates. PATIENTS AND METHODS: We retrospectively analyzed 104 subjects who had undergone living-donor liver transplant from 2005 to 2007. RESULTS: Among the 144 consecutive living-donor liver transplant recipients, 24% (34/144) developed bacteremia, 32% (46/144) developed non-bacteremic infections, and 44% (64/144) did not develop any infectious complications. Forty episodes of bacteremia occurred in 34 recipients. The major sources of bacteremia were intravascular catheter (30%; 12/40), biliary tract (30%; 12/40), and abdomen (22.5%; 9/40). Gram-positive cocci were more common (57.5%; 23/40) than Gram-negative rods (32.5 %; 13/40) and fungi (10%; 4/40). The data revealed that the following factors were significantly different between the bacteremia, non-bacteremic infection, and no infection groups: age (p = 0.024), posttransplant hemodialysis (p = 0.002), ICU stay (p = 0.012), posttransplant hospitalization (p < 0.0001), and duration of catheterization (p < 0.0001). The risk factors for bacteremia were older than 55 years (odds ratio, 6.1; p = 0.003), catheterization for more than 22 days (odds ratio, 4.0; p = 0.009), UNOS class IIA (odds ratio, 6.6; p = 0.039), and posttransplant hemodialysis (odds ratio, 23.1; p = 0.001). One-year survival rates in the bacteremic, non-bacteremic infection, and no infection groups were 73.2%, 91.3%, and 93.5%, respectively. CONCLUSION: Early catheter removal and preservation of renal function should focus for improving survival after transplant.

Clinical Outcome of Pretransplant Renal Dysfunction in Adult Living Donor Liver Transplantation / 대한이식학회지

BACKGROUND: The aim of this study is to analyze the clinical significance of preoperative renal dysfunction in patients with living donor liver transplant (LDLT). METHODS: We analyzed data collected retrospectively from 327 consecutive LDLT performed at Department of Surgery, Catholic University of Korea from Jan. 2000 to Dec. 2007. Based on creatinine clearance rate (CCR) calculated before LDLT, the patients were classified in three groups: normal renal function(CCR > or =70 ml/min, 273 patients, 83.5%), mild renal dysfunction (CCR or =40 ml/min, 38 patients, 11.6%) and severe renal dysfunction (CCR1.5 mg/dl) was up to 46.2%. Even in patient with normal renal function, the incidence of postoperative hemodialysis and renal dysfunction 3 months postoperatively was about 5%. Multivariate analysis showed that preoperative serum creatinine, MELD score and postoperative diabetes predicted postoperative renal dysfunction. There was no statistical difference in survival curve between normal and mild renal dysfunction group but the patient with severe renal dysfunction showed worse survival compare with other groups (P < 0.001). CONCLUSIONS: Our data suggested that the patient with preoperative severe renal dysfunction have had poor recovery of renal dysfunction and high incidence of hemodialysis postoperatively and showed worse survival rate after transplantation.

The Usefulness of Salvage Transplantation in Patients with Hepatocellular Carcinoma / 대한이식학회지

PURPOSE: The treatment of choice for hepatocellular carcinoma (HCC) is either surgical resection or liver transplantation. Liver transplantation has the advantage of treating both the tumor and cirrhosis at the same time. However, due to the shortage of donors the availability of this treatment modality is limited. When recurrence is found after liver resection, liver transplantation (salvage transplantation) is an alternative treatment option, as well as in cases with hepatic failure after resection. We carried out this study to evaluate the usefulness of salvage transplantation in these cases. METHODS: From October 2000 to September 2007, among 305 patients who underwent living donor liver transplantation at Kangnam St. Mary Hospital, 119 underwent liver transplantation for HCC. Among them, 102 patients received a primary liver transplantation (PT) and 17 salvage liver transplantation (ST). Among those who underwent a ST, 7 had a major liver resection and 10 had a minor resection, prior to the transplantation. During the ST, all patients received right lobe grafts from living donors. Preoperative and postoperative clinical data were analyzed, as well as survival and disease free survival between the PT and ST groups. RESULTS: There were 5 cases (4.9%) of perioperative mortality in the PT group and 3 cases (17.7%) in the ST group; this difference was without statistical significance. The transfusion requirement for red blood cells was greater in the ST group; but this difference did not reach statistical significance (13.5+/-8.5 units in PT vs. 17.9+/-8.5 units in ST). In addition, there were no significant differences in the recipient operation time (640+/-111 mins in PT vs. 751+/-145 mins in ST), postoperative complication rate (32.3 % in PT vs. 58.8% in ST), reoperation rate (7.8 % in PT vs. 5.9% in ST), and postoperative hospital stay (30.9+/-9.9 days in PT vs. 29.2+/-11.5 days in ST). Furthermore, the 3- and 5-year intention to treat overall survival rate (70.0%, 65.1% in PT vs. 82.4%, 76.0% in ST) were not significantly different. CONCLUSION: The overall survival and disease free survival rates after ST were similar to those after PT. Salvage transplantation, therefore, may be a useful rescue therapy for patients that develop disease recurrence or deterioration of liver function after liver resection for HCC.

Cryptosporidiosis in a Small Bowel Transplant Recipient / 대한이식학회지

No abstract available.

Epidemiological Data on Antibiotic-resistant Bacteria Isolated in Liver Transplant Recipients / 대한이식학회지

BACKGROUND: Post-transplant infections by antibiotic-resistant bacteria (ARB) are increasing in prevalence because of the wide use of broad-spectrum antibiotics. At our center, the perioperative prophylaxis for liver transplant recipients consistes of cefoperazone/sulbactam and ampicillin. When the recipient develops signs of infection, the initial antibiotics are empirically replaced with meropenem and vancomycin. We analyzed the epidemiology of ARB to assess the appropriateness of replacing empirical antibiotics during the first month after liver transplantation. METHODS: We reviewed 88 patients who had undergone living donor liver transplant between January 2006 and September 2007. RESULTS: Two hundred and seventy-six strains of bacteria were microbiologically documented in 75 liver transplant recipients. The most common bacteria was Staphylocococcus aureus (27%), followed by coagulase-negative staphylococci (CNS, 20%), Enterococcus species (18%) and Klebsiella species (7%). Our data on the resistance pattern showed that 87.8% and 71.4% of the S. aureus and CNS were resistant to methicillin, respectively; 88% of the Enterococcus species were resistant to ampicillin and 24% to vancomycin; and 62% of all enteric gram-negative bacilli (GNB) were resistant to 3rd generation cephalosporins. No strains of meropenem-resistant GNB were detected. Only one glucose non-fermentative GNB was resistant to all antibiotics except aminoglyco sides and colistin. CONCLUSIONS: Mainly methicillin-resistant gram- positive bacterial strains, including S. aureus and CNS, can colonize in early period after transplantation. According to the epidemiologic data on the high prevalence of antibiotic-resistant organisms, the empirical treatment regimen at our center is considered as appropriate. However, shifting down to less-broad-spectrum antibiotics after the pathogens are confirmed is essential to lowering the rate of ARB.

Outcome and Risk Factor of Early Recurrence of Hepatocellular Carcinoma after Liver Transplantation and Effect of Pre-transplant Transarterial chemoembolization on Post-transplant Outcome

PURPOSE: The aims of this study were to find the risk factor and outcomes of patients with an early recurrence (ER) of a hepatocellular carcinoma (HCC) after liver transplantation (LT) and the actual impact of transarterial chemoembolization (TACE) before LT for a HCC on patient survival and HCC recurrence. METHODS: Ninety-eight cases of adult LT, performed between September 1995 and January 2006, were evaluated. The risk factors and prognosis of patient with a HCC after transplantation for an ER, defined as a recurrence within 6 months of transplantation, and the effects of Pre-LT TACE on the disease-free and overall survival rates, as well as the patterns of recurrence after LT, were studied. RESULTS: A total of 18 patients (18.4%) experienced a HCC recurrence after LT; 10 and 8 patients had early and late recurrences, respectively. From a univariate analysis, the serum alpha-fetoprotein (P=0.003), tumor size (P=0.003), serosa invasion (P=0.000), tumor grade (P=0.011) and vascular invasion (P=0.014) were statistically significant risk factors for an ER. From a multivariate analysis, the presence of serosa invasion of a HCC was the only independent risk factor for an ER (P=0.009; OR=9.407: 95% CI, 1.764~50.164). There was no difference in the disease free sur-vival and overall survival rates between the TACE and without TACE groups, but the extrahepatic recurrence rate was higher in the TACE than without TACE group. CONCLUSION: Serosa invasion by a HCC is independently associated with an ER of HCC after LT. Pre-LT TACE does not influence the disease-free and overall survivals after LT for a HCC.

Clinical Outcome of Preoperative Portal Vein Thrombosis in Living Donor Liver Transplantation / 대한이식학회지

PURPOSE: Portal vein thrombosis (PVT), which once had been considered a relative contraindication for living donor liver transplantation (LDLT), is no longer contraindication of LDLT owing to technical achievement but could be remained as one of risk factor affecting patients. The aim of the present study was to improving outcomes of LDLT of patients with PVT by analyzing patients with PVT. METHODS: Between January 2000 and May 2006, 246 cases of LDLT in adult using right lobe were performed. The presence of PVT was preoperatively evaluated by CT and/or MR angiography. The patients were subdivided according to presence and characteristics of PVT; No PVT (n=196; 79.7%), Partial PVT (n=39; 15.9%) and Total PVT (n=11; 4.4%) and characteristics of each group were analyzed. RESULTS: Preoperatively, only the incidence of variceal bleeding was significantly higher in patients with PVT (P<05). Intraoperatively, larger amounts of transfused RBC were needed in PVT group and postoperatively, there were prolonged stay in ICU and higher incidence of hemorrhagic complications in PVT group. Portal inflow was reestablished by thrombectomy and end-to-end anastomosis without vessel graft in 97.4%(38/39) of partial PVT and in 54.5%(6/11) of total PVT. Cryopreserved veins were used as interposition (n=1) or jump (n=4) grafts and an autologous iliac vein was used as a jump graft (n=1). Of 5 cases of jump grafts, 2 cases were anastomosed to coronary vein, and 3 cases to superior mesenteric vein. The patency rate using vessel grafts was 83.3%(5/6) and overall patency rate including thrombectomy cases was 98.0%(39/40). CONCLUSION: Regardless of operative methods and materials, higher patency rate of portal vein could be achieved so that operation of patients with PVT could be undertaken safely without increased mortality.

Isolated Small Bowel Transplantation from a Living-Related Donor at the Catholic University of Korea: A Case Report of Rejection - Free Course -

The bowel transplantation team at the Catholic Medical Center, Korea, on April 9 2004, accomplished a case of isolated small bowel transplantation (SBT) in a 57 year-old female with short bowel syndrome. The primary surgery was a jejunocolostomy due to mesenteric vein thrombosis, while maintaining 30 cm of the jejunum and colon distal to the splenic flexure. Her renal function was partially unbalanced. During more than 2 years of home TPN, the superior vena cava (VC) and subclavian veins had become occluded, but the inferior VC line remained. SBT was planned due to the repeated life-threatening infections of the last central line. One hundred and fifty centimeter of the distal ileum of the 27 year-old living-related donor, the patient's daughter, was harvested. The graft mesenteric artery and vein were anastomosed to the recipient's inferior mesenteric vessels. A proximal end- to-end jejuno-ileostomy and a distal end-to-side ileo-colostomy of the graft were made, creating a Bishop-Koop enterostomy for graft surveillance. A tube jejunostomy, via a gastrostomy, was established for early feeding and simultaneous gastric drainage. Induction with Daclizumab and immunosuppression consisted of tacrolimus and methylprednisolone, given intravenously, and then mycophenolate mofetil (MMF), enterally from day 3. The patient was discharged on day 42. A CMV infection on day 83 was successfully treated with 3 weeks of gancyclovir therapy. She has been nutritionally independent, with complete oral feeding, and free of rejection until day 170 after the transplantation.

Nutritional Support

Nutritional support is one of the major advances in the history of medicine in the 20th century. Since Dudrick and associates (1968) achieved the first successful nutritional support in puppies and human infants with short bowel syndrome, this technology has expanded as a gospel throughout the world. We can supply almost all of the macro-and-micro-nutrients and calories as much as we need. However, utilities of some specific nutrients have to be limited only by the defined metabolism and the pathophysiology under the concept of nutritional pharmacology. This paper is for a practical review of the nutritional support for physicians who are working in the primary and secondary care centers in this country.

Lipomatous Lesion of the Spermatic Cord and Pediatric Inguinal Hernia

A lipomatous lesion of the cord is an accidentally encountered structure during the operative repair of inguinal hernia. This lesion has been reported as a lipoma of the cord in adults. However, there is only a limited number of reports in the pediatric age group. To evaluate the prevalence of this lesion in children and in order to review the surgical significancies, 600 hernia operations in 411 children during a period of 4 years from January, 2000 to December, 2003 in the Division of Pediatric Surgery, Department of Surgery, the Catholic University of Korea, were included in this study. There was a total of 31 (5.2%) lipomatous lesions in 25 (6.1%) cases; 3 cases in infants, 17 between 1 to 4 years, and 5 above 5 years of age. Male was more prevalent (male to female ratio 14:11). The laterality of clinical hernia with the lesions was 10 in the right, 13 in the left and 2 in both sides. The patients with ipsilateral lesions to the hernia were 14, contralateral in 5 and bilateral in 6 cases. Excluding 1 case of bilateral lesions in bilateral hernia, 10 lesions were contralateral to the clinical hernias. In 1 case, lipomatous lesion was the sole finding with nonsignificant patent processus vaginalis. Every lesion was suture ligated and resected with gentle traction of the dissected hernia sac. It has not been clearly defined whether the lesion is a stopper or a provocator of the hernia development. However, removal is highly recommended to make a differential diagnosis from the recurrent inguinal hernia in future. The term "lipomatous lesion" seems to be pathologically accurate and must be differentiate from the true lipomas.

Donor Safety in Living Donor Liver Transplantation Using Right Lobe / 대한이식학회지

PURPOSE: Right lobe donation is technically more difficult and need to define surgical technique and has more risk for surgical complication. Right lobe donation usually matched graft size but safety of donor is major concern. In this paper, we reviewed our experience of donor hepatectomy using right lobe in regarding to safe of our donor operations, retrospectively. METHODS: Retrospective analysis of 42 donor operations for adult LDLT using right lobe was performed. We observed the patient characteristics, the operative findings, peak liver enzymes (AST, ALT, bilirubin) as donor risk and mortality, morbidity. RESULTS: The peak value of liver enzymes in the group of less the 30% of remained liver were significantly higher than the group of more than 30% of remained liver and these values could induced the risk on donor. The postoperative peak value of liver enzymes were increased according to degree of fatty change especially in case of more than 10% fatty change even without significance. We observed the liver regeneration on postoperative 3 months and the regeneration of liver volume on postoperative 3 months was about two times compare to preoperative value and the regenerative activity was more increased in the group of less amount of remained volume. There was no donor mortality and most important complication was biliary complication, in which were biliary injury, bile leakage and biliary stricture. CONCLUSION: Right lobectomy for donor operation requires a meticulous surgical technique to minimize donor morbidity. Right lobectomy can be performed safely with minimal risk in case of careful donor selection that the remained liver volume exceed 30% of the total liver volume and the liver of minimal fatty change.

Glutamine on the Luminal Microbial Environment After Massive Small Bowel Resection

To evaluate the oral glutamine (GLN) on the luminal microbes and bacterial translocation (BT) in short bowel, 45 Wistar rats were utilized in three groups; A (control), and B and C (short bowel, 85% of small bowel resected). The group A was fed with elemental diet (EmD), B with EmD+2% glycine, and C with EmD+2% GLN. The groups B and C were isocaloric and isonitrogenous. Wet weight, DNA, protein, and histomorphometry of the mucosa and parallel microbial culture from cecal contents, caval blood, and tissue blocks of the liver, spleen, and mesenteric lymph nodes were performed on the 5th, 10th, and 15th day. Mucosal growth was higher in group C than B. Colony forming units (CFU) from cecal contents increased more in group B than in C. BTs in A, B, and C were 7/15, 8/15, and 2/15, respectively. Total CFUs in blood and tissues were 5.8X10(4)/g, 5.5X10(6)/g, and 1.8X10(4)/g, respectively. As for BT, the most frequent organism was Klebsiella in A (79.3%), but E. coli in B and C (94.2% and 55.6%). GLN seems to suppress luminal microbes, and reduces BT in short bowel due to enforced barrier function and proliferation of the mucosa.

Is Definitive Surgery Necessary for Fistula-in-ano in Infant

To clarify the necessity of surgery for fistula-in-ano (FIA) in infant, a retrospective analysis of 82 cases FIA in infant were performed for 11 years period from 1987 to 1998. Group A included 44 cases in the period of surgery oriented treatment to 1992, and group B contained 38, period of feeding control oriented management (FC) after 1993. FC, that was indicated in case with loose stool and eczematoid perianal skin (LSES), composed of quit breast feeding, change of cow milk or complete weaning. Surgical decision was made after improvement of stool condition. Fistulectomy was performed in 29 cases (65.9 %) of group A. However, in group B, only 15 cases (39.5 %) required surgery (p=0.0036). Thirty-four cases in B had the history of LSES, and FC was applied in 25, and was effective in 24. Among 24 cases, 21 showed complete healing with FC, 3 had surgery because of the persistent FIA, and 1 got operation due to no improvement of stool condition. In conclusion, FC has to be applied to FIA in infant before surgery, particularly in cases with history of LSES. As one of the etiologic factors for FIA, LSES could be considered to this particular age group.

Two Cases of Combined Transplantation of Liver and Kidney from Two Living Donors / 대한이식학회지

Combined liver-kidney transplantation has gained increasing popularity and applied for the patient with end-stage liver and kidney disease. There are some controversies about the sequence of transplantation. In general, the liver allograft is temporary placed before the kidney allograft. This method may provide some immunologic advantages that liver allograft may protect concomitantly transplantated kidney from rejection. In our opinion, kidney-liver sequence may provide several benefits in hemodynamic stability, safer monitoring and planned fluid replacement by urine flow assessment. Combined liver-kidney transplantation requires only conventional immunosuppressive drug dosage as in kidney transplantation alone. And combined liver-kidney transplantation can be performed with acceptable morbidity and mortality, and have exellent long term result. We present two cases of combined liver-kidney transplantation performed by kidney- liver sequence for complex end organ failure.

A Case of Duodenal Intramural Hematoma Associated with Henoch - Schonlein Purpura / 대한소화기내시경학회지

Henoch-Schonlein purpura is a condition of unknown origin probably related to an autoimmune phenomenon involving an IgA immune complex disorder. Henoch-Schonlein purpura is a rare cause of intramural hematoma of the duodenum. We herein report a case of intramural hematoma of the duodenum and duodenal obstruction associated with Henoch-Schonlein purpura in a 14-yearold boy. On admission, the patient presented with hematemesis due to duodenal ulcer bleeding. Three days later, he developed both forearm and calf purpurae, fever and severe bile juice vomiting. An endoscopy revealed a luminal obstructing erythematous mass with bulging nature at the third portion of the duodenum. Abdominal CT scan and hypotonic duodenography showed intramural hematoma in the third portion of the duodenum and luminal obstruction. Hematoma removal was performed for the correction of intestinal obstruction. Increased awareness of the gastrointestinal manifestations of Henoch-Schonlein purpura should aid in the recognition of this disorder.

Hirschsprung's Disease: Etiology and Pathophysiology

Abnormal distribution of the enteric nerves such as adrenergic, cholinergic and peptidergic nerves may cause the functional obstruction in Hirschsprung's disease (HD). Although the sustained contraction of the aganglionic segment is the main pathophysiology of HD, the etiology and pathogenesis is not thoroughly understood. With the recent progress of molecular biology and genetics,a more detailed approach to the pathogenesis of the HD can be undertaken. In this review, the roles of the nitric oxide, nitric oxide synthase and interstitial cells of Cajal on smooth muscle relaxation, the effects of extracellular matrix, cell adhesion molecules, neurotrophic factors on the migration and maturation of the neural crest cells are described. In the section of genetic factors, familial occurrences, association of chromosomal abnormalities, RET gene, glial cell line-derived neurotrophic factor gene, endothelin-3 gene and endothelin-B receptor gene and their relationships to HD is briefly reviewed.