Regressive Effects of Various Chemopreventive Agents on Azoxymethane-induced Aberrant Crypt Foci in the Rat Colon

Regressive effects of four chemopreventive agents [5-hydroxy-4-(2-phenyl-( E )-ethenyl)-2(5 H fura-none (KYN-54), S-methyl metbanethiosulfonate (MMTS), chlorogenic acid (CA), and piroxicam] on azoxymethane (AOM)-induced aberrant crypt foci (ACF) in the colon of male F344 rats were examined by dietary exposure. At six weeks of age, 60 rats of groups 1 through 5 received subcutaneous injections of AOM (15 mg/kg body weight) once a week for three weeks. Twelve weeks after the first carcinogen injection, wben the occurrence of ACF was maximal, the rats in groups 2 through 5 were started on diet containing the test chemicals as follows: group 2, KYN-54 (0.02%); group 3, MMTS (0.01%); group 4, CA (0.025%); and group 5, piroxicam (0.0125%). Group 1 (20 rats) was kept on the basal diet alone, and group 6 (12 rate) served as an untreated control. Rats in each group were killed at 6, 12, 18, or 24 weeks after the start of the experiment, and the yield of ACF in the colon of each group at 18 or 24 weeks was compared with that at 12 weeks. The number of ACF per rat colon of each group at 18 or 24 weeks was smaller than that at 12 weeks. The reduction rates at 18 weeks were 7% in group 1 (AOM alone), 11% in group 2 (AOM+KYN-54), 10% in group 3 (AOM+MMTS), 51% in group 4 (AOM + CA) ( P 0.01), and 33% in group 5 (AOM+piroxicam) ( P <0.02), while at 24 weeks they were 12%, 26%, 51% ( P <0.002), 43% ( P <0.05), and 70% ( P <0.001), respectively. These results indicate that chemopreventive agents for large bowel carcinogenesis, i.e., KYN-54, MMTS, CA, and piroxicam, are not only able to prevent the development of ACF, but also can regress ACF, which are regarded as precursor lesions of colorectal cancer.     

视网膜血管瘤增殖一年龄相关性黄斑变性的特殊类型

本文总结了年龄相关性黄斑变性的特殊类型—视网膜血管瘤增殖(RAP)的临床和造影表现及分期。RAP是起源于黄斑旁视网膜深层毛细血管的、以伴发多灶小片视网膜内出血及盘变前期即有视网膜-脉络膜血管吻合(RCA)形成为特征的新生血管性AMD。     

Dysphagia Lusoria Caused by Aberrant Right Subclavian Artery, Kommerell’s Diverticulum, Legamentum Ring, Right Descending Aorta, and Absent Left Pulmonary Artery: A Report of a Unique Vascular Congenital Disease Undetected until Adulthood and a Review of the Literature

An active otherwise healthy and middle-aged woman presented with left supraclavicular pulsation, right upper extremity claudication, and mild dysphagia. Evaluation revealed an aberrant right subclavian artery, Kommerell’s diverticulum with aneurysmal degeneration, legamentum arteriosum completing vascular ring, and absent left pulmonary artery with multiple collateral supply to the left lung. She underwent successful surgical repair via right thoracotomy, including division of the vascular ring, resection of the diverticulum and aneurysm, and finally reimplantation of the right subclavian artery to the aortic arch. Her symptoms resolved completely, and she was able to resume normal activities.     

Aberrant right subclavian artery as a new cardiac sign in second- and third-trimester fetuses with Down syndrome

OBJECTIVE: The right subclavian artery arises normally as the first vessel from the brachiocephalic artery of the aortic arch. An aberrant right subclavian artery arises as a separate vessel from the aortic isthmus and crosses to the right, behind the trachea. This variant is present in <1% of the normal population; however, in subjects with Down syndrome, an incidence between 19% and 36% was reported. The purpose of this study was to assess the possibility of the detection of an aberrant right subclavian artery in fetuses with Down syndrome. STUDY DESIGN: Fourteen consecutive fetuses with prenatally detected Down syndrome were examined between 18 and 33 weeks of gestation. The presence of an aberrant right subclavian artery was determined by visualization of the transverse 3-vessel trachea view of the upper thorax with color Doppler ultrasonography. RESULTS: The right subclavian artery was visualized in 100% of fetuses (14/14) with Down syndrome. An aberrant right subclavian artery was identified in 35.7% of trisomy 21 fetuses (5/14). In 1 fetus, the aberrant right subclavian artery was the only abnormal ultrasound finding. In 3 fetuses, an aberrant right subclavian artery was associated with an intracardiac echogenic focus plus additional extracardiac markers. In the fourth fetus, an aberrant right subclavian artery was associated with an atrioventricular septal defect. All 9 fetuses with Down syndrome with a normal origin of the right subclavian artery had additional cardiac and/or extracardiac abnormalities. In 12 cases, pregnancy was terminated; 2 fetuses were live born. CONCLUSION: This preliminary study suggests that the in utero identification of an aberrant right subclavian artery may be a new ultrasound marker to be found in fetuses with Down syndrome. Further studies are required to assess the incidence of aberrant right subclavian artery in normal fetuses.     

Lethal post-tonsillectomy hemorrhage

Background: Post-tonsillectomy hemorrhage (PTH) seems to be a rare but unavoidable complication. Due to the frequency of performed tonsillectomies, it can be estimated that a certain amount may result in a lethal outcome. This study was undertaken to evaluate the clinical features of these rare cases. Material and methods: Retrospective case series of five patients with lethal post-tonsillectomy hemorrhage are reported after they had undergone tonsillectomy by four different surgeons. The relevant literature was reviewed. Results: The youngest patient was 42 months and the oldest almost 13 years old. All patients were male. Three patients had left the hospital against surgeon’s recommendation 5 days following tonsillectomy. Preceding episodes of bleeding prior to the lethal bleeding occurred in two patients. Lethal PTH occurred in four patients within 5–9 days, the latest bleeding 39 days after surgery. In the literature, lethal PTH was described for eight patients since 1958. The youngest patient was 4 years, the oldest 18 years old (mean: 8.6 years; median: 6.5 years). In three patients, lethal PTH occurred on the day of surgery and the latest bleeding 54 days after surgery. Conclusion: Due to the paucity of reports, little reliable information can be obtained from the literature. It remains unclear, whether or not this reflects the true incidence of this complication. The experience with the five reported cases suggests, that immediate surgical treatment may have avoided lethal outcome in most cases. Therefore, a close postoperative follow-up is advisable to detect any episode of bleeding as soon as possible which should be referred to a specialist. Certainly, the collected data do not suffice to establish general guidelines, indicating that further collection of cases is required to assess characteristics of lethal PTH.     

Flexor digitorum longus accessorius in the club foot of an infant with Nager syndrome

The case of a male infant is reported who had club foot on the right side and pes adductus on the left side in combination with acrofacial dysostosis; he also demonstrated preaxial anomalies of the upper limbs indicative of Nager syndrome. In addition, an unusual aberrant muscle was discovered during surgical correction of the right club foot. Received: 22 March 1999     

Misleading appearances in pediatric uroradiology

Certain misleading appearances are peculiar to pediatric uroradiology. The most frequently encountered pitfalls are related to the bladder, to vesicoureteral reflux, and to the duplicated collecting system. The bi-chambered nature of the child's bladder, and the rapid settling of contrast material to the most dependent portion causes many pitfalls in diagnosis. When the child is prone, normal ureters may seem to be ectopic, and ureteroceles may become invisible. When the child is supine, the volume of urine in the bladder may be grossly under-estimated. Reflux can mimic function at urography. The dynamic nature of reflux leads to under-estimation of its presence and degree on the IVP and static cystogram. Reflux into an already dilated system can lead to over-estimation of its degree. Aberrant micturition with rapid refilling of the bladder can simulate incomplete emptying. The diagnosis of ectopic ureterocele is based on indirect evidence. Any condition that affects the urinary apparatus in the same way will have a similar appearance. A huge ureterocele may have a small ureter, and massive reflux into a lower pole ureter may make the diagnosis of duplication difficult. Ureterocele lookalikes, and effacement or intussusception of the ureterocele are cystographic pitfalls. Lower pole ureteropelvic junction obstruction and Wilms tumor in the lower portion of a kidney can have surprisingly similar appearances.     

迷走肝动脉的DSA研究及临床意义

目的 研究迷走肝动脉的解剖特征，探讨其临床意义。资料与方法 回顾分析1000例肝动脉DSA资料，将直接起自腹腔干及胃肠道供血动脉的变异肝动脉称之为迷走肝动脉（aberrant hepatic artery,AbHA)，并根据其在肝内的走行方向和分布范围不同，进一步将其分为迷走肝右动脉（aberrant right hepatic artery,AbRHA），迷走肝左动脉（aberrant left hepatic artery,AbLHA)，迷走肝中动脉（aberrant middle hepatic artery,AbMHA)，迷走肝固有动脉（aberrant proper hepatic artery,AbPHA)及迷走肝总动脉（aberrant common hepatic artery,AbCHA）等，分别统计其发生率，描述其起源、走行、分支、分布等解剖学特征。结果 1000例中，共发现210例存在AbHA，占21％，其中12例分别显示2支AbHA，共发现222支AbHA，其构成如下：AbRHA 102支（45.95%,102/222)，AbLHA88支（39.64%,88/222)，AbMHA 4支（1.80%,4/222),AbPHA 3支（1.35%,3/222)，AbCHA 25支（11.26%,25/222)。222支AbHA中，起于肠系膜上动脉114支（51.35%,114/222)，起于胃左动脉83支（37.39%，83／222），起于胃十二指肠动脉13支（5.86%,13/222)，起于腹腔干10支（4.50%,10/222)，起于胃右动脉2支（0.90%,2/222)。结论 AbHA是一种比较常见的肝动脉变异，熟悉这种血管变异对肝癌的动脉内化疗栓塞具有极其重要的临床意义。     

Pathological studies of aberrant peripheral nerve bundles of spinal cords

Summary Aberrant peripheral nerve fiber bundles, i.c., masses of peripheral nerve fibers without perineural sheath cells, are found in the perivascular spaces of some spinal cords. The 514 spinal cords examined for these structures were separated into two groups; 507 spinal cords without definite necrotic lesions (group 1) and 7 spinal cords (group 2) with old necrotic lesions in which there were numerous aberrant peripheral nerve bundles (APNB). In group 1, APNB were found in 41.0% of spinal cords. The incidence was the same for both sexes and increased in proportion to age. APNB were found predominantly in the middle and lower thoracic segments. On the transverse sections, APNB were located mainly in the central gray matter and in the anterior median fissure. Ultrastructural and histochemical studies showed that the myelin in APNB was peripheral in origin. Serial sections showed continuity between APNB and nerve roots. In group 2 cases, APNB were diffusely distributed throughout the old necrotic lesions and not restricted to perivascular areas.