A huge 6.2 kilogram uterine myoma coinciding with omental leiomyosarcoma: case report

Surgery for massive abdominal tumors is both interesting and challenging. We present a case involving a multiple uterine myoma weighing 6.2 Kg which coincided with omental leiomyosarcoma. To our knowledge, this is the first report of this type of condition in the English literature. A 44-year-old nulliparous woman had suffered from abdominal pain for a long time. A huge abdominal mass was palpated on physical examination. Computed tomography scanning revealed a huge pelvic-abdominal mass with the possibility of small bowel loops invaded by the mass. A 6-cm omental mass was incidentally found during the subsequent hysterectomy procedure. Perforation of the urinary bladder occurred during the dissection of adhesion. Resection of the omental mass, wide wedge resection of the invaded small bowel, primary repair of the bladder, and hysterectomy were performed. The final pathologic diagnosis was uterine leiomyomata with omental leiomyosarcoma. The patient returned home on postoperative day 14 and was well at the 18-month follow-up examination. The challenge of these tumors lies in their proper diagnosis and surgical management. More case reports and follow-up studies are needed to confirm the efficacy of their management.

Kimura's disease in a teenage male: report of one case

A 14-year-old boy gradually developed several subcutaneous masses over bilateral peri-auricular regions, neck, and both upper arms near the elbows over the past 2 years. The recent development of eyelid puffiness elicited his seeking medical attention. Hypereosinophilic syndrome was first considered due to the markedly elevated blood eosinophil count without other evidence of allergy or parasite infestation, but the absence of organ involvement made this diagnosis questionable. The histopathological investigation of the subcutaneous mass in the upper arm showed lymph node-like tissue with markedly reactive follicular hyperplasia and eosinophilic abscesses associated with granulomatous inflammation, thus leading to the final diagnosis of Kimura's disease. Oral prednisolone was prescribed successfully. This illness occurs mainly in young oriental males. We report this case to introduce it to pediatric clinicians as an important differential diagnostic entity in eosinophilia-associated diseases and reactive lymphadenopathy.

Endoscopic management of injured bowel using the automatic stapler

Bowel injury is a rare but potentially fatal complication of laparoscopy if it is unrecognized at the time of the procedure. Once a bowel injury is identified, it must be repaired by either laparoscopy or laparotomy. The Endo GIA 30 stapler is effective for achieving large-vessel hemostasis and facilitating laparoscopic procedures, and is reported safe for laparoscopic hysterectomy. It was used successfully in two women to repair extensive bowel injuries.

Ribotyping of Vibrio parahaemolyticus isolates obtained from food poisoning outbreaks in Taiwan

Vibrio parahaemolyticus is a prevalent food-borne pathogen in Taiwan, Japan and other Asian countries. This work presents a novel ribotyping method for the molecular epidemiological examination of this pathogen. Genomic DNA was fragmented by HindIII digestion and hybridized with cDNA probe for Escherichia coli 16S and 23S RNA genes. A total of 121 isolates obtained from outbreaks during 1992 and 1994 in Taiwan were characterized by this ribotyping method. Four to seventeen restricted fragments were visualized in these isolates. After hierarchical cluster analysis, these isolates were grouped into thirty different ribotypes. In addition, A3, A7, E3 and F1 were the major ribotypes, consisting of 22.3, 13.2, 9.1, and 8.3% of the isolates, respectively. A, E, F, G and B were the major groups, consisting of 46.2, 14.0, 9.1, 6.7, and 6.7% of the isolates, respectively. The discriminatory ability of this ribotyping method, as determined by Simpson's index of diversity, was 0.93, which closely resembled that of a previously reported pulsed-field gel electrophoresis method.

Developmental neuroplasticity: roles in early life seizures and chronic epilepsy

Both clinical and experimental studies suggest that the immature nervous system is unusually susceptible to seizures during critical periods in postnatal life. A late onset of gamma-aminobutyric acid (GABA)-mediated synaptic inhibition could conceivably play a contributing role in this phenomenon. Numerous studies have shown that neural systems that use GABA in the neonatal brain are different than those of adulthood. GABA is an excitatory neurotransmitter that likely plays a neurotrophic role in neuronal differentiation. Other reports suggest that unique, possibly transient, GABAergic interneuron populations exist in the embryonic and neonatal nervous system. At these early times in development, the immature nervous system is remarkably resistant to seizure generation. However, as the hippocampus and neocortex enter the critical period of enhanced seizure susceptibility, inhibitory GABA systems mature rapidly. At this time, blockade of GABA type A (GABAA) receptors produce unusually severe seizure discharges. In hippocampus, concurrent exuberant outgrowth of recurrent excitatory axon collaterals and synapses appear to play a role in the generation of these seizures. As the hippocampus matures, these axons are morphologically remodeled and nearly 50% of branches within arbors are pruned. This pruning of axon branches corresponds in time with the decrease in seizure susceptibility that characterizes adulthood. Developmental remodeling of neuronal connectivity is a common feature of most areas of the central nervous system. Results from an audiogenic seizure model of early onset epilepsy suggest that prevention of axon arbor remodeling by transient sensory deprivation can lead to a permanent overinnervation of target nuclei and chronic seizure susceptibility. Early life seizures may have a similar effect. Recent results in one model have shown that repeated seizures induced by intrahippocampal injections of tetanus toxin during a critical period results in a chronic epilepsy. Future studies should attempt to determine if the synchronized discharging of early-life seizures prevents the remodeling of neuronal connectivity that normally takes place during postnatal development and results in an overinnervated and chronically hyperexcitable hippocampus.

Publication trends of vegetarian nutrition articles in biomedical literature, 1966-1995

We documented publication trends of vegetarian nutrition articles in biomedical literature between 1966 and 1995 using the National Institutes of Health MEDLINE bibliographic database. The publication rate of vegetarian articles increased steadily during the 3 decades, from an average of <10/y in the late 1960s to 76/y in the early 1990s. After adjusting for the total number of articles indexed in MEDLINE annually, we found that publication of vegetarian nutrition articles increased dramatically, by 4-fold, during the 1970s and reached an oscillating plateau during the 1980s. In the early 1990s, the proportion of vegetarian nutrition articles 8 articles per 1000 vegetarian nutrition articles and approximately 20 per 100000 articles indexed by MEDLINE. Non-nutrition journals have progressively published a larger share of all vegetarian articles in the biomedical literature during the period studied. The nature and study design of published vegetarian research has changed over the years as well. The proportion of original research and review articles increased whereas case series and letters to the editor decreased. Reports of epidemiologic studies of vegetarians with longitudinal designs have superseded cross-sectional designs in number and proportion. In 40% of all publications, preventive and therapeutic applications of vegetarian diets constituted the major themes of vegetarian articles in the decade of 1986-1995. However, 20 y earlier the main focus was on the nutritional adequacy of vegetarian diets. The progressive change in the themes of vegetarian nutrition publications is interpreted as a shift in the role of vegetarian diets in human nutrition.

Localized measurement of kinase activation in oocytes of Xenopus laevis

We have combined a rapid cytoplasmic sampling technique with capillary electrophoresis to measure the activation of protein kinase C (PKC) in a small region (approximately 60 microm) of a Xenopus oocyte. The phosphorylation of a fluorescent PKC substrate was measured following addition of a pharmacological or physiological stimulus to an oocyte. When substrates for cdc2 kinase (cdc2K), PKC, and protein kinase A (PKA) were comicroinjected into an oocyte, all three substrates could be identified on the electropherogram after cytoplasmic sampling. With this new method, it should be possible to measure simultaneously the activation of multiple different kinases in a single cell, enabling the quantitative dissection of signal transduction pathways.

Negative CLOtest pellet can be reused

BACKGROUND

The CLOtest is based on the production of ammonia from urea in the presence of urease. In theory, substrate that has not been consumed in a negative test can be reused.

METHODS

We collected negative CLOtest pellets after their first use and stored them at room temperature. Whenever a CLOtest was needed during endoscopy, two biopsy specimens were taken from the antrum. One specimen was tested with a new CLOtest and the other with one that had been used previously. Time to color change was observed in paired tests.

RESULTS

We used 216 previously used CLOtest pellets with biopsy specimens obtained from 317 patients. Of the paired tests, 204 matched positive and 108 tested negative. Only 5 paired tests had discrepant results. Three had positive results only with a new CLOtest, and 2 were positive only with the reused test. In positive paired tests, there was significant linear correlation in log-transformed color change time between reused and new tests (p < 0.001). Ninety-two percent of previously used pellets were reused fewer than three times before they yielded a positive color change; the interval to this occurrence ranged from 2 to 15 days. Compared with the new CLOtest, the sensitivity of the reused CLOtest was 98. 6% and the specificity was 98.2%.

CONCLUSIONS

A negative CLOtest kept at room temperature can be reused within a short period of time, in circumstances in which there are environmental and economic considerations to be taken into account.

Laparoscopic hemi-hysterectomy in treatment of a didelphic uterus with a hypoplastic cervix and obstructed hemivagina

Maldevelopment of the Müllerian duct system may result in various urogenital anomalies including didelphic uterus with a hypoplastic cervix and obstructed hemivagina. We report a patient with this anomaly who was treated by laparoscopic hemi-hysterectomy and hysteroscopic resection of hemivagina. A 17 year old patient who had complained of vaginal pus-like discharge on and off for 1 year was diagnosed by MRI to have a double uterus with obstructed right hemivagina and ipsilateral renal agenesis. After hysteroscopic identification of hypoplasia of the right uterine cervix, laparoscopic resection of the right uterus and right Fallopian tube and hysteroscopically assisted resection of the vaginal septa were performed successfully. From our experience, combined laparoscopy and hysteroscopy may be an efficacious alternative in the management and diagnosis of Müllerian anomalies.

Molecular typing of Vibrio parahaemolyticus isolates, obtained from patients involved in food poisoning outbreaks in Taiwan, by random amplified polymorphic DNA analysis

Vibrio parahaemolyticus is one of the most important food-borne pathogens in Taiwan, Japan, and other countries with long coastlines. This paper reports on the development of a new random amplified polymorphic DNA (RAPD) method for the molecular typing of this pathogen. The 10-mer primer 284 (5'-CAG GCG CAC A-3') was selected to generate polymorphic amplification profiles of the genomic DNA at an annealing temperature of 38 degrees C. A total of 308 clinical isolates of V. parahaemolyticus collected during food poisoning outbreaks in Taiwan, mostly occurring between 1993 and 1995, plus 11 environmental and clinical reference strains were analyzed by this RAPD method. A total of 41 polymorphic RAPD patterns were recognized, and these patterns were arbitrarily grouped into 16 types (A to P). Types A, B, C, D, and E were the major types, and subtypes C3, C5, E1, B1, D2, and A2 were the major patterns. The major types were phylogenetically more closely related to each other than to any of the minor types.

Vaginoscopy using hysteroscope for diagnosis of vaginal bleeding during childhood: case report

Vaginal bleeding is an uncommon and alarming symptom for children, and serious underlying causes should be excluded. Though vaginal bleeding during childhood was mostly associated with precocious puberty, the physician should keep in mind that local vaginal lesions such infectious vaginitis, vaginal trauma, and vaginal foreign bodies frequently present vaginal bleeding. A 10-year-old girl who denied any traumatic injuries or sexual abuse presented with profuse vaginal bleeding. She had normal development milestones and had no signs of thelarche or adrenarche. Her hymen was intact and the basal measurements of sex hormones including tyrotropic hormone and thyroxine were all within reference ranges. Finally, a laceration of the vaginal wall was found by vaginoscopy using a hysteroscope under general anesthesia and treated using gauze packing. We must emphasize the importance of vaginoscopy and examination under anesthesia in a child with vaginal bleeding to exclude local vaginal lesions. In addition, vaginoscopy using a hysteroscope makes the examination efficient and cost effective.

Laparoscopic management of an ectopic pregnancy in a previous Caesarean section scar

A case of laparoscopic management of an ectopic pregnancy in a previous Caesarean section scar is reported. A 30 year old woman was admitted to our hospital for profuse vaginal bleeding 2 weeks after an abortion had been performed. A urine pregnancy test was positive. Abdominal ultrasound revealed a well-encapsulated bulging mass over the lower anterior uterine wall measuring 7x5 cm. Hysteroscopy revealed retained gestational tissue in the lower corpus despite a normal uterine cavity. An incision was made over the most prominent area of the mass by operative laparoscopy. Dark reddish tissue suggestive of the products of conception was removed using grasping forceps. One-layer of continuous endoscopic sutures along the affected uterine wall was made with 1-0 Prolene. Laparoscopy enabled the successful treatment of an unruptured ectopic pregnancy in a previous Caesarean scar and made it possible to preserve the patient's reproductive capability.

Endoscopic ultrasonography in the differential diagnosis of giant gastric folds

Giant gastric folds (or large gastric folds) are found in both benign and malignant diseases, and differential diagnosis with either upper gastrointestinal X-ray or endoscopy is difficult. Sometimes, even endoscopic biopsy cannot establish a definitive diagnosis. Recently, endoscopic ultrasonography (EUS) has been used to study giant gastric folds. We performed EUS in 25 patients with giant gastric folds that had been detected with upper gastrointestinal X-ray or endoscopy. The definitive diagnoses were confirmed by histopathology, other examinations, or long-term follow-up. The final diagnoses of these 25 patients were gastric varices in eight, gastric lymphangiectasis in one, gastritis in four, gastric carcinoma (scirrhous type) in six, and gastric lymphomas in six. All patients with gastric varices had anechoic tortuous varicose veins in the submucosal layer. EUS images of gastric lymphangiectasis were similar to those of gastric varices. EUS revealed regular gastric wall thickening of the second (mucosa) and third (submucosa) layers in all cases of gastritis. The fourth (muscularis propria) layer was intact in the only case of mucosa-associated lymphoid tissue lymphoma (MALToma), but not in the other five cases of gastric lymphoma. The second and third layers of this MALToma were irregular in thickness and heterogenous in echogenicity, different from the characteristic EUS findings in gastritis. The fourth layer was markedly thickened only in malignant conditions. Differentiation of gastric cancer from lymphoma with EUS was difficult because of overlapping EUS findings. In conclusion, EUS is indicated for the differential diagnosis of giant gastric folds. In addition, it avoids the risk associated with biopsy of gastric varices.

Laparoscopically assisted full thickness skin graft for reconstruction in congenital agenesis of vagina and uterine cervix

In patients with agenesis of the vagina and cervix but with a functional endometrium, the traditional treatment is hysterectomy with construction of a neovagina. We report successful treatment by laparoscopically assisted full thickness skin graft for reconstruction in a patient with congenital agenesis of the vagina and uterine cervix concomitant with haematometra and ovarian endometrioma in a 12 year old girl. Postoperatively, the vaginal skin graft healed well, and menstruation first appeared 4 weeks later. In our opinion, a combined laparoscopic and vaginal procedure with full thickness skin graft is an efficacious alternative in managing such genital defects.

Recognition of functional pulmonary atresia by color Doppler echocardiography

Vigorous crying aids right ventricular ejection into the pulmonary artery. This phenomenon can differentiate functional pulmonary atresia from anatomic pulmonary atresia.

Comparison of invasive and noninvasive tests for detecting Helicobacter pylori infection in bleeding peptic ulcers

BACKGROUND

Eradication of Helicobacter pylori infection has been shown to prevent recurrent bleeding from peptic ulcers. However, the detection rate for H pylori infection seems to be underestimated in this group of patients and has been scarcely investigated.

METHODS

Eighty patients with bleeding peptic ulcer were studied for evidence of H pylori infection. Seventy-seven of these patients were enrolled as having H pylori infection after any one of the following 3 tests were positive: culture, histologic study, or any 2 of rapid urease test (CLO test), carbon 13-labeled urea breath test (UBT), and serologic examination. Fresh blood or blood-containing material in the gastric antrum was noted by panendoscopy in 22 patients (group A). In the remaining 55 cases there was no blood in the antrum (group B).

RESULTS

The sensitivities of the CLO test, bacterial culture, histologic study, 13C-labeled UBT, and immunoglobulin G serologic test were 45.5%, 36.4%, 77.2%, 95.4%, and 100% in group A, respectively, and 70.9%, 40.0%, 70.9%, 92.7%, and 96.4%, respectively, in group B. There was a statistically significant difference between the sensitivities found for CLO test and 13C-labeled UBT (p < 0.05). Of these 5 tests, only the sensitivity of the CLO test showed a statistically significant difference between groups A and B (p < 0.05). A delayed positive CLO test result was recorded in 13 patients (3 in group A, 10 in group B).

CONCLUSION

Noninvasive tests seemed to be more sensitive than invasive tests in detecting H pylori infection in patients with bleeding peptic ulcers. Blood in the antrum might reduce the sensitivity of the CLO test but have no effect on the other tests. The CLO test should be observed for more than 24 hours because of the possibility of a delayed positive result in some patients with bleeding peptic ulcers.

Quantification of the dissolved organic matter effect on the sorption of hydrophobic organic pollutant: application of an overall mechanistic sorption model

This study presents an overall sorption model to estimate the sorption equilibrium coefficients of hydrophobic organic pollutants for heterogeneous aquatic systems. This proposed model combines a series of sorption equilibrium relationships including the adsorption of dissolved organic matters on particulates, the binding between organic pollutants and dissolved organic matters, and the sorption of organic pollutants on particulates with or without the presence of dissolved organic matters. By using this model, variations among the sorption equilibrium coefficients with the concentrations of dissolved organic matters are obtained. Also discussed herein are case studies involving pollutants having a wide spectrum of K(ow)s, different types of dissolved organic matters, different pH values and ionic strengths. In most of the case studies, the sorption equilibrium coefficients initially increase with the-concentrations of dissolved organic matters and, then, decrease after reaching a maximum value. This study also addresses the relative errors of partition coefficients attributed to the negligence of the effect caused by the dissolved organic matter, the so-called third-phase effect.

Chinese characters: semantic and phonetic regularity norms for China, Singapore, and Taiwan

Cognitive models of language processing in English are founded on norms for word properties, but their universality is now being explored across different writing scripts and subject groups. Although Chinese characters are popular for this comparative work, their salient properties remain ill defined or poorly controlled. We describe how norms for semantic and phonetic regularity in Mandarin can be calibrated on a regional basis. The rating data that we present from China, Singapore, and Taiwan also illustrate why the diversity of both oral and written forms of Chinese should be considered in future empirical work.

Disclosure of the diagnosis of HIV/AIDS to children born of HIV-infected mothers

HIV disease in perinatally infected patients is now treated as a chronic illness of childhood. The effective use of highly active anti-retroviral therapy has contributed to the improvements in the prognosis of this illness. As this population matures, the issue of disclosure of diagnosis becomes more significant and part of their comprehensive medical care. The importance of disclosure relates directly to medication adherence, treatment compliance, sexual exploration, fears associated with premature death, and the child's developing autonomy. disclosure of HIV disease to an infected child poses complex issues, such as transmissibility, maternal guilt, more than one family member with the virus, and the potential for social stigma and isolation, among others. A change in perspectives is currently taking place regarding the process of disclosure, whereby it may be approached as a gradual discussion process over the life of the child. A method of gradual and partial disclosure to the child with consistent support by a multi-disciplinary team of providers has been a successful strategy for many children cared for at the New York Hospital-Cornell University Medical Center. Of 73 perinatally HIV-infected children who are 6 years of age or older, 41% have had complete disclosure and another 19% are partially disclosed. Continuous communication and negotiation among the members of the team, which includes the parents and caregivers, are vital to the gradual process leading to complete disclosure.

Survival and distribution pattern of childhood liver cancer in Taiwan

Studies of survival and distribution of liver cancer in children are scarce. In this study, using data from the cancer registry of Taiwan, from 1979 to 1992, we identified 377 young patients (0-15 years of age) suffering from liver cancer, coded 155 according to the International Classification of Diseases. Among these patients, 122 were histopathologically proven hepatocellular carcinoma (HCC) and 43 hepatoblastoma (HB). For survival analysis, we also searched for cases of liver cancer in 0-16 year old children in the Taiwan cancer registry for the period between 1988 and 1992. We found 109 cases with identification numbers and birth dates which allowed our cases to be linked with the death registry of the National Health Department of Taiwan enabling the calculation of 5-year survival rates using actuarial life tables. Between 1979 and 1992, for 122 HCC cases, there was a peak incidence at the age of 1 year, then a decline to a trough at the age of 4 years, after which the number of cases increased to the age of 15 years. After the age of 4 years boys outnumbered the girls by 2:1. 36 (84%) of 43 HB cases were under the age of 5 years and boys tended to outnumber girls by 2.9:1. Between 1988 and 1992, of the 109 patients, 49 were diagnosed histopathologically and 60 patients clinically. Their overall 5-year survival rate was 19%. The 5-year survival rate of the 28 HCC patients was 17%, whereas that of the 17 HB patients was 47%. In conclusion, our epidemiological findings indicate that the HCC distribution among children is different according to age and to some extent sex. The overall 5-year survival rate of children suffering from liver cancer was still unfavourable.

One-week low-dose triple therapy is effective in treating Helicobacter pylori-infected patients with bleeding peptic ulcers

Proton pump inhibitor (PPI)-based triple therapy, which combines a PPI and two antibiotics, is highly effective in eradicating Helicobacter pylori infection in peptic ulcer patients, even if given for only 1 week. However, the application of this regimen in patients with bleeding ulcers has not been adequately investigated. We studied the effectiveness of triple therapy in treating 122 patients with proven H. pylori infection, and bleeding stigmata on endoscopy; 97 had duodenal ulcer (DU), 15 had gastric ulcer (GU), and 10 had both types of ulcers. A regimen of omeprazole (20 mg), metronidazole (500 mg), and clarithromycin (250 mg) twice daily was administered for 1 week as soon as the patient could eat normally after bleeding, followed by omeprazole (20 mg) daily for 3 additional weeks. Follow-up endoscopy and 13C-urea breath tests (UBTs) were performed at least 4 weeks after triple therapy. A total of 104 patients completed the study, 83 with DU, 12 with GU, and nine with both. The overall ulcer healing rate was 97.1% and the eradication rate was 91.3%. Patients with and without H. pylori eradication did not differ significantly in terms of age, gender, UBT titer, units of blood transfused, or interval between endoscopy and the beginning of triple therapy. We conclude that 1-week low-dose PPI-based triple therapy is effective in eradicating H. pylori infection in patients with bleeding peptic ulcers. When followed by 3 weeks of additional PPI treatment, a satisfactory ulcer healing rate can also be achieved.

Spine loss and other persistent alterations of hippocampal pyramidal cell dendrites in a model of early-onset epilepsy

To explore the anatomical substrates for network hyperexcitability in adult rats that become chronically epileptic after recurrent seizures in infancy, the dendritic and axonal arbors of biocytin-filled hippocampal pyramidal cells were reconstructed. On postnatal day 10, tetanus toxin was unilaterally injected into the hippocampus and produced brief but recurrent seizures for 1 week. Later, hippocampal slices taken from these rats exhibited synchronized network bursts in area CA3C. Both the apical and basilar dendritic arbors of CA3C pyramidal cells were markedly abnormal in these epileptic rats. There was a considerable reduction in the density of dendrite spines, although the extent of this loss could vary among dendritic segments. Spine density on terminal segments of the basilar and apical dendrites was reduced on average by 35 and 20%, respectively. In addition, the diameters of these same dendritic segments were markedly reduced. Dendritic spine loss has previously been suggested to indicate a partial deafferentation of epileptic neurons, but this interpretation is difficult to reconcile with the critical role recurrent excitatory synaptic transmission plays in the generation of synchronized network burst. In this study, axonal arbors of CA3C pyramidal cells exhibited normal branching patterns, branching complexity, and varicosity density. This suggests that if deafferentation occurs, synapses other than recurrent excitatory ones are lost. The morphological abnormalities reported here would be expected to significantly alter electrical signaling within dendrites that may contribute importantly to seizures and other behavioral sequelae of early-onset epilepsy.

Pregnancy in a previous cesarean section scar: case report

An ectopic pregnancy developing in a previous cesarean section scar is an extreme rarity among all ectopic pregnancies. Due to the difficulty of making an accurate diagnosis, this kind of ectopic pregnancy is the most dangerous and life-threatening type. A 30-year-old woman, who was gravida 4, para 3, was admitted to our emergency room with massive vaginal bleeding. She had undergone a cesarean section due to a breech birth 3 months prior to this admission. Ultrasound examination showed a pregnancy located in the low corpus uterus. The possibility of a spontaneous abortion in progress or a cervico-isthmic pregnancy were considered. Due to the massive vaginal bleeding and unstable vital signs of the patient, surgical intervention was decided upon to save the woman's life. We first performed dilatation and curettage. There was no gestational villi and severe vaginal bleeding was noted during this procedure. An emergent exploratory laparotomy was then performed, followed finally by a hysterectomy. Pathologic findings confirmed the diagnosis of a pregnancy in the previous cesarean section scar. Diagnosis, prevention, clinical evaluation and management of these conditions are discussed.