Search PubMed⌕ Search

Biomedical subjects

Alexander K C Leung

Publications and source records attributed to Alexander K C Leung.

At least 19 recordsLinked to original sources
PubMed2007

Hypospadias: an update.

Hypospadias is the most common congenital anomaly of the penis. The problem usually develops sporadically and without an obvious underlying cause. The ectopically positioned urethral meatus lies proximal to the normal site and on the ventral aspect of the penis, and in severe cases opens onto the scrotum or perineum. The foreskin on the ventral surface is deficient, while that on the dorsal surface is abundant, giving the appearance of a dorsal hood. Chordee is more common in severe cases. Cryptorchidism and inguinal hernia are the most common associated anomalies. The frequency of associated anomalies increases with the severity of hypospadias. For isolated anterior or middle hypospadias, laboratory studies are not usually necessary. Screening for urinary tract anomalies should be considered in patients with posterior hypospadias and in those with an anomaly of at least one additional organ system. The ideal age for surgical repair in a healthy child is between 6 and 12 months of age. Most cases can be repaired in a single operation and on an outpatient basis. Even patients with a less than perfect surgical result are usually able to enjoy a satisfactory sexual life.

Geography↗
PubMed2006

An approach to daytime wetting in children.

Daytime wetting is a common problem with various causes that can usually be identified through a careful history, thorough physical examination, and urinalysis. Conservative approaches to therapy have a successful outcome in most children. Invasive diagnostic imaging studies and pharmacologic or surgical intervention are necessary only for carefully selected children.

Arousal↗
PubMed2006

Catheterization of the bladder in infants and children.

Catheterization of the urinary bladder is a common procedure that can be emotionally and physically traumatic for the child and family. The purpose of this review is to familiarize readers with the procedure and techniques that will minimize the physical and emotional discomfort, and complications.

Child↗
PubMed2006

Rapid antigen detection testing in diagnosing group A beta-hemolytic streptococcal pharyngitis.

Group A beta-hemolytic streptococcus (GABHS) is the most common bacterial cause of acute pharyngitis. Clinical criteria alone are not reliable enough to diagnose GABHS pharyngitis. Microbiological-testing is required for correct diagnosis. Although a throat swab culture remains the gold standard for documenting the presence of GABHS, a significant disadvantage of the culture is the delayed time of 1-2 days to obtain results. Most rapid antigen detection tests can provide results in less than 15 min. Rapid identification and treatment of patients with GABHS pharyngitis can reduce the risk of the spread of disease, may shorten the duration of symptoms, decrease the incidence of suppurative complications, decrease the amount of time lost from school/work, decrease the inappropriate use of antibiotics, reduce patient/parent dissatisfaction and alleviate the need for costly follow-up visits. All rapid antigen detection tests involve extraction of the group-specific carbohydrate antigen from the GABHS cell wall and identification of the antigen by an immunological reaction. There are numerous rapid antigen detection testing methods, namely latex agglutination, enzyme immunoassay, optical immunoassay, chemiluminescent DNA probes and PCR methods. Most of the rapid antigen detection tests that are currently in use have an excellent specificity of greater than 95% and a sensitivity of greater than or equal to 90%. Owing to the high specificity of the rapid antigen detection tests, a positive rapid antigen detection test is accepted as adequate for the diagnosis of GABHS pharyngitis. Conversely, confirmation of a negative antigen detection test with a throat culture result is necessary, unless the physician has ascertained in his/her practice that the sensitivity of the rapid antigen test used is comparable with that of a throat culture.

Antigens, Bacterial↗
PubMed2006

Natal teeth: a review.

The incidence of natal teeth is approximately 1:2,000 to 1:3,000 live births. The most commonly affected teeth are the lower primary central incisors. Natal teeth usually occur in pairs. The eruption of more than two natal teeth is rare. The majority of natal teeth represent the early eruption of normal primary deciduous dentition. Less than 10% of natal teeth are supernumerary. Natal teeth might resemble normal primary dentition in size and shape; however, the teeth are often smaller, conical and yellowish, and have hypoplastic enamel and dentin with poor or absent root formation. Complications include discomfort during suckling, sublingual ulceration, laceration of the mother's breasts and aspiration of the teeth. A dental roentgenogram is indicated to differentiate the premature eruption of a primary tooth from a supernumerary tooth. Tooth extraction is indicated if the tooth is supernumerary or excessively mobile. If the tooth does not interfere with breastfeeding and is otherwise asymptomatic, no treatment is necessary.

Humans↗
PubMed2006

A malignant itch.

We report an unusual presentation of a previously healthy three-year-old Chinese girl with a four-week history of apparently unexplained generalized intense itch. She had no past history of atopy or xerosis. Despite the severe itch, she had only minimal scratch marks on her right gluteal region but no flexural involvement. The girl was treated as having scabies and eczema and with oral antihistamines by various dermatologists without much improvement. She subsequently presented to a regional hospital with right hip pain and fever. Radiological and histopathological investigations confirmed that she had a peripheral T-cell lymphoma. The itch pattern prior to and following chemotherapy, as documented by the DigiTrac wrist-held movement monitor, showed a dramatic reduction of her nocturnal itch. The pattern was also very different from that of atopic dermatitis in that the scratching was of much higher intensity but lower frequency. Intractable pruritus associated with a peripheral T-cell lymphoma has not been previously reported in the pediatric literature. This report serves to alert clinicians of the gold paradigm that in a patient with an unexplained generalized itch, lymphoma and other malignancies must be considered.

Child, Preschool↗
PubMed2006

Penile and oral angioedema associated with peanut ingestion.

Angioedema is characterized by transient, episodic, nonpruritic, nonpitting and well-defined edema that involves the subcutaneous or submucosal tissue, and most commonly develops in the head and neck region. Angioedema is caused by extravasation of plasma into the interstitial space of the affected tissue. We describe a six-year-old boy who developed oral and penile angioedema subsequent to the ingestion of peanuts.

Angioedema↗
PubMed2005

Persistent Mongolian spots in Chinese adults.

Four Chinese females aged 21-35 years with Mongolian spots are reported. Two patients had the spots on their arms while the other two had the spots on their shoulders. The persistence of Mongolian spots in Chinese adults has not been previously reported.

Adult↗
PubMed2005

Treatment of labial fusion with topical estrogen therapy.

Twenty girls with labial fusion that covered at least 50% of the vaginal opening were treated with a topical estrogen cream. The cream was precisely applied to the fused area twice a day until the adhesions were totally lysed. After separation of the adhesions, a petroleum ointment (Vaseline) was applied twice a day to the labia minora for at least 1 month. The introital area was carefully rinsed twice each day before application of either the estrogen cream or the petroleum ointment. The mean age of the studied population was 13.2 months (range, 2 to 38 months). The mean duration of estrogen treatment was 2.4 months (range, 1 to 3.5 months). All patients were successfully treated. Five patients developed vulval pigmentation, which lasted for a mean of 1.5 months. One patient developed breast enlargement, which lasted for 1 month. The mean duration of follow-up was 3.1 months, and there was no recurrence of labial fusion during the period of follow-up. We conclude that treatment of labial fusion with topical estrogen therapy is safe and effective.

Administration, Topical↗
PubMed2005

Primary and secondary nocturnal enuresis: similarities in presentation.

OBJECTIVE: To determine the differences or similarities in the clinical presentation between patients with primary and secondary nocturnal enuresis. METHODS: A total of 170 patients with nocturnal enuresis were assessed at a busy tertiary care pediatric voiding dysfunction clinic at the University of Oklahoma Health Sciences Center. Patients with primary nocturnal enuresis (PNE) were compared with patients with secondary nocturnal enuresis (SNE) for a variety of clinical features, including gender, age when first voiding on their own, age on presentation, infrequent voiding, frequent voiding, urgency, daytime wetting, nocturia, urinary tract infection, constipation, vesicoureteral reflux, attention-deficit/hyperactivity disorder, uroflow results, and ultrasound evidence of a postvoid residual. RESULTS: The only significant difference between the patients with PNE and those with SNE was in the prevalence of constipation. Constipation was significantly associated with PNE (74.59% vs 57.54%; odds ratio: 2.17; 95% confidence interval: 1.07-4.41). When adjusted for a history of constipation, the age at which a child began to void on his or her own became statistically significant. Patients with SNE started to void on their own at 2.13 years (SD: 0.61), an average of 0.22 years earlier than those with PNE, who started to void on their own at 2.35 years. CONCLUSIONS: PNE and SNE likely share a common pathogenesis. Symptoms of daytime voiding dysfunction are common in patients with PNE and SNE. Daytime voiding habits might influence how the central nervous system responds at night to a full or contracting bladder.

Age Factors↗
PubMed2005

Urinary tract infection due to Salmonella stanleyville in an otherwise healthy child.

A healthy four-year-old boy developed a febrile urinary tract infection (UTI) due to Salmonella stanleyville. The UTI developed following an episode of enteritis due to the same organism. Salmonella UTI is uncommon and is reported more often in patients with a predisposing factor, such as immune deficiency or a structural abnormality, in the urinary tract. Salmonella stanleyville has not been previously reported as a cause of UTI.

Child, Preschool↗
PubMed2005

Nonductal dependent coarctation: a 20-year study of morbidity and mortality comparing early-to-late surgical repair.

OBJECTIVE: The objective of this study was to evaluate the effect of the timing of surgical repair of nonductal dependent coarctation on the short-term outcome. METHODS: The medical records of 76 patients, diagnosed and treated for a nonductal dependent mild-to-moderate coarctation at a tertiary care institute over a 20-year period, were retrospectively reviewed with the age at repair compared against outcome measures. Multiple logistic regression was performed to assess the timing of repair, the presence of congestive heart failure or associated cardiac defects on the outcome measures. RESULTS: The mean age of surgery for the mild-to-moderate coarctation repair was 3.1 years (range: three days to 12 years). The most common cause for referral to a pediatric cardiologist was the clinical finding of a cardiac murmur. The timing of surgical repair was not found to be a predictor of morbidity or mortality. There was no significant difference in outcome measures defined as residual hypertension, residual coarctation gradient, persistent cardiomegaly, postoperative neurological sequelae, the requirement for a second surgery or the need for balloon dilatation for residual postoperative coarctation and the need for antihypertensive medications within five years postsurgery. CONCLUSION: The timing of surgical repair in the setting of nonductal dependent, mild-to-moderate coarctation of the aorta, does not adversely affect the short term (less than 20 years) outcome in children.

Age Factors↗