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Biomedical subjects

C T Lim

Publications and source records attributed to C T Lim.

At least 55 records · Page 3Linked to original sources

Meconium ileus--a rare cause of neonatal intestinal obstruction in Malaysia.

Meconium ileus, rare in Malaysia, accounts for 3.7% of all neonatal intestinal obstructions (excluding imperforate anus) seen in the University Hospital, Kuala Lumpur, from 1980-1990. This paper retrospectively reviews our clinical experience with 5 cases of meconium ileus seen over a 12-year period from 1980-1991 in the University Hospital, Kuala Lumpur. Three of the neonates were Malays, and two were Punjabis. Four of them were full-term and one preterm. The birth weights ranged from 1900 to 3700 g, with a mean of 2670 g. One of them also had a sibling with meconium ileus. Two of them were found to have foetal ascites and one had intestinal obstruction, antenatally by ultrasonography. The remaining two were symptomatic soon after birth. Extensive calcification was observed on plain abdominal radiographs in three babies and dilated bowels in the other two. All of them underwent laparotomy and uncomplicated meconium ileus was confirmed in two cases, meconium peritonitis in two and one meconium pseudocyst in addition to meconium peritonitis. There was one intraoperative death, and one long-term survivor who did not have cystic fibrosis. The remaining three did not have additional features suggestive of cystic fibrosis, and finally succumbed to respiratory infection. Sweat test was not done to confirm the diagnosis for logistic reasons. The management of such patients proved to be a challenge to clinicians because of the rarity of this condition.

Female↗

Anti-peptide antibodies against the human blood platelet thromboxane A2/prostaglandin H2 receptor. Production, purification and characterization.

Two anti-peptide antibodies have been raised against the human blood platelet thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor. Based on the published sequence of the placental TXA2/PGH2 receptor, two decapeptide segments were selected as potential antigens: one in the first extracellular loop corresponding to residue 89 through 98, and the other in the C-terminal region of the intracellular domain corresponding to residue 314 through 323. Rabbits were immunized with each peptide, and the antisera were subjected to a two-step purification procedure. The IgG fraction was purified using a DEAE Affi-Gel Blue column, and the peptide-specific IgG was further purified by affinity chromatography employing each peptide as the immobilized ligand. The combined purification factor for both procedures was approximately 60-fold. By ELISA, both antibodies displayed immunoreactivity toward their synthetic antigens, solubilized platelet membranes and affinity-purified TXA2/PGH2 receptor protein. Furthermore, Western blot analysis revealed that: (1) each antibody reacted with the purified platelet TXA2/PGH2 receptor protein (55 kDa); and (2) each antibody recognized a single band (55 kDa) in solubilized platelet membranes. These findings establish antibody specificity for the human platelet TXA2/PGH2 receptor protein. Functional analysis demonstrated that neither antibody interfered with ADP- or U46619-induced platelet aggregation of [3H]SQ29,548 binding to the solubilized receptor. These results suggest that the antibody epitopes are separate from the TXA2/PGH2 binding domain. In summary, two specific anti-peptide antibodies have been raised against the human platelet TXA2/PGH2 receptor. These antibodies should prove to be of value in the further investigation of the platelet TXA2/PGH2 receptor.

Amino Acid Sequence↗

The use of fine needle aspiration biopsy in patients with multiple lymphadenopathy before open biopsy.

When a clinician is faced with a patient who presents with lymphadenopathy and in whom the clinical examination and routine investigations are normal, excision biopsy is usually the next step of management to obtain a tissue diagnosis. In a patient who has multiple lymphadenopathy, deciding on which node to biopsy can be difficult because some of the enlarged nodes may not reflect the true disease process. When such a lymph node is biopsied, the actual diagnosis can be delayed or even missed. Fine needle aspiration biopsy has been shown to be an effective tool in the investigation of multiple lymphadenopathy. Many, if not all, of the enlarged lymph nodes can be sampled at one sitting. If this procedure fails to provide a definitive diagnosis, the clinician should then proceed on to an open biopsy. Two cases of multiple lymphadenopathy in which open biopsies failed to reveal the true nature of the disease but subsequent fine needle aspiration biopsies did are presented and discussed.

Adult↗

PgH2 analogs as potential antiplatelet derivatives.

Previous observations implicating PgH2 as a direct activator of platelets suggested that derivatives of U46619, a well-characterized TxA2 receptor agonist having structural homology with PgH2, might possess antiplatelet activity. The present work describes the synthesis of [1S-(1 alpha,2 beta,3 alpha,4 alpha)]-3-[(tetrahydropyranyloxy)methyl]- 2-[2-[(triphenylmethyl)oxy]ethyl]-5-oxabicyclo[2.2.1]heptane (14) a potentially useful intermediate for the synthesis of various epoxymethano derivatives. The latter was converted to [1S-(1 alpha,2 beta (Z),3 alpha,4 alpha)]-7-[3-[[2- [(phenylamino)carbonyl]-hydrazino]methyl]-5-oxabicylo[2.2.1]hept-2 - yl]-5-heptenoic acid (23), an epoxymethano derivative of PgH2 containing a hydrazide lower side chain as previously used in the TxA2 antagonist, SQ 29,548. The intermediate 14 was also converted to [1S-(1 alpha,2 beta (Z),3 alpha,4 alpha)]-7- [3-[(hexylamino)methyl]-5-oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid (25) which contained a simple aza side chain as used in earlier antagonists. Derivatives 23 and 25 appeared to be specific antagonists of the human platelet TxA2 receptor as evidenced by their inhibition of U46619 (1.5 microM) induced aggregation of human platelet rich plasma (IC50 = 22 and 7 microM, respectively), while having little effect on ADP (2 microM) induced aggregation at much higher concentrations. In addition, one of these derivatives, the bicycloamine 25, was shown to compete for [3H]U46619 binding to washed human platelets with an IC50 value of 25 microM, supporting the notion that these derivatives were acting at the thromboxane receptor. However, the potency of these derivatives was less than for previously reported TxA2 antagonists, suggesting that simple linear combinations of functionality from molecules active at the human platelet thromboxane receptor will be of limited predictive value.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

Purification of the human blood platelet thromboxane A2/prostaglandin H2 receptor protein.

The human platelet thromboxane A2/prostaglandin H2 receptor has been purified 6100-fold to apparent homogeneity by a three-step chromatographic procedure with an overall yield of 6%. A 6-fold purification of the receptor was first achieved by chromatography of 3-[(3-cholamidopropyl)dimethyl-ammonio]-1-propanesulfonate (CHAPS)-solubilized membrane proteins from human platelets on a diethylaminoethyl (DEAE)-Sepharose column. The DEAE eluate fractions containing receptor activity were then applied to a newly developed affinity column using the cyclohexyl derivative of SQ30,741 (SQ31,491) as the immobilized ligand. Elution of the receptor from the affinity column with BM13.177 yielded a further purification of 1700-fold. An additional 4-fold receptor purification from the affinity column eluate was achieved by HPLC using GPC 500 and GPC 100 columns connected in tandem. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining of the HPLC eluate containing purified receptor revealed a single, distinct band with a molecular weight of 55,000. The receptor binding activity was detected with [3H]SQ29,548 using a newly developed binding assay which involved immobilization of the receptor on polyethyleneimine-treated glass fiber filters. The binding of [3H]SQ29,548 to the purified receptor was time dependent, saturable, reversible and highly specific. Unlabeled SQ29,548, BM13.505, and U46619 (but not thromboxane B2 or 6-keto prostaglandin F1 alpha) competed for [3H]SQ29,548 binding to the purified receptor in a concentration-dependent manner. Scatchard analysis of [3H]SQ29,548 binding to the purified receptor revealed the presence of a single class of high-affinity binding sites, with a Kd of 4 nM and a Bmax of 17 nmol/mg protein.

Blood Platelets↗

Cerebro-costo-mandibular syndrome.

Cerebro-costo-mandibular syndrome (CCM) is a very rare entity with oro-facial features closely resembling Pierre-Robin anomaly (1,2). We describe a patient with typical features: severe micrognathia, glossoptosis, central cleft soft palate and multiple posterior rib-gap defects seen on chest radiograph. Respiratory distress which was evident soon after birth was relieved by an oro-pharyngeal airway. He suffered from a cardiorespiratory arrest and succumbed, presumably secondary to aspiration of milk feeds, before a tracheostomy could be performed.

Humans↗

Bilateral ovarian cysts in a newborn: a case report.

Large ovarian cysts in the fetus are uncommon. Ultrasonography has helped in the detection of these cysts antenatally and in the newborn female infant. A case of bilateral ovarian cysts in a newborn is presented. The choice of management between conservative measures and surgical approaches remains controversial.

Female↗

Ingested foreign body in young children.

Locally, ingested foreign body is a problem commonly seen in the adult patients. Paediatric patients constituted about 6.5% of all cases of ingested foreign body. In adults and older children who are able to communicate, the management is usually straight forward. However, the diagnosis of ingested foreign body in a prelingual child may pose a problem as the child is unable to talk. A high index of suspicion is needed in the diagnosis of ingested foreign body. This article presents a case of undiagnosed ingested foreign body causing pharyngeal perforation with retropharyngeal abscess in a two year-old boy. The management of ingested foreign body in young children is discussed.

Abscess↗

Oculopharyngeal muscular dystrophy: a case report and a review of literature.

Most muscular dystrophies manifest as peripheral muscular weakness commencing at various age, however, oculopharyngeal muscular dystrophy (OPMD) is a rare hereditary disorder presenting in middle age with progressive dysphagia and bilateral blepharoptosis rather than peripheral muscular weakness. In the medical literature, OPMD has been well described in Canadians of French descent. So far, there is no publication of OPMD in the Malaysia-Singapore medical literature. This article documents this condition in a Chinese patient. A review of the literature is presented and the management of OPMD is discussed.

Aged↗

Sphenoid mucocele: detection and surgery by intranasal endoscopy.

Sphenoid sinus mucoceles are uncommon and difficult to diagnose clinically owing to the inaccessibility of the sphenoid sinus to clinical examination. A case of infected sphenoid mucocele in which the patient complained of chronic sore throat and in which routine intranasal endoscopy contributed significantly to the diagnosis is presented. The pathology of mucocele and endoscopic sinus surgery as the treatment for sphenoid sinus mucocele is discussed.

Adult↗

Depressed skull fracture in a newborn successfully managed conservatively: a case report.

A preterm baby was born to a multiparous mother by emergency caesarean section at 36 weeks of gestation. Apart from a depression on the right temporo-parietal region measuring 3 cm x 3 cm x 0.5 cm, no other abnormality was noted. A CT scan of the brain excluded the presence of intracranial haematoma and pressure effect on the brain. Spontaneous reduction of the fracture without any adverse neurological sequelae suggests that these fractures can be managed conservatively in some instances.

Cesarean Section↗

Early congenital syphilis: experience with 13 consecutive cases seen at the University Hospital, Kuala Lumpur.

While it is not difficult to recognise the classical clinical features of congenital syphilis in most cases, some of them may present with unusual manifestations which can defy early diagnosis. We report our experience with 13 cases of early congenital syphilis over a period of 10 years from 1980 to 1989. Twelve of the thirteen patients were less than 3 months at presentation. There were two infants born prematurely and six of the babies were born with a low birthweight (less than 2.5 kg). All but four patients survived following treatment. Skin lesions either in the form of typical vesiculobullous eruption over the palms and soles or a maculopapular skin rash over the body were the most common presentation and was seen in 10 patients. Splenomegaly with or without hepatomegaly was the most consistent physical sign. Radiological changes in the form of periostitis and/or metaphysitis were seen in all cases where an X-ray of the long bones was performed. An elevated serum immunoglobulin M, though non-specific for the disease, was found to be a useful screening test for recent infection.

Female↗

Malignant axillary lymphadenopathy--a problem for management.

Axillary lymph node enlargement can be the first and only manifestation of malignancy. Although lymphoma and metastasis from melanoma, breast and lung cancers are known causes, the primary tumour may remain undetected in some cases despite exhaustive investigations. Therefore, once the diagnosis of malignancy is confirmed by clinical examination followed by histology, further investigations should be limited to a search for treatable malignancies only. Extensive investigations with a hope of discovering the primary is useless and not cost effective. Close follow up may occasionally reveal new clinical signs when further investigations can be justified. This paper reports the clinical approach to diagnosis and management of such cases with examples of illustrative cases.

Adult↗

GIFT triplets and management problems--a case report.

Pregnancies conceived through assisted reproduction can present considerable management problems to the obstetric and paediatric staff. Multiple pregnancies are common. The complication of prematurity increases the morbidity and mortality rates of the neonates.

Adult↗

A 12-year experience of retinopathy of prematurity in infants less than or equal to 28 weeks gestation or less than or equal to 1000 g birthweight.

This study reported the prevalence and severity of retinopathy of prematurity (ROP) in less than or equal to 28 weeks gestation or less than or equal to 1000 g birthweight infants over a 12-year period. Among 328 survivors of less than or equal to 28 weeks gestation, 30% had ROP, 12% had severe ROP of Stage 3 or worse, 5% had at least one blind eye and 3% were bilaterally blind. Among 201 survivors of less than or equal to 1000 g birthweight, the above abnormalities were found in 40, 16, 6 and 4% respectively. In both cohorts there was a significant increase in the prevalence of ROP and severe ROP between the period 1977-80 and 1981-84, but the lesser increase observed between the periods 1981-84 and 1985-88 was not statistically significant. The rates of ROP-induced blindness were not significantly different between the three 4-year periods. An inverse relationship was noted between the prevalence of ROP and gestational age. The results suggest a resurgence of ROP in less than or equal to 28 weeks or less than or equal to 1000 g infants, the cause of which is uncertain. In view of this trend, continued surveillance of ROP is warranted.

Birth Weight↗