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Biomedical subjects

F M Lai

Publications and source records attributed to F M Lai.

At least 55 records · Page 3Linked to original sources
PubMed1996

Ultrastructural calcification of glomerular immune complexes.

We report a previously undescribed ultrastructural calcification of glomerular immune complex depositions in a patient with lupus nephritis. Such processes give rise to a distinctive ultrastructural calcified microspheriol in electron-dense immune deposits, and were associated with hypercalcemia and nephrocalcinosis. The cause of hypercalcemia in this patient was uncertain, but related to a granulomatous inflammation and abscess of the breast. Whereas ultrastructural microcalcification was associated with hypercalcemia, its distribution in the segmental glomerular lesions suggests that an inflammatory process was contributory. The clinical follow-up indicates that the microcalcifications of immune complexes have not affected the outcome of nephritis and renal function.

Adolescent↗
PubMed1996

alpha-(3,4-dimethyoxyphenyl)-3,4-dihydro-6,7-dimethoxy-alpha- [(4-methylphenyl)thio]-2(1H)-isoquinolineheptanenitrile (CL 329,753): a novel chemosensitizing agent for P-glycoprotein-mediated resistance with improved biological properties compared with verapamil and cyclosporine A.

Agents that inhibit P-glycoprotein may restore sensitivity to some antitumor drugs in cancer patients. Optimization of the specificity and potency of one class of chemosensitizing agents related to verapamil has led to the identification of alpha-(3,4-dimethyoxyphenyl)-3,4-dihydro-6, 7-dimethoxy-alpha-[(4-methylphenyl) thio]-2(1H)-isoquinolineheptanenitrile, designated CL 329,753. In vitro, 0.1 to 2.0 microM CL 329,753 restored sensitivity to drugs in the multidrug resistance (MDR) phenotype in cell lines that overexpress P-glycoprotein. CL 329,753 was greater than 10-fold more potent and efficacious than cyclosporine A or verapamil in vitro, particularly in cells that express high levels of P-glycoprotein. The enhanced activity of CL 329,753 may be related to its inability to be transported by P-glycoprotein, since low drug accumulation of cyclosporine or verapamil but not CL 329,753 was found in P-glycoprotein-containing cells, yet all three agents inhibited vinblastine binding to membranes containing P-glycoprotein and inhibited photoaffinity labeling of P-glycoprotein. In vivo, CL 329,753 resensitized drug-resistant tumors to vinblastine or doxorubicin in an ascitic or solid tumor model, respectively. No alteration in the plasma pharmacokinetic profile of doxorubicin by CL 329,753 has been found. Furthermore, the compound had 70-fold less calcium channel antagonistic activity compared with verapamil.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Hepatic mesenchymal hamartoma: a case report and radiological findings.

Primary tumours of the liver are uncommon in childhood. Of these, more than two-thirds are malignant. As such, benign hepatic tumours are often not considered in the differential diagnosis of a hepatic mass in childhood. We report a case of hepatic mesenchymal hamartoma, a rare benign tumour, in a 10-month-old infant. This tumour is characterised by an admixture of ductal structures within a copious loose connective tissue stroma. Only approximately 160 cases had been reported in the literature. Awareness of the ultrasound (U/S) and computed tomography (CT) features, although not diagnostic, is helpful in distinguishing it from the more common malignant tumours. A correct preoperative diagnosis is important as surgical excision is often curative.

Diagnosis, Differential↗
PubMed1996

A case-control study of parity, age at first full-term pregnancy, breast feeding and breast cancer in Taiwanese women.

A hospital-based case-control study was designed herein to investigate the relationship between parity, breast feeding and breast cancer in Taiwan. Reproductive histories of patients with breast cancer confirmed by either pathology or cytology were assessed by questionnaire and compared with age-matched healthy controls. One hundred and fourteen cases and 228 age-matched controls were recruited for this study. According to those results, women having had more than three full-term pregnancies, age at first full-term pregnancy younger than 30, and breast feeding for more than 3 years displayed significantly protective effects against breast cancer. Following adjustment for ethnicity and menopausal status, women with more than three full-term pregnancies and younger than 30 years old at first full-term pregnancy had a decreased risk of breast cancer. However, duration of breast feeding was not related to breast cancer, after adjustment for ethnicity and menopausal status. The effect of number of full-term pregnancies on the risk of breast cancer was found to be independent of the effect of age at first full-term pregnancy. Moreover, the effect of age at first full-term pregnancy and number of full-term pregnancies was also independent of the effect of breast feeding.

Abortion, Spontaneous↗
PubMed1995

Aggressive fibromatosis of the spermatic cord. A typical lesion in a "new" location.

The authors describe a 31-year-old man with a 7 cm aggressive fibromatosis (desmoid tumor) of the spermatic cord presenting as a swelling in the left inguinal area that was excised along with the testis and cord. The desmoid tumor is histologically typical, but such tumors arising primarily from the paratesticular structures have apparently not been previously reported and the diagnosis would not be questioned if it not for the unusual site. This tumor is histologically and immunohistochemically indistinguishable from abdominal wall desmoid tumor, with or without Gardner's syndrome. Desmoid tumors at this location should be distinguished from reactive processes, such as pseudosarcomatous myofibroblastic proliferation (so-called "proliferative funiculitis") and inflammatory fibrous pseudotumor, all of which exhibit fibroblastic/myofibroblastic differentiation. Paratesticular fibrosarcoma and leiomyosarcoma should also be differentiated from desmoid tumor that does not have the metastatic potential of sarcomas. Thirty-four months post-operatively, an 8 cm local recurrence in the remaining portion of the left vas deferens causing left hydroureter and hydronephrosis was detected.

Adult↗
PubMed1995

Acute tubular necrosis following endosulphan insecticide poisoning.

Endosulphan is a chlorinated hydrocarbon insecticide with potential toxicity for the respiratory and central nervous systems. Renal toxicity has been rarely reported. We describe a man who developed renal failure due to acute tubular necrosis following a suicidal attempt with endosulphan in the absence of significant hypotension or sepsis.

Aged↗
PubMed1995

Microscopic polyarteritis has a poor prognosis in Chinese.

OBJECTIVE: To analyze retrospectively the clinical course and outcome of 10 consecutive Chinese patients with microscopic polyarteritis (MPA) admitted to our hospital over a period of 3 years. METHODS: Ten patients with MPA who presented 1990-93 were studied. Their serum antineutrophil cytoplasmic autoantibody levels were assayed. RESULTS: The male to female ratio was 1:1 and the mean age was 61 years. Eight patients (80%) had renal impairment on presentation and 5 of them (50%) were dialysis dependent. Seven patients (70%), during their clinical course, had pulmonary hemorrhage. Six patients (60%) had hypoxic lung disease requiring ventilatory support. All 10 patients were pANCA positive; 8 patients were tested for antimyeloperoxidase antibody and were all positive. Seven patients were treated with immunosuppressants consisting of steroid and cyclophosphamide with additional plasma exchange. Nine patients died after a mean survival of 9 months (range 1-33); causes of death were respiratory failure (5), infection (2), uremia (one), and stroke (one). The ANCA level reflected the disease activity of the vasculitis. CONCLUSION: MPA in Chinese patients appeared to be a more severe disease with a poor prognosis. This may be related to the older age group, and the more frequent and severe pulmonary and renal manifestations of MPA in these patients.

Adult↗
PubMed1995

Metastatic cervical carcinoma presenting as psoas abscess and osteoblastic and lytic bony metastases.

A 60-year-old Chinese lady presented with a left flank mass and weight loss. Plain films showed a sclerotic L1 vertebral body, osteopenic L2 and L3 vertebral bodies and loss of left psoas outline. However initially unrevealed history of previous carcinoma of the cervix caused confusion as to the aetiology of a sclerotic vertebral body associated with an left flank collection. Psoas abscess with adjacent bony osteomyelitis was initially suspected. The left flank mass turned out to be an infected necrotic large metastatic lymph node compressing the lower pole of the left kidney. The sclerotic and osteopenic vertebral bodies represented an unusual presentation of bony cervical carcinoma metastases.

Bone Diseases, Metabolic↗
PubMed1995

Dermatofibrosarcoma protuberans in a renal transplant patient.

Dermatofibrosarcoma protuberans in an unusual soft tissue tumour with a propensity for local recurrence and rarely metastatic spread. Given its indolent course it may be mistaken for atypical scarring or a keloid growth. Early diagnosis and prompt wide local resection of this entity are required in order to prevent a local recurrence. We report a patient who developed locally invasive dermatofibrosarcoma protuberans 4 years after a successful renal transplantation. Although other forms of sarcoma have been reported as a complication of organ transplantation and immunosuppression, this pathology has, so far, not been reported in a transplant recipient.

Adult↗
PubMed1995

Reference charts of foetal biometry in Asians.

OBJECTIVES: To construct reference ranges for foetal biometry measurements of biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femur length (FL), humerus length (HL) and mandible length (ML) for the Asian population in Singapore. DESIGN: A prospective, cross-sectional study. SETTING: The obstetric ultrasound services and the labour ward of the department of Obstetrics and Gynaecology in Singapore General Hospital. SUBJECTS: The foetuses of 6,374 women whose delivery date was within 2 weeks of their estimated date of delivery (EDD) as calculated from the last menstrual period. METHOD: During the period August 1, 1989 and December 31, 1993, 17,005 obstetric ultrasound scans were retrieved from the computerised database. These ultrasound scans were cross-referenced with the delivery database and the earliest ultrasound scan of 6,374 women who delivered within 2 weeks of their EDD were retrieved for analysis. Different growth models were fitted using regression analysis to estimate the mean and standard deviations as functions of gestational age. Centiles were then derived after confirming a normal distribution of measurements at each gestation. RESULTS: A total of 6,131 measurements of the BPD, 6,117 measurements of the HC, 6,017 measurements of the AC, 6,078 measurements of the FL, 2,863 measurements of the HL and 2,029 measurements of the ML were obtained. Regression analysis using the linear-cubic formula was used to model the mean values; a separate linear regression analysis was used to model the standard deviations. CONCLUSION: These are the regressed reference charts from 6,374 Asian foetuses using parametric analysis of cross-sectional data. The authors encourage their use in Asian foetuses.

Anthropometry↗
PubMed1994

Increased mRNA encoding for transforming factor-beta in CD4+ cells from patients with IgA nephropathy.

IgA nephropathy (IgAN) is a mesangial proliferative glomerulonephritis characterized by predominant mesangial IgA deposits. Recently, transforming growth factor-beta (TGF-beta) is shown to exert widespread effects on extracellular matrix by enhancing its accumulation. In an experimental model of acute mesangial glomerulonephritis TGF-beta appeared to be involved in the process of glomerulosclerosis, and treatment with antagonists of TGF-beta prevented the development of glomerulosclerosis. We examined the TGF-beta mRNA expression by mitogen activated CD4+ T cells from 31 patients with IgAN, 25 healthy controls and 10 patients with minimal change nephropathy (MCN) or focal glomerulonephritis (FGN) who were comparable in age and sex. The cytokine gene was analyzed with reverse transcription followed by polymerase chain reaction and was semiquantitated by normalizing the differences occurring during reverse transcription and polymerase chain reaction using a housekeeping gene, beta-actin. CD4+ T cells from IgA nephritic patients expressed a higher level of TGF-beta mRNA than that of healthy controls or that of MCN/FGN [TGF-beta/actin ratio 1.11 (median), range 0.24 to 3.87 vs. 0.88, range 0.2 to 3.83, P = 0.0157 and 0.36 range 0.09 to 1.6, P = 0.006]. When the biopsies were classified into three grades according to the severity of glomerular and interstitial pathology, there were highly significant differences between the TGF-beta mRNA in CD4+ T cells from the three groups of IgA nephritic patients (grade 1, 0.52, range 0.24 to 0.79; grade 2, 1.2, range 0.5 to 3.33; grade 3, 2.17, range 1.45 to 3.87].(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Primary glomerulonephritis with detectable glomerular hepatitis B virus antigens.

The glomerular pathology and hepatitis B virus (HBV) antigens in renal biopsies were investigated in 100 consecutive patients with both primary glomerulonephritis and positive serology for hepatitis B surface antigen (HBsAg). Glomerular HBV antigens including HBsAg, hepatitis B core antigen (HBcAg), and hepatitis B e antigen (HBeAg) were examined in frozen tissue using both polyclonal and monoclonal antibodies. HBV serology and glomerular antigens were correlated. Using monoclonal antibodies, at least one of the three HBV antigens was detectable in glomeruli in 39% of the cases. These findings correspond mainly to detectable glomerular HBsAg and HBeAg in 22.3 and 28.4% of cases, respectively. A good correlation was found between glomerular and serum HBeAg but not observed for HBsAg. Serum HBcAg was not examined and not correlated with glomerular staining. When the diagnosis of HBV-related glomerulonephritis was based strictly on detectable glomerular antigens, three distinctive morphologies were identified: membranous nephropathy, mesangiocapillary glomerulonephritis, and mesangial proliferative glomerulonephritis with immunoglobulin A (IgA) deposits (IgA nephropathy). Each of these lesions may be seen in pure form or occasionally in overlapping form leading to double glomerulopathies. Glomerular HBeAg and HBsAg were associated with subepithelial and mesangial immune complexes, respectively. Rare overlap between membranous nephropathy and IgA nephropathy further emphasized the distinctive pathology of HBV-related glomerulonephritis and the independent etiological role of HBeAg and HBsAg. In other glomerulonephritis, which rarely demonstrated glomerular HBV antigens, the pathogenetic role of chronic HBV infection remains to be proven.

Adolescent↗
PubMed1994

Use of antineutrophil cytoplasmic autoantibodies in diagnosing vasculitis in a Chinese patient population.

Antineutrophil cytoplasmic autoantibodies (ANCA) have been used as markers of systemic vasculitides, including microscopic polyarteritis (MPA) and Wegener's granulomatosis. The diagnostic potential of ANCA assays together with antibodies against the neutrophil enzymes myeloperoxidase (MPO) and proteinase 3 for detecting a systemic vasculitis was tested in a Chinese patient population. 672 sera were received for ANCA assay, and ANCA detected by indirect immunofluorescence was positive in 73 sera from 42 patients. Of the 42 patients, 3 had cytoplasmic ANCA, while 39 had a perinuclear pattern. There was no patient with Wegener's granulomatosis. Two cytoplasmic ANCA positive patients suffered from ulcerative colitis. Another cytoplasmic ANCA positive patient was a carrier of human immunodeficiency virus. Of the 39 perinuclear ANCA positive patients, 10 had MPA. Eight of them were tested for anti-MPO antibody, and all were positive. Other immune disorders that were perinuclear ANCA positive included: 13 patients with systemic lupus erythematosus, 3 with mixed connective tissue disease, 1 with Goodpasture's syndrome, 2 with inflammatory bowel disease, and 2 patients with IgA nephropathy. Anti-MPO antibody was not specific for MPA, and 7 out of the 13 patients with systemic lupus erythematosus were anti-MPO antibody positive. Our study suggests that ANCA and anti-MPO antibody are not specific for MPA in a Chinese population. They would alert the clinician of the possibility of vasculitis, but a clinicopathological correlation is essential in making the diagnosis.

Adolescent↗
PubMed1994

Racial differences in fetal morphometry in Singapore.

A systematic collection of fetal morphometric measurements was started seven years ago in 1987 with the prospective entry of data into personal computer-based stations in the Department of Obstetrics and Gynaecology, Singapore General Hospital. A cross-sectional study was done, comparing 2392 Chinese fetuses with 2117 Malay fetuses and 459 Indian fetuses from 18 to 40 weeks. The mean values of the head circumference (HC), abdominal circumference (AC) and femur length (FL) of the 3 ethnic groups were analysed. There were no statistical significant differences in the head circumference and abdominal circumference of Chinese, Malay and Indian fetuses in Singapore. The Chinese and Malay fetal femur length appeared similar but were apparently shorter than the Indian femur length. Nomograms of head circumference, abdominal circumference and femur length were constructed for application to fetuses of all 3 ethnic groups.

Abdomen↗
PubMed1994

Pulmonary hemorrhage. A fatal manifestation in IgA nephropathy.

Two patients with asymptomatic IgA nephropathy (IgAN) and a third patient with chronic renal failure due to IgAN died following a recent onset of dyspnea, hemoptysis, and pulmonary infiltrates. In all cases, the cause of death was respiratory failure attributed to either bronchopneumonia or pulmonary edema. However, no infectious agent was identified. In all three patients, the diagnoses of IgAN and idiopathic pulmonary hemorrhage were established at postmortem examination. Acute alveolar hemorrhage was present in two patients. All three patients had heavy alveolar hemosiderin-laden macrophages, and capillaritis was recognized in two of them. The occurrence of fatal pulmonary hemorrhage in patients with IgAN is rare. Our findings suggested an immune complex-mediated pulmonary injury that was possibly related to the systemic nature of IgAN.

Adult↗
PubMed1993

Nodular fasciitis of the dermis.

We describe the second reported patient with nodular fasciitis involving the dermis. Our case was morphologically a typical example of nodular fasciitis, but was distinctive by its cutaneous location and recurrence. As in the first reported case, the unexpected dermal involvement caused diagnostic difficulty, despite a typical histology.

Child↗