Biomedical subjects
Publications and source records attributed to W H Lo.
A beta-thalassemia gene from a patient with beta+-thalassemia in South China was cloned and sequenced. A four nucleotide (TCTT) deletion in codons 41 and 42 was found. This is the most common beta-thalassemia gene in South China and the first mutant identified on China mainland.
In order to initiate a program of prenatal diagnosis for the prevention of beta-thalassemia in China, we have begun systematic studies of the beta-thalassemia mutations among the Chinese. DNA polymorphisms in the beta-globin gene cluster were examined in 46 beta-thalassemia chromosomes. Six different haplotypes were observed. One beta-thalassemia gene associated with a new haplotype was cloned and sequenced. The mutation was a single base substitution (A----G) at position -29 within the highly conserved proximal promoter element (the "TATA" box). This mutation was not observed previously in the Chinese. The beta-thalassemia genes were further screened with oligonucleotide probes specific for all known mutations in the Chinese. Five mutations were identified and accounted for 35 beta-thalassemia alleles.
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We have studied the spectrum of mutations producing beta-thalassemia (beta-thal) in South China and Southeast Asia in two groups of patients. In randomly selected patients with beta-thal major we characterized 78 beta-thal genes. In patients with beta-thal intermedia, 22 beta-thal genes were studied. The relevant mutation was characterized in all 78 genes of the first group, and 21 of 22 (96%) of mutant genes in the second group. Eight point mutations were found among the 100 genes studied. Of these eight alleles, four constituted 90% of the total. Prenatal diagnosis of beta-thalassemia in this region should be feasible by simplified techniques for direct detection of point mutations.
A Chinese beta +-thalassemia gene in a new haplotype was chosen for cloning and sequencing. The mutation identified was an A-G transition at position -29 in the TATA box of the beta-globin gene. This mutation has not been seen previously in Chinese but has been documented in American blacks on a different chromosomal background. This observation provides further evidence for independent origins of the same mutation in distinct ethnic groups.
To make possible prenatal diagnosis of beta-thalassemia in China and Southeast Asia by direct detection of mutant beta-globin genes, we have determined the spectrum of mutations producing the disorder in this region of the world. Seventy-eight beta-thalassemia genes from Chinese and Southeast Asians were randomly obtained, and the relevant mutation was characterized in 76 (98%) of them. Seven different point mutations were found among the 78 genes studied. Of these seven beta-thalassemia alleles, two constitute 62%, and two others account for 29% of the total. Since only four alleles make up 91% of the mutant genes, prenatal diagnosis of beta-thalassemia in China and Southeast Asia should be feasible by simplified techniques for direct detection of point mutations.
Coroners' statistics indicated there were 684 suicides for the whole of Hong Kong in 1981. This gave a crude suicide rate of 18.1 per 100,000 population aged 15 years and over and constituted 2.7% of all deaths reported in that year. Only a few data were recorded in all coroners' files but additional data were obtained from police records on 168 of these suicides. The age and sex distribution among the suicides as well as the effect of marital and employment status on suicide rates were found to be similar to western countries. Jumping from a height was the most common method of suicide (47.2%) followed by hanging (30.8%). Psychiatric illness and chronic physical disability were two most important precipitating causes of suicide (39.8% and 35.7% respectively). Twenty per cent had a history of previous attempts with one-third occurring within six months of their completed suicide. Over 40% had communicated their suicide intention to others, while 19% left a note. 'Psychiatric' cases as a group had special features: there were more in the younger age groups, more with records of previous suicide attempts and more chose readily available methods.
We report two cases of inherited balanced translocation with severe CNS abnormalities and a number of other physical findings. In both cases a multiple congenital anomalies/mental retardation (MCA/MR) syndrome was suspected. However, in one case, parturitional and neonatal complications probably resulted in brain damage; in the other, prenatal brain damage due to intoxication from a dead twin or porencephalic cysts due to vascular accidents remain unconfirmed hypotheses. It is concluded that no MCA/MR syndrome was present and that the inherited balanced translocation was a coincidental finding in these two brain-damaged, mentally retarded children.
One hundred and thirty-three Chinese schizophrenic patients first seen in 1965 were traced for a follow-up assessment in 1975. Eighty-two patients attended and were fully evaluated, 47 failed to attend and 4 were known to have died. The course and outcome were graded into four categories, and it was found that 65 per cent of the fully evaluated group had full and lasting remission or showed no or mild deterioration only, despite some relapses. Intra-group comparison showed that being female, a shorter duration of illness, an acute onset, symptom-groups other than disturbances of emotion and volition, and the presence of a supportive relative are factors which affect the prognosis favourably.
Indices were used to portray the rapidity and intensity of urbanization Hong Kong had undergone in the past 2-3 decades. Next the preliminary result of a psychiatric survey was quoted as an estimate of mental ill-health in Hong Kong. Data were obtained from the Mental Health Service to show the increasing demand for psychiatric care for the past 25 years. Attempts were made to analyze the basic composition of the new patients attending a psychiatric centre during this period. High density living associated with urbanization in Hong Kong was found to generate a high level of emotional strain, and psychiatric ill-health was as prevalent as that in New York. Neuroses were on the increase and psychiatrists were being consulted on a wider variety of problems. Provision of mental health care in future should take the changes in the composition of psychiatric populations into consideration.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
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Twenty-three cases of tuberculous osteomyelitis in children were reviewed. Age at diagnosis ranged from 10 months to 11 years; 17 patients were younger than 3 years. At clinical presentation, patients were generally afebrile with local swelling and painful limb disability. Delay in diagnosis was common, with an average of 4.3 months. Laboratory data showed mild increase in white cell counts and erythrocyte sedimentation rates. However, C-reactive protein levels were all within normal limits except one. Roentgenograms demonstrated osteolytic lesions over metaphyseal areas with surrounding soft-tissue swelling. All patients had received BCG vaccinations at infancy. None of the patients had pulmonary tuberculosis. No familial or environmental history could be attributed to these victims, nor was any immunodeficient disease noted. Bacille Calmette-Guérin (BCG) vaccination was suspected to be the cause of tuberculosis in these young children. All patients received surgical debridement and oral antituberculosis chemotherapy for 1 year. After an average follow-up period of 71.4 months, all children had complete bony healing and excellent clinical results.