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Biomedical subjects

H P Lin

Publications and source records attributed to H P Lin.

At least 73 records · Page 4Linked to original sources
PubMed1984

Testicular relapse in childhood acute lymphoblastic leukaemia in Malaysia, 1967-82.

From 1967-82, 9 children with testicular relapse (TR) of acute lymphoblastic leukaemia (ALL) were diagnosed out of 99 boys treated, an incidence of 9.1%. The median time from the onset of ALL until diagnosis was 28 months (range 3-41 months). All were asymptomatic; six were detected on routine examination while three were diagnosed only on biopsy. Routine biopsy prior to stopping chemotherapy is useful in detecting occult TR. Biopsies should be done on both the testes regardless of the clinical findings. The age, leucocyte count and hepatosplenomegaly at diagnosis of ALL were not found to be significant factors in influencing relapse. Eight children were in bone marrow remission at the time of TR, but three had preceding or concurrent meningeal leukaemia while in the other five the testis was the first and only site of relapse. Radiotherapy was effective in local disease control but failed to prevent bone marrow relapse in all except two patients despite continuation of chemotherapy. The median time from onset of TR until bone marrow relapse was 7 months (range 3-13 months) and the median time until death, was 11 months (range 6-18 months). The frequency of testicular relapse may be related to the intensity of either the initial induction therapy or the consolidation chemotherapy. Further studies are required to determine whether the incidence of testicular relapse will decline with more intensive early treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1984

Meiosis in Drosophila melanogaster. V. Univalent behavior in In(1)sc4Lsc8R/BsY males.

Univalent behavior during meiosis has been examined in Drosophila melanogaster males possessing the In(1)sc4Lsc8R X chromosome using light microscopy and serial section electron microscopy. Males from two stocks, displaying high (0.40) and low (0.14) frequencies of sex chromosome nondisjunction, have been investigated. The results demonstrate that (i) sex chromosomes are more intimately paired during prometaphase I in males from the low nondisjunction stock than in males from the high nondisjunction stock, and (ii) the univalents are distributed to the poles in an unbiased manner during meiosis rather than by directed segregation of both univalents to the same pole as previously determined for other In(1)sc4Lsc8R/Y males.

Animals↗
PubMed1983

Treatment of childhood acute lymphoblastic leukemia in Malaysia, 1976-1982.

One hundred four children with acute lymphoblastic leukaemia were diagnosed at the University Hospital, Kuala Lumpur, Malaysia, between 1976 and 1982; 87 were evaluable with respect to treatment. They were divided into good prognosis (GP) and bad prognosis (BP) groups based on their initial total white cell count, their treatment differing only during the maintenance phase. Remission was achieved in 82 patients (94%) of whom ten (12%) subsequently died in remission from infection. Twenty-eight (34%) relapsed while on treatment and three while off therapy. Eleven patients ceased treatment after 3 yr of continuous complete remission (CCR). Three of these later relapsed, two within the first year. Survival in CCR was significantly better in the GP group up to 30 months, after which the difference diminished. There was no difference in survival between boys and girls. The overall disease-free survival at 3 yr and 5 yr was 40% and 25%, respectively, with a median follow-up period of 20 months (range 4-69 months). The reasons for the relatively low survival rates as compared with those in developed countries are discussed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1982

Meiosis in Drosophila melanogaster. IV. The conjunctive mechanism of the XY bivalent.

Chromosome pairing during meiosis I in D. melanogaster males was investigated ultrastructurally by examining complete bivalents in electron micrographs of serial thin sections. The XY bivalent is characterized by the presence of the unique material located between the two half-bivalents at the site of synapsis. The material has a fibrillar appearance and is less electron dense than the surrounding chromatin. XY bivalents in XYY males and XY bivalents containing the X chromosome, In (1) sc4LSC8R, where the pairing sites of the X chromosome are inverted and partially deleted also possess this material. The material is not associated with autosomal bivalents and may represent a morphological manifestation of the hypothetical cohesive elements (collochores) which are thought to function in conjunction of the X and Y chromosomes (Cooper, 1964).

Animals↗
PubMed1982

Meiosis in Drosophila melanogaster. II. The prometaphase-I kinetochore microtubule bundle and kinetochore orientation in males.

Fourteen prometaphase kinetochore microtubule bundles have been examined in electron micrographs of serial sections. The majority (54%) of the microtubules extended from the polar region towards the kinetochore but do not end in the kinetochore proper. Rather, they stop short of the kinetochore (21%), graze the kinetochore (19%), or pass through the kinetochore (9%), displaying a free end distal to the pole. Other microtubules that make up the kinetochore bundle include: kinetochore-to-pole microtubules (24%), chromosome-to-pole microtubules (5%), pieces with two free ends (14%), and those microtubules with one end in the kinetochore and a free end distal to the kinetochore (9%). We conclude that the majority of the microtubules in the kinetochore bundle are most likely of polar origin rather than having been nucleated at the kinetochore. Prometaphase-I kinetochores can display any one of four patterns of microtubule connections with the poles, but the pattern of microtubule connections is not always correlated with kinetochore position. For instance, a kinetochore directly facing one pole may have microtubule connections with both poles while a kinetochore positioned 90 degrees to the spindle axis may have microtubules running towards one pole only.

Animals↗
PubMed1982

Meiosis in Drosophila melanogaster, III. The effect of orientation disruptor (ord) on gonial mitotic and the meiotic divisions in males.

Orientation disruptor (ord), a meiotic mutant that is recombination defective in females and disjunction defective in males and females, has been analyzed using serial section electron and light microscopy. From analysis of primary spermatocytes we have confirmed that ord males are defective in some aspect of the mechanism(s) that holds sister chromatids together during meiosis. In addition, we have determined that ord causes high frequencies of nondisjunction during spermatogonial mitotic divisions, as well as during the meiotic divisions. Mitotic nondisjunction involves the large autosomes more frequently than the sex chromosomes or chromosome 4 and results in high frequencies of primary spermatocytes that are either monosomic or trisomic for chromosome 2 or 3. Abnormalities in spermatocyte cyst formation are also observed in males homozygous for ord. These abnormalities include loss of regulation of meiotic synchrony and the number of gonial cell divisions.

Animals↗
PubMed1981

Meiosis in Drosophila melanogaster. I. Chromosome identification and kinetochore microtubule numbers during the first and second meiotic divisions in males.

Individual bivalents or chromosomes have been identified in Drosophila melanogaster spermatocytes at metaphase I, anaphase I, metaphase II and anaphase II in electron micrographs of serial sections. Identification was based on a combination of chromosome volume analysis, bivalent topology, and kinetochore position. - Kinetochore microtubule numbers have been obtained for the identified chromosomes at all four meiotic stages. Average numbers in D. melanogaster are relatively low compared to reported numbers of other higher eukaryotes. There is no differences in kinetochore microtubule numbers within a stage despite a large (approximately tenfold) difference in chromosome volume between the largest and the smallest chromosome. A comparison between the two meiotic metaphases (metaphase I and metaphase II) reveals that metaphase I kinetochores possess twice as many microtubules as metaphase II kinetochores. - Other microtubules in addition to those that end on or penetrate the kinetochore are found in the vicinity of the kinetochore. These microtubules penetrate the chromosome rather than the kinetochore proper and are more numerous at metaphase I than at the other division stages.

Animals↗
PubMed1981

Acute septicaemic melioidosis: a report of seven cases.

A report is presented of seven patients with acute septicaemic melioidosis seen at the University Hospital, Kuala Lumpur, Malaysia, during 1976-1979. All had associated disorders which rendered them more susceptible to infection. As prognosis depends on early diagnosis it is important that this disease be considered in the differential diagnosis of a septicaemic illness in such patients from endemic areas. The treatment of choice is a combination of tetracyclines and chloramphenicol, initially used in massive doses, and continued for at least six month to prevent relapses.

Adult↗
PubMed1980

Congenital leukemoid reaction followed by fatal leukemia. A case with Down's syndrome.

A serial clinical, hematologic, and cytogenetic study was done on a baby with Down's syndrome in whom a myeloid leukemoid reaction developed at birth that spontaneously regressed within a month only to relapse two years later to an acute undifferentiated stem cell leukemia. He died 1 1/2 months after onset. The unresolved controversy of the diagnosis of the congenital leukemia-like state is discussed. The importance of following up such patients with apparent remission of their congenital leukemia-like disorder is emphasized.

Down Syndrome↗
PubMed1980

Hypopyon--an early sign of leukaemic relapse.

A 5-year-old girl with ALL developed leukaemic hypopyon after 33 months of treatment. Bone marrow and CNS relapse developed 3 months later, which was successfully treated. Local radiotherapy did not prevent an ocular relapse 2 months later, and a second course of irradiation was successfully given. She developed a second bone marrow relapse and died about 9 months after hypopyon was first identified. It is postulated that hypopyon may be an early sign of leukaemic relapse.

Anterior Chamber↗