Children on hunger strike: child abuse or legitimate protest?

The issue of children on hunger strike (voluntary total fasting) has not been reported before. The World Medical Association Declaration of Tokyo 1975 and the Declaration of Malta 1991 (revised 1992) provide clinicians with guidelines for the management of adult patients on hunger strike but do not mention children. We report the management of 14 Vietnamese children, aged 1 to 12 years, who took part in a hunger strike at a refugee detention centre in Hong Kong.     

Chronic major aphthous stomatitis: oral treatment with low-dose alpha-interferon

Two patients with chronic major aphthous stomatitis of at least 3 years duration were treated with single daily oral doses (1,200 IU) of interferon alfa-2 alpha (HuIFN alpha). Both patients responded with complete remission of aphthae within 6 weeks. One patient had no recurrence of the disease during a 6-month observation period. The second patient had a recurrent aphtha approximately 4 weeks after the initial lesion resolved; however, the recurrent lesion was less severe than the patient had historically experienced. Retreatment of the recurrent lesion with HuIFN alpha resulted in complete remission within 1 week, and there were no further recurrences during the 6-month observational period.     

BsiY I, a novel thermophilic restriction endonuclease that recognizes 5'' CCNNNNNNNGG 3'' and the discovery of a wrongly sequenced site in pACYC177.

A new type II restriction endonuclease designated BsiY I has been purified from a thermophilic soil Bacillus stearothermophilus strain. This enzyme recognizes and cleaves the highly degenerate sequence 5' CCNNNNN!NNGG 3'. During the identification of the recognition sequence of BsiY I, we discovered that there should be five G nucleotides instead of four at position 1227-1230 of the plasmid pACYC177.     

Neuraminidase-induced thrombocytopenia in mice: effects on thrombopoiesis

Previous studies to examine the effects of thrombocytopenia on thrombopoiesis have generally utilized immune-mediated platelet depletion. We have developed a nonimmune model to exclude the possibility that adverse immune-mediated effects have been misinterpreted as the physiological response to stimulation of thrombopoiesis. Thrombopoiesis was examined in mice after induction of thrombocytopenia with a single injection of the nonimmunologic agent neuraminidase (Ndase). Utilizing electron microscopy, we examined platelets and megakaryocytes (MK) obtained 8, 12, 24, 48, 72, 96, and 120 hr after administration of Ndase. Eight to 48 hr after induction of acute, severe thrombocytopenia (mean platelet count less than 50,000/microliters), the medians of the platelet sectional area distributions, as measured morphometrically, were significantly greater than the median platelet sectional area of pooled controls. The maximum median value for platelet sectional area was observed at 24 hr. The largest platelets in these samples contained more profiles of endoplasmic reticulum and Golgi cisternae, and a lower concentration of surface-connected canalicular system, as compared with normal platelets. By 72 hr post-injection of Ndase, virtually all platelets exhibited normal size and organelle complement. Mean platelet volumes, determined by electrical impedance analysis, paralleled the serial changes in platelet sectional areas. MK frequency and ploidy, measured by two-color fluorescence activated flow cytometry, were unchanged 12 and 24 hr following Ndase. At 48 hr, total MK frequency increased significantly (P less than 0.01) from 0.11% to 0.17%, and MK ploidy distribution shifted with a reduction in 16N MK (P less than 0.005) and an increase in 32N MK (P less than 0.01). MK ploidy was maximally altered from normal at 72 hr with increased 32N MK frequency (32.0%, P less than 0.001) and increased 64N MK frequency (2.4%, P less than 0.005). Morphologic and morphometric examination of MK at all time points did not reveal detectable changes from normal in cytoplasmic appearance or size, respectively. Therefore, we have demonstrated marked alterations of morphology and size of platelets, and of MK ploidy, using this nonimmunologic model. These studies further support our previous observations that megakaryocyte ploidy and platelet volume are independently regulated in response to depletion of the circulating platelet mass, and they show that these changes are not dependent upon the mechanism of thrombocytopenia.     

Larval development and metamorphic behaviour of the subtropical spionid polychaete Pseudopolydora vexillosa

Although newly described, Pseudopolydora vexillosa is one of the most conspicuous surface-feeding spioniform polychaetes in subtropical waters. This is the first report on larval growth and metamorphosis of P. vexillosa. Newly hatched (3-chaetigers stage) larvae of P. vexillosa reached metamorphic competence at 12-17 chaetigers stage when fed with Chaetoceros gracilis or Dunaliella tertiolecta at a concentration of ∼ 10⁵ cells ml^− 1 for 6 to 8 days at 32 psu and 27 °C. Larvae on these two diets achieved comparable levels, of approximately 70% metamorphosis. On the other hand, larvae fed with Isochrysis galbana or starved in 0.22 μm filtered seawater never reached competence during the 10 days of study. The effect of organic matter on larval substrate selection was examined using glass beads, manipulated sediments and natural sediments. A significantly higher percentage of larvae metamorphosed on glass beads that had been submerged in unfiltered natural seawater for 5 days as compared to the control; when manipulating the organic content of sediment as a substratum, significantly more larvae metamorphosed in 100% natural sediment, compared with 0%, 25%, 50%, and 75% natural sediment mixed with different portions of ashed sediment. Surprisingly, with natural undisturbed surface sediment sampled along a transect perpendicular to a sewage discharge site, these laboratory bioassays demonstrate that the larvae of P. vexillosa are capable of responding to sedimentary cues in complex ways to find a habitat suitable for metamorphosis and survival.