Diffusion-dependence of pulmonary gas mixing at 5.5 and 9.5 ATA

Gas-phase diffusivity is inversely proportional to pressure, so mixing of inspired gas in the lung can be expected to be poor in hyperbaric environments. Subjects performed multiple-breath wash-in of a mixture (4% each of SF6, Ar, Ne, and He; 21% O2, 63% N2) at 1.5, 5.5, and 9.5 ATA. At the higher pressures there were marked differences of concentrations between the indicator gases, measured by mass spectrometer at the mouth during a single expiration. Compared to heavier gases, light gases fell from dead space concentration to the "alveolar" level sooner, had a flatter plateau, and had a lower average expired concentration, indicating that more of the light gases were retained in the Functional Residual Capacity (FRC) after the breath. However, wash-in rates for the indicators were about the same; a rapid initial rate for He diminished so that it was about the same as the SF6 rate, because in later breaths a back pressure developed for He. The findings illustrate the basic principle that the amount of gas that diffuses from one location to another in a container depends not only on diffusivity, but also in an interdependent manner on concentration gradient, time for diffusion, and configuration of the container.     

Thyroid dysfunction after mantle irradiation of Hodgkin's disease patients

Thyroid dysfunction can develop in patients with Hodgkin's disease who are treated with mantle irradiation. During the period 1970-89, the records of 320 patients who received mantle irradiation and who had thyroid function tests (TFT) were retrospectively reviewed. The median age was 30 years (range, 7-69 years). The median mantle and thyroid dose was 36 Gy (range, 30-40 Gy) and 39.8 Gy (range, 32-65 Gy), respectively. Overall thyroid dysfunction was present in 39% of the patients. Clinical hypothyroidism was seen in 10% and biochemical hypothyroidism was noted in 25%. Hyperthyroidism was found in 4% of patients. Thyroid nodules had developed in six patients (2%), of which those in four patients were malignant. Age, sex, histological subtype, stage of disease, dose, lymphangiogram and treatment with chemotherapy were not significant factors in the development of thyroid dysfunction. The narrow dose range prevented adequate analysis of dose effect. The results indicate that the incidence of thyroid abnormalities is high enough to warrant regular TFT assessment with pre-irradiation levels and follow-up testing for life because the development of abnormalities can occur many years later. Thyroid examination should form part of the routine follow-up examination and any abnormality should be promptly investigated.     

台风伤害及其影响因素的现场流行病学研究

目的分析台风伤害的危险因素。方法采用现场流行病学调查方法,1:2配对的病例对照研究。对照组选伤害者邻居,按照同职业、同村庄、同性别和年龄±5岁配对。结果台风造成392人受伤住院治疗,50人死亡。伤害罹患率为27．3／10万,伤害致死率为11．3％,伤害死亡率3．1／10万。调查了209名受伤者和31名死亡者。发现伤害主要发生在台风来临前,其中台风来临前1～6小时之间有病例155例,占64．6％。209例伤害病例中,67．5％的病例曾得到过台风预警,但138名应答者中重视预警的只有47人,仅占34．0％。发现“台风来临时不在家中”[调整OR值(MH)=3．9 (95％CI:1．9～7．7)]、“台风来临前未得到预警”[调整OR值(MH)=3．3(95％CI:1．3～8．6)]和“虽得到预警但不重视”[调整OR值(MH)=17(95％CI:4．2～68)]是台风伤害的危险因素。结论外出、不重视预警是台风伤害的危险因素,应加强台风来临的预警宣传力度。     

The fludarabine,cytarabine, and granulocyte colony‐stimulating factor (FLAG) chemotherapy regimen is an alternative to anthracycline‐based therapy for the treatment of acute myeloid leukemia for patients with pre‐existing cardiac disease

We conducted a retrospective study assessing FLAG (fludarabine, cytarabine, and granulocyte colony‐stimulating factor) as first‐line treatment in 56 newly diagnosed acute myeloid leukemia patients considered ineligible for anthracycline‐based treatment due to advanced age, significant comorbidities, or pre‐existing cardiac disease. The median age was 69 (21–80); 46% received FLAG for pre‐existing cardiac disease and others due to age (32%), non‐cardiac comorbidities (20%), or previous anthracycline exposure (2%). The induction mortality was 16% and, among evaluable patients, 48% achieved a complete remission after the first induction course with an additional patient achieving a remission after a second course for a total complete remission rate of 50%. Four patients proceeded to an allogeneic stem cell transplant including two with pre‐existing cardiac disease. Among non‐transplanted patients, the relapse rate (RR) was 47%. When censored at time of stem cell transplant, the median relapse‐free survival was 14.7 months. The median overall survival was 9.3 months with 1‐ and 2‐yr survivals of 44% and 22%, respectively. There was no difference in clinical outcomes between patients treated with FLAG for cardiac reasons vs. other reasons. In conclusion, FLAG is a useful alternative to anthracycline‐based induction for Acute myeloid leukemia in those with significant comorbidities including pre‐existing cardiac disease.     

Transient Neonatal Zinc Deficiency Caused by a Novel Mutation in the SLC30A2 Gene

This is a case report of a 4‐month‐old full‐term, fully breastfed boy who presented with a persistent periorificial and groin rash associated with poor weight gain and irritability. His serum zinc level was low. The mother's breast milk zinc level was found to be low despite her serum zinc levels being normal, confirming the diagnosis of transient neonatal zinc deficiency. Mutational analysis revealed a novel mutation in the mother's SLC30A2 gene, which encodes a zinc transporter expressed in mammary gland epithelial cells.