Growth and nutritional status of the Evenki reindeer herders of Siberia

This study examines physical growth and nutritional status in a sample of 478 (247 males; 231 females) Evenki herders of Central Siberia. The Evenki display slow growth in stature and body weight, particularly during late childhood and adolescence. Adult males fall below the U.S. 5th percentiles for both stature and body weight. Adult females are below the 5th percentile for stature and approximate the 15th percentile for weight. Despite their diminutive size, the Evenki appear to have adequate energy reserves, as indicated by their skinfold measurements, which range between the U.S. 15th and 50th percentiles. Among adults, women are relatively heavier and fatter than men and tend to increase in weight and fatness with age. Poor growth in the Evenki does not appear to be directly attributable to limited food availability. Rather, it is hypothesized that elevated metabolic requirements, associated with adaptation to a high latitude ecosystem, are responsible for limiting the amount of energy that is allocated to growth. Relatively high levels of adiposity in adult females appear to be the product of changes in activity patterns and fertility levels that resulted after the collectivization of the Evenki. © 1994 Wiley-Liss, Inc.     

Analysis of DNA ligase IV mutations found in LIG4 syndrome patients: the impact of two linked polymorphisms

LIG4 syndrome patients have hypomorphic mutations in DNA ligase IV. Although four of the five identified patients display immunodeficiency and developmental delay, one patient was developmentally normal. The developmentally normal patient had the same homozygous mutation (R278H) in DNA ligase IV as one of the more severely affected patients, who additionally had two linked polymorphisms. Here, we examine the impact of the mutations and polymorphisms identified in the LIG4 syndrome patients. Examination of recombinant mutant proteins shows that the severity of the clinical features correlates with the level of residual ligase activity. The polymorphisms decrease the activity of DNA ligase IV by approximately 2-fold. When combined with the otherwise mild R278H mutation, the activity is reduced to a level similar to other LIG4 patients who display immunodeficiency and developmental delay. This demonstrates how coupling of a mutation and polymorphism can have a marked impact on protein function and provides an example where a polymorphism may have influenced clinical outcome. Analysis of additional mutational changes in LIG4 syndrome (R580X, R814X and G469E) have led to the identification of a nuclear localization signal in DNA ligase IV and sites impacting upon DNA ligase IV adenylation.     

用于婴儿母亲的新型手动吸乳器与微型电动吸乳器的功效比较研究

目的比较微型电动吸乳器(MEP)与设计操作更合科生理需求的新型手动吸乳器(MP)的功效.在产后8w,60例怀孕足月的哺乳母亲随意使用MP和MEP,每侧乳房10min.测量乳汁量、脂肪含量、乳汁流出方式.通过提问方式获得哺乳母亲对吸乳器的评价.当哺乳母亲以随意顺序使用吸乳器时,乳汁量与脂肪含量无显著差异.哺乳母亲对MP评价明显优于MEP,而且觉得MP更舒适,所以更乐于接受MP.保留MP比MEP的母亲明显增多.尽管MEP贵重,但MP显然更受哺乳母亲青睐.这种新型的、更接近生理操作的MP代表吸乳器技术的进步.     

Isoprenaline reverses the slow force responses to a length change in isolated rabbit papillary muscle

An alteration in the length of isolated cardiac muscle produces an immediate change in twitch force, then a slow further change in the same direction. We have found that the slow changes in force in rabbit papillary muscles are blocked or reversed by the ß-agonist, isoprenaline (1 M). The abolition of the slow responses by isoprenaline was not due to saturation of the myofibrils with Ca²⁺, as the blockade continued if the extracellular [Ca²⁺] was reduced in the presence of isoprenaline so that twitch force was <50% maximal. Ryanodine (1 M) did not block the slow responses, suggesting that the sarcoplasmic reticulum does not mediate the responses. These results suggest that changes of intracellular [cAMP] may mediate, or at least modulate, the slow force responses to a length change in cardiac muscle.     

Effect of Loxosceles gaucho venom on cell morphology and behaviour in vitro in the presence and absence of sphingomyelin.

This study was performed to investigate whether the toxic effects of Loxosceles gaucho venom on cells might be exerted via stimulators of TNF-alpha release generated by sphingomyelinase D--a major component of the venom. It was demonstrated that L. gaucho venom alone is unable to induce TNF-alpha release by J774A.1 cells, while in the presence of exogenous sphingomyelin it induces a high level of TNF-alpha release which is significantly increased by incubation with non-inactivated serum. Ceramide phosphate also induces TNF-alpha release in J774A.1 cells, but (unlike sphingomyelin/sphingomyelinase) the level of release is not influenced by the presence or otherwise of non-inactivated serum. L. gaucho venom does not induce proliferation of J774A.1 cells and even at high concentrations it does not affect their viability. J774A.1 cells, which prior to venom treatment were elongated and clumped, round up after venom treatment, but, revert to their original morphology after incubation with fresh medium. TNF-alpha resistant MRC-5 cells and TNF-alpha sensitive MCF-7 cells are susceptible to the toxic effect of both L. gaucho venom and ceramide phosphate. The results obtained in this study demonstrate that exogenous sphingomyelin can modulate, in vitro, the release of TNF-alpha induced by L. gaucho venom in mouse macrophages. In addition, the results also indicate that ceramide phosphate and L. gaucho venom are toxic to several different cell types, via a variety of mechanisms, some, but not all, of which may involve TNF-alpha as an intermediary.     

Otoacoustic emissions as a screening test for hearing impairment in children recovering from acute bacterial meningitis

OBJECTIVES: To study the efficacy of otoacoustic emissions (OAEs) as a screening test for hearing impairment in children with acute bacterial meningitis. Hearing tests were performed before discharge from the hospital in an attempt to improve coverage and avoid delays in the diagnosis of postmeningitic hearing loss. METHODS: Children with bacterial meningitis were recruited from 21 centers. In the 48 hours before discharge from the hospital, all patients underwent a thorough audiologic assessment consisting of transient evoked OAEs, auditory brainstem responses (ABRs), otoscopy, and tympanometry. Hearing loss was defined as ABR threshold >/=30 dB. The results of OAE screening were compared with the gold standard of ABR threshold. RESULTS: Of 124 children recruited, we were able to perform both OAEs and ABRs on 110 children. Seven (6.3%) of the 110 children had ABR threshold >/=30 dB; 2 had sensorineural hearing loss and 5 had conductive hearing loss. At follow-up, hearing loss persisted in both cases of sensorineural hearing loss and no new cases were identified. All 7 children with hearing loss failed the OAE screening test. Ninety-four children with normal hearing thresholds passed the test, and 9 failed. Thus, the screening test had a sensitivity of 1.00 (95% confidence interval, 0.59 to 1.00), a specificity of 0.91 (0.85 to 0.97), a positive predictive value of 0. 44 (0.20 to 0.70), and a negative predictive value of 1.00 (0.96 to 1.00). CONCLUSIONS: OAE screening in children recovering from meningitis was found to be feasible and effective. The test was highly sensitive and reasonably specific. Inpatient OAE screening should allow early diagnosis of postmeningitic hearing loss and prompt auditory rehabilitation.     

Positive association of farm or rural residence with acute myeloid leukemia incidence in a cohort of older women.

The etiology of acute myeloid leukemia (AML) is relatively unknown. Incidence rates are highest in the agricultural Midwest region compared with other regions of the United States. Many studies have examined the relationship between farming and leukemia, but most have mainly focused on men. We examined the potential association between farm or rural residence and AML in the Iowa Women's Health Study. In 1986, 37,693 women who were free of prior cancer completed a lifestyle and health questionnaire, which included a question on the place of residence. Women were subsequently followed until 2002 for cancer incidence; 79 women developed AML during the time period. Women who lived on a farm at baseline were more likely (relative risk, 1.91; 95% confidence interval, 1.19-3.05) to develop AML compared with women who did not live on a farm. Further, women who reported living on a farm or in a rural area were twice as likely (relative risk, 2.38; 95% confidence interval, 1.33-4.26) to develop AML compared with women who lived in a city with a population of >10,000 people. These results provide evidence that women who live on farms or rural areas are at an increased risk of AML.