Seasonality of sudden infant death syndrome (SIDS) is a well-established epidemiological finding. The purpose of the study was to determine whether this feature varied significantly with age at death. In total, 13 990 cases of SIDS in Scotland, England and Wales during 1982–1992 were studied by age group at death. Seasonality was established by fitting a sinusoidal curve and for each set of monthly data the peak position in the year and its magnitude were determined. Weighted regression revealed significant differences in peak position and amplitude of seasonal variation between those dying at ≤ 4 months and those aged ≥ 5 months at death. Those infants in the younger age group were more likely to die earlier in the winter months and had a smaller variation in seasonality. The peak (acrophase) months were January for ≤ 4 months and February for ≥ 5 months at death. Weighted regressions of peak position and amplitude on age at death had p-values of < 0.001 and < 0.01, respectively. A log linear model relating SIDS incidence to month of birth, month of death and age was able to explain some of these findings. The findings support the hypothesis that in SIDS there may be more than one infant cohort, each of which passes through a vulnerable developmental window at different ages. 相似文献
A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidosis. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of Tc PYP scanning as a screening test for soft-tissue amyloidosis is discussed. 相似文献
Background: The goal of this investigation was to characterize the effects of thiopental on cardiac output and regional blood flows in the rat. Blood flows influence thiopental pharmacokinetics. Acquisition of these data may ultimately permit evaluation of the contribution of thiopental-induced alterations in regional blood flows to the disposition and hypnotic effect of this drug.
Methods: Chronically instrumented unrestrained Wistar rats (n = 20) aged 3-4 months received either a dose of thiopental sufficient to induce a brief period of unconsciousness (20 mg *symbol* kg sup -1) or a larger dose achieving electroencephalographic burst suppression (45 mg *symbol* kg sup -1). Cardiac output and blood flows to 14 tissues were determined at 4 times in each rat for a period of 420 min using injections of radioactive microspheres (expressed as mean+/-SD). Mean arterial pressure, heart rate, and blood gas tensions were determined at all measurement times. Arterial plasma concentrations we sampled at postinfusion times.
Results: No important changes in systemic cardiovascular measurements were detected after the smaller dose of thiopental. One minute after the larger dose, cardiac output decreased from baseline (123+/-14 to 84+/-11 ml *symbol* min sup -1, P < 0.01), flow to muscle and fat decreased, and muscle and fat resistance increased. At 5 min, compared to baseline, no difference in cardiac output was detected (123+/-14 vs. 119+/-11 ml *symbol* min sup -1), intestinal flows increased, and intestinal resistances decreased. Cardiac output was again depressed at 30, 90, and 180 min. Brain blood flow decreased 25+/-19% (P < 0.01) from baseline for the duration of the study. 相似文献
A computed tomographic (CT) guided transgluteal approach through the greater sciatic foramen was used to drain pelvic abscesses and fluid collections in 21 patients. Ideal catheter placement should traverse the lower portion of the greater sciatic foramen at the level of the sacrospinous ligament. This avoids the vascular and neural elements that are located slightly cephalad at the level of the piriformis muscle. Percutaneous drainage through this approach was successful in avoiding surgery in 17 patients (81%). Pain was the most common complication and was generally associated with a more cephalad approach, transgressing the piriformis and the sacral plexus. CT-guided percutaneous drainage of pelvic abscesses through the greater sciatic foramen should be used when the more standard transperitoneal approach is not possible. 相似文献
Spinocerebellar ataxia 7 (SCA7) is caused by the expansion of an unstable
CAG repeat in the first exon of the SCA7 gene. We have analyzed the SCA7
mutation in 19 families and one isolated case of various geographical
origins, presenting with autosomal dominant cerebellar ataxia with
progressive macular dystrophy. The SCA7 CAG repeat was expanded in 77
patients and in 11 at-risk individuals, with alleles containing from 37 to
130 repeats, demonstrating that SCA7 is genetically homogeneous. Repeats on
normal alleles contained from 7 to 35 CAGs. There was a strong negative
correlation (r = -0.84) between the age at onset and the size of the CAG
repeat expansion in SCA7 patients. Larger expansions were associated with
earlier onset, a more severe and rapid clinical course, and a higher
frequency of decreased vision, ophthalmoplegia, extensor plantar response
and scoliosis. The frequency of other clinical signs such as dysphagia and
sphincter disturbances increased with disease duration. The mutation was
highly unstable during transmission, with a mean increase of 10 +/- 16 CAG
repeats, which was significantly greater in paternal (15 +/- 20) than in
maternal (5 +/- 5) transmissions. This correlated well with the marked
anticipation (19 +/- 13 years) observed in the families. Gonadal mosaicism,
observed in the sperm of a patient, was particularly important, with
expanded alleles ranging from 42 to >155 CAG repeats. The degree of
instability during transmission, resulting mostly in expansions, is greater
than in the seven other neurodegenerative disorders caused by polyglutamine
expansions.
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