烧热病的病因研究

烧热病是20余年来发生于我国部分棉产区农村的一个新病种。我们通过对全国主要发病地区广泛的病因调查,并结合临床观察、实验研究和预防实践,终于查明本病是较长期大量食用粗制生棉油(其主要毒性成分为棉酚)所致的慢性中毒性疾病。本文介绍了病区粗制生棉油制油工艺的三种类型;并论述了确定本病病因的主要根据。     

Regional differences in the pineal gland of the cotton rat, Sigmodon hispidus: Light microscopic, electron microscopic, and immunohistochemical observations

Abstract: Light microscopic, electron microscopic and immunohistochemical observations of the various portions of the pineal gland of the cotton rat ( Sigmodon hispidus ) were made. The volume of the proximal half occupied about 30% of the whole organ, and pinealocytes were slightly smaller in size in the proximal portion than elsewhere. The distal and intermediate portions contained few interstitial cells and numerous astrocytes, but the proximal portion lacked interstitial cells and had more abundant astrocytes than elsewhere. Astrocytes, which were immunoreactive for glial fibrillary acidic protein, mainly lined the pericapillary spaces in the distal and intermediate portions, but in the proximal portion these cells often surrounded isolated or groups of pinealocytes. In the distal and intermediate portions, abundant sympathetic fibers and less numerous non-sympathetic, peptidergic fibers were mainly localized in the pericapillary spaces; these fibers were sparsely distributed in the parenchyma close to interstitial cells or astrocytes. In the proximal portion, non-sympathetic fibers were scarce and sympathetic fibers were distributed abundantly and almost exclusively in the parenchyma. Most of the sympathetic fibers were adjacent to astrocytes and, occasionally, made specialized contact with them. Fenestrae in the capillary endothelium were numerous in the distal portion but absent in the proximal portion. Thus, marked differences in structure existed between the distal and proximal portions of the pineal gland of the cotton rat, suggesting that both portions are functionally dissimilar. In addition, the present study indicates that the proximal portion of the cotton rat was well developed and showed morphological features similar to the deeply situated pineal glands of other mammals.     

Antral Red Streaking is a Negative Endoscopic Sign for Helicobacter Pylori Infection

Background: One of the most important endoscopic findings for the diagnosis of chronic gastritis is erythema. Erythema is classified into two groups: spotted or scattered erythema and linear erythema. We feel that red streaking has a tendency to be found on the apparently normal gastric mucosa without inflammation. Methods: To evaluate this association prospectively, we conducted the present study in 1513 consecutive patients undergoing endoscopy. Helicobacter pylori infection was assessed by rapid urease test, culture, pathological test, serological test and urea breath test using ¹³C. Results: Of these patients, red streaking was recognized in 94 patients (6.2%). All of the tests showed very low prevalence (0–3.5%) of H. pylori infection in patients with red streaking whereas positive results were obtained recognized in 42–49% of 94 age‐sex‐matched patients without red streaking. Additionally, no peptic‐ulcer diseases, such as gastric ulcer/ulcer scar and duodenal ulcer/ulcer scar, were found in the patients with red streaks. In conclusion, red streaking is a negative sign for H. pylori infection and peptic‐ulcer diseases. Conclusions: The understanding of these results might also improve the effort and cost‐effectiveness of endoscopic examinations by avoiding unnecessary further testing.     

Occupation and pancreatic cancer risk in Louisiana

To study the relation of occupational exposures and pancreatic cancer, we evaluated data from males (198 cases and 209 controls) participating in a hospital-based case-control study conducted in a high-risk area of Louisiana between 1979 and 1983. The questionnaire obtained information on lifetime occupational history, as well as dietary, smoking, and drinking habits and demographic characteristics. After adjustment for smoking and dietary patterns, white collar occupations showed consistent elevations in risk, whereas associations for other occupations were in general unremarkable. Although not significantly elevated, risks for truck drivers (OR = 1.7) and those with long-term employment in machine repair or as mechanics were suggestive (OR = 2.5). No association was found for jobs in oil refining or oil and gas extraction (ORs were 0.5 and 0.4, respectively), although risks were slightly elevated for long-term workers in the chemical processing industry (OR = 1.2). While these associations deserve further study, our findings are consistent with results of other studies which do not suggest that occupational exposures are important determinants of pancreatic cancer.     

Respiratory and nonrespiratory morbidity in a titanium oxide paint factory in Nigeria

A study of 67 subjects in a small titanium oxide paint factory in Nigeria showed 50-54% frequency for airway symptoms, 20-40% for neurological symptoms, and 10-27% for other symptoms. The symptoms were well correlated with exposure (p less than .05) and pulmonary function tests (PFTs). The directly exposed subjects had likelihood odds ratios of 5 to 17 of presenting symptoms compared to controls. The PFT deficit, relative to the expected value, was significantly higher for those with airway symptoms than for those of other symptom categories (p less than .005). There were 28 (42%) cases of restrictive lung impairment. Exposure to cotton dust had confounding influence on the PFT of subjects previously exposed. Smoking rate was very low. These findings indicate the need for worker protection in a manufacturing plant in Nigeria.     

Retinal ganglion cell death during optic nerve regeneration in the frog Hyla moorei

In the frog Hyla moorei we have estimated there to be between approximately 450,000 and 750,000 cells in the retinal ganglion cell layer. Optic axon counts and retrograde transport of horseradish peroxidase (HRP) indicated that 72-76% of these were ganglion cells. Cells of this type were distributed as a temporally situated area centralis within a horizontal visual streak. Cell and optic axon counts showed that there was an approximately 40% loss of ganglion cells during optic nerve regeneration. Ganglion cells appeared chromatolysed by 6-8 days after an extracranial nerve crush but there was no indication of cell death until 15 days. By this stage anterograde transport of HRP indicated that axons had reached the chiasma. Death was first seen in the area centralis, extended along the streak, and finally was observed in the periphery by 65 days; cell counts demonstrated that at this time the wave of death was almost complete. We have previously shown by electrophysiological visual mapping (Humphrey and Beazley, '82) and confirmed in this study that visuotectal projections were retinotopically organized during regeneration. Multiunit receptive fields were initially large but progressively refined starting in nasal field (temporal retina) to restore a normal projection. The similar sequences whereby the visuotectal projection became refined and death took place in the retinal ganglion cell layer suggested that death may be related to a process of organization within the regenerating projection. In normal animals primary visual pathways revealed by anterograde transport of HRP were essentially similar to those of Rana pipiens and R. esculenta. Regenerating axons generally remained within optic pathways. Exceptions were a retinoretinal projection which was not completely withdrawn even after 1,028 days and a direct projection to the ipsilateral tectum via an inappropriate part of the optic tract.     

体外产气法对苏丹草与棉秆间组合效应的研究

为了探讨苏丹草(Sudan Grass,SG)与棉秆(Cotton Straw,CS)在瘤胃发酵中的组合效应,本研究将苏丹草与棉秆以100∶0、75∶25、50∶50、25∶75、0∶100比例进行组合,每个组合3个重复,利用瘤胃液体外发酵技术,分析GP(产气量)、pH值、瘤胃液NH3-N(氨态氮)和VFA(挥发性脂肪酸)含量,评价产气量组合效应以及综合组合效应。结果表明:(1)苏丹草和棉秆比例为50∶50和25∶75时,产气量与产气速率较高。(2)24~72h阶段50∶50和25∶75组的组合效应均为正值,且25∶75组的组合效应值最高。(3)苏丹草与棉秆不同比例的组合中,25∶75的组合产生的组合效应最高。     

Topography of ganglion cells in the dog and wolf retina.

The topographical distribution of retinal ganglion cells in seven breeds of dog (Canis lupus f. familiaris) and in the wolf (Canis lupus) was studied in retinal wholemounts stained with cresyl violet or with a reduced silver method. A prominent feature of all wolf retinae was a pronounced "visual streak" of high ganglion cell density, extending from the central area far into both temporal and nasal retina. By contrast, either a pronounced or a moderate visual streak was found in dog retinae. It is hypothesized that a pronounced streak is an archetypal feature of Canis lupus, and that the moderate streak in some dogs is a corollary of breeding during domestication. Irrespective of the differences in streak form and retinal area, the estimated total number of ganglion cells was about 200,000 cells in the wolf and 115,000 in the dog. Ganglion cell density maxima in the central area of the wolf were about 12,000-14,000/mm2, and in the dog they ranged from 6,400/mm2 to 14,400/mm2. This implies individual differences in visual acuity. Alpha ganglion cells constituted 3-14% of all ganglion cells in the dog and 1-18% in the wolf, depending on retinal location. A distinct feature of all dogs and wolves was the absence of alpha cells in a substantial region of temporal peripheral retina. This has not been found in any other mammalian species and suggests corresponding functional deficits.     

Medical and industrial hygiene characterization of the cotton waste utilization industry

We studied 260 workers in the cotton waste utilization industry and 310 "blue-collar" control workers from nondusty industries in the same geographic area of the United States by respiratory symptom questionnaire and by pre- and postshift spirometry. We excluded 75 cotton workers and 75 control workers from statistical analysis because of prior hazardous occupational exposures. Plant-wide, 8-hour time-weighted average exposures ranged from 0.28 mg/m3 to 7.80 mg/m3. The overall prevalence of symptoms compatible with byssinosis was 5.9% in cotton workers and 4.7% in the controls. Cotton workers with less than 2 years of employment had a significantly greater prevalence of bronchitis than their control counterparts. The cotton workers with 2 years or more of employment had significantly greater prevalences of bronchitis, shift decrement in forced expiratory volume in 1 second (FEV1) of greater than or equal to 10%, and FEV1/FEV1-predicted less than 80%, than their control counterparts. Regression analysis showed that for matched cotton and control workers, the percentage decrement in FEV1 over the shift was significantly greater for cotton workers; and that in all cotton workers, longevity in industry had a negative effect on the before-shift forced vital capacity (FVC). This study suggests that there are both acute and chronic effects of cotton exposure in the cotton waste utilization industry.