应用激光扫描共聚焦显微镜观察晶体上皮细胞中的游离钙

目的用钙的荧光指示剂ｆｌｕｏ－３和激光扫描共聚焦显微镜（ｌａｓｅｒｓｃａｎｎｉｎｇｃｏｎｆｏｃａｌｍｉｃｒｏｓｃｏｐｙ，ＬＳＣＭ）观察大白鼠的晶体上皮细胞（ｌｅｎｓｅｐｉｔｈｅｌｉａｌｃｅｌ，ＬＥＣ）中的游离钙。方法ｆｌｕｏ－３着染细胞后，应用ＬＳＣＭ观察细胞内ｆｌｕｏ－３与钙螯合后的荧光分布，最后用钙离子载体Ａ２３１８７和重金属离子Ｍｎ＋＋作校正，将ｆｌｕｏ－３与钙结合显示的荧光强度转换为［Ｃａ＋＋］ｉ值。结果ＬＥＣ中的游离钙主要分布在细胞核中。大白鼠晶体上皮细胞中的［Ｃａ＋＋］ｉ为２５９．７９±４９．２４ｎｍｏｌ／Ｌ。结论ｆｌｕｏ－３与ＬＥＣ孵育后能着染细胞。用ＬＳＣＭ能直观地观察细胞内钙的分布，并能通过校正得到细胞内游离钙的绝对值。这种成熟的方法，为进一步对ＬＥＣ中游离Ｃａ＋＋的研究提供技术准备     

Local variations in the cerebral microcirculatory response to hypercapnia and haemorrhage

Summary This study evaluates local variations of the cerebral vasomotor responses to hypercapnia and haemorrhagic hypotension in a pig model. Four laser Doppler flow probes were used in each pig. There was considerable variation in laser Doppler signals between the four probes in baseline recordings. The increases in flow after CO₂ administration in 7 pigs had a mean coefficient of variation of 0.43 ± 0.31, and the flow changes after blood loss in another 7 pigs had a mean coefficient of variation of 0.45 ± 0.34. The range of flow changes within each animal was large; the probe with the highest CO₂ response showed on the average a 273% ± 157% larger CO₂ response than the probe with the lowest CO₂ response. Correspondingly, the probe with the best preserved blood flow after blood loss had on the average a flow value of 93% ± 12% of the baseline value, while the probe that changed most with haemorrhage had a flow value of 44% ± 24% of the baseline value. Single laser Doppler recordings have been used for the monitoring of cerebral blood flow in neurosurgical critical care, but our results suggest that a single laser Doppler flow probe is not an adequate method to monitor vasoreactivity in neurosurgical patients because flow signals from one probe may be unrepresentative for other sites in the brain.     

革兰氏阴性杆菌发生过程控制的研究

本研究选择奇异变形杆菌和绿肿杆菌等作为实验体系，从群体发生发展过程的宏观表现上探讨了生物控制的时空表达及非线性问题。结果表明，杆菌发生过程的时相周期性可以表现为空间的波形靶图样，并具有分形的特征。实验结果表明，菌群在生长过程中的代谢产物是富含生物信息的控制中介机制。我们认为，生物系统局部存在着准平衡和准封闭的微生态环境，生物液晶的存在和相变是细菌群体发生过程的重要协同中介因素。     

The anterior inferior cerebellar arterial network supplying the rat cochlea and its role in autoregulation of cochlear blood flow

Summary The sensitivity of the cochlea is dependent upon maintenance of a delicate homeostatic environment. One mechanism which participates in providing this environment is the autoregulation of cochlear blood flow. This autoregulation is ensured through the interaction of sympathetic, peptidergic and hemodynamic mechanisms. The current study demonstrates an adaptation that also participates in cochlear blood flow autoregulation. Specifically, an anterior inferior cerebellar arterial network is described and the relative contributions of each of its vessels to total cochlear blood flow is measured using laser Doppler flowmetry. The results show that each collateral vessel contributes to the blood supply of the cochlea and that reperfusion is accompanied by hyperemia. These findings suggest an adaptation that provides stable blood flow through redundancy and compensatory potential. Additionally, these observations have implications for experimental models of ischemia.     

激光光凝联合玻璃体腔注气治疗玻璃体切割术后再发黄斑孔

目的 探讨激光光凝联合玻璃体腔注气治疗玻璃体切割术后再发与未愈黄斑孔的疗效。方法 应用COHERENT Omni多波长激光光凝黄斑裂孔底部的视网膜色素上皮层。随后眼内注入20％C3F80．5～0．8ml并置换出玻璃体腔液体。治疗后每天坚持俯卧位。结果 19只眼中16只眼黄斑孔愈合，成功率为84．2％，视力提高15只眼，占78．9％，未出现严重的并发症。结论 应用激光光凝联合眼内注气治疗玻璃体切割术后再发与未愈黄斑孔具有方法简单、费用低、疗效确定、大部分患者无须住院等优点。     

Quantitative and comparative study of haematoporphyrin-derived photosensitizers on a murine tumour model

Eight commercially available HPD-photosensitizers intended for photodynamic therapy were tested in a murine tumour model with regard to their therapeutic efficacy. The regrowth delay of the fibrosarcoma SSK-2 on the mouse C3H, Neuherberg-line, was determined 3, 24, 48 and 72 h after injection of the drugs (dose: 9 mg kg^–1 body weight). The corresponding pharmacodynamics, as measured by regrowth delay, were approximated by an exponential function and the characterizing coefficients derived. These coefficients served to quantify the photodynamic properties of the drugs.The pharmacodynamics of five substances were compared with those obtained fluorometrically. The latter showed shorter decay constants than the therapy-correlated substances which indicates different metabolic behaviour of the therapeutic and diagnostically useful fluorescent components of haematoporphyrin-derived photosensitizers.     

Initial experience with carbon dioxide laser laparoscopy

Adhesions and endometriosis are commonly encountered among patients presenting with pelvic or lower abdominal pain and also in a significant proportion of infertile patients. Laparoscopic investigation is usual in patients with these problems, and it has been possible to perform endoscopic surgery with special scissors and electrodiathermy. These methods can cause troublesome bleeding, and the diathermy produces high temperatures which can be hazardous if used in the vicinity of the bowel. The carbon dioxide laser can be used endoscopically to vaporize deposits of endometriosis and adhesions with great precision and virtually no bleeding. One hundred consecutive patients with endometriosis or adhesions were treated with the CO₂ laser laparoscope and followed up for at least a year. Seventy-five per cent of patients with pain due to endometriosis were cured, and 68% of patients were better after laser laparoscopic adhesiolysis. Pregnancy rate in the previously infertile group with endometriosis was 64%. There were no complications due to the intra-abdominal use of CO₂ laser energy under endoscopic control, although there is a need for a controlled trial. It appears that in the hands of an experienced laparoscopist this technique is safe and effective.     

激光光凝治疗黄斑水肿

应用氩绿激光治疗视网膜血管性疾病所致黄斑水肿50例,73只眼。治疗后,有20.5％(15/73)的患眼视力提高2行以上,76.8％(56/73)的患眼视力保持稳定。局部性和/或非囊样黄斑水肿患眼的视力预后较好,水肿易于吸收。弥漫性和/或囊样黄斑水肿患眼的视力预后较差,水肿较难吸收。术前视力可影响预后。对激光光凝治疗本病的疗效、影响因素、激光治疗技术及其机理,也进行了讨论。     

Identification of N2 as a metabolite of acetylhydrazine in the rat

 In the pathogenesis of isoniazid-induced hepatic injury, cytochrome P450-dependent metabolic activation of the metabolite, acetylhydrazine (AcHz), is the crucial step. Exhalation of [¹⁴C]-carbon dioxide has previously been used to quantify indirectly this pathway. In contrast, according to the current concept of AcHz bioactivation, molecular nitrogen is produced directly, but has not yet been identified. Here, we measured [¹⁵N]-nitrogen and ¹⁴CO₂ exhalation, after the administration of [¹⁵N₂]-[¹⁴C]-AcHz, in rats. Laser magnetic resonance (LMR) spectroscopy, a new sensitive and specific technique for the measurement of ¹⁵N and ¹⁴N in gas samples, was used. To demonstrate the involvement of cytochrome P450, rats were treated with phenobarbital (PB) or PB + cobalt(II) chloride (CoCl₂) (n=3 in each group). Time-dependent ¹⁵N₂ exhalation differed significantly between treatment groups (p<0.001). At 240 min, cumulative exhalation of ¹⁵N was 1.92±0.43% (mean±SE) of the dose in the control group, 2.53±0.23% in the PB group, and 1.00±0.15% in the PB+CoCl₂ group (p<0.05 compared to controls, p<0.01 compared to PB). Cumulative exhalation of ¹⁴CO₂ in 24 h ranged from 15.1 to 21.9%, with no significant difference between treatment groups. In conclusion, N₂ is a metabolite of AcHz. N₂ formation reflects the cytochrome P450-mediated activation of AcHz and can be used as an index of this pathway. Generally, LMR spectroscopy is valuable for monitoring any N₂-liberating process in vivo. Received: 14 March 1995/Accepted: 15 August 1995     

Techniques in facial identification: Computer-aided facial reconstruction using a laser scanner and video superimposition

A facial image was reconstructed from the skull, part of a complete skeleton found in woodland, of a male person who had hanged himself from a tree. In addition, video superimposition was carried out with antemortem photographs of a person suspected of being the victim, and a good match was obtained. In a further case, a cheaper video-transparency superimposition was carried out, with identity later being confirmed on the basis of dental records. The techniques and the problems encountered are discussed. According to our experience, 3D computer reconstruction and video superimposition have a useful role in the process of identification, particularly in the early stages of an investigation and when other more definitive methods may not be available.