生物化学技术

A 28-year-old man was transferred to our hospital and underwent surgery for resection of an aortic graft infected with Klebsiella pneumoniae. Antimicrobial therapy consisted of amikacin, cefazolin, chloramphenicol, sulfamethoxazole, and trimethoprim. A request for amikacin ...

Until recently, it was difficult to explain why an identical drug dosage may exert a toxic effect in one patient and a therapeutic, or no, response in another patient. It has now been demonstrated that the concentration of drug at the tissue receptor site is the most important parameter for adjusting dr ...

High performance liquid chromatography (HPLC) is one of the most rapidly growing and potentially largest branches of analytical chemistry. Although further advances in HPLC are to be expected, current methodology is already far enough advanced to insure its use in the clinical laborat ...

The polyamines spermidine and spermine and their diamine precursor, putrescine , have been the subject of intense study relative to their potential as tumor markers during the past decade (1). These compounds have been implicated in numerous biochemical reactions and have been clearly a ...

The presence of increased levels of various organic acids in physiological fluids such as serum, plasma, and urine has been correlated with a variety of diseases (1). Although some are rare, others such as lactic acidosis and hyperoxaluria are more widespread (2, 3). The estimation of organic acids ...

Historically the term porphyria has been used since it was coined in 1871 to describe a purple colored material extracted from pathological feces (1). The first case of porphyria was reported in 1874, (2, 3), but until the 1930 Nobel Prize winning work of Hans Fischer on the synthesis of protoporphyrin, ...

Because of the complexity of cellular material and body fluids, it is seldom possible to analyze a natural product directly. Qualitative and quantitative analyses must often be preceded by some purification step that separates the molecular species being examined from interfering ma ...

The amino acids tyrosine and tryptophan are precursors for a number of important physiological compounds. The catecholamines, which are metabolites of tyrosine, serve as neurotransmitters in the central and peripheral nervous systems. Serotonin, a major metabolite of tryptoph ...

Rapid identification and quantitation of drugs in biofluids are helpful to the physician in managing patients with suspected drug intoxication. Higgins and O’Brien (1) noted that prior to 1960, drug overdoses usually consisted of a single drug. However, three years later they observed that ...

In recent years, most large hospitals have observed a marked increase in the admission of patients suffering from drug overdose. Overdose of narcotic drugs, such as the opiates, represent less of a problem on a day-to-day basis than do overdoses of prescribed drugs, such as sedatives and hypnotics. ...

This article reviews the basic principles of high performance liquid chromatography (HPLC). The introductory section provides an overview of the HPLC technique, placing it in historical context and discussing the elementary facts of the separation mechanism. The next section disc ...

Cryopreservation is the ultra-low temperature storage (usually in liquid nitrogen at ca. -135 to -196�C) of living cells, tissues and organs capable of resuming normal functions after retrieval from a cryobank. This chapter explains the basic principles of cryopreservation with resp ...

Morphological examination of calcified structures, by either light microscopy (LM) or electron microscopy (EM) often requires a decalcification (decal) step after fixation. Further processing steps must await the completion of the decal process. The time required for full decal wi ...

The authors’ research focuses on the structural basis of synaptic function. Knowing the dimensions and connectivity of presynaptic and postsynaptic elements is necessary for understanding the mechanisms of synaptic transmission in the central nervous system. To this end, electr ...

Preparation of botanical specimens for electron microscopy (EM) is hampered by several physical factors unique to plant cells. Impediments to penetration and action of various reagents in the tissue preparation process include the vacuole, plastids, cell wall (CW), and intercellul ...

Microwave (MW) technology has found a permanent niche in the world of surgical pathology, biomedical research, and allied disciplines, for a few simple reasons: It can reduce the processing times for tissue samples destined for evaluation by light, scanning, or electron microscopy (EM); it is ...

Chemical (chem) fixatives and conventional fixation times, used for standardized preservation of tissues, can result in serious alterations to morphology, as a consequence of solubilization and conformational changes of proteins and lipids (Login and Dvorak, 1985). These untow ...

Acetylcholinesterase (AChE) is the modulating enzyme of cholinergic systems. Study of its morphological distribution and its pathophysiological disposition following disease or exposure to anticholinesterase compounds such as pesticides, organophosphates, and ch ...

降血脂药他汀类无论是之前成熟的发酵品种，还是当下发展迅速的全合成产品，一直是处于不断革新和改进的状态，特别是新的酶法工艺的发展，引领着市场的走势。从整体环境看，我国的环保、安全成本将继续逐步加大，人力成本持续上涨，这些必然的趋势所带来的，是所谓的“中国制造”优势的部分散失。目前全球包括美国在内，都在流行“制造业回归”，虽然和化学原料这种环境污染压力较大的品种情况会不一样，但印度开始大量输出洛伐他汀的情况，无疑是这样 ...

胆固醇可调节磷脂双分子层膜的流动性，使膜通透性降低，减少药物渗漏。同时可使脂膜维持一定柔韧性，增强脂质体囊泡抗击外部条件变化的能力。并对磷脂的氧化有一定保护作用。制备普通载药脂质体，胆固醇是必须的添加物，用量一般为CHO:PC=0.3~1（摩尔比）。因PC和药物的不同，存在胆固醇的最佳用量。在一定范围内，脂质体的粒径、氧化稳定性、物理稳定性与胆固醇添加量成正相关，超出范围时，超过膜负荷，会造成部分脂质体破裂。另外，胆固醇 ...