污水中汞的微波消解冷原子吸收测定法

目的 改进冷原子吸收法测定污水中汞的消解方法。方法 采用王水（1＋1）微波消解法代替KMnO4-K2S2O8消解法测定污水中的汞。结果 王水（1＋1）微波消解水样测定污水中汞，方法的线性范围为0~10.0μg／L，检出限为0.25μg／L，相对标准偏差小于2.7％，加标回收率为95.0％-102.0%。结论 与KMnO4-K2S2O8消解法相比，该方法具有较高的灵敏度和精密度，操作简单，结果可靠，适用于环境监测分析。     

Peptic ulcer and gastric carcinoma: diagnosis with biphasic radiography compared with fiberoptic endoscopy

The diagnostic value of biphasic radiographic examination of the stomach and duodenum was compared with that of fiberoptic endoscopy in a prospective, blinded study of 385 patients with dyspepsia. This investigation was directed at gastric malignancies and peptic ulcers. Methodologically there is no absolute standard for a study of this kind because histologic examination is useful for detection of cancer but inadequate for ulcers. As an alternative, kappa indexes and the sensitivity and specificity, as derived by Hui and Walter, were calculated and compared. For the detection of gastric carcinoma, radiographic and endoscopic findings had almost perfect agreement beyond chance. For gastric ulcers, radiography and endoscopy had substantial agreement, which became perfect if small ulcers (less than 5 mm) were excluded. For duodenal ulcers, radiography had a lower sensitivity than endoscopy; this disagreement disappeared if small ulcers were excluded. Both methods have equal merit; choice of the initial diagnostic procedure will therefore depend on cost, discomfort to the patient, and risk of complications.     

Effect of isepamicin dosing scheme on concentration in cochlear tissue.

To investigate the possible effect of the dosing scheme of aminoglycosides on their concentration in the cochlear tissue, we gave two groups of 12 guinea pigs subcutaneous doses of 45 mg of isepamicin (ca. 30 mg of active product) per kg of body weight daily for eight consecutive days. The first group received the drug by continuous infusion, while the second group received it by single daily injection. On the final day of administration, the animals were sacrificed and the cochlear tissue was removed. The tissues from the cochleas of pairs of guinea pigs were pooled. The isepamicin concentrations in the cochlear duct tissue (organ of Corti plus lateral wall) and the cochlear nerve tissue were determined separately. Hearing levels before and after treatment were assessed by means of frequency-specific auditory brain stem responses (ABR). The creatinine level in serum was determined on the last day of the administration. None of the animals in either group showed signs of renal insufficiency or of hearing impairment. The median isepamicin concentration in the cochlear duct was 2.40 micrograms/mg of protein after continuous administration and 2.50 micrograms/mg of protein after once-daily administration, compared with the concentration in the cochlear nerve, where it was 1.93 micrograms/mg of protein after continuous administration and 2.59 micrograms/mg of protein after once-daily administration. These differences are statistically insignificant. The results give evidence for linear uptake kinetics of isepamicin in the inner ear tissue and may be directly relevant to the clinical dosing of the drug.     

Parathyroid imaging: comparison of double-tracer (T1-201, Tc-99m) scintigraphy and high-resolution US

Parathyroid scintigraphy using a double-tracer (T1-201, Tc-99m) subtraction technique depicted 17 of 23 (74%) parathyroid adenomas in patients with and without previous neck operations. High-resolution (10-MHz) ultrasound (US) depicted 18 (78%) of these adenomas. Average tumor size depicted by US was 17 X 10 X 8 mm (excluding a giant adenoma) and 19 X 10 X 9 mm by scintigraphy. Alone, neither modality was particularly sensitive in the depiction of primary hyperplasia of the parathyroid glands, but combined techniques were more effective than the use of a single modality. With both US and T1-201 scintigraphy, only two of 23 cases of parathyroid adenoma in the neck were missed, and none of the eight cases of secondary hyperplasia were missed. In 11 patients who had previously undergone neck surgery, parathyroid tumors were identified in eight by either US or double-tracer scintigraphy. Preoperative parathyroid imaging with double-tracer scintigraphy and high-resolution US is suggested for patients with hyperparathyroidism, particularly in those patients who have had previous parathyroid surgery.     

Enzyme immunoassay of human placental and germ-cell alkaline phosphatase in serum.

Placental alkaline phosphatase (placental ALP, PLAP) and germ-cell ALP (GCAP, also known as placental-like ALP), expressed in gonadal cancer tissues, are potential tumor markers. Four monoclonal antibodies, raised against PLAP and recognizing different epitopes, were selected to study the influence of the following variables on the accuracy of PLAP and GCAP measurement: phenotype, molecular form, and glycation pattern of PLAP and GCAP; incubation temperature; and interferences by serum during immunobinding. Nine GCAP phenotypes were identified, interacting with each antibody at a lower affinity than was seen for the more common PLAP phenotypes. Antibody affinity is higher for the free hydrophilic dimeric forms of PLAP and GCAP, and is not influenced by the degree of glycation. In serum or tissue extracts, measurement of PLAP or GCAP is most nearly accurate when immunoincubations are performed at 37 degrees C, with use of antibodies 327 and 7E8, respectively. In addition, correct measurements are achieved only when, during immunobinding, serum is incubated with an equal volume of deoxycholate (9 g/L final concentration).     

Risk of Aluminium Intoxication in Long-term Acetate Redy Dialysis

Closed-circuit dialysis using the Redy sorbent cartridge toregenerate the dialysate has been incriminated in previous reportsas a cause of severe fracturing osteomalacia and fatal encephalopathyin several patients treated with this procedure for 15–36months. In a retrospective study, we compared 15 unselectedpatients who had received Redy dialysis for 66±14 monthswith 15 control patients dialysed with single passage of dialysate. Redy and control patients were matched for age, sex, and durationof dialysis. They belonged to two dialysis centres, situatedin the same geographical area and having a common water supply.Mean serum and bone aluminium concentrations were slightly greaterin the Redy group but the differences were not significant.Pathological fractures had occurred in two Redy patients andin one control, but could not be attributed to aluminium-inducedbone disease. Although the histochemical staining for aluminiumin bone was positive in six patients, diagnosis of aluminium-inducedbone disease was made in one case only. The results of bonehistomorphometry did not differ significantly between the twogroups. Our findings may be explained by the strict applicationof the measures required to avoid aluminium contamination ofthe Redy dialysate, i.e. sufficient rinsing before dialysis,use of almost aluminium-free water, and of acetate-buffereddialysate.     

Tumor-cell lysis by in-situ-activated human peripheral-blood mononuclear cells

A heteroconjugate (HC) was synthesized between OKT3 and monoclonal antibody (MAb) 7E8, which specifically reacts with the tumor marker placental alkaline phosphatase (PLAP). Similarly to OKT3, in vitro, the HC induced a dose-dependent proliferation response of human peripheral-blood mononuclear cells (PBMCs) and, in concert with rIL-2, it progressively activated T cells over a 4-day period. In co-cultures of continuously activated PBMCs and MO4 tumor cells (non-MHC-restricted mouse fibroblasts transfected with the cDNA for PLAP), the HC (25 ng/ml), again acting in concert with rIL-2, induced specific lysis of the MO4 cells. This process occurred progressively over 2 to 3 days and was monitored from the release in the supernatant fluid of cellular 3H-L-leucine, but also from analyses involving the remaining non-lysed cancer cells, i.e., by estimates of their protein content, by measurements of their viability, and most accurately by determinations of their PLAP content. Antibody 7E8 by itself induced a weak tumor-cell lysis (ADCC), potentiated by the addition of rIL-2. However, after 7 days of PBMC-preactivation with the HC and rIL-2, antibody 7E8 no longer mediated any ADCC, whereas the HC-dependent lysis was further potentiated. The observed proliferation of T cells and development of cytotoxicity at low concentrations of HC and rIL-2 support the idea that a moderate but continuous T-cell activation combined with T-cell targeting is sufficient for the induction of progressive and efficient tumor-cell lysis.     

Surgical management of adrenal disease

This study reviews the surgical management of adrenal disease over a 23 year period in a Dublin teaching hospital. Nineteen patients were diagnosed as having either Medullary or Cortical disease. Ultrasound and CAT Scan proved highly accurate in pre-operative tumour localisation. This analysis highlights the atypical presentation of phaeochromocytoma, the accuracy of Ultrasound and CAT Scan in tumour localisation and the importance of peri-operative monitoring.