Improved detection of amyloid in fat pad aspiration: an evaluation of Congo red stain by fluorescent microscopy

Amyloid fat pad aspiration specimens for cases with a clinical suspicion of amyloid typically are stained with Congo red and examined by brightfield microscopy. Congophilia with apple-green birefringence by polarization microscopy (PM) is considered diagnostic for amyloid. Examination of Congo red-stained slides by fluorescent microscopy (FM) is considered by some to be a more sensitive detection method. In this study, we assessed the utility of this technique in cytopathology archival slides from abdominal fat pad aspirations previously stained with Congo red dye. Seventy-eight cases of abdominal fat pad aspirations collected during the last 5 yr and stained with the Congo red procedure were obtained from archival files. Additionally, 20 adipose tissue material slides prepared from the surgical pathology specimens were examined as controls. One representative smear was examined in each case using FM equipped with rhodamine excitation/absorption (540/570 nm) filters. Relevant clinical information was obtained in all cases. Twelve cases (15.4%) of the 78 fat pad aspiration cases were reported originally as positive by Congo red stain using polarization and apple-green birefringence as diagnostic criteria. On review, four cases were deemed unsatisfactory. By FM examination 29 of the 74 (39.2%) cases were reclassified as positive for amyloid. The results were confirmed by immunohistochemical stain for amyloid P protein and electron microscopy. A number of similar distinct fluorescence and immunohistochemical patterns were recognized in the positive cases. Minimally weak fluorescence in the adipose tissue was observed in the control cases. The use of FM in Congo red-stained fat pad smears can improve the detection of amyloid in cytology preparations.     

Disease-specific electrophysiological findings in adult ceroid-lipofuscinosis (Kufs disease)

Two adults with mild dementia and a history of memory loss and disequilibrium were seen in the eye clinic following complaints of acuity loss in the 20/30–20/70 (Snellen) range. Results from the fundus examination of one patient were entirely normal; the other showed minimal vascular attenuation and optic atrophy. Electrophysiology was remarkable: (1) Photopic ERG b-waves were reduced, delayed, and showed pronounced oscillations. (2) EOG light-rise potentials were absent or very small. (3) Binocular pattern-VER signals showed addition of the monocular signal. Scotopic ERG signals were normal. Brain biopsy and microscopy showed intercellular, autofluorescent ceroid deposits which provided a clear diagnosis of Kufs disease. Histology of model animal retinal cells show ceroid deposits in cell classes implicated by the human retinal signals. The cluster of electrophysiological results point toward early changes in the pigment epithelium and inner plexiform layer cells as a means of non-invasive diagnosis.     

Handling of biological samples in the determination of the anti-neoplastic drug mitomycin C

A study to ascertain suitable conditions for handling biological samples from patients, treated with the antibiotic mitomycin C (MMC), with the objective of improving the accuracy and reliability of the determination is described. Situations frequently occurring in medical practice are simulated to optimize procedures for reliable and reproducible sampling, sample treatment and determination of MMC. Continuation of drug partitioning in whole blood after sampling can be prevented by immediate cooling in ice before the separation of plasma from cells. The adjustment of the pH of urine samples is shown to be particularly important since a low urinary pH causes decomposition of MMC; moreover, it may decrease extraction recovery. Furthermore, long-term exposure of samples to daylight induces drug decomposition. Frozen storage of plasma and urine samples for periods greater than 3 weeks is to be avoided as this results in a considerable drop in MMC concentration. Repeated cycles of freezing and thawing are shown to have no effect upon the analytical results (6 cycles tested). The analysis of extracts of biological samples may take place up to at least 24 h after their preparation without measurable loss of analyte.     

Partial cytochrome oxidase deficiency without subsarcolemmal accumulation of mitochondria in chronic progressive external ophthalmoplegia

Chronic progressive external ophthalmoplegia (CPEO) associated with proximal myopathy and/or craniosomatic abnormalities is a rare syndrome in which morphological mitochondrial changes have been found in some fibres (subsarcolemmal accumulation of mitochondria or "ragged red" fibres). We report a 14-year-old boy with CPEO and a mild proximal myopathy without these characteristic "ragged red" fibres. Histochemistry of skeletal muscle showed a mosaic of fibres without detectable cytochrome oxidase activity, while other mitochondrial enzymes were normal. The total cytochrome oxidase activity and cytochrome aa3 concentration in muscle mitochondrial fractions were only 40% of normal. This case is unique in that a biochemical defect was not accompanied by morphological abnormalities and may represent an early stage of CPEO before the development of morphological changes, or alternatively, a new variant of the disease.     

The optokinetic nystagmus and ocular pigmentation of hypopigmented mouse mutants

We tested the optokinetic nystagmus (OKN) reflex of various hypopigmented mutant mice and ultrastructurally examined the pigmentation of various ocular structures in these mutants. Using electron microscopy we examined the pigmentation of the choroid and retinal pigment epithelium (RPE) and measured the numerical density, volume density, and distribution of RPE melanosomes of mice with the following phenotypes: (1) wild type, (2) mutants that have abnormal or no OKN in response to horizontally moving, full-field stimulation, and (3) other mutants that have normal OKN but reduced choroidal pigmentation. We also measured the OKN of all these mice in response to horizontally moving stimuli that were restricted to the nasal or to the temporal retina. We found that in the mutants with normal OKN the numerical density of melanosomes in the RPE was within the range found for wild type, while the numerical density was reduced for the mutants with abnormal OKN. For one mutant with normal RPE pigmentation and normal OKN, the choroidal pigmentation was nearly absent. For the genotypes with abnormal OKN the volume density of the RPE melanosomes and percent apical melanosomes were sometimes greater and sometimes less than normal. The OKN patterns of these mice fell into the following categories: (1) wild type; (2) field-restriction dependent OKN with small following movements but no OKN in response to full-field stimulation, normal OKN in response to stimulation of the nasal retina, and OKN of reversed direction in response to stimulation of the temporal retina; (3) oblique with slow oblique following movements and reduced numbers of OKNs with oblique quick phases in response to horizontally moving, full-field stimulation, nearly normal OKN in response to stimulation of the nasal retina, and OKN of reversed direction in response to stimulation of the temporal retina. The horizontal component of the oblique response to full-field stimulation was in the same direction for the two eyes, but the vertical component was in the opposite direction. (4) Slow, small amplitude, with no or very small following movements in response to full-field stimulation, following movements in response to stimulation of the nasal retina and reversed "following" movements in response to stimulation of the temporal retina but few or no quick phases of the OKN for any stimulus condition. These results show that a variety of abnormalities of the OKN occur for hypopigmentation mutants of the mouse.(ABSTRACT TRUNCATED AT 400 WORDS)     

The distribution of (-)-propranolol in the isolated rabbit iris

It has been postulated that propranolol lowers the intraocular pressure by adrenergic neurone block. However, in the isolated iris of albino rabbits, there was only a small degree of cocaine-sensitive (i.e., neuronal) accumulation of ³H-(-)-propranolol, and none at all after pretreatment of the animals with reserpine. Moreover, after preloading of the iris with ³H-(-)-propranolol, veratridine failed to release any labelled material. Hence, any adrenergic neurone blocking action of propranolol is highly unlikely.Albino and pigmented irides were first exposed to ³H-(-)-propranolol and then washed out. The results and their compartmental analysis indicated an extensive binding of ³H-(-)-propranolol in or at pigment cells; the binding is characterized by a low dissociation constant. It is very likely that the initial binding and the subsequent slow dissociation from pigment cells explains the long duration of action of beta-adrenoceptor antagonists in human therapy.     

Hyperosmolarity response of ocular standing potential as a clinical test for retinal pigment epithelium activity normative data

The standing potential of the eye is decreased by intravenous administration of hypertonic solutions. This hyperosmolarity-induced response has been recorded in normal subjects by the use of electro-oculography (EOG) in the dark. An intravenous administration of Fructmanit^® (1.4 × 10³ mOsmol) (150 500ml, 2.37 9.70ml/kg, 0.08 0.36 ml/kg/min) was used to evoke the hyperosmolarity response. The amplitude of the response was expressed in percentage, V₀ – V_min/V₀ × 100, where V₀ is the base value of the EOG before administration of the hypertonic solution and V_min is a minimum EOG amplitude after administration. The distribution of the amplitude of the hyperosmolarity response was approximated by the normal distribution in normal subjects. The minimum, the maximum, the mean and the standard deviation of the amplitude of the hyperosmolarity response were respectively 34.2%, 52.3%, 42.6% and 4.6% in normal subjects. The normal range of the hyperosmolarity response would be 33.4 51.8% (M ± 2SD). The hyperosmolarity response, which originates mainly in the retinal pigment epithelium, is a useful new quantitative and specific test of the activity of the retinal pigment epithelium in clinical practice.     

一起赤潮后海产品麻痹性贝类毒素衰减结果分析

目的 以2017年漳州沿海一起赤潮引起的麻痹性贝类毒素(paralytic shellfish poisoning,PSP)中毒事件为研究起点,研究贝类海产品中的PSP在自然条件下的衰减情况。方法 在漳浦佛昙和龙海港尾海域采集牡蛎和贻贝进行PSP检测。结果 2017年6月8日相关海域海产品最大毒素总毒力为21 056.7 μg/kg,2017年6月26日海产品PSP总毒力值衰减86%以上,2017年7月20日海产品PSP总毒力值衰减97%以上,2018年12月所有海产品中PSP均未检出。结论 本次赤潮发生后,漳浦佛昙和龙海港尾两个海域贝类海产品约需45天净化周期方可食用,相关海域约需18个月净化至贝类毒素完全消失。     

新疆和田红葡萄体外抑制肿瘤作用的研究

目的：研究和田红葡萄体外抑瘤效果。方法：采用体外细胞培养方法观察和田红葡萄与红葡萄皮的醇提液对四株细胞株。即：正常小鼠成纤维细胞株（3T3）、胃癌细胞株（MGC－803,NKM）和肝癌细胞株（Q3）细胞存活率及蛋白质含量影响。结果：（1）和田红葡萄醇提液与和田红葡萄皮醇提液都显著抑制NKM和Q3存活（P＜0．01）,后者对MGC－803存活率亦显著影响（P＜0．01）,最强作用浓度0．01g/ml。两种醇提液作用于NKM、Q3、MGC－803的抑制率分别为11．0％、14．0％、24．0％。葡萄皮醇提液抑瘤效果强于葡萄醇提液（P＜0．05）;（2）两种醇提液皆对细胞蛋白质含量无影响（P＞0．05）;（3）葡萄醇提液促进3T3生长作用较葡萄皮醇提液强（P＜0．05）。结论：和田红葡萄可能具有一定的体外抑癌作用。     

Intraosseous Regional Administration of Vancomycin in Primary Total Knee Arthroplasty Does Not Increase the Risk of Vancomycin-Associated Complications

BackgroundPeriprosthetic joint infection (PJI) after total knee arthroplasty (TKA) is a rare but major complication. Owing to an increasing antibiotic resistance in bacteria causing PJI, vancomycin has been investigated as a prophylactic agent. Intraosseous regional administration (IORA) of vancomycin achieves significantly higher local tissue concentrations than systemic administration. There are limited data on IORA of vancomycin with respect to vancomycin-associated complications.MethodsSingle-surgeon retrospective review of primary TKA was performed between January 2015 and May 2019. All patients received 500 mg of IORA of vancomycin after tourniquet inflation and 3 × 1 g intravenous cefazolin in 24 hrs. Preoperative data collected included age, gender, body mass index, American Society of Anesthesiologists (ASA) score, diabetes, and chronic kidney disease (CKD). We documented in-hospital complications and complications requiring readmission within 12 months. Primary outcome measures were the incidence of acute kidney injury (AKI), ‘red man syndrome’ (RMS), and neutropenia. The secondary outcome measure was PJI incidence.ResultsWe identified 631 primary TKAs in 556 patients, of which 331 received IORA. The mean age was 67.7 ± 8.7 years, and 57.8% were women. CKD was prevalent in 17.2% of the cohort. AKI occurred in 25 (3.9%) cases. After controlling for covariates, CKD was the only significant predictor of AKI (odds ratio = 3.035, P = .023). RMS and neutropenia were not observed in this cohort. The 90-day PJI rate was 0%, and the 1-year PJI rate was 0.2%.ConclusionsLow-dose IORA of vancomycin in addition to standard intravenous systemic cefazolin prophylaxis in TKA is safe without significant adverse effects of vancomycin such as AKI, RMS, or neutropenia.