Israel Diamond

Ultrastructure of myeloma cells in a case with crystalcryoglobulinemia

The bone marrow of a patient with multiple myeloma of the IgG2 Kappa type with spontaneously crystallizing cryoglobulin was studied by electron microscopy. The ultrastructure of the myeloma cells disclosed the presence of a crystalline material in the cytoplasm within the rough endoplasmic reticulum (RER) as well as in extracisternal sites. The crystalline material was also seen extracellulary with a distinctly unique subunit structure. The tubular units measured 200 ± 10 AÅ (SEM) externally with an internal diameter of 100 ± AÅ (SEM). The intracellular distribution did not indicate a characteristic organelle association usually observed in protein synthesizing cells. It is suggested, based on the present observations and the findings of others, that the crystalline material may represent polymerized protein synthesized by free ribosomes mostly in extracisternal locations, a pattern often seen in neoplastic plasma cells. Diffusion to extracisternal sites of precrystalline material through the membranes of the RER is a possible alternative mechanism.

Ultrastructure of fallopian tube carcinoma

Fallopian tube carcinoma is one of the rarest of primary gynecologic malignancies. Normal tubal epithelium is composed of secretory, ciliated, and intercalary cells. To determine the cellular composition and ultrastructural details of this rare neoplasm, a moderately well‐differentiated tubal carcinoma was studied with the electron microscope. A prominent feature was the formation of numerous ultramicro alveolar spaces lined by cell surface microvilli. The nuclei of the neoplastic cells demonstrated a variety of fine structural abnormalities. Based on cell size and shape criteria, a possible dual tumor cell population was suggested. However, no cilia were seen in any of the tumor cells and almost all were devoid of secretory granules. These latter observations suggest that this tumor was primarily a proliferation of intercalary cells.

Simultaneous assay of diazepam, chlordiazepoxide, N-desmethyldiazepam, N-desmethylchlordiazepoxide, and demoxepam in serum by high performance liquid chromatography

A method is presented for simultaneously determining diazepam and chlordiazepoxide along with their respective major active serum metabolites N-desmethyldiazepam, and N-desmethylchlordiazepoxide and demoxepam. The drugs are extracted from one ml of buffered serum using chloroform containing 5-(p-methylphenyl)-5-phenylhydantoin as an internal standard. The elution is accomplished using a reversed-phase column with a mobile phase consisting of an acetonitrile/methanol/acetate buffer pH 5.0 (200/225/500) at a flow rate of 2.0 ml/min. Absorbance is monitored at 240 nm using a variable wavelength detector. Each chromatographic separation requires approximately 15 minutes at ambient temperature. Of more than twenty drugs tested for possible interference with this procedure, only methaqualone interferes with the internal standard, and phenytoin with demoxepam.

Comparison of an Enzyme Immunoassay and a High Performance Liquid Chromatographic Method for Quantitation of Quinidine in Serum

AbstractThe need to monitor serum or plasma levels of quinidine in the treatment of cardiac arrhythmia is well documented [1-3] Quinidine has been assayed by fluorometry [4, 5], chromatographic methods [6, 7, 9], and, most recently, an enzyme immunoassay technique (EMIT). We have compared the enzyme immunoassay method with a reverse-phase high performance liquid chromatographic method [7, 9]

The albumin binding of unconjugated bilirubin in serum

1. The limited bilirubin binding capacity of human serum albumin, and the fact that kernicterus can occur once the serum unconjugated bilirubin concentration exceeds this capacity, makes the assessment of non-albumin bound free bilirubin valuable in cases of severe neonatal hyperbilirubinemia. 2. Present methodology for this assessment utilizes Sephadex column chromatography, and is somewhat tedious and slow. 3. We have developed a procedure for assessing the albumin binding capacity of serum by titrating a sample of the serum with T-20 Dextran coated charcoal. 4. The method requires 2 ml of serum, takes 90 minutes to complete and is highly reproducible. 5. By this method, we can determine the reported secondary loose binding capacity of the albumin as well as the tight binding capacity which is determined by existing methods. 6. The tight binding capacity of a pool of normal adult human serum was found to be 20 mg/dl of serum. 7. This is in agreement with existing methods. The loose binding capacity was found to be an additional 10 mg/dl of serum. Added phenobarbital was found to lower the tight binding capacity, but not the secondary capacity.

A procedure for estimating bias between quantitative analytical methods

Before quality control techniques and protocols can be applied to a laboratory procedure, the quality itself must be evaluated. This involves among other considerations an assessment of analytical accuracy. Some, but not all (and perhaps not even many), clinical laboratory analytical procedures can be considered accurate in the sense that every laboratory should get the same quantitative result for the analyte in question, regardless of the composition of the sample medium (for example potassium). That most methods are to one degree or another inaccurate does not invalidate their use. But the burden is on the laboratory, in choosing a method, to knowjust how accurate that method is.

Immune complex deposition in thyroid carcinoma associated with chronic thyroiditis

Abstract A case of unilateral multifocal carcinoma of the thyroid associated with chronic lymphocytic thyroiditis was studied by electron microscopy and by immunofluorescence. Immune complex deposits were demonstrated in the follicular basement membrane (FBM) correlating with positive immunofluorescent staining with anti-IgG, anti-C3, and antithyroglobulin. This report provides evidence that a humoral immune mechanism with immune complex deposition, such as previously described in Hashimotos thyroiditis, may also play a role in the pathogenesis of thyroiditis associated with carcinoma of the thyroid. An attempt is made to explain the selective deposition of immune complexes in the FBM.