Showing papers in "Annals of Clinical and Laboratory Science in 1975"

The ultrastructure of bone.

Abstract: The ultrastructure of the three specialized bone cells are described in relation to their function. Osteoblasts are the bone forming cells with an abundance of RER and a large Golgi area. Osteoblasts and osteocytes form an integrated cell system connected with each other by cell processes filled with actin-like filaments and joined by specialized cell junctions, probably gap junctions. Osteoclasts resorb bone. Characteristics are multiple nuclei, and abundance of mitochondria, a sparcity of RER and clusters of ribosomes. Lysosomes and vesicles contain hydrolytic enzymes. The resorbing area consists of a ruffled border completely encircled by a clear zone.

Parathyroid hormone: radioimmunoassay and clinical interpretation.

Abstract: A radioimmunoassay for serum immunoreactive parathyroid hormone (iPTH), which has had widespread clinical use for five years, is described in detail. The iPTH results in large groups of patients are reported, and are discussed in relation to the specificity of the assay and in relation to other assays. The assay has excellent precision and is highly proficient in discrimination of groups of patients. Ninety-three percent of 412 patients with surgically proven primary hyperparathyroidism were confidently separated from normal subjects or patients with hypercalcemia owing to other causes, while 86 percent of 160 patients with chronic renal failure and secondary hyperparathyroidism had iPTH values more than 2 S.D. above the normal mean. Results in patients with ectopic hyperparathyroidism were lower than in primary hyperparathyroidism although these groups showed considerable overlap. The antiserum used in this assay for iPTH appears to be specific for the carboxy-terminal region of the secreted or intact form of PTH but recognizes predominantly the secreted form rather than carboxy-terminal fragments believed to be in the circulation. It does not recognize amino terminal fragments. The assay is useful in selective venous catheterization for preoperative localization of hyperfunctioning parathyroid tissue.

Ultrastructure of the synovial membrane

Abstract: The normal synovial membrane as seen by electron microscopy is bordered by one to three layers of lining cells that include some with phagocytic function, others rich in endoplasmic reticulum for protein synthesis and additional cells with mixed properties. Lining cells with prominent Golgi apparatus probably produce the synovial hyaluronic acid. The synovial matrix contains collagen and mucopolysaccharide. It offers little barrier to diffusion of most materials. Superficial capillaries and venules are fenestrated and presumably allow rapid exchange of fluid and electrolytes. Deeper venules have thick endothelium that can separate at intracellular junctions and can phagocytize circulating particles. Other identified synovial structures are fibrocytes, macrophages, lymphatics, mast cells, non-myelinated nerves and fat.

Erythropoietin production in renal tumors.

Abstract: A review of the pertinent literature on the relation of erythropoietin production to the presence of renal neoplasm suggests that erythropoietin may be produced either directly by the tumor or indirectly by its physical effect on the adjoining normal renal tissue. The most commonly found tumors which are associated with elevated levels of serum and urinary erythropoietin are the hypernephromas. However, the presence of erythropoietin and an associated erythrocytosis even here occurs only relatively infrequently. Some studies have demonstrated the presence of erythropoietin activity in tumor tissue itself but erythropoietin has not been isolated from renal tumor tissue. In some patients with Wilms' tumor, erythropoietin blood levels may also be increased; however, erythrocytosis in these patients is not a characteristic feature. Other renal tumors rarely produce erythrocytosis and presumably no erythropoietin. Possible explanations for the production of erythropoietin by renal tumors are discussed.

Review of phosphate methodologies.

Abstract: A description of the extensive literature on the methodologies for the determination of serum phosphate has been reviewed. The evolution of the various phases of the analytical techniques developed in the last century leading to the simplified, sensitive and accurate procedures of the present have been presented in some detail. A procedure involving a simple direct reaction for the determination of inorganic phosphate in serum using ascorbic acid as a reducing agent and a citrate-arsenite mixture as a stabilizing-sensitizing reagent, all in a semi-aqueous medium containing dimethysulfoxide and the detergent Teepol 610 is recommended. Jaundice and mild hemolysis are noninterferencts and turbidity from severe lipemia is easily overcome by reversing the sequence in which reagents are added because citrate binds molybdate in preference to phosphate. Thus, the serum blank and the reacted serum are identical in makeup thereby yielding an idealized correction for irrelevant absorption. Reaction characteristics and potential errors are included in the discussion of the procedure.

Rapid microanalysis of cholesterol in bile and serum by gas chromatography.

Abstract: Bile and serum cholesterol concentrations were analyzed by the same saponification, extraction and gas chromatographic procedure, utilizing stigmasterol as an internal standard and trifluoroacetate derivatization. The method was rapid and highly sensitive, requiring only 20 to 50 mul of sample. Comparable levels of precision were achieved by parallel analysis of a series of bile and serum samples by the present method and the Abell colorimetric method; a high degree of correlation was found between these two methods.

Sudden infant death syndrome: plasma vitamin E levels and dietary factors.

Abstract: A retrospective case control study undertaken in San Diego and directed toward the examination of a number of factors previously suggested as etiologically related to the sudden infant death syndrome (SIDS) found that the diet of SIDS infants was less varied and contained lower vitamin supplementation than the diet of the controls and that SIDS in comparison to the controls were more likely to have mothers who smoked during pregnancy. No significant difference was obtained between SIDS infants and controls in regard to plasma vitamin E levels. Surprisingly 39% of the SIDS infants were totally or partially breast-fed compared to 34% of the controls and totally or partially breast-fed infants died earlier than SIDS infants who were bottle-fed. The study was based on blood samples taken from 18 SIDS 17 normal infants and 18 normal neonates and data obtained from questionnaires returned by 46 SIDS parents 48 parents of matched controls and 39 parents of randomly selected infants at a pediatric clinic. Tables included 1) vitamin E levels for SIDS infants and controls and 2) dietary variables with significance levels. Also included is a graph showing the % breast-fed by age for controls and SIDS and a scatter diagram of plasma vitamin E levels plotted against age for both SIDS infants and controls.

The measurement of erythropoietin.

Abstract: The bioassay of erythropoietin in animals is reviewed. The techniques employed are those of hypertransfusion and hypoxia using polycythemic mice.

Multiple sclerosis: immunologic aspects.

Abstract: Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS). Although the causes are not known, the pathogenesis likely involves complex relationships between autoimmunity, immunogenetics, immunologic deficiency and viral infection. The evidence for such interrelationships is discussed.

Ultrastructure of the nervous system

Abstract: Within the nervous system, five cell types were studied by the electron microscope: the neuron, astrocyte, oligodendroglia, microglia and ependymal cells. The neurons are characterized by the Nissl substance within the perikaryon, the neurotubules and the neurofilaments. The three types of glial cells can be distinguished from one another. The astrocyte has relatively lucent cytoplasm and contains filaments which extend into long cytoplasmic processes. The oligodendroglia has electron-dense cytoplasm with thin extensions wedged between the cellular processes of the neuropil. The microglia cytoplasm is similar to the oligodendroglia but can be differentiated by the peculiar convoluted outline of the nuclear membrane and the clear space which separate the nucleus from the cytoplasm. The ependymal cell has characteristic microvilli and cilia at its ventricular surface. The cytoplasm contain parabasal bodies and tight junctions between adjacent cells. In the peripheral nerve, the axon and the myelin sheath are located within the Schwann cells. The terminal nerve endings from enlargements filled with synaptic vesicles. Electron microscopy of the nervous system is not only essential for research, but is also helpful in diagnosis of certain diseases.

Tumors of striated muscle

Abstract: Three benign forms of muscle tumors and three variants of rhabdomyosarcoma are discussed from the point of view of their histology and behabior. Recent combined modality therapy has significantly improved the prognosis in at least the embryonal form of rhabdomyosarcoma.

Review of calcium methodologies.

Abstract: A review of calcium methodologies for serum has been described. The analytical systems developed over the past century have been classified as to type beginning with gravimetry and extending to isotope dilution-mass spectrometry by covering all of the commonly used technics which have evolved during that period. Screening and referee procedures are discussed along with comparative sensitivities encountered between atomic absorption spectrophotometry and molecular absorption spectrophotometry. A procedure involving a simple direct reaction for serum calcium using cresolphthalein complexone is recommended in which high blanks are minimized by repressing the ionization of the color reagent on lowering the dielectric constant characteristics of the mixture with dimethylsulfoxide. Reaction characteristics, errors which can be encountered, normal ranges and an interpretative resume are included in its discussion.

Current status of zinc deficiency in the pathogenesis of neurological, dermatological and musculoskeletal disorders.

Abstract: Recent clinical and experimental studies suggest that zinc deficiency may play an important role in the pathogenesis of (1) acrodermatitis enteropathica, and in certain cases of (2) hypogonadal dwarfism, (3) congenital malformations, (4) hypogeusia and hyposmia, (5) nyctalopia and (6) impaired wound healing. Distrubances of zinc metabolism also occur in a broad spectrum of other clinical disorders. The pathophysiological factors which are responsible for hypozincemia include: (1) nutritional deficiency and/or intestinal malabsorption of zinc; (2) hyperzincuria secondary to aminoaciduria; (3) hormonal effects (cortisol, growth hormone, estrogens); (4) hypoalbuminemia; and (5) effects of leukocytic endogenous mediator. The clinical diagnosis of zinc deficiency in patients with specific neurological, dermatological and musculoskeletal disorders is complicated by the complex interactions of these pathophysiological factors and by the need for more dependable laboratory indices of zinc deprivation.

Growth disorders and homocysteine metabolism.

Abstract: Inherited disorders of homocysteine metabolism produce accelerated growth and arteriosclerosis with myointimal hyperplasia. The growth of cell cultures from cystathionine synthetase deficient individuals with homocystinuria is characterized by abnormal contact inhibition and production of an aggregated proteoglycan matrix which binds excess sulfate. Homocysteic acid, a precursor of sulfate ester, increases the growth rate of normal guinea pigs. Synthesis of homocysteic acid from homocysteine thiolactone is more rapid in the livers of young animals than adults, and hypophysectomy results in a pattern of homocysteine thiolactone metabolism resembling that in liver of adult animals. Homocysteine thiolactone metabolism differs in guinea pig, an herbivorous species, and in rat, an omnivorous species. Sulfate binding by cultured human cells is slightly increased when homocysteic acid is present in the culture medium. These observations suggest a relationship between homocysteic acid and somatomedin, a serum polypeptide which mediates the action of growth hormone. The growth disorders associated with homocystinuria, including arteriosclerosis and accelerated growth, are believed to result from increased conversion of methionine to homocysteine thiolactone and homocysteic acid.

Current concepts of the formation and composition of amyloid

Abstract: Immunochemical and chemical studies of purified amyloid fibril protein from a wide variety of human tissues reveals that amyloid fibrils may derive from immunoglobulin proteins most frequently in the "primary" disease and can be classified as of kappa- or lambda-type. In addition a protein of unknown origin is the source of amyloid fibrils in another group of cases usually of "secondary" type. The creation of fibrils with all the characteristics of amyloid fibrils has been accomplished by proteolysis of some Bence Jones proteins. This indicates that amyloid fibrils may be formed by proteolytic digestion of circulating light polypeptide chains of immunoglobulin proteins.

Testicular changes associated with the initiation of spermatogenesis.

Abstract: Testicular changes preceding and accompanying the initiation of spermatogenesis are reviewed. The complex cellular changes occurring in the developing testis are found to be particularly well defined with the use of electron microscopy. The findings suggest that electron microscopic examination may be useful in the evaluation of male infertility, especially in those cases in which clinical and laboratory findings are negative or inconclusive. The amount of tissue required is minimal and can be taken as part of the regular testicular biopsy. The additional information provided by electron microscopy can be used to clarify the observations made on routine light microscopic study and may also lead to better understanding of the pathologic changes occurring in some of the less well understood forms of male infertility.

Serum and urine polyamines in cancer.

Abstract: Polyamines in serum and urine have been found to be elevated in patients with cancer. A variety of methods employed for these measurements are discussed. Normal values obtained by the most recent methods are presented, and a survey has been made of polyamine levels in cancer patients.

Somatomedin and the regulation of skeletal growth.

Abstract: Somatomedin is a polypeptide(s) which "mediates" the actions of growth hormone. This pituitary dependent hormone was previously called "sulfation factor," a term derived from the bioassay technique which measures the incorporation of radioactive sulfate into cartilage glycosaminoglycans. Somatomedin has a more general effect upon cartilage; it is necessary for the cell multiplication and cartilage maturation which results in the growth of long bones. Somatomedin is not found in the plasma in growth hormone deficiency and appears following growth hormone administration. A genetic defect in somatomedin synthesis has been identified in the Laron's dwarf. Growth hormone is present in excess in the plasma and growth hormone administration does not stimulate somatomedin synthesis in this syndrome. Insufficient data are available to delineate the role for somatomedin in other growth disturbances. It has been demonstrated that glucocorticoid hormones interfere with both somatomedin synthesis and its biological activity. Purification of somatomedins in plasma has been achieved and radioreceptor or radioimmunoassays will be available in the future for study of growth problems in children.

Metabolic and biochemical considerations of bone

Abstract: Recognition of the dynamic aspects of bone metabolism can lead to a unified concept involving endocrine and nutritional influences. Although most hormones can influence bone metabolism directly or indirectly, the principal ones involved in skeletal metabolism are parathyroid hormone, calcitonin and 1,25-dihydroxy-vitamin D. The actions of parathyroid hormone and 1,25-dihydroxy-vitamin D result in elevations of circulating extracellular fluid calcium concentration through actions directly on bone, intestine, and kidney. Calcitonin leads to decreases in calcium concentration, primarily by action on bone and kidney. The absorption and retention of calcium by the organism is further influenced by the dietary content of calcium, phosphorus, protein, and fluoride. Chronic dietary deficiencies of calcium and excesses of phosphorus may lead to chronic nutritional secondary hyperparathyroidism with resulting skeletal demineralization. In both experimental animals and in man, the earliest manifestation of this condition may be demineralization of the jaw with resultant paradentosis. Experimental studies in animals and in man have shown that this form of demineralization may be completely reversed by increasing dietary calcium and decreasing dietary phosphrous.

Diagnostic value of cytologic specimens obtained from children with cancer.

Abstract: The practical value of cytologic examination in the clinical management of children with cancer was determined by analyzing 2,363 cytologic specimens collected during a two year period. The specimens included cerebrospinal fluid, pleural and peritoneal effusions, urine and tracheal aspirates from 347 children with cancer. Malignant tumor cells were detected in 266 specimens obtained from 106 children with the following malignant neoplasms: leukemia 44/133, ma­ lignant lymphoma 13/64, soft tissue sarcoma 13/48, neuroblastoma 13/26, Wilms’ tumor 4/18, malignant teratoma 4/13, osteogenic sarcoma 7/11, Ewing’s sarcoma 2/10, brain tumor 5/6 and retinoblastoma 1/1. No malignant cells were detected in fluids from 18 patients with other tumors. The malignant cells were identified most often in spinal fluid, pleural and peritoneal effusions. Cytologic examination appears to be of value in the clinical management of children with cancer.

Etiology of hyperuricemia

Abstract: Hyperuricemia is a common laboratory finding with significant clinical implications. It is easily detected, but its mechanisms may not be clearly elucidated. A scheme of pathogenesis has been outlined and diagrammed but much is conjectural; therefore, the classification is merely tentative. About 45 diseases or categories of conditions, 20 drugs, and nine states of intoxication have been surveyed. Hyperuricemia can be a multifactorial genetic disorder or a discrete response to a specific stimulus. It may be governed by a complex interplay of biochemical disorders for a lifetime duration, or it may be determined by environmental forces for a very transient course. Some conditions have both increased production of uric acid as well as decreased renal outflow. For many patients, the underlying mechanisms have not yet been elucidated.

Electrothermal atomic absorption spectrometry of trace metals in biological fluids.

Abstract: Electrothermal atomic absorption spectrometry has five major advantages for measurements of trace metals in biological materials, in comparison to measurements by conventional flame atomic absorption analysis: (1) Trace metal contamination is minimized by avoidance of preliminary chemical extractions and additions of reagents; (2) Sample volumes are small (1 to 50 mu1). The entire sample is vaporized in electrothermal atomization, whereas in most flame nebulization systems only a small fraction of the sample enters the flame; (3) Atoms are released in higher concentrations. In electrothermal atomization, the atom cloud is released into a relatively small volume of gas. In contrast, in flame atomization, the atom cloud is diluted by the high flow rate of gases and by expansion of gases during combustion; (4) Molecular recombination of atoms is retarded by the atmosphere of inert gas which restricts chemical reactions (e.g., oxidation). In contrast, in flame atomization, oxidation occurs very rapidly; and (5) By programmed increments in temperature, electrothermal atomization permits organic constituents to be pyrolyzed prior to vaporization and atomization of metals. Despite these advantages, electrothermal atomic absorption is particularly subject to interferences and sources of imprecision which necessitate critical evaluations in the prospective analyst's laboratory before an electrothermal method can be confidently employed for diagnostic measurements of a specific trace metal in body fluids.

The biochemistry of collagen

Abstract: Collagen synthesis and subsequent extracellular stabilization and turnover are multi-step processes. The sequence of events in these processes is reviewed and correlated with collagen pathologies.

Amyotrophic lateral sclerosis. Inclusion bodies in a case of the classic sporadic form.

Abstract: Postmortem light and electron microscopic studies of a 52 year old black male who died 17 months after the onset of upper and lower motor neuron signs showed: (1) degeneration of cortico-spinal tracts, (2) loss of spinal neurons and gliosis and (3) cellular inclusions with neurotubules, neurofilaments and granular material. Although these cellular inclusions resemble Lafora bodies, they differ in that, to the authors' knowledge, the latter were not reported to have microtubules. Review of the literature revealed no previous report of these inclusions in cases of amyotrophic lateral sclerosis. Tissue cultures of cord, hindbrain and cerebrum did not show cytopathic effect during a three-week observation period.

Non-myogenic tumors involving skeletal muscle. A survey with special reference to alveolar soft part sarcoma.

Abstract: Skeletal muscle is remarkably free of neoplasms despite its great body mass. Metastatic tumors to skeletal muscle are distinctly uncommon. Primary myogenous tumors (defined as those whose cytoplasm contains myofibrils) are infrequent, compared to primary lesions of supporting stroma and vascular origin. Almost all non-myogenic tumors of striated muscle occur also in other areas of the body and many represent extension from contiguous structures. The distinctive non-myogenic tumor which occurs exclusively in skeletal muscle, alveolar soft part sarcoma, has ultrastrucutral features of a secretory lesion with distinctive membrane bound crystalloids which may be lipid in nature. The ultrastructural features of alveolar soft part sarcoma do not support a myogenous derivation.

Electron microscopy of disorders of skeletal muscle

Abstract: Some of the common pathologic changes in the muscle fiber as viewed with the electron microscope are considered. These include myofilament and Z band abnormalities, alterations of the sarcotubular system, mitochondrial aberrations and glycogen accumulations. Correlations with light microscopic findings are mentioned when pertinent. The diagnostic significance of the various ultrastructural changes is discussed.

Modified method for analysis of serum iron.

Abstract: An improved method for analysis of serum iron is described which is simple, rapid, precise and convenient for routine use in clinical laboratories. Serum proteins are precipitated with trichloroacetic acid-hydrochloric acid solution, with simultaneous release of Fe(III) from transferrin. Fe(III) is reduced to Fe(II) by sodium ascorbate, and Fe(II) is reacted with ferrozine to form a lavender complex, which is measured by spectrophotometry at 562 nm. Measurements of iron in 183 serum samples by this method were compared with measurements by a "direct" spectrophotometric method without without deproteinization, as previously described. Close agreement was obtained in 171 of these 183 pairs of analyses (93.5 percent). Discrepancies (greater than 12 mug per dl) were noted in the remaining 12 serums, which were attributed to interference in direct spectrophotometric analyses of iron, owing to (1) hemolysis, (2) lipemia, (3) jaundice, (4) protracted storage or (5) repeated freezing and thawing of the serums.

Developments in laboratory diagnosis of chromosomal abnormalities

Abstract: The development of chromosome banding techniques has made possible the detailed analysis of human chromosomes. A vast body of knowledge has accumulated during the last few years as a result of their application in biology and medicine.

Mechanism of action of neurotoxins

Abstract: This paper is a summary of studies over the past few years that pertain to animal neurotoxins. These toxins are found throughout the animal kingdom. Homologies exist in the structures of these poisons within classes and point to conservation of active sites throughout evolution. In the case of the peptides, invariant amino acids may be involved in the active site, be essential for maintaining the shape and conformation of the molecule or serve as a fulcrum for folding of the peptide chain after synthesis. At the nuclear or DNA-level, a constant base sequence may regulate gene operation so that only a specific amino acid is coded. Physiologically, and with ultrastructural and biochemical correlation, the predominant mode of action of neurotoxins relate to one or the other of the major activities of the excitable cell,--on conductile activity affecting Na+ or K+ permeabilities, on output or secretory activities affecting the release of neurotransmitter or on in put generator activities affecting the receptor molecules for transmitter themselves. The future of these animal neurotoxins in neurobiological research is secure. The elucidation of molecular mechanisms, by which these various physiological activities of excitable tissue are expressed, will surely involve one or more of these fascinating, naturally-occurring compounds.

Automated bichromatic analysis of serum ceruloplasmin.

Abstract: An automated micromethod is described for measurement of serum ceruloplasmin by assay of its p-phenylenediamine oxidase activity using the Abbott bichoromatic analyzer. Ten mul of serum are mixed with 250 mul of p-phenylenediamine (PPD) substrate (9.2 mmole per liter) in acetate buffer (0.1 mole per liter, pH 5.45). Spectrophotometric measurements of the rate of formation of the purple oxidation porduct of PPD are performed after a 10 min delay for thermal equilibration at 37 degrees and for avoidance of the lag-phase of the enzymatic reaction. The coefficients of variation of replicate analyses of normal serum by this technique are 1.1 percent (within-the-run) and 3.3 percent (day-to-day). Measurements of ceruloplasmin concentrations in serums from 75 patients by this automated method provided close correlation with measurements by a manual reference procedure (correlation coefficient=0.973). The mean concentration of ceruloplasmin in serums from 64 healthy men was 29 mg per dl (central 95th percentile limits=22 to 40 mg per dl).