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1.
Suicide Life Threat Behav ; 22(2): 197-225, 1992.
Article in English | MEDLINE | ID: mdl-1626333

ABSTRACT

Durkheim's influential book, Suicide, provides general (economic) anomie, conjugal anomie, and sex-role convergence explanations of changes in suicide rates under conditions of social change. We used trend analyses of American suicide rates and female/male suicide ratios from 1950 to 1984 and the regression of the ratios on female educational attainment, white female labor force participation, white fertility rates, and divorce rates to examine these explanations. The general anomie explanation of female suicide trends is supported for the middle-aged (30 to 54 years) but not for the young (10 to 30 years) or the elderly (55 to 74 years). The conjugal anomie proposition is at best supported for age groups between 15 and 44 when general anomie is not pronounced. The role convergence explanation is rejected for all 13 5-year-age-groups. General anomie may not be a viable explanation of suicide trends for groups actively supporting relevant social changes or not yet tradition-bound or for groups whose retirement status reduces the importance of some social changes.


Subject(s)
Anomie , Gender Identity , Suicide/psychology , Women's Rights , Adult , Aged , Cross-Sectional Studies , Female , Humans , Incidence , Middle Aged , Social Environment , Suicide/trends , United States/epidemiology , Women's Rights/trends
2.
Int Anesthesiol Clin ; 29(2): 25-36, 1991.
Article in English | MEDLINE | ID: mdl-2071221

ABSTRACT

In conclusion, anesthesia and mechanical ventilation have major effects on respiratory function, both intraoperatively and postoperatively. Recognition that mechanical ventilation represents a major departure from spontaneous ventilation should enable anesthesiologists to compensate for the increases in dead space ventilation and the propensity for alveolar collapse that accompany low volume mechanical ventilation. The use of postoperative regional analgesic techniques to alleviate respiratory compromise constitutes both current clinical practice and an area of active, ongoing investigation. Gone are the days when the anesthesiologist's responsibility stopped at the recovery room door. Today, anesthesiologists with expertise in postoperative pain management, cardiovascular physiology, and intensive ventilatory care are able to provide patients an improved likelihood of avoiding postoperative respiratory complications.


Subject(s)
Anesthesia Recovery Period , Postoperative Complications/etiology , Respiration Disorders/etiology , Humans
3.
Am J Anat ; 181(2): 149-62, 1988 Feb.
Article in English | MEDLINE | ID: mdl-3369357

ABSTRACT

The feline species provides animal models for at least six congenital lysosomal disorders. Since knowledge of normal feline neutrophils is a prerequisite for studies of their abnormalities, the present report describes the morphology and cytochemistry of normal feline neutrophils and compares the subcellular distribution of sulfate- and vicinal-glycol-containing complex carbohydrates to that of peroxidase and acid phosphatase. Immature feline primary granules, formed in promyelocytes, were stained for peroxidase, acid phosphatase, sulfate, and vicinal glycols. During maturation, primary granules retained strong staining for peroxidase, but staining for vicinal glycols decreased, and acid phosphatase and sulfate reactivity was lost. Secondary granules formed in myelocytes lacked peroxidase, acid phosphatase, and sulfate staining, but stained intensely for vicinal-glycol-containing complex carbohydrates. No analogues of tertiary granules previously described in rabbits and humans were demonstrated in feline neutrophils. However, a new sequential staining technique for peroxidase and vicinal glycols has suggested the formation in myelocytes and late neutrophils of a third granule type that contained peroxidase, acid phosphatase, and vicinal glycols but lacked sulfate staining. Thus, the staining characteristics of primary and secondary granules in cats closely resembled those in humans and rabbits. The third (late-forming) type of granule has not previously been described in other species.


Subject(s)
Neutrophils/ultrastructure , Acid Phosphatase/analysis , Animals , Cats , Cytoplasmic Granules/ultrastructure , Glycoconjugates/analysis , Histocytochemistry , Neutrophils/metabolism , Peroxidases/analysis , Sulfates/analysis
4.
Cell Tissue Res ; 251(1): 23-30, 1988 Jan.
Article in English | MEDLINE | ID: mdl-3277715

ABSTRACT

Previous immunohistochemical data have shown that the 44-kDal bone phosphoprotein (44K BPP, also called sialoprotein I or oestopontin) recently isolated in our laboratory was synthesized by osteoblasts and osteocytes and was expressed early during differentiation of bone-forming cells. We report here the presence of 44K BPP antigenicity at certain ectopic sites, namely, the proximal-convoluted tubule of the kidney, neurons, sensory and secretory cells in the internal ear. To insure specificity and reproducibility, different immunohistochemical methods were used and affinity-purified antibodies against two separate preparations of pure 44K BPP were tested. In the cells of the proximal-convoluted tubule, 44K BPP immunoreactivity was observed within apical endocytotic vacuoles and within lysosomes. This staining thus correlates with the degradation of the 44K BPP epitope which we previously demonstrated to occur in serum. On the other hand, in the neurons of the acoustic ganglion and the sensory cells of the macula, 44K BPP immunoreactivity was associated with the Golgi apparatus indicating synthesis and secretion by these cells. The finding that the 44K BPP (or a structurally related molecule) is synthesized by neurons and neuroepithelial cells deserves further investigation with respect to a possible embryologic relationship between neuroectodermal cells and the precursors of some bone forming-cells of the skull.


Subject(s)
Ear, Inner/analysis , Kidney/analysis , Nervous System/analysis , Phosphoproteins/analysis , Sialoglycoproteins/analysis , Animals , Animals, Newborn , Bone and Bones , Brain Chemistry , Ear, Inner/cytology , Fluorescent Antibody Technique , Immunoenzyme Techniques , Kidney/cytology , Microscopy, Electron , Nervous System/cytology , Neurons/analysis , Osteopontin , Rats , Rats, Inbred Strains , Trigeminal Nerve/analysis
5.
Clin Chem ; 33(11 Suppl): 101B-105B, 1987 Oct.
Article in English | MEDLINE | ID: mdl-3677407

ABSTRACT

The substance abuser brings his problems to the workplace. Ninety-five percent or more of all individuals experiencing alcohol-or drug-related problems are either employed or the spouse or dependent of someone who is working. It is clear we are facing a problem which transcends the boundaries of the workplace. The result in the workplace, of course, is increased costs, lower productivity, more accidents on the job, but most importantly additional suffering for the individuals involved. It is important to remember that neither GM, the UAW, nor the IUE can be expected to accept responsibility for those individuals who have the ability to control their own "wellness" and productivity. Any joint union-management substance abuse program can only be a catalyst to help individuals confront their problems. Along with the other groups and institutions concerned with these problems, GM, in cooperation with the UAW, IUE, and the other unions that represent our employees, is trying to help individuals with addictive diseases confront and obtain treatment for their problems. We believe our programs are moving in the right direction and will continue to make progress.


Subject(s)
Industry , Occupational Health Services , Personnel Management , Substance-Related Disorders/therapy , Alcoholism/therapy , Employee Discipline , Humans
6.
J Bone Miner Res ; 2(4): 337-46, 1987 Aug.
Article in English | MEDLINE | ID: mdl-3502680

ABSTRACT

Bone gamma-carboxyglutamic acid (Gla)-containing protein (BGP or osteocalcin) and 44 kDa bone phosphoprotein (44K BPP, also called Sialoprotein I or osteopontin) have been localized at the ultrastructural level in osteoblasts from woven bones of newborn rats. Frozen, undecalcified sections of periodate-lysine-paraformaldehyde fixed specimens were incubated with affinity purified, monospecific antibodies against BGP or 44K BPP. The sites of the antigen-antibody reaction were demonstrated by the avidin-biotin-peroxidase complex method using the Hanker-Yates reagent as a peroxidase substrate. In some cases immunostaining could only be achieved after detergent treatment. The immunostained sections were then flat-embedded in Epon 812 and processed for electron microscopy. Strong specific intracellular labeling was obtained with both antibodies, but the patterns of staining differed significantly: BGP antigenicity was mainly located in the endoplasmic reticulum (ER), whereas 44K BPP behaved as a Golgi-specific antigen. In both cases, however, we found no evidence for immunostained secretory vesicles. There was no correlation between the expression of BGP by osteoblasts and the morphological aspect of these cells, their apparent degree of polarization with respect to the bone matrix, or their relation with the mineralized phase.


Subject(s)
Calcium-Binding Proteins/analysis , Mandible/analysis , Osteoblasts/analysis , Sialoglycoproteins/analysis , Animals , Endoplasmic Reticulum/analysis , Endoplasmic Reticulum/ultrastructure , Golgi Apparatus/analysis , Golgi Apparatus/ultrastructure , Immunohistochemistry , Mandible/ultrastructure , Microscopy, Electron , Molecular Weight , Osteoblasts/ultrastructure , Osteocalcin , Osteopontin , Phosphoproteins/analysis , Rats
7.
Anat Rec ; 205(3): 301-11, 1983 Mar.
Article in English | MEDLINE | ID: mdl-6188387

ABSTRACT

Neutrophil secondary granules contain large amounts of glycoprotein. We evaluated periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining of these granules after alpha-amylase digestion to assess their content of vicinal glycol-containing glycoconjugates and the usefulness of this stain as a positive stain for secondary granules. Using this method, early stages of secondary granule genesis were observed prior to completion of primary granule genesis in myelocytes. Immature secondary granules appeared round to ovoid, but irregular in outline and demonstrated strong staining of the limiting membrane and matrix material. In mature granules, matrix staining was unaltered; however, membrane staining was decreased. Some immature primary granules in promyelocytes demonstrated strong PA-TCH-SP reactivity which was masked in mature primary granules of band and segmented neutrophils. The Golgi apparatus showed progressively increasing PA-TCH-SP reactivity toward its mature surface which was often convex in promyelocytes and myelocytes and concave in segmented neutrophils. The Chédiak-Higashi secondary granules were cytochemically and morphologically similar to those of normal individuals and were not statistically decreased in number when compared to controls. They were only rarely observed contacting or fusing with giant granules which had consumed all primary granules leaving an easily detected population of secondary granules. Thus the alpha-amylase-PA-TCH-SP method demonstrates a large amount of unmasked vicinal glycol-containing glycoconjugates in neutrophil secondary granules, which allows their differentiation from primary granules.


Subject(s)
Chediak-Higashi Syndrome/pathology , Cytoplasmic Granules/ultrastructure , Glycols , Neutrophils/ultrastructure , Bone Marrow/ultrastructure , Bone Marrow Cells , Humans , Staining and Labeling
8.
Blood ; 61(2): 257-66, 1983 Feb.
Article in English | MEDLINE | ID: mdl-6401432

ABSTRACT

Chondroitin sulfate is known to be present in normal and leukemic myeloid cells; however, its definitive subcellular location and association with other glycosaminoglycans (GAGs) has not been demonstrated. We have studied the type and distribution of GAGs in neutrophil granule subpopulations of normal and leukemic myeloid cells using ultrastructural, cytochemical, immunologic, and biochemical methods. At the ultrastructural level, high-iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP) stained sulfated glycoconjugates selectively in immature primary granules of normal promyelocytes and Auer rods and immature granules of leukemic myeloblasts. Staining was weak or absent in mature primary granules, whereas tertiary granules stained moderately. Primary granule staining with HID-TCH-SP was greatly diminished by prior treatment of the specimens with chondroitinase ABC and/or nitrous acid, indicating the presence of chondroitin sulfate and N-sulfated glycosaminoglycan. Immunostaining of myeloid cells with a rabbit antichondroitin 4-sulfate and ferritin-conjugated goat anti-rabbit IgG sequence resulted in staining of most primary granules. Biochemical analysis of GAGs from leukemic myeloblasts containing primary granules and Auer rods, but lacking secondary and tertiary granules, revealed 8 x 10(-17) mole of uronic acid/cell and electrophoretic and sulfaminohexose analysis showed 60%-70% chondroitin sulfate AC of heterogeneous molecular weight, 20%-30% of a GAG that most closely resembled heparan sulfate, and 10% dermatan sulfate. The lack of significant HID-TCH-SP staining of sulfate iin sites other than Auer rods and primary granules in leukemic myeloblasts indicates that these granules contain the chondroitin, dermatan, and heparan sulfate isolated from the same specimen. Similar GAGs are present in primary granules of normal cells as evidenced by their cytochemical and immunostaining properties. Thus, these studies demonstrate a heterogeneous population of GAGs not previously identified and localize these substances to the primary granule of leukemic and normal cells.


Subject(s)
Glycosaminoglycans/blood , Leukemia/blood , Neutrophils/analysis , Acid Phosphatase/blood , Chondroitin Lyases/metabolism , Chondroitin Sulfates/immunology , Cytoplasmic Granules/analysis , Hexosamines/blood , Histocytochemistry , Humans , Hyaluronoglucosaminidase/metabolism , Immune Sera
9.
Am J Hematol ; 13(4): 303-11, 1982 Dec.
Article in English | MEDLINE | ID: mdl-7158625

ABSTRACT

Neutrophil engulfment by megakaryocytes was observed within 20 to 30% of megakaryocytes from two children: one with metastatic rhabdomyosarcoma, the other with fever of unknown origin. Other cell types and neutrophil precursors were not observed within megakaryocytes. Only late megakaryocytes were involved in the process, and often these cells appeared vacuolated or degenerating at the light and electron microscope level. Ultrastructurally the engulfed neutrophils were intact and were within the open canalicular system of the megakaryocyte cytoplasm. No evidence of neutrophil granule exocytosis could be demonstrated in ultrastructural morphologic and peroxidase preparations; however, many neutrophils appeared to be endocytosing portions of the megakaryocyte cytoplasm. The phenomenon could not be transferred to normal marrow incubated with patient serum or plasma. Thus, our patients differ from previous observations of emperipolesis in: 1) the extreme frequency of the observation; 2) the selective involvement of neutrophils; and 3) the association of the anomaly with dysmorphic and/or disrupted megakaryocytes. These observations are consistent with a neutrophil response to altered and/or injured megakaryocytes.


Subject(s)
Megakaryocytes/ultrastructure , Neutrophils/ultrastructure , Phagocytosis , Bone Marrow/ultrastructure , Child , Female , Fever of Unknown Origin/blood , Humans , Microscopy, Electron , Neoplasm Metastasis , Rhabdomyosarcoma/blood
10.
Am J Pathol ; 109(3): 343-58, 1982 Dec.
Article in English | MEDLINE | ID: mdl-7180945

ABSTRACT

Lactoferrin in marrow and blood granulocytes from rabbits and humans was stained with an immunoferritin method. Iron-binding protein(s) was localized by the staining of granulocytes with acid ferrocyanide after saturation of the iron-binding protein with iron. The latter was most readily accomplished by treatment of the glutaraldehyde-fixed cell suspension with 1% saponin, followed by treatment with an iron-nitrilotriacetate (Fe-NTA 3mM:4mM) solution, adjusted to pH 7.0 with NaHCO3. The affinity of purified lactoferrin and transferrin for radioiron after such treatment was minimally diminished. Both immunoferritin and iron-binding methods heavily stained osmiophiliuc (phospholipid-containing) mature primary granules in late promyelocytes, myelocytes, and polymorphonuclear cells. Early promyelocytes containing abundant immature primary granules lacked immunoferritin or iron staining. Trypsin digestion of rabbit marrow cells considerably diminished the cytochemically demonstrable iron-binding capability of the mature primary granules. Specimens sequentially stained for peroxidase and immunostained for lactoferrin or cytochemically stained for iron-binding protein confirmed that lactoferrin and iron-binding protein were in peroxidase-positive primary granules. Some peroxidase positive granules appeared to lack staining for lactoferrin and iron-binding proteining protein, and all secondary granules uniformly lacked staining. Treatment of human neutrophils with phorbol myristate acetate demonstrated early release of granules containing iron-binding protein with subsequent agglutination of neutrophils and attachment of iron-binding protein to the cell surface. In summary, this study distinguishes at least two subpopulations of primary granules and identifies lactoferrin and an iron-binding protein(s) in a subpopulation of peroxidase-positive primary granules in rabbit heterophils and human neutrophils.


Subject(s)
Carrier Proteins/metabolism , Granulocytes/ultrastructure , Iron/metabolism , Lactoferrin/metabolism , Lactoglobulins/metabolism , Neutrophils/ultrastructure , Animals , Histocytochemistry/methods , Humans , Rabbits
12.
Blood ; 58(6): 1134-40, 1981 Dec.
Article in English | MEDLINE | ID: mdl-7306702

ABSTRACT

Ultrastructural evaluation of eosinophilic leukocytes from a 2-yr-old asymptomatic girl with chronic benign neutropenia (CBN) revealed a variety of morphological abnormalities. All eosinophils obtained from blood and marrow specimens contained multipole microcrystalloids in most of the mature cytoplasmic granules. An increase in crystalloid-free, immature granules in late (bilobed nuclei) eosinophils suggested a delay in granule maturation. The eosinophil granules appeared to be of normal size and demonstrated normal acid phosphatase reactivity. Eosinophilic myelocytes contained abnormal cisternae of rough endoplasmic reticulum (RER) and lacked abundant elongated RER cisternae seen in normal cells. A few eosinophilic myelocytes in specimens of bone marrow from the child contained large intranuclear crystalloids measuring up to 3 mu in length. The intranuclear crystalloid contained as cubic lattice of dense material with a periodicity similar to that described for cytoplasmic crystalloids. The ultrastructural morphology of marrow neutrophils was normal, as described in other cases of CBN. Ultrastructural examination of blood eosinophils from the father demonstrated microcrystalloids in cytoplasmic granules identical to those seen in the child. The father was asymptomatic and had normal leukocyte counts. Thus, anomalous crystalloid granule genesis occurred in the father and daughter and was not necessarily associated with neutropenia or clinical symptomatology. This anomaly is associated with the accumulation of intranuclear crystalloid material in eosinophilic myelocytes, which do not appear to be released from the marrow compartment.


Subject(s)
Cell Nucleus/metabolism , Cytoplasmic Granules/pathology , Eosinophils/pathology , Organometallic Compounds , Plasma Substitutes/metabolism , Acid Phosphatase/metabolism , Bone Marrow Cells , Child, Preschool , Crystalloid Solutions , Eosinophils/ultrastructure , Female , Humans , Isotonic Solutions , Uranium/pharmacology
13.
Am J Hematol ; 10(4): 341-58, 1981 Jun.
Article in English | MEDLINE | ID: mdl-6787916

ABSTRACT

Platelet-leukocyte interaction was observed in an asymptomatic woman. After incubation in the patient's EDTA-plasma, autologous and allogeneic platelets adhered to the surfaces of neutrophils, monocytes, macrophages and, rarely, eosinophils. Monocytes, macrophages, and occasionally neutrophils phagocytosed platelets. Degranulation of peroxidase-positive lysosomes into the platelet-containing phagosome was demonstrated ultrastructurally. Bone marrow studies indicated that bands and earlier neutrophilic precursors did not participate in the reaction, and that neutrophils adhered to, and were rarely engulfed by megakaryocytes. Sequential exposure of the patient's EDTA-plasma to platelets and leukocytes indicated that a nondialyzable factor(s) was first absorbed by platelets which then interacted with leukocytes. The reaction proceeded best in the presence of EDTA at 21 degrees C, and was inhibited or dissociated by divalent cations or at 37 degrees C. Metabolic integrity of both platelets and leukocytes was also essential for the reaction since each was inhibited by formalin fixation and partially inhibited by the metabolic inhibitor 2-deoxyglucose. Formalin-treated platelets continued to absorb the plasma factor(s). The plasma and the cell fractions were inactivated by periodate and nonspecific protease. Treatment of the platelets with trypsin or the leukocytes with neuraminidase diminished the interaction by 50%. The reaction was also interfered with by concanavalin A. Immunofluorescent and immunoabsorption studies failed to identify an immune component of this interaction. These findings indicate that the plasma factor(s) and the cell surface receptors are nonimmune glycoconjugates and consequently differ from previously documented cases of platelet-leukocyte interaction.


Subject(s)
Blood Platelets , Cell Communication , Leukocytes , Megakaryocytes , Absorption , Adult , Blood Platelets/immunology , Blood Platelets/ultrastructure , Cations, Divalent , Cell Adhesion , Dithiothreitol/pharmacology , Edetic Acid/pharmacology , Female , Humans , Leukocytes/immunology , Megakaryocytes/ultrastructure , Neuraminidase/pharmacology , Streptokinase/pharmacology , Temperature , Trypsin/pharmacology
15.
J Histochem Cytochem ; 28(10): 1067-80, 1980 Oct.
Article in English | MEDLINE | ID: mdl-7419899

ABSTRACT

The subcellular route of incorporation of complex carbohydrates into rabbit heterophil primary granules and their subsequent intragranular distribution during granule maturation were studied with ultrastructural, cytochemical, and radioautographic methods. High iron diamine (HID) staining of sulfated glycoconjugates in primary granules was partially diminished after treatment with chondroitinase ABC or after removal of N-sulfate groups with nitrous acid, but was not altered by exposure to hyaluronidase, trypsin, or HCl. Subsequent thiocarbohydrazide-silver proteinate (TCH-SP) straining of thin sections increased the density of the HID reaction product. Golgi-derived spherules and very immature morular granules stained weakly with HID-TCH-SP and labeled intensely after a 10 min incubation with 35SO4. After a 60 min 35SO4 pulse and a 60 min chase, an increase in radiolabeling was observed in granules with HID stained, fused morular material, and some labeling was present in more mature rim stained granules. Fully mature granules lacked HID or HID-TCH-SP staining, but contained most of the 35SO4 labels after a 60 min pulse and 18 hr chase in vitro. Periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining of unosmicated thin sections localized vicinal glycol-containing complex carbohydrates in Golgi-associated small vesicles. These vesicles lacked HID-TCH-SP staining and apparently contained neutral glycoprotein. They frequently bordered, in a rosette arrangement, the immature morular granules, but not the more mature primary granules. The PA-TCH-SP method localized complex carbohydrates in the rim of granules precursors and enclosed a spherule or morula, but failed to stain the sulfate-containing material in the morulas or spherules. PA-TCH-SP reactivity was diffusely distributed in moderately mature granules and was decreased in fully mature granules. These results indicate that heterophil primary granule contain several complex carbohydrates including O-sulfated and N-sulfated glycosaminoglycans, as well as vicinal glycol-containing glycoproteins. These complex carbohydrates are transported to immature primary granules by different Golgi-derived organelles. The complex carbohydrates are subsequently distributed differently within primary granules and become masked to staining as the granule matures.


Subject(s)
Bone Marrow Cells , Glycoproteins/metabolism , Glycosaminoglycans/metabolism , Granulocytes/physiology , Animals , Autoradiography , Cytoplasmic Granules/physiology , Granulocytes/ultrastructure , Histocytochemistry , Microscopy, Electron , Rabbits , Subcellular Fractions/metabolism
16.
Cancer Res ; 39(10): 3834-44, 1979 Oct.
Article in English | MEDLINE | ID: mdl-289435

ABSTRACT

Leukemic myeloblasts containing abnormal granules were studied with ultrastructural, cytochemical, and thymidine labeling techniques to evaluate defects in granulogenesis and proliferation. Giant granules (1 to 3 micron in diameter) and Auer rods were observed in leukemic cells from two patients, and only rarely were both abnormal granule types observed in the same cell. The lysosomal origin of these abnormal granules was demonstrated by their content of peroxidase, esterase, and anionic glycoconjugates. Fusion of small dense granules (less than 0.2 micron in diameter) appeared to be increased in cells containing Auer rods and/or giant granules, but fusion of intact primary granules (0.2 to 0.4 micron in diameter) and sequestration of cytoplasmic contents were observed only in giant granules and not in Auer rods. Although the small granules that fused to form giant granules and Auer rods appeared similar, there was no evidence for transformation of giant granules into Auer rods. In one patient, cells with abnormal granules could easily be distinguished from the larger population of cells that lacked abnormal granules. The perturbation of these two distinct populations by chemotherapy was evaluated with thymidine labeling experiments. A high percentage (2- or 3-fold greater) of the abnormally granulated myeloblasts incorporated tritiated thymidine when compared to myeloblasts without abnormal granules in the same specimen. This difference could have resulted from an underlying metabolic defect which affected both granulogenesis and cell division. These results demonstrate that the formation of giant granules in leukemic cells is morphologically similar to that observed in the Chediak-Higashi syndrome and that leukemic cells with abnormal granules may differ cytokinetically from uninvolved leukemic cells.


Subject(s)
Cytoplasmic Granules/ultrastructure , Leukemia, Myeloid, Acute/ultrastructure , Cell Division , Child , Female , Hematopoiesis , Histocytochemistry , Humans , Infant , Kinetics , Leukemia, Myeloid, Acute/metabolism , Microscopy, Electron , Thymidine/metabolism
17.
Am J Pathol ; 96(1): 85-100, 1979 Jul.
Article in English | MEDLINE | ID: mdl-464028

ABSTRACT

Lead is a universal environmental contaminant absorbed largely through the gastrointestinal tract by unknown mechanisms. Because lead absorption is influenced by iron content in the body and diet, we used ultrastructural radioautography and cytochemistry to study absorption of physiologic lead doses in the rat duodenal epithelial cell and compared these findings to those previously reported for iron absorption. Rat duodenal loops exposed in vivo to 210Pb for 1 minute demonstrated the majority of labels on the microvilli, terminal web, and apical cytoplasm. Specimens exposed to radiolead for 10 minutes demonstrated more abundant labeling with a relative increase in labeling of epithelial cell mitochondria, nuclei and basal cytoplasm, as well as phagocytic cells, endothelial cells, and circulating erythrocytes of the lamina propria. Timm's sulfide-silver method localized trace metals in epithelial cells. After administration of lead, a significant increase in staining was observed in microvilli, mitochondria, non-membrane-bound cytoplasm, and nuclear chromatin. The rapid appearance of absorbed lead in epithelial cell mitochondria and nuclei, as well as phagocytic cells in the lamina propria, was distinctly different from that reported for absorbed iron and suggests different mechanisms for the subcellular transport of these cations. The combination of radioautography and Timm's sulfide-silver staining provides the specificity and resolution needed for ultrastructural evaluation of lead absorption and should be useful in further studies of lead metabolism.


Subject(s)
Duodenum/metabolism , Intestinal Absorption , Lead/metabolism , Animals , Autoradiography , Cell Nucleus/metabolism , Cytoplasm/metabolism , Epithelium/metabolism , Histocytochemistry , Male , Microvilli/metabolism , Mitochondria/metabolism , Rats
19.
Am J Pathol ; 93(3): 707-27, 1978 Dec.
Article in English | MEDLINE | ID: mdl-717544

ABSTRACT

Conventional ultrastructural autoradiographic and morphologic studies of the duodenal mucosal cell have generally corroborated physiologic observations of iron absorption, but such methods have limited resolution and fail to distinguish ferric and ferrous iron. This study describes the application of the Prussian blue reaction as an electron microscopic cytochemical stain to the investigation of inorganic iron absorption in iron-deficient, normal, and iron-loaded rats. Ferrous iron is converted to ferric iron at the microvillus membrane. Subsequently intraepithelial ferric iron appears bound to a non-heme acceptor substance in microvilli and later appears as small non-membrane-bound stain deposits which are concentrated in the apical cytoplasm. The appearance of larger stain deposits in the lateral intercellular spaces, in the basal extracellular spaces, and along the intraluminal and extraluminal outer plasmalemma of adjacent endothelial cells of the lamina propria suggests passage of iron from epithelial cells through the lamina propria to blood vessels. The extreme sensitivity of the method compared with simultaneous ultrastructural autoradiographic techniques is demonstrated and suggests usefulness of the method in further studies of iron metabolism.


Subject(s)
Intestinal Absorption , Intestinal Mucosa/metabolism , Intestine, Small/metabolism , Iron/metabolism , Animals , Autoradiography , Duodenum/metabolism , Duodenum/ultrastructure , Endothelium/metabolism , Endothelium/ultrastructure , Ferric Compounds/metabolism , Ferrous Compounds/metabolism , Intestinal Mucosa/ultrastructure , Intestine, Small/ultrastructure , Male , Methods , Microscopy, Electron , Prussian Blue Reaction , Rats
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