Direct in situ hybridization for rapid detection of cytomegalovirus in bronchoalveolar lavage

Rapid detection of cytomegalovirus (CMV) from pulmonary specimens in immunosuppressed persons may provide an origin for pneumonia. In situ DNA hybridization has been effective for detection of CMV in otherwise nondiagnostic histologic material. Studies comparing bronchoalveolar lavage (BAL) with open-lung biopsy have shown the former to be superior in detecting most pulmonary pathogens affecting immunocompromised patients. Fifty consecutive BAL specimens were studied to compare direct in situ DNA hybridization, routine tissue culture, and conventional cytologic examination to assess the efficacy of the hybridization technic to rapidly detect CMV. Using tissue culture as the standard, a sensitivity of 90% (28 of 31) and specificity of 63% (12 of 19) were observed with the CMV probe. Discrepant results between the probe and tissue culture were present in ten cases. There were seven probe-positive, culture-negative cases, three of which had systemic CMV infection, including two patients with inclusions noted by conventional cytologic examination. Three probe-negative, culture-positive cases were found. In the authors' laboratory, the predictive value of a positive CMV probe is 80% (28 of 35). In contrast to the probe, conventional cytologic examination revealed CMV inclusions in only 23% (7 of 31) of the culture-positive cases. An average of 21 days was required for CMV cultures to become positive; probe results were available within 24 hours. The authors conclude direct in situ DNA hybridization is a useful rapid method for the detection of CMV in BAL specimens submitted for cytologic examination.

Monoclonal antibodies to human malignant mesothelioma

Murine monoclonal antibodies were used to identify tumor-cell membrane antigens on a new human mesothelioma cell line. Hybridomas were constructed by fusing SP2/0 mouse myeloma cells with spleen cells from Balb/C mice immunized by the human mesothelioma cell line MT-1. Hybridoma antibody was detected in 55/672 microculture wells that reacted to these MT-1 tumor cells by an indirect 125I-protein A binding assay. Six cultures produced antibody binding selectively to the MT-1 tumor cells but not to a human lymphoblastoid cell line. These six hybridomas were cloned: three were IgG and three were IgM antibodies. One monoclonal, MAb 45, reacted with 4 of 7 human mesothelioma cell lines but with only 1 of 11 carcinomas, 1 of 3 sarcomas, 4 of 11 melanomas, and 0 of 5 lymphoid lines. The other five monoclonals had a much broader cross-reactivity. Using an immunoperoxidase technique, MAb 45 bound to mixed-type malignant mesotheliomas but not to normal lung and pleura. The specificity of MAb 45 for diffuse mesotheliomas and the low cross-reactivity with carcinomas and normal adjacent tissues suggest that this monoclonal may be clinically useful.

Deformation analyses in cell and developmental biology. Part I--Formal methodology

This study presents a computational approach for the deformation analyses of problems in cell and developmental biology. Cells and embryos are viewed mechanically as axisymmetric shell-like bodies containing a body of incompressible material. The analysis approach is based on the finite element method. It is comprised of three finite element ingredients: an axisymmetric shell/membrane element valid for modeling finite bending, shearing and stretching; a volume constraint algorithm for modeling the membrane-bound incompressible material; and a contact algorithm for modeling the mechanical interactions between deformable bodies. Part II of this study will demonstrate how these three ingredients can be applied to analyze mechanical experiments on cells. This same method is also useful for simulating embryonic shape changes during development.

Deformation analyses in cell and developmental biology. Part II--Mechanical experiments on cells

This study employs the finite element approach developed in Part I to analyze mechanical experiments on cells. It views cells as axisymmetric membrane structures containing a body of incompressible material, and models the mechanical contact between a cell and the loading apparatus by a contact algorithm. Since the method is valid for analyzing axisymmetric shell-like bodies with arbitrary shapes, it treates various mechanical experiments on cells in a unified manner. For demonstration purposes, three commonly used mechanical experiments on cells are considered; the compression experiment; the suction (micropipette aspiration) experiment; and the magnetic particle experiment. Based on an estimate of the mechanical property data for unfertilized sea urchin eggs, this analysis method predicts the responses for all three experiments using the same assumptions and approximations. This parallel treatment gives a broad basis for data correlation with experiments. The method also provides insights into mechanical experiments not offered by other approximate methods. For example, it gives the distributions of tensions and stretches on the cell cortex, and suggests the role of friction in the suction experiment.

Na+-H+ exchange and Na+-dependent transport systems in streptozotocin diabetic rat kidneys

The streptozotocin-induced diabetic rat was used to test the hypothesis that Na+-H+ exchange activity in the proximal tubule luminal membrane would be increased in association with renal hypertrophy, altered glomerular hemodynamics, enhanced filtered load and tubular reabsorption of Na+, and stimulated Na+ pump activity in the basolateral membrane, previously reported characteristics of this experimental animal model. Amiloride-sensitive H+ gradient-dependent Na+ uptake and Na+ gradient-dependent H+ flux were increased in brush-border membrane vesicles from the streptozotocin-treated animals. Na+ gradient-dependent uptakes of phosphate, D-glucose, L-proline, and myoinositol were decreased in the drug-induced diabetic animals. These membrane transport alterations were not found when the streptozotocin-diabetic animals were treated with insulin.

Calcium and renal adaptation to a phosphate load in the thyroparathyroidectomized rat

Infusion of phosphate into thyroparathyroidectomized rats on a normal phosphorus diet caused a decrease in net phosphate reabsorption, even though the plasma concentration of phosphate continued to rise. This response was expressed at the level of the proximal tubule brush-border membrane and was coincident with a decrease in sodium-dependent phosphate uptake in membrane vesicles. Kinetic experiments indicated that the increased phosphate load caused a decrease in the Vmax of the membrane uptake system with no change in the apparent Km for phosphate. The infusion of phosphate resulted in a lowered plasma calcium concentration, and it was previously hypothesized that the inhibition of maximal phosphate reabsorption was mediated by the hypocalcemia. When the fall in plasma calcium was prevented by the simultaneous infusions of calcium and phosphate, the reduction in maximal phosphate reabsorption was blunted; however, the phosphate infusion-induced inhibition of brush-border membrane vesicle phosphate uptake was still evident. Thus a major discrepancy was found to the general concept that renal phosphate reabsorption in vivo correlated positively with sodium-dependent phosphate uptake activity in proximal tubule brush-border membrane vesicles. Several possible explanations to account for this anomaly were discussed. It was also found that calcium infusion into saline-infused thyroparathyroidectomized rats slightly increased maximal phosphate reabsorption but did not affect phosphate uptake in the membrane vesicles.

Endocrine and tumor differentiation markers in poorly differentiated small-cell carcinoids of the cervix and vagina

Immunoreactivity for endocrine peptides (serotonin, gastrin, somatostatin, insulin, corticotropin, calcitonin, neurotensin, vasoactive intestinal peptide, and bombesin), cytoskeletal proteins (high and low molecular weight keratins), and tumor differentiation markers (chromogranin, neuron-specific enolase, carcinoembryonic antigen, S100 protein, and Grimelius stain) was sought on nine cervical and one vaginal poorly differentiated small-cell carcinoids. Dense-core secretory granules were ultrastructurally identified in all cases (seven of ten) in which tissue was available for electron microscopy. Immunoreactivity for endocrine secretory products was rarely noted, and only in a minority cell population (serotonin in two of ten). The majority of the tumors exhibited immunoreactivity for low molecular weight keratin (AE1/AE3 in eight of ten; CAM 5.2 in seven of nine), and three of ten tumors focally expressed high molecular weight keratin. Among the markers of neuroendocrine differentiation, neurospecific enolase was more frequently expressed (ten of ten) than chromogranin (five of ten) or argyrophilia (three of ten). Carcinoembryonic antigen was present in eight of ten tumors. S100 protein was absent in all cases. In summary, poorly differentiated small-cell carcinoids of the lower female genital tract, similarly to other small-cell endocrine tumors, occasionally exhibit focal glandular and squamoid differentiation, and only relatively infrequently or focally express immunohistochemically detectable endocrine secretory products, chromogranin, and argyrophilia.

The presence of bacteria in the oral epithelium in periodontal disease. II. Immunohistochemical identification of bacteria

Serial histological sections of gingiva obtained from each of six advanced adult periodontitis, two localized juvenile periodontitis and two periodontally healthy patients were used for specific identification of bacteria within the oral epithelium and adjacent connective tissue. Healthy gingival biopsies served as controls. Sections from patients and control biopsies were Gram-stained and also screened with antibacterial sera associated with the peroxidase immunocytochemical technique for specific bacterial identification. The "Pop-off" electron microscopic technique was also used to further demonstrate the bacterial nature of peroxidase-stained material. In addition, the possible correlation between bacteria and areas of possible reduced keratinization was investigated. The results showed that sections of orthokeratinized healthy gingiva did not contain bacteria. Gram-stained sections from diseased sites contained large numbers of bacteria in the oral epithelium and adjacent connective tissue. Bacteroides gingivalis and to a lesser extent Capnocytophaga gingivalis were found in periodontitis, and Actinobacillus actinomycetemcomitans was found in juvenile periodontitis when the immunoperoxidase technique was used. The bacterial nature of peroxidase-stained material was confirmed by the "pop-off" technique. In the disease biopsies, bacterial presence was correlated with areas of reduced amounts of keratin suggesting that the oral epithelium may be a portal of entry for bacteria into gingival tissues.

Neuroendocrine carcinoma of the skin: an immunohistochemical study of tumor markers and neuroendocrine products

Fifteen neuroendocrine carcinomas of the skin (Merkel cell tumors) were stained within the constraints of tissue availability by the Grimelius method and immunohistochemically for keratin, neuron-specific enolase (NSE), carcinoembryonic antigen (CEA), S-100, common leukocyte antigen (CLA), met-enkephalin, bombesin, calcitonin, ACTH, gastrin, and somatostatin. Focal argyrophilia was present in 5 of 12 tumors. All tumors tested demonstrated immunoreactivity for NSE and 5 tumors were positive for keratin. One tumors appeared to demonstrate focal ACTH-like immunoreactivity, but otherwise no immunoreactivity for the above mentioned polypeptide hormones was noted in 11 completely studied tumors. One tumor contained histologically obvious areas of squamous differentiation in addition to areas of Merkel cell tumor. In various tumors, keratin immunoreactivity was present either in areas of histologically obvious squamous differentiation, in randomly scattered single cells not histologically identifiable as squamous, or in a paranuclear dot-like distribution. Immunoreactivity for CEA, S-100 and CLA was not present in any tumors. The lack of met-enkephalin and the presence of squamous differentiation in these tumors indicates multidirectional differentiation in a fashion not phenotypically typical of Merkel cells.

Neurulation and the cortical tractor model for epithelial folding

We present here a new model for epithelial morphogenesis, which we call the 'cortical tractor model'. This model assumes that the motile activities of epithelial cells are similar to those of mesenchymal cells, with the added constraint that the cells in an epithelial sheet remain attached at their apical circumference. In particular, we assert that there is a time-averaged motion of cortical cytoplasm which flows from the basal and lateral surfaces to the apical region. This cortical flow carries with it membrane and adhesive structures that are inserted basally and resorbed apically. Thus the apical seal that characterizes epithelial sheets is a dynamic structure: it is continuously created by the cortical flow which piles up components near where they are recycled in the apical region. By use of mechanical analyses and computer simulations we demonstrate that the cortical tractor motion can reproduce a variety of epithelial motions, including columnarization (placode formation), invagination and rolling. It also provides a mechanism for driving active cell rearrangements within an epithelial sheet, while maintaining the integrity of the apical seal. Active repacking of epithelial cells appears to drive a number of morphogenetic processes. Neurulation in amphibians provides an example of a process in which all four of the above morphogenetic movements appear to play a role. Here we reexamine the process of neurulation in amphibians in light of the cortical tractor model, and find that it provides an integrated view of this important morphogenetic process.

Evaluation of an antibody to human milk fat globule antigen in the detection of metastatic carcinoma in pleural, pericardial and peritoneal fluids

An antibody to human milk fat globule-2 (HMFG-2) antigen was investigated to assess its value in detecting tumors in pleural, pericardial and peritoneal fluids. One hundred forty consecutive fluids were evaluated using the avidin-biotin complex (ABC) technique. Conventional cytology and HMFG-2-stained smears were compared using the former as the standard for tumor detection. Discrepant results were found in 15 specimens (8 false negatives and 7 false positives). Causes for discrepancy between the methods included lack of HMFG-2 antigen on tumor cells, random sampling error and endometrial cells ectopically located in the pelvic cavity or introduced during uterine instrumentation. We conclude staining for HMFG-2 may be a useful adjuvant technique for the detection of rare tumor cells in body fluids provided there is a high index of suspicion of metastasis from an HMFG-2-positive primary neoplasm.

Glucocorticoids and metabolic acidosis-induced renal transports of inorganic phosphate, calcium, and NH4

The initial rate (5 s) of Na+-dependent inorganic phosphate (Pi) uptake in brush-border membrane vesicles isolated from rat proximal tubule was decreased in metabolic acidosis, 0.42 +/- 0.02 vs. 0.59 +/- 0.05 nmol/mg protein, in vesicles from control animals. Phosphate, ammonium, and Ca2+ excretions were increased 100, 600, and 56%, respectively. These changes in brush-border Pi transport and urinary excretion of ions were largely dependent on intact adrenal glands. After adrenalectomy there were no significant changes in brush-border Pi transport, Pi, and Ca2+ excretion, whereas ammonium excretion increased only 300% compared with controls. When the glucocorticoid dexamethasone was administered to adrenalectomized animals, it mimicked the effects of metabolic acidosis both in the presence and the absence of metabolic acidosis. The initial rate of brush-border Pi transport was decreased by dexamethasone administration to 0.37 +/- 0.04 nmol/mg protein in adrenalectomized acidotic animals and 0.39 +/- 0.03 nmol/mg protein in adrenalectomized animals. Dexamethasone administered to adrenalectomized acidotic animals increased Pi, ammonium, and Ca2+ excretion 190, 690, and 23%, respectively. Dexamethasone administered to nonacidotic adrenalectomized animals increased Pi ammonium and Ca2+ excretion 165, 240, and 31%, respectively. We conclude that changes in Pi, ammonium, and Ca2+ excretion observed during metabolic acidosis were dependent on intact adrenal glands and that glucocorticoids administered to adrenalectomized acidotic or nonacidotic animals mimicked the changes observed in acidotic animals with intact adrenal glands.

[Serum HSV-2 antibody in males from high and low incidence areas of cervical cancer]

Serum HSV-2 antibody in male from high and low incidence areas of cervical cancer was assayed by enzyme-immuno-slide method. The results show that the geometric mean titer of the serum HSV-2 antibody in the male from high incidence area (413.5) is significantly higher than that from the low incidence area (210.4) (P less than 0.01). It indicates that the high cancer incidence might be related to the high HSV-2 infection rate in the spouses of the cervical cancer patients.

Virus-neutralizing activity, serologic heterogeneity, and retrovirus isolation from homosexual men in the Los Angeles area

Human retroviruses have been causally associated with the development of the acquired immune deficiency syndrome (AIDS) in groups of individuals at high risk including intravenous drug users, hemophiliacs, and homosexual men. Aside from classic AIDS, homosexual men also develop persistent generalized lymphadenopathy (PGL) which is considered a part of the AIDS-related complex (ARC). We have isolated 70 strains of retroviruses related to human T-lymphotropic viruses type III (HTLV-III) from patients with PGL, AIDS, or ARC. analyses of sera from these patients indicated a high degree of serologic heterogeneity in the antibody titers and their reactivities toward various HTLV-III viral proteins. In addition, we have detected virus-neutralizing antibodies in approximately 50% of the serum samples tested from patients with PGL or AIDS. This is the first comprehensive virologic and serologic report on more than 100 patients studied at one institution in Los Angeles.

Fine needle aspiration diagnosis of malignant lymphoma with confirmation by immunoperoxidase staining

Cytospin preparations of fine needle aspirates in 14 cases of suspected lymphoma were studied by immunoperoxidase techniques. The combination of cytologic smears and immunoperoxidase studies resulted in a working diagnosis in 13 of the 14 cases. The immunologic markers in conjunction with the cytologic appearance of the aspirates were reliable and consistent in differentiating between malignant and benign lymphoproliferative lesions and in determining the B-cell or T-cell nature of the process.

Immunoperoxidase study of lymphomas. Comparison of a one-step frozen section technic with indirect methods on paraffin sections

Fifty cases of non-Hodgkin's lymphoma (15 nodular and 35 diffuse) were studied to determine the sensitivity, specificity, and ease of several different immunoperoxidase methods. The methods included a rapid, simple one-step immunoperoxidase procedure on frozen sections compared with indirect immunoperoxidase technics on paraffin sections. The frozen-section immunoperoxidase technic stained 15 of 15 nodular lymphomas and 24 of 35 diffuse lymphomas for monoclonal light chain. The majority of the diffuse lymphomas that did not stain for light chains were morphologically and immunohistochemically consistent with T-cell lymphomas. The indirect method on B-5 and formalin-fixed tissues only rarely displayed monoclonal staining for nonplasmacytoid small cell lymphomas but did stain some large cell lymphomas and a majority of plasmacytoid lymphomas for monoclonal light chain. The frozen section technic presented in this report is sufficiently sensitive and reliable to detect immunoglobulins in any morphologic subtype of B-cell lymphoma, whereas paraffin-embedded tissues have only limited application.

Chronic active hepatitis of hepatitis B and non-A, non-B etiology. Immunohistochemical localization of hepatitis B core antigen in a series of needle biopsies

Hepatitis B core antigen (HBcAg) was immunohistochemically demonstrated in 19 of 30 needle liver biopsies (63%) of chronic active hepatitis (CAH) from 15 of 24 patients (63%) whose serum contained hepatitis B surface antigen (HBsAg). The percentage of hepatocytes with nuclear and/or cytoplasmic immunoreactivity was quantified in each biopsy specimen, and these percentages were then compared with the amount of HBsAg and the degree of inflammation within the biopsy specimen. The percentage of HBcAg-positive hepatocytes in a biopsy specimen was greatest in those specimens that contained the most HBsAg, although this finding was not statistically significant. The percentage of HBcAg-positive hepatocytes was greatest in those specimens having the least inflammatory activity, and this was statistically significant (P less than .01). Also, the percentage of biopsy specimens containing HBcAg was increased in those groups with lesser inflammatory activity (P less than .01). By staining for both HBcAg and HBsAg, the detection rate of hepatitis B (HB)-related antigens rose to 27 of 30 biopsies (90%) in 22 of 24 patients (92%).

Disseminated bombesin-producing carcinoid tumor of pulmonary origin

A case of a bombesin-producing carcinoid tumor of the lung is reported. Morphologically, the tumor was a typical argentaffinic carcinoid which contained bombesin as demonstrated by diffuse granular cytoplasmic staining using the immunoperoxidase method. Electron microscopy revealed dense-core granules measuring 100-150 nm, consistent with bombesin-containing endocrine cells. In man, bombesin-producing endocrine cells are found predominantly in the bronchopulmonary tree and scattered throughout the intestinal tract. The majority of previously reported bombesin-producing tumors have arisen, as in this case, in the lung; thus the demonstration of bombesin-like immunoreactivity in a widely metastatic tumor should direct the search for a primary lesion to the lung. Bombesin is known to have gastrin-releasing hormone activity. The presence of a gastric ulcer in the present patient raised the possibility of a bombesin-mediated Zollinger-Ellison-like syndrome, an association not previously described.

Phosphate excretion in uremic rats: effects of parathyroidectomy and phosphate restriction

As progressive renal failure develops, phosphate excretion per functioning nephron increases, thus preserving homeostasis. To test whether dietary phosphate supply might contribute to the regulation of renal phosphate excretion in the uremic setting, groups of male Sprague-Dawley rats that were either parathyroidectomized (PTX) or sham PTX (S-PTX) and either five-sixths nephrectomized (Nx) or sham Nx (S-Nx) were studied following a 4-wk dietary regimen consisting of 0.1 or 0.7% phosphate. For Nx rats fed the 0.7% phosphate diet the fractional excretion of phosphate (FEPi) was enhanced (47 +/- 6 vs. 21 +/- 3%) and the maximum tubular reabsorption of phosphate per milliliter GFR (TmPi/GFR) was suppressed (1.65 +/- 0.19 vs. 2.33 +/- 0.19 mumol/ml). FEPi was unchanged by PTX in these Nx animals (42 +/- 6 vs. 47 +/- 6%). TmPi/GFR remained suppressed in PTX, NX animals when compared with S-Nx, PTX controls (3.38 +/- 0.33 vs. 5.07 +/- 0.41 mumol/ml). For rats fed the 0.1% phosphate diet Nx did not affect TmPi/GFR in either S-PTX (5.40 +/- 0.43 vs. 4.97 +/- 0.34 mumol/ml) or PTX (7.03 +/- 0.23 vs. 6.98 +/- 0.21 mumol/ml) animals. For both S-Nx and Nx animals the effects of PTX and dietary phosphate restriction on TmPi/GFR were independent and additive. In all groups of animals, tubular reabsorption of phosphate per milliliter GFR (TRPi/GFR) dropped acutely with continued infusion of phosphate once TmPi/GFR was achieved. Thus, a resetting of TRPi/GFR occurs among Nx rats in response to both chronic dietary phosphate deprivation and acute intravenous phosphate loading.(ABSTRACT TRUNCATED AT 250 WORDS)

Sodium gradient-dependent calcium uptake in renal basolateral membrane vesicles. Effect of parathyroid hormone

The Na+/Ca2+ exchange system in rat renal cortex basolateral membrane vesicles was studied. Uptake and efflux of Ca2+ in the membrane vesicles were stimulated by trans-Na+. The enhancement of Ca2+ uptake by the intravesicular greater than extravesicular Na+ gradient was inhibited by ionophores that dissipated the gradient, and was increased by an outside negative membrane potential. Na+-dependent Ca2+ uptake was saturable with respect to both Ca2+ and Na+. A [Ca2+]0.5 of 8 microM was calculated. The relationship between Na+ concentration and rate of Ca2+ efflux was sigmoidal; a [Na+]0.5 of 15 mM and a Hill coefficient of 2.5 were estimated. Removal of parathyroid glands from the rats resulted in a 40% decrease in the Na+-dependent Ca2+ uptake. Infusion of parathyroid hormone (the synthetic tetratriacontapeptide) into these animals fully restored the activity. The isolated basolateral membrane possessed parathyroid hormone-sensitive adenylate cyclase. These findings may suggest a mechanism by which parathyroid hormone regulates the reabsorption of Ca2+ in the kidney.

Renal adaptation to phosphate load in the acutely thyroparathyroidectomized rat: rapid alteration in brush border membrane phosphate transport

The sustained in vivo infusion of phosphate into thyroparathyroidectomized rats resulted, after 1 h, in a marked decrease in net phosphate reabsorption, even though the plasma concentration of phosphate continued to rise. This response to phosphate infusion was expressed at the level of the proximal tubule brush border membrane. Within 40 min of the initiation of the infusion the Na+-dependent phosphate uptake system in isolated membrane vesicles was decreased. Phosphate uptake in the absence of Na+, Na+-dependent D-glucose uptake, and 22Na+ uptake were not affected. These findings demonstrate the locus of this parathyroid hormone-independent adaptation and indicate the rapidity with which the membrane transport system is regulated.

The withdrawal of benztropine mesylate in chronic schizophrenic patients

In this double-blind, four-week study, 28 chronic schizophrenic patients receiving neuroleptic medication plus the antiparkinsonian drug, benztropine mesylate, were either switched to placebo or maintained on benztropine. Patients withdrawn from benztropine reliably increased their overall scores on the Wechsler Memory Scale in comparison with the drug group. Sub-test scores suggest that deficits in attention and concentration were induced by treatment with benztropine. Psychotic decompensation appeared to develop simultaneously with extrapyramidal symptoms (EPS) in some patients, but only 14.2 per cent of the placebo group experienced extrapyramidal symptoms severe enough to require resumption of benztropine therapy. It is suggested that antiparkinsonian agents should be prescribed only if and when EPS occur.

Pulmonary carcinoids. Immunohistochemical demonstration of brain-gut peptides

Antisera raised against serotonin, gastrin, somatostastin, motilin, bombesin, calcitonin, secretin, glucagon, ACTH, neurotensin, and pancreatic polypeptide carboxyterminal hexapeptide were employed to immunohistochemically stain seven pulmonary carcinoids. Argentaffin and argyrophil stains were also performed on all cases. Serotonin-like immunoreactivity was present in four tumors, pancreatic polypeptide-like immunoreactivity in four tumors, bombesin-like immunoreactivity in two tumors and ACTH-like immunoreactivity in one tumor. The cells shown to contain neuroendocrine products constituted a minority cell population in all tumors except the ACTH-immunoreactive tumor. This study suggests that pulmonary carcinoids, like their abdominal counterparts, contain a variety of neuroendocrine products, and may produce more than one neuroendocrine product. Serotonin and pancreatic polypeptide-like immunoreactivity were the most prevalent neuroendocrine products demonstrable in this study.

Phosphate uptake by renal membrane vesicles of rabbits adapted to high and low phosphorus diets

Renal adaptation to changes in phosphate intake was studied by comparing phosphate uptake by proximal tubule brush border membrane vesicles from rabbits on a relatively high or low phosphorus diet. The low phosphorus diet increased Na+ gradient-dependent phosphate uptake. Uptake in the absence of Na+ and in the presence of Na+, but no gradient, was not significantly affected. The phosphorus diet did not alter Na+ gradient-dependent D-glucose and L-proline uptake. The low phosphorus diet increased Vmax; affinity for phosphate was not appreciably changed. At all concentrations of extravesicular Na+, phosphate uptake was higher in membrane vesicles from animals fed the low phosphorus diet; the kinetics of the phosphate uptake system, with respect to Na+, was also altered by the change in dietary phosphate. These findings suggest that adaptation involves an alteration in the rate of translocation of the Na+-phosphate carrier when energized by a Na+ gradient driving force rather than a change in the number of Na+-phosphate carrier sites. With membrane vesicles from rabbits fed a low phosphorus diet, phosphate uptake increased several-fold when the pH of the uptake medium was raised, whereas with membrane vesicles from animals fed a high phosphorus diet the enhancement of uptake with alkalinization was relatively small. Irrespective of the diet, divalent phosphate was the probable preferred species for transport. Dietary adaptation was associated, however, with an alteration in the pH dependency of the transport system per se. These findings provide evidence that the adaptation of the kidney phosphate transport system to dietary phosphate load involves an intrinsic change in the Na+-phosphate carrier.

The neuroendocrine products of intestinal carcinoids. An immunoperoxidase study of 35 carcinoid tumors stained for serotonin and eight polypeptide hormones

The intestinal carcinoid tumors of 26 patients were stained for the presence of serotonin, gastrin, somatostatin, motilin, secretin, glucagon, pancreatic polypeptide, ACTH, and neurotensin. Argentaffin and argyrophil stains were also performed in all cases. Thirty-five separate tumors (counting metastases and multiple primaries) from the 26 patients were studied. Serotonin was present in 30 of the 35 tumors. Nineteen tumors contained serotonin only. Fourteen tumors contained multiple neuroendocrine products. One tumor contained gastrin only. One tumor did not stain immunohistochemically, but was argyrophilic. Metastatic deposits were studied in nine patients. Some metastases produced the identical neuroendocrine products as the primary tumor, whereas others produced either additional or fewer hormones than the primary tumor. Moreover, different metastases from the same primary tumor were observed to produce different hormones. Argyrophilic cells were present in all cases and were much more numerous than cells staining by immunohistochemistry. Argyrophilic cells probably contain monoamines and polypeptide hormones in addition to those studied in this series. The argyrophil stain was the best general stain in this study for the demonstration of neuroendocrine cells. Argentaffin staining was negative in ten cases that were serotonin positive and two argentaffin positive cases were serotonin negative. The carcinoid syndrome, as clinically defined by the presence of flushing and diarrhea, was noted in five patients, all of whom had serotonin-containing small bowel carcinoids. Endocrine-related symptoms were not clinically appreciated in the remaining patients.

Cytochemical and competitive protein binding assays for estrogen receptor in breast disease. A comparative study of 62 cases

Estrogen receptor content of breast lesions was estimated using a fluorescent cytochemical technique and a competitive protein binding assay. Of 48 cancers examined, an equal proportion contained significant quantities of receptor by either method (62.5%). The concordance between methods for individual patients was also 62.5%. A greater proportion (26%) of patients younger than 45 years of age had receptor-positive cancers using the cytochemical method than were found by the biochemical method (10%). Benign breast disease was also studied using the fluorescent cytochemical method. A greater proportion of lesions containing estrogen receptors was found compared with that cited in the literature for the competitive protein-binding assay. Because of the methodologic simplicity of the fluorescent cytochemical method, further study for routine use is indicated.

A colonic adenocarcinoma with argentaffin cells. An immunoperoxidase study demonstrating the presence of numerous neuroendocrine products

A well-differentiated colonic adenocarcinoma containing large numbers of gastrointestinal neuroendocrine cells is presented. The presence of neurosecretory granules was confirmed by electron microscopy. Immunocytochemistry showed large numbers of serotonin-containing tumor cells and lesser numbers of somatostatin, gastrin, motilin, secretin and neurotensin-containing cells. Some of these hormones are not normally present in the colon in significant numbers of cells. The presence of several cell types within a single tumor supports the concept that the normal epithelial cells of the gastrointestinal mucosa are derived from a common endodermal stem cell. There exists a spectrum of tumors ranging from the classical adenocarcinoma to the classical carcinoid, and this report identifies the position of this case within that spectrum.

Acinar-endocrine cell tumor of the pancreas. Report of a pancreatic tumor containing both zymogen and neuroendocrine granules

A case of pancreatic tumor with features of both an acinar cell and an endocrine cell tumor is presented. The histologic appearance of the tumor by light microscopy was consistent with the appearance of either an islet cell tumor or an acinar cell tumor. Electron microscopy revealed two distinct populations of membrane bound granules within the same tumor cells; namely, a small granule measuring 100-200 nanometers in diameter with a narrow halo separating it from the granule membrane, and a large granule measuring 400-500 nanometers in diameter and having a closely applied membrane. The smaller granules have the characteristic appearance of gastroenteropancreatic (GEP) endocrine-cell granules. The large granules are greater in size than neuroendocrine granules, their morphologic structure is most consistent with that of zymogen granules, and a positive lipase stain supported the presence of zymogen granules within the tumor. The occurrence of both neuroendocrine and zymogen granules within the same cell has been previously described in the "intermediate cell" of the pancreas, but not to our knowledge in a tumor of the pancreas. The finding of both endocrine and exocrine granules within a single cell indicates a histogenetic relationship between the pancreatic endocrine and exocrine cells, and may represent the first reported case of a neoplastic proliferation of intermediate cells.

In vitro stimulation of phosphate uptake in isolated chick renal cells by 1,25-dihydroxycholecalciferol

Renal cells isolated from vitamin D-deficient chicks had an increased Na+-dependent phosphate uptake when preincubated with 1,25-dihydroxycholecalciferol [1,25-(OH)2D3]. Phosphate uptake in the absence of Na+ and methyl alpha-glucoside uptake dependent on Na+ were not affected. Phosphate uptake was stimulated 15% by 0.010 pM 1,25-(OH)2D3. Maximal enhancement of 30% was obtained with 100 pM. The uptake when fully stimulated by preincubation in vitro approximated the uptake of cells isolated from chicks that were previously repleted with 1,25-(OH)2D3 in vivo. Cells from repleted chicks were not stimulated additionally when preincubated with 1,25-(OH)2D3 in vitro. The increase in phosphate uptake could be measured after a 1-hr preincubation period; full response required at least 2 hr. Phosphate uptake induced by 1,25-(OH)2D3 was blocked by cycloheximide and actinomycin D. Enhancement of phosphate uptake was relatively specific for the 1,25-(OH)2D3 analog of vitamin D3. The potency order was 1,25-(OH)2D3 greater than 25-(OH)D3 = 1-(OH)D3 greater than 24,25-(OH)2D3 greater than D3. Kinetically, 1,25-(OH)2D3 increased the Vmax of the phosphate uptake system; the affinity for phosphate was unaffected. 3H-Labeled 1,25-(OH)2D3 was taken up by the isolated renal cells. It was estimated that the stimulation of phosphate uptake might be initiated by very few molecules of 1,25-(OH)2D3 per cell. It is proposed that 1,25-(OH)2D3 contributes importantly to the mechanisms by which phosphate transport is regulated in the kidney.

Effects of 1,25-(OH)2D3 administered in vivo on phosphate uptake by isolated chick renal cells

Renal cells from Vitamin D-deficient and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]-repleted chicks were isolated by a collagenase-hyaluronidase procedure. Exclusion of trypan blue and respiratory measurements indicate that the cells were functionally intact and metabolically active. The uptakes of phosphate and alpha-methylglucoside were stimulated markedly by Na+ in the extracellular medium. Phosphate uptake in the presence of Na+ was saturable with respect to phosphate concentration; half-maximal activity was obtained with approximately 0.2 mM. Three hours after 1,25-(OH)2D3 was injected into vitamin D-deficient chicks the Na+-dependent phosphate uptake by the isolated cells had increased about 40%, i.e., 2.00 compared with 1.44 nmol.min-1.mg protein-1. Phosphate uptake in the presence of K+ in the extracellular medium and alpha-methylglucoside uptake in the presence or absence of Na+ were unchanged. In a secondary response found 17 h after 1,25-(OH)2D3 injection, Na+-dependent phosphate uptake decreased. Serum concentrations of phosphorus and calcium were not measurably changed in the 3-h repleted bird, but both levels were increased 17 h after treatment. Administration of phosphate into vitamin D-deficient chicks, so that the serum concentration of phosphorus was raised to that of the 17-h 1,25-(OH)2D3 repleted animal, effected a comparable decrease in phosphate uptake. Serum calcium levels were not altered by this treatment. The actions of parathyroid hormone in stimulating adenylate cyclase and in inhibiting phosphate uptake were notably blunted in the vitamin D-deficient chick. Sensitivity to parathyroid hormone was not restored until several days after 1,25-(OH)2D3 repletion. These findings suggest that the initial response to 1,25-(OH)2D3, to increase renal phosphate uptake, and the secondary response, to decrease phosphate uptake, were by parathyroid hormone-independent processes. The results also indicate that the isolated renal cell represents an excellent model for studying the mechanism by which 1,25-(OH)2D3 regulates phosphate transport in the kidney.