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Lalos AT, Yeager HC, Weiss JP. Ascites and myxedema in a patient with polycystic disease of the kidney and liver. Am J Gastroenterol 1994; 89:2237-9. [PMID: 7977249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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McLean GK, Cekirge S, Weiss JP, Foster RG. Stent placement for iliac artery occlusions: modified "wire-loop" technique with use of the goose neck loop snare. J Vasc Interv Radiol 1994; 5:701-3. [PMID: 8000118 DOI: 10.1016/s1051-0443(94)71586-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Weiss JP. Using the nurse practitioner in the acute care setting. ASPEN'S ADVISOR FOR NURSE EXECUTIVES 1994; 9:4-6. [PMID: 8060724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Weiss JP, Mattei DM, Neville EC, Hanno PM. Primary treatment of radiation-induced hemorrhagic cystitis with hyperbaric oxygen: 10-year experience. J Urol 1994; 151:1514-7. [PMID: 8189559 DOI: 10.1016/s0022-5347(17)35289-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Radiation-induced hemorrhagic cystitis continues to cause frustration for patients and urologists alike. Virtually all present modes of treatment tend to yield short-term benefits and entail potentially devastating risk by virtue of the tissue destructive nature. We report our 10-year experience in the treatment of hemorrhagic radiation cystitis with hyperbaric oxygen therapy, a tissue-reparative method, in followup of our prior reports. A total of 13 patients who previously underwent radiation therapy for various pelvic malignancies had endoscopically or biopsy proved hemorrhagic cystitis. All but 1 patient experienced durable cessation of hematuria with minimal side effects following hyperbaric oxygen therapy. These results suggest hyperbaric oxygen therapy to be a significant weapon in the armamentarium for treatment of hematuria secondary to radiation-induced injury to the bladder.
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Weiss JP, McLean GK, Modic MT, Rees CR, Higashida RT. Double-blind study of a new nonionic contrast agent for digital subtraction arteriography. Invest Radiol 1994; 29 Suppl 1:S84-92. [PMID: 8071051 DOI: 10.1097/00004424-199405001-00016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
RATIONALE AND OBJECTIVES Since the development of the first low-osmolality contrast agent in 1969, a new group of ionic and nonionic compounds have emerged. These new agents have dramatically improved diagnostic imaging by exhibiting significant improvements in safety and technical efficacy over that of high-osmolality agents. This study was designed to compare the safety, tolerance, and technical efficacy of iopromide, a new low-osmolality, nonionic contrast agent, with that of both ioversol and iopamidol for digital subtraction angiography (DSA). METHODS One hundred fifty patients with conditions requiring intraarterial digital subtraction angiography were randomly assigned to receive 150 mg I/mL iopromide or either 160 mg I/mL ioversol or 128 mg I/mL iopamidol. Cerebral, aortovisceral, and peripheral arteriography was performed. RESULTS No significant difference was found in safety, tolerance, and technical efficacy between iopromide and ioversol. Iopamidol had significantly less technical efficacy than iopromide, but there were no significant differences in safety or tolerance between these two agents. CONCLUSIONS All three contrast media (CM) are useful for cerebral DSA. Although these agents were diagnostically adequate for use during aortovisceral and peripheral DSA, none was able to optimally opacify vessels during these studies in the concentrations administered.
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Cekirge S, Weiss JP, Foster RG, Neiman HL, McLean GK. Percutaneous retrieval of foreign bodies: experience with the nitinol Goose Neck snare. J Vasc Interv Radiol 1993; 4:805-10. [PMID: 8281004 DOI: 10.1016/s1051-0443(93)71978-8] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
PURPOSE The authors present their experience with the nitinol Goose Neck snare system in the retrieval of retained foreign bodies in 20 patients. PATIENTS AND METHODS Foreign bodies were located in the vascular system in 13 patients, urinary tract in four, biliary system in one, gastrointestinal tract in one, and the peritoneal space in one. All retrievals were performed with use of standard angiographic/interventional techniques. RESULTS Success was achieved in all cases without attendant complications. Foreign bodies removed included catheter and guide-wire fragments, an embolization coil, broken or occluded double pigtail catheters, a Wallstent, and a surgical laparotomy sponge. CONCLUSION All procedures were performed quickly, safely, and without difficulty. Because of its excellent torque control, positive grasping capacity, excellent radiopacity, lack of traumatic effect, and availability in different sizes appropriate for use in a wide variety of difficult anatomic spaces, the authors recommend that this device be considered the first choice for all foreign body retrieval procedures.
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Cekirge SH, Weiss JP, Foster RG, McLean GK. Stent placement in a splenic vein stenosis after TIPS creation. Radiology 1993; 189:197-8. [PMID: 8372193 DOI: 10.1148/radiology.189.1.8372193] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A hemodynamically significant splenic vein stenosis was found during placement of a transjugular intrahepatic portosystemic shunt in a patient with gastric variceal bleeding. A second stent was placed across the splenic vein stenosis, which was obstructing normal hepatopetal flow, causing venous hypertension in the splenic and short gastric veins. This produced a successful hemodynamic and angiographic result and, clinically, controlled the patient's bleeding.
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Cekirge S, Foster RG, Weiss JP, McLean GK. Percutaneous removal of an embolized Wallstent during a transjugular intrahepatic portosystemic shunt procedure. J Vasc Interv Radiol 1993; 4:559-60. [PMID: 8353354 DOI: 10.1016/s1051-0443(93)71921-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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Weiss JP, Feld M, Sclafani SJ, Scalea T, Vieux E, Trooskin SZ. Traumatic rupture of the thoracic aorta. Emerg Med Clin North Am 1991; 9:789-804. [PMID: 1915049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Because the diagnosis of a traumatic rupture of the aorta can be subtle, a high index of clinical suspicion must be maintained to arrive at a prompt and correct diagnosis. When chest radiography shows that the mediastinum is greater than 8 cm in width or that the arch or descending aorta are obscured, direct transfemoral arteriography remains the procedure of choice in hemodynamically stabilized patients. At the present time, computed tomography is not recommended as a definitive diagnostic modality.
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Shafer RW, Kim DS, Weiss JP, Quale JM. Extrapulmonary tuberculosis in patients with human immunodeficiency virus infection. Medicine (Baltimore) 1991; 70:384-97. [PMID: 1956280 DOI: 10.1097/00005792-199111000-00004] [Citation(s) in RCA: 192] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The annual number of cases of culture-proven extrapulmonary tuberculosis (TB) at our hospital increased from 47 cases in 1983 to 113 cases in 1988. At least 43% (199) of 464 consecutive patients with extrapulmonary TB during this 6-year period were infected with the human immunodeficiency virus (HIV); since HIV serologic testing was not performed routinely the true HIV prevalence is likely to be higher. Of the HIV-infected patients, 59% were intravenous drug users, 31% were Haitian, 3% were homosexual males, 1% were perinatally-infected infants, and 6% did not have a known risk factor for HIV infection. Ninety-eight percent of the HIV-infected patients were black (84%) or hispanic (14%). The HIV-infected patients were more likely than the control patients to have either disseminated, genitourinary, intra-abdominal, mediastinal, or concurrent pulmonary TB. Fever was nearly universal among the HIV-infected patients, but was absent in about one-third of the control patients. Among untreated HIV-infected patients, disease progression was rapid and nearly always fatal. Among HIV-infected patients who received treatment, the response to therapy, as judged by hospital survival and time to defervescence, was similar to that of the control patients. Despite the extensive tuberculous dissemination among the HIV-infected patients, the diagnosis of TB was difficult and often delayed. In addition to the decrease in tuberculin reactivity and the atypical chest radiograph patterns, there was a need to consider other HIV-related infections in the differential diagnosis. Although sputum specimens grew M. tuberculosis in greater than 90% of the HIV-infected patients in whom they were obtained, sputum AFB stains were positive in less than 50%. Blood and urine specimen cultures were positive in 56% and 77% of the HIV-infected patients in whom these specimens were obtained, but did not provide a means of early diagnosis. Cerebrospinal fluid and pleural fluid were abnormal in nearly all patients with involvement of these sites but were rarely AFB-positive and were, therefore, only suggestive of TB. Procedures such as biopsies and aspirates of peripheral lymph nodes, visceral lymph nodes, liver, and bone marrow provided the highest immediate diagnostic yields with rates between 50% and 90%. These procedures must be considered early in the course of illness in HIV-infected patients with suspected extrapulmonary TB due to the rapidly progressive nature of this often fatal but usually treatable infection.
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Siegelbaum MH, Weiss JP. Renal infarction secondary to fibrous dysplasia and aneurysm formation of renal artery. Urology 1990; 35:73-5. [PMID: 2296823 DOI: 10.1016/0090-4295(90)80019-j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We report a case of a previously healthy forty-year-old man with bilateral renal artery stenosis secondary to bilateral medial fibrous dysplasia. He was additionally found to have a dissecting aneurysm of the left upper renal artery branch with resultant infarction of the upper and middle pole renal segments. We believe renal infarction secondary to medial fibrous dysplasia with occlusion of the renal artery associated with a dissecting aneurysm has not been reported, and we report the first such case. A multimodality treatment approach was utilized.
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Abstract
Of 8 patients with symptoms of advanced cystitis due to pelvic radiation treated with hyperbaric oxygen 7 are persistently improved during followup. All 6 patients treated for gross hematuria requiring hospitalization have been free of symptoms for an average of 24 months (range 6 to 43 months). One patient treated for stress incontinence currently is dry despite little change in bladder capacity, implying salutary effect from hyperbaric oxygen on the sphincter mechanism. One patient with radiation-induced prostatitis failed to respond. This experience suggests that hyperbaric oxygen should be considered the primary treatment for patients with symptomatic radiation-induced hemorrhagic cystitis.
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Weiss JP. Embryogenesis of ureteral anomalies: a unifying theory. THE AUSTRALIAN AND NEW ZEALAND JOURNAL OF SURGERY 1988; 58:631-8. [PMID: 3178602 DOI: 10.1111/j.1445-2197.1988.tb07573.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Extensive gross, microscopic and clinical studies of various ureteral anomalies have enabled investigators to set forth theories regarding the aetiologies of these anomalies consistent with observed fact. Synthesis of these observations allows for a simplified classification of mega-ureter (primary obstructed, reflux and non-obstructed, non-reflux mega-ureters), ureterocele, duplex ureters and ectopic ureters based upon some combination of mesenchymal differentiation anomalies and location anomalies. A defect early in mesenchymal differentiation would be expected to result in panureteral disease. A defect later in development would result in a focal abnormality anywhere along the course of the ureter. Influence upon ureteral bud mesenchyme by local expansion factors in the bladder base may result in various types of ureterocele. Position of the ureteral orifice on the trigone or in Wolffian duct derivatives would occur in accordance with the Weigert-Meyer principle and would correlate with upper tract dysplasias. Thus, an attempt has been made to systematize and trace the origins of mega-ureter, ureterocele, duplex ureters and ectopic ureters to defects of differentiation of the basic mesoblastic cell in aberrant locations of the ureteral bud.
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Abstract
Penile condyloma acuminatum is a rare pediatric entity. We report on a 17-month-old boy with penile and urethral condyloma acuminatum. The presence of cervical dysplasia in a histological setting suggestive of condyloma in his mother supports congenital acquisition of the disease. Histological and histochemical evidence for a viral etiology of the disease in the mother and patient is presented.
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Weiss JP, Boland FP, Mori H, Gallagher M, Brereton H, Preate DL, Neville EC. Treatment of radiation-induced cystitis with hyperbaric oxygen. J Urol 1985; 134:352-4. [PMID: 4020991 DOI: 10.1016/s0022-5347(17)47166-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effects of hyperbaric oxygen on radiation cystitis have been documented in 3 patients with radiation-induced hemorrhagic cystitis refractory to conventional therapy. Cessation of gross hematuria and reversal of cystoscopic bladder changes were seen in response to a series of hyperbaric oxygen treatments of 2 atmosphere absolute pressure for 2 hours. To our knowledge this is the first report of cystoscopically documented healing of radiation-induced bladder injury.
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Weiss JP, Schlecker BA, Wein AJ, Hanno PM. Preservation of periprostatic autonomic nerves during total perineal prostatectomy by intrafascial dissection. Urology 1985; 26:160-3. [PMID: 4024406 DOI: 10.1016/0090-4295(85)90051-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A modification of Young's total perineal prostatectomy technique is described to prevent damage to the apical branches of the cavernous nerves. Based on anatomic relationships between investing prostatic fascial layers and the neurovascular bundle, emphasis is placed on division of the apical prostatic urethra between the anterolateral endopelvic fascia and Denonvilliers fascia (intrafascial dissection) in avoidance of the apical nerves. Vertical incision in the fused distal portion of Denonvilliers fascia is necessary to make this dissection atraumatic regarding the adjacent paraprostatic neurovascular bundle. Clinical application of this completely intrafascial prostatic dissection is exemplified. It is concluded that careful modification of Young's technique of total perineal prostatectomy may result in increased postoperative potency rates.
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Abstract
Although previously regarded as a rarity, 13 of the 20 published cases of single unilateral vaginal ectopic ureter have been reported within the last year. We have seen 4 cases of a single unilateral vaginal ectopic ureter within a 4-month interval. The relationship of vaginal ureteral ectopia to müllerian and mesonephric duct anomalies is discussed. If the ureteral bud originates laterally from the mesonephric duct then the ureter may retain its connection with the mesonephric duct while failing to connect to the bladder. This condition combined with persistence of the distal mesonephric (Gartner's) duct, which ruptures vaginally, accounts for vaginal ureteral ectopia and incontinence. The diagnostic studies for vaginal ureteral ectopia include excretory urography, radionuclide scanning, ultrasonography and administration of oral phenazopyridine in conjunction with careful vaginoscopic examination. The combination of lifelong wetting and solitary kidney on excretory urography should alert the urologist to this syndrome. The single unilateral vaginal ectopic ureter may be more common than has been suggested previously.
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Weiss JP, Wein AJ, Hanno PM. Sigmoidocystoplasty to augment bladder capacity. SURGERY, GYNECOLOGY & OBSTETRICS 1984; 159:377-80. [PMID: 6484795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Sigmoidocystoplasty with subtotal cystectomy was carried out in 14 patients with severe, symptomatic contracture of the bladder, refractory to other modes of therapy. Eight patients had excellent results, four showed improvement, two showed no improvement and required supravesical diversion. Indications for the procedures, complications and over-all results are discussed, with emphasis on our surgical technique. The possible advantages of sigmoidocystoplasty over ileal and ileocecal cystoplasty are noted.
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Weiss JP, Pollack HM, McCormick JF, Malloy TM, Hanno PM, Carpiniello VL. Renal hemangiopericytoma: surgical, radiological and pathological implications. J Urol 1984; 132:337-9. [PMID: 6737592 DOI: 10.1016/s0022-5347(17)49618-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The first case of renal hemangiopericytoma presenting radiologically as a hypovascular mass is described. Preoperative diagnostic evaluation included ultrasonography, retrograde pyeloureterography, computerized tomography and angiography. Electron microscopy is helpful to distinguish this lesion from histologically similar juxtaglomerular cell tumors. Although renal hemangiopericytoma may appear benign on pathological examination it should be treated as a low grade malignancy and followed carefully.
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Richman RA, Weiss JP, Hochberg Z, Florini JR. Regulation of growth hormone release: evidence against negative feedback in rat pituitary cells. Endocrinology 1981; 108:2287-92. [PMID: 6112137 DOI: 10.1210/endo-108-6-2287] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
To determine if the anterior pituitary gland is the site of negative feedback inhibition of GH release, we studied the effect of GH and multiplication-stimulating activity (MSA), a member of the somatomedin family, on isolated rat anterior pituitary cells in primary culture. The effect of GH was examined in two ways: 1) by adding to the cultures human GH (10 ng/ml to 20 microgram/ml) which was biologically active in the rat but not cross-reactive in the rat GH (rGH) RIA, and 2) by comparing rGH secretion in cultures of different cell densities. No suppression of either basal or prostaglandin E1-stimulated rGH release was found. An enhancement observed in serum-free conditions at high human GH concentrations was interpreted as a nonspecific response to protein, because bovine serum albumin produced the same effect. When added in the presence of serum, MSA (1--500 ng/ml) had no effect on rGH secretion. In the absence of serum, there were 71% and 30% increases in the basal and prostaglandin E1-stimulated rates of hormone release, respectively, possibly attributable to a trophic effect of MSA. Six other hormones having structural or functional similarity to either GH or somatomedin also failed to inhibit rGH secretion. Our results do not support the hypothesis that GH or somatomedin exerts a negative feedback effect on GH release directly on the anterior pituitary gland. Most likely, the hypothalamus or a higher brain center is the site for such regulation.
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Florini JR, Harned JA, Richman RA, Weiss JP. Effect of rat age on serum levels of growth hormone and somatomedins. Mech Ageing Dev 1981; 15:165-76. [PMID: 7194952 DOI: 10.1016/0047-6374(81)90072-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The somatomedins are a family of hormones which appear to mediate many of the anabolic actions of growth hormone; these processes often exhibit an age-associated deterioration in intact animals. We have demonstrated the validity of a radioreceptor assay for the determination of somatomedin levels in rat serum. In this assay, we measure displacement of 125I-labeled Multiplication Stimulating Activity (MSA) from receptors prepared from human placental membranes. Results with this procedure confirm and extend a previous report from this laboratory indicating a significant decrease in somatomedin levels during the latter part of the lifespan. Data are presented to eliminate possible artifactual explanations for the observed age-related changes. Furthermore, we find that the decrease in somatomedin levels can not be a simple result of an age-related decrease in basal levels of growth hormone in serum. We conclude that the decrease with age in circulating levels of the somatomedins is most probably attributable to a decrease in the activity of responsiveness of the tissues (most probably liver) which secrete somatomedins in response to stimulation by growth hormone.
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Richman RA, Weiss JP, Roberts SB, Florini JR. The effect of serum and multiplication stimulating activity on L6 myoblast growth: the lack of correlation with cyclic nucleotide changes. J Cell Physiol 1980; 103:63-9. [PMID: 6253507 DOI: 10.1002/jcp.1041030110] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The role of cAMP and cGMP in triggering proliferation of rat myoblasts was evaluated by: (1) measuring effects of mitogens on intracellular cyclic nucleotide levels, and (2) observing effects of agents which altered cyclic nucleotide levels on cell proliferation. Multiplication stimulating activity (MSA, 1 microgram/ml), a member of the somatomedin family, stimulated cell proliferation after 48 hr. It had little effect on cellular cyclic nucleotide levels, measured by radioimmunoassay. Horse serum (HS) and fetal bovine serum (FBS) stimulated cell proliferation approximately equally. Neither affected cAMP levels; FBS reduced cGMP to 33% of control values, but HS had no effect. Thus, there was no simple correlation between mitogenic action and cyclic nucleotide levels at any time from 5 min to 24 hr after addition of a purified mitogen or serum. Furthermore, agents which caused substantial changes in cyclic nucleotide levels had no effect on cell proliferation. Prostaglandin E1 (5 microM) elevated cAMP 440% without affecting cGMP levels or cell growth. A potent phosphodiesterase inhibitor, 1-methyl-3-isobutylxanthine (MIX, 0.1 mM), when added alone or in the presence of MSA, HS, or FBS, elevated cAMP 200% and cGMP 167%, but it had little effect on their mitogenic action. Lastly, a purified mitogen such as MSA, unlike serum, must be present for extended periods of time in order to stimulate cell proliferation. This makes it unlikely that a trigger mechanism functions in initiating cell division. We conclude that neither cAMP nor cGMP appear to be second messengers for the mitogenic action of MSA or serum on muscle cells.
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Cotter R, Rothenberg SP, Weiss JP. Dissociation of the intrinsic factor--vitamin B12 complex by bile: contributing factor to B12 malabsorption in pancreatic insufficiency. Scand J Gastroenterol 1979; 14:545-50. [PMID: 386477 DOI: 10.3109/00365527909181387] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Human bile incubated with vitamin B12 bound to intrinsic factor in human gastric juice will effectively dissociate this complex, and the vitamin will transfer to non-intrinsic factor unsaturated binding protein(s) contained in bile. Preincubation of the bile with pancreatic enzymes, particularly trypsin, and pepsin, decreases this effect of bile on the intrinsic factor--vitamin B12 complex by digesting the unsaturated binder(s) in the bile. These studies help explain why there is malabsorption of tracer amounts of vitamin B12 in some patients with pancreatic insufficiency, and why this abnormality is correctable by the administration of pancreatic extract.
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Rothenberg SP, Weiss JP, Cotter R. Formation of transcobalamin II--vitamin B12 complex by guinea-pig ileal mucosa in organ culture after in vivo incubation with intrinsic factor--vitamin B12. Br J Haematol 1978; 40:401-14. [PMID: 373791 DOI: 10.1111/j.1365-2141.1978.tb05812.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The in vivo incubation of intrinsic factor--[57Co]vitamin B12 in an ileal loop of a guinea-pig followed by in vitro culturing of segments of the ileum for 180 min has been used to study the transepithelial transport of vitamin B12. Analysis of the solubilized supernate of mucosa following the in vivo phase demonstrated that 44% of the [57Co]vitamin B12 was bound to intrinsic factor (IF), 26% was free, and 16% was bound to transcobalamin II (TCII). Following culture, similar analysis demonstrated that 18% of the vitamin was now bound to IF, 49% was free, and 35% ws bound to TCII. In the culture medium, 54% of the [57Co]vitamin B12 was free and 37% was bound to TCII. The formation of TCII-[57Co]vitamin B12 did not occur if homogenized mucosa was incubated with free[57Co]vitamin B12, but it did form in cultures of ileal segments from animals given an excess of unlabelled vitamin to saturate all circulating TCH, and in the medium containing puromycin. Indirect immunofluorescence using chicken anti-TCII demonstrated that TCII was associated with the mucosal cells of both the ileum and jejunum. These studies demonstrate that following transepithelial flux of vitamin B12 through the ileal mucosa, the vitamin becomes coupled to TCII. This coupling requires a structurally intact mucosa and the source of the TCII appears to be the ileal mucosal cell rather than unsaturated TCII circulating in the blood.
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Weiss JP, Barlow CH, Chance B. Pentobarbital-induced reduction of pyridine nucleotide measured by surface fluorometry in perfused rat heart. Biochem Pharmacol 1978; 27:1510-1. [PMID: 212073 DOI: 10.1016/0006-2952(78)90110-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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