Conversion of differentiation inducer resistance to differentiation inducer sensitivity in erythroleukemia cells.

Hexamethylene bisacetamide (HMBA) is a potent inducer of differentiation of murine erythroleukemia cells (MELC). Commitment, the irreversible initiation of the program of terminal-cell differentiation, is first detected in HMBA-sensitive DS19-SC9 MELC in culture after 10 to 12 h of exposure to HMBA. Vincristine (VC)-resistant MELC derived from the DS19-SC9 MELC line display increased sensitivity to HMBA and become committed with little or no latent period. In the present study, we showed that the MELC line R1, which is resistant to HMBA-mediated differentiation, became sensitive to inducer if selected for a low level of VC resistance (less than 10 ng of VC per ml). Four independently derived VC-resistant cell lines from HMBA-resistant R1 cells, designated R1[VCR]a to R1[VCR]d, acquired sensitivity to HMBA and the accelerated kinetics of commitment that are characteristic of VC-resistant MELC derived from the parental DS19-SC9 cells. The calcium channel blocker verapamil suppresses the VC resistance of R1[VCR] cells but does not alter the accelerated response to HMBA. In R1[VCR] cells there was no detectable increase in the level of the 140-kilodalton P-glycoprotein. Transient inhibition of protein synthesis during the latent period delays inducer-mediated commitment of VC-sensitive DS19-SC9 MELC but does not alter the accelerated commitment kinetics of R1[VCR]a cells. Previously, we have reported evidence that protein kinase C beta (PKC beta) plays a role in HMBA-induced MELC differentiation and that compared with DS19-SC9 cells, R1 cells have a relatively low level and R1[VCR]a cells have a high level of PKC beta. These findings suggest that (i) acquisition of VC resistance overcomes the block acquired by R1 cells to HMBA-mediated differentiation; (ii) the accelerated kinetics of HMBA-induced commitment of VC-resistant MELC is not dependent on the verapamil-sensitive transport channel that is responsible, at least in part, for resistance to VC; (iii) in VC-resistant MELC, there is constitutive expression or accumulation of a protein required for HMBA-induced differentiation; and (iv) an elevated level of PKC beta activity may play a role in the altered response of R1[VCR] and other VC-resistant MELC to HMBA.

Protein kinase C mediates basic fibroblast growth factor protection of endothelial cells against radiation-induced apoptosis.

Basic fibroblast growth factor (bFGF) was found to protect bovine aortic endothelial cells against the lethal effects of ionizing radiation by inhibiting the programmed cell death (apoptosis) induced in these cells by radiation exposure. The involvement of the bFGF receptor tyrosine kinase in this function was demonstrated by abrogation of the radioprotective effect of bFGF by a specific inhibitor of the bFGF receptor tyrosine kinase, the tyrphostin AG213. The downstream signaling after stimulation of the bFGF receptor tyrosine kinase in bovine aortic endothelial cells involved translocation of the alpha isotype of cytoplasmic protein kinase C (PKC) into the membrane and its activation within 30 s after bFGF stimulation. The involvement of PKC in the radioprotective effect conferred by bFGF was suggested by the demonstration that nonspecific PKC activation by short-term exposure (30 min) to the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA; 30 ng/ml) mimicked the radioprotective effect of bFGF. Furthermore, treatment of the cells with the PKC inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (20 microM) abrogated the radioprotective effect of bFGF, as was observed after the depletion of cellular PKC by overnight preincubation with high-dose TPA (200 nM). Agarose gel electrophoresis of DNA extracted from irradiated bovine aortic endothelial cells showed that both TPA (30 ng/ml; 30 min) and bFGF (1 ng/ml) inhibited the apoptotic degradation of DNA induced in these cells by radiation exposure (500 cGy). Both the bFGF- and the TPA-mediated inhibition of apoptosis could be reversed by the PKC inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (20 microM). These data demonstrate the involvement of PKC in the inhibition of radiation-induced apoptosis by bFGF and the rescue of endothelial cells from this mode of radiation-induced cell death.

Expression of transforming growth factor alpha and epidermal growth factor receptor messenger RNA in neoplastic and nonneoplastic human kidney tissue.

Using Northern blot analysis, we have demonstrated that mRNA for transforming growth factor alpha (TGF-alpha) was expressed in five malignant kidney tissue specimens but was not detected in their autologous nonneoplastic homologues. In addition, the expression of epidermal growth factor (EGF) receptor mRNA in these malignant tissues was 2- to 3-fold greater than in nontransformed tissues. In two cases examined using immunohistochemistry, we were able to correlate the increased expression of the mRNA with an increase in protein expression. Since TGF-alpha is known to bind to the EGF receptor, the finding of an increased expression of both TGF-alpha and EGF receptor mRNA in kidney tumor tissue suggests that interaction between TGF-alpha and the EGF receptor may play a role in promoting transformation and/or proliferation of kidney neoplasms, perhaps by an autocrine mechanism.

Near drowning in the dead sea. Electrolyte imbalances and therapeutic implications.

Unusual serum electrolyte abnormalities developed in eight patients who nearly drowned (ND) in the Dead Sea. Elevations in serum calcium and magnesium levels in particular required specific therapeutic intervention. The Dead Sea has a uniquely high concentration of calcium, magnesium, sodium, potassium, and chloride. The unusual serum electrolyte elevation that was observed in the ND victims in the Dead Sea apparently reflected the large solute load to which they were exposed. Four patients died subsequent to ND. Near drowning in the Dead Sea therefore represents a clinical entity that is associated with a high fatality rate and in which unrecognized major electrolyte abnormalities, in addition to the known respiratory complications, may influence the outcome.

Right ventricular outflow tract obstruction due to extracardiac tumors. A report of three cases diagnosed and followed up by echocardiographic studies.

Echocardiography has become a valuable diagnostic tool in various clinical conditions. Its use for the detection of extracardiac tumors has seldom been reported. The majority of these descriptions are of single case reports. We have recently encountered three patients (two with lymphomas and one with seminoma) who presented with signs and symptoms suggestive of right ventricular outflow tract obstruction. Two-dimensional echocardiography enabled the prompt diagnosis of extracardiac tumors compressing the heart. Moreover, echocardiography proved to be an excellent noninvasive tool for assessing the success of therapy for mediastinal tumors.

Biology and treatment of multiple myeloma.

The uniformly fatal plasma cell malignancy, multiple myeloma (MM), currently represents 10-15% of hematologic neoplasms in the USA and has been steadily increasing in incidence for several decades. Therapeutic alternatives have lagged significantly behind insights into the biology and pathogenesis of this entity. Traditionally felt to be a neoplasm of fully differentiated plasma cells, evidence has been mounting that the self renewing population consist of cells derived from a much earlier compartment; perhaps prior to B-cell lineage commitment or even at the level of an earlier 'stem cell'. Bcl-2 protein overexpression has been almost uniformly seen in both clinical myeloma specimens as well as in myeloma cell lines. The failure to consistently identify the t(14;18) translocation, normally found in follicular lymphomas and characteristically associated with overexpression of bcl-2, implies a unique mechanism in MM. A number of cytokines, including TNF alpha, IL-1 and IL-6 have been found to play a central role not only in the biology of the malignant clone but also in the bony and other systemic manifestations of this disease. Since both IL-6 and bcl-2 protein have been shown to prevent programmed cell death, this may be the unifying event in MM. Standard therapy for MM has been an alkylating agent and corticosteroid. Combination chemotherapy provides more prompt palliation but no clear survival advantage. In advanced stages, adriamycin may offer some survival advantage. High dose chemotherapy with or without stem cell support offers a potentially curative therapeutic approach. New interventions directed at the complex cytokine networks pertinent to the pathogenesis of MM are an exciting new area of investigation. Identification of new prognostic parameters as well as new active agents remains the central theme in clinical myeloma research.

Bilateral optic neuropathy with IgGkappa multiple myeloma improved after myeloablative chemotherapy.

A 49-year-old woman with immunoglobulin GK multiple myeloma developed progressive visual loss with bilateral upper and lower central arcuate scotomas. Funduscopic and electrophysiologic studies indicated bilateral optic neuropathy. The immunoglobulin G fraction of the patient's serum reacted with retinal ganglionic cells in bovine retina. The visual abnormalities remitted after myeloablative chemotherapy and disappearance of the paraprotein.

Polymerase chain reaction detection of Kaposi's sarcoma-associated herpesvirus-optimized protocols and their application to myeloma.

Since its discovery in 1994, KSHV (also called human herpesvirus-8 or HHV8) has been implicated in a variety of disorders. Although the association of KSHV with Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease has been well established, its presence in some other diseases, such as multiple myeloma, remains controversial. Because most KSHV studies are based on polymerase chain reaction (PCR) analysis, the conflicting data may be attributable to variations in the methods, primer sets, and target sequences selected. To establish an efficient and reliable PCR approach for KSHV detection we designed eight sets of primers to six regions (ORFK1, ORFK2, ORFK9, ORK26, ORF72, and ORF74) of the KSHV genome using appropriate database and software. The detection sensitivity of these primers was carefully assessed and their reliability was strictly validated in a series of positive (15 KS and PEL samples) and negative (16 lymphoid tissues) controls. We found that primer sets to the ORFK9 region showed the highest sensitivity, whereas primer sets to ORFK1 and ORF74 showed the lowest sensitivity. Primer sets to ORFK9, ORF26 and ORF72 regions detected all of the positive cases, whereas other primer sets showed varying detection rates or nonspecific bands. All 16 negative controls were negative with all primer sets. However, six of 16 negative controls became positive when we used nested PCR targeting ORF26. Therefore, multiple target KSHV sequences increase the detection efficiency, while nested PCR protocols are likely to introduce false positivity. Using ORFK9, ORF26 and ORF72 primer sets, we screened bone marrow biopsies from 18 cases of multiple myeloma, and failed to detect any KSHV sequences. This finding supports the conclusion that KSHV is not associated with multiple myeloma. Indeed, our results further confirm that although KSHV is universally present in Kaposi's sarcoma and primary effusion lymphoma, it is not ubiquitious.

Technetium-99m-MIBI versus fluorine-18-FDG in diffuse multiple myeloma.

Experience of scintigraphic detection of bone lesion and active bone marrow involvement of multiple myeloma, especially with sestamibi and FDG-PET scans is in evolution. We report a case of intense sestamibi uptake in bone marrow correlating with the extent of the disease, while FDG-PET scans showed activity only in areas of active disease progression associated with pain. Technetium-99m-sestamibi appears to indicate the extent of the disease, while [18F]FDG-PET scans show sites of active tumor proliferation and may be useful in directing local therapy such as radiation.

Induction of differentiation of myeloid leukemic cells by busulphan: in vivo and in vitro observations.

Treatment of a 74 year old patient with chronic myelogenous leukemia (CML) with busulphan resulted in an abrupt and pronounced decrease of the white blood cell (WBC) count with restoration of normal peripheral blood cell morphology and regression of splenomegaly. The Philadelphia positive (Ph+) clone was however still detectable. The alterations in the WBC count and morphology were not preceded by marrow hypoplasia but correlated closely with a marked decrease in the serum levels of Transcobalamin I (TC I), a vitamin B12-binding protein derived from immature myeloid precursors and a reciprocal rise in serum TC III, a vitamin B12-binding protein originating from terminally differentiated mature granulocytes. Studies on the HL-60 cell line showed that busulphan is capable of inducing leukemic cells to differentiate into granulocyte-like cells. These observations, taken together, suggest that in addition to its potent myelosuppressive effects, busulphan may induce apparent clinical remissions in some CML patients by promoting terminal cell differentiation.

Excessive hepatitis-B surface antigen production after corticosteroids and the development of immunoblastic lymphoma.

The development of B-cell immunoblastic lymphoma in a 51 year old patient with hepatitis B virus related immune complex nephritis is described. The lymphoma was diagnosed eleven months after the administration of high dose corticosteroids which resulted in a striking increase in the HBsAg serum titer up to 1:1,000,000. This unusual association raises a number of interesting questions regarding the link between immune complex nephritis and immunoblastic lymphoma. The significance of corticosteroid therapy leading to excessive HBsAg secretion and the role played by this intense antigenic stimulation in the pathogenesis of lymphoma in this particular patient are also discussed.

Hepatic outflow obstruction and liver failure due to leukemic cell infiltration in chronic lymphocytic leukemia.

We report a patient with advanced progressive CLL who presented with liver failure and hepatic venus outflow obstruction (HVOD) due to lymphocytic leukemic infiltrates. Initiation of antileukemic therapy resulted in a rapid and prompt resolution of these life-threatening complications. This is apparently the first report of a CLL patient with HVOD and liver failure, attributable to liver infiltration by leukemic cells.

Acute abdomen due to granulocytic sarcoma of the terminal ileum.

A 57-year-old patient with chronic granulocytic leukemia in blast crisis and severe neutropenia is presented. This patient developed right sided peritonitis due to an isolated transmural granulocytic sarcoma of the terminal ileum. The affected segment was resected and the patient survived 4 more months. Thus, despite neutropenia, an aggressive surgical approach should be considered in a leukemic patient presenting with unexplained acute abdomen, since, as demonstrated here, a localized lesion which could not have otherwise been detected, was ultimately found and promptly resected.

Primary hyperparathyroidism presenting as cervical myelopathy.

Quadriplegia as a presenting syndrome in a case of primary hyperparathyroidism is reported. The clinical picture was misdiagnosed as a space-occupying lesion in the cervical spinal canal, for which an unnecessary laminectomy was performed. The neurologic deficits disappeared following the removal of a parathyroid adenoma. The neurologic presentations of hyperparathyroidism are reviewed and discussed.

Exacerbation of idiopathic pulmonary hemosiderosis in pregnancy.

Idiopathic pulmonary hemosiderosis (IPH) is a very rare disease in adults. Its occurrence in pregnancy has been described only once. A case of a 16-yr-old patient with an exacerbation of IPH during pregnancy resulting in intrauterine fetal death in the 28th week of gestation is described. The deterioration of the IPH is most probably related to the hemodynamic alterations which are at their maximum during the seventh month of pregnancy. Although rare, the case suggests that women with IPH should be followed carefully during pregnancy and, in the case of a deterioration in the patient's condition despite immunosuppressive therapy, termination of pregnancy should be considered.

Acute febrile neutrophilic dermatosis (Sweet's syndrome).

We describe a patient who displayed the classic features of acute febrile neutrophilic dermatosis (Sweet's syndrome): sudden onset of erythematous plaques, fever, arthritis, and characteristic histologic findings. Unusual findings in her case were the localization of the lesions mainly on the legs, absence of leukocytosis and preceding illness, and marked neutrophilic infiltration in the subcutis. In addition, the fever and eruption subsided on the day the results of pathologic examination were available, making any treatment unnecessary. The short course of the disease in this patient suggests the possibility of postponing steroid treatment for one week in all patients with acute febrile neutrophilic dermatosis.