Plasmapheresis: first year of experience at Humana Hospital-Alaska.

This report summarizes the first year of experience with therapeutic plasmapheresis at Human Hospital-Alaska. Eleven patients had plasmapheresis; 6 patients with the Guillain-Barré syndrome, and patients with thrombotic thrombocytopenic purpura (TTP), Eaton-Lambert syndrome, myasthenia gravis, post transfusion purpura, and multiple myeloma complicated by hyperviscosity and coagulopathy. Many of our patients appeared to benefit from plasmapheresis, but we also report a variety of complications. Our approach to establishing plasmapheresis in a community hospital setting is discussed.

Renovascular hypertension and demyelimating disease in a young woman.

Renal artery stenosis is an uncommon, but curable cause of systemic hypertension. The most common causes of stenosis are atherosclerosis, and fibromuscular dysplasia. Diagnosis may be difficult due to the lack of a suitable screening test, and a high index of suspicion needs to be maintained. Treatment may be with pharmacotherapy, renal angioplasty, or surgery and the choice of therapy needs to be tailored to the individual patient. Once a stenotic lesion is discovered in a hypertensive patient, the functional significance is not always clear cut. Fibromuscular dysplasia may be a systemic disease in some cases, and may affect the central nervous system.

Thrombotic thrombocytopenic purpura.

This case represents a classical presentation of severe TTP. At the time of diagnosis, the patient had a markedly depressed platelet count and evidence of severe hemolytic enemia. Her neurologic symptoms were not ominous at the time of initial presentation but may have worsened rapidly without treatment. She also demonstrates the success of current treatment modalities. A combination of plasma infusion followed by plasmapheresis, anti-platelet agents, corticosteroids, and vincristine was employed. As in most cases of TTP reviewed in the medical literature, it is difficult to sort out which treatment modality was most responsible for the improvement. Since this is such a deadly disease, there is a tendency to treat with a combination of agents in addition to plasmapheresis. Nonetheless, an impression remains that plasmapheresis was most closely associated with her recovery. As an additional comment, the use of plasmapheresis in this patient represented the first use of a pheresis machine that had been obtained in Anchorage, Alaska at the urging of the medical community. Our location, remote from academic centers, has made the use of technology such as plasmapheresis less accessible. The presence of plasmapheresis capabilities in a community setting such as ours raises many questions pertaining to the appropriateness of use of the technology, management of complications, etc.. We plan to carefully monitor these parameters.

Public Health Services Corps: a second opinion.

Numerous issues concerning the value of the Public Health Service Corps experience were raised in a recent article, "Why I Am Leaving a Rural Practice," by Paul A. Johnson, M.D. Because responses to tht essay were particularly pertinent to the future of group practice in rural America, Group Practice sought to offer another viewpoint by asking Richard L. Neubauer, M.D., to describe his PHSC experience.

Fractionation of DNA nucleotide transcripts from Moloney sarcoma virus and isolation of sarcoma virus-specific complementary DNA.

Radioactive DNA complementary to nucleotide sequences in Moloney murine sarcoma virus (MSV) and Moloney leukemia virus (M-MuLV) complex was made by the endogenous reverse transcriptase reaction. These virus stocks contained a threefold excess of MSV over M-MuLV as measured by biological assay. The complementary DNA was an accurate copy of the viral RNA in that 86% of 35S viral RNA hybridized with complementary (cDNA) DNA at a 1.5 to 1 cDNA-RNA molar ratio. The complementary DNA, of a 4-6S size, was fractionated by sequential absorptions with MulV and the feline leukemia virus pseudotype of MSV, [MSV(FeLV)] RNA. In this manner three sets of nucleotide sequences whichrepresent different portions of the MSV viral complex were obtained: a sarcoma virus-specific fraction (cDNAsarc) with sequences that had no homology to M-MuLV RNA but which hybridized to MSV (FeLV) RNA, a sarcoma-leukemia fraction (cDNA common) with sequences common to MSV as well as M-MuLV viral RNA, and a cDNAleuk representing those nucleotide sequences found only in M-MuLV. Hybridization of MSV-MuLV viral 35S RNA with a threefold molar excess of cDNA's revealed that approximately 20% was hybridized with cDNAsarc, whereas approximately 75% was hybridized with cDNAcommon. M-MuLV 35S RNA alone did not hybridize with cDNAsarc but did hybridize 40 and 50% with cDNAleuk and cDNAcommon, respectively. The cDNAsarc represents about 25% of the total MSV sequences, whereas the cDNAcommon represents the remainder of the MSV virus genome. Some cDNAcommon sequences were shared by two other sarcoma viruses and several distinctly different isolates of MulV. In contrast, the MSV "sarc" sequences had little or no homology with two other murine sarcoma virus isolates.

Elimination of the sarcoma genome from murine sarcoma virus transformed cat cells.

Cat cells transformed by Moloney murine sarcoma virus contain virus-specific sequences in their RNA and DNA. Cloned, spontaneous revertant cell lines derived from clones of these cells had no evidence of the sarcoma genome in the cell RNA or DNA as judged by RNA-complementary DNA or DNA-complementary DNA hybridizations. ?This is apparently the first report of loss of a transforming genome in a revertant cell line.