The stimulation of fibroblasts' collagen synthesis by neoplastic cells is modulated by the extracellular matrix. Human fibroblasts cocultured with neoplastic MCF7 cells produce increased amounts of collagen. A maximal stimulation requires direct cell-cell contacts between tumor cells and fibroblasts. However, this effect could be reproduced, although to a lesser extent, by medium conditioned by MCF7 cells, suggesting that it is mediated by a factor produced by MCF7 cells and secreted, at least partly, under a soluble form (Noël et al., 1992). This Collagen Stimulating Factor ("COSF") present in the culture medium displayed a molecular mass between 3,500 to 10,000 daltons, bound to heparin and appeared to be different from the growth factors described until now. The "COSF" can be released from the surface of MCF7 cells by treatment with heparin. The aim of the present work was to investigate the influence of various extracellular matrix components on the production and the release of "COSF". A 3- to 4-fold enhancement of collagen synthesis was observed in coculture on plastic and collagen type I substrates without significant modification of the non-collagen proteins. The increased collagen synthesis was paralleled by an elevation of specific collagen mRNAs level suggesting a regulation at a pretranslational level. On the opposite, in the presence of soluble or insoluble laminin, this stimulation was abolished. Similarly, coculture on "reconstituted basement membrane matrix", matrigel, did not increase collagen production. The "COSF" was found to bind to matrigel and could be released from the basement membrane matrix by treatment with heparin.


Localization of the expression of type I, II, III collagen, and aggrecan core protein genes in developing human articular cartilage. The expression of mRNAs for collagen types I, II, III and for aggrecan core protein was studied in developing human femoral cartilage by in situ hybridization, with special attention given to the cartilage covered by the perichondrium and to the articular surface. In parallel, the synthesis of the related proteins was monitored by immunohistochemistry. The cells metabolically active for type I and type III collagen expression were identified by hybridization using [32P]-labeled cDNA clones coding for human alpha 1(I) and alpha 1(III), respectively. Type II collagen and core protein mRNAs were detected by hybridization with specific [32P]-labeled oligonucleotide probes. In the femoral heads of one 22-week old fetus and of one newborn, our in situ hybridization and immunohistochemical analysis revealed that chondrocytes located immediately subjacent to the perichondrium produced collagen types I, II, III as well as aggrecan; whereas only type II collagen and aggrecan gene expression was detected deeper in the cartilage covered by the perichondrium. This observation supports the hypothesis that the inner cell layers of perichondrium are chondrogenic, with a transient state where cells express all the markers studied here. At the articular surface different patterns of expression were observed at the two developmental stages. After 22 weeks of fetal development only collagen types I and III were expressed by the surface zone cells while in the newborn cartilage, these cells expressed all the molecules studied (collagen types I, II, III and cartilage proteoglycan). At both ages the underlying cartilage cells expressed only the cartilage-specific molecules (type II collagen and aggrecan). Thus a progressive transformation of cartilaginous matrix occurs with time from the deep cartilage up to the surface by addition of new components, i.e. aggrecan and type II collagen. These results supplemented by an immunofluorescence analysis on 20-, 26- and 38-week old fetal femoral heads suggest that expression of collagen and aggrecan in the cartilage covered by the perichondrium and in the cartilage at the articular surface are subject to different regulatory mechanisms during development. Furthermore, the appearance of hybridizable core protein and type II collagen mRNAs at the articular surface, closely followed by the appearance of the proteins for which they code, indicates that core protein and type II collagen expression is regulated primarily at the transcriptional level in this region. Finally, the similar topography observed for the expression of these two proteins suggests that the genes for these two major constituents of cartilage matrix are coordinately regulated during growth of articular cartilage.


Isolation and serine protease inhibitory activity of the 44-residue, C-terminal fragment of alpha 1-antitrypsin from human placenta. alpha 1-Antitrypsin (AAT) is a potent fluid-phase inhibitor of serine proteases. It forms a tightly bound, stoichiometric complex with these enzymes and is inactivated by cleavage within its reactive center. Evidence is here presented, that the 44-residue C-terminal fragment of AAT, termed SPAAT (short peptide from AAT), is found in human tissue, where it is apparently bound to the extracellular matrix (ECM). The identity of SPAAT was established by amino acid sequence analysis through its 40 N-terminal residues. Placental SPAAT inhibits chymotrypsin, human neutrophil elastase (HNE) and pancreatic elastase, but has no effect on trypsin. Unlike AAT, both placental and chemically-synthesized SPAAT are reversible, competitive inhibitors of chymotrypsin with Kl's of 0.92 and 7.5 microM, respectively. Both AAT and placental SPAAT also bind to diisopropyl fluorophosphate (DFP)-treated HNE as well as cathepsin G. SPAAT may therefore play an important role in the protection of ECM proteins, such as elastin, proteoglycans (PG) and/or collagen, from inappropriate attack by serine proteases.


Isolation and characterization of enzymes hydrolyzing chymotrypsin synthetic substrate (Enzyme I) and trypsin synthetic substrate (Enzyme II) from the envelope of Capnocytophaga gingivalis. Enzymes hydrolyzing chymotrypsin synthetic substrate and trypsin synthetic substrate, referred to as Enzyme I and Enzyme II, respectively, were found in the envelope fraction of Capnocytophaga gingivalis (ATCC 33624). Detergent extraction of both enzymes were purified by gel filtration, ion exchange chromatography, and affinity chromatography. The Enzyme I was a serine-containing metallo enzyme with a molecular mass of 77 kDa. The molecular mass of the Enzyme II was 83 kDa, and it was inhibited by tosyl-L-lysine chloromethyl ketone and leupeptin, and thus may be related to trypsin.


Genetic polymorphism of the gene encoding the outer surface protein A (OspA) of Borrelia burgdorferi. The genes coding for the outer surface protein (OspA) of Borrelia burgdorferi, the causative agent of Lyme borreliosis have been cloned and sequenced. Two German strains (skin isolate PKo and cerebrospinal fluid isolate PBi) have been analyzed. Using an OspA-specific monoclonal antibody (L32 2E7) for immunological screening of a genomic pUC18 library of B. burgdorferi strain PKo, and OspA-producing clone was detected and subclones containing the open reading frame were constructed. The gene coding for the OspA protein of B. burgdorferi strain PBi was amplified using polymerase chain reaction (PCR) and cloned in pUC8. The open reading frame of both ospA genes consists of 822 nucleotides corresponding to a protein of 273 amino acids. Both proteins have a calculated molecular mass of 29.6 kDa. Molecular analysis revealed significant differences between each other and to already-published sequences of ospA of B. burgdorferi strains B31, ZS7 and N40 (the ospA genes of B31, ZS7 and N40 are nearly identical). The deduced amino acid sequences of the OspA protein of strains PKo and PBi showed a homology of 83% to each other and 77% and 80%, respectively, to OspA protein of strain B31. The three proteins contain a variable middle region, whereas the N and the C terminus are conserved. This unexpected high dissimilarity of the ospA genes may be important in respect to vaccination studies and diagnostic procedures (i.e., development of PCR primers or serodiagnostic antigens). Moreover, the molecular heterogeneity of OspA confirms three out of seven immunologically defined OspA serotypes of a recently proposed OspA serotyping system.


Sero-diagnosis of tuberculosis with A60 antigen enzyme-linked immunosorbent assay: failure in HIV-infected individuals in Ghana. In order to assess the diagnostic usefulness of the A60 (ANDA Biological, Strassbourg, France) sero-diagnostic enzyme-linked immunosorbent assay (ELISA) kit for tuberculosis in Africa, sera of 53 pulmonary smear-positive tuberculosis (TB) patients, 30 apparently healthy control subjects and 6 AIDS suspects were sampled in Agogo Hospital in the forest area of Ghana. These sera were analyzed for antibodies to HIV-1 and HIV-2, and IgG-antibodies to the A60 BCG-antigen, while the non-HIV individuals were tested for total IgG levels. One healthy control subject, all of 6 AIDS suspects and 7 of the TB patients has HIV infections. In the non-HIV TB group, the sensitivity and specifity of the A60 ELISA was 78% and 86%, respectively, which was much poorer than expected from published reports about the A60 test. The A60 test failed, completely however, to discriminate between TB and non-TB in the HIV-positive group. In the non-HIV groups, total IgG levels were significantly higher in TB patients than in controls. It seems that the usefulness of the A60 ELISA test to diagnose tuberculosis is very limited in this high-incidence area, and that it seems to be of no value in patients infected with HIV.


Antibacterial effect of bovine milk antibody against Escherichia coli in a mouse indigenous infection model. A skim-milk fraction and a whey-protein concentrate (WPC) fraction were prepared from the cows that had been immunized with E. coli isolated from the mouse intestine. The antibacterial effect of these fractions against E. coli was examined. They contained antibody with a high affinity for E. coli strain 48, a representative strain in the mouse intestine, which is composed of a large amount of IgG and smaller amounts of IgA and IgM. Although these fractions showed no bactericidal or bacteriostatic activity against E. coli 48 directly in vitro, they exhibited strong agglutination and opsonization activities against the bacteria in vitro. The bacteria opsonized with the WPC fraction were taken up more effectively by liver macrophages in vivo, compared with unopsonized E. coli, after an intravenous injection into mice. Oral administration of the skim-milk fraction to mice significantly reduced the susceptibility to the lethal toxicity of 5-fluorouracil (5 FU). The increase in the population levels of E. coli in the intestinal tract after administration of 5 FU was inhibited by oral administration of the skim-milk fraction. These results strongly suggest that specific antibody may be effective in the prophylaxis against the indigenous infection with gram-negative bacteria such as E. coli after a period of chemotherapy in cancer patients.


Helping victims of violence in Uganda.

Helping victims of violence in Uganda. We report on a project to assist victims of war and violence in Uganda. The original aim of this project, set up by the Medical Foundation for the Care of Victims of Torture, was to establish a centre for the assessment and treatment of torture victims who had suffered during previous regimes in that country. We found, however, that a specialist centre was not the most appropriate response in a country like Uganda. We argue for the need to respect local initiatives and systems of support and against the notion that there is a single model of care which is universally relevant. Following much investigation and involvement with local personnel, we have developed a programme of training and discussion for health workers, and a service to reach the many women who have suffered rape, and whose suffering has continued, largely ignored.


Adaptation after torture: some thoughts on the long-term effects of surviving a repressive regime. The long-term problems of refugee survivors of organized violence are considered. A case example is described in order to illustrate the complexity of factors that contribute to the psychological well-being and social adaptation of such a survivor. The limitations of the classic diagnostic approaches are discussed. It is suggested that measures of social function can be more helpful than a description of symptoms, and should be included in the concept of PTSD, in order to increase the usefulness of this diagnosis in relation to severe and chronic trauma.


[Radioimmunoscintigraphy of colorectal tumors with 99m-Tc marked CEA antibodies. Indications and clinical value]. In Germany, radioimmunoscintigraphy (RIS) (scintigraphic, specific imaging of benign and malignant diseases by radioactively labelled monoclonal antibodies) has been employed since 1985 in clinical trials involving patients with colorectal cancer. After proving successful for identifying primary tumors, RIS is now increasingly being used for the early diagnosis of recurrent and metastatic lesions. In this prospective study involving 75 patients with colorectal tumors confirmed by endoscopy and biopsy, it was shown that RIS using the SPECT technique with 99m-Tc-labelled monoclonal CEA antibodies has a sensitivity of 78% in the detection of local recurrent disease in cases in which diagnostic work-up has been inconclusive.


[Perforation of gastroduodenal ulcer: a risk analysis]. In 90 patients who, between 1.1.1986 and 31.12.1991, underwent surgery for a perforated gastric/duodenal ulcer, the importance of age, sex, ulcer history, ulcer site, free/covered perforation, extent of peritonitis, duration of history and the pre-operative risk assessment (ASA classification) was analysed with respect to the risk of dying of the perforated ulcer. The univariate analysis showed the following to be prognostically relevant factors: time interval between onset of acute symptoms and surgery (less than or equal to 24 hours: mortality rate 12%, greater than 24 hours: mortality rate 21%; p = 0.006); physical status of the patient as reflected in the ASA category prior to surgery (mortality: ASA II 0%, ASA III 8%, ASA IV 32%; p = 0.009), and the presence of a spontaneous pneumoperitoneum (free perforation 21% mortality, covered perforation 5% mortality; p = 0.049). Investigation of the overall influence of the univariate relevant factors in the logistic model showed a relative risk of 4.9 for duration of history, and of 5.4 for the ASA classification. The mortality risk for a patient who is operated on more than 24 hours after onset of the acute symptoms is 4.9 times that of a patient operated on within 24 hours. In the ASA classification, the mortality risk increases by 5.4 from one category to the next higher one.


The nuclear issue in Swedish schools.

The nuclear issue in Swedish schools. Sweden is almost unique in that its government through its foreign office gave financial support to a carefully thought out proposal from Svenska Läkare Mot Kärnvapen (Swedish Physicians against Nuclear Weapons) for a youth education project on the nuclear issue. The Swedish Board of Education has agreed to provide: 1. In-service training for teachers on current affairs; 2. Up-to-date teaching resources and materials, such as the booklet, Facts and Reflections on Nuclear Weapons; 3. A curriculum stating that education on nuclear and other environment issues should not be a special subject but should be involved in many school activities-for example the learning of foreign languages, biology, physics, science and even physical education. The Board's recommendations have been sent to every Swedish school, together with the booklet, but each school decides for itself whether or not to implement them. However, some teachers do some education on the nuclear issue in most Swedish schools.


Effects of prolonged war and repression on a country's health status and medical services: some evidence from Iran 1979-90. The decade following the Islamic revolution in Iran is surveyed from the point of view of the various ways in which the repressive policies of the new regime and, from September 1980, the war with Iraq affected health professionals, medical education and publishing, health services and living conditions. Sources consulted include publications from inside and outside the country, by apologists for and opponents of the regime, and a variety of commentators. Topics studied in more detail are the campaign against drug abuse, the cultural revolution in the universities, the country's leading English-language medical journal, wartime conditions, and the society in the aftermath of the conflict. As well as predating and outlasting the war, the unfavourable climate of repression is seen to have exacerbated its effects in many ways. The population has displayed considerable resilience in the face of overwhelming odds, but the overall picture cannot give much grounds for optimism with regard to either their physical or mental well-being in the future. Particular cause for concern is the profound damage and prolonged neglect sustained by the most basic preconditions for health and medical care.


[Refractory anemia with 5q--anomaly. Clinical picture and follow-up of seven patients]. The clinical picture and the course of the disease of seven patients with the 5q-syndrome are described. Examination of peripheral blood revealed refractory anaemia with macrocytosis, anisocytosis, poikilocytosis of erythrocytes, and platelet anisocytosis with some giant platelets. Characteristic bone marrow findings are megaloblastic dyserythropoiesis and micromegakaryocytes with hypolobulated nuclei. Cytogenetically, an interstitial deletion of the long arm of chromosome 5 is always found, associated with a haploid loss of the genes for the growth factors GM-CSF, M-CSF and IL-3. The disease is usually chronic, and only in the case of clonal evolution is there a considerable risk of leukemic transformation occurring. In the chronic phase, infusion of packed red cells as required individually has proved a reliable form of treatment. The results of chemotherapy have disappointed both in the chronic and acute phases of the disease.


Biological effects of low frequency electromagnetic fields. Epidemiological studies since 1979 have raised some medical and much public concern that low frequency electromagnetic fields, such as those of power-lines and in domestic and industrial electrical wiring, may have harmful biological effects. These studies are generally inconsistent, inconclusive, and difficult to replicate. Identifying biological mechanisms by which such harmful effects may occur has proved difficult, although there are several new and promising approaches. In epidemiological and laboratory studies much greater co-ordination and standardization is needed if greater scientific knowledge of these phenomena, as opposed to mere diverse speculation, is to be achieved.


[Hickman catheter for long-term parenteral therapy. A prospective interdisciplinary study]. 160 patients with a median age of 38 years (range two months to 84 years) having silicone rubber central venous access catheters for long-term parenteral nutrition or chemotherapy were studied prospectively. Two different types of catheters were used, the Broviac-type "life-cath" and the Groshong -catheter. Intraoperative complications were not noticed. Parenteral therapy was performed in 124 patients (81%) without any complications. After a mean postoperative interval of 36 weeks there were 34 catheters removed because of end of therapy. 78 patients died with the catheter in place. 40 catheters had to be removed before end of therapy due to catheter-related complications. Occlusion of the lumen occurred in nine patients after an interval from three to 20 weeks. Explantation of catheters due to a suspected catheter-related sepsis was performed in 17 patients. Both types of catheter showed a high cumulative patency rate of 90% after a twelve months period. However, there were catheters that had to be removed before planned end of therapy. Thus, the cumulative rate of functioning catheters is lower (44% of all catheters).


Health services in Vietnam.

Health services in Vietnam. This paper reviews the existing health services in Vietnam against the background of 50 years of wars with Japan, France, the United States and neighbouring countries, leaving a devastated economy and thousands of war-wounded, prostitutes, drug addicts and orphans. Defoliation has affected soil fertility and caused miscarriages, stillbirths and deformities. Unexploded bombs still blow off peasants' legs. The prevalence of malaria is increased by the many bomb craters where mosquitoes breed in stagnant water. Superstitions in some ethnic groups contribute to childhood malnutrition. A system is being developed of large provincial hospitals, 100-bed district hospitals and village clinics, incorporating traditional medicine. These are well staffed but poorly equipped. Modern medical and surgical equipment and medicines are urgently needed, but will have to be provided by humanitarian aid until trade links are restored.


[Clinical diagnosis and neuropathologic examination findings in 20 AIDS patients]. Disorders of the central nervous system (CNS) associated with HIV infections are becoming increasingly important in the area of clinical diagnosis and treatment of patients with AIDS. The aim of this retrospective analysis of 20 patients with AIDS who died in 1989 was to compare clinical diagnosis, neuroradiological findings and treatment with the results of neuropathological studies. The neuropathological examinations revealed primary CNS lymphoma (high-grade non-Hodgkin's lymphoma) in seven cases, cerebral toxoplasmosis in four cases, haemorrhagic infarction in three cases, cerebral cryptococcosis in three cases, and one case each of infiltration of the dura by a peripheral Burkitt's lymphoma, cytomegalovirus encephalitis and bacterial meningitis. A remarkably high percentage of CNS lymphomas with no distinct clinical or neuroradiological differentiation criteria were found in this study. On the basis of these data, we conclude that stereotactic biopsy and histological diagnosis should be recommended for patients with focal intracerebral lesions who fail to respond to suitable anti-parasitic treatment.


[Long lasting normalization of uric acid after combination therapy with 300 mg allopurinol and 60 mg benzbromarone in patients with gout and hyperuricemia]. Lasting normalisation of uric acid levels after treatment of patients with gout and hyperuricaemia with a combination of 300 mg allopurinol and 60 mg benzbromarone A total of 210 patients (163 men, 47 women) with gout and hyperuricaemia was treated for three months with daily doses of 300 mg allopurinol and 60 mg benzbromarone. During the course of treatment, the uric acid levels decreased to 4.3 +/- 1.3 mg/dl in male, and 4.4 +/- 1.3 mg/dl in female patients. Both of these levels differ significantly from the initial levels (p less than 0.001). Three months after discontinuation of treatment, uric acid levels were 5.7 +/- 1.2 mg/dl in women, and 5.9 +/- 1.4 mg/dl in men, levels that again differed significantly from the initial levels (p less than 0.001); both levels were, however, within the therapeutic range of below 6.4 mg/dl.


Mechanism of action of regulatory proteins encoded by complex retroviruses. Complex retroviruses are distinguished by their ability to control the expression of their gene products through the action of virally encoded regulatory proteins. These viral gene products modulate both the quantity and the quality of viral gene expression through regulation at both the transcriptional and posttranscriptional levels. The most intensely studied retroviral regulatory proteins, termed Tat and Rev, are encoded by the prototypic complex retrovirus human immunodeficiency virus type 1. However, considerable information also exists on regulatory proteins encoded by human T-cell leukemia virus type I, as well as several other human and animal complex retroviruses. In general, these data demonstrate that retrovirally encoded transcriptional trans-activators can exert a similar effect by several very different mechanisms. In contrast, posttranscriptional regulation of retroviral gene expression appears to occur via a single pathway that is probably dependent on the recruitment of a highly conserved cellular cofactor. These two shared regulatory pathways are proposed to be critical to the ability of complex retroviruses to establish chronic infections in the face of an ongoing host immune response.


Agents that increase the permeability of the outer membrane. The outer membrane of gram-negative bacteria provides the cell with an effective permeability barrier against external noxious agents, including antibiotics, but is itself a target for antibacterial agents such as polycations and chelators. Both groups of agents weaken the molecular interactions of the lipopolysaccharide constituent of the outer membrane. Various polycations are able, at least under certain conditions, to bind to the anionic sites of lipopolysaccharide. Many of these disorganize and cross the outer membrane and render it permeable to drugs which permeate the intact membrane very poorly. These polycations include polymyxins and their derivatives, protamine, polymers of basic amino acids, compound 48/80, insect cecropins, reptilian magainins, various cationic leukocyte peptides (defensins, bactenecins, bactericidal/permeability-increasing protein, and others), aminoglycosides, and many more. However, the cationic character is not the sole determinant required for the permeabilizing activity, and therefore some of the agents are much more effective permeabilizers than others. They are useful tools in studies in which the poor permeability of the outer membrane poses problems. Some of them undoubtedly have a role as natural antibiotic substances, and they or their derivatives might have some potential as pharmaceutical agents in antibacterial therapy as well. Also, chelators (such as EDTA, nitrilotriacetic acid, and sodium hexametaphosphate), which disintegrate the outer membrane by removing Mg2+ and Ca2+, are effective and valuable permeabilizers.


Editing of errors in selection of amino acids for protein synthesis. All living cells must conduct protein synthesis with a high degree of accuracy maintained in the transmission and flow of information from gene to finished protein product. One crucial "quality control" point in maintaining a high level of accuracy is the selectivity by which aminoacyl-tRNA synthetases furnish correctly activated amino acids, attached to tRNA species, as the building blocks for growing protein chains. During selection of amino acids, synthetases very often have to distinguish the cognate substrate from a homolog having just one fewer methyl group in its structure. The binding energy of a methyl group is estimated to contribute only a factor of 100 to the specificity of binding, yet synthetases distinguish such closely related amino acids with a discrimination factor of 10,000 to 100,000. Examples of this include methionine versus homocysteine, isoleucine versus valine, alanine versus glycine, and threonine versus serine. Many investigators have demonstrated in vitro the ability of certain aminoacyl-tRNA synthetases to edit, that is, correct or prevent incorrect attachment of amino acids to tRNA molecules. Several major editing pathways are now established from in vitro data. Further, at least some aminoacyl-tRNA synthetases have recently been shown to carry out the editing function in vivo. Editing has been demonstrated to occur in both Escherichia coli and Saccharomyces cerevisiae. Significant energy is expended by the cell for editing of misactivated amino acids, which can be reflected in the growth rate. Because of this, cellular levels of aminoacyl-tRNA synthetases, as well as amino acid biosynthetic pathways which yield competing substrates for protein synthesis, must be carefully regulated to prevent excessive editing. High-level expression of recombinant proteins imposes a strain on the biosynthetic capacity of the cell which frequently results in misincorporation of abnormal or wrong amino acids owing in part to limited editing by synthetases. Unbalanced amino acid pools associated with some genetic disorders in humans may also lead to errors in tRNA aminoacylation. The availability of X-ray crystallographic structures of some synthetases, combined with site-directed mutagenesis, allows insights into molecular details of the extraordinary selectivity of synthetases, including the editing function.


Cost containment and new priorities in the European community. This article reports on the author's survey of the cost-control measures for health care in 12 European countries during the period from 1983 to 1990. Among these countries the greatest convergence was in the use of the budget as a system of control, reinforced by manpower controls. Budgets were constructed to restrict hospital costs and payments to doctors practicing outside of hospitals. Another strategy was cost sharing for purchase of drugs and, in some cases, for dentistry. Most countries took steps to control expensive medical equipment; others, to restrict entry to medical schools. The European experience demonstrates the technical feasibility of the government's controlling health care costs by regulating supply rather than demand. The key to Europe's success in the use of monopsony power, whereby one purchaser dominates the market. The author contends that regulation works in Europe and questions whether the United States can exert similar control over its coalition of insurers and providers in order to rein in its health care expenses.


Microbial reductive dehalogenation.

Microbial reductive dehalogenation. A wide variety of compounds can be biodegraded via reductive removal of halogen substituents. This process can degrade toxic pollutants, some of which are not known to be biodegraded by any other means. Reductive dehalogenation of aromatic compounds has been found primarily in undefined, syntrophic anaerobic communities. We discuss ecological and physiological principles which appear to be important in these communities and evaluate how widely applicable these principles are. Anaerobic communities that catalyze reductive dehalogenation appear to differ in many respects. A large number of pure cultures which catalyze reductive dehalogenation of aliphatic compounds are known, in contrast to only a few organisms which catalyze reductive dehalogenation of aromatic compounds. Desulfomonile tiedjei DCB-1 is an anaerobe which dehalogenates aromatic compounds and is physiologically and morphologically unusual in a number of respects, including the ability to exploit reductive dehalogenation for energy metabolism. When possible, we use D. tiedjei as a model to understand dehalogenating organisms in the above-mentioned undefined systems. Aerobes use reductive dehalogenation for substrates which are resistant to known mechanisms of oxidative attack. Reductive dehalogenation, especially of aliphatic compounds, has recently been found in cell-free systems. These systems give us an insight into how and why microorganisms catalyze this activity. In some cases transition metal complexes serve as catalysts, whereas in other cases, particularly with aromatic substrates, the catalysts appear to be enzymes.


Observations on "Cost containment and new priorities in the European community" by Brian Abel-Smith. A commentary on the article by Brian Abel-Smith briefly explores why the United States lags behind Europe in controlling health care costs. Three important factors are, first, that until recently the real cost of health insurance was not apparent to U.S. workers and political leaders; second, Americans prefer to try competition before resorting to other strategies; and third, responsibility for financing health care is divided among a large number of independent entities, while government regulation is split between the state and federal levels. At the same time, governments and private insurers in the United States have developed new health delivery structures and reimbursement mechanisms that the Europeans may find useful. A convergence of the two systems would be to the benefit of both.


Issues regarding health plan payments under Medicare and recommendations for reform. The failures of the market for current Medicare health plans include poor information and price distortions and can be attributed to government policy. Reforms that could improve its structure are annual open enrollment periods, premium rebates from health management organizations (HMOs) to members, and termination of the federal government's subsidy of Medicare supplementary insurance. However, the price for a basic Medicare benefits package would still be distorted because Medicare bases its contribution on the cost of a comparable package in the fee-for-service (FFS) sector rather than on the cost of the most efficient plan available to beneficiaries in each market area. The present Medicare HMO program almost certainly increases total Medicare costs and actually discourages HMO growth by shielding beneficiaries from the true price difference between basic benefits in the HMO and FFS sectors. Lacking payment reforms, the Medicare HMO program should be terminated.


Bacteriophage lysis: mechanism and regulation. Bacteriophage lysis involves at least two fundamentally different strategies. Most phages elaborate at least two proteins, one of which is a murein hydrolase, or lysin, and the other is a membrane protein, which is given the designation holin in this review. The function of the holin is to create a lesion in the cytoplasmic membrane through which the murein hydrolase passes to gain access to the murein layer. This is necessary because phage-encoded lysins never have secretory signal sequences and are thus incapable of unassisted escape from the cytoplasm. The holins, whose prototype is the lambda S protein, share a common organization in terms of the arrangement of charged and hydrophobic residues, and they may all contain at least two transmembrane helical domains. The available evidence suggests that holins oligomerize to form nonspecific holes and that this hole-forming step is the regulated step in phage lysis. The correct scheduling of the lysis event is as much an essential feature of holin function as is the hole formation itself. In the second strategy of lysis, used by the small single-stranded DNA phage phi X174 and the single-stranded RNA phage MS2, no murein hydrolase activity is synthesized. Instead, there is a single species of small membrane protein, unlike the holins in primary structure, which somehow causes disruption of the envelope. These lysis proteins function by activation of cellular autolysins. A host locus is required for the lytic function of the phi X174 lysis gene E.


Case mix adjusted nursing-home reimbursement: a critical review of the evidence. Nursing-home case mix adjusted payment systems typically base payments on estimates of patients' care needs, but to date the data on their effectiveness are ambiguous. Studies mainly show that access for patients most in need of care appears to improve under these systems. Case mix based payment systems have both positive and negative effects on quality of care and require compensating mechanisms for the potentially harmful incentives they can generate. On the positive side, nursing homes are paid more equitably; the negative aspect is reflected in higher costs, particularly for administration. A Health Care Financing Administration (HCFA) demonstration project may provide insights, but its limited number of predominantly small, rural, participating states, its tandem quality assurance system, and potentially confounding market variables may restrict the value of this project. We do not yet have the data to assess the impact of instituting case mix adjustment systems.


Expanding the definition of disability: implications for planning, policy, and research. Disability remains an area that is difficult to define and measure. Rheumatoid arthritis (RA), with its greater impact on women than on men, is one example of this. People with RA are limited in many areas besides paid work, so to measure this disability only in terms of paid work greatly underestimates its impact on people's lives, particularly those of women. This article reviews the major definitions of disability and reports the results of a national study assessing disability in both family and paid work roles. Both areas reveal high rates of disability among RA patients. The study concludes that measuring disability only in terms of paid work seriously underestimates its prevalence among women. These results have important implications for health policy because the greatest needs of the disabled may be, not in income replacement programs, such as Social Security disability programs, but rather in fortifying family and other care services that would enable people with RA to maintain higher levels of function in all domains of life.


Supporting the elderly: workplace programs for employed caregivers. An aging population and extended longevity are increasing the number of older people needing informal and family support. At the same time, women, the traditional caregivers, have entered the work force in record numbers. Consequently, concerns about how to care for dependent family members have become workplace issues. In response to the needs of employees who care for family members, employers have produced an array of policies, benefits, and programs, including flexible work schedules and information and referral services. Although these programs are a valuable complement to community services and government initiatives, relatively few employers have recognized the potential effects of caregiving on absenteeism, productivity, and turnover; even fewer have responded with workplace programs directed to the needs of their caregiving employees. To fill the gap, the government is considering mandating employee benefits, such as leave time for family illness. Community services are increasingly being directed to the needs of older people and their caregivers.


World blindness and the medical profession: conflicting medical cultures and the ethical dilemmas of helping. This is an account of a thwarted humanitarian effort and the strategic and ethical issues that is raised. Between 14 and 17 million people in the world are blind with cataract, a condition readily corrected by surgery. In 1989 a proposal was developed to attack this problem by supplying volunteer ophthalmologists to the world's leading private voluntary organizations that carry out programs in less developed countries. The proposal was rejected. This article describes the proposal and the issues on which it foundered: cost effectiveness, appropriate technology, changing ideologies of assistance, and conflict between the cultures of medicine and public health. The account illustrates the far-flung consequences of technological change in medicine, as well as the practical and ethical questions facing organizations that carry out overseas assistance programs.


Elevated lead burden in Chinese patients without occupational lead exposure. Studies were conducted in 10 healthy Chinese controls, 10 patients with chronic renal failure without gout, 8 patients with gout complicated with chronic renal failure and in 6 patients with chronic renal failure who subsequently developed gout. All the subjects had no history of occupational or accidental lead exposure. Total body lead burden was assessed by 24-hour urine collection measurements over a 72-hour period after intravenous administration of 1 g of calcium disodium EDTA. The postinfusion urinary lead excretion of the healthy controls (90.2, range 57.2-161.5 micrograms/3 days/1.73 m2) was higher than the values recently reported for healthy German controls. Similar to earlier studies, we failed to find elevated urinary lead excretion in patients with chronic renal failure without gout. Nevertheless, the EDTA mobilization test identified 2 patients with occult plumbism in this group of patients. Our study also clearly demonstrated that 4 of 6 patients with renal failure who developed gout de novo had underlying plumbism. The high prevalence of increased lead body burden in patients with chronic renal failure, in particular those associated with gout, indicates that lead may contribute to a significant portion of chronic renal disease in our patients. In addition, our data suggest that chronic low-level environmental lead exposure may subtly affect renal function.


Induction of intestinal mucosal atrophy by difluoromethylornithine: a nonuremic model of enhanced aluminum absorption. The intestinal absorption of aluminum (Al) appears to be enhanced in the uremic rat. Since atrophic changes of the intestinal mucosa have been observed in uremia the present study investigated whether intestinal atrophy induced by difluoromethylornithine (DFMO), a specific inhibitor of ornithine decarboxylase, could affect the absorption of Al. DFMO supplied with the drinking water (5%) to rats with normal renal function for 9 days resulted in a reduced number of microvilli with definite morphological alterations in small intestinal mucosa. Following an oral load of Al urinary excretion rates and 1-hour postload serum concentrations of Al were increased in DFMO-treated rats as compared to controls suggesting enhanced absorption of Al. Pattern and degree of urinary Al excretion as well as ultrastructural alterations of the intestinal mucosa were similar in DFMO-treated rats and uremic rats. The model of DFMO-induced intestinal alterations suggests that structural lesions of the intestine may be involved in the enhanced absorption of Al in uremia.


Combined acute hypoxemia and hypercapnic acidosis increases atrial natriuretic polypeptide in conscious dogs. To evaluate the changes in atrial natriuretic polypeptide during acute hypoxemia and acute hypercapnic acidosis, conscious mongrel dogs with controlled sodium intake were evaluated in four protocols: (1) 80 min of acute hypoxemia (PaO2 = 34 +/- 1 mm Hg) followed by 40 min of combined hypoxemia and hypercapnic acidosis (PaO2 = 38 +/- 1 mm Hg, PaCO2 = 60 +/- 3 mm Hg, pH = 7.15 +/- 0.03) (n = 7); (2) 40 min of combined acute hypoxemia and hypercapnic acidosis (PaO2 = 36 +/- 1 mm Hg, PaCO2 = 56 +/- 2 mm Hg, pH = 7.20 +/- 0.03) induced immediately following control measurements (n = 5); (3) 120 min of acute hypercapnic acidosis (PaCO2 = 58 +/- 1 mm Hg, pH = 7.20 +/- 0.01) (n = 5), and (4) 120 min of normoxemia and normocapnia (n = 7). These studies did not observe any association between urinary sodium excretion and circulating atrial natriuretic polypeptide during acute blood gas derangements in conscious dogs. The natriuresis with acute hypoxemia or acute hypercapnic acidosis was unaccompanied by change in plasma atrial natriuretic polypeptide concentrations. Conversely, the rise in circulating atrial natriuretic polypeptide during combined acute hypoxemia and hypercapnic acidosis was not associated with an increase in urinary sodium excretion. These observations do not exclude a role for atrial natriuretic polypeptide in altering sodium excretion during acute blood gas derangements, since the effects of this autacoid on renal sodium excretion may have been offset by other counterregulatory mechanisms of sodium excretion activated during the acute blood gas derangement.


Studies of acquired sustained hypernatraemia occurring in a diabetic patient. We describe studies undertaken in a diabetic patient with acquired sustained severe hypernatraemia. Arginine vasopressin levels and thirst scores were grossly subnormal in the presence of marked hypernatraemia but arginine vasopressin increased normally under the influence of negative pressure-induced hypovolaemia. Despite very low levels of arginine vasopressin, polyuria was not a feature suggesting acquired renal hyper-responsiveness. This patient is an additional case of acquired osmoregulatory dysfunction, whose features do not fall neatly into previously described categories.


Bartter's syndrome: evidence suggesting a distal tubular defect in a hypocalciuric variant of the syndrome. Renal tubular function was examined in 5 adult patients aged 18-30 years with Bartter's syndrome associated with renal magnesium wasting and hypocalciuria. In the 3 patients studied during hypotonic saline diuresis, distal tubular fractional chloride reabsorption was lower than that reported in normal subjects. In response to a single intravenous dose of furosemide (40 mg), the increment in the excretion of sodium, chloride, and magnesium was equal to or greater than in normal subjects, while in 2 patients, in response to intravenous chlorothiazide (500 mg), the increment in sodium excretion was less than in normal subjects. Magnesium chloride infusion was undertaken in 2 patients in order to compare magnesium and calcium excretions at similar plasma magnesium levels in patients and in normal subjects. The patients exhibited magnesium wasting only at normal or low plasma magnesium levels, while calcium excretion was reduced in the patients at normal and elevated plasma magnesium levels. We conclude that in these patients the enhancement of renal magnesium reabsorption by hypomagnesemia is defective, and the hypomagnesemia is not the cause of the hypocalciuria. The tubule defect responsible for these abnormalities of magnesium and calcium excretion may be located beyond the side of action of furosemide, in the thiazide-sensitive segment of the distal convoluted tubule.


Inappropriate hypercalcitriolemia in ileum-resected patients with Crohn's disease. Twelve patients who had undergone ileal resection because of Crohn's disease were studied for measurements of serum 25-hydroxyvitamin D3 (25-OHD3), 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], intact parathyroid hormone (PTH), ionized calcium and phosphate in median 6 years after the intestinal resection. 24 normal subjects matched for age, sex and season served as controls. Despite a reduced level of 25-OHD3 (p less than 0.05) and normal levels of ionized calcium, PTH, phosphate and renal function the median level of 1,25(OH)2D3 was significantly raised (p less than 0.001). Further analysis showed that the inappropriately increased level of 1,25(OH)2D3 was significantly positive related to the concentrations of its substrate (25-OHD3) and PTH. The cause for inappropriate hypercalcitriolemia is uncertain. Contribution from extrarenal 1-hydroxylation of 25-OHD3 as in sarcoidosis is suggested.


Roles of hormones in plasma potassium alteration in acute respiratory acidosis in dogs. The present study was conducted to examine the roles of hormonal factors in plasma potassium alterations in acute respiratory acidosis. Respiratory acidosis (pH, 7.07-7.10) induced by the inhalation of 10% CO2, 20% O2 and 70% N2 mixed gas caused an increase in the plasma potassium concentration beyond that of the control of 3.44 +/- 0.12 (mean +/- SE) to 4.36 +/- 0.07 mEq/l (p less than 0.01) within 180 min. The plasma norepinephrine concentration was also noted to significantly increase at the same time. Phentolamine (40 micrograms/kg/min i.v.) did not affect the degree of acidosis or acidosis-induced hyperkalemia. No significant changes in the plasma levels of epinephrine, insulin, glucagon, cortisol or aldosterone could be detected. Hormonal factors would thus appear not to be essential to potassium movement from intracellular to extracellular compartments in acute respiratory acidosis.


Platelet-activating factor attenuates the arginine vasopressin-induced fall of transepithelial resistance across inner medullary collecting duct monolayers. Platelet-activating factor (PAF) is a vasoactive substance produced in the medulla which may alter Na excretion by the kidney. To examine a possible site and mechanism of action of PAF on the kidney, we evaluated the effects of PAF on transepithelial resistance and intracellular calcium concentration ([Ca2+]i) in cultured rat inner medullary collecting duct cells. Exposure of inner medullary collecting duct (IMCD) cell monolayers to PAF had no significant effect on basal transepithelial resistance. By contrast, incubation of IMCD cells with PAF reversibly blocked the fall in transepithelial resistance induced by arginine vasopressin (AVP): -11.1 +/- 1.4 omega.cm2 with AVP versus -0.02 +/- 1.6 omega.cm2 with PAF and AVP. Exposure of IMCD cells to PAF in Ca-replete medium caused a rise in intracellular calcium from 155 +/- 25 to 491 +/- 68 nM. By contrast, exposure of IMCD cells to PAF in Ca-free medium produced no change in [Ca2+]i. Because the rise in [Ca2+]i induced by PAF was absent in Ca-free medium, transepithelial resistance across IMCD monolayers was examined in calcium-free medium. The effect of PAF to block the fall in transepithelial resistance induced by AVP was maintained in Ca-free medium. These data suggest that PAF modulates the effect of AVP on conductive channels by a mechanism distinct from changes in intracellular calcium.


[Ewing's sarcoma of the bone. Anatomoclinical study of 424 cases]. The clinic-epidemiologic and prognostic features of 424 cases of Ewing sarcoma observed at "Rizzoli" Institute between 1972-1990 are reported. The incidence of the tumor was higher in the second decade of life with slight predominance in the male sex. The primary lesion was especially localized in the extremity and the ratio lower/upper extremity was 5/1. We did not find, in contrast with other Authors, differences in height or in incidence of congenital malformations when compared to controls. The pain was the first common symptom at debut (90%) followed by swelling (50%) and fever (40%). Diagnosis was made 5.5 months after the first symptom and the delay was due to wrong diagnosis at debut in 3/4 of the patients. Laboratory tests showed anemia in about half of the patients and increased value of ESR (60%) and LDH (40%). Seventy-one of the patients were metastatic at presentation, none of these patients were still living after three years. At a median follow-up of 9 years 43% of the patients with localized disease, treated with adjuvant and neo-adjuvant chemotherapy remained continuously disease free, 53% developed metastatic disease and/or local recurrences and 2% had a second malignancy. In 24% of the patients metastases and/or local recurrences appeared three years after the beginning of treatment. Better prognosis was observed in female patients, without fever at diagnosis, with tumor localized at extremities and with normal value of hemoglobin, ERS and LDH. Regarding the type of treatment, better results were obtained by surgery of the primary tumor and by chemotherapy with four drugs (vincristine, cyclophosphamide, adriamycin dactinomycin) in comparison to radiotherapy of the primary tumor and chemotherapy with three drugs (vincristine, cyclophosphamide, adriamycin).


[A case of growth retardation of rare occurrence]. The Authors describe an uncommon case of growth retardation; the clinical and radiological elements that the Authors to a diagnosis of spondyloepiphyseal dysplasia (SED) are noted; they compare this to other diagnosis of different types of growth retardation, they underline the necessity of taking these rare types into consideration before undergoing diagnostic procedures that would be costly both to the patient and society.


American Indian health. Providers, communities surmount profound problems. Minnesota's urban and rural Indian communities today face a similar set of complex and daunting health problems. No one overriding issue exists, nor does an overall solution. While staff shortages, a dire lack of Indian health professionals, and inadequate financial resources play a role, poverty, racism, lifestyle, alcoholism, and cultural change and conflict all further complicate health problems for Indian people.


Exertional compartment syndrome in covert mild hemophilia. A case report. A 37-year-old white male experienced unexpected postoperative bleeding after fasciotomy and decompression for left pronator and compartment syndromes of the forearm. He was subsequently diagnosed with a mild form of hemophilia A. One year later, surgery was required for right pronator and compartment syndromes. Pre- and postoperative cryoprecipitate infusions controlled bleeding following the second operation until the patient discontinued his infusions, resulting in a wound hematoma. Covert mild hemophilia is implicated in the pathogenesis of his compartment syndromes.


Physician liability for failure to remove breast implants. In cases where the failure to remove breast implants later results in injury, physicians may be exposed to liability if it can be shown that the woman would have removed the implants had she received more adequate or complete advice regarding the risks of keeping the implants in place. It is possible that courts may impose liability on physicians for failing to take affirmative steps to remove the implants under limited circumstances. In cases where adequate warnings are given, however, liability will rest only where causation can be shown. Proving causation is always fact-specific and will vary from case to case. In general, it must be established that the physician did not give complete advice and that if better advice had been given, the patient would have had the implants removed, preventing later injury. Physicians have at least three potential defenses to negligence actions regarding the failure to remove breast implants. First, the physician may maintain that he or she warned the patient and that the patient chose to ignore the advice. Second, the physician may rely upon available FDA and manufacturer recommendations that support the physician's advice regarding removal. Finally, the statute of limitations may bar a claim if more than two years have elapsed since the date of treatment.


Private pensions. A less taxing alternative. The results of the Joneses' coordinated retirement income and estate planning strategies are as follows: 1. The Joneses maximized their estate assets by converting an inefficient estate asset (the qualified retirement plan) into an efficient estate asset (the income-tax-free death benefit) without jeopardizing their current or future standard of living or the value passed on to their heirs. This allows them to satisfy their conflicting objectives. 2. They added flexibility to their future family gifting plans by providing themselves a secure income for the rest of their lives. 3. They fulfilled their desire to protect their family against government confiscation of retirement plan assets in the event they both die before using all their qualified retirement assets. This private pension plan strategy is obviously not available to everyone, nor is it appropriate for everyone. This solution worked well for this client, but everyone's situation is unique. Before creating such a plan, it is important to review all the factors in an individual's financial picture, including financial and retirement objectives and investment risk tolerance. Although this is an innovative idea that may solve a pension dilemma, it should not be used in place of qualified retirement plans but, rather, used in conjunction with such a plan. The private pension plan does not work with all insurance products or all insurance companies. Choosing the right company and product for each client requires care and expertise.


[Fragoso-Cantù syndrome. Description of a neonatal case]. We report on a newborn with psychomotor retardation, muscle hypotonia, typical facies, little subcutaneous fat, arachnodactyloid hands and feet, diffuse cortical and subcortical cerebral atrophy. A comparison is made with the Marfan syndrome and it is concluded that the morphoneurological anomalies are compatible with the diagnosis of Fragoso-Cantù syndrome.


[Celiac disease in Piedmont. An epidemiological-clinical study]. The incidence of coeliac disease (CD) was calculated on 304 patients under eighteen who were born in the city of Turin and its province in the years 1975-1989; the prevalence on 494 patients who live in the Piedmont Region. The mean crude yearly incidence was 0.511/1000 (1:1957 live birth). It varied from year to year, reaching minimum values in the years 1984-1987. In a contemporary epidemiological study, the mean crude incidence of CD in Italy was 1.2/1000 (1:833 live birth) twice the rate observed in Turin. The prevalence of paediatric CD in Piedmont was 113 per million inhabitants. Since CD has a normal life expectancy, its prevalence may be expected to increase. In the provinces of Novara, Alessandria and Asti CD prevalence was lower than in the others. Mean age at onset was 6 mos in 1975 and increased to 34 mos in 1989. Mean age at diagnosis was 15 mos in 1981, and 7 yrs in 1989. Symptoms were more numerous and severe in patients under 12 mos of age, and became fewer and often atypical in older children. We can therefore speculate that the trend towards a decreasing incidence of CD in recent years my be due to delayed diagnosis.


The Minnesota Fatal Accident Circumstances and Epidemiology Study. Surveillance of occupational fatalities. This report describes the Minnesota Fatal Accident Circumstances and Epidemiology Study (MN FACE), a new federally funded initiative to study fatal injuries in the workplace. Its primary objective is to reduce occupational fatalities. Fatalities due to falls, electrocutions, and asphyxiation caused by entry into confined spaces are currently investigated in Minnesota. MN FACE determines risk factors associated with fatalities then develops interventions for their mitigation or elimination. A comprehensive, statewide surveillance system, including state agencies, associations, organized labor, and industry, has been established to reduce the amount of bias in reporting.


The Patient Self-Determination Act. Advance directives available to Minnesota patients. The Patient Self-Determination Act requires most health care institutions to inform patients of their right to refuse medical care and their right to provide advance direction regarding their wishes should they become incompetent. Although the PSDA does not apply to physicians, it will probably increase the demand for communication with patients on such matters. Patients will undoubtedly ask how to formulate advance directives. While physicians should make it clear that they are not providing legal advice to patients on such issues, they may wish to indicate that a guardianship and a living will are options available under Minnesota law. Additionally, as indicated above, a number of arguments exist that durable powers of attorney for health care are valid in Minnesota, as well. Physicians should familiarize themselves with living will forms and may wish to make them available to patients upon request. (Living will forms can be obtained by contacting the Minnesota Medical Association at 612/378-1875.) Patients with questions regarding durable powers of attorney should be advised to seek legal counsel.


Health care reform in Minnesota. Implications for the rural physician. Minnesota's health care reform plan (by any name) is a cost-containment bill with provisions to provide health insurance for some uninsured people, to examine quality of care, to increase support for rural provider education and migration to rural practice, and to develop state and regional health planning procedures. It is an ambitious bill with very tight time frames, vague language, and heavy reliance on regional commissions and volunteer groups that are just now being established. Will it have an impact on rural health care? Undoubtedly, it will. But somewhere between what the bill says and the desired outcome is a void that physicians can help fill with constructive work and criticism. If physicians do not take the lead, someone else will fill that void--nonphysician providers, legislators, bureaucrats, or consumers. Or the structure could implode, taking all of us with it.


Twin cities health care mergers, acquisitions, and affiliations. Implications for independent physician practices. "The health care system in Minnesota, especially in the Twin Cities area, is currently undergoing change that can best be characterized as a consolidation of providers into larger and larger groups (multispecialty clinics, hospital/physician mergers, and expanded HMOs and PPOs). These changes are intended to produce economies of scale, less duplication of services, and better control of costs and quality of health care. Where does this leave the more traditional, smaller multispecialty or single-specialty practices often referred to as 'independents'?... How can independent groups respond to these trends in order to survive in the new health care marketplace?"


Valuing the primary care patient base.

Valuing the primary care patient base. This analysis, albeit limited, can help clinics and integrated health systems with their medical staff planning, and it demonstrates the importance of the primary care patient base as a foundation for health services planning and economic and market strategies. It is important to note, however, that when primary, specialty, subspecialty, surgical, and hospital care are well planned and marketed, it is virtually impossible to identify the relative contribution of each to the overall success of the system. Consequently, primary care physicians should not attribute the value discussed here solely to their efforts. Hospital executives should be mindful of two related issues: First, some administrators remain focused on inpatient services when outpatient services may offer greater economic potential over time. Ambulatory interventional diagnostics and therapeutic procedures (e.g., outpatient surgery) are often undervalued or overlooked in medical staff development plans. The net profits available from additional ambulatory surgical cases can be significant. Second, success in developing a medical staff plan requires more than calculating physician supply and demand ratios. A balance must be struck between meeting the hospital's needs for additional physicians and meeting the needs of the existing medical staff. A number of hospital executives have found that devoting all physician-related resources to recruiting new staff can create resentment among physicians who have remained loyal to their hospitals without financial and other practice incentives and inducements. We encourage multispecialty group practices to become students of primary care development as well and urge them to guard against focusing on the high overhead costs of primary care without recognizing the value of an organized primary care strategy.(ABSTRACT TRUNCATED AT 250 WORDS)


[Importance of evoked potentials in the evolutive prognosis of coma during cerebral anoxia in adults]. Ten cases of postanoxic coma have been studied. A clinical neurological examination with study of brainstem reflexes and the EEG recording were made on the first day (J1), the third day (J3) and the tenth day (J10) after the start of the coma. A recording of the visual evoked potentials, the brainstem evoked potentials and the somatosensory potentials combined was made at the same time. A clinical examination is carried out one month after the coma when the patient survives. According to the initial clinical examination, we distinguished 3 groups of subjects. The results show that in group III the visual evoked potentials such as EEG have a slightly significant prognostic value; frequently the near outcome lead to death whereas EEG activity persists and the visual evoked potentials disappear later. On the other hand, the association of brainstem evoked potentials and somatosensory potentials clearly has a higher prognostic value in this group. The disappearance of the shortest brainstem responses and the cortical somatosensory responses is clearly an unfavourable prognosis. This disappearance associated with the end EEG activity is the absolute proof of brain death. On the other hand, the persistence of these responses is of a better prognosis at least on the survival level, but their degradation during evolution is unfavourable.


Electrical status epilepticus on eye closure: a case report. The authors present the clinical case of a boy manifesting eyelid myoclonias on eye closure. The corresponding electroencephalographic recording was characterized by unceasing spike activity, constituting a sort of electrical status epilepticus. There was no loss of consciousness or differences between results of neuropsychological tests with eyes open and closed.


Partial childhood epilepsy and reaction time: the effect of interictal EEG discharges. A study was conducted on seven children (five females and two males, aged 5.7-13.1 years) affected with partial epilepsy which was well controlled by therapy. A computer was connected on-line to a polygraph and during two EEG recordings, the subject had to react to the appearance of a colored rectangle on the display screen by pushing a key on the keyboard: these events were automatically marked on the trace of a polygraphic channel. By means of Anova analysis it was demonstrated that during the same recording, reactions simultaneous to paroxysmal discharges were not significantly slower than those measured during free intervals. However, in the same patient, reaction times were significantly prolonged during recordings characterized by a higher rate of EEG paroxysmal activity.


[Comparative study by computerized EEG of dementia of the ALzheimer type and Parkinson's disease with dementia]. A computerized EEG (cEEG) study was performed in two groups of patients with dementia of the Alzheimer type (DAT) and with Parkinson's disease with dementia (PDD). Compared to control subjects suffering from Parkinson's disease without dementia, both groups demonstrated similar slowing down of background activity. However, there were more low frequency components, defined as between 2.5-7 Hz, and less topographical differentiation in PDD than in DAT. Furthermore, more severe impairment of cognitive functions was observed in DAT, but their psychometric score correlated with slowing down of EEG only in DMP. These observations emphasize the influence of the subcortical/cortical axis both in dementia of Parkinson's disease and in the neurophysiology of the EEG.


[Investigation via electroencephalogram with sphenoidal electrodes of a case of reading epilepsy: role of the temporal lobe in the emotional evocation of seizures]. Reading epilepsy in a 20-year-old male. Electroencephalographic study with sphenoidal electrodes localized the onset of critical spikes in the temporal areas (especially the left). The frequency and diffusion of critical spikes were increased when material read had an emotional content. This case report supports the "communication" hypothesis as opposed to hypotheses that emphasize proprioceptive and other "lower order" stimuli in evoking seizures while reading. The authors discuss the role of the temporal lobe in reading: lexical function, treatment of visual information and emotional integration of stimuli.


Perineal motor potentials to magnetic stimulation, pudendal evoked potentials and perineal reflex in women. Motor potentials to transcranial and lumbar magnetic stimulation were recorded from the perineum in 14 healthy women. The response to transcranial stimulation presented an onset at 20.2 +/- 1.3 ms and a negative peak at 25.1 +/- 1.9 ms. Lumbar responses presented an onset at 5.1 +/- 0.8 ms, and the motor central conduction time measured 14.4 +/- 1.5 ms. Perineal reflex, cortical and lumbar pudendal evoked potentials were recorded after electrical stimulation of the labia minora. These tests are of possible clinical use in the evaluation of sphincter disturbances as they investigate the afferent and efferent pathways concerning pudendal nerve function.


A prospective study of the transition to phacoemulsification and small incision cataract surgery. Phacoemulsification is an increasingly popular method of performing cataract surgery. The procedure remains controversial. Opponents of phacoemulsification maintain the procedure has an unacceptably high complication rate during transition to the technique. This prospective study found that the many advantages of phacoemulsification were safely introduced into a moderate sized community practice. The surgical complication rate was very low and visual acuity statistics excellent.


Esophageal stricture: results of dilation of 300 patients. Three hundred patients underwent 1,177 esophageal dilations over a nine-year period. There were 164 men and 136 women. Mean age was 63 years. Etiology of stricture was peptic (160), Schatzki's ring (124), cancer (8), post-surgical (3), post-radiation (2), caustic ingestion (1), and esophageal web (2). Dilators used were Maloney red-rubber mercury weighted (78.1%), Savary wire-guided (15.2%), Eder-Puestow (6.3%) and Balloon (0.4%). Fluoroscopy was used in 98% of cases. One hundred and two of the 111 patients with peptic strictures observed for longer than six months had successful dilation. Forty-five of these patients (40.5%) required 54 redilations to maintain relief of dysphagia. Nine patients were refractory to dilation, two needing serial dilation and seven surgery. All Schatzki's rings were treated successfully. Ten of 82 patients followed for greater than six months needed redilation (12%). Morbidity was 0.2% with two complications occurring, an esophageal perforation and one case of hematemesis. There was no mortality.


Skin expansion as preparation for an opening wedge osteotomy of the mid-foot in arthrogryposis. A case report is presented in which tissue expansion is used to provide the additional skin needed during an opening wedge mid-foot osteotomy to correct a varus foot deformity in a patient with arthrogryposis multiplex congenita. Tissue expansion is a relatively new method of acquiring coverage for wounds which may have advantages over previous techniques. The risks and drawbacks of this technique will be described in detail.


Pertussis vaccination: acellular pertussis vaccine for the fourth and fifth doses of the DTP series update to supplementary ACIP statement. Recommendations of the Advisory Committee on Immunization Practices (ACIP). General recommendations on pertussis prevention were issued August 8, 1991, in the ACIP statement on diphtheria, tetanus, and pertussis (1). A supplementary statement on the use of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) was issued February 7, 1992 (2) after the licensure of ACEL-IMUNE, prepared by Lederle Laboratories. With the recent licensure of a second DTaP product, Tripedia, this statement updates the supplement. Tripedia has a formulation that differs from that of ACEL-IMUNE. Both DTaP vaccines are licensed for use only as the fourth and/or fifth doses of diphtheria, tetanus, and pertussis vaccination; they are not licensed for the initial three-dose series for infants and children, regardless of age. Whole-cell DTP should continue to be used for the initial three-dose series and remains an acceptable alternative for the fourth and fifth doses. For details on the background, indications, use, and precautions and contraindications of DTaP, refer to the earlier supplementary statement (2).


Pneumonic plague--Arizona, 1992.

Pneumonic plague--Arizona, 1992. On August 26, 1992, a 31-year-old male resident of Tucson, Arizona, died of an illness subsequently diagnosed as primary pneumonic plague. This is the 10th case of plague reported in the United States in 1992, the first pneumonic plague case this year, and the first plague fatality reported since 1987 (CDC, unpublished data). This report summarizes the investigation of this case by county, state, and federal public health officials in Arizona and Colorado.


HIV counseling and testing services from public and private providers--United States, 1990. Human immunodeficiency virus (HIV) counseling and testing (CT) services are key elements of the national HIV-prevention strategy (1,2). Although the number and characteristics of persons receiving CT through publicly funded programs are monitored by CDC's CT data system (3), this system does not provide information about persons tested for HIV antibody by physicians in the private sector, hospitals, and other nonpublicly funded sources. This report summarizes data from CDC's 1990 National Health Interview Survey (NHIS) AIDS Supplement (4) regarding CT received from public and private providers.


Alcohol-related hospitalizations--Indian Health Service and tribal hospitals, United States, May 1992. Alcohol use is directly responsible for hospitalizations resulting from chronic conditions, such as alcoholic liver disease and alcoholic psychoses; in addition, alcohol use can be a contributing factor in other conditions, such as infectious diseases and injuries, that require hospital admission. Based on discharge data from Indian Health Service (IHS) facilities and CDC's National Hospital Discharge Survey (1), the proportion of alcohol-related hospitalizations (ARHs) among American Indians/Alaskan Natives has been reported as 2.5 times that for the total U.S. population. However, these estimates rely on a limited set of alcohol-defined diagnoses that are primarily associated with chronic alcoholism. To characterize more accurately the relation of alcohol use to inpatient admissions to IHS and tribally operated hospitals in the United States, IHS conducted a 1-day survey of ARHs in these facilities on Monday, May 18, 1992. This report summarizes preliminary results from the survey.


Behaviors related to unintentional and intentional injuries among high school students--United States, 1991. During 1988, injuries were the leading cause of death among persons aged 15-19 years in the United States (CDC, unpublished data, 1988). Of all deaths in this age group, 42% were motor-vehicle related, 13% were due to homicide, 13% to suicide, and 11% to other types of injuries and adverse effects. This report presents 1991 self-reported data on the prevalence of selected behaviors (i.e., attempted suicide, physical fighting, weapon-carrying, safety-belt use, motorcycle-helmet use, and bicycle-helmet use) associated with these causes of death among 9th-12th-grade students in the United States.


National Coalition for Adult Immunization: activities to increase influenza vaccination levels, 1989-1991. Older persons and persons with underlying health problems are at increased risk for complications of influenza infection; however, only 30% of persons aged > or = 65 years are vaccinated against influenza each year (1). This report describes initial efforts by the National Coalition for Adult Immunization's (NCAI) Influenza and Pneumonia Action Group (IPAG) to increase influenza vaccination of adults in the United States during 1990-1993, and highlights National Adult Immunization Week, October 25-31, 1992.


Poliomyelitis--Netherlands, 1992.

Poliomyelitis--Netherlands, 1992. From September 17 through October 9, 1992, five cases of poliomyelitis were reported in the Netherlands among members of religious groups that generally do not accept vaccination. This report summarizes investigations of these five cases by the Netherlands' Office of the Chief Medical Officer of Health, the Laboratory of Virology, National Institute for Public Health and Environmental Protection, and the Municipal Health Services in Rotterdam. The investigation indicated that none of the cases were epidemiologically linked; two of the cases (cases 1 and 2) had some history of receipt of polio vaccine, while three (cases 3-5) had no history of polio vaccination. This report summarizes the investigation of these cases.


Lead ingestion associated with ceramic glaze--Alaska, 1992. In August 1992, a physician notified the Alaska Division of Public Health (ADPH) that three patients at a psychiatric hospital had consumed ceramic glaze during ceramic therapy (i.e., recreation therapy involving the production of ceramic ware), and two of these patients had elevated blood lead levels (BLLs). This report summarizes the ADPH's investigation of these ingestions.


Public health focus: surveillance, prevention, and control of nosocomial infections. Nosocomial infections are estimated to involve more than 2 million patients annually (1, 2) and in 1992 cost more than $4.5 billion (3). Adverse consequences of nosocomial infections and their associated costs vary by type of infection (Table 1) (3). Hospital-based programs of surveillance, prevention, and control of nosocomial infections were developed during the 1950s and refined in the United States during the 1960s and 1970s. However, questions regarding the efficacy and cost-effectiveness of these programs have persisted. This report examines knowledge about the effectiveness of nosocomial infection surveillance, prevention, and control and their cost-benefits.


Plague--United States, 1992.

Plague--United States, 1992. From January 1 through October 15, 1992, 11 human plague cases, including one described recently (1), have been reported in the United States. This report summarizes the epidemiologic information on these cases and provides recommendations for control of plague.


Epidemic early syphilis--Montgomery County, Alabama, 1990-1991. In Montgomery County (1990 population: 209,085), Alabama, an epidemic of early syphilis (ES) (i.e., primary, secondary, and early latent) involving 1010 cases occurred from August 1990 through November 1991 (Figure 1). From June 17 through November 7, 1991, the Alabama Department of Public Health (ADPH) and CDC initiated an intervention campaign to reduce the incidence of ES; the intervention increased case-finding primarily through partner notification (PN) and cluster investigations.* This report assesses the intervention campaign by describing 1) the results of PN/cluster investigation interviews during the intervention, 2) the relation between reported crack cocaine use and PN/cluster investigation results, 3) a comparison of interview results for the first 6 weeks of the campaign (i.e., early campaign period) with the 6-week period immediately before the campaign (i.e., precampaign period), and 4) the syphilis morbidity trends for 1990 and 1991.


Human psittacosis linked to a bird distributor in Mississippi--Massachusetts and Tennessee, 1992. During April-May 1992, CDC was notified of a possible outbreak of psittacosis involving members of two families in Massachusetts and Tennessee who had recently purchased birds as pets. In the subsequent investigation of this problem, human psittacosis was defined as a fourfold rise in complement-fixing antibody titer to > or = 32 or a single titer of > or = 32 in a patient with fever and/or respiratory symptoms. This report summarizes the investigation of this problem.


Nutritional needs surveys among the elderly--Russia and Armenia, 1992. The ongoing social, political, and economic changes in the 15 republics of the former Soviet Union have resulted in hyperinflation of the Soviet Union ruble (SUR), regional conflicts, and other hardships for the populations of these republics (1). In January 1992, a public health assessment in Russia indicated that the elderly--most of whom subsist on fixed incomes and among whom the prevalences of decreased mobility or chronic illnesses may be substantial--are at greatest risk because of declining social support. During March-May 1992, CARE, in collaboration with CDC, conducted three surveys in Russia and Armenia to assist in targeting the delivery of food and medical humanitarian aid to the most needy among the elderly. This report summarizes findings from these surveys.


Chaparral-induced toxic hepatitis--California and Texas, 1992. Cases of acute toxic hepatitis in two patients--one in California and one in Texas--have been attributed to ingestion of an herbal nutritional supplement product derived from the leaves of the creosote bush known commonly as chaparral. This report summarizes the investigations of these cases.


Anonymous survey for simian immunodeficiency virus (SIV) seropositivity in SIV-laboratory researchers--United States, 1992. CDC recently reported on two laboratory workers who had seroconverted against simian immunodeficiency virus (SIV) following work-related exposure to the virus. In follow-up, the National Institutes of Health (NIH) and CDC have collaborated on an anonymous SIV seroprevalence study using stored serum samples from some laboratory workers and animal caretakers involved in SIV research at some of the NIH-sponsored facilities in the United States. This report summarizes the study.


Surveillance for occupationally acquired HIV infection--United States, 1981-1992. Public health surveillance for and risk-assessment studies of human immunodeficiency virus (HIV) infection provide a basis for formulating measures to minimize the risk for occupational transmission of HIV to health-care workers (1-6). Data on occupational transmission of HIV have been provided by two CDC-supported national surveillance systems: one initiated in 1981 for acquired immunodeficiency syndrome (AIDS) cases and one initiated in 1991 for HIV infections acquired through occupational exposures (Table 1). This report summarizes data on occupationally acquired HIV infection from these surveillance systems through September 1992.


Community awareness and use of HIV/AIDS-prevention services among minority populations--Connecticut, 1991. Human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS)-prevention efforts supported by the federal government include programs offered through community-based organizations (CBOs) and state and local health departments (1). To assess the extent of community awareness and use of these HIV/AIDS-prevention services among Hispanics and non-Hispanic blacks in three cities in Connecticut, the Connecticut State Department of Health Services (CSDHS) included questions on HIV/AIDS-prevention programs in its population-based chronic disease and health risk survey. This report summarizes survey results regarding awareness and use of these community-based programs during 1991.


ATPase activity of SopA, a protein essential for active partitioning of F plasmid. The sopA, B, C genes of the F plasmid play an essential role in plasmid partitioning during cell division in Escherichia coli. In this paper, the products of the sopA and sopB genes were isolated and their biochemical activities studied. [alpha-32P]ATP was cross-linked to the SopA protein by UV irradiation; this cross-linking was observed only in the presence of magnesium ion, and was competitively inhibited in the presence of non-radioactive ATP, ADP and dATP, but not other NTPs or dNTPs. In contrast, no ATP binding activity was detected for the SopB protein. The SopA protein showed a modest magnesium ion-dependent ATPase activity and this activity was stimulated in the presence of DNA. The ATPase activity in the presence of DNA was further stimulated by addition of the SopB protein. However, the SopB protein alone failed to stimulate the ATPase activity.


A deletion derivative of the kalilo senescence plasmid forms hairpin and duplex DNA structures in the mitochondria of Neurospora. A novel deletion derivative, delta kal, of the kalilo senescence plasmid from Neurospora intermedia, was recovered from a culture treated with chloramphenicol. The deletion derivative exists in mitochondria as two different, equally abundant forms: a 2.8 kb duplex DNA molecule (delta kal-2.8) and a 1.4 kb hairpin form (delta kal-1.4). The delta kal-2.8 plasmid contains the 1366 bp terminal inverted repeats and a partially duplicated 102 bp segment of the unique sequence of the 8.6 kb kalilo plasmid. In contrast, the delta kal-1.4 hairpin plasmid appears to result from the folding of single strands that are generated during the replication of delta kal-2.8. Both forms of delta kal have covalently linked terminal proteins. Sequence analysis suggests that delta kal was generated either by slippage of the tip of a growing strand during the replication of kalilo, or by illegitimate recombination between two copies of the plasmid at non-homologous palindromic sequences that might form cruciform structures. In either case, the deletion process was mediated at least in part by an inverted repeat of 5 bp in the unique region of kalilo. Since the terminal segments of kalilo DNA that are implicated in plasmid integration might also form cruciform structures, it is possible, but improbable, that the process that generated the first delta kal molecule is related to that which mediates integration of the plasmid into mitochondrial DNA.


Translational readthrough at nonsense mutations in the HSF1 gene of Saccharomyces cerevisiae. The HSF1 gene of Saccharomyces cerevisiae directs the synthesis of the heat shock transcription factor, HSF. The gene is essential; disruption mutations are lethal. Using a plasmid shuffle screen, we isolated mutations in the HSF1 gene after in vitro mutagenesis of plasmid DNA with hydroxylamine. From a collection of both conditional (temperature-sensitive) and unconditional lethal mutations, we recovered mutations that map exclusively to the 5' half of the gene. All are nonsense mutations, including conditional mutations that map 5' to the portion of the HSF1 gene that encodes the DNA-binding domain of the transcription factor. For one such mutation, we demonstrated that the nonsense mutation is subject to translational readthrough, even though there are no known nonsense suppressors in the genetic background of our strain. Our results suggest that the HSF protein is highly tolerant of amino acid changes, a conclusion that is consistent with the very low degree of evolutionary conservation among HSF proteins. Our results also suggest that translational readthrough occurs with moderate efficiency in yeast, particularly when the terminator codon is followed immediately by an A or C residue. This result illustrates that the inference of gene function from mutant phenotype depends critically upon the analysis of a true null allele, and not merely an amber or ochre allele.


Brassica anther-specific genes: characterization and in situ localization of expression. A cDNA library of Brassica napus (cv. Westar) was constructed using poly(A)+ RNA isolated from developing anthers of flower buds 2-3 mm in length. Differential hybridization, using cDNA probes complementary to poly(A)+ RNA from developing anthers or seedlings, was used for initial screening. In addition to Southern and Northern blot analyses of selected clones, RNA-PCR assays and in situ hybridization were used to study the temporal and spatial gene regulation in anthers at the transcriptional level. Five independent cDNA clones, showing no cross-hybridization to one another, were characterized, and their expression patterns could be grouped into three distinct categories. Two cDNA clones, BA112 and BA158, are tapetum-specific: the corresponding mRNAs accumulate in young anthers and decline as the tapetum cells degenerate later in anther development. The transcripts represented by BA54 and BA73 accumulate late in anther development and reach a maximum level in mature anthers prior to anthesis; BA54 has been confirmed to be pollen-specific. The third category, represented by BA42, is found to encode a protein sharing 64-67% amino acid similarity with chalcone synthase (CHS) from various plant species; the transcript is localized in the peripheral cells of the vascular bundle, tapetum, and developing microspores.


Multiple plant RNA binding proteins identified by PCR: expression of cDNAs encoding RNA binding proteins targeted to chloroplasts in Nicotiana plumbaginifolia. Pre-mRNA processing in eukaryotic cells requires the participation of multiple protein factors and ribonucleoprotein particles. One class of proteins involved in this process are RNA-binding proteins, which contain a domain of ca. 90 amino acids with a characteristic ribonucleoprotein consensus sequence (RNP-CS). A PCR approach that is suitable for the characterization of RNP-CS-type proteins is described. Fifteen different RNA-binding domains were amplified from Nicotiana tabacum (tobacco) using oligonucleotide primers specific for the sequences (K/R)G(F/Y)(G/A)FVX(F/Y) and (L/I/V)(F/Y)(V/I)(G/K)(N/G)L, which are conserved in known RNP-CS proteins. Using the tobacco domains as probes, cDNAs encoding two RNA-binding proteins, each containing two RNP-CS-type domains, were characterized in N. plumbaginifolia. The proteins, designated CP-RBP30 and CP-RBP31, are targeted to chloroplasts as demonstrated by expression of epitope-tagged cDNAs in transfected protoplasts, followed by indirect immunofluorescence. High levels of mRNA for each protein were found in leaves but not in roots, and expression of the CP-RBP31 mRNA was strongly regulated by light. The N. plumbaginifolia proteins described in this work are distinct from chloroplast RNA-binding proteins characterized recently in tobacco and spinach.


Protein export elements from Lactococcus lactis. Broad-host-range plasmids carrying alpha-amylase or beta-lactamase reporter genes lacking a signal sequence were used to select export elements from Lactococcus lactis chromosomal DNA that could function as signal sequences. Fragments containing such elements were identified by their ability to direct the export of the reporter proteins in Escherichia coli. Several of the selected export elements were also active in Bacillus subtilis and L. lactis, although the efficiencies depended strongly on the host organism and reporter gene used. The export elements AL9 and BL1 were highly efficient in L. lactis in the expression and secretion of at least two heterologous proteins (Bacillus licheniformis alpha-amylase and E. coli TEM-beta-lactamase). AL9 even permitted growth of this organism on starch as the sole carbon source. Nucleotide sequence analysis of five selected fragments indicated that these encode oligopeptides with the major characteristics of typical signal peptides. The putative expression signals had a limited similarity to previously described expression signals for E. coli, B. subtilis and L. lactis. Differences in both expression and export efficiency are likely to underlie the host-specific effects.


Ammonia regulation of the Rhizobium meliloti nitrogenase structural and regulatory genes under free-living conditions: involvement of the fixL gene product? The expression under microaerobic conditions of the Rhizobium meliloti nifA and consequently the nifHDK genes was found to be negatively regulated by ammonia and nitrate. Assimilation of the ammonia to glutamate and glutamine is not required for this regulation to occur. This indicates that ammonia itself, and not a product of its metabolism, may be regulating nif expression. Unlike the situation in Klebsiella pneumoniae, NtrC is apparently not involved in mediating the ammonia effect on nifA expression in R. meliloti. Neither does the fixK gene product, which is known to regulate nifA in R. meliloti, appear to be involved in mediating the ammonia effect. The regulation of nifA by ammonia is shown to be mediated through the FixL protein. A truncated fixJ gene, the product of which has been shown to induce nifA expression irrespective of the oxygen status of the cell, also circumvented the repressive effect of ammonia on nifA expression. This suggests that the ammonia effect is mediated through the FixLJ regulatory cascade. Interestingly no effect of ammonia on fixK expression was observed.


Insertional disruption of the nusB (ssyB) gene leads to cold-sensitive growth of Escherichia coli and suppression of the secY24 mutation. The Escherichia coli gene ssyB was cloned and sequenced. The ssyB63 (Cs) mutation is an insertion mutation in nusB, while the nusB5 (Cs) mutation suppresses secY24, indicating that inactivation of nusB causes cold-sensitive cell growth as well as phenotypic suppression of secY24. The correct map position of nusB is 9.5 min rather than 11 min as previously assigned. It is located at the distal end of an operon that contains a gene showing significant homology with a Bacillus subtilis gene involved in riboflavin biosynthesis.


A defined amino acid exchange close to the putative nucleotide binding site is responsible for an oxygen-tolerant variant of the Rhizobium meliloti NifA protein. In Rhizobium meliloti the NifA protein plays a central role in the expression of genes involved in nitrogen fixation. The R. meliloti NifA protein has been found to be oxygen sensitive and therefore acts as a transcriptional activator only under microaerobic conditions. In order to generate oxygen-tolerant variants of the NifA protein a plasmid carrying the R. meliloti nifA gene was mutagenized in vitro with hydroxylamine. About 70 mutated nifA genes were isolated which mediated up to 12-fold increased NifA activity at high oxygen concentrations. A cloning procedure involving the combination of DNA fragments from mutated and wild-type nifA genes allowed mapping of the mutation sites within the central part of the nifA gene. For 17 mutated nifA genes the exact mutation sites were determined by DNA sequence analysis. It was found that all 17 mutated nifA genes carried identical guanosine--adenosine mutations resulting in a methionine--isoleucine exchange (M217I) near the putative nucleotide binding site within the central domain. Secondary structure predictions indicated that the conformation of the putative nucleotide binding site may be altered in the oxygen-tolerant NifA proteins. A model is proposed which assumes that at high oxygen concentrations the loss of activity of the R. meliloti NifA protein is due to a conformational change in the nucleotide binding site that may abolish binding or hydrolysis of the nucleotide. Such a conformational change may be blocked in the oxygen-tolerant NifA protein, thus allowing interaction with the nucleotide at high oxygen concentrations.


Characterization and nucleotide sequence of the oriT-traM-finP region of the IncFVII plasmid pSU233. By hybridizing the IncFVII haemolytic plasmid pSU233 with a probe containing the origin of transfer of the IncFII plasmid R1, we isolated a 1.9 kb BglII fragment containing at least the origin of transfer (oriT), and the genes traM and finP. Functional complementation analysis of deletion derivatives was used to map the origin of transfer. We also determined the nucleotide sequence of traM and finP. Comparison with similar regions of several plasmids, also belonging to the Rep-FIIA family, revelaed that pSU233 resembles the F plasmid by very close. The homology is not evenly distributed along this region, but clustered into homologous regions (TraZb-oriT, TraMb-oriT and traM separated by non-homologous regions (TraYb-oriT, finP). This organization resembles that reported for the replication region and also suggests evolution by exchange of modules. In addition, the nucleotide sequence of finP is different from those previously described for other IncF plasmids and constitutes a new allele, which we have denominated allele VI.


Mutations in the cdc10 start gene of Schizosaccharomyces pombe implicate the region of homology between cdc10 and SWI6 as important for p85cdc10 function. The cdc10 gene of the fission yeast Schizosaccharomyces pombe is required for traverse of start and commitment to the mitotic cell division cycle rather than other fates. The product of the gene, p85cdc10, is a component of a factor that is thought to be involved in regulating the transcription of genes that are required for DNA synthesis. In order to define regions of the p85cdc10 protein that are important for its function a fine structure genetic map of the cdc10 gene was derived and the sequences of 13 cdc10ts mutants determined. The 13 mutants tested define eight alleles. Eleven of the mutants are located in the region that contains the two copies of the cdc10/SWI6 repeat motif, implicating it as important for p85cdc10 function.


Sugarbeet minicircular mitochondrial DNAs: high-resolution transcript mapping, transcript abundance and copy number determination. Three minicircular mitochondrial DNAs have been studied to address several aspects of transcription in sugarbeet mitochondria. High-resolution transcript mapping experiments have shown that sequences at the 5' termini of minicircle transcripts are highly homologous and resemble sequences at the 5' termini of sugarbeet mainband mitochondrial genes (atpA, atp6). In addition, they show homology to transcript termini of mitochondrial genes from other dicotyledonous plants, suggesting they may function as promoter sequences. Conserved sequences, which most probably act as RNA processing signals, were also identified at the 3' termini of minicircle transcripts. An oligonucleotide probe to a 14 base conserved sequence was used to determine the relative copy numbers of the three minicircle components in male-fertile mitochondria. Copy numbers were roughly equivalent, suggesting minicircles are replicated and/or transmitted with nearly equal efficiency, at least in sugarbeet taproots. Mc.a and Mc.c transcript levels are equivalent, consistent with their template copy number, however; Mc.d transcript levels were significantly lower than expected, implicating additional factors such as promoter strength and/or transcript stability in determining transcript levels in sugarbeet mitochondria, as recently demonstrated in maize.


Molecular cloning, characterization and purification of ornithine carbamoyltransferase from Mycobacterium bovis BCG. A genomic library of Mycobacterium bovis BCG has been constructed by cloning DNA partially digested with Sau3A into the Escherichia coli expression vector pAS1. The gene coding for ornithine carbamoyl-transferase (EC.2.1.3.3; OTCase), hereafter referred to as argF, was isolated from the library by complementation of a double argF-argI mutant of E. coli and its sequence was determined. The translation initiation codon used, GTG, was identified by comparing the amino acid sequence deduced from the gene with the N-terminal sequence of the corresponding purified protein. On this basis, the M. bovis BCG OTCase monomer consists of 307 amino acid residues and displays about 44% identity with other OTCases, the most closely related homologue being the anabolic enzyme of Pseudomonas aeruginosa. The native enzyme has an estimated molecular mass of 110 kDa, suggesting a trimeric structure as is the case for most of the anabolic OTCases known from various organisms.