Pregnancy-associated plasma protein-A2 levels are increased in early-pregnancy gestational diabetes: a novel biomarker for early risk estimation

AIM

To determine whether pregnancy-associated plasma protein-A2 levels are increased in early pregnancies complicated by gestational diabetes and whether gestation age influences levels. The possible use of pregnancy-associated plasma protein-A2 as a pre-screening biomarker to reduce the need for performing oral glucose tolerance tests in pregnant women was also investigated.

METHODS

Pregnant women were diagnosed with gestational diabetes in early pregnancy after a 2-hour 75 g oral glucose tolerance test in the catchment area of Skåne University Hospital, Lund, Sweden during 2011-2015 (n = 99). Age- and BMI-matched pregnant women without diabetes were recruited at similar gestational ages from maternal healthcare centres in the same geographical area during 2014-2015 to act as controls (n = 100). Circulating pregnancy-associated plasma protein-A2 was analysed in participant serum using commercially available enzyme-linked immunosorbent assay kits.

RESULTS

Circulating pregnancy-associated plasma protein-A2 was increased in women diagnosed with gestational diabetes [13.5 (9.58-18.8) ng/ml] compared with controls [8.11 (5.74-11.3) ng/ml; P < 0.001]. Pregnancy-associated plasma protein-A2 was associated with gestational diabetes independent of age, BMI, C-peptide and adiponectin (P < 0.001). Pregnancy-associated plasma protein-A2 as a pre-screening biomarker to identify women at a decreased risk of gestational diabetes resulted in a negative predictive value of 99.7%, with a sensitivity of 96% and a specificity of 30% at a cut-off level of 6 ng/ml.

CONCLUSIONS

This is the first study to show increased pregnancy-associated plasma protein-A2 levels in gestational diabetes. Pregnancy-associated plasma protein-A2 also shows promise as a pre-screening biomarker with the potential to reduce the need for performing oral glucose tolerance tests in early pregnancy. Future prospective cohort studies in a larger group of both high- and low-risk women are, however, needed to further confirm this observation.

Skim milk powder with high content of Maillard reaction products affect weight gain, organ development and intestinal inflammation in early life in rats

BACKGROUND

The intestinal tract is important for development of immune tolerance and disturbances are suggested to trigger autoimmune disorders. The aim of this study was to explore the effect of Maillard products in skim milk powder obtained after long storage, compared to fresh skim milk powder.

METHODS

Young rats were weaned onto a diet based on skim milk powder with high concentration of Maillard products (HM-SM, n = 18) or low (C-SM, n = 18) for one week or four weeks. Weekly body weight and feed consumption were noted. At the end, organ weights, intestinal histology, permeability and inflammatory cytokines were evaluated.

RESULTS

Rats fed with HM-SM had after one week, 15% less weight gain than controls, despite equal feed intake. After one week thymus and spleen were smaller, intestinal mucosa thickness was increased and acute inflammatory cytokines (IL-17, IL-1β, MCP-1) were elevated. After four weeks, cytokines associated with chronic intestinal inflammation (fractalkine, IP-10, leptin, LIX, MIP-2, RANTES and VEGF) were increased in rats fed with HM-SM compared to C-SM.

CONCLUSION

High content of Maillard products in stored milk powder caused an intestinal inflammation. Whether this is relevant for tolerance development and future autoimmune diseases remains to be explored.

Prevalence of zinc transporter 8 antibodies in gestational diabetes mellitus

AIMS

Gestational diabetes mellitus affects approximately 7% of all pregnant women. Some of these women develop autoantibodies that are generally characteristic of Type 1 diabetes. Autoantibodies targeting glutamic acid decarboxylase and tyrosine phosphatase-like protein are the most frequently reported. A recently identified autoantigen in Type 1 diabetes is zinc transporter 8. Some reports suggest that the frequency of zinc transporter 8 antibodies is as high as glutamic acid decarboxylase antibodies in Type 1 diabetes and thus a good diagnostic marker for autoimmune diabetes. There are currently no reports of zinc transporter 8 antibodies in gestational diabetes. The aim of this pilot study was to investigate the frequency of zinc transporter 8 antibodies in patients at clinical onset of gestational diabetes mellitus.

METHODS

  Subjects included in this pilot study were all diagnosed with gestational diabetes at Skåne University Hospital, Lund, Sweden, 2009-2010 (n = 193). Sera samples were analysed for antibodies using a commercial enzyme-linked immunosorbent assay according to the manufacturers' instructions.

RESULTS

We found that 19/193 patients with gestational diabetes, diagnosed in 2009-2010, were positive for at least one autoantibody. Glutamic acid decarboxylase was the most common single autoantibody (52.6%; 10/19), followed by zinc transporter 8 (21.1%; 4/19) and tyrosine phosphatase-like protein (15.8%; 3/19). Combinations of two or more antibodies were rare (10.5%; 2/19).

CONCLUSIONS

In this study, we found that zinc transporter 8 added 2.1% (4/193) of autoantibody positivity in women with gestational diabetes who were negative for glutamic acid decarboxylase and tyrosine phosphatase-like protein antibodies. Glutamic acid decarboxylase was still the most prevalent autoantibody in gestational diabetes, but, as zinc transporter 8 was present even in the absence of glutamic acid decarboxylase, this autoantibody could be an important independent marker of autoimmunity in gestational diabetes.

The glutamic acid decarboxylase 65 immunoglobulin G subclass profile differs between adult-onset type 1 diabetes and latent autoimmune diabetes in adults (LADA) up to 3 years after clinical onset

Autoantibodies against glutamic acid decarboxylase 65 (GADA) are found frequently in patients with autoimmune diabetes. Immunoglobulin (Ig)G(1) is the most frequent subclass among the GADA IgG subclasses. IgG(4) is a more common subclass in latent autoimmune diabetes in adults (LADA) at clinical onset compared to type 1 diabetes. The aim of this work was to study the different GADA-IgG subclass profiles during a 3-year follow-up in these groups of autoimmune diabetes. Adult-onset subjects, classified as either type 1 (n = 40) or LADA (n = 43), were included in the study. New samples were collected every year from these patients. In addition to conventional GADA analyses, GADA-IgG subclasses were also analysed with a radioimmunoprecipitation assay using biotin-conjugated antibodies (directed against human IgG subclasses and IgM) and streptavidin Sepharose. During 3 years' follow-up, all the IgG subclass levels decreased in type 1 diabetes - IgG(1): P < 0.001; IgG(2): P < 0.001; IgG(3): P < 0.001; IgG(4): P < 0.05 (Friedman's' test) - while levels remained stable for all four subclasses in LADA. GADA IgM, however, decreased in both groups (P < 0.001). Patients with LADA have higher GADA IgG(3) and IgG(4) at clinical onset and seem to maintain the levels and profile of their IgG subclasses up to 3 years after clinical onset, while all the GADA IgG subclass levels decrease in type 1 diabetic patients. This indicates a persistent different immune response in LADA compared to type 1 diabetes and further indicates the difference in pathogenesis.

Determination of glutamic acid decarboxylase antibodies (GADA) IgG subclasses − comparison of three immunoprecipitation assays (IPAs)

IgG subclasses of glutamic acid decarboxylase (GAD65) antibodies (GADA) may reflect the immunological state in the pancreas of GADA-positive patients with autoimmune diabetes. The use of biotin-conjugated antibodies and streptavidin Sepharose are used commonly in immunoprecipitation assays (IPA) based on 125I- or 35S-labelled antigens to capture IgG subclasses directed against IA-2 or GAD65. We have compared three different immunoprecipitation assays for the determination of GADA IgG subclasses. Two of the assays were based on the biotin and streptavidin systems provided in a solid (immobilized) or liquid (mobilized) phase binding environment. The third assay was based on N-hydroxysuccinimide (immobilized) interaction with primary amines (i.e. lysine residues) on the antibody. We found the liquid phase binding assay (LPBA) to be the most stable assay, with a comparatively low coefficient of variation and background.

Structural Insights into the Design of Nonpeptidic Isothiazolidinone-containing Inhibitors of Protein-tyrosine Phosphatase 1B

Structural analyses of the protein-tyrosine phosphatase 1B (PTP1B) active site and inhibitor complexes have aided in optimization of a peptide inhibitor containing the novel (S)-isothiazolidinone (IZD) phosphonate mimetic. Potency and permeability were simultaneously improved by replacing the polar peptidic backbone of the inhibitor with nonpeptidic moieties. The C-terminal primary amide was replaced with a benzimidazole ring, which hydrogen bonds to the carboxylate of Asp(48), and the N terminus of the peptide was replaced with an aryl sulfonamide, which hydrogen bonds to Asp(48) and the backbone NH of Arg(47) via a water molecule. Although both substituents retain the favorable hydrogen bonding network of the peptide scaffold, their aryl rings interact weakly with the protein. The aryl ring of benzimidazole is partially solvent exposed and only participates in van der Waals interactions with Phe(182) of the flap. The aryl ring of aryl sulfonamide adopts an unexpected conformation and only participates in intramolecular pi-stacking interactions with the benzimidazole ring. These results explain the flat SAR for substitutions on both rings and the reason why unsubstituted moieties were selected as candidates. Finally, substituents ortho to the IZD heterocycle on the aryl ring of the IZD-phenyl moiety bind in a small narrow site adjacent to the primary phosphate binding pocket. The crystal structure of an o-chloro derivative reveals that chlorine interacts extensively with residues in the small site. The structural insights that have led to the discovery of potent benzimidazole aryl sulfonamide o-substituted derivatives are discussed in detail.

Identification of ADAM10 as a major source of HER2 ectodomain sheddase activity in HER2 overexpressing breast cancer cells

Overexpression and activating mutations of ErbB family members have been implicated in the development and progression of a variety of tumor types. Cleavage of the HER2 receptor by an as yet unidentified ectodomain sheddase has been shown to liberate the HER2 extracellular domain (ECD) leaving a fragment with constitutive kinase activity that can provide ligand-independent growth and survival signals to the cell. This process is clinically relevant since HER2 ECD serum levels in metastatic breast cancer patients are associated with a poorer prognosis. Thus, inhibition of the HER2 sheddase may provide a novel therapeutic approach for breast cancer. We describe the use of transcriptional profiling, pharmacological and in vitro approaches to identify the major source of HER2 sheddase activity. Real-time PCR was used to identify those ADAM family members which were expressed in HER2 shedding cell lines. siRNAs that selectively inhibited ADAM10 expression reduced HER2 shedding. In addition, we profiled over 1000 small molecules for in vitro inhibition of a panel of ADAM and MMP proteins; a positive correlation was observed only between ADAM10 inhibition and reduction of HER2 ECD shedding in a cell based assay. Finally, in vitro studies demonstrate that in combination with low doses of Herceptin, selective ADAM10 inhibitors decrease proliferation in HER2 overexpressing cell lines while inhibitors, that do not inhibit ADAM10, have no impact. These results are consistent with ADAM10 being a major determinant of HER2 shedding, the inhibition of which, may provide a novel therapeutic approach for treating a variety of cancers with active HER2 signaling.

Structure-Based Design and Discovery of Protein Tyrosine Phosphatase Inhibitors Incorporating Novel Isothiazolidinone Heterocyclic Phosphotyrosine Mimetics

Structure-based design led to the discovery of novel (S)-isothiazolidinone ((S)-IZD) heterocyclic phosphotyrosine (pTyr) mimetics that when incorporated into dipeptides are exceptionally potent, competitive, and reversible inhibitors of protein tyrosine phosphatase 1B (PTP1B). The crystal structure of PTP1B in complex with our most potent inhibitor 12 revealed that the (S)-IZD heterocycle interacts extensively with the phosphate binding loop precisely as designed in silico. Our data provide strong evidence that the (S)-IZD is the most potent pTyr mimetic reported to date.

IgG4-subclass of glutamic acid decarboxylase antibody is more frequent in latent autoimmune diabetes in adults than in type 1 diabetes

AIMS/HYPOTHESIS

Glutamic acid decarboxylase autoantibodies (GADA) are the most frequent beta-cell-specific autoantibodies in type 1 diabetes and in latent autoimmune diabetes in adults (LADA). The autoimmune attack on pancreatic islet cells is associated with a T helper 1 cell (T(h)1) response, mainly represented by IgG(1)-subclass in humans. It has been proposed that the presence of IgG(4) may be associated with a T(h)2 response. The aim of our study was to compare the GADA IgG-subclass distribution between adult patients with type 1 diabetes and LADA.

METHODS

Patients with type 1 diabetes (n=45) and patients with LADA (n=60) were included. Radioimmunoprecipitation assay with IgG-subclass specific Sepharose (IgG(1), IgG(2), IgG(3) and IgG(4)) was used to precipitate the antibody/antigen-complex.

RESULTS

We only detected IgG(4)-subclass of GADA in subjects with LADA (26.7%; p<0.001). IgG(1) was the most common GADA-subclass in both groups, however IgG(1) as the solely expressed subclass was more common among type 1 diabetic patients (77.8%; p<0.05). The rank order of the frequencies of IgG-subclasses in type 1 diabetes was IgG(1)>IgG(3)>IgG(2)>IgG(4) and in LADA patients IgG(1)>IgG(4)>IgG(2)>IgG(3).

CONCLUSIONS/INTERPRETATION

The difference in GADA IgG-subclasses could indicate a different immune response, possibly an altered balance between T(h)1 and T(h)2 cytokine profile in pancreatic islets. This difference could contribute to the slower rate of beta cell destruction in LADA patients, as reflected by a higher C-peptide level at clinical onset.

Stress and dentistry: better practice through control

It's impossible to give a single definition to stress. That's because people experience it in different ways. It is possible, however, to get it and keep it under control. In fact, stress control is necessary to every successful dental practice.

Stress and dentistry: better practice through control

It's impossible to give a single definition to stress. That's because people experience it in different ways. It is possible, however, to get it and keep it under control. In fact stress control is necessary to every successful dental practice.

Outcome following stroke

A community study based on an age-stratified sample of those aged 55 years and older in a northern health district in the United Kingdom has been used to consider the implications for purchasing health-care services for those who have survived a stroke. The study showed that while almost a quarter of those reporting a stroke had made a full recovery, a wide range of impairments and disabilities persisted. Almost half reported needing help at least daily. A logistic regression model to predict this level of dependency found that impairments, disabilities and other factors, such as locality, were also predictive of dependency. A second model predicting mobility handicap (dwelling restricted) was found to have a similar mix of predictors. These results show how purchasers must consider the broad outcome in terms of a continuum of impairment, disability and handicap. The results also show that handicap is a distinct concept that draws together many influences which act upon the individual.

Prevalence of hip problems in the population aged 55 years and over: access to specialist care and future demand for hip arthroplasty

To determine the prevalence of hip problems in the population aged 55+, a postal questionnaire was sent to a multistage stratified random sample of residents of a health district with an over-55 population of 210,000. An initial four page postal questionnaire produced an 86% response rate from 18,827 eligible cases. A subsequent detailed questionnaire (with a response rate of 78%) then determined the prevalence of severe pain and severe disability amongst those with hip problems. The prevalence of those with existing hip replacements is estimated at 32.1/1000 (95% CI 29.5-34.9). An estimated 13.5/1000 (95% CI 12.4-14.7/1000) displayed levels of pain and disability consistent with a current need to consider arthroplasty. In addition, it appears that the over 75s are less likely to have access to appropriate surgery. Unless health authorities and, increasingly, general practitioners consider purchasing more hip replacements, the prevalence pool of those who could benefit will inexorably rise.

Are we making the most of the Stanford Health Assessment Questionnaire?

For many years, the Stanford Health Assessment Questionnaire (HAQ) has provided an effective measure of disability. Recently, some debate has emerged about whether or not the HAQ is an "ordinal' or "interval' scale. The opportunity to test its level of measurement arose when the scale was applied in a community survey which undertook a two-stage random sample using postal questionnaires to ascertain the health care needs of those with arthritis. The HAQ data are fitted to the Rasch model which tests for the presence of certain desirable characteristics of measurement, e.g. unidimensionality. The fit of the data to the model for those self-reporting rheumatoid arthritis (RA) was adequate. The transformed HAQ score, derived from the Rasch analysis, is compared with the ordinary HAQ (raw) score. This shows that, for those with RA, incremental units of the raw score at the margins of the scale reflect an increasing level of (dis)ability compared to similar units in the centre of the scale. Thus, the traditional HAQ score (range 0-3) is an ordinal score. The findings also indicate that scoring all 20 items may lead to greater sensitivity. Questions are also raised about the construct validity for those with other types of arthritis. For osteoarthrosis, the grip item does not appear to belong to the same underlying construct as the other items.

Prevalence of low back pain in the community: implications for service provision in Bradford, UK

STUDY OBJECTIVE

To assist a purchasing district in the planning of services for low back pain by assessing the prevalence of symptoms and the current involvement of primary, secondary, and complementary care in the treatment of low back pain. In the light of these findings, to assess further the potential impact of a new system of open access to physical therapy, as recommended by the British Clinical Standards Advisory Group (CSAG).

DESIGN

A two-stage cross sectional survey approach using postal questionnaires.

SUBJECTS

Altogether 1437 men and 1747 women aged 25-64 years, randomly selected from the family health services association register in Bradford.

MAIN RESULTS

An annual incidence of 4.7% for low back pain was found, with lifetime, 12 month period, and point prevalences of 59%, 39%, and 19% respectively. Over a one year period, 50.3% of episodes were acute (< 2 weeks), 21% were subacute (2 weeks-3 months), and 26% were chronic (over 3 months) in duration. Altogether 17.8% of the population in this age range experienced referred pain, numbness, or tingling, and 6.4% took time off work as a result of low back pain. In the same year, 20% of the population in the same age range consulted no-one about their pain, 13.7% were treated at the primary care level, 4% received secondary care, and 3% visited a complementary therapist. One fifth of those who did not consult a professional experienced severe pain during episodes. Prevalence estimates indicate that an emphasis on early intervention and primary care management of simple low back pain as recommended by the CSAG could generate a 131% surge in demand for physical therapy.

CONCLUSIONS

Local prevalence estimates may allow purchasers to estimate the potential effects of a shift in management policy for low back pain and to highlight areas of unmet need in terms of resources and patient education.

Prevalence of self reported stroke in a population in northern England

STUDY OBJECTIVE

The aim of this study was to determine the prevalence of stroke survivors in a health district population aged 55 years and over.

DESIGN

This was a point prevalence study using two-stage postal questionnaires sent to an age stratified random sample of the population.

SETTING

A district health authority in northern England with a resident population of 723,000.

SUBJECTS

Altogether 18,827 residents aged 55 years or over.

MAIN RESULTS

Prevalence was found to increase with age and, apart from the very elderly, males had a higher prevalence than females. Overall prevalence was found to be 46.8/1,000 (95% CI 42.5, 51.6). 23% of respondents reported full recovery from stroke. Cognitive impairments (33%), problems with lower limbs (33% for right leg; 27% for left leg) and speech difficulties (27%) were the most common residual impairments.

CONCLUSIONS

Current guidelines to purchasers on the provision of services to those who have had a stroke may under-estimate prevalence rates by as much as 50%. This could lead to a shortfall in provision of services designed to support people in the months and years following their stroke.

Stress and dentistry. Better practice through control

It's impossible to give a single definition to stress. That's because people experience it in different ways. It is possible, however, to get it and keep it under control. In fact stress-control is necessary to every successful dental practice.

Prevalence of knee problems in the population aged 55 years and over: identifying the need for knee arthroplasty

OBJECTIVE

To determine the prevalence of knee problems in people aged 55 years and over and identify those who should be considered for knee arthroplasty.

DESIGN

Postal survey; questionnaires were sent to a multistage stratified probability sample of residents of North Yorkshire Health Authority aged 55 and over.

SETTING

A health district with a population of 210,000 aged 55 and over.

RESULTS

An initial four page postal questionnaire produced an 86% response rate among 18,827 eligible patients. A subsequent detailed questionnaire sent to 1277 patients with knee problems (with a response rate of 78%) then determined the prevalence of severe pain and severe disability. Pain and disability consistent with the need to consider arthroplasty was found in 20.4/1000 (95% confidence interval 18.0 to 23.1); of these, 4.1 (2.7 to 5.8)/1000 had extreme disability. Age and sex specific rates in men who might benefit from arthroplasty were, in those aged 55-64, 12.9 (8.4 to 19.0)/1000; aged 65-74, 12.1 (7.4 to 18.4)/1000; aged 75 and over, 20.3 (12.9 to 30.5)/1000. In women aged 55-64 the rates were 12.9 (8.6 to 18.7)/1000; aged 65-74, 19.6 (13.9 to 26.7)/1000; aged 75 years and over, 42.6 (34.3 to 52.4)/1000.

CONCLUSIONS

Total knee replacement has until recently been considered unreliable and often seen as a last resort for many with severe knee problems. Advances in prosthesis design and surgical and anaesthetic techniques have transformed this procedure into a reliable option with a potential for reducing disability and dependency in a large number of people in the community. Understandably, the prevalence pool of those who may benefit is large; health authorities and, increasingly, general practitioners should consider purchasing more total knee replacement surgery to offer real choice to those in need.

Wheelchair wheels for use on sand

Mobility over sand and other rough surfaces can be a major problem for people in wheelchairs. From tests with a simple prototype, model tests and theoretical calculations the following observations were made for an attendant propelled chair. The rolling resistance of a wheelchair on sand may be improved by pulling, rather than pushing the chair. The use of a ball wheel at the front improves the rolling resistance, though standard large diameter rear wheels give acceptable performance. From these observations a prototype device for fitment to a standard wheelchair has been designed.

Evaluation of a robotic workstation for the disabled

Experience with potential users is vital at all stages of the design of equipment for the disabled, not least in the field of rehabilitation robotics. The development of a robotic workstation for the disabled has progressed, over a period of 6 years, from the use of a cheap educational arm, to a specially engineered robot arm and workstation. The design and specification has been refined through constant evaluation by disabled users. Trials at a spinal injuries unit have given approval to the design and appearance of the latest robot arm and workstation, and have led to modifications to the user interface and software. Further trials have taken place in a user's home to investigate in greater depth the usefulness of a robotic workstation in a practical situation. The results of these trials are presented. It is proposed to refine the design of the arm for low-volume production, easy maintenance in the field and improved appearance.

The lymphocyte transformation test with type II collagen as a diagnostic tool of autoimmune sensorineural hearing loss

Immunological disorders of the cellular type can be diagnosed by the lymphocyte transformation test (LTT). An autoimmune mechanism of certain cases of sensorineural hearing loss (SNHL) can be evaluated by using human inner ear tissue as an antigen. Recent studies have shown that type II collagen plays an important role, not only in some autoimmune mediated rheumatoid diseases, but also as an antigenic substrate of inner ear tissue in autoimmune sensorineural hearing loss. This paper deals with results of the lymphocyte transformation test using type II collagen as antigen in 68 patients with progressive sensorineural hearing loss (PSNHL) and 68 healthy volunteers. Thirty-four patients showed a strong stimulation in the lymphocyte transformation test, in contrast to only four volunteers in the control group, two of whom had a history of rheumatoid arthritis.

Undetectable caeruloplasmin values in a patient with autoimmune chronic active hepatitis

Caeruloplasmin is an alpha 2 protein produced in the liver that is responsible for transporting copper in the blood. Caeruloplasmin values are usually high in patients with chronic liver diseases, including chronic active hepatitis: low values, however, are characteristic of Wilson's disease. The case of a 17 year old woman with very low caeruloplasmin values and chronic active hepatitis of the lupoid type is described. Steroid treatment resulted in an increase in the caeruloplasmin concentration and clinical improvement.

The Public Library System: Social Services Resource for the Geriatric Population

The public library system is targeting the geriatric population and instituting programs to meet informational and recreational needs. From retirement planning, visual aids, and screening, to accessing library material to the elderly, the public library system attempts to meet the challenge of providing service to this special population. Although not a formal group, the library has inherent therapeutic effects that benefit the elderly who participate in their programs. The clinician would be advised to take advantage of these various programs. Because each local and regional center will offer different programs, calling a local library is the most effective way to find out what a specific public library system has to offer. Nurses may also consider joint efforts to initiate programs in their library systems to better meet the population's needs.

Elevated creatine phosphokinase and creatine phosphokinase-MB in acute laryngitis

Elevated creatine phosphokinase (684 mU/ml) and creatine phosphokinase-MB (3.5%, 23.9 mU/ml) were observed in a 66 year old female with acute laryngitis. The patient had received L-thyroxine because of hypothyroidism for 10 years and her T3 and TSH levels were normal. Acute myocardial infarction was denied by repeated EKG findings. The mechanisms of the enzyme abnormality were discussed.

Effects of doxorubicin on the sensitivity of L1210 leukemia cells to deformation-associated trauma

Most of the cancer cells arrested in the microcirculation during hematogenous metastasis are rapidly killed; one major mechanism is surface-membrane rupture, associated with the mechanical deformation of cancer cells in capillaries. The feasibility of increasing the susceptibility of cancer cells to lethal, deformation-associated trauma by doxorubicin, was tested in an in vitro mechanical model system, by filtering suspensions of L1210 leukemia cells through 8-microns pore-size Nuclepore membranes, with or without prior incubation with 10(-7)M doxorubicin. The results showed that mechanically-induced loss of cancer cells immediately after filtration was increased from 18 to 55% in cells previously exposed to doxorubicin for 48 h. The results indicate the feasibility of chemotherapeutic enhancement of the mechanical killing-action of the microvasculature as a potential rate-regulator of hematogenous metastasis.

Vasculitis and cryoglobulinemia associated with persisting cholestatic hepatitis A virus infection

Extrahepatic manifestations are rarely found in hepatitis A viral (HAV) infection. Only a single case of HAV infection associated with cutaneous vasculitis and cryoglobulinemia has been reported. Described here is a patient with a persisting cholestatic type of HAV infection who developed cutaneous vasculitis and cryoglobulinemia during the third month of her illness. Analysis of the cryoglobulins revealed IgM anti-HAV antibodies.

Antitumor properties of tetrahydrobenz[a]anthraquinone derivatives

The compound 8,11-bis[[2-[(2-hydroxyethyl)amino]ethyl]amino]- 6-methoxy-1,2,3,4-tetrahydro-7,12-benz[a]-anthraquinone (7) was synthesized from 3,6-dimethoxyphthalic anhydride and 6-methoxy-1,2,3,4-tetrahydronaphthalene by a Friedel-Crafts reaction, cyclization to form a dihydroxyanthraquinone, and conversion into the amino-substituted derivative by reaction with 2-[(2-hydroxyethyl)amino]ethylamine. The new compound, a ring D analogue of mitoxantrone, showed growth inhibition, at micromolar concentrations, of murine leukemia 1210, human lung H125, human breast MCF7, human ovary 121, and human colon WiDr and increased the life span of leukemic mice by 38%.

A 15-kD interferon-induced protein and its 17-kD precursor: expression in Escherichia coli, purification, and characterization

Using recombinant DNA technology, a 15-kD interferon (IFN)-induced protein and its 17-kD precursor have been expressed in Escherichia coli to obtain sufficient quantities of each protein for the investigation of their biological roles. Both the 15-kD and 17-kD proteins have been purified to homogeneity and crystallized. The recombinant 15-kD protein has an identical reversed-phase HPLC elution profile to that of the native 15-kD protein purified from human cells. Furthermore, the recombinant 15-kD and 17-kD proteins have identical amino- and carboxy-terminal amino acid sequences to those predicted from the DNA sequence. The native and recombinant 15-kD proteins give identical tryptic peptide maps, and the recombinant 17-kD protein gives only one additional tryptic peptide. We conclude that the recombinant 17-kD and 15-kD proteins are identical to the 17-kD precursor and the 15-kD stable product synthesized in human cells in response to IFN stimulation. In addition, we have demonstrated that the recombinant 17-kD precursor protein can be converted to the 15-kD protein by cytoplasmic extracts of human cells.

A 15-kDa interferon-induced protein is derived by COOH-terminal processing of a 17-kDa precursor

An interferon-induced 15-kDa protein is synthesized from a precursor of higher molecular weight; the precursor contains 165 amino acids (17 kDa), whereas the stable product (15 kDa) contains 156 amino acids. The stable 15-kDa form is derived from the precursor 17-kDa form by the removal of eight amino acids from the COOH terminus and the methionine from the NH2 terminus. The existence of the precursor 17-kDa protein can be demonstrated after brief periods of in vivo labeling with [35S]methionine and by translation of mRNA in vitro.

Relevance of specific activity in experimental erythrocytocide by 55Fe

Iron loads between 0.20 microgram and 26 microgram, added to 5 mu Ci 59Fe, were followed for up to 150 days in mice. Relative organ uptake increased as a function of iron load in liver and kidneys while it decreased in bone marrow and blood. Several weeks after injection, all load-related differences disappeared.

Selective damage to erythroblasts by 55-Fe

The low energy and short range of 55-Fe Auger electrons were utilized in mice to deliver lethal intracellular radiation to iron-incorporating erythropoietic precursors with minimal radiation damage to other bone marrow cells. The ensuing intramedullary, selective erythropoietic death was demonstrated by absolute and differential bone marrow cell counts and by decreased blood uptake of 59-Fe. The decreased number of colony-forming units in spleen colony assay and the decreased ability of tranplanted bone marrow to protect fatally irradiated mice shows that the bone marrow was partially depleted of pluripotent stem cells. These data are interpreted to indicate an increased pluripotent stem cell utilization in response to increased demand for differentiation of stem cells along the erythropoietic pathway.