Restoration of thrombolytic potential in plasminogen-deficient mice by bolus administration of plasminogen

Homozygous plasminogen-deficient (Plg-/-) mice had a significantly reduced thrombolytic capacity toward intravenously injected 125I-fibrin labeled plasma clots prepared from Plg-/- murine plasma (9% +/- 3% lysis after 8 hours; (mean +/- SEM, n = 6), as compared with 82% +/- 8% in wild-type mice; P < .0001). Bolus injection of 1 mg purified murine plasminogen in 10- to 17-week-old Plg-/- mice increased the plasminogen antigen and activity levels at 8 hours to normal levels (130 +/- 5 micrograms/mL). Plasminogen administration was associated with significant restoration of thrombolytic potential (64% +/- 7% spontaneous clot lysis; P < .0001 versus lysis without plasminogen injection). Bolus injection of 1 mg plasminogen in homozygous tissue- type plasminogen activator-deficient (t-PA-/-) mice doubled the plasminogen antigen and activity levels after 8 hours and increased 125I-fibrin clot lysis at 8 hours from 13% +/- 3% to 34% +/- 5% (P = .008). Fibrinogen, t-PA antigen and alpha 2-antiplasmin activity levels after 8 hours were not significantly different in the groups with or without plasminogen injection. Injection of plasminogen induced a variable increase (on average 7- to 10-fold) of PAI-1, but no correlation with the extent of spontaneous clot lysis was observed. Histopathologic examination at the end of the experiments revealed that fibrin deposition in the liver of Plg-/- mice was slightly reduced 8 hours after bolus plasminogen injection (P = .007) and markedly reduced after 24 hours (P < .0001). Plasminogen antigen levels in liver extracts were comparable with those found in wild-type mice at 8 hours (130 +/- 20 versus 110 +/- 15 ng/mg protein) and decreased to 25 +/- 3.2 ng/mg protein at 24 hours. Thus, restoration of normal plasminogen levels in Plg-/- mice normalized the thrombolytic potential toward experimentally induced pulmonary emboli, and resulted in removal of endogenous fibrin deposits within 24 hours.     

Immunotherapy in gastric cancer

Gastric cancer is the second most common of cancerrelated deaths worldwide.In the majority of cases gastric cancer is advanced at diagnosis and although medical and surgical treatments have improved,survival rates remain poor.Cancer immunotherapy has emerged as a powerful and promising clinical approach for treatment of cancer and has shown major success in breast cancer,prostate cancer and melanoma.Here,we provide an overview of concepts of modern cancer immunotherapy including the theory,current approaches,remaining hurdles to be overcome,and the future prospect of cancer immunotherapy in the treatment of gastric cancer.Adaptive cell therapies,cancer vaccines,gene therapies,monoclonal antibody therapies have all been used with some initial successes in gastric cancer.However,to date the results in gastric cancer have been disappointing as current approaches often do not stimulate immunity efficiently allowing tumors continue to grow despite the presence of a measurable immune response.Here,we discuss the identification of targets for immunotherapy and the role of biomarkers in prospectively identifying appropriate subjects or immunotherapy.We also discuss the molecular mechanisms by which tumor cells escape host immunosurveillance and produce an immunosuppressive tumor microenvironment.We show how advances have provided tools for overcoming the mechanisms of immunosuppression including the use of monoclonal antibodies to block negative regulators normally expressed on the surface of T cells which limit activation and proliferation of cytotoxic T cells.Immunotherapy has greatly improved and is becoming an important factor in such fields as medical care and welfare for human being.Progress has been rapid ensuring that the future of immunotherapy for gastric cancer is bright.     

History of Helicobacter pylori,duodenal ulcer,gastric ulcer and gastric cancer

Helicobacter pylori(H.pylori)infection underlies gastric ulcer disease,gastric cancer and duodenal ulcer disease.The disease expression reflects the pattern and extent of gastritis/gastric atrophy(i.e.,duodenal ulcer with non-atrophic and gastric ulcer and gastric cancer with atrophic gastritis).Gastric and duodenal ulcers and gastric cancer have been known for thousands of years.Ulcers are generally non-fatal and until the 20th century were difficult to diagnose.However,the presence and pattern of gastritis in past civilizations can be deduced based on the diseases present.It has been suggested that gastric ulcer and duodenal ulcer both arose or became more frequent in Europe in the 19th century.Here,we show that gastric cancer and gastric ulcer were present throughout the 17th to 19th centuries consistent with atrophic gastritis being the predominant pattern,as it proved to be when it could be examined directly in the late 19th century.The environment before the 20th century favored acquisition of H.pylori infection and atrophic gastritis(e.g.,poor sanitation and standards of living,seasonal diets poor in fresh fruits and vegetables,especially in winter,vitamin deficiencies,and frequent febrile infections in childhood).The latter part of the 19th century saw improvements in standards of living,sanitation,and diets with a corresponding decrease in rate of development of atrophic gastritis allowing duodenal ulcers to become more prominent.In the early 20th century physician’s believed they could diagnose ulcers clinically and that the diagnosis required hospitalization for"surgical disease"or for"Sippy"diets.We show that while H.pylori remained common and virulent in Europe and the United States,environmental changes resulted in changes of the pattern of gastritis producing a change in the manifestations of H.pylori infections and subsequently to a rapid decline in transmission and a rapid decline in all H.pylori-related diseases.     

Early amniocentesis for prenatal cytogenetic evaluation

Early amniocentesis at 11-14 weeks gestation was evaluated in 100 consecutive patients to see how this technique compares with later amniocentesis. There were no complications as a consequence of the procedure or related pregnancy losses of chromosomally normal fetuses. Samples obtained from three (3%) patients showed insufficient cell growth; two of these patients elected a repeat procedure, which yielded a normal karyotype in each case. There were five abnormal karyotypes, one of which was a culture artifact; in the latter case, repeat amniocentesis at 15 weeks yielded a normal result. Of the 95 pregnancies with normal karyotypes, 94 were progressing normally at follow-up, and one patient elected pregnancy termination because of maternal indications. It appears that early amniocentesis may be an attractive alternative to traditional amniocentesis, in that it provides results at an earlier gestational age and may avoid certain disadvantages of chorionic villus sampling.     

Neurological disorders in Nigerian Africans: a community-based study

In a Nigerian town with a stable population of 20,000, a door-to-door survey was conducted, using a questionnaire involving a complete census and a simple neurological evaluation which had previously showed a 95% sensitivity and an 80% specificity for detecting neurological disease. Positive responders were evaluated and categorised, using agreed criteria for diagnoses. Nearly 100% cooperation was obtained. Life prevalence ratio for at least one episode of headache was 51/1000. Crude point prevalence ratio for migrainous headache was 5.3/100, and peak age-specific ratio was in the first decade. Prevalence ratio for epilepsy was 533/100,000 and peak age-specific prevalence ratio occurred in the 5-14 years age groups. The prevalence ratio for peripheral nerve disorders was 268/100,000, and age-specific prevalence ratio for tropical neuropathy increased with age. Prevalence ratio for stroke was rather low at 58/100,000, but was probably due to the people's attitude to the disabled elderly and high mortality of stroke which showed annual mortality rate of 70/100,000 which increased with age to 1519/100,000 per year in the eighth decade. Crude prevalence ratios (cases per 100,000) for others are 112 for neurological complications (including sciatica) of spondylosis, 15 each for poliomyelitis, motor neurone disease, development speech disorders, 10 each for syncope, hereditary neuropathies. Parkinson's disease, benign essential tremor, primary cerebellar degeneration, cerebral palsy, mental retardation, organic psychosis (probable intracranial tumor) and 5 each for muscular dystrophy, pyomyositis, spina bifida occulta, alcohol dependence and cerebral malaria. The implications of the findings are important for development of community neurological services in the developing countries.     

Measurement of vasoactivity in the guinea-pig choroid

Purpose: A perfusion system for studying the vasoactive properties of the guinea-pig choroid is described. Methods :The principle of operation is that the vascular resistance of the entire vascular network of an isolated, perfused eye can be monitored by recording the pressure required to deliver a constant flow of perfusate through the network. Delivery of the pharmacological agent of interest into the perfusate stream and the subsequent determination of the magnitude of any induced pressure changes allows the vasoactive potency of various agonists to be assessed. Results: The baseline vascular resistance was 1.35 ± 0.16 mmHg. min/μL (mean ± SEM; n=10) and the mean response to intraluminal delivery of 124 mmol/L K⁺ Krebs was an increase in resistance of 297±67%. Vasoactive responses were sustainable for more than 8 h. Conclusions: This system will now be used to study the vasoactive properties of the guinea-pig choroid in greater detail.