Intracellular cysteine delivery system that protects against toxicity by promoting glutathione synthesis.

Depletion of glutathione by inhibition of its synthesis by buthionine sulfoximine, an irreversible inhibitor of gamma-glutamylcysteine synthetase, leads to increased sensitivity to (i) irradiation and (ii) oxidative stress. In the present work, an intracellular cysteine delivery system was used to promote glutathione synthesis, and this was found to protect against toxicity. Thus, administration of L-2-oxothiazolidine-4-carboxylate protected against acetaminophen toxicity in mice; the thiazolidine, which is converted to L-cysteine by the enzyme 5-oxo-L-prolinase (present in many animal tissues and in plants) promotes the synthesis of glutathione, which is the actual protectant. The effect of this thiazolidine in increasing the level of glutathione is prevented by administration of buthionine sulfoximine. This thiazolidine may be useful in the treatment of other toxicities and in the treatment of certain diseases. It may also be valuable as a component of amino acid mixtures used in therapy and as a safener in agriculture.     

Hyperthermic intraperitoneal chemoperfusion is an option for treatment of peritoneal carcinomatosis in children

Background

Gastrointestinal carcinomas in childhood are rare and frequently present at an advanced stage. Besides lymphatic and distant organ metastasis, peritoneal carcinomatosis may be detected and has a poor prognosis. In addition to surgery and intravenous chemotherapy, hyperthermic intraperitoneal chemoperfusion (HIPEC) may be an option for selected patients. Our aim was to demonstrate the feasibility of the method and to discuss possible indications.

Methods

After treating a series of adult patients, HIPEC for peritoneal carcinomatosis from a signet cell carcinoma of the colon was performed intraoperatively in a 12-year-old boy. We gave mitomycin C at a dose of 30 mg/m² over 90 minutes at maximum temperature of 41.2°C. We performed intraoperative drug level monitoring and daily postoperative liver and kidney function tests and differential blood counts.

Results

Hyperthermic intraperitoneal chemoperfusion was performed according to protocol without complications. Perfusate and venous drug levels were similar to those in an adult case. The patient had an uneventful recovery, and serum chemistry and blood count returned to normal after a week. The boy lived for 36 months after initial presentation. Sixteen months after HIPEC, still with excellent quality of life, an elevated carcinoembryonic antigen (CEA) indicated recurrence. Thirty months after HIPEC, he died of progressive recurrent disease.

Conclusions

Hyperthermic intraperitoneal chemoperfusion as performed in adults may be beneficial to children with peritoneal carcinomatosis and merits further study.     

Häufigkeit und prognostische Bedeutung von epitheloidzelligen Reaktionen und Mikrokarzinosen in den regionären Lymphknoten beim Magenkarzinom

Zusammenfassung An 113 Patienten mit Adenokarzinom des Magens (pT1–3, pN0–1, pM0, R0) wurden die H?ufigkeit und prognostische Bedeutung von Epitheloidzellreaktionen und der Mikrokarzinose in region?ren Lymphknoten untersucht. Die statistische Analyse erfolgte multivariat nach dem Cox-Regressionsmodell in Abh?ngigkeit vom Tumorstadium, Differenzierungsgrad und der Laurén-Klassifikation. Epitheloidzellreaktionen wurden in 34 % der F?lle beobachtet (n = 113) und waren hinsichtlich prognostischen Verlauf, Tumortyp, Differenzierungsgrad oder Tumorstadium ohne Einflu?; ihr Auftreten erlaubte keinen Rückschlu? auf das Bestehen einer Mikrokarzinose oder Metastase. Bei 90 % der pN0-F?lle wurde immunhistochemisch eine Mikrokarzinose (definiert als Tumoreinzelzellen oder -zellgruppen in Sinus oder Pulpa der Lymphknoten ohne umgebende Stromareaktion) nachgewiesen. Waren mehr als 10 % aller untersuchten Lymphknoten eines Falles mit ≥ 3 Tumoreinzelzellen pro Lymphknotenschnitt befallen, so kam es zu einer signifikanten Prognoseverschlechterung. Bei der Mikrokarzinose ist demnach die Anzahl sowohl der Tumorzellen wie auch der befallenen Lymphknoten von prognostischer Bedeutung. Bei 97 % der pN1-F?lle fand sich zus?tzlich zu den Metastasen eine Mikrokarzinose. Hierbei zeigte sich jedoch kein zus?tzlicher prognostischer Einflu? der Mikrokarzinose.      

Polylactones, 24. Polymerizations of racemic and meso-D,L-lactide with Al?O initiators. Analyses of stereosequences

Racemic D ,L -lactide and meso-D ,L -lactide were polymerized with four different initiators: Al(isopropoxide)₃, AIEt₃/neopentyl alcohol (1 : 1, mole ratio), AIEt₃/(+)-menthol (1 : 1, mole ratio) and methylaumoxane. Most polymerizations were conducted in xylene at 60, 90 and 120°C, but at 60°C the yields were below 10%. ¹H NMR end-group analyses revealed the formation of alkyl ester end-groups from all Al-alkoxide initiators, in agreement with an insertion mechanism. The highest molecular weights were obtained with the methylalumoxane initiator. The stereosequences of the isolated poly(D ,L -lactide)s were analyzed by ¹H and ¹³C NMR spectroscopy on the basis of tetrad effects. poly(D ,L -Iactide)s prepared from racemic D ,L -lactide suggest a stereospecific polymerization favoring syndiotactic growing steps. In the case of meso-D ,L -lactide all polymerizations follow Bernoullian statistics. Transesterification is poor or absent at temperatures ≤ 120°C. However, random stereosequences may be obtained by bulk polymerizations at 180°C. DSC measurements revealed that the glass transition temperature mainly depends on the molecular weight and not on slight differences in the stereosequences.     

Catfish antibodies to blood group substances: I. Response of the Australian freshwater catfish, Tandanus tandanus (Mitchell), to the injection of human A, B and H secretor materials

Injection of Australian freshwater catfish, Tandanus tandanus (Mitchell), with human ABH secretor fluids mixed with adjuvant, resulted in the production by these fish of potent ABH specific haemagglutinating and precipitating antisera. No ABH haemagglutinins or precipitins were produced by catfish injected with non-secretor fluids.

Fractionation of the agglutinins by absorption, together with immunodiffusion studies, revealed that in most cases, the predominant response was an anti-H response. However, in some fish injected with B or A₁B secretor salivas, high titres of cross-reacting A and B agglutinins were formed.

The nature of the ABH agglutinin response in these fish is discussed with particular reference to three points. (1) The specificities of the ABH agglutinins formed. (2) The possibility that the variety and magnitude of the response are under some form of genetic control. (3) The possibility of the production in Australian freshwater catfish of anti-carbohydrate antibodies of limited heterogeneity.

     

Common Specificities of Auto- and Iso-Antibodies to Human Spermatozoa

ABSTRACT: The specificities of antispermatozoal antibodies in humans were compared using the ability of F(ab')2 fragments prepared from sera containing spermatozoal antibodies to block access to antigenic sites on spermatozoa. Reciprocal blocking experiments were carried out on a panel of 13 sera which came from both men and women, had different modes of agglutination, and came from widely separated population centers. The blocking experiments confirmed that specificities of antispermatozoal antibodies bear little relation to those suggested by observed modes of agglutination. F(ab')2 fragments from head-agglutinating sera could inhibit the immobilizing activity of a tail-agglutinating sera and vice versa. Similarly, the sera from men and women could inhibit each other, as could sera collected from patients living in widely separated localities. It is concluded that there are more than one, but a limited number, of antigens on the spermatozoal surface capable of generating antibodies with antifertility effects. It is also concluded that these antigens occur all over the sperm surface but may be concentrated in certain areas and that the observed modes of agglutination depend at least as much on the characteristics of the antibodies as on their specificities.     

Point-of-Care Glucose and Lipid Profile Measures Using a Human Point-of-Care Device in Mouse Models of Type 2 Diabetes Mellitus,Aging, and Alzheimer Disease

A point-of-care (POC) device to measure mouse glucose and lipid profiles is an important unmet need for cost-effective, immediate decision making in research. We compared metabolic analyte profiles obtained using a human clinical POC device with those from a veterinary laboratory chemical analyzer (LCA). Unfasted terminal blood samples were obtained by cardiac puncture from C57Bl/6J mice used in a diet-induced obesity model of type 2 diabetes mellitus; age-matched C57Bl/6J controls; a transgenic mouse model of Alzheimer’s disease on a C57BL/6J background (16 wk old); and aged C57BL/6J mice (24 to 60 wk old). Aliquots of the blood were immediately assayed onsite using the POC device. Corresponding serum aliquots were sent analyzed by LCA. Measures from the POC and LCA devices were compared by using the Bland–Altman and Passing–Bablok methods. Of a total of 40 aliquots, LCA results were within reported reference ranges for each model. POC results that fell beyond the device range were excluded from the analyses. The coefficient of determination and Passing–Bablok analysis demonstrated that POC glucose and HDL had the best agreement with LCA. The Bland–Altman analysis found no value-dependent bias in glucose and no significant bias in HDL. The remaining lipid analytes (cholesterol and triglyceride) showed significant bias. Until an improved, validated mouse POC device with lipid profile capability is available, the POC device that we tested appears adequate for screening glucose and HDL in mouse blood. Disadvantages of this clinical POC device are the narrow human ranges relative to ranges found in mice and its limited precision as compared with the LCA. This study demonstrates that when the samples are within the device range limits, this human POC device can accurately track metabolic syndrome and be used to compare patterns in glucose and HDL.

During the last few decades, clinical point-of-care (POC) testing technology has been a fast-growing field with a variety of medical applications. The benefits of POC devices include streamlining the treatment process, reducing lab costs, and operating in low resource environments.¹³ In the domains of diagnostic testing and disorders requiring continuous monitoring, POC devices fill a gap in healthcare that provides better patient experiences and quality of care.Currently a limited number of POC devices have been designed for veterinary use,^9,16,23 and only a few of the available human clinical POC devices have been tested for accuracy when used in preclinical animal models.^10,16,22,23 The ability to conduct a POC analysis for type 2 diabetes mellitus (T2DM) and aging mice would provide several benefits to animal research, including diagnostic test convenience and immediate results. POC testing requires only a small blood volume of 5 to 40 µL, thus simplifying the blood collection process and allowing repeated and frequent sampling from each subject. Finally, use of POC devices provides a less costly alternative to the cost of a laboratory clinical analyzer (LCA) or a contract with a commercial veterinary laboratory. Within the past few years, several POC devices for human use have been modified and further developed to become self-testing devices for blood oxygen, continuous glucose monitoring, lipid profile or analytes such as lactate, creatinine, cholesterol, uric acid, hemoglobin, and illicit drugs.^4,21 However, none of these extended POC devices have been assessed for use in mice.Our laboratory studies mouse metabolic models of T2DM, aging, and Alzheimer disease (AD). To track diabetes severity and determine on the onset of a metabolic syndrome, the mice undergo frequent longitudinal glucose and lipid profile screening, which requires methodologies that require a very small blood sample for each draw.⁷ The present pilot study evaluates a recently developed human POC device that can measure glucose and a full lipid profile for its utility in mice. Groups of mice with normal and abnormal glucose and lipid profiles were used to test the full range of potential results. Our analysis compares values obtained with the POC device and with a veterinary LCA (as a ‘gold standard’).