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B Martin

Publications and source records attributed to B Martin.

At least 325 records · Page 18Linked to original sources
PubMed1987

A receptor binding assay for endoxin in human urine.

Endoxin is an endogenous substance known to participate in the regulation of the sodium balance and hypertension. Its chemical nature remains elusive. Based on its capacity to specifically bind to Na-K ATPase receptors we describe a receptor assay for its measurement in human urine. The endoxin was extracted by methanol and desalted on a silicagel column with a mixture of chloroform-ethanol. Calibration curves have been established by the transformation of the weight of crude extract in actual content of active material expressed in nmol/l as calculated from Scatchard plots analysis. Normal values are given for subjects on regular salt diet. Changes in endoxin urinary elimination after an oral salt load are outlined.

Binding, Competitive↗
PubMed1987

Ultrasonography of the acute scrotum.

The acute scrotum remains a difficult clinical challenge because of numerous etiologies including inflammatory processes, testicular torsions, traumas, and tumors that can justify early surgery. Ultrasound study appears to be the imaging modality of choice to confirm the clinical assessment. We reviewed 825 scrotal scans performed with high-resolution scanners; 283 were considered pathologic and classified as follows: 27 tumors (9.5%), 21 traumas including torsions (7.4%), 142 infectious diseases (50.1%), 99 dystrophic diseases (29.2%), and 16 miscellaneous (5.6%). Acute scrotal pain was the only symptom in 83 cases (29.3%). In this paper, we emphasize the different roles of ultrasound depending on the initial clinical presentation, which determines the clinician's questions. In the typical cases, ultrasound has a major role in the prognosis, as it allows evaluation of the severity of the lesions. On the other hand, in atypical cases, ultrasound has a decisive role in planning the management, which will be immediate surgery when sonographic findings highly suspicious for testicular torsion or acute ischemia of the testis are found. Based on our experience, we believe that ultrasound is a highly reliable modality for guiding medical or surgical treatment of an acute scrotum.

Acute Disease↗
PubMed1987

Stabilization of phosphofructokinase during air-drying with sugars and sugar/transition metal mixtures.

Phosphofructokinase (PFK) purified from rabbit skeletal muscle is fully inactivated after air-drying and rehydration. The addition of trehalose, maltose, or sucrose to the enzyme solution prior to rapid drying results in a recovery of almost 70% of the original activity, whereas about 30% is recovered during slow drying. Similar stabilization is seen with up to 200 mM lactose, but at higher concentrations the sugar comes out of solution during drying, and there is a dramatic drop in the activity recovered. Glucose at concentrations up to 500 mM is ineffective at protecting air-dried PFK. Addition of ionic zinc to enzyme-sugar mixtures prior to drying greatly enhances the stabilization imparted by the above sugars, but zinc alone affords no protection. Several other organic solutes (proline, glycine, trimethylamine N-oxide, glycerol, and myo-inositol) that afford cryoprotection to PFK, an effect enhanced by the addition of zinc, do not stabilize the enzyme during air-drying, even if zinc is present. The addition of ionic copper, cobalt, or nickel to trehalose-PFK solution prior to rapid drying results in a large increase in the activity recovered, and the presence of cadmium or manganese leads to a minor increase. Magnesium and calcium are ineffective in this respect. During slow drying, the presence of cadmium or calcium leads to increased preservation, magnesium and manganese have no influence on stabilization, and copper and nickel inactive the enzyme.

Air↗
PubMed1987

Monoclonal antibodies against human astrocytomas and their reactivity pattern.

The establishment of hybridomas after fusion of X63-Ag8.653 mouse myeloma cells and splenocytes from BALB/c mice hyperimmunized against human astrocytomas is presented. The animals were primed with 5 X 10(6) chemically modified uncultured or cultured glioma cells. Six weeks after the last immunization step an intrasplenal booster injection was administrated and 3 days later the spleen cells were prepared for fusion experiments. According to the specificity analysis of the generated antibodies 7 hybridoma products (MUC 7-22, MUC 8-22, MUC 10-22, MUC 11-22, MUC 14-22, MUC 15-22 and MUC 2-63) react with gliomas, neuroblastomas and melanomas as well as with embryonic and fetal cells but do not recognize non-neurogenic tumors. The selected monoclonal antibodies (McAbs) of IgG1 and IgG2a isotypes are not extensively characterized but these antibodies have been demonstrated to be reactive with a panel of glioma cell lines with varying patterns of antigen distribution. Using the McAbs described above and a series of cryosections of glioma biopsies and paraffin sections of the same material as well as glioma cultures established from these, variable antigenic profiles among glioma cell populations could be demonstrated. From these results it is evident that there is not only a distinct degree of antigenic heterogeneity among and within brain tumors, but also that the pattern of antigenic expression can change continuously. Some of the glioma associated antigens recognized by the selected antibodies persist after fixation with methanol/acetone and Karnovsky's fixative and probably are oncoembryonic/oncofetal antigen(s). The data suggest that the use of McAbs recognizing tumor associated oncofetal antigens in immunohistochemistry facilitates objective typing of intracranial malignancies and precise analysis of fine needle brain/tumor biopsies in a sensitive and reproducible manner.

Animals↗
PubMed1987

Investigations of culture medium-free house dust mites. III. Antigens and allergens of body and fecal extract of Dermatophagoides farinae.

Crossed immunoelectrophoresis (CIE) and crossed radioimmunoelectrophoresis (CRIE) were used to characterize antigens (Ags) and allergens derived from Dermatophagoides farinae (DF) culture media-free mite body and mite fecal matter extracts. CIE of DF body and DF feces extracts revealed the presence of 35 and 20 Ags, respectively. CRIE experiments demonstrated IgE binding by 14 and seven DF body and DF feces Ags, respectively, when CIE gels were incubated with reference sera from clinically mite-sensitive patients. Binding of specific IgE to the various Ags in the two extracts varied significantly both in frequency and in strength from patient to patient and within the same patient's serum. Sera from some patients demonstrated IgE binding predilection for specific DF body Ags, whereas other sera exhibited greater binding preference for DF feces Ags. Homologous, heterologous, and intermediate gel CIE and CRIE clearly demonstrated that DF bodies and DF feces share some common Ags or epitopes, but the two different extracts also were quantitatively different. Some Ags and allergens originate from mite body material and are not present in mite feces. These results indicate that only extracts containing high concentrations of both body and fecal allergens should be used in clinical testing and therapy.

Allergens↗
PubMed1987

Constitutive expression of erythromycin resistance mediated by the ermAM determinant of plasmid pAM beta 1 results from deletion of 5' leader peptide sequences.

We have sequenced the erythromycin resistance determinant (erm) of the Streptococcus faecalis plasmid pAM beta 1 to investigate its relationship to other known resistance determinants. We show that this determinant is strongly (99%) homologous at the DNA level to that of plasmid pAM77 (Streptococcus sanguis) and of transposon Tn917 (S. faecalis). Moreover, nucleotide sequence comparison with the determinants of pAM77 and Tn917 shows that most of the probable regulatory region is absent, providing an explanation for the constitutive expression of the pAM beta 1 erm determinant.

Base Sequence↗
PubMed1987

Digitonin cytochemistry reveals cholesterol-rich vesicles in uterine epithelial cells.

Freeze-fracture cytochemistry with digitonin has been used to examine the cholesterol content of the large apical vesicles of uterine epithelial cells. The vesicles are found to have cholesterol-rich membranes which supports the view that they are involved in cell secretion. We comment on the possible role of the vesicles in implantation.

Animals↗
PubMed1987

Phenotypic composition and in vitro functional capacities of unmodified fresh cells infiltrating acutely rejected human kidney allografts.

Cell surface markers of isolated graft-infiltrating cells (GIC) were studied, and functional in vitro assays performed in 8 cases of acute irreversible rejection of human renal allografts. The GIC were mostly activated T cells (OKT11+, OKT3+, Ia+), with predominance of the cytotoxic/suppressor T cell phenotype (OKT8+). A small proportion of B cells and monocytes/macrophages were also present among these GIC. The GIC were able to proliferate with lectin of allogeneic stimulation and were strongly cytotoxic toward specific donor target cells. Within the T cell subset, OKT8+ cells displayed most of the specific cytotoxicity. Despite allograft morphology typical of cellular rejection, anti-HLA complement-dependent antibodies and antibody-dependent cell cytotoxicity were found in the eluted material from rejecting kidneys. The results of our phenotypic and functional testing of unmodified GIC (no enzyme treatment, no additional culture with or without interleukin 2), show that T cells, especially OKT8+ cells, are of paramount importance in the mechanism of this type of acute irreversible rejection of human renal allografts (i.e., to the point of allograft rupture), but other potential effector mechanisms are also present in situ.

Antigens, Surface↗
PubMed1987

Comparative pharmacokinetics of gentamicin, neomycin and oxytetracycline in newborn calves.

The pharmacokinetics of three antibiotics--gentamicin, neomycin and oxytetracycline were determined in newborn calves. The kinetic determinations, using two-compartment open models, were made at increasing ages from 1 day to 42 days and compared with those made from older calves (250+ days). Although all three antibiotics are eliminated unchanged primarily by glomerular filtration, there were marked differences in the development of elimination processes for individual drugs. The pharmacokinetics of neomycin were not influenced by age. Although the elimination half-life of gentamicin appeared to decrease with age, the changes were not significant and were due to an increased elimination rate in only one calf. There was no change with age in the remaining three calves. Oxytetracycline elimination was significantly reduced in newborn calves. This was exemplified by a decrease in the half-life of elimination t1/2 (beta) from 672.5 +/- 99.4 in the newborn to 385.6 +/- 76.8 at 6 weeks of age, and 377.3 +/- 40.8 min in the 250-day-old calf. These changes were consistent in all four calves. The rate of elimination remained low for the first 4 weeks of life. The volume of distribution Vd, area was not changed after the first week of life. Based on pharmacokinetic changes, an adjustment of dosage is indicated for oxytetracycline in the newborn calf as compared to the older calf or adult.

Age Factors↗
PubMed1987

[Anti-cytomegalovirus T-cell immunity and HLA restriction in the transplanted kidney patient].

Cytomegalovirus (CMV)-specific immune T-cells, present in the circulation of previously infected kidney transplant recipients (anti-CMV serum antibody titer greater than 1/40) can be reactivated to give rise to specific helper and cytotoxic effector cells by co-culturation with fresh autologous blasts coated with CMV antigen in vitro. The reactivated cells are able: 1) to proliferate when stimulated with CMV antigen, 2) to kill the autologous target coated with CMV antigen and not autologous blasts alone when assayed in 51Cr release test. These specific effector cells lie in the E+ T cell subset by removing NK cells with sheep-erythrocytes rosetting. When the reactivated cells are tested against allogeneic CMV coated blasts the level of cytotoxicity is in general related to the extent of HLA-A and B antigen sharing between effector and target cells. The results provide strong evidence that: 1) only previously infected individuals can generate immune T cells against CMV in vitro, 2) there is a correlation between the index of proliferation and cytolysis, 3) there is an HLA restriction of immune T cell cytotoxicity of CMV, 4) monoclonal antibodies directed at several antigenic sites of CMV are able to block cytolysis.

Adolescent↗
PubMed1987

[Desmoid fibroma of the abdominal wall. Apropos of a case].

A case of desmoid fibroma of anterior abdominal wall, an exceptional benign tumor, is reported. Based on results of CT scan imaging of this lesion, differential diagnosis of other expansive processes of abdominal wall are discussed. This benign tumor is a potentially serious lesion due to its infiltrating character and the high incidence of recurrence. The need for total surgical excision is emphasized.

Abdominal Muscles↗
PubMed1987

[Ultrasonic diagnosis of non-palpable germinal tumors of the testis. Apropos of 2 cases].

The germ cell tumors are the most common type of testicular malignant tumors (90%). About 30% are revealed by metastasis usually into the retroperitoneum, with clinically normal testis. Ultrasound reveals a bright echogenic focus into the testis which is typical, considering the clinical presentation, for a regressed germ-cell tumor and guides the side of the orchidectomy which allows to suppress a still active tumoral tissue which will not be eradicated by chemotherapy. Two typical cases with sonographic guidance are reported herein and confronted with the cases previously described in the literature.

Adult↗
PubMed1987

Receptor-assay for endogenous inhibitors of Na-K ATPase.

It is now accepted that there is an endogenous digitalis-like substance (EDLS), previously called natriuretic factor, present in different mammalian species which participates to the regulation of the sodium balance and at least in some situations, to the genesis of hypertension. The physiological and pathophysiological role of this substance is well recognized. However, its chemical nature remains elusive. Our purpose was to define a receptor assay for this EDLS in order to be able to measure its concentration in urine and blood. To do so, we first prepared a pool of lyophylised urine from salt loaded men. The active material was isolated by Sephadex G25 chromatography. Using the same active fraction, we investigated its biological effects. Series of experiments have demonstrated the various properties of the EDLS: inducing natriuresis when injected into a rat, diminishing short circuit current in toad's bladder and colonic mucosa of rat in in vitro preparations, inhibiting Na-K ATPase activity in isolated toad's bladder cells, binding to ouabain receptors and cross-reacting with different antibodies directed against digoxin. Among these properties, the binding to ouabain receptors offers the unique opportunity to progress in our knowledges of the substance, making possible the calculation of its constant of affinity and the estimation of the molality of the active material contained in a gram of crude extract. Knowing the constant of affinity of the EDLS for its receptor would provide the best identification of the substance as long as we do not know its exact chemical nature.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗