Ontogeny of the Fc gamma receptor in rat small intestine

The time course of Fc gamma receptor expression on isolated enterocytes of the small intestine of rat fetuses and sucklings has been studied. This was achieved principally using indicator sheep red blood cells (SRBC) sensitized with rabbit IgG in an erythrocyte-antibody rosette assay which detects receptors located mainly on the lateral and basal plasma membrane, and in a more limited way using binding of rabbit IgG to metabolically inhibited gut as detected by immunofluorescence and which detects receptors located on the apical brush border. From the time they were first detectable in the rosette assay (20-day-old fetuses) to the time they disappeared (22-day-old sucklings) such receptors were found always to be acid pH dependent and restricted to enterocytes from the proximal region. Acid pH, Fc-dependent binding of rabbit IgG to metabolically inhibited gut was first detectable at 21 days gestation and there were indications that receptors differentiate on enterocytes in a proximal to distal direction. This was also indicated by electron microscope studies using rabbit PAP injected into the duodenum of 21-day-old fetuses. Such studies also provided evidence for the receptor-mediated translocation of IgG across the duodenum of the fetal rat in a manner similar to that described for older sucklings.

Effect of drugs, hormones and electrical field stimulation on isolated muscle strips from human choledochoduodenal junction

The behaviour of in vitro strips from the human choledochoduodenal junction would appear to be related to the anatomical location of origin of the strip. Strips from the papillary region showed low tone and obvious spontaneous rhythmic contractions (0 X 5-6/min). Strips from the region of the inferior choledochal sphincter showed, in ten out of fifteen specimens, spontaneous myogenic tone and gave a relaxation or a biphasic response (relaxation followed by contraction) to electrical field stimulation (0 X 3 ms pulses at 10 Hz for 5 s). All strips from human choledochoduodenal junction are remarkably insensitive to a variety of gastrointestinal hormones and to opioid agents.

The treated histories of patients with Ta grade 1 transitional-cell carcinoma of the bladder

One hundred sixty patients with grade 1 transitional-cell carcinoma of the bladder were evaluated and treated at the Massachusetts General Hospital, Boston. The mean follow-up period was 57 months. There were 92 new patients and 68 patients who had a history of transitional-cell carcinoma. Fifty-three patients (33%) never had another transitional-cell carcinoma. Sixty-eight (43%) of the remaining 107 patients had recurrent Ta grade 1 transitional-cell carcinoma. In 32 patients (20%) disease progressed in grade, in seven patients (4%) invasive transitional-cell carcinoma developed, five patients underwent cystectomy, and one patient died of transitional-cell carcinoma. High-risk factors included positive results of cytologic studies after therapy and three or more recurrences. Multiple therapies were used, but it is impossible to determine if anything other than transurethral resection altered the course in these patients. The data suggest that patients with low-risk factors and Ta grade 1 tumors might be followed up with a quarterly cytologic examination and cystoscopy once or twice a year, unless a change in symptoms occurs.

Influence of tamoxifen and estradiol on the growth of human breast cancer cells in vitro

Cells obtained from freshly resected human breast cancer were grown in vitro utilizing the soft agar technique. The effects of adding an antiestrogen (tamoxifen, TAM) and 17 beta-estradiol alone or simultaneously on cell growth were assessed. The addition of TAM (10(-6) M) to the medium resulted in a significant decrease in cell growth in 26 of 36 (72%) estrogen receptor (ER)-positive tumors and in one of 5 ER-negative tumors (20%). The degree of inhibition caused by TAM was significantly higher in the ER-positive tumors that also contain the progesterone receptor (PgR) as compared to those that lacked that receptor (i.e., PgR negative) (46.2 +/- 2% versus 36.2 +/- 1.2% inhibition, P less than 0.01). The simultaneous addition of 17 beta-estradiol (10(-8) M) neutralized the inhibitory effect of TAM (10(-6) M) in the majority of tumors. With the presence of serum in the medium, the addition of 17 beta-estradiol alone resulted in an enhancement of cell growth in 6 of 17 tumors. However, because of the confounding effects of serum in the medium, we studied the individual effect of 17 beta-estradiol (10(-8) M) when added alone under serum-free conditions. Of 20 tumors studied, 17 beta-estradiol significantly enhanced cell growth in 12. There was a 67.8 +/- 12.6% increase in the number of colonies formed in these 12 responding tumors. One of these 12 responding tumors was ER negative as well as PgR negative, while the rest were all ER positive. These in vitro studies demonstrate that this approach can provide valuable information on endocrine mechanisms controlling the growth of human breast cancer.

Changes in specific B cells and the dissemination of the primed state in vivo following antigenic stimulation by different mucosal routes

Immunologic dogma holds that the adaptive and long-term potential of the antibody response is fashioned by antigen-dependent, selective clonal proliferation of specific B cells and the retention of some which may undergo a second round of antigen-stimulated clonal expansion with antibody production. Apparently, the short-term, immediate consequences of an antibody response depend on the mix of isotypes displayed in vivo upon exposure to antigen. This latter seems to be clearly regulated by T cells, but it is also likely that the isotype potential of a B cell population and its future possible display of isotypes is linked to the initial, antigen-dependent proliferative phase in the development of an antibody response. In vitro analysis at limiting dilutions of specific B cells primed in vivo has led to the operational definition of IgA-committed cells. These B cells increase in frequency following chronic or acute antigenic stimulation of gut mucosa and have the potential to proliferate again in the presence of antigen and TH(Ag) cells to produce exclusively IgA. A general relationship exists between mucosal or parenteral priming of B cells and their potentials to express IgA and/or IgE--both isotypes appear to be likely products of secondary B cells and frequently both can be expressed by the same clone activated by a second-round of T-dependent antigenic stimulation. Cross priming--exposure of GALT or BALT leading to secondary B cells in the opposite mucosal lymphoid tissue--suggests an inherent antagonism between development of allergic (IgE) and putative allergy blocking (IgA) potentials.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth enhancement of N-nitrosomethylurea-induced rat mammary tumor cells in soft agar by estrogen or prolactin

Cells obtained from N-nitrosomethylurea-induced rat mammary tumors were grown in vitro using the soft-agar clonogenic assay technique. Their growth was studied in regular media containing serum as well as in media lacking serum, but to which insulin was added. Deletion of serum from the media resulted in a mean decrease of 49% in the number of colonies formed in vitro in 13 of 18 tumors and was without effect in the remaining 5 tumors. The addition of either 17 beta-estradiol (10(-8) M) or ovine prolactin (OPRL, 100 ng/ml) to the defined media resulted in an increase in the number of colonies formed in 12 of 18 tumors. The mean numbers of colonies per Petri dish in 17 beta-estradiol- and OPRL-treated Petri dishes were 95 +/- 5.4 (S.E.) and 92 +/- 6.2% of the values seen in serum-containing media. Simultaneous addition of both hormones to the defined media resulted in a significant increase in the number of colonies formed which was greater than that seen when either hormone was added separately. Of four tumors where neither hormone influenced colony formation, the addition of both 17 beta-estradiol and OPRL resulted in an increase in the number of colonies formed in three tumors. We conclude that the N-nitrosomethylurea-induced mammary tumors can be grown in soft agar using defined media and that their growth can be enhanced by either 17 beta-estradiol or OPRL. These hormones have a synergistic effect on the growth of some of these tumors in vitro. These data are consistent with the known in vivo effects of these hormones on the N-nitrosomethylurea-induced rat mammary tumors.

Cryptosporidiosis of the human small intestine: a light and electron microscopic study

Intestinal infection by the coccidian parasite Cryptosporidium is a well-recognized condition in immunocompromised hosts and in some normal persons. The authors studied a patient with acquired immunodeficiency syndrome and cryptosporidiosis of the small intestine. The parasite inhabits the microvillous brush border of the intestinal epithelium and must be carefully sought on light microscopic examination of intestinal biopsy specimens. Characteristic life cycle stages are observed on electron microscopy. The absence of significant light microscopic alterations of the villous architecture in this patient's biopsy specimen and in other cases suggests that other factors, such as toxin elaboration by cryptosporidia or other organisms, may be involved in the pathogenesis of diarrhea. Abnormal aggregation of lysosomes at the apices of intestinal epithelial cells may reflect ineffective host phagocytic mechanisms.

Laboratory stress: what causes it?

One hundred-fifty questionnaires were distributed to gather specific information about the causes of stress in the hospital-employed medical technologist (MT). Sixty-four percent were returned. The results were analyzed using Friedman's two-way analysis of variance by ranks. Although the causes of stress to the medical laboratorian are many and they are affected by variables within the worker, certain items are more significant causes of stress than others. Physicians, stats, the need for accuracy, lack of communication, errors, and overwork are major causes of stress. These are the stressors that must be controlled or modified to reduce stress to the MT employed in a hospital laboratory.

Minocycline diffusion into benign prostatic hyperplasia

Minocycline, a broad-spectrum, highly lipid soluble tetracycline that has generated interest in the treatment of chronic prostatitis, was evaluated for its possible ability to be concentrated in benign prostatic hyperplasia. Drug levels in the prostate, plasma, fat, muscle and urine were measured in patients undergoing open prostatectomy after preoperative intravenous minocycline. The concentrations of the drug in the prostate and serum were close (4.16 versus 3.01 microgram. per gm.), while drug levels in striated muscle and fat were consistently lower (2.92 and 0.77 microgram. per gm). Higher preoperative doses of drug yielded higher tissue levels. Drug delivery closer temporally to the operation yielded higher serum and prostatic levels as opposed to striated muscle and fat, suggesting a rapid diffusion of the drug into benign prostatic hyperplasia.

Pyogenic osteomyelitis of the spine

The records of 30 patients who had suffered from vertebral osteomyelitis were reviewed. They conformed to a constant pattern, though varying in tems of: (i) the severity of the disease due to host-organism interrelationship; and (ii) age distribution. Causative organisms could not always be identifed, though all lesions settled with conservative measures of rest and antibiotics. A high proportion of the patients who were followed up for more than one year were back at work. The anatomical distribution of the lesions can be explained by our knowledge of the vascular supply to the vertebral bodies.

Effect of gas physical properties and flow on lower pulmonary resistance

We measured lower pulmonary resistance (Rlp) in eight dogs and three men breathing gas mixtures having different densities (p) and similar viscosities (mu). Rlp increased with gas density and with flow rate (V). In the dogs, these effects were not observed in lung segments subtended from 4-mm-ID bronchi; in more central airways, resistance varied approximately as (mup V)0.5. These results are compatible with Poiseuille flow in peripheral airways, and, in central airways, with flow resistance described by the equation of boundary layer growth. Rather than two discrete flow regimes, it is likely that flow patterns undergo a continual metamorphosis as Reynolds' numbers (Re) decrease between trachea and alveoli. Accordingly, the airways pressure-flow relationship is not described by any single fluid dynamics equation, but may be explained by the general equation, P = Kmu2-apa-1Va, where a reflects the proportion of inertial to viscous pressure losses and varies between 1 and 2 according to Re. Rohrer's equation described the observed pressure-flow relationships and predicted the change in Rlp with gas physical properties, suggesting a physical basis underlying this adequate mathematical description.