Ions and water in the epithelial cells of rabbit descending colon

1. Isolated sheets of rabbit descending colon epithelial cells stripped from their underlying muscle coats were incubated in chambers at 37 degrees C with oxygenated media, and their non-inulin space water, sodium, potassium and chloride contents were subsequently determined. 2. With sodium Ringer bathing both surfaces, amiloride, 10(-4) M, decreased non-inulin space sodium content by 76 mmol/kg dry wt. Ouabain, 10(-3) M, caused loss of non-inulin space potassium which was not completely compensated for by uptake of sodium over 30 min incubation. Chloride and water, therefore, decreased. Amiloride, 10(-4) M, inhibited but did not prevent this uptake of sodium after ouabain. 3. Tissues exposed to sodium-free choline Ringer rapidly exchanged non-inulin space sodium for choline and, more slowly, lost potassium, chloride and water. The equilibration of sodium in the non-inulin space when sodium Ringer was restored to the mucosal medium alone was largely amiloride-insensitive. For restoration of non-inulin space potassium to normal levels, sodium was required in the serosal but not the mucosal medium. 4. Neither the absence of glucose nor the absence of chloride from the mucosal medium affected the non-inulin space sodium content when sodium was restored to the mucosal medium bathing sodium-depleted tissues. 5. It is argued that, whereas non-inulin space potassium and water contents are synonymous with their cellular values, only about one third of non-inulin space sodium is cellular when sodium Ringer bathes both surfaces, and the concentration of the sodium within the cellular transport pool approximated 20 mmol/kg H2O, consistent with estimates obtained from other techniques.

A combined in vivo/in vitro study of the presynaptic release of adenosine derivatives in the hippocampus

To investigate the release of adenine compounds from defined neuronal pathways, we employed a hippocampal slice preparation in which a selective-loading of the releasable pools was achieved in vivo with the aid of axonal transport. By injecting radioactive adenosine stereotaxically into the entorhinal cortex, the major afferent system to the dentate gyrus (the perforant path) was loaded within 20-36 h, at which time the rats were killed and hippocampal slices were prepared. The efflux of radioactive material, as recovered from the perfusate and measured in a scintillation counter, was found to be significantly increased in response to electrophysiologically controlled stimulation of the perforant path but not to stimulation of an alternative fiber tract, the fimbria. These findings provide supportive and more direct evidence for an activation-coupled release of adenosine derivatives from presynaptic sites in the central nervous system.

Structural responses to voltage-clamping in the toad urinary bladder. II. Granular cells and the natriferic action of vasopressin

The natriferic action of vasopressin has been investigated with morphological studies of voltage-clamped toad urinary bladders. Granular cell swelling can be induced in the presence of isoosmotic solutions when the orientation of the transmural potential is reversed by voltage clamping (V.A. Bobrycki, J. W. Mills, A.D.C. Macknight & D. R. DiBona, J. Membrane Biol., 60:21, 1981) and results from an increased rate of sodium entry across the mucosal membrane; under these conditions the active transport mechanism at the basal-lateral membrane becomes rate-limiting. Vasopressin exacerbated the voltage-reversal-induced swelling of granular cells while other cell types were unaffected. Granular cell swelling appeared to be dependent upon sodium entry from the mucosal medium since it was completely prevented by amiloride. There was no evidence for an effect of vasopressin on tight junction permeability; voltage-reversal induced the same amount of junction blistering whether or not vasopressin was present. It is concluded that the predominant effect of vasopressin on transepithelial sodium transport is to increase the sodium conductance of the mucosal plasma membrane. As is the case with the hydroosmotic effect of the hormone, the natriferic action of vasopressin seems to be exerted primarily, if not entirely, on the granular cells.

Predictors of the outcome of transsphenoidal surgery for prolactin-secreting pituitary adenomas

Sixty-seven women who underwent transsphenoidal resection of PRL-secreting pituitary adenomas between 1976 and 1979 were separated into categories according to the manner of their clinical presentation. Forty-one had oral contraceptive-related onset of amenorrhea-galactorrhea, 5 had pregnancy-related onset of amenorrhea-galactorrhea, 5 had primary amenorrhea, and 16 had the spontaneous onset of amenorrhea-galactorrhea unrelated to estrogen use. Surgical success, defined as the resumption of regular menses and normalization of serum PRL concentration, was achieved in 54% of those with estrogen-related onset of amenorrhea-galactorrhea compared with 19% in the other group. The analysis of multiple preoperative features, including clinical classification, age, preoperative PRL concentration, and duration of amenorrhea-galactorrhea by logistic regression, demonstrated that the clinical classification was the most important factor in predicting the outcome of transsphenoidal surgery. It should be a prime consideration in the selection of therapy for PRL-secreting adenomas.

Relationship of body weight to menarcheal and menopausal age: implications for breast cancer risk

Early menarche and late menopause are risk factors for the development of breast cancer. An adequate hormonal mechanism for those observations has not been described. Because obesity has also been associated with increased breast cancer risk, we examined the relationship among height, weight, adiposity, and menstrual cycle characteristics in women who prospectively recorded menstrual cycle intervals and reproductive events as part of the Menstrual and Reproductive History Research Program. Within this study cohort, adult height, weight, and a derived index of adiposity were related to both earlier age at menarche and later age at menopause. The association of early age at menarche with adiposity persisted from age 18 yr through middle age and into the menopausal years. There was no relationship between body mass and age at first pregnancy, another breast cancer risk factor. Women who were heavier at 18 yr of age and thereafter gained 5 lb or more had significantly greater mean menstrual cycle length and variability during the 7-yr period after menarche than the other members of the cohort. There was no obvious relationship between weight indices and menstrual cycle pattern during mature reproductive life or during the 7 yr before menopause. Our data suggest that menarcheal and menopausal age may have a common relationship to nutritional status and to constitutional features that predate the onset of menarche and persist into later life.

1-phenylalanine mustard (L-PAM) in the management of premenopausal patients with primary breast cancer: lack of association of disease-free survival with depression of ovarian function. National Surgical Adjuvant Project for Breast and Bowel Cancers

Breast cancer patients participating in a prospective randomized clinical trial who were less than or equal to 49 years of age, had positive axillary nodes, and who received prolonged 1-phenylalanine mustard (L-PAM) as an adjuvant to mastectomy continue (after 4 years) to demonstrate a significantly greater disease-free survival (p = .007) than do patients who received placebo. Benefit was achieved in patients who were less than or equal to 39 years as well as those who were 40-49 years of age. Those in the younger age group showed a greater improvement in disease-free survival at 4 years relative to their controls (32% vs. 69%; p = .01) than did those in the older age group (48% vs. 61%; p = .09). When patients were examined relative to their nodal status, a highly favorable effect was found to have been achieved with L-PAM in those with 1-3 positive nodes (54% vs. 86%; p = .006). Results indicate that both age groups were benefited. When considered over time, they demonstrate that a relatively greater effect was achieved in the younger women. While L-PAM failed to significantly alter the disease-free survival of those with greater than or equal to 4 positive nodes a slightly better effect was achieved in the group less than or equal to 39 years. Since adjuvant chemotherapy has been found to be more effective in premenopausal than postmenopausal women, it has been presumed that decreased ovarian function, as a result of the chemotherapy, is responsible for the findings. To support or repudiate that concept, information regarding serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2), as well as menstrual function, has been obtained from women receiving L-PAM or L-PAM plus 5-FU therapy. In contrast to findings relative to disease-free survival, ovarian function and menses were most affected in patients 40-49 years of age. Amenorrhea occurred in 73% of patients in that age group and in only 22% of those less than or equal to 39 years (p less than .001). Similarly, a significant increase in LH and FSH and a decrease in E2, all indicative of ovarian suppression, was observed only in the older group of patients. Thus, it is concluded that while ovarian suppression may account for some of the adjuvant chemotherapeutic effect in premenopausal women, the dichotomy of findings in younger and older premenopausal women relative to therapeutic response and ovarian function indicates that other factors could be responsible.

Effects of inhaled beclomethasone dipropionate and alternate-day prednisone on pituitary-adrenal function in children with chronic asthma

Two corticosteroid regimens, alternate-day prednisone and inhaled beclomethasone dipropionate, have been more acceptable than daily oral corticosteroids for treatment of chronic asthma. To compare the effect of these regimens on hypothalamic-pituitary-adrenal function, 20 children with asthma were evaluated while receiving 20 to 40 mg of prednisone on alternate mornings or 400 to 800 microgram per day of inhaled beclomethasone dipropionate in divided daily doses; seven children requiring only non-corticosteroid medication served as controls. Early-morning serum cortisol concentration, urinary free-cortisol excretion and the 11-desoxycortisol response to metyrapone were decreased to a similar degree among children receiving both corticosteroid regimens in comparison with the control patients and were lowest when alternate-day prednisone and inhaled beclomethasone dipropionate were given together. Thus, inhaled beclomethasone dipropionate appears similar to alternate-day prednisone in its effect on hypothalamic-pituitary-adrenal function when used alone; the effect is additive when the two are used together.

Perception and interpretation of explicit negations by learning-disabled children and adolescents

The present study evaluated and compared the preception and interpretation of 21 explicit negative sentences by 15 learning disabled third graders and 15 controls, 20 learning disabled adolescents and 20 controls, and 16 randomly selected adults. The proportions of correct interpretations of the experimental sentences did not differ significantly among subject groups. In a similar vein the proportions of correct responses to individual test items did not differ significantly. The findings suggest that the learning-disabled third graders and adolescents adequately perceived the stressed negated elements and interpreted the meanings of the explicit negative sentences appropriately. These findings conflict with previous observations that dyslexic children experienced problems in processing prosodic suprasegmental features (Vogel, 1974).

Echocardiographic evaluation of pericardial effusion in myxedema. Incidence and biochemical and clinical correlations

Pericardial effusion is a recognized consequences of myxedema. Its incidence is unknown, primarily because of past difficulties in establishing the diagnosis. We studied 33 hypothyroid patients by echocardiography. Ten of the 33 patients (30%) had positive echoes for pericardial effusion. Seven of these ten patients had enlarged hearts on chest X-ray. Five patients had cardiac enlargement but no echo evidence of pericardial effusion. Serum concentrations of thyroxine, 1.8+/-0.3 vs 1.5+/-0.1 mcg/dl and of thyroid stimulating hormone, 34+/-4 vs 38+/-5 muU/ml did not differ in the groups with and without pericardial effusion, respectively. However, the pericardial effusion group had significantly slower heart rates on ECG than those without pericardial effusion: 53+/-8 vs 68+/-2 beats/min, P less than 0.05. Low voltage was present in five of the ten patients with pericardial effusion and five of the 23 nonpericardial effusion patients. None of the patients with pericardial effusion developed tamponade. Seven patients with pericardial effusion were restudied after periods of thyroxine replacement therapy ranging from six months to two years. All were euthyroid and had negative echoes on follow-up, but two still showed cardiomegaly on chest X-ray (both had associated coronary artery disease). We conclude that pericardial effusion occurs frequently in patients with myxedema. Tamponade is uncommon and the effusions disappear with thyroid replacement therapy. Cardiomegaly on chest X-ray and low voltage on ECG are not reliable indicators of pericardial effusion.

Scanned-laser microscope for photolurminescence studies

A scanned-laser microscope has been developed to generate photoluminescence maps, or images, of semiconductor samples. This instrument is shown to be extremely useful for evaluating semiconductor wafers, especially those intended for light-emitting diodes. The design and construction of this new microscope are discussed, and performance tests of a prototype are presented. The photoluminescence microscope achieves a spatial resolution near 10(-3) cm with a spectral definition of 100 A and examines an area 0.6 cm on a side in a few seconds. Examples of the application of the photoluminescence microscope to testing of GaAsP wafers are presented and compared with the results of other kinds of tests to determine the suitability of these wafers for light-emitting diodes.

Proinsulin-like component of circulating insulin in the basal state and in patients and hamsters with islet cell tumors

The proinsulin-like component comprised approximately 20% of total circulating basal immunoreactive insulin in 15 patients without islet cell tumors. 15 min after oral glucose, the concentration of the proinsulin-like component was unchanged and its percentage of the total immunoreactive insulin decreased with the acute release of the insulin component. By 2 hr after oral glucose, the concentration of the proinsulin-like component increased and the insulin component concentration decreased so that the percentage of the proinsulin-like component was essentially the same as in the basal state. In five patients with islet cell tumors and fasting hypoglycemia, basal proinsulin-like component ranged from 26 to 79% of the total immunoreactive insulin. While basal proinsulin-like component was higher in the islet cell tumor patients, the fluctuations after stimulation were qualitatively similar to the nontumor patients. Acute stimulation with glucose, tolbutamide, leucine, and streptozotocin mainly released the insulin component resulting in a fall in the per cent proinsulin-like component with a subsequent increase in percentage of this component as the total insulin concentration returns towards basal levels. Three islet-cell tumor patients with less than 46% proinsulin-like component had favorable therapeutic responses to diazoxide whereas one patient with over 80% proinsulin-like component was completely refractory. Syrian hamsters bearing islet cell tumors provided an excellent model for islet cell tumors in man. These animals have a high proportion of a proinsulin-like component in plasma; stimulation of tumor slices in vitro with tolbutamide and glucagon releases mainly the insulin component similar to the observations in man. These studies suggest that the mechanisms regulating the release of the proinsulin-like and of the insulin components are different.

Scanned laser infrared microscope

In examination of ir-transmitting materials, internal irregularities and inclusions of foreign material can be detected by their effect upon the ir transmittance of the material. A scanning laser ir microscope has been constructed which produces, on an oscilloscope display, a shadowgraph picture of the ir transmittance of the material under examination. The 3.39-micro emission of a He-Ne laser serves conveniently as the ir source since many materials of interest transmit at this wavelength. The scan consists of a raster of 400 lines, and is completed in 1 sec. The detector is a room temperature operated indium arsenide photovoltaic cell, with a time constant of 2 microsec. A sample area of 1.2 cm x 1.2 cm is scanned with a focused spot having a nominal diameter of approximately 0.003 cm. The optical and electromechanical features of the microscope are described, and its application to examination of semiconductor materials is illustrated by several typical examples.

VlI. An extraordinary case of a costive person, in a letter from Mr B. Sherman to Dr Beeston of Ipswich; with a note on the same by Mr William Cowper, F. R. S

Sir, This person, whose Name was Thomas Phillips of Easthorp , near Keldon in Essex , was as well in every respect as a Child could possibly be till he was a year and a quater old; at which time a very strange and almost continual rumbling in his Intestines seiz’d him, the consequence was a violent Looseness, for which all the Physicians near the place could find no Remedy: But at last, when they despaired of the Childs Life, the Loose-nessr terminated in suchan unusual Obstrction, that he did not go to Stole for a fortnight or three weeks together, and from three weeks it proceeded gradually to the intervals of 17 or 18 weeks, and so continued till he came to be about the age of fifteen, when his Body resumed its natural temper, which lasted 4 or 5 years, but then the Obstrction returned, and continued, or rather increas’d till he dyed; for it was customary with: him in the last years of his Life not to evacuate any manner of Excrement under the interval of nineteen or twenty weeks, and sometimes (twice at least) he had no discharge for one or two and twenty weeks together.