Mycoplasma pneumoniae is a common etiologic agent of lower respiratory tract infections in humans. However,ithasbeenreportedpreviouslythattheorganismhasoccasionallybeenisolatedfromsitesotherthan the oropharynx and respiratory tract. We report the isolation of 24 strains ofM. pneumoniaefrom urogenital specimens obtained from 22 female patients. Most isolates were of cervical origin from patients attending several local gynecological clinics over a 2-year period. Strains were also isolated from the urethra of one of three healthy male sexual partners of female patients positive for the organism. Single serum specimens obtainedfromthreefemalepatientsandthreedifferentmalesexualpartnersshowedantibodylevelssuggestive of either recent respiratory infection or genital tract colonization with M. pneumoniae. Although there is no apparent definitive explanation for the localized outbreak of the organism at these unusual sites, the possible transfer through sexual and/or orogenital contact remains the most likely mode of transmission. The occur- rence of an organism with obvious pathogenicity for human epithelial tissue in the urogenital tract suggests such transfer could play a role in genital tract infection. Mycoplasma pneumoniaeis one of the commonest etiologic agentsoflowerrespiratorytractinfectionsinhumans,account- ing for somewhere between 15 and 20% of all cases of pneu- monia (3, 7). The organism can clearly be associated with a wide range of mild to serious extrapulmonary complications following respiratory disease in adults, children, and infants. However, the most frequent clinical manifestations observed with the organism involve tracheobronchitis and pharyngitis, with almost 20% of infections being asymptomatic (3). In an earlier study in Canada (6), we isolated M. pneumoniae from

Synthetic TRH, crude hypothalamic extract and partially purified prolactin releasing factor stimulated prolactin and growth hormone release from isolated secretory granules. Somatostatin and partially purified prolactin release-inhibiting factor inhibited release of both hormones. Calcium promoted hormone release from granules; its releasing action was potentiated by TRH and ionophore A23187 but reduced by somatostatin.

Secretory granules containing prolactin (PRL) and growth hormone (GH) as essentially the only proteins were isolated by centrifugation. PRL and GH varied reciprocally in the granule preparations with the seasons. During winter PRL content was lowest (20%) and GH highest (80%); during summer the converse obtained: PRL, 70% and GH, 30%. Both hormones were in almost equal proportion during the spring. The amount of either hormone released from granules and pituitary slices was directly related to its relative content in the gland. The pattern of PRL release from secretory granules and pituitary tissue in, vitro was similar to that reported for blood levels in ruminants: low during winter and high during summer. It is concluded that seasonal factors affect primarily the synthesis and/or storage of PRL and GH, and there exists a direct relationship between intracellular stores and release.

Release of hormones from bovine anterior pituitary tissue in vitro was inveresly related to the osmolarity of the incubation medium. Addition of each of several ionic or non-ionic solutes to Krebs-Ringer-bicarbonate (KRB) or to beef serum inhibited hormone release. If the value of 286 mOsm/liter of KRB is considered as 100%, the osmolarity of the medium was altered from -15% to +10% of control. Over this range, an increase in osmolarity of 10% resulted in the following percentage inhibition: ACTH, 47; PRL, 43; TSH, 36; LH, 23; GH, 18; maximal percentage inhibition over this range was as follows: ACTH, 80; PRL, 60; TSH, 60; LH, 45; GH, 40. The inverse relationship between extracellular oxmolarity and secretion of ACTH and PRL would appear to be appropriate in view of the salt and water retaining actions of these hormones. The sensitivity of the response to osmotic changes suggests a possible role of body osmolarity in the regulation of adenohypophysial secretion.

Chromatographic fractions from acetic acid extracts of bovine posterior pituitarystalk-median eminence were tested for effects on the release of prolactin (PRL), GH, TSH, and LH from bovine anterior pituitary in vitro. The hormones were estimated by radioimmunoassay. One fraction distinct from pyro-Glu-His-Pro-NH2, enhanced release of PRL and had no effect on the release of the other hormones. Another relatively crude fraction inhibited release of three hormones in the following order of decreasing sensitivity: PRL < GH < TSH, whereas a more highly purified fraction, at the doses tested, inhibited PRL only. (Endocrinology94: 563, 1974)

PROLACTIN (PRL) secretion from the mammalian anterior pituitary gland is apparently chiefly under hypothalamic tonic inhibition in contrast to the primarily stimulatory influence of the brain on the other trophic hormones1. Extracts of mammalian hypothalamus inhibit the release of PRL in vitro and in vivo1. We report here that PRL-inhibiting-factor (PIF) activity in certain fractions derived from acetic acid extracts of bovine hypothalamus was due to nickel ion (Ni2+) in the extracts. Commercial nickel salts and purified PIF from bovine brain specifically inhibit release of PRL in vivo in the rat and in vitro from bovine pituitary, (a) in basal conditions, (b) in the presence of copper ion which markedly enhances release of all trophic hormones, and (c) following brief exposure of the pituitary tissue to cold, another effective, non-specific stimulant of hormone release.

Bovine anterior pituitary slices were incubated in Krebs—Ringer—Bicarbonate for 2 hr and TSH, LH, FSH, ACTH, GH and prolactin (PRL) released into the medium were estimated by radioimmunoassay. During continuous incubation at 0 C, release of hormones was increased 10 to 60 times the release at 37 C, except for PRL release which was unaltered. A 5–min exposure to cold resulted, during subsequent incubation at 37 C, in a similar augmentation of release of all hormones including PRL. The enhanced release upon exposure to cold resulted in depletion of total cellular hormone stores by 8, 16, 21, 43, 45 and 61 percent for PRL, FSH, TSH, LH, GH and ACTH, respectively. A purified “prolactin—inhibiting factor” reduced the effect of the 5–min cold pulse on the release of PRL by 50%, but had no significant effect on the enhanced release of the other hormones. These findings suggest that unusual properties of the plasma membrane of the PRL cell provide the basis for the unique response of the lactotrope to hypothalamic influences. (Endocrinology92: 1571, 1973)

In vitro trophin-releasing and inhibiting activities of certain purified fractions from bovine hypothalamus were apparently due primarily to the presence of divalent metals. The most abundant metal was copper which at concentrations less than 1 μg/ml markedly stimulated the release of all hormones. Zinc ion which was much less potent than copper, inhibited release of prolactin but stimulated release of the other hormones. Nickel, as low as 1 μg/ml, specifically inhibited prolcatin release; at much higher levels it enhanced release of the other hormones.

Bovine anterior pituitary slices were incubated in Krebs—Ringer—Bicarbonate for 2 hr and TSH, LH, FSH, ACTH, GH and prolactin (PRL) released into the medium were estimated by radioimmunoassay. During continuous incubation at 0 C, release of hormones was increased 10 to 60 times the release at 37 C, except for PRL release which was unaltered. A 5–min exposure to cold resulted, during subsequent incubation at 37 C, in a similar augmentation of release of all hormones including PRL. The enhanced release upon exposure to cold resulted in depletion of total cellular hormone stores by 8, 16, 21, 43, 45 and 61 percent for PRL, FSH, TSH, LH, GH and ACTH, respectively. A purified “prolactin—inhibiting factor” reduced the effect of the 5–min cold pulse on the release of PRL by 50%, but had no significant effect on the enhanced release of the other hormones. These findings suggest that unusual properties of the plasma membrane of the PRL cell provide the basis for the unique response of the lactotrope to hypothalami...

An experimental system for the continuous production of radioisotopic nitrogen, 13N2, has been developed using the sector-focused cyclotron at the University of Manitoba. The radioisotope is produced by 50 MeV proton bombardment of 14N2 with powdered melamine as the nitrogen-containing target material. A trap system necessary for the removal of unwanted reaction products is described and details of experimental procedures involving changes in proton beam current and in state of beam focus are presented.Using the radioisotope, a number of microorganisms isolated from sub-Arctic soils of the Fort Churchill region have been examined for their nitrogen fixation potential. Several of these, including a species of Rhodotorula and a species of Pullularia in addition to bacterial forms, have demonstrated nitrogen fixation at a rate comparable with that shown by Azotobacter vinelandii.