Effects of prevention of coprophagy on pregnant mice--is coprophagy beneficial on a balanced diet?

The effects of prevention of coprophagy on reproductive performance were examined in ICR mice. Females were treated with restrainers in order to prevent them from ingesting their feces from day 1 through day 17 of pregnancy. The restrained animals fed a commercial diet did not show any clear adverse effects. In contrast, restrained dams fed a purified diet deficient in vitamin B12 exhibited stillbirths (14%) and abortions (7%). Restrained dams fed a diet lacking in vitamin B12 and folic acid also experienced frequent abortions (27%). In addition, six out of 14 restrained dams (43%) aborted when fed a vitamin B complex-deficient diet. Sham-restrained animals, fed the vitamin B complex deficient-diet, but able to ingest their feces trapped by smaller-mesh floors, escaped these adverse effects. Sham-restrained animals fed the commercial diet, however, showed only a slight improvement in their reproductive performance. In conclusion, coprophagy has nutritional significance as long as the diet is lacking at least B vitamins, especially vitamin B12 and folic acid, whereas it almost entirely loses its nutritional significance when the mouse has access to a balanced diet such as the one made available to the laboratory mice in the present study.     

A temperature-sensitive mutant of Escherichia coli with an altered RNA polymerase beta' subunit.

$\text{Penicillium charlesii}$ extracts contain UDP-galactose:NAD⁺ 2-hexosyl oxidoreductase (1). ADP-ribose also serves as a substrate resulting in formation of NADH and an oxidized ADP-ribose derivative. Treatment of the oxidized product with NaBH₄ followed by hydrolysis at pH 2 and 100° releases xylose as well as ribose. We conclude that ADP-D-$\text{glycero}$-D-$\text{glycero}$-3-pentosulose (ADP-3-ketoribose) is the product derived from ADP-ribose.     

Interaction between lymphocytes and inflammatory exudate cells. II. A proteolytic enzyme released by PMN as a possible mediator for enhancement of thymocyte response.

Mouse polymorphonuclear leukocytes (PMN) were harvested from the peritoneal cavity stimulated with sodium caseinate. The cells were cultivated in vitro and the supernatant of these cultures (SUP) was tested for enhancing potency on DNA synthesis by syngeneic thymocytes stimulated with phytohemagglutinin (PHA). The enhancing potency of the SUP was markedly influenced by duration of the donor cultures of PMN, population density of the cultures, and protein concentrations in the medium, respectively. The enhancing factor in the SUP was found to be non-dialysable, heat-labile, and stable in the pH ranging between 3 and 9 but labile in the pH below 2 or above 10; its m.w. was approximately 19.000 when measured by gel-filtration on Sephadex G-75. The factor had a proteolytic activity on 3H-acetyl hemoglobin (3HHb) at neutral pH (7.2). Both the proteolytic activity and thymocyte-helping potency of the SUP were similarly abolished by adding protease inhibitor (Trasylol) in soluble form, or by passing through a column of the inhibitor insolubilized. It was thus assumed that the enhancing effect of PMN on thymocyte response was associated with a neutral protease released from the cells: it may be termed a lymphocyte-helping protease (LHP).     

Direct contractile effect of motilin on isolated smooth muscle cells of guinea pig small intestine.

We examined the direct effect of motilin on longitudinal and circular smooth muscle cells isolated from the guinea pig small intestine. In addition, the effects of 8-(N,N-diethylamino)-octyl-3,4,5-trimethoxy-benzoate hydrochloride (TMB-8, an inhibitor of intracellular Ca(2+)-release), verapamil (a voltage-dependent Ca(2+)-channel blocker), and removal of extracellular Ca2+ were investigated to evaluate the role of intracellular Ca2+ stores and extracellular Ca2+ on the muscle contraction induced by motilin. The effects of atropine (a muscarinic receptor antagonist), spantide (a substance P receptor antagonist) and loxiglumide (a CCK-receptor antagonist) were also examined to determine whether the motilin-induced contraction was independent of those receptors. Motilin induced a contraction of the longitudinal and circular smooth muscle cells in a dose-dependent manner with the maximal effect attained after 30 seconds of incubation. The ED50 values were 0.3 nM and 0.05 nM, respectively. TMB-8 suppressed completely the motilin-induced contraction of both types of smooth muscle cells. Verapamil had only a slight suppressive effect. Removal of extracellular Ca2+ did not have any significant influence on motilin-induced contraction. The contractile response to motilin was not affected by atropine, spantide or loxiglumide. Our findings showed that:1) motilin has a direct contractile effect on both longitudinal and circular smooth muscle cells; 2) this contractile effect is not evoked via muscarinic, substance P or CCK receptors, and 3) the intracellular release of Ca2+ plays an important role in the contractile response to motilin on both types of smooth muscle cells.     

Replacement of L-T4 suppository in MMI treated rabbits

L-T4 suppositories containing 50, 100 or 200 micrograms of L-T4 were given to rabbits treated with MMI. The serum T4 gradually increased within 3.5 and 6.5 hours following the use of 100 and 200 micrograms of L-T4 suppositories, respectively, without an acute increase in serum T3. The increase in serum T4 continued up to 48 hours. The area under the curve (AUC) for serum T4 was evidently dose-dependent. It is concluded from these results that the T4 suppository will be useful as a replacement therapy for patients with hypothyroidism.     

Release of neuropeptide Y from pheochromocytomas

To investigate the release of neuropeptide Y (NPY) from the pheochromocytomas, we studied the relationship between the plasma and tumor tissue immunoreactive (IR) NPY concentrations in 13 patients with pheochromocytoma and measured the IR-NPY concentration in plasma samples obtained by catheter from several veins (jugular veins, superior vena cava, renal veins, adrenal veins and inferior vena cava) in 2 patients with pheochromocytoma. The plasma IR-NPY concentration in 13 patients with pheochromocytoma ranged from 118 to 1460 pg/ml and the concentration in 10 of 13 patients with pheochromocytoma was above 290 pg/ml (the upper limit of normal range). The tumor tissue IR-NPY ranged from 0.025 to 95.3 micrograms/g wet tissue. Plasma IR-NPY was parallel with tumor tissue IR-NPY in 13 cases of pheochromocytoma (r = 0.76, P less than 0.01). The highest concentration of IR-NPY was found in plasma obtained from the drainage vein from a tumor among the plasma samples obtained from several veins in 2 cases of pheochromocytoma. These findings indicate that in patients with pheochromocytoma, NPY is in most cases excessively released from the tumors into the systemic circulation and plasma IR-NPY in the periphery is increased.     

Purification of the E. coli dnaA gene product.

The product of the dnaA gene of Escherichia coli was isolated in a highly enriched form. The purification product binds specifically to DNA containing the E. coli chromosomal origin of replication, oriC.     

Histamine-producing bacteria in decomposing skipjack tuna (Katsuwonus pelamis).

Spoilage in skipjack tuna (Katsuwonus pelamis) was studied under controlled conditions by incubating whole, fresh fish in seawater at 38 degrees C, the optimum temperature for histamine formation. Bacterial isolates were obtained from the loin tissue of a decomposing tuna containing 134 mg of histamine per 100 g and a total anaerobic count of 3.5 x 10(5)/g after incubation for 24 h. Over 92% of the 134 isolates obtained were facultatively or obligately anaerobic bacteria. Eighteen isolates produced histamine in culture media containing histidine, and these were identified as Clostridium perfringens, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, and Vibrio alginolyticus. Histidine decarboxylase activity of several isolates was measured in a tuna broth medium and with resting cells suspended in a buffered histidine solution.     

A second novel dye-linked L-proline dehydrogenase complex is present in the hyperthermophilic archaeon Pyrococcus horikoshii OT-3

Two distinguishable activity bands for dye-linked l-proline dehydrogenase (PDH1 and PDH2) were detected when crude extract of the hyperthermophilic archaeon Pyrococcus horikoshii OT-3 was run on a polyacrylamide gel. After purification, PDH1 was found to be composed of two different subunits with molecular masses of 56 and 43 kDa, whereas PDH2 was composed of four different subunits with molecular masses of 52, 46, 20 and 8 kDa. The native molecular masses of PDH1 and PDH2 were 440 and 101 kDa, respectively, indicating that PDH1 has an alpha4beta4 structure, while PDH2 has an alphabetagammadelta structure. PDH2 was found to be similar to the dye-linked l-proline dehydrogenase complex from Thermococcus profundus, but PDH1 is a different type of enzyme. After production of the enzyme in Escherichia coli, high-performance liquid chromatography showed the PDH1 complex to contain the flavins FMN and FAD as well as ATP. Gene expression and biochemical analyses of each subunit revealed that the beta subunit bound FAD and exhibited proline dehydrogenase activity, while the alpha subunit bound ATP, but unlike the corresponding subunit in the T. profundus enzyme, it exhibited neither proline dehydrogenase nor NADH dehydrogenase activity. FMN was not bound to either subunit, suggesting it is situated at the interface between the alpha and beta subunits. A comparison of the amino-acid sequences showed that the ADP-binding motif in the alpha subunit of PDH1 clearly differs from that in the alpha subunit of PDH2. It thus appears that a second novel dye-linked l-proline dehydrogenase complex is produced in P. horikoshii.