13/14 translocation in a man with reproductive failure

Summary An inherited (maternal origin) 13/14 translocation with the nucleolus organizer regions eliminated and one centromere was found in an oligospermic man whose wife had had two spontaneous abortions. Meiotic studies revealed all stages of spermatogenesis with a trivalent configuration in diakinesis. Possible reasons for his subfertility and his mother's normal fertility are discussed.     

Effect of glucose on protein phosphorylation in rat pancreatic islets

Isolated rat pancreatic islets, incubated in the presence of extracellular ³²Pi to steady state ³²P incorporation into cellular phosphopeptides, were exposed to glucose for 10 min. Glucose (16.7 mM) significantly stimulated the phosphorylation of six phosphoproteins with molecular weights of 15,000, 35,000, 49,000, 64,000, 93,000 and 138,000. Mannoheptulose (16.7 mM) markedly inhibited glucose-stimulated phosphorylation of these six phosphoproteins. This protein phosphorylation might be important in mediating glucose-stimulated insulin release.     

Protein-lipid interactions. A nuclear magnetic resonance study of sarcoplasmic reticulum Ca2,Mg2+-ATPase, lipophilin, and proteolipid apoprotein-lecithin systems and a comparison with the effects of cholesterol.

Deuterium Fourier transform nuclear magnetic resonance (NMR) spectra at 34 MHz (corresponding to a magnetic field strength of 5.2 T) have been obtained of a variety of protein-lipid systems containing specifically deuterated phospholipids. The following systems were investigated as a function of temperature: sarcoplasmic reticulum ATPase (ATP phosphohydrolase, EC 3.6.1.3) complexed with 1-myristoyl-2-(14,14,14-trideuteriomyristoyl)-sn-glycero-3-phosphocholine (DMPC-d3) or 1,2-bis(16,16,16-trideuteriopalmitoyl)-sn-glycero-3-phosphocholine (DPPC-k6); human brain lipophilin complexed with DPPC-d6 or 1,2-bis(6,6-dideuteriopalmitoyl)-sn-glycero-3-phosphocholine (DPPC-6,6-d4); beef brain myelin proteolipid apoprotein (PLA) reconstituted with DMPC labeled as CD2 (or CD3) at one or more of positions 3, 4, 6, 8, 10, 12, or 14 of the sn-2 chain. For purposes of comparison, spectra were also obtained for bilayers containing cholesterol (CHOL). The results show that proteins either disorder or have little effect on hydrocarbon chain order in membranes above the gel to liquid-crystal phase transition temperature (Tc) of the pure lipids. Cholesterol, however, causes a very large ordering of the hydrocarbon chains above Tc, but both cholesterol and protein prevent chain crystallization (by effectively disordering chain packing) immediately below Tc. No evidence for any ordered "boundary lipid" in association with protein was found above Tc, perhaps due to the rough nature of protein surfaces. Above Tc, exchange between free bilayer and protein associated lipid is fast on the time scale of the deuterium NMR experiment (greater than or similar to 10(3) s-1). We have also obtained proton-decoupled phosphorus-31 nuclear magnetic resonance spectra at 60.7 MHz (corresponding to a magnetic field strength of 3.5 T) of DMPC, DMPC-AT-Pase, and DMPC-CHOL complexes. The results indicate that ATPase and CHOL CAUSE SMALL DECREASES IN 31P chemical shielding anisotropies but that in addition ATPase causes a four- to fivefold increase in 31P spin-lattice and Carr-Purcell spin-spin relaxation rates, suggesting the possibility of polar group protein-lipid interaction leading to increased correlation times in the region of the lipid phosphate head group.     

Chromosome polymorphism in populations of the grasshopper Trimerotropis pallidipennis from southern Argentina

Three populations of the grasshopper Trimerotropis pallidipennis from southern Argentina have been studied cytologically. A very characteristic B-chromosome was found in all three. They also showed geographical variability in respect of the presence of pericentric inversions, and the inversion system was found to influence chiasma frequency. The Laguna Blanca population, which is on the hypothetical pathway the species is believed to have followed during its migration from northern to southern latitudes, has the same karyotype composition as the N. American form, with fixed inversions in the 3 largest autosomes and the X-chromosome. Its members have a high total chiasma frequency and a great number of interstitial chiasmata. The Sierra de la Ventana population, situated at the absolute eastern border of the species distribution is highly polymorphic with respect to the presence of inversions in the medium chromosomes. Its members have the lowest total chiasma frequency and a greatly reduced number of interstitial chiasmata. Situated geographically between the other two, the Choele-Choel population has the highest frequency of inversions and many of them are homozygous. Its members have a higher total chiasma frequency than that observed in specimens from Sierra de la Ventana, and a greatly reduced number of interstitial chiasmata, similar to that observed in individuals from the latter population.     

Importance of the flux of phosphate across the inner membrane of kidney mitochondria for the activation of glutaminase and the transport of glutamine

The effect of mersalyl, an inhibitor of phosphate transport across the inner mitochondrial membrane, was investigated on the uncoupled respiration of pig kidney mitochondria in the presence of glutamine as substrate and on the activity of the phosphate-dependent glutaminase in the intact organelles. In addition, the submitochondrial location of the enzyme was reinvestigated.

1. (1) It was found that mersalyl completely inhibits uncoupled respiration of the mitochondria in the presence of glutamine as substrate, whereas respiration with glutamate was not affected. The same amount of mersalyl which inhibits coupled oxidation of glutamine also inhibits coupled oxidation of glutamate and some other substrates.

2. (2) Mersalyl strongly inhibited the activation of glutaminase in intact mitochondria only in the presence of inhibitors of electron transport or of an uncoupler. The addition of a detergent prevented or fully released the inhibition. The effect of mersalyl was observed even when the mitochondria were pre-incubated with phosphate or incubated in the phosphate-free medium. If mersalyl and carbonyl cyanide m-chlorophenylhydrazone (CCCP) were added 3 min after pre-incubation with phosphate the same intramitochondrial concentration of the anion as in control experiments was found, whereas the activity of glutaminase was severely inhibited. These findings suggest that the activation of the enzyme by phosphate in intact nonenergized mitochondria occurs only if the activator moves across the inner mitochondrial membrane.

3. (3) Mersalyl (plus CCCP) markedly decreased [¹⁴C]glutamine- and [³²P]-phosphate-permeable mitochondrial spaces. A close correlation between the decrease of phosphate and glutamine permeable spaces and the inhibition of glutaminase activity was found.

4. (4) If the activation energy of the enzyme was determined with frozen mitochondrial preparations, a discontinuity or break in the Arrhenius plot was observed, whereas the presence of a detergent completely abolished the break. Digitonin or ultrasonic treatment of the mitochondria followed by separation of the membrane and the soluble fraction revealed that glutaminase is a membrane-bound enzyme.

On the basis of these findings it is concluded that there is an association between the transport of phosphate on one side and the transport of glutamine and glutaminase activity on the other. It is possible that the movement of phosphate across the membrane activates the enzyme which facilitates diffusion of glutamine down a concentration gradient. However, the existence of a specific glutamine-phosphate carrier is not ruled out.     

Cell cooperation in abolition of tolerance of xenogeneic tumor.

Thymectomized, lethally irradiated mice reconstituted with syngeneic bone marrow cells are tolerant to xenogeneic Yoshida ascites sarcoma (YAS). The tolerance was abolished by an injection of syngeneic normal spleen, thymus, or lymph node cells given simultaneously with YAS. Allogeneic and semiallogeneic spleen cells were ineffective. The YAS-rejecting mice produced specific anti-tumor antibodies. The serum of these mice transferred to tolerant T-cell-deficient mice protected the latter from inoculated YAS cells. These serum-protected mice were not able to resist the reinoculum of the tumor cells as the mice restored with lymphoid cells did. The latter mice rejected the YAS at the time when donor cells were practically absent in their lymphoid tissue. The low effective ratio of injected syngeneic lymphoid to tumor cells, efficiency of injected thymus cells, and other data led to the conclusion that transferred lymphoid cells did not act directly on tumor cells but through cooperation with host lymphoid cells. The cooperation of donor T- and host B-lymphocytes enabled the activation of the latter, and YAS cells were rejected.     

Synthesis and chemical behaviour of D-glucosyl esters of glutamic acid having the side-chain carboxyl group involved in the glycosidic linkage.

Simultaneous and stepwise deprotection of the fully benzylated D-glucosyl esters of 1-benzyl N-benzyloxycarbonyl- and N-tert-butyloxycarbonyl-L-glutamic acid (1 and 5, respectively) have been examined. Catalytic hydrogenation of 1 led to intramolecular aminolysis to give pyroglutamic acid and D-glucose, but similar treatment in the presence of trifluoroacetic acid afforded both anomers of 1-O-(L-gamma-glutamyl)-D-glucopyranose, which were characterized as trifluoroacetates (2alpha and 2beta) and converted into 2,3,4,6-tetra-O-acetyl-1-O-[1-methyl N-(acetyl)-L-glutam-5-oyl]-D-glucopyranose (4) which was also prepared by a definitive method. Hydrogenolysis of 5 gave both anomers of 1-O-[N-(tert-butyloxycarbonyl)-L-gamma-glutamyl]-D-glucopyranose (6), which, upon treatment with trifluoroacetic acid at - 10 degrees, afforded 2alpha and 2beta, respectively. The structure of 6beta was established by its conversion into 2,3,4,6-tetra-O-acetyl-1-O-[1-methyl N-(tert-butyloxycarbonyl)-L-glutam-5-oyl]-beta-D-glucopyranose (7beta), whereas similar treatment of 6alpha gave a mixture of 1,3,4,6-tetra-O-acetyl-2-O-[1-methyl N-(tert-butyloxycarbonyl)-L-glutam-5-oyl]-alpha-D-glucopyranose (9) and 7alpha. A 1 leads to 2 acyl migration occurred during esterification of the aglycon carboxyl group of 6alpha with diazomethane to give 2-O-[1-methyl N-(tert-butyloxycarbonyl)-L-glutam-5-oyl]-alpha-D-glucopyranose (8).