The degradation of serum amyloid A protein by activated polymorphonuclear leucocytes: participation of granulocytic elastase

To determine the role of inflammation in amyloidogenesis, we have studied the degradation of human serum amyloid A (SAA) protein by purified preparations of human blood polymorphonuclear leucocytes (PMN) and monocytes. When both PMN and monocytes were incubated in SAA-containing medium, the concentration of SAA as measured by a competitive anti-AA radioimmunoassay decreased over time. The rate of decrease of SAA was similar for both monocytes and PMN and there were no differences between four patients with amyloidosis and three normal controls. Resting PMN from normal volunteers were able to degrade SAA to smaller acid-soluble peptides within 16 hr while zymosan-activated PMN produced significant degradation within 1 hr (31%–50%). The supernatants from zymosan-treated PMN also caused marked SAA degradation within 1 hr.

The following enzyme inhibitors were able to prevent degradation of SAA by PMN supernatants; phenylmethylsulphonyl fluoride, a serine esterase inhibitor; α₁ anti-trypsin and soybean trypsin inhibitor; and acetyl-ala-ala-pro-val-chloromethyl ketone, an elastase inhibitor. The ability of a neutral lysosomal enzyme to degrade SAA was further confirmed by showing that purified PMN elastase significantly degraded ¹²⁵I-SAA.

We conclude that PMN contain one or more lysosomal enzymes capable of degrading SAA, an apoprotein of HDL₃ serum lipoproteins. Alteration in SAA proteolysis by activated PMN may contribute to the deposition of amyloid fibrils in the tissues of patients with chronic inflammatory disease.

     

Growth hormone co-treatment for ovulation induction may enhance conception in the co-treatment and succeeding cycles, in clonidine negative but not clonidine positive patients

To investigate the effect of co-treatment with growth hormone(GH) for ovulation induction with human menopausal gonadotrophins(HMG) on conception, we compared the pregnancy rate and responseto co-treatment with GH versus HMG/human chorionic gonadotrophin(HCG) alone in a prospective, randomized, cross-over protocolof volation induction for either in-vivo or in-vitro fertilization(IVF). The main outcome measures were the amount of gonadotrophinused and conception. Co-treatment with GH was associated witha reduction of 30% in gonadotrophin requirement. In 24 clonidinenegative patients 14 pregnancies were achieved (58.3%) eitherin the GH/HMG/HCG cycle or in the succeeding one. GH co-treatmentdid not generate any pregnancy in eight clonidine positive patients.We conclude that growth hormone may increase the pregnancy ratewhen combined with HMG/HCG for ovulation induction, not onlyin the co-treatment cycle but also in the succeeding one. Thebeneficial, synergistic effect of GH co-treatment was detectedin clonidine negative but not in clonidine positive infertilepatients.     

Na/P(i) cotransporter ( Npt2) gene disruption increases duodenal calcium absorption and expression of epithelial calcium channels 1 and 2

Mice homozygous for the disrupted type-II Na/P(i) cotransporter gene ( Npt2(-/-)) exhibit hypophosphataemia, increased serum concentration of 1,25-dihydroxyvitamin D (1,25-(OH)(2)D) and calcium (Ca) and elevated urinary Ca excretion. To determine whether the hypercalcaemia and hypercalciuria are secondary to 1,25-(OH)(2)D-stimulated intestinal Ca absorption, we examined the effect of Npt2 gene disruption on serum Ca and urinary Ca excretion after an overnight fast, and on duodenal Ca absorption. We also compared the duodenal expression of the epithelial Ca channels, ECaC1 and ECaC2, and calbindinD(9K) mRNAs, relative to that of beta-actin mRNA, in Npt2(+/+) and Npt2(-/-) mice. Both serum Ca and urine Ca/creatinine were significantly decreased in Npt2(-/-) mice after an overnight fast and were no longer different from that in wild-type mice. Absorption of (45)Ca from isolated duodenal segments in vivo and (45)Ca appearing in the plasma were significantly increased in Npt2(-/-) compared with Npt2(+/+) mice. In addition, the duodenal abundance of ECaC1, ECaC2 and calbindinD(9K) mRNAs was significantly elevated in mutant mice relative to that in wild-type mice. In contrast, both duodenal Ca absorption and ECaC1 and ECaC2 mRNA abundance were lower in mice with X-linked hypophosphataemia ( Hyp) than in normal littermates. In summary, we provide evidence for increased duodenal Ca absorption in Npt2(-/-) mice and suggest a role for ECaC1, ECaC2 and calbindinD(9K) in mediating this response.     

Renal expression of Na+-phosphate cotransporter mRNA and protein: Effect of the Gy mutation and low phosphate diet

The X-linked Gy mutation is closely linked, but not allelic, to Hyp and is characterized by rickets, hypophosphatemia, decreased renal tubular maximum for phosphate (Pi) reabsorption (Tm_P) and a specific reduction in renal brush-border membrane (BBM) Na⁺-Pi cotransport. Gy mice, like their normal littermates, respond to a low-Pi diet with an increase in BBM Na⁺-Pi cotransport, but fail to show an adaptive increase in Tm_p. Using an antibody raised against the NH₂ terminal peptide of the rat renal-specific Na⁺-Pi cotransporter (NaPi-2) and a NaPi-2 cDNA probe, we examined the effect of the Gy mutation and low-Pi diet (0.03% Pi) on NaPi-2 protein and mRNA abundance. The reduction in BBM Na⁺-Pi cotransport in Gy mice (51 ± 5% of normal, P < 0.05) was associated with a decrease in NaPi-2 protein (46 ± 12% of normal, P < 0.05) and mRNA abundance (76 ± 5%, P < 0.05). The low-Pi diet elicited a two- to three-fold increase in Na⁺-Pi cotransport in both normal and Gy mice that was accompanied by a large increase in NaPi-2 protein (10.2-fold in normal and 16.9-fold in Gy mice) and a modest increase in NaPi-2 mRNA (1.3-fold in both mouse strains, P < 0.05). The present data demonstrate that (1) the renal defect in BBM Pi transport in Gy mice can be ascribed to a deficit in NaPi-2 protein and mRNA abundance, (2) both normal and Gy mice respond to low Pi with an adaptive increase in NaPi-2 protein that exceeds the increase in Na⁺-Pi cotransport activity and NaPi-2 mRNA, (3) the adaptive increase in NaPi-2 protein and mRNA are not sufficient for the overall increase in Tm_P following Pi restriction. Received: 27 October 1995 / Received after revision: 4 December 1995 / Accepted: 6 December 1995     

Evaluation and standardization of polymerized ragweed extracts by chromatography,radioimmunoassay inhibition,and end point cutaneous titration

The standardization procedures for polymerized ragweed (PRW) must evaluate activity of PRW with assessments that differ from those used for standard unmodified extracts. This is because PRW allergens are different from conventional ragweed extracts in that they are much greater in average molecular weight and much lower in allergenicity for equivalent immunogenicity. We have evaluated seven samples of PRW for three parameters: allergenicity as determined by cutaneous end point titration, molecular weight distribution as determined by Sephadex G-200 chromatography, and availability of antigen E (AgE) determinants as measured by the ability of an extract to inhibit AgE binding to antibody by using a modification of the Farr technique. The skin test titers and molecular weight profiles provide information as to the safety of a PRW preparation and antigen-binding inhibitory activity gives information about allergenicity and immunogenicity. Appropriate limits may be set for each of these parameters to standardize PRW for clinical use.     

Loss of heterozygosity and mutational analyses of the ACTRII gene locus in human colorectal tumors

The activin type II receptorgene (ACTRII) is mutated in 58.1% of microsatellite-unstable (MSI-H) colorectal cancers and is a close relative of the TGFbeta-1 type II receptor, which is known to be involved in both MSI-H and non-MSI-H colorectal carcinogenesis. We therefore sought to determine whether ACTRII was involved in non-MSI-H colorectal cancers. We evaluated ACTRII inactivation by allelic deletion, loss of mRNA expression, or somatic mutation in 51 non-MSI-H colon cancers. Loss of heterozygosity (LOH) at the ACTRII locus (2q23.1) was found in 9 (17.6%) of 51 primary tumors. Loss of ACTRII mRNA expression was seen in one (14.3%) of the seven LOH-positive primary tumors from which total RNA was available. We also performed DNA sequencing analysis of tumors showing LOH. One LOH-positive primary tumor exhibited a novel germline missense sequence alteration (amino acid substitution, 117 Ile to Phe) that was not found in 23 additional normal individuals, implying that this alteration is not a frequent polymorphism. We conclude that ACTRII is probably involved in both non-MSI-H and MSI-H colorectal carcinogenesis, but more frequently in the latter subgroup.     

A Topographic study of differences in the P300 between introverts and extraverts

This paper presents results of a study to establish a link between neurocognitive psychophysiological and psychological type data through the investigation of differences in topographic auditory event-related potential (AERP) (P300) patterns in strongly introverted (n = 17) and strongly extraverted ( = 16) high school males as identified by the Myers Briggs Type Indicator. Group data files were created for the auditory event related potential task and converted to ASCII form. Amplitude values were evaluated at each scalp site. Kruskal Wallis one way analysis of variance was performed to evaluate group differences. In processing of infrequent, target stimuli, the amplitude of the P300 waveform for introverts was higher than for extraverts. When processing for non-target stimuli was subtracted from target stimuli, statistical differences were found over nine central, parietal, and occipital sites. The findings support and extend theories of biologically-based and bio-psycho-social typology.     

Polyribosomes of cells abortively or productively infected with adenovirus,papovavirus, or their hybrid

Summary The polyribosomes of African green monkey kidney (GMK) cells have been characterized during productive and abortive infections with adenovirus type 2, simian papovavirus SV40, and the PARA (defective SV40)-adenovirus type 2 hybrid. An early increase in uptake of H³-uridine was followed by a progressive decrease in both the amount of polyribosomes and in uptake of the label in all three systems that involved an adenovirus. Thus, the polyribosome distribution patterns obtained from GMK cells abortively infected with adenovirus type 2 did not differ significantly in optical density profile or incorporation of H³-uridine from the distributions obtained from GMK cells productively infected with either adenovirus 2 and SV40 or PARA-adenovirus type 2.A decrease in the amount of polyribosomes was not evident when GMK cells were infected with SV40. During the productive cycle of SV40 in GMK cells, the fifth (pentamer) polysome peak enlarged as the infection progressed. This increase was reflected both in increased optical density and incorporated H³-uridine. Material from this peak reacted with antibody to SV40 capsid antigen in the complement-fixation test. Arabinofurano-sylcytosine, a DNA inhibitor that blocks SV40 replication at a step prior to capsid formation, inhibited the formation of this peak. Treatment of the cellular extracts with EDTA or ribonuclease did not shift this peak to a lighter part of the gradient, along with the other polyribosomes. Virus particles, some of which proved to be infective for monkey cells, were present in electron micrographs of the pentamer peak.