Efficacy of pamidronate in reducing skeletal events in patients with advanced multiple myeloma. Myeloma Aredia Study Group

BACKGROUND

Skeletal complications are a major clinical manifestation of multiple myeloma. These complications are caused by soluble factors that stimulate osteoclasts to resorb bone. Bisphosphonates such as pamidronate inhibit osteoclastic activity and reduce bone resorption.

METHODS

Patients with stage III multiple myeloma and at least one lytic lesion received either placebo or pamidronate (90 mg) as a four-hour intravenous infusion given every four weeks for nine cycles in addition to antimyeloma therapy. The patients were stratified according to whether they were receiving first-line (stratum 1) or second-line (stratum 2) antimyeloma chemotherapy at entry into the study. Skeletal events (pathologic fracture, irradiation of or surgery on bone, and spinal cord compression), hypercalcemia (symptoms or a serum calcium concentration > or = 12 mg per deciliter [3.0 mmol per liter]), bone pain, analgesic-drug use, performance status, and quality of life were assessed monthly.

RESULTS

Among 392 treated patients, the efficacy of treatment could be evaluated in 196 who received pamidronate and 181 who received placebo. The proportion of patients who had any skeletal events was significantly lower in the pamidronate group (24 percent) than in the placebo group (41 percent, P < 0.001), and the reduction was evident in both stratum 1 (P = 0.04) and stratum 2 (P = 0.004). The patients who received pamidronate had significant decreases in bone pain and no deterioration in performance status and quality of life. Pamidronate was tolerated well.

CONCLUSIONS

Monthly infusions of pamidronate provide significant protection against skeletal complications and improve the quality of life of patients with stage III multiple myeloma.

Long-term pamidronate treatment of advanced multiple myeloma patients reduces skeletal events. Myeloma Aredia Study Group

PURPOSE

To determine the efficacy and safety of 21 monthly cycles of pamidronate therapy in patients with advanced multiple myeloma.

PATIENTS AND METHODS

Patients with stage III myeloma and at least one lytic lesion received either placebo or pamidronate 90 mg intravenously administered as a 4-hour infusion monthly for 21 cycles. At study entry, the patients were stratified according to whether they were to receive first-line (stratum 1) or second-line (stratum 2) antimyeloma chemotherapy. Skeletal events (pathologic fracture, radiation or surgery to bone, and spinal cord compression) and hypercalcemia were assessed monthly.

RESULTS

The results of the first nine previously reported cycles are extended to 21 cycles. Of the 392 randomized patients, efficacy could be evaluated in 198 who received pamidronate and 179 who received placebo. After 21 cycles, the proportion of patients who developed any skeletal event was lower in the pamidronate-group (P = .015). The mean number of skeletal events per year was less in the pamidronate-group (1.3) than in placebo-treated patients (2.2; P = .008). Although survival was not different between the pamidronate-treated group and placebo patients overall, stratum 2 patients who received pamidronate lived longer than those who received placebo (14 v 21 months, P = .041). Pamidronate was safe and well tolerated during the 21 cycles of therapy.

CONCLUSION

Long-term monthly infusions of pamidronate as an adjunct to chemotherapy are superior to chemotherapy alone in reducing skeletal events in stage III multiple myeloma patients, and may improve the survival of patients on salvage therapy.

Humans can discriminate more than 1 trillion olfactory stimuli

Humans can discriminate several million different colors and almost half a million different tones, but the number of discriminable olfactory stimuli remains unknown. The lay and scientific literature typically claims that humans can discriminate 10,000 odors, but this number has never been empirically validated. We determined the resolution of the human sense of smell by testing the capacity of humans to discriminate odor mixtures with varying numbers of shared components. On the basis of the results of psychophysical testing, we calculated that humans can discriminate at least 1 trillion olfactory stimuli. This is far more than previous estimates of distinguishable olfactory stimuli. It demonstrates that the human olfactory system, with its hundreds of different olfactory receptors, far outperforms the other senses in the number of physically different stimuli it can discriminate.

Collagen; ultrastructure and its relation to mechanical properties as a function of ageing

Tail tendons from Fischer and Sprague-Dawly albino rats of ages from 2 weeks to 3 years were investigated under the polarizing microscope as regards structure and deformation behaviour. Periodically extinguishing bands were observed along the otherwise featureless tendons. By analysing the behaviour of this extinction pattern under appropriate rotations of the tendon, it could be deduced that the orientation of the basic birefringent units varies periodically along the tendon and that this periodic pattern corresponds to a planar arrangement of the anisotropic entities. All the relevant parameters of this periodic structure could be determined in a representative manner from polarizing optics alone. Subdivision of the tendons revealed regularly undulating or rather crimped subunits in good correspondence to what has been deduced from the extinction bands in the intact tendons. The crimp angle was found to decrease while the periodicity increased - in approximate proportion to the length of the tail - with the age of the rat implying constancy of crimp number during the life time of the animal. On elongation the periodicity was gradually removed. The calculated fibre elongation necessary to eliminate the crimp was in good agreement with observation for mature rats but was larger for young rats implying the simultaneous stretching of the fibre itself. Stress-strain properties of tendons were measured and models for crimp straightening were tested. It was found that a model containing inflexible hinges, corresponding to the ‘elastica’ problem in mechanics gave reasonable fit with experiment. Analysis of stress-strain data on this basis leads to a basic load bearing unit, the diameter of which increases from 100 to 500 nm with the age of the animal. Implications of these findings for the structure and properties of the tendons, also in relation to ageing are pointed out.

cGAS-STING drives ageing-related inflammation and neurodegeneration

Low-grade inflammation is a hallmark of old age and a central driver of ageing-associated impairment and disease1. Multiple factors can contribute to ageing-associated inflammation2; however, the molecular pathways that transduce aberrant inflammatory signalling and their impact in natural ageing remain unclear. Here we show that the cGAS-STING signalling pathway, which mediates immune sensing of DNA3, is a critical driver of chronic inflammation and functional decline during ageing. Blockade of STING suppresses the inflammatory phenotypes of senescent human cells and tissues, attenuates ageing-related inflammation in multiple peripheral organs and the brain in mice, and leads to an improvement in tissue function. Focusing on the ageing brain, we reveal that activation of STING triggers reactive microglial transcriptional states, neurodegeneration and cognitive decline. Cytosolic DNA released from perturbed mitochondria elicits cGAS activity in old microglia, defining a mechanism by which cGAS-STING signalling is engaged in the ageing brain. Single-nucleus RNA-sequencing analysis of microglia and hippocampi of a cGAS gain-of-function mouse model demonstrates that engagement of cGAS in microglia is sufficient to direct ageing-associated transcriptional microglial states leading to bystander cell inflammation, neurotoxicity and impaired memory capacity. Our findings establish the cGAS-STING pathway as a driver of ageing-related inflammation in peripheral organs and the brain, and reveal blockade of cGAS-STING signalling as a potential strategy to halt neurodegenerative processes during old age.

Assessment of function in routine clinical practice: description of the COOP Chart method and preliminary findings

The COOP Project, a primary care research network, has begun development of a Chart method to screen function quickly. The COOP Charts, analogous to Snellen Charts, were pretested in two practices on adult patients (N = 117) to test feasibility, clinical utility, and validity. Patients completed questionnaires containing validated health status scales and sociodemographic variables. Practice staff filled out forms indicating COOP Chart scores and clinical data. We held debriefing interviews with staff who administered the Charts. The results indicate the Charts take 1-2 minutes to administer, are easy to use, and produce important clinical data. The patterns of correlations between the Charts and validity indicator variables provide evidence for both convergent and discriminant validity. We conclude that new measures are needed to assess function in a busy office practice and that the COOP Chart system represents one promising strategy.

Long-term potentiation in the motor cortex

Long-term potentiation (LTP) is a model for learning and memory processes. Tetanic stimulation of the sensory cortex produces LTP in motor cortical neurons, whereas tetanization of the ventrolateral nucleus of the thalamus, which also projects to the motor cortex, does not. However, after simultaneous high-frequency stimulation of both the sensory cortex and the ventrolateral nucleus of the thalamus, LTP of thalamic input to motor cortical neurons is induced. This associative LTP occurs only in neurons in the superficial layers of the motor cortex that receive monosynaptic input from both the sensory cortex and the ventrolateral nucleus of the thalamus. Associative LTP in the motor cortex may constitute a basis for the retention of motor skills.

2-Aminopurine selectively inhibits the induction of beta-interferon, c-fos, and c-myc gene expression

The protein kinase inhibitor 2-aminopurine (2AP) blocks the induction of the human beta-interferon gene by virus or poly(I)-poly(C) at the level of transcription. This inhibition is specific, since 2AP does not inhibit induction of either the hsp70 heat-shock gene by high temperature or the metallothionein gene by cadmium or dexamethasone. However, 2AP does block the induction of the c-fos and c-myc proto-oncogenes by serum growth factors or virus, suggesting that a protein kinase may be involved in the regulation of these genes, as well as of the beta-interferon gene. However, different factors must be required for the induction of these three genes, since they are not coordinately regulated by the same inducers in most of the cell lines examined.

The Crystallization of Ultralong Normal Paraffins: The Onset of Chain Folding

The nature of chain folding in polymers and the determination of the chain length at which folding occurs have been central questions in polymer science. The study of the formation of lamellar polymer crystals through chain folding has received a new impetus as a result of the recent synthesis of normal alkanes of strictly uniform chain lengths up to C(390) H(782). Chain folding is found in all such paraffins starting with C(150)H(302). As with polyethylenes obtained by conventional polymerization, the fold length in the normal alkanes varies with crystallization temperature, but it is always an integral reciprocal of the full chain length. This behavior indicates that the methyl end groups are located at the lamellar surface and that the fold itself must be sharp and adjacently reentrant.

The ITS2 Database III--sequences and structures for phylogeny

The internal transcribed spacer 2 (ITS2) is a widely used phylogenetic marker. In the past, it has mainly been used for species level classifications. Nowadays, a wider applicability becomes apparent. Here, the conserved structure of the RNA molecule plays a vital role. We have developed the ITS2 Database (http://its2.bioapps.biozentrum.uni-wuerzburg.de) which holds information about sequence, structure and taxonomic classification of all ITS2 in GenBank. In the new version, we use Hidden Markov models (HMMs) for the identification and delineation of the ITS2 resulting in a major redesign of the annotation pipeline. This allowed the identification of more than 160,000 correct full length and more than 50,000 partial structures. In the web interface, these can now be searched with a modified BLAST considering both sequence and structure, enabling rapid taxon sampling. Novel sequences can be annotated using the HMM based approach and modelled according to multiple template structures. Sequences can be searched for known and newly identified motifs. Together, the database and the web server build an exhaustive resource for ITS2 based phylogenetic analyses.

Differential stable isotope labeling of peptides for quantitation and de novo sequence derivation

We have demonstrated the use of per-methyl esterification of peptides for relative quantification of proteins between two mixtures of proteins and automated de novo sequence derivation on the same dataset. Protein mixtures for comparison were digested to peptides and resultant peptides methylated using either d0- or d3-methanol. Methyl esterification of peptides converted carboxylic acids, such as are present on the side chains of aspartic and glutamic acid as well as the carboxyl terminus, to their corresponding methyl esters. The separate d0- and d3-methylated peptide mixtures were combined and the mixture subjected to microcapillary high performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). Parent proteins of methylated peptides were identified by correlative database searching of peptide tandem mass spectra. Ratios of proteins in the two original mixtures could be calculated by normalization of the area under the curve for identical charge states of d0- to d3-methylated peptides. An algorithm was developed that derived, without intervention, peptide sequence de novo by comparison of tandem mass spectra of d0- and d3-peptide methyl esters.