Spinal anaesthesia and non-invasive positive pressure ventilation for hip surgery in an obese patient with advanced chronic obstructive pulmonary disease

We describe the use of non-invasive positive pressure ventilation combined with spinal anaesthesia to allow the insertion of a dynamic hip screw in an obese patient with advanced chronic obstructive pulmonary disease. The technique avoided the hazards of intubation and general anaesthesia in this high-risk patient.

Chromosome healing by addition of telomeric repeats in wheat occurs during the first mitotic divisions of the sporophyte and is a gradual process

Alien gametocidal chromosomes cause extensive chromosome breakage prior to S-phase in the first mitotic division of gametophytes lacking the alien chromosome. The broken chromosomes may be healed either by addition of telomeric repeats in the gametophyte or undergo fusions to form dicentric or translocation chromosomes. We show that dicentric chromosomes undergo breakage fusion-bridge (BFB) cycles in the first few mitotic divisions of the sporophyte, are partially healed before the germ line differentiation regimen, and are healed completely in the ensuing gametophytic stage. The gametocidal factor on chromosome 4Mg of Aegilops geniculata was used to induce dicentrics involving the satellite chromosomes1B and 6B of wheat, Triticum aestivum. The dicentrics 1BS x 1BL-2AL x 2AS and 6BS x 6BL-4BL x 4BS initiated BFB cycles that ceased 2 to 4 weeks after seed germination. At the end of the BFB cycles, we observed deficient 1B and 6B chromosomes with breakpoints in proximal regions of the 1BL and 6BL arms. The process of chromosome healing was analyzed in root tip meristems, at meiotic metaphase I, and in the derived progenies by fluorescence in-situ hybridization analysis using a telomeric probe pAtT4. The results show that chromosome healing in wheat occurs during very early mitotic divisions in the sporophyte by de-novo addition of telomeric repeats and is a gradual process. Broken chromosome ends have to pass through several cell divisions in the sporophyte to acquire the full telomeric repeat length.

Cross-regulatory interaction between Stra13 and USF results in functional antagonism

Transcription factors belonging to the basic helix-loop-helix (bHLH) family are critical regulators of cellular proliferation and differentiation. The functional activity of these proteins can be regulated by heterodimerization through the HLH domain, as a result of formation of functional or non-functional heterodimers. The presence of a leucine zipper in bHLH-leucine zipper (bHLHZip) proteins, however, prevents such heterodimeric interactions via the HLH domain between bHLH and bHLHZip proteins. To identify cellular proteins that directly interact with and modulate transcriptional repression mediated by the bHLH protein Stra13, we carried out a yeast two hybrid screen. The bHLHZip protein USF (Upstream Stimulatory factor) was identified as a Stra13 interacting protein. We demonstrate a direct interaction between Stra13 and USF that is dependent upon the C-terminal repression domain of Stra13 and the DNA-binding domain of USF. Stra13 and USF also colocalize and functionally interact in mammalian cells. Co-expression of USF abrogates Stra13-mediated repression of target genes and conversely, Stra13 inhibits DNA-binding and USF-mediated transactivation. Taken together, our data demonstrate that Stra13 and USF interact physically and functionally, and identify a novel mode of cross regulatory interaction between members of the bHLH and bHLHZip families that abrogates their functional activity.

A novel ATPase on mouse chromosome 7 is a candidate gene for increased body fat

A region of mouse chromosome 7, just distal to the pink-eyed (p) dilution locus, contains a gene or genes, which we have named p-locus-associated obesity (plo1), affecting body fat. Mice heterozygous for the most distally extending chromosomal deletions of this region have nearly double the body fat of mice when the deletion is inherited maternally as when it is inherited paternally. We have physically mapped the 1-Mb critical region, which lies between the Gabrb3 and Ube3a/Ipw genes, and DNA sequencing has localized a new member of the third subfamily of P-type ATPases to the minimal region specifying the trait. This gene, which we have called p-locus fat-associated ATPase (pfatp) is differentially expressed in human and mouse tissues with predominant expression in the testis and lower levels of expression in adipose tissue and other organs. We propose this ATPase as the prime candidate for the gene at the plo1 locus modulating body fat content in the mouse. The unusual inheritance pattern of this phenotype suggests either genomic imprinting, known to occur in other local genes (Ube3a, Ipw), or an effect of maternal haploinsufficiency during pregnancy or lactation on body fat in the progeny.

Bilin organization in cryptomonad biliproteins

The bilin organization of three cryptomonad biliproteins (phycocyanins 612 and 645 and phycoerythrin 545) was examined in detail. Two others (phycocyanin 630 and phycoerythrin 566) were studied less extensively. Phycocyanin 645 and phycoerythrin 545 were suggested to have one bilin in each monomeric (alphabeta) unit of the dimer (alpha2beta2) isolated from the others, and the remaining six bilins may be in pairs. One pair was found across the monomer-monomer interface of the protein dimer, and two identical pairs were proposed to be within the monomer protein units. For phycocyanin 612, a major surprise was that a pair of bilins was apparently not found across the monomer-monomer interface, but the remaining bilins were distributed as in the other two cryptomonad proteins. The effect of temperature on the CD spectra of phycocyainin 612 demonstrated that two of the bands (one positive and one negative) behaved identically, which is required if they are coupled. The two lowest-energy CD bands of phycocyanin 612 originated from paired bilins, and the two higher-energy bands were from more isolated bilins. The paired bilins within the protein monomers contained the lowest-energy transition for these biliproteins. Using the bilins as naturally occurring reporter groups, phycocyanin 612 was shown to undergo a reversible change in tertiary structure at 40 degrees C. Protein monomers were shown to be functioning biliproteins. A hypothesis is that the coupled pair of bilins within the monomeric units offers important advantages for efficient energy migration, and other bilins transfer energy to this pair, extending the wavelength range or efficiency of light absorption.

Signal transduction and activator of transcription (STAT) protein-dependent activation of angiotensinogen promoter: a cellular signal for hypertrophy in cardiac muscle

The role of the peptide hormone angiotensin (AngII) in promoting myocardial hypertrophy is well documented. Our studies demonstrate that AngII uses a signaling pathway in cardiac myocytes in which the promoter of the gene encoding its prohormone, angiotensinogen, serves as the target site for activated signal transduction and activator of transcription (STAT) proteins. Gel mobility-shift assay revealed that STAT3 and STAT6 are selectively activated by AngII treatment of cardiomyocytes in culture and bind to a sequence motif (St-domain) in the angiotensinogen promoter to activate its transcription in transient transfection assay. We have also observed a dramatic increase in the St-domain binding activity of STAT proteins in the hypertrophied heart of the genetically hypertensive rat relative to that of the aged-matched normotensive strain WKY, providing a compelling argument in favor of the linkage of STAT pathway to the heart tissue autocrine AngII loop. These studies thus uncover a mechanism by which the activation of a selective set of STATs underlies mobilization of the gene activation program intrinsic to cardiac hypertrophy.

Iron metabolism and human ferritin heavy chain cDNA from adult brain with an elongated untranslated region: new findings and insights

Ferritin is a ubiquitous protein which plays a major role in iron sequestration, detoxification and storage. In this paper we highlight the role of ferritin in iron homeostasis and describe factors and diseases that affect its expression. We also describe new studies which further characterize the structure and expression of a novel form of ferritin heavy (H) chain mRNA that was identified in brain and discuss possible implications of these findings. Human fetal and adult brain cDNA libraries previously were screened with cDNA for well-characterized liver ferritin H. In addition to 'liver-like' brain ferritin H cDNA, novel ferritin H cDNAs with an additional 279 nucleotide sequence at the 3'untranslated region (UTR) were identified in both libraries (see refs. 1 and 2; Dhar, M., Chauthaiwale, V., and Joshi, J. G., Gene, 1993, 126, 275 and Dhar, M., and Joshi, J. G., J. Neurochem., 1993, 61, 2140). However, relative to liver ferritin H cDNA, these novel cDNAs were incomplete at their 5'ends [see ref. 3; Joshi, J. G., Fleming, J. T., Dhar, M. S., and Chauthaiwale, V., J. Neurol Sci., 1995, 134, (Suppl.), 52]. In the present paper, by sequencing of cDNAs using reverse transcriptase polymerase chain reaction, we show that the 279 nt 3'UTR sequence, a coding sequence identical to that in human liver ferritin H, and a full-length 5'UTR that includes one mRNA regulatory iron-response element sequence, co-exist in at least one species of ferritin H transcript in six normal human adult and six late-onset, sporadic Alzheimer disease (AD) brains. This sequence is the same in the normal and AD brains. Dot-blot analysis of poly A+ RNAs from different human tissues indicates that relative to the coding sequence of ferritin H, expression of the 279 nt 3'UTR sequence varies among different tissues, is highest in the adult brain, and is very low in fetal brain. In normal adult hippocampus, ferritin H RNA with the novel 279 nt sequence localizes strongly to small non-neuronal cells, capillary endothelial cells, and to selected populations of neurons (granule cells of the dentate gyrus). Significant homology was observed between a region in the 279 nt 3'UTR segment of ferritin H RNA and the 3'UTR of cyclooxygenase-2 mRNA (an inducible iron-containing enzyme involved in prostaglandin synthesis). Possible functions for ferritin H protein derived from the novel message and for the elongated 3'UTR and 5'UTR are discussed.

Two distinct factor-binding DNA elements in cardiac myosin light chain 2 gene are essential for repression of its expression in skeletal muscle. Isolation of a cDNA clone for repressor protein Nished

The expression of the cardiac myosin light chain 2 (MLC2) gene is repressed in skeletal muscle as a result of the negative regulation of its transcription. Two regulatory elements, the cardiac specific sequence (CSS) located upstream (-360 base pairs) and a downstream negative modulatory sequence (NMS), which function in concert with each other, are required for repression of the MLC2 promoter activity in skeletal muscle. Individually, CSS and NMS have no effect. Transient transfection analysis with recombinant plasmids indicated that CSS- and NMS-mediated repression of transcription is position- and orientation-dependent and is transferable to heterologous promoters. A minimal conserved motif, GAAG/CTTC, present in both CSS and NMS, is responsible for repression as the mutation in the core CTTC sequence alone was sufficient to abrogate its repressor activity. The DNA binding assay by gel mobility shift analysis revealed that one of the two complexes, CSSBP2, is significantly enriched in embryonic skeletal muscle relative to cardiac muscle. In extracts from adult skeletal muscle, where the cardiac MLC2 expression is suppressed, both complexes, CSSBP1 and CSSBP2, were present, whereas the cardiac muscle extracts contained CSSBP1 alone, suggesting that the protein(s) in the CSSBP2 complex accounts for the negative regulation of cardiac MLC2 in skeletal muscle. A partial cDNA clone (Nished) specific for the candidate repressor factor was isolated by expression screening of the skeletal muscle cDNA library by multimerized CSS-DNA as probe. The recombinant Nished protein binds to the CSS-DNA, but not to DeltaCSS-DNA where the core CTTC sequence was mutated. The amino acid sequence of Nished showed a significant structural similarity to the sequence of transcription factor "runt," a known repressor of gap and pair-rule gene expression in Drosophila.

Descriptive epidemiology of childhood cancers in Bangalore, India

While fairly complete and reliable incident data on childhood cancers are available from the registries in India, mortality and survival information is not. Information concerning the latter was obtained by the Bangalore cancer registry through active follow-up involving visits to homes of patients. Between 1982 and 1989, 617 cases of cancers in childhood were registered, giving an age-standardized incidence rate of 84.8 and 48.4 per million in male and female children, respectively. Active follow-up provided mortality/survival information in 532 or 86.2 percent of these cases. Overall, observed five-year survival was 36.8 percent (both genders combined) with a relative survival of 37.5 percent when childhood mortality in the general population was taken into account. The five-year relative survival was best for thyroid carcinoma (100 percent) followed by Hodgkin's disease (73 percent) and retinoblastoma (72.9 percent). Survival was comparatively low, being 9.9 percent in acute nonlymphatic leukemia and less than 20 percent in rhabdomyosarcoma and the category grouped as 'other malignant neoplasms.' Survival in Hodgkin's disease was influenced by clinical stage at presentation, but was not statistically significant possibly due to small numbers.

Importance of anatomical subsite in correlating risk factors in cancer of the oesophagus--report of a case--control study

In Bangalore, cancer of the oesophagus is the third most common cancer in males and fourth most common in females with average annual age-adjusted incidence rates of 8.2 and 8.9 per 100,000 respectively. A case-control investigation of cancer of the oesophagus was conducted based on the Population-based cancer registry, Bangalore, India. Three hundred and forty-three cases of cancer of the oesophagus were age and sex matched with twice the number of controls from the same area, but with no evidence of cancer. Chewing with or without tobacco was a significant risk factor. In both sexes chewing was not a risk factor for cancer of the upper third of the oesophagus. Among males, non-tobacco chewing was a significant risk factor for the middle third but not for the other two segments and tobacco chewing was a significant risk factor for the lower third of the oesophagus, but not for the other two segments. Bidi smoking in males was a significant risk factor for all three segments being highest for the upper third, less for the middle third and still less for the lower third. The risk of oesophageal cancer associated with alcohol drinking was significant only for the middle third.

Quantification of cardiac and tissue iron by nuclear magnetic resonance relaxometry in a novel murine thalassemia-cardiac iron overload model

OBJECTIVE

To determine whether nuclear magnetic resonance (NMR) relaxation parameters can be used to quantify iron in tissues, the relationship between NMR spectrometric T2 relaxation measurements and tissue iron concentration were verified in a novel murine cardiac iron overload model.

METHODS

Congenital heterozygous thalassemic mice and controls were injected with intraperitoneal iron or saline and were sacrificed at three weeks. Samples of liver, heart and peripheral muscle were subjected to NMR relaxation measurements and continuous distribution analysis. Tissue ferritin levels were determined with immunoadsorbance techniques, and elemental iron was assayed by flame atomic absorption. Tissues were analyzed pathologically with hematoxylin and eosin and Prussian blue staining to confirm the localization of iron.

RESULTS

This murine iron loading model was uniquely successful in loading iron into the major organs, especially the heart, and produced significant reductions in T1 and T2 NMR relaxation values. There was a good correlation between soluble ferritin and total iron levels (r=0.92), indicating that there is a constant and significant fraction of total iron present in ferritin irrespective of absolute iron concentrations. Regression analysis between total iron content and T2 relaxivity showed a linear relationship (r=0.96), suggesting that the T2 relaxation parameter is related to tissue iron concentration. The regression relationship suggested that NMR can detect iron levels as low as 0.1 mg/g of tissue.

CONCLUSIONS

Parenteral iron loading in mice produces unique iron overload in major organs, including the heart. Local iron deposition is detectable by NMR relaxometry at 0.1 mg/g or higher. There is a linear relationship between iron concentration and T2 relaxivity. Thus, NMR may be an important and useful clinical tool to quantify iron excess in various pathobiological states of human disease due to iron overload, including heart disease.

Incidence of gastroesophageal reflux with whey- and casein-based formulas in infants and in children with severe neurological impairment

Ten exclusively gastrostomy-fed, neurologically impaired children (4.5-14.5 years old) with gastroesophageal reflux were randomly assigned to receive feedings with either a casein- or a whey-based formula for 48 h each and then crossed over to the other formula. One 24-h pH probe study each was performed while being fed casein- and whey-based formula, respectively. There was a significant reduction in episodes and duration of gastroesophageal reflux while consuming the whey-based formula (p < 0.05). Whey-based feedings should be considered an additional tool in conjunction with other antireflux measures to treat gastroesophageal reflux more effectively in children with severe neurological impairment. A similar study was also conducted involving 14 infants (3-12 months old) with documented gastroesophageal reflux using 24-h pH probe monitoring while consuming a casein-based formula. The formula was changed to a whey-based formula and the pH probe study repeated within 3-5 days. Four infants showed improvement and the rest showed either deterioration (1/14) or comparable results (9/14). The reduction in the mean number of episodes or duration of gastroesophageal reflux with the whey-formula was not significantly different from that with the casein-based formula (p > 0.05). Based on these findings, generalized recommendations for the use of whey-based formula in infants with gastroesophageal reflux cannot be made.

A novel ferritin heavy chain messenger ribonucleic acid in the human brain

In the aging human brain, the concentrations of iron and its major storage protein, ferritin, rise but the distribution of metal and protein remains non-uniform. More ferritin could be isolated from the brains of humans who died of Alzheimer's disease (AD) than from age- and sex-matched controls. Also, brain ferritin of rats chronically exposed to aluminum chloride in their drinking water contained more aluminum and iron. Based on these earlier observations, a more detailed study of human brain ferritin was initiated. The results showed that ferritin is a component of neuritic (senile) plaques in AD. Ferritin obtained from normal or AD brains is composed of 24 subunits (70% heavy (H) chain; 30% light (L) chain). With high performance liquid chromatography, the subunits resolved into a cluster of four H-chain peaks and one major L-chain peak. Western blot analysis confirmed the identity of H- and L-fractions. The techniques of molecular biology revealed the presence of an additional ferritin messenger ribonucleic acid (mRNA) species for the H subunit which was more abundant in the brain than in other human tissues. It contained the entire sequence of 919 nucleotides of H chain mRNA from liver but also an additional segment of 279 nucleotides in the 3'-untranslated region. The two mRNA seemed to arise by the use of an alternate polyadenylation site of the same primary transcript. Ribonuclease protection assays revealed that the concentrations of the longer mRNA in the normal hippocampus and the hippocampus of patients with AD brains were similar.

A case-control investigation on cancer of the ovary in Bangalore, India

Cancer of the ovary is the sixth leading cancer among females in Bangalore, and is a leading site of cancer in other population-based cancer registries in India. A case-control investigation was conducted utilizing the data from the population-based cancer registry in Bangalore. In addition to the core patient information, certain other details pertaining to consumption of tobacco, reproductive and obstetric factors and those related to the practice of family planning, including the method adopted, were available with the registry, for the period 1982-1985. Identical information was also available for patients residing in the registry area who did not have cancer. Ninety-seven cases of ovarian cancer in ever-married women were age-matched with 194 controls from the same area who showed no evidence of cancer. The risk of ovarian cancer was not influenced by tobacco habits, alcohol consumption, diet or the various reproductive factors. However, tubectomy as a method of family planning appeared to reduce the risk of development of ovarian cancer. This reduction in risk was not influenced by parity or age of the woman at the time of birth of the first child.

Survival in breast cancer: a population-based study in Bangalore, India

Survival from cancer reflects the aggressiveness of the disease, the effectiveness of treatment and host factors such as age. While hospital-based survival rates are typically used to evaluate the care provided in a particular hospital, population-based survival reflects the effectiveness of the overall cancer control strategy in the region. Here, we report the survival experience of 1514 breast cancer patients registered by the Bangalore population-based registry during 1982-1989. There have been very few reports on survival from cancer in India, mainly because of poor patient follow-up and inadequate system of registration of death. This has been largely overcome in this study by means of active follow-up through visits of homes of patients. Scrutiny of medical records and matching with death certificates, was also carried out in a small proportion (12%) of cases. Thus, information on vital status (whether dead or alive) as on January 1, 1993 was available for 1334 (88%) subjects and partial follow up data were available for a further 34 (2%). The observed 5 year survival was 42.3% and the corresponding relative survival was 46.8%. The observed survival was 57.4% for localized disease, 45.8% for direct extension, 37% for those with regional node involvement, 14.2% for distant metastasis and 38.3% for those with unstaged disease. The clinical extent of disease and the educational status were independent predictors of survival.

Purification and characterization of Phaseolus vulgaris alpha-D-galactosidase isozymes

A highly purified preparation of alpha-D-galactosidase [E.C. 3.2.1.22] isozymes was obtained from Phaseolus vulgaris (pinto bean) seeds by extraction, salt precipitation, ion exchange, and affinity chromatography. The final preparation was homogeneous by SDS-PAGE but revealed isozymes of relative mass of 38.3 and 39.6 kDa. The N-terminal sequence for both isozymes was identical, LANGLAKT (one letter code for amino acids). Relative native molecular mass was estimated at 149.3 kDa by Sephacryl S-200 chromatography. Activity was unaffected by ionic strength at high enzyme concentrations, and was specific for alpha-D-galactoside conjugates. No protease or hemagglutinin activity was detected, and activity was stable at 4 degrees C. Studies with soluble oligosaccharides demonstrated high activity against the selected straight and branched-chain substrates. The enzyme was active against terminal alpha 1-3 galactosyl residues on human and rabbit erythrocyte membranes. Because of its activity against membrane glycoconjugates, these isozymes may have potential utility for modifying membrane epitopes on native erythrocytes.

Iron and aluminum homeostasis in neural disorders

The brain is the most compartmentalized organ. It is also highly aerobic. Because nerve cells grow but do not regenerate, the brain is the organ best suited for the accumulation of metabolic errors colocalized in specific areas of the brain over an extended period. Alzheimer's disease (AD) is primarily a neurological disorder of the elderly. It is suggested that this disorder results from the accumulation of such errors, and that AD onset aluminum and iron contribute to but do not necessarily initiate the onset of the disease. In vitro and in vivo evidence summarized here suggests that this is effected by interfering in the utilization of glucose and glucose-6-phosphate, and sequestration of iron by ferritin. beta-amyloid precusor proteins (beta-APPs) are normal components of the human brain and some other tissues. Proteolysis of these, presumably by serine proteases, generates a 39 to 42 amino acid long peptide, the alpha-amyloid (beta-AP). In AD brains, beta-AP aggregates into plaque, the hallmark of AD brains. Some of the alpha-APPs also contain a 56 amino acid long segment which inhibits serine proteases. We show that in vitro, at pH 6.5, aluminum activates beta-chymotrypsin 2-fold and makes it dramatically resistant to protease inhibitors such as bovine pancreatic trypsin inhibitor (bPTI) or its mimic present in the beta-amyloid precursor proteins (beta-APPs). Iron and oxygen are reported to favor cross-linking of beta-AP in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequence of a cDNA encoding the ferritin H-chain from an 11-week-old human fetal brain

A cDNA library in lambda Charon BS(-) from 11-week-old human fetal brain (FB) was screened using a human liver ferritin (FTH)-encoding cDNA as a probe. The complete sequence of the positive clone, cFB1, showed that the coding region and a part of the 5' and 3' untranslated regions (UTR) are identical to the corresponding published sequence of the liver cDNA. However, a particularly noteworthy difference is the presence of 279 bp of additional sequence in the FB 3'-UTR. Northern blot analysis of FB poly(A)+RNA showed it to be a part of the FTH transcript. Comparison of the 279-bp sequence with the GenBank and EMBL databases showed it to be 94.1, 62.5, and 58.9% similar to segments from human, mouse and rat FTH genomic sequences, respectively. However, in all these cases, only a part of this 279-bp sequence has been found in the nontranscribed region. We therefore conclude that in FB, the 279-bp sequence is a part of the mature FTH mRNA. Sequence analysis also suggests a differential poly(A) site selection in the production of FTH mRNA in FB and liver.