Accuracy of cold sensibility testing on teeth with full-coverage restorations: a clinical study.

AIM: This clinical study evaluated the reliability of the 1,1,1,2-tetrafluoroethane (Endo Ice) cold test to determine the pulpal diagnosis of teeth with full-coverage restorations (FCR). The effect of several variables on its reliability was also investigated. METHODOLOGY: Data collected from 825 patients treated in the Advanced Education Program in Endodontics at the University of Iowa, USA were analysed. The experimental group included 425 teeth with FCR, whilst the control group consisted of 400 teeth with natural crowns (NC). The pulp sensibility test results, tooth type, tooth number, type of crown, age, gender, presence or absence of caries and recent use of analgesics were recorded. Bivariate analyses were performed to assess the variables associated with the accuracy of dental pulp sensibility tests for either teeth with crowns or teeth without crowns using chi-square tests, Fisher's exact tests, Cochran-Mantel-Haenszel tests, and the Wilcoxon rank-sum tests. A P-value of less than 0.05 was used as a criterion for statistical significance, and a P-value in 0.05 < P < 0.10 was used as a criterion for marginal relevance. RESULTS: The sensibility test results for FCR teeth had an accuracy of 0.866; sensitivity of 0.835; specificity of 0.879; a positive predictive value of 0.746; and a negative predictive value of 0.926. The data indicated a significant difference in the accuracy of pulp sensibility test results between the experimental and control groups (P < 0.001). Although the cold test in FCR teeth still had high accuracy, teeth with NC were significantly more likely to have true-positive and true-negative results (91.5% NC vs. 86.6% FCR, P = 0.024). No significant differences between FCR and NC were found concerning gender, tooth type, type of crown, the presence of abutment and recent use of analgesic (P > 0.05). CONCLUSION: Pulp sensibility cold testing with 1,1,1,2-tetrafluoroethane (TFE) on teeth with FCR was less accurate than on teeth without full-coverage crowns. However, the use of TFE cold testing is still a relevant and reliable diagnostic tool, particularly for teeth with a pulpal diagnosis of symptomatic irreversible pulpitis. Clinicians should routinely carry out cold pulp sensibility testing on teeth when making a pulpal diagnosis.

Myogenic Disease and Metabolic Acidosis: Consider Multiple Acyl-Coenzyme A Dehydrogenase Deficiency.

BACKGROUND: Multiple acyl-coA dehydrogenase deficiency (MADD) is a rare, inherited, autosomal-recessive disorder leading to the accumulation of acylcarnitine of all chain lengths. Acute decompensation with cardiac, respiratory or hepatic failure and metabolic abnormalities may be life-threatening. CASE PRESENTATION: A 29-year-old woman presented with severe lactic acidosis associated with intense myalgia and muscle weakness. The clinical examination revealed symmetric upper and lower limb motor impairment (rated at 2 or 3 out of 5 on the Medical Research Council scale) and clear amyotrophy. Laboratory tests had revealed severe rhabdomyolysis, with a serum creatine phosphokinase level of 8,700 IU/L and asymptomatic hypoglycemia in the absence of ketosis. Electromyography revealed myotonic bursts in all four limbs. The absence of myositis-specific autoantibodies ruled out a diagnosis of autoimmune myositis. Finally, Acylcarnitine profile and gas chromatography-mass spectrometry analysis of organic acids led to the diagnosis of MADD. A treatment based on the intravenous infusion of glucose solutes, administration of riboflavin, and supplementation with coenzyme Q10 and carnitine was effective. Lipid consumption was strictly prohibited in the early stages of treatment. The clinical and biochemical parameters rapidly improved and we noticed a complete disappearance of the motor deficit, without sequelae. CONCLUSION: A diagnosis of MADD must be considered whenever acute or chronic muscle involvement is associated with metabolic disorders. Acute heart, respiratory or hepatic failure and metabolic abnormalities caused by MADD may be life-threatening, and will require intensive care.

Redesigning the quaternary structure of R67 dihydrofolate reductase. Creation of an active monomer from a tetrameric protein by quadruplication of the gene.

R67 dihydrofolate reductase (DHFR) provides resistance to the antibacterial drug trimethoprim. This R-plasmid-encoded enzyme does not share any homology with chromosomal DHFR. A recent crystal structure of active, homotetrameric R67 DHFR (Narayana, N., Matthews, D. A., Howell, E. E., and Xuong, N.-H. (1995) Nat. Struct. Biol. 2, 1018-1025) indicates that a single active site pore traverses the length of the molecule. Since the center of the pore possesses exact 222 symmetry, site-directed mutagenesis of residues in the pore will produce four mutations/active site. To break this inevitable symmetry, four copies of the gene have been linked in frame to create an active monomer possessing the essential tertiary structure of native tetrameric R67 DHFR. The protein product, quadruple R67 DHFR, is 4 times the molecular mass of native R67 DHFR in SDS-polyacrylamide gel electrophoresis and is monomeric under nondenaturing conditions as measured by sedimentation equilibrium experiments. The catalytic activity of quadruple R67 DHFR is decreased only slightly when compared with native R67 DHFR. Folding of quadruple R67 DHFR is completely reversible at pH 5. However, at pH 8, folding is not fully reversible; this is likely due to a competition between productive intramolecular versus nonproductive intermolecular domain association. The production of a fully active, monomeric R67 DHFR variant will enable the design of more meaningful site-directed mutants where single substitutions per active site pore can be generated.

Clinical commentary: promoting meaning in the lives of cancer survivors.

In clinical settings, nurses look for ways to encourage and to understand their patients' thoughts about the meaning of an illness in their lives. The meaning of illness is appreciated when thoughtful communication that respects the individual's needs and responses. By encouraging patients to describe their thoughts, hopes, and fears about their illness, clinicians will understand what is meaningful in life. Because creating meaning is an individual process, nurses must listen to the patient's personal story and look for the meaning of illness imbedded in it.

Activity distribution of seven digestive enzymes along small intestine in calves during development and weaning.

Ten groups of calves were used to study the changes in activity levels and distribution of seven hydrolases in the intestinal mucosa during development and weaning. The calves in the first group were sacrificed at birth while those in the remaining nine groups were either milk-fed until slaughter on days 2, 7, 28, 56, 70, and 119; or weaned between days 28 and 56 and then slaughtered on days 56, 70, and 119, respectively. The small intestine was immediately cut off and divided into five segments, ie, duodenum, proximal jejunum, median jejunum, distal jejunum, and ileum. In the milk-fed animals, the activity levels of aminopeptidases A and N, alkaline phosphatase, lactase, and isomaltase were maximum at 2 days of age, and then declined sharply between days 2 and 7 but did not change significantly thereafter. By contrast, the maltase activity increased between days 7 and 119, while no sucrase activity was detected. Weaning resulted in a decrease in the activity of lactase and an increase in that of aminopeptidase N, maltase, and isomaltase. The distribution of all these enzymes along the small intestine was slightly influenced by age but not at all by weaning.

Beneficios de la preparación industrial de soluciones dextrosadas e hidroeléctricas para uso neonatal / Benefits of the industrial preparations of dextrose and hydroelectrolytic solutions for use neonatal

Con la hipótesis que el uso de soluciones dextrosadas e hidroeléctricas preparadas mediante técnica industrial no utiliza tiempo de enfermería para su preparación, disminuye la incidencia de contaminación microbiana accidental y aumenta la exactitud de su composición química, llevamos a cabo un trabajo de investigación con los siguientes objetivos: 1) determinar si la composición de las fórmulas propuestas para la PI es apropiada para la hidratación en el período neonatal, 2) comparar dos técnicas de preparación : preparación por enfermería (PE) y preparación industrial (PI). Propusimos 4 fórmulas; N§ 1 y N§ 2 conteniendo dextrosa al 5 por ciento y al 10 por ciento respectivamente y 40 mEq/1 de Na y 20 mEq/1 de K en ambas; N§ 3 dextrosa al 10 por ciento, 20 mEq/1 sin K. Los objetivos se cumplieron en tres etapas. Etapa 1: soluciones PE con enfermeras dedicadas al mismo tiempo al cuidado de recien nacidos en terapia intensiva. Etapa 2: soluciones PI. Etapa 3: soluciones PE con enfermeras dedicadas exclusivamente a la preparación de la solución sin tarea asistencial. Las fórmulas propuestas cubrieron el 80 por ciento de las soluciones indicadas en la unidad de cuidado intensivo neonatal. El tiempo utilizado por enfermería para la preparación de las soluciones PE fue mayor en la etapa 1 que en la 3: X 5,22 minutos vs. 3,98 min. (p<.0005). Se detectó contaminación microbiana en 2/57 (3,5 por ciento) de soluciones PE de la etapa 1 vs 0 por ciento en soluciones PE de etapa 3 y soluciones PI. Se encontraron diferencias significativas en la composición química de Na (p<.01) y K (p<.05) entre las soluciones PE 1§ etapa y PI; en las soluciones PE 3§ etapa persistió una mayor variabilidad con respecto a soluciones PI y una diferencia significativa para el K (p<0.05) pero no se observó diferencias significativas en la composición de Na. En conclusión las soluciones PI presentan mayor exactitud y precisión en su composición química, menor riesgo de contaminación microbiana y no se utiliza tiempo de enfermería para la preparación. Persiste la necesidad de las soluciones PE en 20 por ciento; de los casos; dichas soluciones deberían ser preparadas por enfermeras dedicadas exclusivamente a esta tarea dado que se observó menor variabilidad en la composición química, menor tiempo requerido para su preparación y menor riesgo de contaminación microbiana comparándolas con soluciones preparadas por enfemeras dedicadas a la tarea asistencial.

Beneficios de la preparación industrial de soluciones dextrosadas e hidroeléctricas para uso neonatal / Benefits of the industrial preparations of dextrose and hydroelectrolytic solutions for use neonatal

Con la hipótesis que el uso de soluciones dextrosadas e hidroeléctricas preparadas mediante técnica industrial no utiliza tiempo de enfermería para su preparación, disminuye la incidencia de contaminación microbiana accidental y aumenta la exactitud de su composición química, llevamos a cabo un trabajo de investigación con los siguientes objetivos: 1) determinar si la composición de las fórmulas propuestas para la PI es apropiada para la hidratación en el período neonatal, 2) comparar dos técnicas de preparación : preparación por enfermería (PE) y preparación industrial (PI). Propusimos 4 fórmulas; Nº 1 y Nº 2 conteniendo dextrosa al 5 por ciento y al 10 por ciento respectivamente y 40 mEq/1 de Na y 20 mEq/1 de K en ambas; Nº 3 dextrosa al 10 por ciento, 20 mEq/1 sin K. Los objetivos se cumplieron en tres etapas. Etapa 1: soluciones PE con enfermeras

Effect of insulin administration on contents, secretion, and synthesis of pancreatic lipase and colipase in rats.

After insulin administration in vivo, changes in pancreatic lipase, colipase and amylase contents and outputs were assayed and quantitatively compared. The incorporation of [35S]cysteine into individual enzymes was measured. The mRNA coding for lipase and amylase were determined by dot-blot hybridization. It was found that insulin dose-dependently decreased lipase and colipase contents, but only slightly decreased amylase content. Four hours after insulin administration (0.5 U/100 g), the contents of lipase and colipase decreased 80 and 72%, respectively, while amylase content decreased only about 25%. The decrease in amylase content was accompanied by a 21% increase in its output. The outputs of lipase and colipase only increased transiently and then sharply decreased to a level much lower than control. Total outputs of lipase and colipase could not quantitatively explain the great loss of lipase and colipase contents caused by insulin administration. After insulin injection, the incorporation of [35S]cysteine into amylase increased by 21%, whereas incorporation into lipase and colipase decreased by 18 and 25%, respectively. Dot-blot hybridization with cDNA probes revealed that lipase mRNA decreased by 50% 4 h after insulin administration, whereas mRNA for amylase did not significantly change. The results indicate an inhibitory effect of insulin administration on synthesis of pancreatic lipase and colipase, with the inhibition of lipase synthesis being at pretranslational level.

Cloning and nucleotide sequence of a bovine pancreatic preprocarboxypeptidase A cDNA.

A full-length cDNA clone encoding bovine pancreatic preprocarboxypeptidase A was isolated and sequenced. The 1405-base pair insert contains a 26-nucleotide 5'-noncoding region, a 1260-nucleotide open reading frame and a 76-nucleotide 3'-noncoding fragment plus a poly(A) tail of at least 43 nucleotides. The open reading frame encodes a protein of 419 amino acids, including the 16 amino acid signal peptide. The mature enzyme (309 residues) has two additional C-terminal amino acids, as compared with the amino acid sequence of the protein which was reported more than 20 years ago. In addition, four residues deduced from the nucleotide sequence differed from those identified in the reported amino acid sequence from their net charge: Asp-89, Asp-114, Gln-122, and Asp-185 instead of Asn-89, Asn-114, Glu-122, and Asn-185, respectively. A high degree of identity exists between the nucleotide sequences (81.3%), on the one hand, and the amino acid sequences (78.3%), on the other hand, of bovine preprocarboxypeptidase A and rat preprocarboxypeptidase A1.

Autolysis of proproteinase E in bovine procarboxypeptidase A ternary complex gives rise to subunit III.

Extracts of bovine pancreatic tissue are shown by HPLC to contain two distinct ternary complexes of procarboxypeptidase A (subunit I), chymotrypsinogen C (subunit II) and either proproteinase E or subunit III. It is shown that proproteinase E in the complex generates subunit III by removal of 13 N-terminal residues when the former is allowed to autolyze in solution or when catalytic amounts of isolated active proteinase E are added to it. Autolysis of proproteinase E was accompanied by the loss of potential activity towards specific synthetic substrates and occurred at a higher rate in pancreatic juice than in pancreatic tissue extracts, even when both were processed in the presence of serine protease inhibitors. We conclude that subunit III (also called truncated protease E) is an autolytic product of proproteinase E and not an ab initio component of the native ternary complex.

Insect immunity. Characterization of a Drosophila cDNA encoding a novel member of the diptericin family of immune peptides.

Drosophila shows an immune response when challenged by injection of low doses of bacteria. To date, the molecules involved in this immune reaction have remained elusive, with the exception of cecropins (4-kDa antibacterial peptides initially isolated from the moth Hyalophora cecropia) for which three closely related genes have been characterized recently. We report the molecular cloning and sequencing of a cDNA from a library of immune Drosophila which encodes a novel member of the family of diptericins (9-kDa antibacterial peptides initially isolated from the fly Phormia terranovae). Transcripts for the Drosophila diptericin are detected 2 h after injection of bacteria. They are apparently derived from a single gene mapping at position 56 A on the right arm of the second chromosome. We discuss the existence of a distant relationship between the diptericins and two other groups of anti-bacterial insect proteins, the attacins, and the sarcotoxins II.

Isolation and nucleotide sequence of cDNA clone for bovine pancreatic anionic trypsinogen. Structural identity within the trypsin family.

A cDNA clone encoding an anionic form of bovine trypsinogen was isolated from a pancreatic cDNA library. The corresponding 855-nucleotide mRNA contains a short 5' noncoding region of 8 nucleotides and a long 3' noncoding region of 56 nucleotides in addition to a poly(A) tail of at least 50 nucleotides. The deduced amino acid sequence for the anionic pretrypsinogen (247 residues) includes the N-terminal 15-amino-acid signal peptide followed by an 8-amino-acid activation peptide. The zymogen (232 residues) contains an additional C-terminal serine, compared with the amino acid sequence of bovine cationic trypsinogen. The identity between the anionic and cationic forms of bovine trypsinogen (65%) is lower than that existing between the anionic protein and other mammalian anionic trypsinogens (73-85%), suggesting that trypsin gene duplication in mammals occurred prior to the evolutionary events responsible for the species divergence. Bovine pancreatic anionic trypsin possesses all the key amino acids characteristic of the serine protease family.

Regulation by a protein-free carbohydrate-rich diet of rat pancreatic mRNAs encoding trypsin and elastase isoenzymes.

The levels of mRNAs coding for trypsin and elastase isoenzymic forms were determined in the pancreatic tissue of rats fed a high-carbohydrate protein-free diet for a 0-5-day period. No change in the amounts of mRNAs coding for the two isoelastases was observed, although previous results showed that the biosynthesis of anionic elastase was markedly increased, whereas the biosynthesis of cationic elastase decreased, suggesting the existence of a translational-control mechanism in response to nutritional substrates. In contrast, the levels of mRNAs specific for the three isotrypsins were significantly enhanced, possibly as a result of transcriptional regulation and/or a change in messenger stability. In combination with earlier observations of an overall decrease in cationic trypsin biosynthesis during the same nutritional manipulation, these results suggest that formation of this enzyme is also subject to translational control.

Understanding the cancer patient's search for meaning.

The period following a cancer diagnosis has been described as a time when concerns about life and death predominate. However, little is understood about how persons recently diagnosed with cancer deal with such issues as finding meaning in their lives, their illness, and their impending death. The purpose of this study is to describe what is involved in the process of the personal search for meaning conducted by the patient who has been recently diagnosed with breast, lung, or colorectal cancer. Six major themes were identified from interviews of 30 patients: seeking an understanding of the personal significance of the diagnosis; looking at the consequences of the cancer diagnosis; reviewing life; change in outlook toward self, life, others; living with the cancer; and hope. Two significant factors were found--faith and social support. With an understanding of the components in an individual's search for meaning of life, the nurse can facilitate the process by which patients explore what the cancer means for their lives.

Specific regulation of the gene expression of some pancreatic enzymes during postnatal development and weaning in the calf.

The construction of cDNA library from calf pancreas allowed us to examine the mRNA levels of four pancreatic hydrolases (chymotrypsin, lipase, trypsin and amylase) during postnatal development in preruminant and ruminant animals. The lack of parallel variations in the levels of the enzyme specific activities suggested that protein synthesis was not coordinately regulated. In preruminant calves, the change in chymotrypsin and lipase mRNA concentrations (0-28 day period) and in trypsin mRNA concentrations (0-119 day period) was opposite to that in the corresponding specific activities. In contrast, both the activity and mRNA profiles of amylase during the latter period, on the one hand, and those of chymotrypsin and lipase during the 28-119 day period, on the other hand, were comparable. However, the extent to which the specific activity and mRNA concentration of each enzyme were increased did not necessarily coincide. The observed changes in mRNA levels probably resulted from some transcriptional control of the gene expression and/or variation in mRNA stability. Moreover, a translational regulation of the messengers could explain the existence of non-parallel mRNA and specific activity profiles. In sharp contrast with the multiple control of protein synthesis during postnatal development in preruminant calves, weaning was found to induce the same increase in enzyme activity and corresponding mRNA for each of the four pancreatic enzymes, suggesting that pretranslational modulation of gene expression was mainly, if not exclusively, concerned.

Rat pancreatic colipase mRNA: nucleotide sequence of a cDNA clone and nutritional regulation by a lipidic diet.

A cDNA clone encoding rat pancreatic colipase was isolated using as a probe a synthetic deoxyoligonucleotide corresponding to a highly conserved amino acid sequence region in colipases from other species. The cloned messenger codes for a protein of 95 amino acids plus a signal peptide of 17 amino acids. The structure of the full-length cDNA was also determined and the corresponding amino acid sequence showed a high degree of homology with those of other known colipases. Quantification of the homologous mRNA in the pancreas of animals fed a high-lipid diet was consistent with a specific though moderate induction of colipase messenger by the nutritional manipulation.