Volvulus of the transverse colon in children--Report of a case and review of the literature

Sigmoid, cecal and transverse colon volvulus have been responsible for approximately 3% of all large bowel obstruction in the United States. Transverse colon volvulus is much less frequent, occurring in less than 4% of all reported cases of colonic torsion. In the pediatric age group a review of the literature revealed seven cases only, to which we are able to add an eighth. Predisposing abnormalities implicated in the etiology of volvulus of the transverse colon include a redundant transverse colon, an elongated mesentery and close attachment or lack of fixation of the proximal and distal transverse colon. Chronic constipation and mental retardation are associated with this condition. The treatment is surgical intervention to untwist the volvulus and resect the redundant and often nonviable colon with primary colocolostomy or end-colostomy and mucous fistula as indicated.

Free energy coupling in the interactions between Ca2+, calmodulin, and phosphorylase kinase

Interactions between Ca2+, exogenous calmodulin, and white skeletal muscle phosphorylase kinase have been quantitatively studied by equilibrium gel filtrations and analyzed by means of the so-called "linked functions" theory (Weber, G. (1975) Adv. Protein Chem. 29, 1-83). Four moles of calmodulin, each saturated with at least 3 Ca2+ ions, bind to 1 mol of phosphorylase kinase with a Kdiss of 2.3 nM. The activation of the enzyme as a function of free [Ca2+] shows that the intrinsic Ca-binding properties of phosphorylase kinase do not change upon binding of exogenous calmodulin, and confirms that alpha beta gamma delta X Ca3 is the functional catalytic unit through which activation occurs. Direct binding studies reveal that the intrinsic Ca-binding properties of the enzyme remain the same in the presence of either 0.5 or 8 mM Mg2+, indicating that phosphorylase kinase is endowed with Ca-specific sites. Upon interaction with the enzyme, calmodulin acquires strong positive cooperativity in Ca2+-binding: whereas its first two stoichiometric Ca-binding constants are not significantly different from those of free calmodulin, the third Ca2+ ion binds with an affinity at least 10(5)-fold higher than the corresponding one in free calmodulin. Calmodulin liganded with 1 or 2 Ca2+ displays the same low affinity for the enzyme as calmodulin depleted of Ca2+ (approximate Kdiss = 10(-4)-10(-3) M). The alpha beta gamma delta X calmodulin X Ca3 complex is strengthened by a free energy coupling of -8 kcal/mol upon complexation. The quantitative analysis of our results predicts that in spite of this high free energy barrier the dissociation of the complex (i.e. the inactivation of phosphorylase kinase) occurs rapidly upon lowering free [Ca2+].

Structural changes in melittin and calmodulin upon complex formation and their modulation by calcium

In the presence of Ca2+, calmodulin forms a 1:1 high-affinity complex (Kd = 3 nM) with melittin, a peptide from bee venom; in the presence of ethylenediaminetetraacetic acid, a second type of complex, of much lower affinity, is formed [Comte, M., Maulet, Y., & Cox, J. A. (1983) Biochem. J. 209, 269-272]. In this paper, these interactions were studied by tryptophan fluorescence and circular dichroism spectroscopy in near- and far-UV. Interaction between the two peptides in the presence as well as in the absence of Ca2+ leads to the shielding of the tryptophan residue of melittin from its aqueous environment and to an increase in the alpha-helical content of bound melittin; for instance the Ca2+-dependent high-affinity complex formation enhances the alpha-helical content of melittin from 5 to 72%. Provided Ca2+ is present, the interaction between the two peptides leads to significant changes in the environment of at least one tyrosine residue of calmodulin as measured by near-UV circular dichroism. In the absence of Ca2+, calmodulin binds two melittin molecules with a Kd of ca. 10 microM; at higher concentrations of free melittin, additional binding occurs (up to 5 mol of melittin/mol of calmodulin), with concomitant denaturation of calmodulin. In the presence of 4.0 M urea, the low-affinity complexes formed in the absence of Ca2+ dissociate, due to the denaturation of metal-free calmodulin, whereas the spectroscopic signals of the high-affinity Ca2+-dependent complex are not affected.(ABSTRACT TRUNCATED AT 250 WORDS)

Ca2+-dependent high-affinity complex formation between calmodulin and melittin

The amphiphatic polypeptide melittin migrates as an equimolar complex with bovine brain calmodulin when monitored by gel disc electrophoresis or gel filtration in the presence of Ca2+, even in 4M-urea. The complex disassociates in the presence of EDTA and urea. The affinity is of the same order as that of calmodulin for its target enzymes, and more than 1000-fold higher than that of calmodulin for basic peptide hormones or hydrophobic drugs. The activation of brain phosphodiesterase by calmodulin is inhibited by melittin. The kinetics of inhibition suggest competition between the enzyme and melittin for calmodulin. The calmodulin-melittin interaction may constitute a model for that existing between calmodulin and its target enzymes.

Calmodulin from neurospora crassa. General properties and conformational changes

Calmodulin from Neurospora crassa has been purified to electrophoretic homogeneity. Equilibrium gel filtration experiments suggest that its Ca-binding properties are indistinguishable from those of vertebrate calmodulins. The isoelectric point of 4.04 and electrophoretic behavior under nondenaturing conditions indicate that N. crassa calmodulin is slightly less acidic than its vertebrate counterpart. The amino acid composition is typical of plant calmodulins with the exception that trimethyllysine is absent and that the content of Ser is unusually high. The tryptic peptide map of N. crassa calmodulin reveals an important number of point mutations as compared to vertebrate calmodulin. Differences in primary structure may explain why N. crassa calmodulin is less potent in the activation of myosin light chain kinase than calmodulins from higher organisms. The far UV circular dichroic spectra of the Ca-, Mg-, and metal-free forms of N. crassa calmodulin are similar to those of vertebrate calmodulin; in contrast, the near UV circular dichroic spectra are very different, apparently due to the differences in Tyr content. The single Tyr residue of N. crassa calmodulin, presumably located in position 138, undergoes an inversion of optical chirality upon addition of Ca2+, but not of Mg2+, to the metal-free protein.

Activation of human erythrocyte Ca2+-dependent Mg2+-activated ATPase by calmodulin and calcium: quantitative analysis

The effect of Ca2+ and calmodulin on (CaM) on the activation of Ca2+-dependent Mg2+-activated ATPase (Ca2+,Mg2+-ATPase; ATP phosphohydrolase, EC 3.6.1.3) has been carried out because of the finding that the CaM dependence of the activation varies with the concentration of free Ca2+, similarly to brain phosphodiesterase and adenylate cyclase. The study was carried out in the absence of chelating agents because they strongly interfere in the enzyme kinetics. Three main conclusions can be drawn (i) CaM-Ca3 and CaM-Ca4 together are the biochemically active species in vitro. (ii) These species bind in a non-cooperative way to the CaM-binding site of the enzyme with a dissociation constant of 6 x 10(-10) M or 1.1 x 10(-8) M, depending on whether Ca2+ saturates the substrate binding site of the enzyme or not. (iii) The binding of CaM-Ca3 to the enzyme lowers the dissociation constant of the enzyme for Ca2+ at the substrate binding site from 51.5 to 2.8 microM. Contrary to general belief, CaM does not induce pronounced positive cooperativity in the binding of Ca2+ to the enzyme. Such a cooperativity is seen only when the enzyme is incompletely saturated with the activator, but it disappears in the presence of saturating concentrations of CaM-Ca3. The rate equation proposed here accurately predicts the extent of enzyme activation over a wide range of Ca2+ and CaM concentration. In healthy erythrocytes the concentrations of Ca2+ and CaM are such that the Ca pump works with a minimal dissipation of energy, but a small increase in the intracellular Ca2+ concentration leads to a strong amplification of the pumping activity.

Changing treatment of pediatric splenic trauma

A review of splenic injuries at Cincinnati Children's Hospital Medical Center from July 1978 to June 1980 revealed this form of injury in 29 patients. Treatment without surgery was successful in 21 patients. Seven patients required operation. One patient died shortly after admission of severe associated injuries. All patients admitted with blunt abdominal trauma were initially treated conservatively. If the clinical state improved, after transfusions if necessary, or remained stable and there were no objective signs of further blood loss, conservative therapy was continued. Liver-spleen scans were obtained on an urgent basis to confirm the diagnosis of splenic injury in patients who did not undergo surgery. No complications of treatment without surgery were recognized. The satisfactory outcome in these patients suggests that there is a place for treatment without surgery in some children with splenic injury.

Tracheal agenesis: a clinical approach

Tracheal agenesis, though seemingly rare and fatal to date, has been reported from multiple institutions with increasing frequency. Establishment of the diagnosis necessitates a high index of suspicion in an infant in respiratory distress at birth, without a cry and in whom intubation is difficult. Following definitive diagnosis by endoscopy, infants have been given a chance at survival on four occasions by prompt surgical intervention. The procedure proposed by Altman is adequate for initial stabilization. Postoperative management is aided by the use of continuous positive airway pressure (CPAP) and rigorous pulmonary toilet. Definitive correction should be considered at an early stage in order to prevent fatal complications.

Ca2+-dependent regulation of calmodulin binding and adenylate cyclase activation in bovine cerebellar membranes

The binding parameters of 125I-labeled calmodulin to bovine cerebellar membranes have been determined and correlated with the activation of adenylate cyclase by calmodulin. In the presence of saturating levels of free Ca2+ calmodulin binds to a finite number of specific membrane sites with a dissociation constant (Kd) of 1.2 nM. Furthermore, Scatchard analysis reveals a second population of binding sites with a 100-fold lower affinity for calmodulin. The Ca2+-dependence of calmodulin binding and of adenylate cyclase activation varies with the amount of calmodulin present, as can be inferred from the model of sequential equilibrium reactions which describes the activation of calmodulin-dependent enzymes. On the basis of this model, a quantitative analysis of the effect of free Ca2+ and of free calmodulin concentration on both binding and activation of adenylate cyclase was carried out. This analysis shows that both processes take place only when calmodulin is complexed with at least three Ca2+ atoms. The concentration of the active calmodulin X Ca2+ species required for half-maximal activation of adenylate cyclase is very similar to the Kd of the high affinity binding sites on brain membranes. A Hill coefficient of approx. 1 was found for both processes indicating an absence of cooperativity. Phenothiazines and thioxanthenes antipsychotic agents inhibit calmodulin binding to membranes and calmodulin-dependent activation of adenylate cyclase with a similar order of potency. These results suggest that the Ca2+-dependent binding of calmodulin to specific high affinity sites on brain membranes regulates the activation of adenylate cyclase by calmodulin.

Sarcoplasmic calcium-binding proteins in insect muscle. Isolation and properties of locust calmodulin

No sarcoplasmic calcium-binding proteins reminiscent of those-described in other arthropods could be detected in locust flight and leg muscle. Instead, these tissue are rich in calmodulin. The purification and functional properties of this protein, which was purified to electrophoretic homogeneity, are very similar to those of calmodulin from bovine brain.

Regulation of brain cyclic nucleotide phosphodiesterase by calmodulin. A quantitative analysis

Comparison of the parameters of Ca and Sr binding to bovine brain calmodulin with the activation of bovine brain phosphodiesterase by Ca2+ and Sr2+ at different calmodulin concentrations allows a quantitative description of the mechanism of activation of the enzyme. Equilibrium dialysis studies show that calmodulin possesses three high affinity (K'diss = 6 micoM) and one low affinity (K'diss = 200 microM) sites for Ca2+. All four sites display the same affinity for Sr2+ with K'diss = 180 microM. In the presence of calmodulin, soluble bovine brain phosphodiesterase is activated by Sr2+ to the same extent as by Ca2+. The activation of the enzyme shows the same Ca2+/Sr2+ selectivity ratio of 30 as the binding of the metal ions to calmodulin. Based on the findings that the Ca2+ or Sr2+ concentration at half-maximal activation of the enzyme depends on the concentration of calmodulin present, a quantitative analysis of activation was carried out as a function of the four calmodulin-metal complex species (CaM . Men). The data show that the activating species are CaM . Ca3, CaM . Ca4 or CaM . Sr3, CaM . Sr4. The interaction of these activating species with phosphodiesterase follows the Hill equation with a dissociation constant of 10(-9) M and a Hill coefficient of 2, irrespective of the binding characteristics of Ca2+ or Sr2+. The latter value agrees well with the fact that phosphodiesterase possesses two binding sites for calmodulin.

Calmodulin-free skeletal-muscle troponin C prepared in the absence of urea

A method is described for the rapid preparation of electrophoretically pure troponin C from rabbit skeletal-muscle myofibrils that avoids the use of urea. The three-step procedure includes extraction od the myofibrils with EDTA-containing buffers, one-step elution from DEAE-Sephadex and Sephadex G-100 chromatography in the presence of EDTA. The procedure gives yields comparable with those of currently used methods that involve dissociation of the troponin complex with urea. Except for the thiol-group reactivity, troponin C produced by our method is physicochemically and functionally indistinguishable from that obtained by the classical procedure. Purified troponin C always contains traces of calmodulin. However, this contamination can be decreased to less than 0.02% by means of a second Sephadex G-100 chromatography step in the presence of EDTA.

Abdominoscrotal hydrocele--cause of abdominal mass in children

Abdominoscrotal hydrocele is relatively uncommon in adults and rare in children. The case presented typifies the classic features of the clinical presentation and the satisfactory response to conservative surgical therapy.

A thermodynamic analysis of the binding of calcium and magnesium ions to parvalbumin

Microcalorimetry and equilibrium dialysis were used to determine the thermodynamic functions delta H0, delta G0 and delta S0 guiding the interaction of Ca2+ and Mg2+ with purified carp muscle isoparvalbumin of pI 4.25. The equilibrium dialysis studies indicate equal affinities of the two metal sites of parvalbumin for either Ca2+ or Mg2+ with equilibrium constants of KCa = 2.7 X 10(9) M-1, and KMg = 9.5 X 10(4) M-1. Binding of the two metal ions is fully competitive with no indication for cooperative effects. The apparent Ca2+ affinity constant K'Ca in the presence of 1 mM Mg2+ is 2.8 X 10(7) M-1, and the Mg2+-Ca2+ exchange equilibrium constant equals 2.8 X 10(4) M-1. Microcalorimetry shows that parvalbumin exhibits negative reaction enthalpies of -37.2 kJ/mol metal site for Ca2+ binding and -25.1 kJ/mol site for Mg2+-Ca2+ exchange, yielding delta H0 = -12.1 kJ/mol site for Mg2+ complex formation. Enthalpy changes are linearly dependent upon the amount of metal bound to the protein, thus corroborating the equal affinities of the two sites. Reaction entropies delta S0 are +55.2 J x mol-1 x K-1 for Ca2+ complex formation and +54.8 x mol-1 x K-1 for Mg2+ complex formation. Thus the respective metal binding processes are driven by both enthalpy and entropy conbinations, and are reminiscent of Ca2+ binding to troponin C. The reaction entropy observed during Mg2+-Ca2+ exchange (0.4 J x mol-1 x k-1) is negligible in spite of the markedly different hydration entropies for Ca2+ and Mg2+. This indicates that the two metal complexes of parvalbumin do not have the same conformation entropy. Since no variation in the intrinsic protein fluorescence was observed upon metal exchange, the conformation differences must be restricted to the immediate environment of the metal binding sites.

Evidence for hemocyanin formation in the compound eye of Squilla mantis (Crustacea, Stomatopoda)

In the retina and in the subretinal space of the compound eye of Squilla mantis a special kind of pigment cell is present. The crystalline inclusions of this cell have been identified as hemocyanin, as determined (i) by the dimensional congruence of the crystalline substructure with the dimensions of isolated, purified hemocyanin, and (ii) by the immunofluorescence reaction using anti-hemicyanin antibodies. The ultrastructure of these cells, their location and the presence of crystalline bodies in their cytoplasm suggest that they are sites of hemocyanin synthesis and homologous to the cyanocytes or cyanoblasts of Limulus.

Retroperitoneal lymph node dissection for Wilms' tumor

Nephrectomy for Wilms' tumor was performed on 58 patients over a 20-yr period, and retroperitoneal lymphadenectomy was performed on 35 who presented with no demonstrable metastases. The survival rate was 100% for 19 clinical group I patients with negative nodes. Positive nodes in 9 instances led to 5 long-term survivors and significantly influenced staging as a guide for further therapy.

Renal homotransplantation in children

Ninety-six renal transplants in 77 pediatric patients are reported with follow-up as long as 12 1/2 years. Thirteen of the first 14 patients are living with a functioning kidney after eight to 12 1/2 years. The patient survival for the entire group is 78%. Sixty-four percent are living with a functioning transplanted kidney. Splenectomy was initially performed at the time of transplant but has been discontinued because of concern that splenectomy in the immunosuppressed patient was related to an increased occurrence of septic complications. Anencephalic newborn infants have been found to be a satisfactory source of cadaver donor kidneys. Growth and development have been satisfactory when the transplant is performed prior to 12 years of age, if it functions well, and if an alternate-day regimen of steroid administration is followed. Both boys and girls have now passed through puberty with their transplanted kidneys, have married, become parents, and are leading essentially normal lives. A plea is made for earlier transplantation in small children with irreversible progressive renal failure before they develop severe stunting of growth and before the need for prolonged dialysis.

Calcium, magnesium and the conformation of parvalbumin during muscular activity

The conformation of perch parvalbumin in the Ca-, Mg- and metal-free state was studied by intrinsic fluorescence, trypsin susceptibility, thiol titration and circular dichroism. The data reveal that Ca-parvalbumin has a more compact structure than the metal-free protein, with a high alpha-helical content and a buried thiol. No difference in conformation could be detected between Mg- and Ca-parvalvumin, indicating that the Ca-Mg exchange that may take place during muscular activity is accompanied by little or no structural changes. Furthermore, recently published kinetic parameters can now be interpreted as meaning that, during the contraction-relaxation cycle, parvalbumin often stays in the Mg-form instead of switching to the Ca-form which is predominant in vitro.

Leukemic infiltration of the testis during long-term remission

Of 33 boys with acute lymphocytic leukemia treated at the Cincinnati Children's Hospital during 1971--1974, 14 remained in clinical and bone marrow remission for periods longer than 2.5 yr. Of these 14 patients, 8 then developed testicular leukemia. In 7 of these 8 patients, testicular infiltration was the first or only evidence of relapse. In 2 of the patients the gonads were not grossly abnormal, and testicular relapse was discovered as a result of routine wedge biopsy before therapy was to have been stopped. This experience has led to our policy of routine testicular biopsy in boys with acute lymphocytic leukemia who have had continuous remission for 3 yr and who are otherwise candidates for discontinuance of maintenance therapy.

Transplantation of cadaver kidneys from anencephalic donors

Of 14 potential anencephalic donors, the kidneys of six were transplanted to recipients ranging in age from 4 to 19 years and in weight from 8 to 49 kg. In three recipients, serum creatinine levels are less than 1.0 mg/dl 1.5 to 9.5 years after transplant. The transplants failed in two for technical reasons; in one, the kidneys were lost by rejection. The other anencephalic infants were not suitable as donors because of rapid deterioration of vital signs (4), ABO incompatibility (3), and inability to perfuse the kidney (1). Successfully transplanted kidneys from this source rapidly increase in size and function to accomodate even large recipients.

Sarcoplasmic calcium-binding proteins in protochordate and cyclostome muscle: characterization of a new protein from amphioxus

A sarcoplasmic calcium-binding protein (SCP) has been purified from the muscle of the protochordate Amphioxus and shown to be more similar to invertebrate SCP's than to their counterpart found in vertebrates, i.e. parvalbumins. The Amphioxus protein has a pI of 4.9, is rich in tyrosine and tryptophan, has a molecular weight of 22,000 and binds strongly 2Ca2+ with a pK of 7.88. Magnesium competes with calcium for only one of the two metal-binding sites and induces positive cooperativity in Ca2+ binding. In cyclostome muscle (lamprey and hagfish), no protein with high affinity for Ca2+ or Mg2+ could be found, irrespective of molecular weight. Instead, a protein with moderate affinity for Ca2+ (less than or equal to 10(5) M(-1)) was detected: it has a molecular weight of 60,000 and might be quite ubiquitous, as the presence of a similar protein has been reported both in red and white muscle of vertebrates such as chicken and rabbit.

Intussusception in the 1970s: indications for operation

Eighty-one patients with proven intussusception were treated at the Cincinnati Children's Hospital from 1970-1974. One died. Seven of these had ileo-ileal intussusception, all treated surgically. Seventy-four had colonic components of their intussusceptions. In 58 of these patients (78%), reduction was attempted at barium enema, successfully in 32. Hydrostatic reduction was abandoned and the patient operated upon when the intussusception was not pushed out of the colon, when barium failed to reflux into several loops of ileum, or when there was a large persistent filling defect in the cecum or terminal ileum. Primary operation without barium enema was done in 16 patients. The appearance of intestinal obstruction by abdominal x-ray seemed to give the best warning about the complicated, incarcerated, or gangrenous intussusception. Primary operation is, therefore, advised for the patient with intussusception if there is x-ray evidence of intestinal obstruction. The age of the patient and the duration of his symptoms do not seem important in this regard, except as they correlate with peritonitis or obstruction. For the patient without peritonitis or intestinal obstruction, attempted reduction of the intussusception at barium enema seems safe and effective, regardless of the patient's age or duration of his symptoms.

Cellular distribution of sarcoplasmic calcium-binding proteins by immunofluorescence

Specific antibodies against carp paravalbumin, crayfish calcium binding protein and crayfish arginine kinase were used for indirect immunofluorescence localization of the respective proteins. Simultaneous staining of the same muscle sections with human serum containing anti-actin autoantibodies served as a probe to identify the isotropic band. Parvalbumin appears to be evenly distributed in carp white muscle. The crayfish calcium binding protein however shows a distinct localization, in the isotropic band, coincident with the actin staining. Arginine kinase, which has the same molecular weight and is extractible in the same way as the calcium binding protein does not show this distinct localization, but is evenly present in crayfish tail muscle, similarly to parvalbumin. The possible meaning of the different distribution of the two calcium binding proteins is discussed.

Isolation and properties of a sarcoplasmic calcium-binding protein from crayfish

The sarcoplasmic calcium-binding protein from crayfish muscle has been purified to homogeneity. The protein has a molecular weight of 44000, as determined by sedimentation equilibrium and Sephadex chromatography. It dissociates in the presence of sodium dodecyl sulfate, 8 M urea, or, after succinylation, into two subunits of 22000 molecular weight. The protein is free of carbohydrate and phosphorus but contains 4 g-atoms of calcium/44000 at a free calcium concentration of 0.1 muM. Approximately 45% of the polypeptide backbone appears to be alpha-helical. The amino acid composition reveals a high proportion of alanine and acidic amino acids, a normal content of aromatic amino acids, and the absence of histidine. The isoelectric point, as determined by isoelectric focusing, is 5.1. The protein contains a free threonyl NH2 terminal. Two thiols react rapidly in the native protein, six in the calcium-free form. Immunochemically, there is no difference between the protein from tail, claw, and heart muscle. In these three crayfish tissues, the concentrations of calcium-binding protein, as determined by rocket immunoelectrophoresis, are markedly different: 2.73 g/kg in tail, 0.72 in claw, and 0.073 in heart muscle. A functional analogy with the parvalbumins of vertebrates can be postulated.

A common factor in the MMPI scales of married couples

Using canonical analysis, a common factor in the MMPI scales of husbands and wives was found. The Sc, Pd, and Hs scales for both the husbands and the wives contributed heavily to the relationship. Other scales contributing to the correlation between the personality components of the pairs were F, Hy Pt, and Si for the husbands and Pa for the wives. The results were interpreted as indicating areas of homogeneity and heterogeneity in the personalities of married couples.