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J J Hill

Publications and source records attributed to J J Hill.

At least 19 recordsLinked to original sources
PubMed2001

Biophysical characterization of recombinant human Bcl-2 and its interactions with an inhibitory ligand, antimycin A.

Apoptosis is an essential physiological process, regulated by the family of Bcl-2-related proteins. However, the molecular mechanism by which Bcl-2 regulates apoptosis still remains elusive. Here we report the functional studies of recombinant human Bcl-2 with the deletion of 22 residues at the C-terminal membrane-anchoring region (rhBcl-2Delta22). Characterization of rhBcl-2Delta22 showed that the recombinant protein is homogeneous and monodisperse in nondenaturing solutions, stable at room temperature in the presence of a metal chelator, and an alpha-helical protein with unfolding of secondary structure at a T(m) of 62.8 degrees C. Optimal membrane pore formation by rhBcl-2Delta22 required negatively charged phospholipids. The existence of a hydrophobic groove in rhBcl-2Delta22 was demonstrated by the fluorescence enhancement of the hydrophobic ANS probe with which a pro-apoptotic Bak BH3 peptide competed. The respiratory inhibitor antimycin A also bound to the hydrophobic groove of rhBcl-2Delta22 with a K(d) of 0.82 microM. The optimal binding conformation of antimycin A was predicted from molecular docking of antimycin A with the hBcl-2 model created by homology modeling. Antimycin A selectively induces apoptosis in cells overexpressing Bcl-2, suggesting that hydrophobic groove-binding compounds may act as selective apoptotic triggers in tumor cells.

Amino Acid Sequence↗
PubMed2000

Inhibition of a Gi-activated potassium channel (GIRK1/4) by the Gq-coupled m1 muscarinic acetylcholine receptor.

The G protein-coupled inwardly rectifying K+ channel, GIRK1/GIRK4, can be activated by receptors coupled to the Galpha(i) subunit. An opposing role for Galpha(q) receptor signaling in GIRK regulation has only recently begun to be established. We have studied the effects of m1 muscarinic acetylcholine receptor (mAChR) stimulation, which is known to mobilize calcium and activate protein kinase C (PKC) by a Galpha(q)-dependent mechanism, on whole cell GIRK1/4 currents in Xenopus oocytes. We found that stimulation of the m1 mAChR suppresses both basal and dopamine 2 receptor-activated GIRK 1/4 currents. Overexpression of Gbetagamma subunits attenuates this effect, suggesting that increased binding of Gbetagamma to the GIRK channel can effectively compete with the G(q)-mediated inhibitory signal. This G(q) signal requires the use of second messenger molecules; pharmacology implicates a role for PKC and Ca2+ responses as m1 mAChR-mediated inhibition of GIRK channels is mimicked by PMA and Ca2+ ionophore. We have analyzed a series of mutant and chimeric channels suggesting that the GIRK4 subunit is capable of responding to G(q) signals and that the resulting current inhibition does not occur via phosphorylation of a canonical PKC site on the channel itself.

Calcium Signaling↗
PubMed2000

Examining the psychological consequences of surviving childhood cancer: systematic review as a research method in pediatric psychology.

OBJECTIVE: To report the results of a systematic review to determine the psychological consequences of surviving childhood cancer. METHODS: Searches were conducted using Psyclit, Medline, Cinahl, and Bids and articles selected on the basis of predefined criteria. Key information was extracted to data sheets and these were rated by two coders. RESULTS: Twenty studies were identified, seventeen from the United States. Survivors did not show deficits in measures of anxiety, depression, or self-esteem when compared with population norms or matched controls. Survivors of some cancers (bone tumors) have poorer outcomes. CONCLUSIONS: The results of this review support findings of previous descriptive reviews. Methodological problems include poorly reported medical information (for example, time since diagnosis), heterogeneous samples, self-selection of participants, poorly chosen/lack of suitable measures, and a lack of longitudinal work. Findings are discussed in terms of the need for cross-cultural work on adjustment to childhood cancer, the need for studies to take on a more developmental approach, and for greater national and international collaboration.

Adaptation, Psychological↗
PubMed1999

Bacterial expression and characterization of the ligand-binding domain of the vitamin D receptor.

The ligand-binding domain of the rat vitamin D receptor (amino acids 115-423) was expressed as an amino-terminal His-tagged protein in a bacterial expression system and purified over Ni-nitrilotriacetic acid resin and a Mono S column. The purified protein bound its ligand, 1,25-dihydroxyvitamin D3, with high affinity, similar to that of the full-length protein. Saturation of the protein with ligand quenched 90% of the tryptophan fluorescence, consistent with the purified protein being uniformly able to bind ligand. Addition of ligand produced no change in the tryptophan fluorescence lifetime, suggesting static quenching as the mechanism of fluorescence decrease. The near-UV circular dichroism spectrum showed a large increase in signal following the addition of ligand, consistent with a change in the environment of aromatic amino acid side chains. The far-UV circular dichroism spectrum was consistent with a protein of high alpha-helical content. Sedimentation equilibrium experiments demonstrated that the protein formed higher-order complexes, and the distribution of the protein among these complexes was significantly shifted by addition of ligand.

Animals↗
PubMed1999

MosquI, a novel family of mosquito retrotransposons distantly related to the Drosophila I factors, may consist of elements of more than one origin.

A novel family of non-long-terminal-repeat (non-LTR) retrotransposons, named MosquI, was discovered in the yellow fever mosquito, Aedes aegypti. There were approximately 14 copies of MosquI in the A. aegypti genome. Four of the five analyzed MosquI elements were truncated at the 5' ends while one of them, MosquI-Aa2, was full-length. All five MosquI elements ended with 4-10 TAA tandem repeats, as the Drosophila I factors do. Interestingly, MosquI elements were often found near genes and other repetitive elements. The 6,623-bp MosquI-Aa2 contained two open reading frames (ORFs) flanked by a 404-bp 5' untranslated region and a 326-bp 3' untranslated region. The two ORFs code for nucleocapsids, endonuclease, reverse transcriptase, and RNase H domains. Although overall structural and sequence comparisons suggest that MosquI is highly similar to the Drosophila I factors, phylogenetic analysis based on the reverse transcriptase domains of 40 non-LTR retrotransposons indicate that MosquI and I factors are likely paralogous elements which may have been separated before the split between the ancestors of mollusca and arthropoda. Pairwise comparisons between the four truncated MosquI elements showed 96.7%-99.5% identity at the nucleotide level, while comparisons between the full-length MosquI-Aa2 and the truncated copies showed only 80.2%-81.8% identity. These comparisons and preliminary phylogenetic analyses suggest that the full-length and truncated MosquI elements may belong to two subfamilies originating from two source genes that diverged a long time ago. In contrast to the defective I factors in Drosophila melanogaster, which are likely very old components of the genome, the truncated MosquI elements seem to have been recently active. Finally, the genomic distribution and evolution of MosquI elements are analyzed in the context of other non-LTR retrotransposons in A. aegypti.

Aedes↗
PubMed1997

Equilibrium binding of estrogen receptor with DNA using fluorescence anisotropy.

Interaction of estrogen receptor (ER) with DNA sequences known as estrogen response elements (ERE) is required for estrogen regulation of the expression of target genes. To characterize the affinity and specificity of ER interaction with ERE sequences in vitro under equilibrium conditions, fluorescence anisotropy assays were performed using recombinant, purified ER and a fluorescein-labeled 35-base pair oligonucleotide bearing an idealized palindromic ERE. In buffer containing 100 mM KCl, the baculovirus-expressed, purified human ER bound with similar affinity to the consensus ERE and a mutant ERE with a single base pair change per half-site. Above 225 mM KCl, ER exhibited discrimination between the consensus and mutated ERE targets. Between 225 and 275 mM KCl, binding to the consensus ERE was independent of salt concentration and occurred with an equilibrium dissociation constant (Kd) of 1.8 +/- 0.6 nM, whereas binding to the mutant ERE was not detected at ER concentrations below 100 nM under the same conditions. At 300 mM KCl, the Kd for the consensus ERE increased approximately 25-fold, suggesting complex salt concentration dependence. Both estrogen-occupied and unoccupied ER bound to the consensus ERE sequence with similar affinity, indicating that estrogen affects ER activity at a step other than DNA binding. Unlike the full-length ER, the recombinant DNA binding domain of ER did not discriminate between the consensus and mutated ERE sequences even at buffer salt concentrations greater than 200 mM NaCl, suggesting that ER sequences outside the DNA binding domain may be important in promoting specific binding.

Animals↗
PubMed1997

Computerized medication administration records decrease medication occurrences.

Studies have demonstrated that medication errors occur at a number of locations in the continuum between ordering of drug therapy and administration of the medication. Computer management of patient medication profiles offers the opportunity to enhance communication between pharmacists and nurses, and to decrease medication errors and delays in delivery of therapy. A number of authors have postulated that computerization of medication profiles would enhance medication delivery accuracy and timeliness, but no study has demonstrated this improvement. We report the results of a retrospective analysis undertaken to assess the improvements resulting from sharing a computerized medication record. We used a broader definition of medication occurrences that includes the more traditional definition, and averted errors, delays in delivery of medications and information, and disagreements between pharmacy and nursing medication profiles. We compared medication occurrences reported through an existing internal system between two periods; the first when separate pharmacy and nursing medication records were used, and the second period when a shared medication record was used by pharmacy and nursing. Average medication occurrences per admission decreased from 0.1084 to 0.0658 (p < 0.01). Medication occurrences per dose decreased from 0.0005 to 0.0003 (p < 0.01). The use of a shared medication record by pharmacy and nursing led to a statistically significant decrease in medication occurrences. Information shared between the two professions allowed timely resolution of discrepancies in medication orders, leading to better execution of drug therapy, decreased medication occurrences, and increased efficiency.

Clinical Pharmacy Information Systems↗
PubMed1996

Resonance Raman spectroscopic identification of a histidine ligand of b595 and the nature of the ligation of chlorin d in the fully reduced Escherichia coli cytochrome bd oxidase.

Cytochrome bd oxidase is a bacterial terminal oxidase that contains three cofactors: a low-spin heme (b558), a high-spin heme (b595), and a chlorin d. The center of dioxygen reduction has been proposed to be a binuclear b595/d site, whereas b558 is mainly involved in transferring electrons from ubiquinol to the oxidase. Information on the nature of the axial ligands of the three heme centers has come from site-directed mutagenesis and spectroscopy, which have implicated a His/Met coordination for b558 (Spinner, F., Cheesman, M. R., Thomson, A. J., Kaysser, T., Gennis, R. B., Peng, Q., & Peterson, J. (1995) Biochem. J. 308, 641-644; Kaysser, T. M., Ghaim, J. B., Georgiou, C., & Gennis, R. B. (1995) Biochemistry 34, 13491-13501), but the ligands to b595 and d are not known with certainty. In this work, the three heme chromophores of the fully reduced cytochrome bd oxidase are studied individually by selective enhancement of their resonance Raman (rR) spectra at particular excitation wavelengths. The rR spectrum obtained with 413.1-nm excitation is dominated by the bands of the 5cHS b595(2+) cofactor. Excitation close to 560 nm yields a rR spectrum dominated by the 6cLS b558(2+) heme. Wavelengths between these values enhance contributions from both b595(2+) and b558(2+) chromophores. The rR bands of the ferrous chlorin become the major features with red laser excitation (595-650 nm). The rR data indicate that d2+ is a 5cHS system whose axial ligand is either a weakly coordinating protein donor or a water molecule. In the low-frequency region of the 441.6-nm spectrum, we assign a rR band at 225 cm-1 to the (b595)Fe(II)-N(His) stretching vibration, based on its 1.2-cm(-1) upshift in the 54Fe-labeled enzyme. This observation provides the first physical evidence that the proximal ligand of b595 is a histidine. Site-directed mutagenesis had suggested that His 19 is associated with either b595 or d (Fang, H., Lin, R. -J., & Gennis, R. B. (1989) J. Biol. Chem. 264, 8026-8032). On the basis of the present study, we propose that the proximal ligand of b595 is His 19. We have also studied the reaction of cyanide with the fully reduced cytochrome bd oxidase. In approximately 700-fold excess cyanide (approximately 35 mM), the 629-nm UV/vis band of d2+ is blue-shifted to 625 nm and diminished in intensity. However, the rR spectra at each of three different gamma(0) (413.1, 514.5, and 647.1 nm) are identical with or without cyanide, thus indicating that both b595 and d remain as 5cHS species in the presence of CN-. This observation leads to the proposal that a native ligand of ferrous chlorin d is replaced by CN- to form the 5cHS d2+ cyano adduct. These findings corroborate our companion study of the "as-isolated" enzyme in which we proposed a 5cHS d3+ cyano adduct (Sun, J., Osborne, J. P., Kahlow, M. A., Kaysser, T. M., Hill, J. J., Gennis, R. B., & Loehr, T. M. (1995) Biochemistry 34, 12144-12151). To further characterize the unusual and unexpected nature of these proposed high-spin cyanide adducts, we have obtained EPR spectral evidence that binding of cyanide to fully oxidized cytochrome bd oxidase perturbs a spin-state equilibrium in the chlorin d3+ to yield entirely the high-spin form of the cofactor.

Cytochrome a Group↗
PubMed1994

The room temperature reaction of carbon monoxide and oxygen with the cytochrome bd quinol oxidase from Escherichia coli.

When grown under O2-limited conditions, Escherichia coli expresses a cytochrome bd quinol oxidase that has an unusually high affinity for O2. We have studied the reaction of cytochrome bd with CO and O2 by rapid-reaction spectrophotometry. The reduced enzyme forms a photosensitive ferrocytochrome d-CO complex, and following photolysis, CO recombines with the reduced enzyme with a bimolecular rate of 8 x 10(7) M-1 s-1. Reaction of CO-bound enzyme with O2 gives a CO off-rate of 1.6 s-1. The O2 reaction is followed by a flow-flash procedure in which CO-ligated enzyme is mixed with O2, and the reaction commenced by photolysis of cytochrome d-CO. In the presence of O2, two processes are resolved on a time-scale of 300 microseconds. The absorbance at 645 nm first increases at a rate that is dependent on O2 concentration with a value of 2 x 10(9) M-1 s-1. The second phase results in decreased absorbance at 645 nm and increased absorbance at 680 nm. The rate of the second process is independent from O2 concentration above 50 microM O2 and reaches a first-order limit of 1 x 10(4) s-1. A model for the reaction of the cytochrome bd quinol oxidase with O2 is proposed in which an initial ferrocytochrome d-oxy adduct forms, and then decays to a ferryl-oxo species. The oxidation of the low-spin cytochrome b component of the oxidase, monitored at 560 nm, occurs at the same time as the ferryl species forms. We suggest that the suitability of the cytochrome bd quinol oxidase to function at low O2 concentration is conferred by its rapid rate of binding O2.

Carbon Monoxide↗
PubMed1993

Spectroscopic characterization of mutants supports the assignment of histidine-419 as the axial ligand of heme o in the binuclear center of the cytochrome bo ubiquinol oxidase from Escherichia coli.

The bo-type ubiquinol oxidase of Escherichia coli is a member of the superfamily of heme-copper oxidases which also includes the aa3-type cytochrome c oxidases. The oxygen-binding binuclear center of cytochrome bo is located in subunit I and consists of a heme (heme o; heme a3 in the aa3-type oxidases) and a copper (Cu(B)). Previous spectroscopic studies have shown that heme o is bound to the protein via a single histidine residue. Site-directed mutagenesis of conserved histidine residues in subunit I has identified two residues (H284 and H419) which are candidates for the ligand of heme o, while spectroscopic studies of mutants at H284 definitively demonstrated that this residue cannot be the axial ligand. Consequently, the single remaining conserved histidine in subunit I (H419) was assigned as the ligand for the heme of the binuclear center. In this paper, this assignment is tested by characterization of additional mutants in which the putative heme o axial ligand, H419, is replaced by other amino acids. All mutations at H419 result in the loss of enzyme activity. Analyses via UV-visible and Fourier transform infrared spectroscopies reveal that substantial perturbation has occurred at the binuclear center as a result of the amino acid substitutions. In contrast with the wild-type enzyme, the mutant enzymes bind very little carbon monoxide. Three other amino acid residues which are potential ligands for heme o are shown tob e nonessential for enzyme activity. Mutations in these residues do not perturb the UV-visible or FTIR spectroscopic characteristics of the enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Site-directed mutants of the cytochrome bo ubiquinol oxidase of Escherichia coli: amino acid substitutions for two histidines that are putative CuB ligands.

The bo-type ubiquinol oxidase of Escherichia coli is a member of the superfamily of structurally related heme-copper respiratory oxidases. The members of this family, which also includes the aa3-type cytochrome c oxidases, contain at least two heme prosthetic groups, a six-coordinate low-spin heme, and a high-spin heme. The high-spin heme is magnetically coupled to a copper, CuB, forming a binuclear center which is the site of oxygen reduction to water. Vectorial proton translocation across the membrane bilayer appears to be another common feature of this superfamily of oxidases. It has been proposed previously that the two adjacent histidines in putative transmembrane helix VII (H333 and H334 in the E. coli sequence) of the largest subunit of the heme-copper oxidases are ligands to CuB. Previously reported mutagenesis studies of the E. coli bo-type oxidase and the aa3-type oxidase of Rhodobacter sphaeroides supported this model, as substitutions at these two positions produced nonfunctional enzymes but did not perturb the visible spectra of the two heme groups. In this work, six different amino acids, including potential copper-liganding residues, were substituted for H333 and H334 of the E. coli oxidase. All of the mutations resulted in inactive, but assembled, oxidase with both of the heme components present. However, cryogenic Fourier transform infrared (FTIR) spectroscopy of the CO adducts revealed that dramatic changes occur at the binuclear center as a result of each mutation and that CuB appears to be absent.(ABSTRACT TRUNCATED AT 250 WORDS)

Copper↗
PubMed1993

Identity of the axial ligand of the high-spin heme in cytochrome oxidase: spectroscopic characterization of mutants in the bo-type oxidase of Escherichia coli and the aa3-type oxidase of Rhodobacter sphaeroides.

Prokaryotic and eukaryotic cytochrome c oxidases and several bacterial ubiquinol oxidases compose a superfamily of heme-copper oxidases. These enzymes are terminal components of aerobic respiratory chains, the principal energy-generating systems of aerobic organisms. Two such heme-copper oxidases are the aa3-type cytochrome c oxidase of Rhodobacter sphaeroides and the bo-type ubiquinol oxidase of Escherichia coli. These enzymes catalyze the reduction of oxygen to water at a heme-copper binuclear center. Energy conservation is accomplished by coupling electron transfer through the metals of the oxidases to proton translocation across the cellular membrane. The Rb. sphaeroides and E. coli enzymes have previously been utilized in site-directed mutagenesis studies which identified two histidines which bind the low-spin heme (heme a), as well as additional histidine residues which are probable ligands for copper (CuB). However, the histidine that binds the heme of the binuclear center (heme a3) could not be unequivocally identified between two residues (His284 and His419). Additional characterization by Fourier transform infrared spectroscopy of the CO-bound forms of the E. coli enzyme in which His284 is replaced by glycine or leucine demonstrates that these mutations cause only subtle changes to CO bound to the heme of the binuclear center. Resonance Raman spectroscopy of the Rb. sphaeroides enzyme in which His284 is replaced by alanine shows that the iron-histidine stretching mode of heme a3 is maintained, in contrast with the loss of this mode in mutants at His419. These results demonstrate that His284 is not the heme a3 ligand.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Spectroscopic evidence for a heme-heme binuclear center in the cytochrome bd ubiquinol oxidase from Escherichia coli.

The cytochrome bd complex is a ubiquinol oxidase, which is part of the aerobic respiratory chain of Escherichia coli. This enzyme is structurally unrelated to the heme-Cu oxidases such as cytochrome c oxidase. While the cytochrome bd complex contains no copper, it does have three heme prosthetic groups: heme b558, heme b595, and heme d (a chlorin). Heme b558 appears to be involved in the oxidation of quinol, and heme d is known to be the site where oxygen binds and is reduced to water. The role of heme b595, which is high spin, is not known. In this paper, CO is used to probe the oxygen-binding site by use of Fourier transform infrared spectroscopy to monitor the stretching frequency of CO bound to the enzyme. Photodissociation at low temperature (e.g., 20 K) of the CO-heme d adduct results in CO associated with the protein within the heme binding pocket. This photodissociated CO can subsequently relax to form a kinetically trapped CO-heme b595 adduct. The data clearly show that heme d and heme b595 must reside within a common binding pocket in the enzyme. The catalytic active site where oxygen is reduced to water is, thus, properly considered to be a heme d-heme b595 binuclear center. This is analogous to the heme alpha 3-Cu(B) binuclear center in the heme-Cu oxidases. Heme b595 may play roles analogous to those proposed for the Cu(B) component of cytochrome c oxidase.

Binding Sites↗
PubMed1992

Modified, large-scale purification of the cytochrome o complex (bo-type oxidase) of Escherichia coli yields a two heme/one copper terminal oxidase with high specific activity.

The cytochrome o complex is a bo-type ubiquinol oxidase in the aerobic respiratory chain of Escherichia coli. This complex has a close structural and functional relationship with the eukaryotic and prokaryotic aa3-type cytochrome c oxidases. The specific activity, subunit composition, and metal content of the purified cytochrome o complex are not consistent for different preparative protocols reported in the literature. This paper presents a relatively simple preparation of the enzyme starting with a strain of Escherichia coli which overproduces the oxidase. The pure enzyme contains four subunits by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Partial amino acid sequence data confirm the identities of subunit I, II, and III from the SDS-PAGE analysis as the cyoB, cyoA, and cyoC gene products, respectively. A slight modification of the purification protocol yields an oxidase preparation that contains a possible fifth subunit which may be the cyoE gene product. The pure four-subunit enzyme contains 2 equivs of iron but only 1 equiv of copper. There is no electron paramagnetic resonance detectable copper in the purified enzyme. Hence, the equivalent of CuA of the aa3-type cytochrome c oxidases is absent in this quinol oxidase. There is also no zinc in the purified quinol oxidase. Finally, monoclonal antibodies are reported that interact with subunit II. One of these monoclonals inhibits the quinol oxidase activity of the detergent-solubilized, purified oxidase. Hence, although subunit II does not contain CuA and does not interact with cytochrome c, it still must have an important function in the bo-type ubiquinol oxidase.

Amino Acid Sequence↗
PubMed1992

Spectroscopic and genetic evidence for two heme-Cu-containing oxidases in Rhodobacter sphaeroides.

It has recently become evident that many bacterial respiratory oxidases are members of a superfamily that is related to the eukaryotic cytochrome c oxidase. These oxidases catalyze the reduction of oxygen to water at a heme-copper binuclear center. Fourier transform infrared (FTIR) spectroscopy has been used to examine the heme-copper-containing respiratory oxidases of Rhodobacter sphaeroides Ga. This technique monitors the stretching frequency of CO bound at the oxygen binding site and can be used to characterize the oxidases in situ with membrane preparations. Oxidases that have a heme-copper binuclear center are recognizable by FTIR spectroscopy because the bound CO moves from the heme iron to the nearby copper upon photolysis at low temperature, where it exhibits a diagnostic spectrum. The FTIR spectra indicate that the binuclear center of the R. sphaeroides aa3-type cytochrome c oxidase is remarkably similar to that of the bovine mitochondrial oxidase. Upon deletion of the ctaD gene, encoding subunit I of the aa3-type oxidase, substantial cytochrome c oxidase remains in the membranes of aerobically grown R. sphaeroides. This correlates with a second wild-type R. sphaeroides is grown photosynthetically, the chromatophore membranes lack the aa3-type oxidase but have this second heme-copper oxidase. Subunit I of the heme-copper oxidase superfamily contains the binuclear center. Amino acid sequence alignments show that this subunit is structurally very highly conserved among both eukaryotic and prokaryotic species. The polymerase chain reaction was used to show that the chromosome of R. sphaeroides contains at least one other gene that is a homolog of ctaD, the gene encoding subunit I of the aa3-type cytochrome c oxidase.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1989

Heel pain and body weight.

Body weight has been implicated as a factor in plantar heel pain. In this study, a statistically significant correlation between heel pain and increased body weight is documented in a series of consecutive plantar heel pain patients.

Adult↗
PubMed1988

Ulnar compression neuropathy secondary to the anconeus epitrochlearis muscle.

The treatment of the five arms of four patients with ulnar neuropathy at the elbow and an associated anconeus epitrochlearis muscle is presented. Two of these patients had unilateral involvement, one had bilateral neuropathy and bilateral anconeus epitrochlearis muscles, and one had bilateral symptoms, with an anconeus epitrochlearis muscle on the side that was treated by operation. All patients were treated with excision of the anconeus epitrochlearis muscle and cubital tunnel release without anterior transposition of the nerve. All five arms were clinically normal at follow-up 16 to 29 months after operation. Postoperative electrodiagnostic studies on four arms at an average of 9 months after operation showed marked improvement in conduction velocities across the elbow. We recommend simple excision of the anomalous anconeus epitrochlearis muscle when no other cause of ulnar nerve neuropathy at the elbow is identified. Anterior transposition of the nerve seems unnecessary.

Adult↗