Energy transport in closed quantum systems.

We examine energy transport in an ensemble of closed quantum systems driven by stochastic perturbations. One can show that the probability and energy fluxes can be described in terms of quantum advection modes (QAMs) associated with the off-diagonal elements of the density matrix. These QAMs play the role of Landauer channels in a system with discrete energy spectrum and the eigenfunctions that cannot be described as plane waves. In order to determine the type of correlations that exist between the direction and magnitudes of each QAM and the average direction of energy and probability fluxes we have numerically solved the time-dependent Schrödinger equation describing a single particle trapped in a parabolic potential well which is perturbed by stochastic ripples. The ripples serve as a localized energy source and are offset to one side of the potential well. As the result a nonzero net energy flux flows from one part of the potential well to another across the symmetry center of the potential. We find that some modes exhibit positive correlation with the direction of the energy flow. Other modes, that carry a smaller energy per unit of the probability flux, anticorrelate with the energy flow and thus provide a backflow of the probability. The overall picture of energy transport that emerges from our results is very different from the conventional one based on a system with continuous energy spectrum.

Leptodictya tabida (Hemiptera: Tingidae): a potential threat to sugarcane production in Lower Rio Grande Valley of Texas.

Areawide surveys and replicated cultivar trials were conducted in 2001 and 2002 in sugarcane (Saccharum spp.) fields in the Lower Rio Grande Valley of Texas to assess the distribution and incidence of the sugarcane tingid Leptodictya tabida (Herrich-Schaeffer). L. tabida was found in all fields surveyed during both years, infesting 60 and 68% of the plants, respectively. The average percentage of leaves infested was 11% in 2001 and 15% in 2002. In 2001, 'CP70-1133' was the most infested, 'CP72-1210' was the least infested, and intermediate infestation levels were evident in 'CP70-321' and 'TCP87-3388'. In 2002, however, TCP87-3388 and CP70-321 were more heavily infested, and CP71-1240 and CP71-1405 were the least infested. Mean densities of L. tabida recovered per plant varied between 1.2 bugs on CP72-1210 and 5.1 on CP70-1133 in 2001, and in 2002, from zero bugs on CP71-1240 and CP71-1405 to 5.3 on CP72-1210. In the cultivar trials, cultivar differences also were evident in both plant and leaf infestation levels, and the proportion of immatures to total L. tabida populations; 'HoCP91-555' had the lowest L. tabida infestations and 'NCo-310' had the greatest levels in both years. Although >5000 L. tabida from the field were collected and kept in the laboratory, no parasitoids were found. The distribution of the infestations during the surveys and in the field trial evaluations suggested that L. tabida populations have been spreading in sugarcane across the Lower Rio Grande Valley. Potential varietal resistance mechanisms are discussed.

Symptomatic ulnar neural loop at the wrist.

A case report is presented of a patient found at surgery to have an anomalous neural loop of the ulnar nerve at the wrist. The literature is reviewed. Although previous cases have been reported with compressive symptoms or as a coincidental finding we believe that this is the first case reported where symptoms were directly related to the presence of the loop without evidence of a compressive lesion.

Scapholunate fusion in chronic symptomatic scapholunate instability.

Since 1989 scapholunate fusion has been performed on 13 patients with chronic scapholunate instability causing debilitating symptoms. These cases were reviewed at a mean 93 (range, 60-132) months after surgery. Establishing whether bony fusion had been achieved proved extremely difficult even after CT scanning, but fusion was unequivocally achieved in four cases. Ten patients were subjectively satisfied with their treatment. Two patients who had no symptomatic improvement subsequently underwent total wrist arthrodesis. A method of fusing the scaphoid and lunate is described, though we accept that a firm fibrous union may be all that is achieved in most patients. However, this appears sufficient to restore stability with a high patient satisfaction.

Randomized trial of a combination of natural products (cernitin, saw palmetto, B-sitosterol, vitamin E) on symptoms of benign prostatic hyperplasia (BPH).

Because benign prostatic hyperplasia (BPH) is relatively common, it is important to discover safe and effective means to treat this often debilitating perturbation. Accordingly, we examined the effectiveness of a combination of natural products (cernitin, saw palmetto, B-sitosterol, vitamin E) in treating symptoms of BPH. We undertook a randomized, placebo-controlled, double-blind study. Patients were enrolled from 3 urological practices in the USA. 144 subjects were randomized for study. 17 subjects eventually withdrew, leaving 70 patients in the test group and 57 in the placebo group to complete the study. Inclusion criteria consisted of a diagnosis of BPH, no evidence of cancer, and a maximal urinary flow rate between 5 and 15 ml/second. Patients received either placebo or the combined natural products for 3 months. Evaluations were performed via the American Urological Association (AUA) Symptom Index score, urinary flow rate, PSA measurement, and residual bladder volume. Nocturia showed a markedly significant decrease in severity in patients receiving the combined natural products compared to those taking placebo (p < 0.001). Daytime frequency was also lessened significantly (p < 0.04). When the average individual total AUA Symptom Index score in the test group was compared to that in the placebo group at the end of the study, the difference proved highly significant (p < 0.014). PSA measurements, maximal and average urinary flow rates, and residual volumes showed no statistically significant differences. When taken for 3 months, a combination of natural products (cernitin, saw palmetto, B-sitosterol, vitamin E) compared to placebo can significantly lessen nocturia and frequency and diminish overall symptomatology of BPH as indicated by an improvement in the total AUA Symptom Index score. The combination of natural products caused no significant adverse side effects.

Corrective osteotomy of malunited fractures of phalanges and metacarpals.

We have retrospectively reviewed our experience of corrective osteotomies for phalangeal and metacarpal malunions in eleven patients over a 5-year period. Rotational metacarpal malunion treated by metacarpal osteotomy and AO plate fixation can be performed with confidence of achieving a good or excellent result. Phalangeal osteotomy remains a daunting undertaking for most hand surgeons. Our indifferent results are probably due to the inclusion of three intraarticular malunions treated by extraarticular osteotomy. An alternative approach to these malunions may be appropriate.

Effect of whitefly parasitoids on the cuticular lipid composition of Bemisia argentifolii (Homoptera: aleyrodidae) nymphs.

Experiments were conducted to determine the effects of whitefly parasitoids on the cuticular lipid composition of the silverleaf whitefly, Bemisia argentifolii Bellows and Perring [=sweetpotato whitefly, Bemisia tabaci (Gennadius), Biotype B] nymphs. The cuticular lipids of B. argentifolii nymphs that had been attacked by parasitic wasps, either Eretmocerus mundus Mercet or Encarsia pergandiella Howard, were characterized by capillary gas chromatography and CGC-mass spectrometry and the results compared with the cuticular lipids of unparasitized nymphs. Previous studies with B. argentifolii nymphs had shown that wax esters were the major components of the cuticular lipids with lesser amounts of hydrocarbons, long-chain aldehydes, and long-chain alcohols. No appreciable changes in lipid composition were observed for the cuticular lipids of E. pergandiella-parasitized nymphs as compared to unparasitized controls. However, the cuticular lipids from nymphs parasitized by E. mundus contained measurable quantities of two additional components in their hydrocarbon fraction. Analyses and comparisons with an authentic standard indicated that the two hydrocarbons were the even-numbered chain length methyl-branched alkanes, 2-methyltriacontane and 2-methyldotriacontane. The occurrences and possible functions of 2-methylalkanes as cuticular lipid components of insects are discussed and specifically, in regard to host recognition, acceptance, and discrimination by parasitoids. Published 2000 Wiley-Liss, Inc.

Advanced carpal collapse associated with congenital hypoplastic thumb.

We present the long term sequelae of two patients with congenital hypoplastic thumbs. Neither had surgical correction in childhood, but maintained adequate function in their hands. However, both have developed progressive carpal collapse in adulthood, leading to painful wrists.

Is gene deletion in eukaryotes sequence-dependent? A study of nine deletion junctions and nineteen other deletion breakpoints in intron 7 of the human dystrophin gene.

Although large deletions comprise 65% of the mutations that underlie most cases of Duchenne and Becker muscular dystrophies, the DNA sequence characteristics of the deletions and the molecular processes leading to their formation are largely unknown. Intron 7 of the human dystrophin gene is unusually large (110 kb) and a substantial number of deletions have been identified with endpoints within this intron. The distribution of 28 deletion endpoints was mapped to local sequence elements by PCR. The break points were distributed among unique sequence, LINE-1, Alu, MIR, MER and microsatellite sequences with frequencies expected from the frequency of those sequences in the intron. Thus, deletions in this intron are not associated primarily with any one of those sequences in the intron. Nine deletion junctions were amplified and sequenced. Eight were deletions between DNA sequences with minimal homology (0-4 bp) and are therefore unlikely to be products of homologous recombination. In the ninth case, a complex rearrangement was found to be consistent with unequal recombinational exchange between two Alu sequences coupled with a duplication. We have hypothesized that a paucity of matrix attachment regions in this very large intron expanded by the insertion of many mobile elements might provoke a chromatin structure that stimulates deletions (McNaughton et al., 1997, Genomics 40, 294-304). The data presented here are consistent with that idea and demonstrate that the deletion sequences are not usually produced by homologous DNA misalignments.

Factors affecting the outcome in 50 cases of scaphoid nonunion treated with Herbert screw fixation.

Our experience in the treatment of 50 scaphoid nonunions treated with Herbert screw fixation is reviewed. Success rates fell off as the duration of nonunion before treatment increased. However, this appeared to be related to the increased incidence of avascular necrosis with time rather than simply the factor of time alone. In this series the major adverse determinants for outcome were avascular necrosis and a history of previous surgery for nonunion. Failure to graft in a selected group with an intact cartilaginous envelope or a stable firm fibrous union did not affect results. The heterogeneous nature of any series of scaphoid nonunions is emphasized and the difficulties in comparing results with cohorts unmatched for the various adverse factors discussed is stressed.

The evolution of an intron: analysis of a long, deletion-prone intron in the human dystrophin gene.

The sequence of a 112-kb region of the human dystrophin (DMD/BMD) gene encompassing the deletion prone intron 7 (110 kb) and the much shorter intron 8 (1.1 kb) has been determined. Recognizable insertion sequences account for approximately 40% of intron 7. LINE-1 and THE-1/LTR sequences occur in intron 7 with significantly higher frequency than would be expected statistically while Alu sequences are underrepresented. Intron 7 also contains numerous mammalian-wide interspersed repeats, a diverse range of medium reiteration repeats of unknown origin, and a sequence derived from a mariner transposon. By contrast, the shorter intron 8 contains no detectable insertion sequences. Dating of the LI and Alu sequences suggests that intron 7 has approximately doubled in size within the past 130 million years, and comparison with the corresponding intron from the pufferfish (Fugu rubripes) suggests that the intron has expanded some 44-fold over a period of 400 million years. The possible contribution of the insertion elements to the instability of intron 7 is discussed.

The role of arthroscopy in the investigation of wrist disorders.

The findings at arthroscopy of the wrist in 48 consecutive cases carried out over a 4.5 year period have been retrospectively reviewed. In correlating the clinical and arthroscopic findings in the 36 patients with wrist instability and triangular fibrocartilage injuries we found concurrence in 28 of the cases. In the six patients in whom we were unable to make any provisional clinical diagnosis we did not find arthroscopy helpful. Arthroscopy usefully influenced the management in two of the six patients in whom the articular surface was assessed. We feel that a careful clinical examination of the wrist is the mainstay of diagnosis in wrist disorders. Arthroscopy remains useful in selected cases but has a limited specialized role which should continue to be provided from specialist centres.

Phylogenetic relationships among transposon-like elements in human and primate DNA.

A THE-1 sequence in intron 7 of the human dystrophin gene has been found to represent a new subfamily of THE-1 elements. The sequence is closely related to the MstII family of repetitive sequences and is more like single-copy sequences found in the galago genome than any other THE-1 sequence previously reported. This new THE-1 sequence has been compared with two other complete THE-1 sequences and three related long-terminal repeat elements that we have previously found in intron 7 of the dystrophin gene, and with members of the same family from elsewhere in the primate genome. Parsimony and deletion analysis show that the cluster of THE-1 sequences in intron 7 of the dystrophin gene has arisen from at least three individual insertion events, rather than from the insertion and duplication of a single progenitor sequence.

Sequence of a transposon identified as Tn1000 (gamma delta).

We report the complete sequence of a transposon found in a cosmid clone of a human DNA sequence. The transposon is identified as the Escherichia coli transposon Tn1000 (also known as gamma delta) on the basis of the identity of the restriction map of the new sequence with that previously recorded for Tn1000 and homology between parts of the new sequence and that of published fragments of Tn1000 sequence. The transposon, which comprises 5,981 nucleotides including two 35 bp inverted terminal repeat sequences (ITRs), contains three open reading frames. The sequence of the resolvase coding region (tnpR) is identical to that published by others. A second reading frame can be identified as the tnpA gene, coding for the transposase, on the grounds of its strong homology with the corresponding gene from transposon Tn3. The third reading frame has the potential to code for a protein of unknown function containing 698 amino acids.

Simple excision of the trapezium for osteoarthritis of the carpometacarpal joint of the thumb.

We have reviewed the results in 34 patients (39 operations) following simple excision of the trapezium for osteoarthritis of the basal joint of the thumb. The average age at operation was 57 years and the average follow-up was 6 years. All the patients were graded clinically and radiologically and were asked their opinion of the procedure. There was dramatic relief of pain following this procedure. Stability of the thumb was not compromised. When compared to the unoperated side, thumb length, thumb abduction and first web span were similar. There was a reduction in pinch strength (operated 8.1 k.p.a., non-operated 9.6 k.p.a.) and grip strength (operated 15.5 k.p.a., non-operated 19.5 k.p.a.) and an increase in MIP extension (operated 5.4 degrees, non-operated 2.9 degrees) following this procedure but the differences were not statistically significant. 11 patients (32%) had scar hyperaesthesia on testing but this was a clinical problem in two patients only (5%). Simple excision of the trapezium is a satisfactory procedure for the majority of patients with this disorder, but has a long post-operative rehabilitation period.

Perinatal morbidity associated with violence experienced by pregnant women.

OBJECTIVE: We investigated whether physical assault is independently associated with an adverse obstetric outcome. STUDY DESIGN: We compared the perinatal outcomes of 32 indigent women who reported being physically abused during pregnancy with those of 352 control subjects who denied ever being assaulted. Patients were classified into the appropriate category on the basis of a structured interview. Logistic regression analyses were performed to estimate the relative risk of adverse outcome while adjusting for confounders. RESULTS: Women assaulted in the current pregnancy were twice as likely to have preterm labor as compared with those who denied assault. In addition, crude odds ratios showed a twofold increased risk of chorioamnionitis in assault victims. No difference between abused and nonabused women was noted in the prevalence of preterm delivery, pregnancy-induced hypertension, cesarean section, meconium staining, infant birth weight, Apgar scores, intrauterine growth retardation, fetal distress, fetal death, neonatal seizures, sepsis, or admission to the intensive care unit. CONCLUSIONS: This study demonstrates that physical assault during pregnancy is associated with preterm labor and chorioamnionitis. Screening for ongoing assault should be incorporated into routine prenatal care to identify women at risk of complications.

PIP: This study was undertaken to investigate whether physical assault was independently associated with an adverse obstetric outcome. 512 women examined at the low-risk prenatal clinic of the University of Texas Medical Branch in Galveston, Texas, were interviewed. The final cohorts consisted of 32 (7.3%) physically abused women and 352 (80.0%) control subjects without any abuse history. Demographic and socioeconomic differences were found to be insignificant among the respondents. Results revealed that women assaulted in the current pregnancy were twice as likely to have preterm labor as compared with those without assault history. In addition, crude odd ratios showed a twofold increased risk of chorioamnionitis in assault victims. No difference between abused and nonabused women was noted in the prevalence of preterm delivery, pregnancy-induced hypertension, cesarean section, meconium staining, infant birth weight, Apgar scores, intrauterine growth retardation, fetal distress, fetal death, neonatal seizures, sepsis, or admission to the intensive care unit. In conclusion, physical assault was associated with preterm labor and chorioamnionitis and screening for assault must be incorporated during routine prenatal care to identify women at risk of complications.

A cluster of transposon-like repetitive sequences in intron 7 of the human dystrophin gene.

A 32 kilobase-pair fragment of intron 7 of the human dystrophin gene has been sequenced and analysed for the presence of repetitive elements and open reading frames. Two transposon-like human elements (THE-1 sequences), and three intervening, and related, long terminal repeat elements, together with three Alu sequences and a LINE sequence have been identified. These represent an unexpected clustering of highly-repetitive sequences within this single segment of intron DNA. Amplification of a region of chimpanzee genomic DNA by the polymerase chain reaction has provided evidence that at least one of the THE-1 sequences is present in the same position in the chimpanzee genome and the high homology between the human and chimpanzee sequences indicates that this element was fixed within the ancestral genome before the divergence of the two species. The possible role of repetitive, transposon-like sequences in natural mutagenesis of the dystrophin gene is discussed.

Scapho-lunate dissociation occurring with scaphoid fracture.

In the most widely accepted model of injuries to the carpus, scaphoid fracture and scapho-lunate dissociation are held to be mutually exclusive. Four cases in which they occurred together are reported, and the likely mechanism proposed.

Scapho-lunate diastasis: a component of fractures of the distal radius.

Ten cases of fractures of the distal radius associated with scapho-lunate diastasis are reported. The mechanism of injury has been described and an attempt made to analyse the implications in treating such an injury.