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To obtain information about the evolution of the cholinesterases, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in the vertebrates, we investigated the cholinesterase (ChE) activity of the cephalochordate amphioxus (Branchiostoma floridae and Branchiostoma lanceolatum). On the basis of evidence from enzymology, pharmacology, and molecular biology, we conclude that amphioxus possesses two ChE activities and two ChE genes. Two covalent inhibitors of cholinesterases were able to pharmacologically isolate the two activities as drug-sensitive ChE and drug-resistant ChE. Kinetically, in terms of substrate specificity, the drug-sensitive ChE resembles vertebrate AChE, and the drug-resistant ChE resembles the BuChE of cartilaginous and bony fish or the intermediate ChE of protostome invertebrates. We also used the polymerase chain reaction with degenerate oligonucleotide primers and genomic DNA to obtain clones of 1,574 and 1,011 bp corresponding to two cholinesterase genes from amphioxus, which we designated as ChE1 and ChE2. ChE2 codes for an enzyme with an acyl-binding pocket sequence, a portion of the protein that plays an important role in determining substrate specificity, typical of invertebrate ChE. ChE1, which contains a 503-bp intron, encodes a protein with a novel acyl binding site. Phylogenetic analysis of the sequences suggests that the two genes are a result of a duplication event in the lineage leading to amphioxus. We discuss the relevance of our results to the evolution of the cholinesterases in the chordates. Previously, we reported that amphioxus contained a single cholinesterase activity with properties intermediate to AChE and BuChE (Pezzementi et al. [1991] In: Cholinesterases: Structure, Function, Mechanism, Genetics and Cell Biology. J. Massoulié et al., eds. ACS: Washington, D.C., pp. 24-31).

Desmin, the muscle-specific member of the intermediate filament (IF) family, is one of the earliest known myogenic markers in both skeletal muscle and heart. Its expression precedes that of all known muscle proteins including the members of the MyoD family of myogenic helix-loop-helix (mHLH) regulators with the exception of myf5. In mature striated muscle, desmin IFs surround the Z-discs, interlink them together and integrate the contractile apparatus with the sarcolemma and the nucleus. In vitro studies using both antisense RNA and homologous recombination techniques in embryonic stem (ES) cells demonstrated that desmin plays a crucial role during myogenesis, as inhibition of desmin expression blocked myoblast fusion and myotube formation. Both in C2C12 cells and differentiating embryoid bodies, the absence of desmin interferes with the normal myogenic program, as manifested by the inhibition of the mHLH transcription regulators. To investigate the function of desmin in all muscle types in vivo, we generated desmin null mice through homologous recombination. Surprisingly, a considerable number of these mice are viable and fertile, potentially due to compensation by vimentin, nestin or synemin. However, desmin null mice demonstrate a multisystem disorder involving cardiac, skeletal and smooth muscle, beginning early in their postnatal life. Histological and electron microscopic analysis in both heart and skeletal muscle tissues reveals severe disruption of muscle architecture and degeneration. Structural abnormalities include loss of lateral alignment of myofibrils, perturbation of myofibril anchorage to the sarcolemma, abnormal mitochondrial number and organization, and loss of nuclear shape and positioning. Loose cell adhesion and increased intercellular space are prominent defects. The consequences of these abnormalities are most severe in the heart, which exhibits progressive degeneration and necrosis of the myocardium accompanied by extensive calcification. Abnormalities of smooth muscle included hypoplasia and degeneration. There is a direct correlation between severity of damage and muscle usage, possibly due to increased susceptibility to normal mechanical damage and/or to repair deficiency in the absence of desmin. In conclusion, the studies so far have demonstrated that though desmin is absolutely necessary for muscle differentiation in vitro, muscle development can take place in vivo in the absence of this intermediate filament protein. However, desmin seems to play an essential role in the maintenance of myofibril, myofiber and whole muscle tissue structural and functional integrity.

Desmin, the muscle specific intermediate filament (IF) protein encoded by a single gene, is expressed in all muscle tissues. In mature striated muscle, desmin IFs surround the Z-discs, interlink them together and integrate the contractile apparatus with the sarcolemma and the nucleus. To investigate the function of desmin in all three muscle types in vivo, we generated desmin null mice through homologous recombination. Surprisingly, desmin null mice are viable and fertile. However, these mice demonstrated a multisystem disorder involving cardiac, skeletal, and smooth muscle. Histological and electron microscopic analysis in both heart and skeletal muscle tissues revealed severe disruption of muscle architecture and degeneration. Structural abnormalities included loss of lateral alignment of myofibrils and abnormal mitochondrial organization. The consequences of these abnormalities were most severe in the heart, which exhibited progressive degeneration and necrosis of the myocardium accompanied by extensive calcification. Abnormalities of smooth muscle included hypoplasia and degeneration. The present data demonstrate the essential role of desmin in the maintenance of myofibril, myofiber, and whole muscle tissue structural and functional integrity, and show that the absence of desmin leads to muscle degeneration.

A differentiating system based on embryonic stem (ES) cell-derived embryoid bodies (EBs) which recapitulates the in vivo cardiac, skeletal, and smooth muscle myogenesis of mouse embryos was developed and used to investigate the effects of the disruption of the desmin gene on muscle cell differentiation. Wild-type, heterozygous, and homozygous cell lines with the mutated desmin allele were evaluated. Skeletal myogenesis was totally inhibited in desmin null mutant EBs, as manifested by the absence of myotube formation, contractility, and myoD, myogenin, myf5, and myosin heavy chain expression. Smooth muscle formation was also completely blocked in the absence of desmin. On the other hand, there were no obvious effects on cardiomyocyte differentiation in these desmin null mutant EBs. However, reduced desmin expression in EBs heterozygous for the desmin mutation leads to partial inhibition of cardiac muscle formation. These data suggest that in contrast to early cardiocyte differentiation, desmin is indispensable for skeletal and smooth muscle formation.

This study examines the possibility that social support operates as a moderator of cardiovascular reactivity in women. Two models by which social support may operate were examined: the direct effects and buffering models. Twenty-six subjects were exposed to four conditions while playing a video game: two levels of stress (low, high) and two levels of social support (alone, together). Blood pressure and heart rate were monitored continuously. Ratings of stress were obtained for each condition. Results indicated that the support manipulation produced significant main effects for diastolic blood pressure and stress ratings, with lower diastolic blood pressure and ratings observed in the "together" condition, and that the interaction between support and stress produced lower reactivity for the cardiovascular measures in the high stress (but not the low stress) condition. No interaction was found for the stress ratings. We conclude that the results provide support for both the buffering and direct effects models. Implications concerning the (within-subjects) design of the study and the stress ratings are discussed.

Maternal mortality rates (or ratios) are widely used as one indicator of the quality of medical care. There has been concern that conclusions may be drawn from unreliable data. A survey of practices in European countries confirms that there are differences in interpretation of definitions and evidence of significant under-reporting in official returns of vital statistics. Actual and potential sources of error are identified and a need for greater precision and uniformity of data collection is established.

The muscle-specific intermediate filament protein, desmin, is one of the earliest myogenic markers whose functional role during myogenic commitment and differentiation is unknown. Sequence comparison of the presently isolated and fully characterized mouse desmin cDNA clones revealed a single domain of polypeptide similarity between desmin and the basic and helix-loop-helix region of members of the myoD family myogenic regulators. This further substantiated the need to search for the function of desmin. Constructs designed to express anti-sense desmin RNA were used to obtain stably transfected C2C12 myoblast cell lines. Several lines were obtained where expression of the anti-sense desmin RNA inhibited the expression of desmin RNA and protein down to basal levels. As a consequence, the differentiation of these myoblasts was blocked; complete inhibition of myoblast fusion and myotube formation was observed. Rescue of the normal phenotype was achieved either by spontaneous revertants, or by overexpression of the desmin sense RNA in the defective cell lines. In several of the cell lines obtained, inhibition of desmin expression was followed by differential inhibition of the myogenic regulators myoD and/or myogenin, depending on the stage and extent of desmin inhibition in these cells. These data suggested that myogenesis is modulated by at least more than one pathway and desmin, which so far was believed to be merely an architectural protein, seems to play a key role in this process.

An audit of facilities recommended to be available in consultant obstetric units (COUs) in the United Kingdom (UK) received responses from 248 (95%) of all 260 COUs. Of the respondents, 86% were on the site of an acute general hospital, 76% had an intensive therapy unit on site, and 87% had a blood bank on site. Eighty-two per cent had a protocol for management of massive haemorrhage, and 91% had a local protocol for the management of severe pre-eclampsia/eclampsia. The development of Regional protocols and advisory centres for the management of hypertensive disorders is at present fragmentary. Purchasers and providers should give urgent attention to correcting remaining deficiencies, and the availability of recommended facilities and protocols should be taken into account when units are assessed for recognition for training.

A formal 44-month clinical evaluation was conducted to determine the suitability of selected electronic equipment for use in high-level quadriplegia. A total of 52 traumatic high-level quadriplegic patients (C-2 to C-5,6) participated in the testing of 13 commercial electronic assistive devices including 8 environmental control units, 1 self-contained telephone, and 4 typewriter systems. Most devices were pneumatically ("breath") controlled. Devices were tested in an occupational therapy laboratory, bedside, and homes. Testing yielded data on device reliability, suitability, and acceptance by patients.

The local delivery of human services is currently receiving national emphasis. The expectation is that community-based services shall be provided with a minimum of duplication and with maximum efficiency, achieved partly by interdisciplinary and interorganizational cooperation. This emphasis was appropriately facilitated in the mid-1970s through the availability of the Mental Health Initiative grants. The grants, initiated by the Bureau of Community Health Services in conjunction with the National Institute of Mental Health, Public Health Service, promoted the increased availability of mental health services through formal linkages between community mental health centers and primary health care programs. One such successful linkage was between a small primary health care center and a nonfederally funded, multicounty, mental health center in northwest Illinois. Initiated in September 1980, the services of the linkage project included direct clinical mental health services delivered at the primary health care center site, consultation and education activities, and the coordination of interagency services. The project patients differed from the general clients of the mental health center in demographic characteristics, source of referral, and diagnoses. The key elements in successful linkages and the achievement of goals are analyzed. The experience of the linkage project is relevant to the 1980s. The project was prematurely ended after 14 months. Reduction in Federal funds severely cut support for the primary health care center, and the depressed local economy could not match the withdrawn Federal funds.

In 100 consecutive adults who came to a sleep disorders center complaining of repeated nocturnal injury, polysomnographic study identified five disorders: night terrors/sleepwalking (N = 54), REM sleep behavior disorder (N = 36), dissociative disorders (N = 7), nocturnal seizures (N = 2), and sleep apnea (N = 1). Ninety-five patients sustained ecchymoses, 30 had lacerations, and nine had fractures. DSM-III axis I disorders (past or current) were found in 48.1% of the group with night terrors/sleepwalking and in 30.6% of the group with REM sleep behavior disorder; these were mainly affective disorders. In these two groups, clonazepam controlled the symptoms of 51 of the 61 patients to whom it was given.